Somatom sessions 25

SOM

AT

OM

Ses

sio

ns

RSN

A-E

dit

ion

No

vem

be

r 2

009

25

SUBSCRIBE NOW!

– and get your free copy of future

SOMATOM Sessions! Interesting information

from the world of computed tomography – gratis

to your desk. Send us this postcard, or subscribe

online at www.siemens.com/ct-news

SOM

AT

OM

Sess

ion

s

Patient‘s safety domi-nates physicians work. In Computed Tomo-graphy that means achieving highest image quality with the absolute minimum dose possible. Over the years, Siemens has been highly creative in integrating dose-reduction innovations into their CT-scanners.

Siem

ens

AG

Med

ical

Sol

uti

ons

CC

CB

Hen

kest

raße

127

910

52 E

rlan

gen

Ger

man

y

On account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/All of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

Siemens reserves the right to modify the design, packaging, specifications and options described herein without prior notice. Please contact your local Siemens sales representative for the most current information.

Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.

www.siemens.com/healthcare-magazine

Global Business Unit

Siemens AGMedical SolutionsComputed TomographySiemensstraße 1DE-91301 ForchheimGermanyPhone: +49 9191 18 - 0www.siemens.com/healthcare

Local Contact Information

Asia/Pacific:Siemens Medical SolutionsAsia Pacific HeadquartersThe Siemens Center60 MacPherson RoadSingapore 348615Phone: +65 9622 - 2026www.siemens.com/healthcare

Canada:Siemens Canada LimitedMedical Solutions2185 Derry Road WestMississauga ON L5N 7A6CanadaPhone: +1 905 819 - 5800www.siemens.com/healthcare

Europe/Africa/Middle East:Siemens AGMedical SolutionsHenkestraße 127D-91052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Latin America:Siemens S.A.Medical SolutionsAvenida de Pte. Julio A. Roca No 516, Piso 7C1067ABN Buenos Aires ArgentinaPhone: +54 11 4340 - 8400www.siemens.com/healthcare

USA:Siemens Medical Solutions U.S.A., Inc.51 Valley Stream ParkwayMalvern, PA 19355-1406USAPhone: +1-888-826 - 9702www.siemens.com/healthcare

Global SiemensHealthcare Headquarters

Siemens AGHealthcare SectorHenkestraße 12791052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Global Siemens Headquarters

Siemens AGWittelsbacherplatz 280333 MuenchenGermany

Order No. A91CT-00973-41M1-7600 | Printed in Germany | CC CT 00973 ZS 1109/41.5 | © 11.2009, Siemens AG

The Difference in Computed Tomography

SOMATOM Sessions

25

Issue Number 25/November 2009RSNA-Edition I November 29th – December 04th, 2009

Cover Story Mission Possible: Reducing Radiation Dose in CTPage 6

News International CT Image Contest – Highest Image Quality at Lowest DosePage 17

Business Lowest Dose Motivates PurchasePage 24

Clinical OutcomesDose Neutral Dual Energy Carotid CTA with SOMATOM Defi nition FlashPage 34

Science Analysis of DNA Double-Strand Breaks Promises New View of Dosimetry in CTPage 52

mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmSSSSSSv dddddddddddddoooooooooooooooooooosssssssssssssssssssseeee

2 SOMATOM Sessions · November 2009 · www.siemens.com/healthcare-magazine

Editorial

“For us and our customers, patient safety means achieving highest quality images with the absolute minimum dose possible.”Sami Atiya, PhD, Chief Executive Officer, Business Unit Computed Tomography, Siemens Healthcare, Forchheim, Germany

Cover Page: No breath hold and no anesthesia was necessary in this pediatric imaging with 0.37s scan time, by using only 1 mSv. Courtesy of University of Erlangen-Nuremberg, Erlangen, Germany

“Reducing radiation dose has always been a concern for Siemens.”

Thomas Flohr, PhD, Director of CT Physics and Applications, Siemens Healthcare, Germany

Yes, I consen

t to the above in

formation

being u

sed for fu

ture con

tact regarding produ

ct updates an

d other

importan

t new

s from Siem

ens.

Please print clearly!

Sub

scriptio

n

un

subscribe from

info service

Stay up

to d

ate with

the latest in

form

ation

Reg

ister for:

the m

onth

ly health

care e-new

sletter

Please enter yo

ur b

usin

ess add

ress

Institu

tion

Departm

ent

Fun

ction

Title

Nam

e

Street

Postal Code

City

State

Cou

ntry

E-mail

Please inclu

de m

e in yo

ur m

ailing

list for th

e fo

llow

ing

Siemen

s Health

care custo

mer m

agazin

e(s):

Medical Solu

tions

MA

GN

ETOM

Flash

SOM

ATOM

Sessions

AX

IOM

Inn

ovations

Responsible for Contents: André Hartung

Editorial Board: Andreas Blaha Andreas Fischer Thomas Flohr, PhD Klaudija Ivkovic Axel Lorz Jens Scharnagl Stefan TheesenHeiko Tuttas Alexander Zimmermann

Authors of this Issue:S. Alibek, MD, Institute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany

H. Alkadhi, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

T. Asami, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

F. Bamberg, MD, MPH, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 35,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their appli-cation as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and discusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the prac-tice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not in-tended by Siemens Medical Solutions to be used for any purpose in that regard.

A. Becker, MD, Department of Medicine, Cardiology Division, University of Munich, Campus Großhadern

F.Civaia, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

G. Feuchtner, MD, Institute of Diagnostic Radiol-ogy, University Hospital Zurich, Zurich, Switzerland

E. Hendrich, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

K. Kichikawa, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan

S. Kitano, MD, Department of Radiology, Nara Medical University, Nara, Japan

M. Kuefner, MD, Institute of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany

T. Lee, MD, Department of Radiology, Bringham and Women’s Hospital, Boston, USA

M. Lell, MD, Institute of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany

S. Leschka, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

S. Martinoff, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

T. Morita, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

S. Mukundan Jr., MD, PhD, Department of Radi-ology, Bringham and Women’s Hospital, Boston, USA

T. Murakami, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

K. Nikolaou, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

P. Rossi, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

S. Rusek, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

B. Ruzsics, MD, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA

H. Saeki, MD, Department of Cardiovascular Internal Medicine, Saiseikai Matsuyama Hospital, Matsuyama, Japan

J. Schoepf, MD, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA

A. Sodickson, MD, PhD, Department of Radiolo-gy, Bringham and Women’s Hospital, Boston, USA

G. Staatz, MD, Section Pediatric Radiology, Insti-tute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany

J. Takahama, MD, Department of Radiology, Nara Medical University, Nara, Japan

H. Tanaka, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

T. Taoka, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan

K. Watanabe, MD, Department of Cardiovascular Internal Medicine, Saiseikai Matsuyama Hospital, Matsuyama, Japan

M. Yamamoto, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

Catherine Carrington, freelance author, Tony DeLisa, freelance author, Amy K. Erickson, medi-cal journalist Sameh Fahmey, medical journalist, Eric Johnson, freelance technolgy and business writer, Hildegard Kaulen, PhD, freelance scien-tific journalist Oliver Klaffke, freelance scientific journalist, Justus Krüger, freelance author

Peter Aulbach; Andreas Blaha; Steven Bell; Ivo Driesser; Kerstin Fellenzer; Thomas Flohr, PhD; Jan Freund; Tanja Gassert; Loke Gie-Haw; Julia Kern-Stoll; Ernst Klotz; Carolin Knecht; Rami Kusa-ma; Marion Meusel; Jakub Mochon; Karen Sch-weizer; Peter Seitz; Heike Theessen; Stefan Wünsch; PhD; all Siemens Healthcare

Photo Credits: Stephan Sahm, Tina Ruisinger, Peter Rigaud/Shotview, Stefen Chow, Ryan Pyle, Frank Bauer

Production: Norbert Moser, Kerstin Putzer,Siemens AG, Healthcare

Design and Editorial Consulting:Independent Medien-Design, Munich, GermanyIn cooperation with Primafila AG, Zurich, Switzerland, Managing Editor: Christa Löberbau-er, Photo Editor: Susanne Nips, Layout: Claudia Diem, Mathias Frisch, All at: Widenmayerstraße 16, 80538 Munich, Germany

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole re-sponsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, provid-ed the customary bibliographical data such as author’s name and title of the con-tribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and informa-tion are always welcome; they are carefully examined and submitted to the edito-rial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

SOMATOM Sessions – IMPRINT© 2009 by Siemens AG, Berlin and MunichAll Rights Reserved

Publisher:Siemens AGHealthcare SectorBusiness Unit Computed TomographySiemensstraße 1, 91301 Forchheim, Germany

Monika Demuth, PhD ([email protected])

Stefan Wünsch, PhD([email protected])

SOMATOM Sessions · November 2009 · www.siemens.com/healthcare-magazine 63

Imprint

Chief Editors:

SOMATOM Sessions is also available on the internet: www.siemens.com/SOMATOMWorld

Editorial

Dear Reader, Siemens has always been the innovation leader in research and development of medical imaging. But this leadership has always been firmly anchored in the be-lief that advanced technology needs to be helpful in clinical routine. Such im-provements must offer advantages to both medical personnel and patients in the following areas: faster, safer and more comfortable exams, improved diagnostic accuracy, earlier detection of pathologies, efficient workflow and improved healthcare for patients.

Our success has always been based upon listening to the needs and opin-ions of our customers – physicians and specialists from around the world work-ing in the various medical facilities. We have integrated the best of this feedback into our research and development. Patient safety has consistently domi-nated this feedback. And, in computed tomography (CT), patient safety means highest image quality at lowest dose. Our dedication to this principle has led us to develop our unique CARE program – “Combined Applications to Reduce Exposure” – that is the cornerstone of our research and development philo-sophy. This principle coordinates and compliments the ALARA principle, “As Low As Reasonably Achievable.” But Siemens goes one step further and insists on respecting these two princi-ples without loss of image integrity.

Over the years, Siemens has been highly creative in integrating dose-reduction

innovations into CT imaging products. The last significant milestone along this path was the introduction of the SOMATOM® Definition Flash Scanner at the RSNA 2008, amazing the entire medical imaging industry with the in-credible scan speed and low-dose with highest image quality. This highly suc-cessful product has caused a paradigm change in the CT playing field and is just beginning to establish itself and prove its full potential in clinical routine.

But our efforts to offer both medical personnel and patients the ultimate in safety, comfort and healthcare did not end there. At this year’s RSNA, we will introduce IRIS – “Iterative Reconstruction in Image Space” – a new image recon-struction algorithm that beautifully and efficiently expands the capabilities of the high-end SOMATOM Definition family. IRIS promises up to 60% dose reduction in addition to the already remarkable reductions achieved with other Siemens products, opening up entirely new applications for CT in clini-cal routine. Another quantum leap in dose reduction and image quality is on the CT horizon.

Our cover story in this issue includes a summary of all the successful dose-reducing methods achieved by Siemens over the years. Our goal for the future is to continuously reduce dose while improving image quality and here we accept no compromise. We have dedi-cated this issue of SOMATOM Sessions

André Hartung, Vice President

Marketing and SalesBusiness Unit CT,

Siemens Healthcare

André Hartung


to dose reduction so that you, the reader, can experience in the different articles just how seriously we take our commitment, “better care for our patients – providing answers to life’s most difficult questions.”

In addition to optimum healthcare and safety for patients, another obligation remains close to our hearts: to provide the best possible working conditions for physicians and other medical personnel regarding efficient workflow, networked communications and keeping up with state-of-the-art developments in the CT arena. Viewed from our customer’s standpoint, this translates to, “My cases, ready; My place, networked; My needs, anticipated.” Today, when a single scan can bring up 2,500 images and reveal numerous pathologies that require different diagnostic and examination methods, an integrated, efficient and automated data management system is absolutely necessary. Siemens has recognized and met this challenge with syngo.via*, our revolutionary, crossmodality software solution that can fast-track your diagnostic workflow to an incredible degree. Read the amazing details in the special supplement to this RSNA issue of SOMATOM Sessions.

Good reading.Sincerely,

*syngo.via can be used as a standalone device or together with a variety of syngo.via based software options, which are medical devices in their owen rights.


Content

Cover Story

6 Mission Possible: Reducing Radiation Dose in CT

News

16 Interactive Breath-Hold Control (IBC) System from the Mayo Clinic is now Available Through Siemens

16 SOMATOM Emotion Facelift 17 International CT Image Contest –

Highest Image Quality at Lowest Radiation Dose

18 New Software Versions for the SOMATOM Definition Family

19 Flash Cardio Dose Saving Capabili-ties Inspire Researchers to Launch PROTECTION IV Trial

20 RSNA 2009 – Arena for SOMATOM Definition Flash Publications

21 syngo 2009A – a New Era for Routine and Advanced Diagnostic Imaging

22 Leading Technology in Rural Hospital

Cover Story

Content

6 Lots of people talk about radiation dose and CT. But for more than a decade, Siemens Healthcare has made dose reduction a mission. The result: an impressive portfolio of innovations in scanner hardware, software, and imaging protocols that together have cut patient radia-tion exposure to a fraction of what it once was. Read more about re-cently requested feedback on some of the most important of these inno-vations from physicians in Germany and the U.S.A. who have had experi-ence with them.

24Lowest Dose Motivates Purchase

6 Mission Possible: Reducing Radiation Dose in CT


Content

Oncology 40 SOMATOM Definition Flash: Ruling

out Cystic Fibrosis (CF) in a Pediatric Patient – Scan in 0.56 Seconds at 1 mSv

Neurology 42 Moyamoya Disease: Whole Brain

Perfusion CT

Acute Care 44 SOMATOM Definition Flash Provides

the Entire Extension of Aortic Dis-section in Just 2 Seconds Scan Time

46 Dual Energy CT Imaging of Chronic Pulmonary Embolism

Science

48 Dose-Optimized CAD Diagnostics 50 First Study Results Using High-Pitch

Spiral Acquisition in the Dual Source SOMATOM Definition Flash CT

52 Analysis of DNA Double-Strand Breaks Promises New View of Dosimetry in CT

Business

24 Lowest Dose Motivates Purchase 26 RIPIT to the Rescue: A New Protocol

for Trauma Imaging 28 Payback Time: How New CTs Justify

the Investment

Clinical Results

Cardio-Vascular 30 Heart Perfused Blood Volume with

SOMATOM Definition Dual Energy Scanning

32 SOMATOM Definition Flash: Dynamic Myocardial Stress-Perfusion

34 Dose Neutral Dual Energy Carotid CTA with SOMATOM Definition Flash

36 SOMATOM Definition Flash Follow-up Examination After Stent Implan-tation for Ruptured Aneurysm

38 Takayasu Arteritis with Atypical Aortic Coarctation: Follow-up Exam with Dual Energy CT

Life

54 Funding to Maintain, Improve, and Expand Services in an Uncertain Economy

55 TubeGuard: Proactive Tube Failure Prediction

56 State-of-the-Art Training 57 “Discover. Try. Buy.” a New Portal

for Individually Expanding Clinical Capabilities

58 CT 2010 – The Congress 58 How to Perform a Cardiac Scan with

Less than 1 mSv 59 Free DVD of the SOMATOM World

Summit 2009 in Valencia 59 Frequently Asked Questions 60 New Workshop Format: Diagnosis

of Congenital Heart Defects 60 Clinical Workshops 2010 61 Upcoming Events & Congresses 62 Siemens Healthcare – Customer

Magazines 63 Imprint

44 SOMATOM Definition Flash Provides the Entire Extension of Aortic Dissection

in Just 2 Seconds Scan Time

40 Ruling out Cystic Fibrosis (CF) in a Pediatric Patient – Scan in 0.56 Seconds at 1mSv


Topic

Mission Possible: Reducing Radiation Dose in CT Over the past decade, Siemens has been a pioneer in creating a host of inno-vative technical features that signifi cantly reduce radiation exposure in CT scans. SOMATOM Sessions recently requested feedback on some of the most important of these innovations from physicians in Germany and the U.S.A. who have had experience with them.

By Catherine Carrington

Lots of people talk about radiation dose and CT. But for more than a decade, Siemens Healthcare has made dose re-duction a mission. The result: an impres-sive portfolio of innovations in scanner hardware, software, and imaging proto-

cols that together have cut patient radia-tion exposure to a fraction of what it once was. “Reducing radiation dose has always been a concern for Siemens,” says Thomas Flohr, PhD, Director of CT Physics and

Applications for Siemens Healthcare in Forchheim, Germany. “CT is the imaging modality of choice in many situations, and it would be used even more if not for the concern about radiation dose.”Siemens’ focus was intensified in the late

CARE Dose4D

Up to 68 %

1994

Adaptive ECG-Pulsing

Up to 50 %

1999

Pediatric 80 kV Protocols

Up to 50 %

2002

UFC

Up to 30 %

1997

HandCARE

Up to 70 %

1999

X-ray off

X-ray on

X-ray

Light

UFC

DSCT

2005

Up to 50 %

t

Siemens‘ Dose Saving features


Topic

spiral cardiac CT scans, ECG-pulsing maintains nominal tube current only during targeted phases of the cardiac cycle, markedly reducing tube current during phases that will not be used for image reconstruction. Dose savings: 30% to 50%.■ 2005: Introduction of the SOMATOM® Definition Dual Source CT scanner, which offers further dose efficiencies in cardiac CT through faster scanning, Adaptive ECG-Pulsing, and automated adaptation of table speed to heart rate. Dose savings: up to 50%, compared to single source CT.■ 2007: Introduction of the Adaptive Cardio Sequence, a prospective ECG-triggered “step and shoot” technique that reduces the average dose for CT coronary angiography to about 2.5 mSv.■ 2007: Introduction of the Adaptive Dose Shield, a technique of asymmetric collimator control that eliminates over-scanning at the beginning and end of the CT spiral. Depending on the length of the scan, it reduces dose by 5% to 25%.

■ 2008: Introduction of the SOMATOM Definition Flash CT scanner. With dual detectors and a table speed of up to 45 cm/s, the Flash cuts radiation dose for coronary CT angiography to less than 1 mSv in many patients.■ 2008: Introduction of X-CARE, organ-based dose modulation that reduces out-put of the X-ray tube when it is directly in front of the breast and other dose-sensi-tive organs, such as the thyroid gland and eye lens. Reduces radiation dose to the breast by 30% to 40%. ■ 2009: Introduction of Iterative Reconstruction in Image Space (IRIS). By “cleaning up” image noise, iterative reconstruction makes it possible to reduce radiation dose by up to 60% and still produce high-quality images. Several dose-reduction strategies de-serve special attention, including CARE Dose4D, the Adaptive Dose Shield, the SOMATOM Definition Flash CT scanner, and IRIS. Each of these is an example not only of Siemens’ commitment to mini-mizing radiation exposure but also its track record of innovation.

1990s, when the company began to systematically search for new ways to reduce radiation dose. A timeline shows not only how relentless Siemens has been in pursuing this goal over the years, but also how creative Siemens Research & Development was. Key milestones in-clude:

■ 1994: Introduction of DOM, later extended to CARE Dose4D, a fully auto-mated, real-time, anatomical dose modulation technology that reduces radiation dose, depending on the area of the body, by 20% to 68% – without degrading image quality.■ 1997: Introduction of an ultra-fast ceramic (UFC) detector designed with a new gadolinium-oxy-sulfite scintillator. The UFC detector – still a key component of multidetector and Dual Source CT systems – cut radiation dose by 30% when compared to previous generations of CT detectors. ■ 1999: Introduction of ECG-pulsing, a technique that synchronizes tube current to the electrocardiogram. Used during

Adaptive Cardio Sequence

2007

Flash Spiral

< 1 mSv Cardio

2008

4D Noise Reduction

Up to 50 %

2008

Iterative Reconstruction in Image Space (IRIS)

Up to 60 %

2009

Adaptive Dose Shield

Up to 25 %

2007

Selective Photon Shield

No dose penalty

2008

X-CARE

Up to 40 %

2008

140 kVAttenuation A

80 kVAttenuation B

Selective Photon Shield

X-ray off

X-ray onDose Shield

Dose Shield

1–3 mSv Cardio

Compare

Image data recon

Image correction

Master recon

Vol

< 1 sec

Tube 1 Tube 2

Image data recon

Image correction


Coverstory

CARE Dose4D

Determining the right tube current and, therefore, the right radiation dose, has always been crucial, says Marilyn J. Siegel, MD, Professor of Radiology and Pediatrics at the Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA. But achieving that goal was much more difficult before CARE Dose4D, because adjustments in tube current had to be made empirically. “CARE Dose4D has really been a great advantage for a number of reasons,” Siegel says. “We get great image quality, reduced dose, and increased patient comfort. And it’s automated, so it’s easier for the technologist.” CARE Dose4D automatically adapts radi-ation dose to the size and shape of the patient, achieving optimal tube current modulation in two ways. First, tube current is varied on the basis of a topo-gram, by comparing the actual patient to a “standard-sized” patient. As might be expected, tube current is increased for larger patients and reduced for small-er patients. Differences in attenuation in distinct body regions are taken into account. For example, in an adult patient, 140 mAs might be needed in the shoulder region, whereas 55 mAs would be sufficient in the thorax, 110 mAs in the abdomen, and 130 mAs in the pelvis. In addition, real-time angular dose modulation measures the actual attenu-ation in the patient during the scan and adjusts tube current accordingly – not only for different body regions, but also for different angles during rotation. This

is particularly important in efficiently reducing dose in the shoulder and pelvic region, where the lateral attenuation is much higher than the anterior-posterior attenuation. Siemens has further refined this process with CARE Dose4D. Clinical experience has shown that the relationship between optimal tube current and patient size is not linear. Larger patients clearly need a higher dose than average-sized patients, but they also have more body fat, which increases tissue contrast. Smaller patients

need a lower dose than average-sized patients, but they have less fat and less tissue contrast, which would result in noisy images if the dose were too low. Therefore, during real-time dose modula-tion, CARE Dose4D reduces radiation dose less than might be expected for smaller patients, while increasing the dose less than might be expected for larger patients. This maintains excellent diag-nostic image quality while achieving an optimal radiation dose. “CARE Dose4D is different from dose modulation approaches used by other vendors,” says Flohr. “It uses measured attenuation data in real time, not just information from topograms; it makes use of a wide mA-range; and it can fine-tune dose on the fly.”Nowhere is CARE Dose4D more impor-tant than in pediatric imaging, where the risk associated with radiation expo-sure is many times higher in children than in adults. A child’s smaller body absorbs more of the radiation dose than does a larger body. In addition, the can-cer induction risk is higher in children, because they have a longer lifespan ahead of them. At the same time, because children’s anatomy is smaller it can be more difficult to visualize.“With children, you want as low a dose as possible but also excellent spatial resolu-tion,” explains Siegel. “CARE Dose4D allows us to reduce radiation exposure in all three planes without impairing diag-nostic image quality, and that’s key.”Publications in scientific journals have shown that in adults, CARE Dose4D reduces radiation dose by 68% in the cervical spine, 37% in the lumbar spine,

“With children, you want as low a dose as possible but also excellent spatial resolution. CARE Dose4D allows us to reduce radiation exposure in all three planes without impairing diagnostic image quality.”

Marilyn J. Siegel, MD, Professor of Radiology and Pediatrics at the Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri, USA

“There’s more and more awareness about the amount of radiation used for CT scanning. Siemens has thoroughly looked into this and is one of the fi rst vendors to implement the tools we need to improve our scanning.”

Christoph Becker, MD, Professor of Radio-logy and Section Chief of CT and PET/CT at Munich University Hospital in Germany


Topic

1 Instead of just taking into account the patient’s external dimensions and apparent size, CARE Dose4D analyzes the cross-sectional anatomy in real-time and adjusts the emitted X-ray dose accordingly – providing excellent image quality with minimized exposure.

CARE Dose4D

mAs for constant image noise

Quality ref. mAs

75 kg reference patient

180

160

140

120

100

80

60

40

20

0200 400 600 800

Body Size (lo/l)

mA

s

1000 1200 1400 1600 1800 2000

1600 mA

20 mA

X-ray dose

Slice position

Real-time angular dose modulation

Reduced dose level based on topogram

Scan with constant mA

1


Coverstory

30% in the thorax, and 38% in the abdo-men and pelvis. In pediatric scans of the heart, a 58% dose reduction has been reported for CARE Dose4D.1

Adaptive Dose ShieldIn spiral CT, it is routine to do an extra half-rotation of the gantry before and after each scan, fully irradiating the detector throughout, even though only part of the acquired data is necessary. As a result, the wide-cone beam exposes tissue that will never be part of recon-structed images. Until recently, no one gave much thought to this needless radi-ation exposure to patients. Such “over-scanning” beyond the targeted scan range was simply accepted as an in-evitable part of spiral CT. Siemens took a fresh look at the problem and, in 2007, introduced the Adaptive Dose Shield, a technology based on pre-cise, fast, and independent movement of both collimator blades. Instead of ex-posing patients to unnecessary radiation, the Adaptive Dose Shield asymmetrically

opens and closes collimators at the be-ginning and end of each scan, tempo-rarily blocking those parts of the X-ray beam that are not used for image recon-struction. As a result, only the targeted tissue is irradiated. Like many other dose-saving innovations, it is a feature pio-neered by Siemens.“There’s more and more awareness about the amount of radiation used for CT scanning,” says Christoph Becker, MD, Professor of Radiology and Section Chief of CT and PET/CT at Munich University Hospital in Germany. “Siemens has thor-oughly looked into this and is one of the first vendors to implement the tools we need to improve our scanning.” At Munich University Hospital, Becker has two Siemens scanners equipped with an Adaptive Dose Shield, the SOMATOM Definition AS+ and the SOMATOM Definition Flash. Although the Adaptive Dose Shield reduces the radiation dose in every study, the savings are especially notable over shorter scan ranges. Dose savings can reach 25% or more in cardiac imaging, for example. The Adaptive Dose Shield is especially well suited to pediatric imaging. “In any circumstance in which children have to be investigated, I would always prefer to use a scanner with the Adaptive Dose Shield,” Becker says. “It’s always on, and it always reduces the radiation dose.”

Flash At the German Heart Center, Jörg Haus-leiter, MD, has been using a SOMATOM Definition Flash CT scanner since April. With this revolutionary scanner, he can image the heart in a quarter of a single heart beat. Equally impressive, he has been able to achieve a radiation dose of 1mSv or less in a large proportion of patients undergoing CT coronary angio-graphy. “That’s unbeatable compared to other CT scanners,” says Hausleiter, an Associate Professor of Medicine at the Munich-based hospital. The SOMATOM Definition Flash gets its name from its flash-fast speed. Equipped with two detectors, two X-ray sources, and a gantry that rotates in 0.28 sec-onds, the scanner boasts a temporal resolution of just 75 ms. Moreover,

thanks to an innovation unique to the SOMATOM Definition Flash, the patient table no longer slowly inches forward during scanning. Instead, in low-dose Flash Spiral mode, the table can glide along at 45 cm/s while the scanner integrates data from both detectors, achieving a gap-free scan even though each spiral is wide open. Still, according to Hausleiter, the key question is whether excellent image quality can be achieved at such a high scan speed and low dose. With the SOMATOM Definition Flash, the answer is clearly yes. “This ultra-low dose was never possible before, but with this scan-ner – with its high temporal resolution and improvements in the X-ray tube and detector – it is now possible,” he says.Of the first 100 coronary CT scans per-formed on the Definition Flash at the German Heart Center, more than 70% could be done in Flash mode. As a result, the average radiation dose for all coro-nary CT scans – including longer scans needed for presurgical evaluation and triple rule-out studies – dropped from a median of 5 to 7 mSv down to 1.8 mSv. Of the 70% of patients scanned in Flash

“This ultra-low dose was never possible before, but with SOMATOM Defi nition Flash – with its high temporal reso-lution and improve-ments in the X-ray tube and detector – it is now possible.”

Jörg Hausleiter, MD, Cardiologist, Associate Professor of Medicine, German Heart Center, Munich, Germany

“With Siemens Iterative Reconstruction I can save up to 60% dose for wide range of rou-tine applications while maintaining excellent image quality.”

Joseph Schoepf, MD, Department of Radiology, Medical University of South Carolina, Charleston, USA


Topic

2 Pediatric imaging: no breath hold and no anesthesia was necessary for the scan with 0.37s scan-time by using only 1 mSv (Fig. 2A); Split-second thorax scan by using only 1.65 mSv (Fig. 2B and 2C).

mode, approximately half could be scanned at 100 kV. (In general, a tube voltage of 100 kV is suitable for patients with a body mass index of less than 30 or a body weight of less than 90 kg). In these patients, Hausleiter found that the median radiation dose was just 1 mSv. The other half of the patients were scanned at 120 kV, and received a radia-tion dose of 1.6 to 1.8 mSv, still far lower than the typical radiation dose for coro-nary CT angiography. The PROTECTION I study highlights how much progress has been made. In 2007, Hausleiter and an international group of researchers from 50 medical centers set out to determine the typical radiation dose for patients undergoing coronary CT angiography, using CT scanners manufac-tured by a variety of vendors. Published in the February 4, 2009, issue of JAMA, the study showed that the median dose was 12 mSv. “It’s important to realize the large steps we’ve taken,” says Hausleiter. “The dose

we can achieve today is one-tenth of what it was in the PROTECTION I study. That’s a major improvement.” Such a low radiation dose could expand CT’s horizons in the evaluation of heart disease. For example, for patients with high heart rates and irregular heart rhythms, the “step and shoot” Adaptive Cardio Sequence, with prospective ECG-triggering and arrhythmia detection, is ideal and keeps radiation dose to about 2.5 mSv. For patients with reasonably low and stable heart rates, the Flash Spiral is the method of choice. But even for patients with mild arrhythmia, Hausleiter thinks the Flash mode, which captures all necessary data in a single heart beat, may be fast enough to do the job, and at a radiation dose of 1mSv. And, if that one heart beat happens to be an extra unwanted beat generated by the arrhythmia, the Flash’s low radiation dose means there is little risk in repeating the study. A radiation dose of below 1 mSv also

raises the possibility of using CT for screening patients at risk for heart dis-ease. “We need to start thinking about that question,” Hausleiter says. “With coronary CTA, we would gain informa-tion on calcification, the location of plaques, and the presence of noncalci-fied plaques – the type we really worry about. In the end, screening could reduce the number of heart attacks.”

Iterative ReconstructionIterative reconstruction, which Siemens is slated to debut at the 2009 RSNA meet-ing in Chicago, is the latest success story in the company’s mission to reduce radia-tion dose. Essentially, iterative reconstruc-tion introduces a correction loop in the image generation process that cleans up artifacts and noise in low-dose images. Other vendors are working on iterative reconstruction, but Siemens has developed a unique method. A typical approach to iterative reconstruction is to measure data in the reconstructed image

2A

2B

2C


Coverstory

4 Image data reconstruction of an abdominal scan with Standard FBP at full dose (Fig. 4A) and scanned at 60% lower dose while reconstructed with Iterative Reconstruction in Image Space (Fig. 4B). Despite the fact that Fig. 4B was acquired at significantly lower dose it shows the same low noise compared to the standard FBP at full dose.

4A 4B

and compare it to the original data, using differences to identify ways to improve the image. This approach is time-consum-ing because, with each iteration, new measurement data must be calculated. Siemens instead takes the original data and reconstructs a super-high-resolution image. The image is very noisy, because the filtering that ordinarily reduces image noise is not used, in order to avoid any loss of information. Then prior knowledge of the scanned object is used to smooth the image and reduce noise within homo-geneous regions, while contrast edges are preserved. This process is repeated over several steps, or iterations. “Why is Siemens’ approach better? Because we start with a super-high-resolution image and clean it up,” says Thomas Flohr. “We can fine-tune the process, so we don’t lose object informa-tion. We maintain image texture that is familiar to readers, so the resulting image looks like a standard CT image and doesn’t have the plastic-like look that is often the drawback of other iterative reconstruction approaches. And the pro-cess is very fast and efficient.”

3 Image cardio sequence: Fully flexible X-ray pulsing in combination with 75ms temporal resolution results in low dose cardio scan (0.36 mSv dose).

3


6 When fully flexible X-ray pulsing meets 75 ms of temporal resolution, the result is the Flash Cardio Sequence, the most versatile low dose cardio scan on the market. It´s an intelligently triggered sequence that shuts off radiation in the systolic phase when not required and dynamically reacts to irregularities during the ECG-trace. For the first time, a step and shoot mode is robust and fast enough to freeze the heart and visualize the coronary arteries even at high heart rates, thus allowing even low dose cardiac CT without the need for beta-blockers. Additionally the Flash Cardio Sequence introduces the Siemens-only dual-step pulsing, that maintains a low dose level during the systolic phase to calculate ejec-tion fraction in addition to coronary imaging. Therefore, the never before possible combination of low dose coronary imaging and functional information now becomes a reality.

5 Single Source CT requires slow-er table feeds to prevent gaps in the acquired volume (top, center). Dual Source CT combines the data from 2 detectors for faster table feeds above a pitch of 3 (bottom).

Conventional SequenceDose

Dose

Low doseno function

High dosewith function

Low dosewith function

Flash Cardio SequenceDose

necessary dose

inefficient dose

Vol pitch 1

pitch >1

pitch 3.4

Vol

VolTube 1 Tube 2

5

6


Coverstory

Most important, Siemens’ iterative reconstruction technique can reduce radiation dose by up to 60%, depending on the body region and the original scan dose. “With Siemens Iterative Recon-struction I can save up to 60% dose for wide range of routine applications while maintaining excellent image quality” says U. J. Schoepf, MD, Professor of Radiology and Cardiology and Director of CT Research and Development at the Medical University of South Carolina.

Future Directions The next automated tool for dose re-duction is likely to be automatic kV adaptation to the patient’s size and the examination type. Researchers are beginning to understand and further evaluate its effect on image quality and dose. In the PROTECTION II study, for example, Hausleiter and his colleagues randomly assigned 400 patients to undergo coronary CT angio-graphy with either a 100 kV protocol

or the more conventional 120 kV proto-col. Reported at the 2009 American College of Cardiology Annual Scientific Session, the study showed that the use of 100 kV reduced radiation dose by 31%, while image quality scores were virtually identical. “This proves you can use 100 kV very liberally when looking at the coronary arteries,” says Hausleiter. At the Mallinckrodt Institute, Siegel has also been evaluating the radiation savings possible through use of a lower

7 To accelerate the convergence of the reconstruction IRIS applies the raw data re-construction only once. During this newly developed initial raw data reconstruction a so called master image is generated that contains the full amount of raw data in-

7

No one would argue that radiation ex-posure is unimportant in CT. But as dose levels fall, and the risk of induc-ing cancer shrinks, it’s reasonable to take a fresh look at the risk-benefit ratio associated with CT scanning. First, it’s important to know that esti-mates of the long-term risk of devel-oping cancer from radiation exposure are based on studies of atomic bomb survivors. Such studies have a high level of statistical uncertainty at the low radiation doses associated with CT. The most commonly cited estimate of the additional lifetime risk of dying from cancer is 0.05% per 10 mSv of radiation exposure. Not only do many CT scans today deliver far less than 10 mSv, but natural background radia-tion, which is unavoidable, is about 2 to 3 mSv. In addition, the average lifetime risk of dying from cancer in western society is about 25% – which means that after a 10 mSv CT scan, the risk goes up by 0.05% to 25.05%. By comparison, the lifetime risk of dying from heart disease is about 40%. Decisions about whether to eat a healthy diet, quit smoking, and get regular exercise are likely to have a substantial cumulative impact on longevity. Which makes you wonder: Just how safe is it to eat a double cheeseburger?

CT Radiation Dose in Perspective

Fast

Im

ag

e D

ata

Sp

ace

Slo

w R

aw D

ata

Sp

ace

Compare

Dose reduction or image quality improvementWell-established image impressionVery time-consuming reconstruction

Theoretical Iterative Reconstruction

Raw data Raw data reconrecon

Full raw data

projection

Exact image correction


Topic

tube voltage. Her work with Lucite phantoms that simulate the size of various body regions in children has shown that at a tube voltage of 80 kV the radiation dose is reduced when compared to a tube voltage of 140 kV, even when the tube current is increased to ensure good image quality. At the St. Louis Children’s Hospital, Siegel has been using the SOMATOM Definition AS 64-slice CT scanner to scan pediatric patients. She will

continue her research in pediatric phantoms and in patients with this newer generation scanner to determine the impact on radiation dose and image quality of modulating kV. She anticipates that with this newer-generation scanner, the quality of CT studies will improve even further as radiation dose is decreased. “There is an old saying, ‘Beautiful pictures come at the cost of higher radiation dose,’ ” Siegel says.

Medical writer Catherine Carrington holds a master’s degree in journalism from the University of California Berkeley and is based in Vallejo, California.

formation. The following iterative corrections known from true iterative reconstruction are consecutively performed in the image space. In addition, the noise texture of the images is comparable to standard well-established convolution kernels. The new technique results in artifact and noise reduc-tion, increased image sharpness and dose savings up to 60% for a wide range of clinical applications.

“We’ve already disproved that, and we intend to further disprove it.”

Statistical Iterative Reconstruction Iterative Reconstruction in Image Space

Dose reductionFast reconstruction with few parametersUnfamiliar and plastic-like image impression

Dose reduction or image quality improvementWell-established image impressionFast reconstruction in image space

Compare

Fast

Im

ag

e D

ata

Sp

ace

Slo

w R

aw D

ata

Sp

ace

Fast

Im

ag

e D

ata

Sp

ace

Slo

w R

aw D

ata

Sp

ace

Master Master reconrecon

Compare

Image data Image data reconrecon

Exact image correction

Raw data recon

Basic raw data

projection

Basic image correction

1 Mulkens et al.: Use of an Automatic Exposure ControlMechanism for Dose Optimization in Multi-Detector Row CT Examinations: Clinical Evaluation, Medical Physics.


News

Interactive Breath-Hold Control (IBC)System from the Mayo Clinic is now Available Through Siemens

By Stefan Wünsch, PhD, Business Unit CT, Siemens Healthcare, Forchheim, Germany

SOMATOM Emotion FaceliftBy Steven Bell, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The Interactive Breath-Hold Control (IBC)* is a unique Mayo Clinic medical device that allows physicians to more rapidly and accurately diagnose patients, reducing the need for a more invasive surgical biopsy. Monitoring patient respiratory motion using a simple light display, it allows for precise imaging at a consistent reproducible breath-hold level. The IBC device was developed to assist CT interventional procedures, but may also be very useful for PET CT, radiation therapy, ultra-sound, fusion imaging, and other pro-

Siemens’ customer-focused philosophy has always been to continually integrate cutting-edge imaging technology into the daily clinical routine, providing high qual-ity patient care while simultaneously low-ering costs. This continual innovation is focused throughout the Siemens CT product portfolio and has now resulted in the release of the new SOMATOM® Emotion 6- and 16-slice configurations. The new SOMATOM Emotion builds on this platform and features an innovative

cedures or modalities where respiratory motion is an issue. The device does not physically interface with imaging equip-ment and is therefore fully portable. The wireless display includes a simple belt with expandable bellows to be wrapped around a patient’s upper abdomen or lower chest and connected to the IBC system. Individual light displays are located next to the patient, the radiolo-gist’s image monitor and the CT opera-tor console. All displays have a wireless connection to the system control, which sits next to the patient on the CT table.

Key Characteristics

■ Increased patient care and comfort■ Increased safety■ Potential decrease in healthcare ex-

penses for patients, by avoiding the necessity for more invasive and costly surgical biopsy procedures

■ Decrease in needle placement and procedure time■ Decrease in complications■ Increase in accuracy

*This device will be distributed by Medspira (USA).

Interactive Breath-Hold Control System from Mayo Clinic was developed to assist CT interventional procedures.

The newly designed SOMATOM Emotion dem-onstrates Siemens’ commitment to continually bringing new technology to all segments of the CT market.

* *based on system sales.

new product design and new software features. It showcases Siemens’ commit-ment to offering not only remarkable image quality, but also bringing leading workflow features, and reducing the on-going costs of CT service.The new SOMATOM Emotion 6- and 16- slice configurations continue to offer the smallest tube focal spot and the highest number of effective detector channels in the mid-range CT market, both of which underpin the excellence in image detail.The new software developments that have been brought to the SOMATOM Emotion platform have a significant focus on CT workflow. A key feature now available on the SOMATOM Emotion 6- and 16-slice configurations is syngo Expert-i which enables remote access to the scan console from any remote com-puter with access to the hospital or prac-tice network. This feature alone has the ability to significantly improve workflow in any practice because medical staff are

no longer required to physically attend the CT suite to assess images or decide on appropriate scan protocols.The newly designed SOMATOM Emotion also builds on the Total Cost of Owner-ship advantages for which the SOMATOM Emotion is known. With lower power requirements, reduced heat output and significantly smaller installation space, the SOMATOM Emotion is a cost effec-tive profit center for many customers worldwide.With over 6,700 systems installed SOMATOM Emotion remains the most popular CT system in the world** through continually bringing new clinical, workflow and cost innovations to Siemens’ CT customers.

Somatom_Inhalt_CC.indd Abs2:16Somatom_Inhalt_CC.indd Abs2:16 13.11.2009 12:11:37 Uhr13.11.2009 12:11:37 Uhr


News

International CT Image Contest – Highest Image Quality at Lowest Radiation DoseBy Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

For years physicians have been educated to follow the ALARA (As Low As Reason-ably Achievable) principle. That is, to use the minimum amount of dose required to obtain the necessary images. Siemens sees its responsibility to provide physi-cians with the solutions that enables them to further lower radiation dose without having to compromise on image quality. Siemens wants to encourage physicians from all over the world to utilize their SOMATOM® Definition CTs to the fullest extent and to share their excellent imag-es obtained with the lowest possible radiation dose. Participants can share their work with the world by joining the Siemens International CT Image Contest.

The JuryA highly prominent jury consisting of pioneers in the field of CT will be judging the images. Professor Stephan Achenbach, MD – Uni-versity of Erlangen, Professor Dominik

The Siemens International CT Image Contest is Siemens’ first contest where physicians and technologists from around the world send in their work to compete for the best image quality at the lowest possible radiation dose.

Fleischmann, MD – Stanford University Medical Center, Professor Elliot K. Fishman, MD – Johns Hopkins Hospital, Professor Yutaka Imai, MD – Tokai Uni-versity School of Medicine, Professor Zengyu Jin, MD – Beijing Medical Union College, Professor Borut Marincek, MD – University Hospital Zurich, Professor Maximilian Reiser, MD – Ludwig-Maxi-milians-University Munich, Professor Uwe Joseph Schoepf, MD – Medical University of South Carolina.

Prizes and Awards There will be six categories for image submission, and, accordingly, six winners in total. Winning images will be exhibited at the ECR 2010 in Vienna, Austria, as well as at RSNA 2010 Chicago, USA. Win-ners will receive the official image gallery book that concludes the International CT Contest. Along with the image, the participant’s name and institution will be honored. Furthermore, the winner will receive an honors certificate, a large print

www.siemens.com/image-contest

out of their own winning image, a Canon EOS 50D camera*, and the opportunity to be honored in several different media (e.g. SOMATOM Sessions).

ParticipationImages can be submitted online by users of the SOMATOM Definition AS, SOMATOM Definition, and SOMATOM Definition Flash.

TimelineClosing date for image submission is February 1st, 2010. Please visit our web-site for more details on how to enter and compete for one of the most prestigious awards in the international community today.

* The winners will receive the opportunity to person-ally present their images. Each presentation will be covered by a written contractual fee in the amount of 1000 Euro.


Topic

New Software Versions for the SOMATOM Defi nition FamilyBy Rami Kusama, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The new software version for the SOMATOM® Definition and SOMATOM Definition Flash, syngo CT 2010A, will be introduced in the first quarter 2010, syngo CT 2010B for the SOMATOM Definition AS in the second quarter 2010.

syngo CT 2010A and syngo CT 2010B will offer:■ IRIS* (Iterative Reconstruction in Image Space) is a method which uses multiple iteration steps for the reconstruction of CT data with every step further reducing image noise and thus allowing lower ra-diation dose. IRIS starts by reconstructing a complex master image, and then itera-tively improves image quality to achieve superior, natural looking images.■ syngo Remote Assist takes clinical ap-plications support and training to a new dimension. This on-demand, remote ser-vice puts real-time troubleshooting and support, as well as virtual education at the users fingertips. Its seamless and si-multaneous virtual interaction will help to enhance image quality and equipment optimization. syngo Remote Assist is easy to implement and use, and requires no

modification to customer’s system or IT-network.■ CARE Contrast: This unique CARE solu-tion is based on the international stan-dard for the communication between CT scanner and injector. It synchronizes CT scan and contrast media injection, allow-ing for efficient and confident monitor-ing of patients during contrast media in-jection and scan start, even if only one technician is present. In addition, the in-jection parameters are then transferred from the injector to the patient protocol. Due to its open interface technology, it is ready for future applications.■ Neuro BestContrast: The challenge in neuro imaging is to achieve better con-trast without an increase in noise. Neuro BestContrast supports this by intelligent-ly improving gray white matter differenti-ation on a routine basis. ■ 4D Noise Reduction: Already success-fully introduced on the SOMATOM Definition Flash, 4D Noise Reduction significantly improves image quality and reduces radiation dose by up to 50% for perfusion examinations.

syngo CT 2010A will offer:■ X-CARE: Previous attempts at dose re-duction were very successful but did not specifically take into consideration highly dose-sensitive areas such as the thyroid gland, eye lens or women’s breasts. X-CARE enables organ-sensitive dose protection by reducing sensitive-area exposure up to 40% without loss of image quality. ■ Hi-Pitch Spiral: Even the most advan-ced single source CTs are limited in their scan speed by the maximum table feed that can be used and still allow the acquisition of contiguous data. Dual Source technology, combining the data from two detectors, in combination with the Hi-Pitch Spiral, offers maximum pitch of 3.0 and therefore high scan speed.

syngo CT 2010B will offer:■ ASB (Adaptive Signal Boost): This new feature improves the signal to noise ratio by selectively optimizing lower sig-nals, for example, when obese protocols are used.

For the SOMATOM Definition AS, (Fig. 1), SOMATOM Definition Flash (Fig. 2) and the SOMATOM Definition the new software versions syngo CT 2010A and syngo CT 2010B will be available.

21

*Optional, needs to be purchased separately.


News

Coronary CTA in Flash Spiral mode at a dose of 0.7 mSv.

Flash Cardio Dose Saving Capabilities Inspire Researchers to Launch PROTECTION IV TrialBy Peter Aulbach, Business Unit CT, Siemens Healthcare, Forchheim, Germany

Coronary CT angiography with SOMATOM® CT Scanners provides stable image quality and, due to its ability to detect coronary artery stenoses with a high negative predictive value (99.7%1), its use is meanwhile considered “appro-priate.” The method’s major advantage lies in the fact that adequate image quality is provided, so that coronary artery stenoses can be safely ruled out. Coronary CT angiography can be used to avoid invasive angiography in patients who are symptomatic, but do not have high pre-test likelihood for actually hav-ing hemodynamically significant lesions. Such patients are often of young age, and female patients are often among those who present with atypical symptoms. So radiation exposure associated with coro-nary CT angiography is of particular con-cern in this group. The latest SOMATOM Definition Flash, with 75 ms temporal resolution, even exceeds the ability to perform ECG-trig-gered spiral data acquisition by using very high pitch values of up to 3.4 in its Flash Cardio mode, leading to unprece-dented scan speed of up to 45 cm/s. The high pitch and fast table speed of the Flash Cardio mode allow performing im-age acquisition for the entire heart with-in a single cardiac cycle. Radiation expo-sure is kept low since no slice overlap is needed which allows a dose of 1 mSv and below for coronary CT angiography. In clinical trials like the international “Prospective Randomized Trial on Radia-tion Dose Estimates of CT Angiography in Patients” (PROTECTION I) the dose for car-diac CT of five CT units from four differ-ent manufacturers were compared. The basis of the study was 1,965 cardiac CT scans that were carried out in a total of 50 clinics and heart centers. The study showed clear differences in radiation doses depending upon both the CT sys-tem manufacturer and the behavior of

www.siemens.com/ct-cardiologywww.siemens.com/SOMATOM-Definition-Flash

the operator. The dose values for cardiac CT angiography reached up to 30 mSv 2. The study especially emphasizes that radiation can be significantly reduced by more consistently using already existing technologies for dose reduction in CT systems.The subsequent PROTECTION II trial eval-uated the impact of 100 kV scan protocol for coronary CT angiography on diagnos-tic image quality and radiation dose. The data showed that with the 100 kV setting dose could be lowered by 50%, compared to the 120 kV protocol, while at the same time preserving the high image quality. The ongoing PROTECTION III trial evalu-ates the dose savings which can be achieved with sequential scanning mode. The new SOMATOM Definition Flash with its sub-mSv cardiac capabilities through Flash Cardio inspired the re-searchers from Munich to initiate the PROTECTION IV study, which is currently ongoing as well. Preliminary studies

already demonstrated the feasibility of this new and promising scan technology. Institutions already using the SOMATOM Definition Flash in daily clinical practice scan more than 70% of their patients using the Flash Cardio protocol. The re-searchers want to proof that the image quality is being maintained with the reduced radiation dose of this new scan technique when compared with established conventional scanning techniques. First results are expected towards the end of 2009.

1, Coronary CT angiography predicts outcome in inter-mediate pre-test probability individuals: A prospective study on 1157 patients, G M. Feuchtner et al. Dept. Radiology II and Cardiology; Innsbruck Medical Uni-versity, Moderated Poster, ESC, Barcelona, 08/2009.

2, Estimated Radiation Dose Associated With Cardiac CT Angiography, J. Hausleiter et al. JAMA, February 4, 2009 – Vol 301, No. 5.


News

RSNA 2009 – Arena for SOMATOM Defi nition Flash Publications

Scientifi c PapersDual Source Spiral CT at Pitch Values up to 3.2: Assessment of Image QualityS. Leng, PhD, Rochester, MN; L. Yu, PhD; C. Eusemann, PhD; B. Schmidt, PhD; T. G. Flohr, PhD; C. H. Mccollough, PhD

Sedation-free Pediatric CT: Use of a High Pitch DSCT Scan Mode with 75 ms Temporal Resolution to Obtain Artifact-free Images of a Rapidly Moving ChildT. Allmendinger; C. Eusemann, PhD; B. Schmidt, PhD; T. G. Flohr, PhD; C. H. McCollough, PhD, Rochester, MN

Improving the Differentiation of Uric Acid Stones Using Dual Energy Computed To-mography Flash TechnologyP. Stolzmann, MD, Zurich ; H. Scheffel, MD, PhD; S. Leschka, MD; L. M. Desbi-olles, MD; K. Rentsch, MD; H. Alkadhi, MD; et al.

Performance of Different Dual Energy CT (DECT) Protocols Using the Definition Flash System for the Discrimination of Re-nal Cysts and Enhancing MassesS. Leschka, MD, Zurich, CHE; P. Stolz-mann, MD; H. Scheffel, MD, PhD; S. Bau-mueller; B. Marincek, MD; H. Alkadhi, MD; et al.

Assessment of an Image-based Method to Calculate Monoenergetic Images from Dual Energy (DE) Image DataB. Krauss, PhD; B. Schmidt, PhD; M. U. Sedlmair, MS; T. G. Flohr, PhD

Quantitative Whole Heart Stress Perfusion CT Imaging as Noninvasive Assessment of Hemodynamics in Coronary Artery Steno-sis: Preliminary Animal ExperienceA. H. Mahnken, MD, Aachen, GER; H. Pi-etsch, PhD; B. Schmidt, PhD; T. Allmend-inger; U. Haberland; E. Klotz, PhD; et al.

Assessment of Image Quality of Different Image Reconstruction Approaches for the Evaluation of Myocardial Perfusion De-fectsT. Allmendinger; R. Raupach, PhD; B. Schmidt, PhD; E. Klotz, PhD; H. Pietsch, PhD; T. G. Flohr, PhD

Use of a Pitch Value of 3.2 in Dual Source Cardiac CT Angiography: Dose Perfor-mance Relative to Existing Scan ModesC. H. McCollough, PhD, Rochester, MN; S. Leng, PhD; B. Schmidt, PhD; T. All-mendinger; C. Eusemann, PhD; T. G. Flohr, PhD Comparison of Temporal Resolution in Dual Source (DS) Images and Dual Energy (DE) Images Based on Cardiac Motion Phantom Data R. Raupach, PhD; T. Allmendinger; B. Schmidt, PhD; B. Krauss, PhD; T. G. Flohr, PhD

2nd Generation Abdominal Dual Energy CT with Tin Filtering: Assessment of Image Quality and Radiation ExposureA. Graser, MD, Munich, GER; T. R. John-son, MD; W. H. Sommer, MD; M. F. Reiser, MD; C. R. Becker, MD; K. Nikolaou, MD

Dual Energy CT – How about the Dose?T. R. Johnson, MD; J. C. Schenzle; W. H. Sommer, MD; G. Michalski; K. Neumaier; C. R. Becker, MD; et al.

Pulmonary Perfusion Imaging with Dual Energy CT – Image Quality and DoseT. R. Johnson, MD; W. H. Sommer, MD; J. C. Schenzle; G. Michalski; K. Neumaier; C. R. Becker, MD; et al.

Sub-second ECG-synchronized Chest CT using Dual Spiral AcquisitionW. H. Sommer, MD; J. C. Schenzle; C. R. Becker, MD; K. Nikolaou, MD; M. F. Reiser, MD; T. R. Johnson, MD

Education Exhibits

128-slice Dual Source CT: How Does it Work and What Can it Do?

These and many more results, sessions, discussions, education exhibits and sym-posia about SOMATOM® Definition Flash and its novel low dose CT scanning can be found on the RSNA 2009.

Just published: Diagnostic accuracy of high-pitch Dual Source CT for the assessment of coronary stenoses: first experience. H. Alkadhi et al. Eur Radiol, Sept 2009, Epub ahead of print

Prospectively ECG-triggered high-pitch spiral

acquisition of coronary CT angiography using Dual Source CT: technique and initial experi-ance. S. Achenbach et al. Eur Radiol, Sept 2009, Epub ahead of print

www.rsna.org

With the introduction of the new CT scanner SOMATOM Defi nition Flash during RSNA 2008, Siemens set new standards regarding speed and dose reduction. One year later, the great number of publications submitted and accepted for RSNA exceeds all expectations. Experience shows that promise becomes reality.


News

1 4D Noise Reduction in CT perfusion imaging allows to reduce slice thickness with improved image quality. (e.g 10mm p 5mm), (Fig. 1A).

Dual Energy (DE) VRT image of the right foot (sagittal tendons image) visualizing multiple ten-dons around the joints (Fig. 1B), courtesy of Shandong Medical Imag-ing Research Institute, Shandong, P.R. China. DE image shows Xenon concentration in the lung (Fig. 1C), courtesy of University Munich, Campus Großhadern, Germany.

syngo 2009A – a New Era for Routine and Advanced Diagnostic ImagingBy Stefan Wünsch, PhD and Daniel J. Ruzicka, MD, MSc, Business Unit CT, Siemens Healthcare, Forchheim, Germany

With syngo 2009A, the latest software version for the MultiModality Workplace (MMWP), a whole set of new functional-ities has been introduced as well as numerous improvements to existing applications. An important growth area for clinical applications is the functional evaluation of whole organs. In the field of neuro-im-aging, the new syngo Volume Perfusion CT (VPCT) Neuro provides 3D analyses of volumetric datasets of the brain. In com-bination with Adaptive 4D Spiral of the SOMATOM® Definition AS+ or SOMATOM Definition Flash, the entire brain can be examined. Applying a newly developed, elaborate technique implanted with syngo 2009A on MMWP in the syngo Volume Perfusion software, noise reduc-tion of dynamically acquired data is pos-sible (Fig. 1A). Thus, the radiation dose of dynamic CT perfusion exams can be reduced by up to 50%, while retaining equivalent diagnostic information. Furthermore, it will allow using a higher pitch for perfusion scans, which gives

the capability to enlarge the scan-range. Also, thinner slices providing more de-tailed information about the perfusion are now possible. Following the 3D evaluation concept of CT data, the current syngo VPCT Body evaluates dynamic 3D perfusion CT data of the body, e.g. for lung and liver tumors. Having updated the current algorithm and implemented 4D Noise Reduction as well, whole organ perfusion can be performed on fewer time-points, which significantly reduces the necessary dose in these examinations. Deconvolution-based perfusion maps like BloodFlow, BloodVolume, MeanTransitTime are now available in syngo VPCT Body as well. By further improving Dual Energy applica-tions, syngo 2009 provides important additional value for Dual Energy CT (DECT) users. For SOMATOM Definition Flash users, for example, Dual Energy with Selec-tive Photon Shield opens the door to a new world of characterization, visualizing the chemical composition of material. Within the syngo 2009 application,

syngo DE Musculoskeletal uses this infor-mation to display tendons and ligaments in a CT image (Fig. 1B), providing addi-tional information without additional scans for faster diagnosis, especially in emergency situations. With the syngo DE Xenon application available for the SOMATOM Definition Flash, the Xenon concentration in the lung can be visual-ized without use of an additional non-contrast scan. The new application syngo DE Lung Nodule uses Dual Energy information to visualize the contrast agent concen-tration in lung nodules without use of an additional non-contrast scan. With a special focus on supporting the routine workflow Siemens further en-hanced InSpace4D including: Auto Table Removal, parallel and radial range on all image types, PET/SPECT images loadable, fusion functionality, opacity slider for re-moved bones (BR) and InSpace AVA (centerline, ranges for CPR and cross sections and improved reporting).

10 mm

5 mm

No

4D

No

ise

Re

du

ctio

n

1A

Wit

h 4

D N

ois

e R

ed

uct

ion

1B

1C


News

Leading Technology in Rural Hospital By Karen Schweizer*, Jakub Mochon* and Steven Bell**

* Computed Tomography Division, Siemens Medical Solutions, Malvern, USA

** Business Unit CT, Siemens Healthcare, Forchheim, Germany

Situated in northern Box Elder County in Utah, Intermountain Bear River Valley Hospital serves about 18,000 people. Box Elder County is primarily a farming community, and it is not uncommon for some of its people to simply forgo medi-cal care if getting it means they have to travel a significant distance. All the more reason why executives from this 16-bed hospital felt it was important to upgrade their single-slice CT scanner. With the single-slice scanner, Bear River was unable to perform arterial studies, which represented an increasing need of its patient population. “We were sending all of these studies out,” says Bret Rohde, radiology manager at Bear River. “In fact, that was one of the biggest ben-efits of upgrading. We were able to stop transferring patients who needed these studies from our Emergency Department (ED) to other hospitals.” Bear River is part of Intermountain Healthcare, a nonprofit system of hospi-tals, surgery centers, and clinics that serves Utah and southeastern Idaho. In-termountain Healthcare narrowed down Bear River’s CT choice to three vendors. After an extensive review, Bear River se-lected the SOMATOM® Emotion® 16. Al-

though there were many benefits to selecting the Emotion, the biggest fac-tors were real-time scanning, Siemens’ commitment to reducing CT dose, and the simplification of this process from the user’s perspective.

Superior Real-Time Scanning & Dose Modulation“The main thing that attracted me toward the Emotion was its real-time scanning capabilities,” says Rohde. “As far as I’m concerned, real-time scanning is essen-tial. If we’re scanning a patient and he moves, we can correct it. And, we’ll often open our field of view a little bit further than we need, which enables us to ac-quire all the information we need. There-fore, we’re not repeating exams, our effi-ciency is better, and we’re not giving patients more dose than necessary.” The SOMATOM Emotion uses an Ultra Fast Ceramic detector, which requires the smallest amount of dose to deliver exceptional image quality. In addition, since every patient is unique in terms of size, weight, and anatomy, the Emotion’s fully automated dose man-agement system, CARE Dose4D™, can tailor dose to a specific patient’s need.

It is embedded right into the Emotion system for seamless dose modulation while still providing the radiologist read-ing the study with a high-quality image. “We don’t have to worry about dose modulation any longer,” says Rohde. “CARE Dose4D runs automatically. We don’t even consider shutting it off. Our technologist can just go in, pick a proce-dure, get the examination done, and the patient receives the least amount of ra-diation possible.” The dose advantages of the SOMATOM Emotion is one reason behind the great success of over 6,700 installed systems.

Simplifi ed StudiesThe SOMATOM Emotion offers a full range of advanced clinical applications, many of which are helping Bear River at-tend to its patients quickly, efficiently, and effectively. “Not only are we able to do arterial studies but we’ve also had a huge increase in PE (pulmonary embo-lism) chest studies. Our old scanner just did not provide the information we need-ed for these, so we had to send them out. But now, we’re bringing almost every-thing back in-house,” says Rohde. “Take IVPs (intravenous pyelograms) for exam-

One of the biggest fac-tors for selecting the

SOMATOM Emotion was Siemens’ commitment to

reducing CT dose and the simplification of this

process from the users perspective.


News

CARE Dose4D™This means true, real-time modulation, dose calculations made from a single topogram and real-time feedback from detectors to the X-ray tube to continual-ly monitor and adjust the exposure.

Exportable Dose Report for All Patients Implemented on the new SOMATOM Emotion, this report is a comprehensive summary of the patient’s exposure and is fully DICOM compliant and exportable to a PACS system automatically.

Real-time ImagingImplemented for both the topogram and spiral acquisition, this feature can save unnecessary dose by allowing the user to stop the scan early if required anato-my is covered or if movement has ren-dered the scan non-diagnostic.

Ultra-fast Ceramic DetectorThe SOMATOM Emotion uses exactly the same high-end detector material as implemented in the industry-leading SOMATOM Definition™ Flash. The detec-tor’s efficiency is key to Siemens dose reduction leadership.

Hand CARE for InterventionThe exposure can be turned off for a section of each tube rotation, signifi-cantly reducing dose to staff during interventional procedures.

CT dose reduction on the SOMATOM Emotion:

ple. We used to perform a lot of these but now we can handle them with CT uro-grams, which are noninvasive and easier for the patient and our staff.” Similarly, confidence in Bear River’s ED studies has increased. Prior to the instal-lation of the SOMATOM Emotion 16, Rohde and his staff had to perform mul-tiple scans for the chest, abdomen, and pelvis. Now, the SOMATOM Emotion can handle traumagrams, covering all areas at once and with one injection – again, further reducing dose. “I was surprised how quickly the physicians bought into the system and how fast they started us-ing it,” says Rohde. “Our volumes went up even quicker than I expected.” “We more than doubled our volumes al-most immediately after installation,” says Eric Packer, the hospital’s CEO and administrator. “And, it’s been a constant growth since then. Therefore, members of our community no longer have to travel extensively for access to these ser-vices at larger facilities. We brought ad-vanced technology closer to home.”Bear River’s radiology group reads its scans remotely 24/7, providing reports within 20 minutes of the scan. If the study was ordered through the ED, the ra-diologist will call the ED physician with the results. This ability to share top quali-ty images quickly helps speed this process and instills additional clinical confidence. “One of the radiologists from our group told me that they are confident that any images they receive from a Siemens product will be of the highest quality. It

makes their job so much easier when they receive a high-quality image, and they can dictate their findings with confi-dence,” says Rohde. “That’s saying a lot.”

Importance of Technology in a Rural SettingAccess to this kind of state-of-the-art technology can make all the difference to a rural hospital like Bear River. “I think technology is as important – or more im-portant – for a small hospital like ours,” says Rohde. “Because we’re remote and we don’t have in-house radiologists to support us, the proper technology makes it a lot easier to communicate with them and enable us to provide services similar to a large hospital.” Packer agrees.” Technology like this CT scanner lets people know that when they come here, their care is equal to what they might get at a larger, tertiary facility.”

Impeccable ServiceState-of-the-art technology is one of the cornerstones of Bear River’s new 44,000-sq.-ft. facility, which opened in February 2009. The SOMATOM Emotion’s sleek, modern look lends itself well to this high-tech facility and has ad-ditionally helped bolster the image and reputation of the hospital. “People are really impressed when they see it,” says Packer. “They can see that it is a modern piece of equipment, which adds to our facility’s overall high-tech feel.”

Bret Rohde, Radiology Manager, RT, RPA, Bear River Valley Hospital, Tremonton, UT.

Eric Packer, CEO and Administrator, Bear River Valley Hospital, Tremonton, UT.

Installation, which occurred twice (once at the old facility and again at the new location), went very smoothly. “The scanner was in our previous location for one year before it was relocated to our new facility,” says Rohde. “The transition was fairly seamless and the installation crew was awesome.”“The Siemens product, with its German engineering, is very high quality and the service has been impeccable,” Rohde continues. “I would recommend them to everyone.”


Business

Lowest Dose Motivates PurchaseYoung patients present several special challenges when it comes to diagnostic imaging. Without doubt, one of the most critical is keeping radiation exposure at a minimum. The industry’s lowest dose and fastest scan speed make the SOMATOM Defi nition Flash ideal for pediatric applications.

By Sameh Fahmy

Arnold Palmer Hospital for Children, Or-lando, Florida, prides itself on providing advanced, specialized care for children. It is no surprise that when the 158-bed pe-diatric hospital decided to purchase a new CT scanner, it chose the one that de-livers the fastest speed and the lowest dose of any CT on the market. Siemens’ SOMATOM® Definition Flash combines Dual Source technology with the fastest available hardware components and in-novative features, enabling thoracic scan-ning without breath holds and, in many cases, producing high-quality images with doses of less than one milliSievert (mSv).“It is certainly going to give patients and their families a higher level of comfort about CT,” says John Bozard, President

of Arnold Palmer Medical Center, which includes the children’s hospital and the adjacent 285-bed, Winnie Palmer Hospi-tal for Women and Babies. “I can’t think of a better way to explain quality than by saying, ‘this technology is the best there is – there is nothing out there that com-pares.”

Small Dose for Small PatientsArnold Palmer Hospital was founded 20 years ago as Central Florida’s first hospi-tal exclusively for children. It has grown steadily with the region’s population, and last year alone performed nearly 11,000 CT exams using two scanners: a Siemens Sensation 64-slice and an aging Siemens SOMATOM +4. The growing patient load and the need to replace the aging, 4-slice

CT scanner put the hospital in the market for a new scanner, and the low dose that the SOMATOM Definition Flash offers made an ideal choice for the hospital, says Joseph Foss, MD, Chair of Pediatric Radiology. “Because we are a pediatric hospital, minimal dose for diagnostic imaging was a key factor,” Foss says. “We reviewed all of the systems available, and the Definition Flash definitely provided the lowest dose possible for our patients, which is very important for us.”He goes on to explain that, while reduc-ing radiation exposure is important for all patients, pediatric patients in particular are thought to be more vulnerable to the adverse effects of ionizing radiation. He adds that many pediatric patients, such as those with cancer, must undergo re-peated scans over an extended period, making the need to reduce radiation ex-posure even more critical. Foss was im-pressed by the depth at which Siemens considered all of the means possible to reduce dose. Exposure time is minimized in the so called Flash Spiral mode be-cause the two X-ray sources and detec-tors of the SOMATOM Definition Flash simultaneously acquire data to allow for pitch values of up to 3.4 and an unprece-dented scan speed of 45 cm/s. That en-ables a routine acquisition of the entire heart in a quarter of a second with less

“I can’t think of a better way to explain quality than by saying,

‘this technology is the best there is – there is nothing out there that compares.”

John Bozard, President, Arnold Palmer Medical Center, Orlando, Florida, USA


TopicBusiness

parents to watch their child being sedat-ed and even more difficult to watch as a child emerges from sedation, confused and unsure of what just occurred. In addition to benefiting patients by re-ducing dose, Foss says the rapid speed of the SOMATOM Definition Flash can im-prove diagnostic capability by allowing him and his colleagues to obtain images free of motion artifacts that can make scans difficult to interpret. He adds that the ability to clearly image small vessels in the periphery of the lungs will espe-cially benefit the hospital’s growing Con-genital Heart Institute. The Dual Energy nature of the imaging can also benefit patients by significantly reducing the rate and volume of intravenous contrast bolus required, Foss says. Bozard notes that, al-though his hospital did not purchase its new CT scanner as a differentiator for the purposes of marketing or expanding its referral base, being the world’s first pedi-atric hospital to install the SOMATOM Definition Flash is tangible evidence of its focus on the health of children. “We are committed to having the highest quality level available,” Bozard says. “And that mandates us to stay on the cutting edge of everything medical, whether it is ideas for new services, new ideas about build-ings and building structures, or new ideas about equipment.”

than 1 mSv of radiation dose. Dual Ener-gy is as dose efficient as a single 120 kV scan, because the Selective Photon Shield blocks unnecessary photons of the X-ray energy spectrum. X-CARE automatically switches off the X-ray tube during por-tions of the rotation that would expose sensitive areas, such as the eye lens or thyroid gland. And Siemens’ unique Adaptive Dose Shield automatically moves shields into place to block unnec-essary pre- and post-spiral dose. “Putting all of these together in one scanner is the most comprehensive system for dose re-duction on the market-period,” Foss says. “And it persuaded us without any ques-tion that this was the system for us.”

Flash Speed Eliminates Breath HoldsThe requirement for breath holding during CT scans has always been a chal-lenge with pediatric patients and often resulted in the need for sedation. But Bozard notes that the speed of the SOMATOM Definition Flash can eliminate the need for a breath hold and therefore result in a scan that is less burdensome and safer for patients. “When you have to sedate a child for any type of procedure, whether it’s a surgical procedure or a test, there are always risks involved,” Bozard says, adding that it is difficult for

Sameh Fahmy, MS, is an award-winning freelance medical and technology journalist based in Athens, Georgia, USA.

The Arnold Palmer Medical Center is composed of Arnold Palmer Hospital for Children (left) and Winnie Palmer Hospital for Women & Babies (right).

“Because we are a pedi-atric hospital, minimal dose for diagnostic imaging is a key factor. The low dose that the SOMATOM Defi nition Flash offers made it an ideal choice for the hospital.”

Joseph Foss, MD, Chairman, Pediatric Radiol-ogy, Arnold Palmer Medical Center, Orlando, Florida, USA


Business

RIPIT to the Rescue: A New Protocol for Trauma ImagingSavvas Nicolaou, MD, Director of General and Emergency Trauma Radiology at Vancouver General Hospital in British Columbia, is challenging today’s standard of care in the emergency department. Nicolaou and his team have developed an innovative process called the Rapid Imaging Protocol In Trauma (RIPIT) that uses Dual Source CT scanning to quickly diagnose patients and save lives.

By Amy K. Erickson

In June 2009, Savvas Nicolaou, MD, from Vancouver General Hospital gave a presentation at the SOMATOM World Summit in Valencia, Spain, where he dis-cussed the impact of routine whole-body

imaging in a trauma setting and high-lighted the many benefits of RIPIT. This article is a report on that presentation.Savvas Nicolaou begins his presentation by explaining why imaging critically in-

jured patients is essential for accurate treatment. “Understanding the full spec-trum of injuries leads to better decision-making and pre-operative planning,” he says. Nicolaou notes that clinical find-

1 Axial image from the base of the scull, looking along the left temporal lobe. The scan was done with Neuro Perfused Blood Volume (PBV) mode on the RIPIT protocol: an abnormality could be seen on the PBV image (Fig. 1A), while the non contrast image (Fig. 1B) was normal, not showing any aberrance.

1A 1B


patients and is implemented before the primary survey. “We scan directly from the emergency department, right on the trauma table. It is a very fast imaging process, and the time saved in the acute traumatic setting is a critical benefit to patient outcomes,” says Nicolaou. “We believe it is faster and more accurate in identifying airway injuries and circulatory abnormalities.”Video clips of poly-trauma patients imaged from brain to pelvis were shown throughout the presentation. One patient had fallen 20 feet. The scan identifies a vascular injury to the liver, as well as kidney trauma and a bowel perforation. “The bowel perforation would have been very difficult for the surgeon to identify if he didn’t know the initial interpretation of the CT examina-tion,” explains Nicolaou. RIPIT is also useful prior to treating penetrating ob-ject (Fig.2) and gunshot injuries because the scan clearly depicts the trajectory and reveals any damage to vascular structures or bony anatomy, he says.

A Clear Benefi tVancouver General Hospital is a level one trauma center with approximately 6,000 trauma-related cases each year, including 1,000 severe poly-trauma patients. Nicolaou presents the results of a retrospective analysis conducted at Vancouver General Hospital on the effectiveness of RIPIT, based on three outcome measures: scanning time, radi-ation dose and image quality. After ana-lyzing the data from about 100 patients, Nicolaou says he identified a 36% reduc-

ings can be misleading in 20% - 50% of blunt poly-trauma patients. In cases where there is a loss of consciousness or a head injury, a physical examination is only 16% reliable in detecting abdomi-nal injuries. Additionally, adds Nicolaou, imaging decreases the mortality in poly-trauma patients. “We believe that death begins in the trauma bay, and we strong-ly believe it can often be stopped with the Dual Source CT scanner in the emer-gency department,” he says.Nicolaou refers to a recent study pub-lished in the journal Lancet that investi-gates the benefits of routine whole-body imaging in a trauma environment. The retrospective, multicenter study demon-strates that when compared to a tradi-tional imaging approach, a whole-body CT protocol, when instituted early, has been shown to improve mortality and morbidity by reducing the number of missed diagnoses by up to 28%, reduc-ing the time to definitive diagnosis, and correctly managing the course of treat-ment. The protocol is based on 0.5 s ro-tation and a pitch of 1.0. The contrast medium is applied as follows: 4cc/s total of 120cc followed by 50/50 cc mixed saline chaser. The initial arterial phase is followed by a portal phase without a delay phase. The initial read is done by 3mm axial scans of the whole body in arterial and portal venous phase.

RIPIT Protocols for Trauma PatientsTwo types of rapid imaging protocols have been developed for emergency sit-uations. The first protocol is for semi-unstable patients and is used as part of the primary survey, a typical routine where physicians identify life-threaten-ing conditions. “According to standard-ized trauma guidelines, the primary survey is usually Airway, Breathing, Cir-culation (ABC),” explains Nicolaou. “However, we believe that after Airway and Breathing, C stands for CT, not Cir-culation. We strongly believe that CT can identify the source of bleeding better than clinical parameters. We know for a fact that clinical parameters are not able to predict which patients are in shock.”The second protocol is for unstable

tion in scanning time and a dose reduc-tion of approximately 23% when using RIPIT versus not using RIPIT. However, there was a slight decline in image quali-ty with the RIPIT. “Overall, we saw a de-crease in time and a decrease in radia-tion dose at the expense of a slightly elevated image noise with the RIPIT pro-tocol,” says Nicolaou. Although the num-bers indicate a clear benefit to using RIP-IT, he notes that additional analysis needs to be done using a larger study population.Nicolaou believes that the integration of rapid whole-body imaging into early trauma care can provide more accurate diagnoses and significantly increase patient survival. “Future directions in-clude the development of computer-aided detection devices that will allow for rapid ease of interpretation of critical findings,” he says, concluding, “The devel-opment of the RIPIT protocol means that no person is left behind. It is true full-body imaging.”

Amy K. Erickson is a health and medical jour-nalist based in Chicago, Illinois, USA. Her work has been published in numerous magazines, including CURE and Nature Medicine.

2 VRT of a penetrating trauma, scanned with the RIPIT protocol: a dagger penetrated through the posterior aspect of the body. The surgeon need-ed to know the trajectory before removing the object, to see whether it damaged any vascular structures – which turned out not to be the case, in this patient.

Savvas Nicolaou, MD, Vancouver General Hospital, University of British Columbia, Vancouver, Cana-da, speaking at the SOMATOM World Summit in Valencia, Spain.

2


Business

Payback Time: How New CTs Justify the InvestmentUpgrading to next generation Computed Tomography (CT) systems benefi ts the bottom line, thanks to lower radiation and higher resolution.

By Eric Johnson

As the Americans say, “It takes money to make money.” And judging from the experience of the University Hospital Zurich, this really is the case. Almost two years ago, the hospital’s Institute of Diagnostic Radiology took on board two unique scanners from the high-end of Siemens’ range: a Dual Source SOMATOM® Definition and a SOMATOM Definition AS. In a curtain-raising look at these new scanners (see pages 20–21 of SOMATOM Sessions, November 2008 at www.siemens.com/healthcare-maga-zine), the institute’s head of radiology, Professor Borut Marincek, MD, justified the outlay on the basis of reduced dos-

age. “For the sake of our patients,” he said, “we will always opt for the latest technology that offers the best results with the lowest possible dosage.” So SOMATOM Sessions recently went back to the Institute to ask the hanging ques-tion: Was the investment worth it?“Definitely,” answers Marincek’s col-league, Sebastian Leschka, MD. With the new scanners, the institute is not only lowering patient exposures, it is also saving time, money and hassle in the day-to-day workflow, thanks to the machines’ high scanning speeds and optimized workflows. “They have provided signifi-cant economic benefits,” says Leschka,

adding that the “next-next” generation scanner, the SOMATOM Definition Flash, promises to trump these improvements even more.

At the Heart of the MatterCardiac CT scanning at the Institute of Diagnostic Radiology has been revolutio-nized by the introduction of the SOMATOM Definition, Leschka notes. The hospital’s previous scanner had only half the Definition’s temporal resolution of 83 milliseconds. The lower temporal resolution of the previous system required that, prior to a scan, most patients’ hearts had to be slowed down

“We will always opt for the latest technology that offers the best results with the lowest possible dosage.”Prof. Borut Marincek, MD, Head of Radiology,

University Hospital Zurich


Business

by a dose of beta-blockers. This meant they needed to report to the hospital nearly two hours ahead of the scan – and wait about an hour for the beta-blockers to kick in. “Of course, we had to have extra space where patients could wait for the beta-blockers to take effect,” recalls Leschka, “and sometimes the waiting went into overtime because of schedule changes or other problems.”“With the new SOMATOM Definition,” says Leschka, “all we need now is 10–15 minutes in the CT room.” Workflow has simplified, and cardiac CT scans have climbed 20% from 2008 to 2009.” A significant source of this increase is represented by patients who previously would have undergone a purely diagnos-tic procedure (about 40% of all catheter-izations). Compared to a catheterization, a CT scan is lower in radiation, takes less time (minutes, as opposed to the better part of a day, including an overnight in the hospital) and more comfortable (non-invasive). And then there is the fi-nancial benefit: Leschka points out that a cardiac CT scan costs about CHF 800, while an equivalent catheterization costs nearly seven times as much, a whopping CHF 5,400.

“With the new scanners, the institute is not only lowering patient exposures, it is also saving time, money and hassle in the day-to-day workfl ow.”Sebastian Leschka, MD, Institute of Diagnostic Radiology,

University Hospital Zurich

Meanwhile, non-cardiac CT scans have benefited from the addition of the SOMATOM Definition AS. Its higher reso-lution allows CT-guided interventions to go more quickly and smoothly. In the case, for example, of extracting lung tissue via a needle, “With the old scan-ner,” remembers Leschka, “we often had to ask the patient to hold his or her breath and we could not see what was going on from some planes of view. With the Definition AS, no breath holding is need-ed, and we can see all we need to.”

Things Can Only Get BetterEven more will be seen with the Defini-tion Flash, the latest member of the SOMATOM Defintion family of CT scan-ners, one of which was recently deliv-ered to Zurich University Hospital’s Insti-tute of Diagnostic Radiology. Leschka and his colleagues are cautiously opti-mistic that the new technology might bring together the distinct disciplines of thoracic and cardiac scanning. Up to now, the heart has been, as Leschka puts it, a “black hole” in routine thoracic scanning. Because of the differences in resolution required for cardiac views, “We didn’t even bother to look at the heart

in a non-ECG-gated thoracic scan,” he points out. But the SOMATOM Definition Flash – which can cover the entire tho-rax in less than a second – could change that, because it can virtually conduct the two scans simultaneously.“We could combine excellent visualiza-tion of the coronary arteries and the thoracic-abdominal arteries in a single scan”, Leschka speculates. Or take the case of a patient who comes in with a vague chest pain. With a Definition Flash CT scan, “We could find out whether the problem is, say, in his pulmonary vessels, his aorta, his lungs or his heart. That would allow treatment to start more quickly, and we could do all the scanning without generating any extra radiation or cost.” Yet another case of, it takes money to make money” and save money and … most important, improve patient care and save lives as well.

Eric Johnson writes about technology, business and the environment from Zurich.


Clinical Results Cardio-Vascular

HISTORY

A male 64-year-old patient with positive nuclear stress test, and a medical history of coronary heart disease and coronary bypass surgery was seen at the depart-ment of Radiology.

DIAGNOSIS

Coronary artery disease, status post coronary artery bypass graft surgery, was determined.

Case 1Heart Perfused Blood Volume with SOMATOM Defi nition Dual Energy Scanning By Balazs Ruzsics, MD, PhD and U. Joseph Schoepf, MD

Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA

COMMENTS

A retrospectively ECG-gated Dual Energy CT exam shows myocardial blood vol-ume deficit of the inferior myocardium in confirmation of findings at stress nu-clear myocardial perfusion imaging. This finding is consistent with prior infarct in the right coronary artery territory.A color-coded iodine map shows the distribution of contrast agent within the myocardium in short axis (Fig. 1) and long axis (Fig. 2) reconstructions. The inferior/apical myocardium shows

decreased iodine content, representing chronic infarction. The infero-apical myocardial blood volume defect is also clearly visible on the 3D volume-ren-dered reconstruction in Fig. 3. The same Dual Energy CT dataset was used to visu-alize the coronary tree displayed as 3D volume-rendered reconstruction (Fig. 4) and delineating the left internal mam-mary artery and saphenous vein grafts without additional radiation or contrast medium administration.

EXAMINATION PROTOCOL

Scanner SOMATOM Definition

Scan mode DE Coronary CTA Rotation time 0.33 s

Scan area Heart Slice collimation 0.6 mm

Scan length 165 mm Slice width 0.75 mm

Scan direction Cranio - caudal Reconstruction increment 0.4 mm

Scan time 13 s Reconstruction kernel D30f and B25f

Tube voltage 140/80 kV Postprocessing syngo InSpace

Tube current 144 eff. mAs/ 165 eff. mAs syngo DE Heart PBV


Cardio-Vascular Clinical Results

3 VRT and Heart Perfused Blood Volume (PBV) data fused to visualize iodine distribution.

4 VRT of the heart showing the course of the bypass graft and native LAD.

1 Short axis reconstruction showing myocardial ischemia. 2 Long axis reconstruction with apical myocardial ischemia.

21

43



HISTORY

A 60-year-old female patient with known history of stent placement (right coronary artery, RCA), was referred for evaluation of recurrent, atypical chest pain. Presence and extent of coronary atherosclerotic plaque and stenosis as well as myocardial perfusion was as-sessed using a prospective coronary CT angiography and dynamic myocardial stress perfusion image acquisition. Find-ings included two consecutive subtotal occlusions in the intermediate and distal segment of the RCA (Figs. 1 and 2, arrows, RV= right ventricle, LV= left ven-tricle) and moderate calcified and non-calcified atherosclerotic plaque in the proximal segment of the vessel. In addi-tion, myocardial perfusion analysis (syngo VPCT Body-Myocardium) application re-vealed a corresponding segment of myo-cardial hypo-perfusion as indicated by delayed enhancement pattern in the myocardial segment (Figs. 3A and 3B, arrows). Fig. 3C displays the delayed myo-cardial enhancement pattern in the corre-sponding myocardial region of interest (as indicated by the arrow in Fig. 3B).

DIAGNOSIS

Subtotal occlusion of the RCA with cor-responding myocardial perfusion defect was detected by Cardiac CT image in the inferior wall.

Case 2SOMATOM Defi nition Flash: Dynamic Myocardial Stress-Perfusion By Konstantin Nikolaou, MD*, Fabian Bamberg, MD, MPH*, Alexander Becker, MD**, Ernst Klotz***, Thomas Flohr, PhD***

*Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany**Department of Medicine, Cardiology Division, University of Munich, Campus Großhadern, Munich, Germany***Business Unit CT, Siemens Healthcare, Forchheim, Germany

1 Volume-rendered cardiac CT image demonstrates the proximal subtotal occlusion of the right coronary artery (arrow) just distal to the acute marginal branch.

1


Topic


Scanner SOMATOM Definition Flash

Scan mode Stress Perfusion Scanning

Scan area Left ventricular

myocardium

Scan length 72 mm, shuttle

Scan direction Cranio-caudal

Scan time 28 s

Heart rate 60 bpm

Tube voltage 100 kV

Tube current 370 mAs/rot.

Volume 50 ml

Flow rate 5 ml/s

Start delay 18s

Dose Coronary CTA 2.4 mSv

Body-Myocardium

Dynamic Perfusion 9.6 mSv

Postprocessing syngo Volume Perfusion

CT Body

The dynamic myocardial perfusion imag-ing was performed using intravenous adenosine (140μl/kg min). Total radia-tion exposure including 2.4 mSv coro-nary angiography of the protocol was 12 mSv.

COMMENTS

This case demonstrates that cardiac CT imaging has the potential to provide information on coronary anatomy and hemodynamic relevance simultaneously. In this patient, both a coronary CT angiography and a dynamic myocardial perfusion scan were performed. Coro-nary CTA was acquired with a standard “Adaptive Sequence” protocol at a dose of 2.4 mSv, which is not further dis-cussed here.

Cardiovascular Clinical Results

2 Maximum Intensity Projection of the right coronary artery demonstrating two consecutive subtotal occlusions in the intermediate and distal segment of the right coronary artery (arrows). RV= right ventricle, LV= left ventricle.

3 Dynamic myocardial perfusion analysis reveals a segment of myocardial hypo-perfusion in the inferior wall (Figs. 3A and 3B, arrows) corresponding to the lesion in the right coronary artery. Fig. 3C shows temporal course of myocardial enhancement in normal (red curve) and ischemic (green curve) region of interest: upslope and peak are significantly lower.

2

3A 3B

3C



HISTORY

The patient was referred to the cardiology department in the Centre Cardio-Thora-cique de Monaco prior to vascular surgery. In addition to the previously performed doppler ultrasound, a Dual Energy scan was conducted in order to see the entire vascular status of the carotid arteries and the carotid stenosis morphology.

DIAGNOSIS

The patient examination revealed a bilateral high grade common carotid artery stenosis and severe calcified plaques in both internal and external

Case 3Dose Neutral Dual Energy Carotid CTA with SOMATOM Defi nition FlashBy Filipo Civaia, MD*, Philippe Rossi, MD*, Stéphane Rusek*, Andreas Blaha**

*Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco **Siemens Healthcare, Forchheim, Germany

carotid arteries, all close to the bifurca-tion. Dual Energy scan mode enables quick volume rendered (VRT) and maxi-mum intensity projections (MIP) without overlaying vertebra bodies of cervical spine to accurately measure the extent of the stenosis.

COMMENTS

The fast acquisition time of 6 seconds using Dual Energy technique from the aortic arch to the Circle of Willis did show a pure arterial contrast filling. No venous backflow obstructed the

viewing on the carotid arteries. Cardiac pulsation also did not impair the diag-nostic quality of the common carotids near the aortic arch.Dual Energy acquisition allows a fast separation of bones and vessels, even the closely embedded vertebral artery and basilar artery were well separated and diagnosed. The patient immediately underwent further treatment.



Scan mode DE Carotid Angio Rotation time 0.28 s

Scan area Carotid CTA Pitch 0.9

Scan length 354 mm Slice collimation 0.6 mm

Scan direction Caudo-cranial Slice width 0.75 mm

Scan time 6 s Reconstruction increment 0.7

Tube voltage 100/140 kV Reconstruction kernel D26

Tube current 104/90 mAs Volume 50 ml

Dose modulation CARE Dose4D Flow rate 4.5 ml/s

CTDIvol 8.24 mGy Postprocessing syngo InSpace;

syngo DE Direct Angio


Topic

1 Maximum Intensity Projec-tion (MIP) highlights calcified bilateral carotid artery plaques (arrows, Fig. 1A); inverted MIP, “angio like view” of the vascular status (Fig. 1B).

2 Dual Energy software sepa-rates contrast enhanced arteries (arrow) and bones/calcium (red; Fig. 2A). Axial MIP of the same slice position as Fig. 2A shows the relationship of lumen and plaque (arrow, Fig. 2B).

3 Curved maximum intensity reformations (MIP) of the right carotid artery (Fig. 3A); curved maximum intensity reformations (MIP) of the left carotid artery (Fig 3B).

4 Volume rendered image of the pure arterial enhancement, from aortic arch to circle of Willis.

1A 1B

2A 2B

3A 3B

4A 4B



1 VRT of the entire elongated aorta, highlighting stent in right iliaca commu-nis (arrow), RCA (arrowhead).

2 Maximum Intensity Projection (MIP) of the entire aorta showing stented right arteria iliaca communis (arrow).

Case 4SOMATOM Defi nition Flash Follow-up Examination After Stent Implantation for Ruptured Aneurysm By Sebastian Leschka, MD

Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

HISTORY

An 81-year-old male patient presented at the radiology department for a follow-up examination. Six weeks prior the patient had been delivered to the hospital for coiling and stent implanta-tion because of a ruptured aneurysm. Previous to implantation, the patient had complained of pain in the lower abdominal region. One day after stent implantation, a type II endoleakage appeared. Four days after intervention, an acute bleeding of the urethra due to removal of a permanent catheter was found. The scheduled follow-up exam was requested to indicate progress of convalescence.

DIAGNOSIS

During examination with the Dual Source CT SOMATOM Definition Flash scanner, supra-aortic vessels were shown to be normal. No pathologically increased lymph nodes could be found. There were no findings regarding pleural contusion or pneumothorax. Moderately decreased dorso-basal left-sided lung-ventilation was noted but no pathological pulmonary or mediastinal lesions could be detected.The abdomen was found to be adequate-ly perfused and the previously coiled right aorta iliaca interna was retrogradely supplied with blood. In the right-sided pelvis minor, the known interna aneu-

21


3 Non-per-fused, sack-like aneurysm with maximum dimension of 6.9 cm x 7.2 cm (arrow).

rysm, a non-perfused sack-like aneurysm with maximum dimension of 6.9 cm x 7.2 cm, was visible. Additionally, an arising, cyst-like hematoma (max. 6.4 cm x 3.3 cm) was detected. The boundary area of the hematoma showed increased contrast media uptake. The implanted stent in the right arteria iliaca communis showed a regular position not indicating any endoleak. No intraperito-neal fluid was visible. No pathological increased lymph nodes were found in the abdomen.

COMMENTS

The follow-up could be conducted quickly and progress of the patient’s convales-cence indicated with reliable image re-sults. Regular follow-up investigations for monitoring future recovery have been recommended. For the scan, only a total dose of 3.0 mSv was necessary.With one and the same scan, substantial coronary artery stenosis could be ex-cluded.



Scan mode Flash spiral

Scan area Thorax and Abdomen

Scan length 653 mm


Scan time 1.5 s

Tube voltage 100 kV / 100 kV

Tube current 320 mAs /rot

CTDIvol 2.83 mGy

DLP 201 mGycm

Dose 3.0 mSv

Rotation time 0.28 s

Pitch 3.2

Slice collimation 0.6 mm

Slice width 0.75 mm

Reconstruction 0.4 mm

increment

Spatial Resolution 0.33 mm

Reconstruction B26f

kernel

Volume 100 ml contrast

Flow rate 5 ml/s

Start delay 10 s

Postprocessing CT Cardiac Engine

3

4 VRT view of the coronaries; RCA, LAD, and LCX.

4

5 Curved planar refor-mation of the right coronary artery (RCA, arrow).

5



1 Abdominal aorta bypass graft (VRT) visualized with syngo Dual Energy Direct Angio.

Case 5Takayasu Arteritis with Atypical Aortic Coarctation: Follow-up Exam with Dual Energy CT By Satoru Kitano, MD, Junko Takahama, MD, Toshiaki Taoka, PhD, MD, Kimihiko Kichikawa, PhD, MD

Department of Radiology, Nara Medical University, Nara, Japan

HISTORY

A 49-year-old female patient came for a periodic follow-up CT after abdominal aortic bypass surgery. She had been di-agnosed with Takayasu arteritis and atypical aortic coarctation two years ago and had undergone descending aorta – abdominal aorta bypass surgery with vascular grafts. Reconstructions of the celiac trunk, the superior mesenteric ar-tery and bilateral renal arteries had suc-cessfully been performed. Now, she was referred to Dual Energy CT (DECT) for a follow-up examination.

DIAGNOSIS

A stenosis of the superior mesenteric artery was confirmed and collateral ves-sels, such as the internal thoracic artery, were clearly seen. No immediate inter-vention appeared to be necessary.

COMMENTS

Dual Energy CT scans are routinely used in our hospital for aortic and run-off CT angiography because syngo Dual Energy Direct Angio is a fast and reliable way to segment iodine contrast-enhanced ves-sels. Vessels of small diameters are clearly imaged, which is particularly use-ful when assessing vessel lumen or col-lateral blood flow.

1


Cardio-Vascular Clinical Results

2 Abdominal aortic bypass graft shows anas-tomosis area (MIP).

2

3 Superior mesenteric artery displayed in cmpr.

3 EXAMINATION PROTOCOL


Scan mode DE Thorax Abdomen

Scan area DE Aortic CTA

Scan length 626 mm


Scan time 27s

Tube voltage 140/80 kV

Tube current 90 eff. mAs / 351 eff. mAs

Dose modulation CARE Dose4D

CTDIvol 14.35 mGy

Rotation time 0.5 s

Pitch 0.7


Slice width 1.5 mm

Reconstruction increment 0.7 mm

Reconstruction kernel B30f

Volume 100 ml (370 mgI/ml)

Flow rate 3 ml/s

Start delay 20 s

Postprocessing syngo DE Direct Angio

5 Right renal artery. Course of right renal artery and left renal artery using cmpr visualization.

6 Left renal artery.

4 5 6

4 Celiac trunk in curved planar reformation (CMPR) technique.


Clinical Results Oncology

Case 6SOMATOM Defi nition Flash: Ruling out Cystic Fibrosis (CF) in a Pediatric Patient – Scan in 0.56 Seconds at 1 mSvBy Sedat Alibek, MD,* Michael Lell, MD,*Gundula Staatz, MD,** Andreas Blaha,***

* Institute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany

** Section Pediatric Radiology, Institute of Radiology, Friedrich-Alexander University

Erlangen-Nuremberg, Erlangen, Germany

*** Business Unit CT, Siemens Healthcare, Forchheim, Germany

HISTORY

The 10-year-old patient has a known allergic asthma disease. Due to recurrent dyspnoea, conventional chest X-ray im-aging was performed. Findings were de-scribed as acute and chronic inflamma-tory changes of the lung tissue. Due to

clinical symptoms consistent with those of cystic fibrosis, a standard sweat test was performed to measure the concen-tration of salt in the patient’s sweat. The test indicated elevated values. Conven-tional chest X-ray examinations did not

show clear signs of infiltrations but a rule-out was also not possible. The patient was referred to the pediatric hospital at the University of Erlangen. Radiologists there decided not to do fur-ther X-ray exams, but an ultra-low-dose CT scan was ordered to obtain accurate diagnostic information with maximum patient safety.

DIAGNOSIS

With the sub-second scan protocol, all acute and chronic pulmonary tissue changes like inflammatory changes as well as specific findings of Cystic Fibrosis such as bronchiectasis, mucoid impac-tions and necrotic changes could be ruled out. The short scan time of only 0.56 seconds did not require any seda-tion of the cooperative young patient.Following this CT scan, the patient could be discharged and no further work-up or follow-up was necessary.

COMMENTS

This high-resolution, non-contrast enhanced CT examination could reliably exclude specific findings indicative of cystic fibrosis. The ultra-low dose exami-nation of only 1 mSv and the short examination time improved the patient’s comfort during the scan tremendously.

1 No infiltrations are visible in this Minimum Intensity Projection (MinIP).

1


Oncology Results

5 VRT display of both lungs.

3 VRT of the thorax showing regular course of the bronchial tree; no abnormalities are visible.

4 Sagittal MPR of patients lung: no artefacts caused by breathing due to fast scan time.

34

2 Maximum Intensity Projection (MIP): coronal thoracic view.

5



Scan mode Flash Thorax Dose 1 mSv

Scan area Thorax Rotation time 0.28 s

Scan length 225 mm Pitch 3.0

Scan direction Cranio-caudal Slice collimation 0.6

Scan time 0.56 s Slice width 0.75 mm

Tube voltage 100/100kV Reconstruction increment 0.7 mm

Tube current 32 eff. mAs Spatial Resolution 0.33 mm

Dose modulation CARE Dose4D Reconstruction kernel B26

CTDIvol 1.31 mGy Postprocessing syngo InSpace 4D

2 3


Clinical Results Neurology

Case 7Moyamoya Disease: Whole Brain Perfusion CT By Thomas C. Lee, MD, Aaron Sodickson, MD, PhD and Srinivasan Mukundan Jr., MD, PhD

Department of Radiology, Brigham and Women’s Hospital, Boston, USA

HISTORY

A middle-aged woman who initially pre-sented with worsening left-sided weak-ness was diagnosed with Moyamoya disease. Moyamoya is a term originating from the Japanese word for puff of clouds, referring to the tiny collateral vessels which form to reconstitute idiopathic chronic occlusion of the middle cerebral artery (MCA). For further evaluation a whole brain perfusion study was per-formed with the Adaptive 4D Spiral scan mode.

DIAGNOSIS

The CTA of the cervical and intracranial vessels (Fig. 1A) shows a marked steno-sis of the supraclinoid right internal carotid artery (ICA) (Fig. 1B), right carotid terminus and proximal right M1 segment with multiple collateral vessels reconstituting the right MCA. The com-mon carotid, cervical internal carotid, external carotid and vertebral arteries re-main patent without significant stenosis. There was mild to moderate stenosis of the supraclinoid left ICA just proximal to the terminus. The left MCA remained normal. There was a small infundibulum of the left posterior communicating artery origin. Perfusion imaging showed relatively normal cerebral blood volume but markedly delayed mean transit time and cerebral blood flow within the right MCA territory.The patient subsequently underwent a right external carotid/internal carotid (ECIC) bypass using a superficial temporal to middle cerebral artery anastomosis.

1 The CTA of the cervical and in-tracranial vessels (Fig. 1A) shows a marked stenosis of the supraclinoid right ICA (Fig. 1B), right carotid termi-nus and proximal right M1 segment with multiple col-lateral vessels re-constituting the right MCA. Because of the expected stenosis, the acqui-sition was slightly delayed, resulting in venous contami-nation.

1A

1B


Neurology Clinical Results

COMMENTS

CT perfusion (CTP) has been performed for MCA occlusion in the past but was typically limited to a 2 cm thick slab of brain at the level of the basal ganglia. This case of Moyamoya disease is de-scribed in which the use of the Adaptive 4D Spiral scan mode allows simultaneous perfusion imaging of the entire brain. The perfusion findings in a patient with Moyamoya disease mimics the findings one could see in acute stroke, where a clot occludes the MCA. This technique provides comprehensive whole brain perfusion imaging in acute stroke patients, as well as in the chronic setting of Moyamoya disease.


Scanner SOMATOM Definition AS+ SOMATOM Definition AS+

CT Angiography CT Volume Perfusion

Scan area Head and Neck Head

Scan length 320 mm 96 mm (Adaptive 4D Spiral)

Scan time 4s 45 s, one scan every 1.5 s

Scan direction Cranio-caudal Cranio-caudal

Tube voltage 100 kV 80 kV

Tube current 250 Quality ref. mAs 250 eff. mAs

Rotation time 0.5 s 0.3 s

Slice collimation 0.6 mm 0.6 mm

Slice width 0.75 mm 5 mm

Reconstruction kernel H20 H20

Spatial Resolution 0.33 mm 0.33 mm

Volume/Contrast/Flow rate 50ml / 370 / 4ml/s 40ml / 370 / 6 ml/s

50ml / Saline / 4ml/s 40ml / Saline / 6 ml/s

Postprocessing syngo Neuro DSA CT syngo VPCT Neuro

2 Volume Perfusion CT (VPCT) enables perfusion parameter analysis for the whole brain. VPCT indicates relatively normal cerebral blood volume (middle row) but markedly delayed mean transit time (lower row) and cerebral blood flow (upper row) within the right MCA territory. This imaging is consistent with the patient’s Moyamoya disease.

2


Clinical Results Acute Care

HISTORY

A 62-year-old male patient with a known type B aortic dissection affecting the entire descending and abdominal aorta was referred to the radiology depart-ment of the German Heart Center Munich for a follow-up examination after stenting of the right renal artery. Additionally, an actual vascular status was needed in preparation for implan-tation of a thoracic aortic stent.The examination was done with the new Dual Source Scanner SOMATOM Definition Flash, utilizing ultrafast Flash spiral acquisition.

DIAGNOSIS

Aortic dissection originates closely distal to the ostium of the left subclavian artery. The true lumen of the descend-ing thoracic aorta is very narrow and comprises only about 1/3 of the aortic lumen. The cranial part of the false lu-men shows a good contrast-enhance-ment. The worse contrast-enhanced caudal part of the false lumen indicates a low blood flow und thus predisposition to thrombosis in the false lumen. The coeliac trunk, the superior mesenteric artery and both renal arteries are fed by a very small sickle shaped true lumen of the abdominal aorta.By contrast the inferior mesenteric ar-tery originates from the barely perfused false lumen, therefore its proximal part is not contrast-enhanced. The distal part

Case 8SOMATOM Defi nition Flash Provides the Entire Extension of Aortic Dissection in Just 2 Seconds Scan Time By Eva Hendrich, MD*, Stefan Martinoff, MD*, Tanja Gassert **, Andreas Blaha**

*Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany**Business Unit CT, Siemens Healthcare, Forchheim, Germany

1 Aortic arch with RCA (Right coronary artery) and LAD (Left anterior descending): no motion artifacts are visible.

however is well collateralized over Riolan’s anastomosis.The dissection ends 2 cm above the aortic bifurcation. Due to the acquisition time of only 2 seconds for thorax and

abdomen, it was possible to freeze the motion of the coronary arteries. The coronary arteries show significant calci-fications, especially in the proximal part of the right coronary artery (RCA).

1


Acute Care Clinical Results

COMMENTSDue to the lack of distance between the cranial end of the aortic dissection and the ostium of the left subclavian artery,

2 Maximum Intensity Projection (MIP) of the entire aorta (arrow) highlighting stented and patent right renal artery (arrowhead).

3 Sagittal MIP display of aortic dissection, sickle shaped true lumen (arrowhead).

4 True and false lumen (arrowhead); collaterals of Riolan’s anastomosis (arrow).

it will be difficult to place an aortic stent. The relation of true and false lumen of this type B dissection was quickly and accurately displayed. Because of the

extremely fast scan time of only 2 sec-onds for 69 cm and highest temporal resolution of 75 ms, it was easily possi-ble to freeze motion of the aortic arch.



Scan mode Flash Thorax Abdomen Rotation time 0.28 s

Scan area Aortic CTA Pitch 2.1

Scan length 685 mm Slice collimation 0.6 mm

Scan direction Cranio-caudal Slice width 0.75 mm

Scan time 2 s Reconstruction increment 0.70 mm

Tube voltage 120 kV Reconstruction kernel B20f

Tube current 180 Quality ref. mAs Volume 80 ml

Dose modulation CARE Dose4D Flow rate 4.5 ml/s

CTDIvol 10.5 mGy Postprocessing syngo InSpace4D

3 42


Clinical Results Acute Care

1 Contrast enhanced CT: mural thrombus in main pulmonary artery trunk (Fig. 1A); contrast enhanced CT: mural thrombus in peripheral vessel (Fig. 1B); Dual Energy CT Lung PBV: perfusion defect, axial view (Fig. 1C).

HISTORY

A 70-year-old female on dialysis treat-ment for chronic renal failure noticed herself becoming increasingly breathless on exertion. She was referred to our de-partment for a chest X-ray and a chest CT. Hilar enlargement was seen on the chest plain film and a mosaic perfusion pattern was seen on the chest CT images suggesting chronic pulmonary embo-lism. The patient was then referred for a contrast enhanced Dual Energy CT scan to evaluate the perfused blood volume (PBV) with Dual Energy Lung PBV and for a lung perfusion scintigraphy examina-tion with 99m Tc-MAA (99m Tc Albumin aggregated).

Case 9Dual Energy CT Imaging of Chronic Pulmonary Embolism Hiroaki Tanaka, MD*, Masaya Yamamoto, MD*, Kouki Watanabe, MD**, Hideyuki Saeki, MD**, Taizo Morita*, Tadashi Asami*, Terue Murakami*

*Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan**Department of Cardiovascular Internal Medicine, Saiseikai Matsuyama Hospital, Matsuyama, Japan

DIAGNOSIS

On the Dual Energy CT images, mural thrombi were noted in the main pulmo-nary artery trunk as well as in peripheral vessels. The Dual Energy lung PBV imag-es revealed perfusion defects in lung ar-eas matching the location of the throm-bi. The lung perfusion defects found on lung perfusion scintigraphy correspond-ed well with those found on the Dual Energy Lung PBV images.

COMMENTS

With Dual Energy CT Lung PBV post-pro-cessing, contrast enhanced CT and per-fused blood volume imaging can be combined. The simultaneous visualiza-tion of thrombi as well as lung perfusion defects is expected to improve the diag-nostic accuracy of pulmonary embolism. Structural and functional evaluation of the lung could be performed in one single scan which has the potential to reduce dose to the patient.

1A 1B 1C


Acute Care Clinical Results

4 Lung perfusion scintigraphy image in comparison to syngo DE Lung PBV: perfusion defects.



Scan mode DE Lung

Scan area Thorax

Scan length 369 mm


Scan time 12 s

Tube voltage 140/80 kV

Tube current 56 eff. mAs / 291 eff. mAs

CTDIvol 11.57 mGy

Rotation time 0.33 s


Slice width 1.5 mm

Reconstruction increment 1 mm

Reconstruction kernel D30f

Volume 100 ml of 300 mgl/ml

Flow rate 3 ml/s

Start delay 20 s

Postprocessing syngo DE Lung PBV

2 Contrast enhanced CT: coronal view showing a thrombus (arrow). 3 Dual Energy CT Lung PBV: perfusion defect, coronal view.

2 3

4


Science

Dose-Optimized CAD Diagnostics At the University Medical Center in Mannheim, Germany, a comparative study on intra-individual diagnostic precision and radiation exposure of cross-section-al imaging procedures used to diagnose coronary artery disease is carried out. It aims at making an important contribution to the development of new stan-dardized guidelines – not only for diagnosis, but also treatment and aftercare.

By Hildegard Kaulen, PhD

In addition to conventional coronary angiography, imaging procedures used in the diagnosis of coronary artery dis-ease (CAD) include non-invasive cross-sectional imaging procedures such as coronary computed tomography angio-graphy (CTA), calcium score measure-ment, cardiac MR, and myocardial scintigraphy. A pioneering comparative assessment of all four procedures is currently being carried out at the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Center Mannheim. The aim is to develop a modern diagnos-tic algorithm for CAD, in which diagnos-tic precision and radiation exposure are placed in optimal proportion to one an-other. The study is being supported by Germany’s Federal Office for Radiation Protection (BfS). Despite major advances in treatment, cardiovascular diseases remain the num-ber-one cause of death in western indus-trial nations. Early forms and clinically manifest stages must be recognized consistently in order to further reduce morbidity and mortality, without placing undue radiation on patients during ex-aminations. The challenge faced by im-aging cardiac diagnostics is exemplified by two key questions: Which procedures should be used to examine patients with suspected CAD, and how is it possible to create an optimal balance between diagnostic safety and patient exposure?

Procedural Pros and Cons EvaluatedUntil now, coronary angiography reigned

supreme as the gold standard, offering maximum precision in the detection of coronary artery stenoses and permitting immediate interventional treatment. However, it is an invasive procedure which, albeit rarely, can result in life-threatening complications such as strokes in worst-case scenarios. Additional draw-backs are radiation exposure and the lack of a depiction and characterization of non-stenosing artherosclerotic coronary plaque. As a result, non-invasive sectional imaging procedures are now being used increasingly in CAD-diagnosis. However, these procedures also exhibit various ad-vantages and disadvantages. The strength of CTA lies in its high nega-tive predictive value, which permits the exclusion of relevant coronary artery stenoses in 95% of cases. One disadvan-tage is the radiation exposure linked to the CT process, which can amount to up to 20 mSv, depending on patient factors (such as weight, heart rate) and the tech-nique and equipment used. Although Cardiac MR omits the use of X-ray radia-tion, it is only possible to draw conclu-sions about the coronary arteries indi-rectly via perfusion and wall movement. As regards myocardial scintigraphy, radia-tion exposure is relatively low, but the spatial resolution is inferior to that of Car-diac MR. Here, too, the degree of stenosis is determined indirectly via the accumula-tion of nuclides in the myocardium.Stefan Schönberg, MD, Director of the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Cen-ter Mann heim, and his associate chair and section chief for cardio-thoracic

“We must aim to develop methods which provide the same diagnostic and clinical results for the patients everywhere and at all times – with the same level of radia-tion exposure.”

Stefan Schönberg, MD, Director of the Institute of Clinical Radiology and Nuclear Medicine at the University Medical Center Mannheim, Germany.


Science

imaging, Christian Fink, MD, have now embarked on a study commissioned by the BfS which could make an important contribution to the development of standardized guidelines for use in CAD diagnostics. The study will be compiled in close collaboration with Martin Borggrefe, MD, Director of the 1st Department of Medicine, Cardiology, and Tim Süselbeck, MD, Head of the Cath Lab and Borggrefe’s deputy and senior consultant.

Expectations for the StudyFink describes the study’s format as fol-lows: “The patients will be randomized into two groups in order to keep study-related radiation exposure to a mini-mum. All patients will be given the gold standard test, a coronary angiography. One of the cross-sectional imaging test linked to radiation exposure (CTA or myo-cardial scintigraphy) will subsequently be carried out, depending on the random-ization. Finally, patients will also receive a cardiac MR as a procedure which does not rely on ionizing radiation. A patient’s pre-test probability for CAD decides whether he or she is suitable for study participation. This is calculated on the basis of the physical examination, the ECG and the risk profile. Patients with low pre-test probability are not considered for the study, and are provided with con-ventional further treatments in accor-dance with recommendations issued by Heart Societies, this without the use of additional imaging diagnostics. The fo-cus is placed on the evaluation of meth-ods in patients with a moderate pre-test

probability, whose risk of CAD lies be-tween 10% and 90%. Here, we aim to use the study to create more clarity, demonstrate how comparable the results of the individual methods are and illus-trate the risks and advantages associat-ed with the various examinations. The data can then help generate concrete procedural recommendations for clinical practice.”However, in Schönberg’s view, diagnos-tics is just one aspect of the development of the standardized guidelines. “The entire process, from diagnosis and treat-ment to aftercare, should be analyzed in the planning and implementation stag-es,” he says. “The objective is to create an optimal balance between outcome and exposure, and to monitor precisely how the entire process affects the reduc-tion of mortality and morbidity in the case of CAD. Equipment technology and an optimization of examination para-meters play a decisive role here, in addi-tion to patient selection and risk calcula-tion regarding subsequent coronary events. We must aim to develop methods which provide the same diagnostic and clinical results for the patients every-where and at all times – with the same level of radiation exposure. The individual procedures vary too greatly at present. We hope that the study will go some way toward remedying this.” In this context, Schönberg expects im-portant progress in terms of equipment technology. The minimum requirement for CTA is a 16-slice CT. But 64-slice CT systems guarantee higher diagnostic reliability. Mannheim has been using a

64-slice Dual Source CT for the purposes of cardiac diagnostics for two years now. With the release of the SOMATOM Definition Flash, this generation of equipment has now been developed further. This device sets new industry standards in terms of temporal and spatial resolution and radiation expo-sure. Table movement of 45 centimeters per second, rotation time of 0.28 sec-onds, and a 128-slice Dual Source con-figuration ensure that a CTA can be taken in just 250 milliseconds, or a single cardiac cycle. This technology also means that a CTA performed with the SOMATOM Definition Flash emits routine doses of 1 mSv, if not lower. Says Schönberg: “After the study’s evaluation, we will look closely at how high the residual exposure is, taking account of all degrees of freedom, and its ratio to the overall outcome. This should dem-onstrate which guidelines are justified and which are not.” The study, led by Fink, has been in progress for some months. However, several more will pass before the complete results are pub-lished. They will certainly make a major contribution to the development of a modern diagnostic algorithm.

Hildegard Kaulen, PhD, is a molecular biolo-gist. After positions at Rockefeller University in New York and the Harvard Medical School in Boston, MA, USA, she has worked since the mid-1990s as a freelance science journalist for leading newspapers and scientific journals.

“We aim to use the study to create more clarity, demonstrate how comparable the results of the individual methods are and illustrate the risks and advantages associated with the various examinations. The data can then help generate con-crete procedural recommendations for clinical practice.”

Christian Fink, MD, Associate Chair for Clinical Operations and Section Chief of Cardiothoracic Imaging of the Institute of Clinical Radiology, University Medical Center Mannheim, Germany.


Science

The high-pitch spiral acquisition mode of the SOMATOM Definition Flash CT system provides high temporal resolution and fast image acquisition both at a very low level of radiation dose. Synchronizing the image acquisition in this Flash mode with the ECG-signal opens the field for several potential applications that could previ-ously only be performed at relatively high radiation dose. In comparison to conven-tional ECG-synchronized CT protocols, in the Flash mode the ECG-gating do not re-quire reduction of the pitch value, there-fore, the benefit of ECG-synchronization comes without a radiation dose penalty. The list of potential applications includes coronary CT angiography in a single heartbeat, evaluation of patients with acute chest pain and after coronary by-

First Study Results Using High-Pitch Spiral Acquisition in the Dual Source SOMATOM Defi nition Flash CT By Sebastian Leschka, MD, Gudrun Feuchtner, MD, Hatem Alkadhi, MD

Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

pass graft implantation, as well as the im-plementation of ECG-gating in CT angio-graphy of the thoracic aorta. Recently, two research studies have been completed in the Institute of Diagnostic Radiology, Zurich University Hospital. The first study (Fig. 1) observed the diagnos-tic accuracy for the assessment of coro-nary stenosis in 35 patients in compari-son with cardiac catheterization. Inclusion criterion was a heart rate of less than 60 bpm. Patients with high body mass index (BMI) were not excluded. The triggering phase for image acquisition was set at 60% of R-R interval. Two inde-pendent radiologists rated the image quality of each coronary artery segment on a 4-point scale and assessed the pres-ence of substantial coronary artery steno-

sis defined as luminal diameter reduction exceeding 50% of the reference diameter. The Cardiac Flash scan was successfully performed in all patients. Diagnostic im-age quality was obtained in 99% of coro-nary artery segments (455/459) and in 97% of patients (34/35). The diagnostic accuracy of the Flash mode for the detec-tion of coronary stenosis was excellent with sensitivity, specificity, positive and negative predictive value of 94%, 96%, 80%, and 99% per segment and 100%, 91%, 88%, and 100% per patient, respec-tively. Average radiation dose was in the sub-millisievert range (0.9±0.1mSv). In a second study (Fig. 2) the perfor-mance of ECG-gated Flash CT acquisitions was investigated for imaging the coro-nary arteries in CT angiographic scans



Study 1 Study 2

Scan mode Flash Spiral Cardio Flash Spiral ThAbd

Scan area Heart Thoracic aorta (n=33); thoracic-abdominal aorta (n=67)

Scan length 117 ± 11 mm 340 ± 25 mm (thoracic aorta), 638 ± 35 mm (thoracic-abdominal aorta)

Scan direction Cranio-caudal Cranio-caudal

Scan time 0.27 ± 0.05 s 0.88 ± 0.06 s (thoracic aorta), 1.67 ± 0.15 s (thoracic-abdominal aorta)

Tube voltage 100 kV 100 kV

Tube current 320 mAs/rot. (CARE Dose4D) 320 mAs/rot. (CARE Dose4D)

Effective radiation dose 0.9 ± 0.1 mSv 2.3 ± 0.3 mSv (thoracic aorta), 4.4 ± 0.5 mSv (thoracic-abdominal aorta)

Rotation time 0.28 s 0.28 s

Pitch 3.4 3.2

Slice collimation 0.6 mm 0.6 mm

Slice width 0.6 mm 0.6 mm

Reconstruction increment 0.4 mm 0.4 mm

Spatial Resolution 0.33 mm 0.33 mm

Reconstruction kernel B26f B26f

Contrast volume 60 ml 100 ml

Start delay Bolus tracking, ascending aorta, Bolus tracking, ascending aorta, threshold 100 HU, delay 10 s

threshold 100 HU, delay 10 s


Topic

1 A 58-year-old woman, scanned with Flash Spiral Cardio (heart rate 58 bpm, heart rate variability 1.0 bpm). Excellent image quality of the coronary arteries and absence of substantial coronary stenosis in the right coronary artery (Fig. 1A, curved planar reformation in MIP technique) and of the left anterior descending artery (Fig. 1B, curved planar reformation in MIP technique). Volume rendered images of the heart from a superior (Fig. 1C) and an inferior perspec-tive (Fig. 1D) highlight the excellent depiction of even small diameter side branches. The absence of substantial stenosis was confirmed by cardiac cathe-terization of the right and left coronary artery (Fig. 1E). The effective radiation dose was 0.86 mSv for the CT evaluation of the entire heart.

performed for the evaluation of the tho-racic and thoracic-abdominal aorta in 100 consecutive patients. All patients, irrespective of their heart rates were in-cluded in this study. Image quality of each coronary artery segment was rated by two independent radiologists on a 3-point scale. The effect of the average heart rate and the heart rate variability on image quality was statistically tested. The average scan time was 0.88 ± 0.06 s for thoracic and 1.67 ± 0.15 s for thorac-ic-abdominal CT. The average heart rate was 67 ± 16 bpm (range, 41 –135 bpm) and heart rate variability was 3.5 ± 4.9 bpm (range, 0 – 24.5 bpm). Diagnostic image quality was obtained in 97.2 % of coronary segments (1387/1417). In 83% of patients, all coronary artery segments

were visualized with diagnostic image quality. All patients with an average heart rate <63 bpm and a heart rate variability of <1.2 bpm had diagnostic image quality of their entire coronary artery tree. How-ever, diagnostic image quality of all coro-nary segments was obtained even in pa-tients with a heart rate of 108 bpm and a regular heart rhythm. Average radiation dose was 2.3 ± 0.3 mSv for thoracic and 4.4 ± 0.5 mSv for thoraco-abdominal CT angiography.In conclusion, both studies reveal excel-lent performance of the Flash acquisition mode for imaging of the coronary arter-ies. Cardiac Flash CT is highly accurate for the assessment of substantial coronary stenosis in patients with a heart rate <60 bpm and provides an excellent visu-

alization of the entire heart at sub-milliSievert radiation doses. In patients with a heart rate <63 bpm and a heart rate variability <1.2 bpm, high-pitch ECG-gated Dual Source CT angiography of the thoraco-abdominal aorta delivers a diagnostic visualization of the coronary arteries at a low radiation dose. Thus, in ECG-gated Flash acquisitions performed for evaluation of the aorta, the coronary arteries are visualized for free in patients with low and regular heart rates, and thereby radiation dose is reduced by a factor of 2-3 compared to CT angio-graphy protocols with a standard pitch value.

1. Leschka S, et al. Eur Radiol 2009, published, PMID: 19760229

2. Goetti R et al. AJR 2009, accepted pending revision

1A

2 A 62-year-old man was scanned with Flash thoracic-abdominal CT angiography (heart rate 56 bpm, heart rate variability 6.3 bpm). Volume rendered image (Fig. 2A) demonstrates excellent image quality of the complete vasculature includ-ing the coronary arteries. The arrow denotes the right coronary artery (RCA). Note clear depiction of celiac artery aneurysm and iliac stent graft. Curved planar reformation in MIP technique (Fig. 2B) pro-vides motion artifact-free visualization of the RCA and circumflex artery (CX). Radiation dose was 4.6 mSv for the complete thoracic-abdominal CT an-giography of the aorta and the coronary arteries.

1C1B1A

1D

2A 2B

1E

RCA

RCA

CX


Science

Relevance of biological X-ray effectsThe damaging effect of X-rays on bio-logical tissues was observed shortly after X-ray’s discovery. Over the years it has been a dream of scientists to successfully investigate the impact of radiation on the cells. However, previous approaches for the determination of X-ray induced DNA damages failed due to their low X-ray sensitivity, especially in dose ranges as they are used in diagnostic radiology.During the past several years, techniques for dose reduction in computed tomogra-phy have received increasing attention. For the calculation of the X-ray dose de-livered during CT, physical measurements with ionization chambers as well as mathematical operations such as Monte-Carlo simulations and registration of ex-posure parameters like computed tomo-graphy dose index (CTDI) and dose length product (DLP) are in use. Although these techniques allow an estimation of the radiation exposure, they do not con-sider biological X-ray interactions. Today we know that apart from the dose de-posed, individual factors like the DNA repair capacity, the patients’ constitution and the application of iodinated contrast media have an influence on X-ray in-duced DNA damages.DNA double-strand breaks (DSBs) are among the most significant X-ray induced DNA lesions since they can initiate car-cinogenesis. A novel approach allows the determination of these DNA damages in peripheral blood lymphocytes and pro-vides an accurate estimate of biological

Analysis of DNA Double-Strand Breaks Promises New View of Dosimetry in CTBy Michael A. Kuefner, MD

Institute of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany

1 �H2AX foci in blood lymphocytes: example of in vivo samples obtained from a patient before (Fig. 1A) and 30 minutes after (Fig. 1B) cardiac CT (spiral data acquisition with retrospective ECG-gating, total DLP 813 mGy . cm). Every focus represents one DNA double-strand break.

1B

1A


Science

radiation effects. Compared to previous biodosimetric measurements, this new technique is much more sensitive, covers the dose range of radiologic diagnostic procedures, and allows the determination of DSB induction after irradiation with very low doses.

Determination of DNA double-strand breaksThe phosphorylation of the histone variant H2AX is one of the earliest reac-tions of the cell after the formation of DSBs. Using a specific primary antibody against the phosphorylated H2AX (termed �H2AX) and a fluorescent sec-ondary antibody, distinct foci can be detected within the cell nuclei by fluores-cence microscopy, where each focus rep-resents one DSB (Fig. 1). The number of radiation induced DSBs can be calculated by subtracting foci number of corre-sponding pre-exposure controls from foci levels obtained in blood lymphocytes after CT scans. These excess foci yields correlate with the deposited dose.An estimation of the biological dose is possible by the relation of the in vivo obtained DSB levels to those of individual in vitro irradiations with defined X-ray doses.

DNA double-strand breaks induced during CTIn patients undergoing CT, a reliable de-termination of in vivo DNA DSBs is possi-ble 30 minutes after the scan. At 30 min-utes the number of X-ray induced DSBs correlate well with the dose length product, a well-established exposure parameter in computed tomography. Thereafter, in patients without a repair deficiency, a rapid repair of DSBs can be

observed and 24 hours after the CT the pre-exposure background values are reached. Apart from the dose deposed, there are further individual factors that have an in-fluence on the DNA damage levels. The intravenous application of iodinated con-trast media can lead to a 30% elevation of the in vivo DSB yields compared to patients undergoing native CT scans. The repair capacity is dependent on the age of the patient - in older patients DSBs are repaired more slowly than in younger in-dividuals. Finally, the damage level is de-pendent on the patient’s constitution. At the same dose length product we found a negative correlation between the DSB levels and the body mass index. This indi-cates that the biological dose compared to the DLP is rather overestimated in obese patients whereas it is underesti-mated in slim patients and confirms previous studies using the Monte-Carlo simulation.Cardiac CT represents a very interesting technique for the biological dose estima-tion since various scan parameters and data acquisition protocols have an influ-ence on the radiation dose. In our collec-tive of patients undergoing coronary CTA using the SOMATOM® Definition and the SOMATOM Definition Flash scanner, we observed a reduction of the DSB levels by a 100 kV protocol compared to 120 kV. Using the Dual Source CT scanner with a helical data acquisition protocol with retrospective ECG-gating, a mean of 0.39 DSBs per cell induced during CT was obtained 30 minutes after exposure. In those patients the dose-reducing effect of higher pitch values was negated by the use of a wider pulsing window required by higher heart rates (40–70% instead of

References:1 Grudzenski S, Kuefner MA, Heckmann MB, Uder

M, Lobrich M. Contrast media-enhanced radiation

damage caused by CT examinations. Radiology.

2009 (Epub ahead of print).

2 Kuefner MA, Grudzenski S, Schwab SA, Wieder-

seiner M, Heckmann M, Bautz W, Lobrich M, Uder

M. DNA double-strand breaks and their repair in

blood lymphocytes of patients undergoing angio-

graphic procedures. Invest Radiol.

2009;44(8):440-6.

3 Kuefner MA, Grudzenski S, Schwab SA, Azoulay S,

Heckmann M, Heinrich M, Lobrich M, Uder M.

Strahleninduzierte DNA-Doppelstrangbrüche

nach Angiographien verschiedener Körperregionen.

Fortschr Röntgenstr. 2009;181(4):374-80.

4 Lobrich M, Rief N, Kuhne M, Heckmann M, Fleck-

enstein J, Rübe C, Uder M. In vivo formation and

repair of DNA double-strand breaks after computed

tomography examinations. Proc Natl Acad Sci U S

A. 2005;102:8984-9.

70–70%). In patients undergoing coro-nary CT angiography using sequential data acquisition with prospective ECG triggering a mean of 0.12 DSBs per cell was obtained after the scan. In patients undergoing high-pitch CT angiography using the Definition Flash scanner, the DNA damage level could be further re-duced to a mean of 0.05 DSBs per cell, which means – depending on the scan protocol – a reduction of the biological dose of 80–90% compared to low-pitch spiral data acquisition.

Conclusion

Using the �H2AX immunofluorescence microscopy, considerable DNA damages can be observed following CT, but DSBs are repaired quickly. On the one hand, it is essential to carefully adapt the scan protocols in order to avoid unnecessary X-ray induced DNA damages. On the oth-er hand, new developments in CT like the Flash speed scanning can lead to a sub-stantial reduction of X-ray induced DSBs.


Topic

Funding to Maintain, Improve, and Expand Services in an Uncertain Economy

Chester County Hospital (CCH), West Chester, Pennsylvania, USA, chose an offer from SFS for leasing and financing diagnostic high end equipment.

www.usa.siemens.com/financial

For the Chester County Hospital (CCH), West Chester, Pennsylvania, USA, the bond market troubles that emerged in 2008 caused the hospital’s leadership to question whether it could continue to move forward with its planned imaging equipment acquisitions. The hospital had traditionally funded these types of capital expenditures with a tax-exempt bond. But, with the bond market essen-tially collapsing, this was no longer a viable option. Fortunately, the 238-bed non-profit, acute-care hospital was able to acquire the new equipment via financ-ing options offered through Siemens Financial Services (SFS).CCH is not the only hospital challenged with finding financing in this economy. With the financial markets in disarray and the recession in full swing, hospitals are facing an economic “perfect storm.”

Many are seeing losses in the market value of their investments, delayed reim-bursement payments for Medicaid pa-tients, increased bad debt and/or charity care, and, like CCH, loss of access to debt via the bond market. The cumulative effect of these pressures can mean delayed or cancelled projects. Yet hospitals are still expected to provide healthcare services for their communi-ties, maintaining, improving, and even expanding services if that’s what is nec-essary to offer the best possible patient care. To help, SFS provides a comprehensive range of equipment financing solutions that can help enable organizations to fund new technology. This is a particu-larly attractive option in today’s market conditions. There are three basic types of equipment financing offered in USA:

Fair Market Value Lease – ideal for customers who:■ are concerned about avoiding poten-

tial technology obsolescence issues in the future, or

■ may be concerned with meeting certain budget requirements, or

■ are trying to manage certain financial ratios and need to have the financing structured to achieve off-balance sheet treatment (to look like an oper-ating expense).

These leases typically provide customers with the lowest monthly payments (as compared to the other equipment leasing options) since they are, in essence, only paying for the use of the system during the term of the lease. At the end of the lease, the customer has the option to purchase the equipment at the then fair market value of the equipment, enter into a renewal, or return the equipment.

Finance Lease – ideal for customers who:■ plan to work with equipment over

long life-span (not at risk for techno- logical obsolescence), or

■ prefer 100% financing options (like a traditional bank loan) and intend to own the equipment at the end of the financing.

Tax-Exempt Lease – ideal for customers who:■ are qualified tax-exempt entities, and■ typically like to finance capital projects

by issuing tax-exempt bonds.

In addition to SFS equipment financing products, other financing solutions avail-able to healthcare providers include re-volving lines of credit, term loans, and real-estate financing. For more informa-tion about SFS services in the USA, visit the following website. The local Siemens representatives can be contacted as well.

Life


Topic

As Head of the CT Department in the Shandong Medical Imaging Research In-stitute, Professor Xu Zhuodong and his team of 20 doctors and technicians work a very busy schedule. “On an average day, we have about 200 patients in need of a CT scan,” Xu says. Equipped with state-of-the-art technology, the institute is one of the very best in China. This ex-cellent reputation as a leader in medical imaging means that Xu and his staff – as well as the CT scanners they are oper-ating – are constantly working at full capacity. Consequently, the systems have to be extremely reliable. “A smooth work-flow is essential for efficient work as well as for the satisfaction of our patients,” Professor Xu says. This is why normal wear and tear consti-tutes a challenge. CT tubes – a part abso-lutely vital to system availability, have an inherently limited life span not due to any malfunction in the system. At some point, the tubes are simply worn out, just like light bulbs in a lamp. And as in the case of the light bulb, the timing of the breaking point cannot be predicted with anything approaching precision. So it was – until early in 2009, when Siemens introduced the TubeGuard option for its customers. As an optional additional service offering to the Siemens Guardian Program, TubeGuard can, with amazing accuracy, predict the ma-jority of all CT tube failures within the SOMATOM® Definition family. As a result, total tube breakdowns, or “hard downs,” are avoided, permitting instead a proac-tive tube exchange, or “soft down.”

Once TubeGuard has been installed, sensors proactively monitor the tube functions via real-time data flow with Siemens Remote Service (SRS) – the effi-cient and comprehensive infrastructure for medical equipment-related remote services. Based on TubeGuard’s complex algorithms and customer-specific system usage data, the tube monitoring experts perform an ongoing assessment of re-maining tube life. One example of moni-toring is the measurement of cooling per-formance. The TubeGuard functionality is based on sensor data of oil temperature, gantry temperature and oil pressure. If the cooling performance falls under de-fined limits and the tube could possibly fail, the customer is informed within a dedicated time limit. As a result, the tube

change can be made during a planned service visit, such as during prescheduled system maintenance – without causing unnecessary downtime, delays and inter-ruptions in Professor Xu’s workflow. “With TubeGuard, we have a significantly smaller risk of unscheduled downtime. If Siemens gives us a call today and pre-dicts that one particular tube will break within the next days, we can have a Siemens engineer come over that very evening. He can change the tube outside of our regular working hours. The next morning, we just continue our work with our patients. Nobody needs to wait.”

TubeGuard: Proactive Tube Failure PredictionSince 1984, China’s renowned Shandong Medical Imaging Research Insti-tute has been relying on Siemens for most of its medical imaging equip-ment. Its latest innovation is a new service option: TubeGuard, which pro-vides critical backup to avoid total tube breakdowns in CT scanners from the SOMATOM Defi nition family.

By Justus Krüger

Life

Justus Krüger lives in Hong Kong and Beijing. He works as a China correspondent for the Berliner Zeitung newspaper.

Professor Xu and his staff, as well as the CT scanners they are operating, are constantly working at full capacity. Based on TubeGuard’s complex algorithms and customer-specific system usage data, the tube monitoring experts perform an ongoing assessment of remaining tube life.


Topic

Gil Palcone was a little disappointed at first. Siemens Philippines – computedtomography (CT) supplier of The Medical City Hospital in Manila – was not goingto send him to Erlangen, Germany for his training course, as it did two monthsbefore, but to the new Siemens Training Center in Shanghai.“I did have doubts whether the courses in Shanghai would be as good as the ones in Germany,” says the 43-year-old biomedical engineer. His doubts, how-ever, disappeared as soon as he arrived in Shanghai. “I am 100% satisfied with the classes here,” Palcone happily de-clares. He is already hoping for an up-date of his skills in a specific SOMATOM® Definition AS+ training. The Siemens Training Center in the Chinese metropolis is part of Siemens Healthcare’s global training concept.The training, part of Siemens UPTIME Services, helps customers worldwidemaintain their expertise on the cutting

edge of medical and clinical technology,and develop it even further – regardless whether it takes place in Germany, theU.S. or China. Even minimizing dose appli-cation due to ALARA (As Low As Reason-ably Achievable), an increasingly important issue today, is part of the training program.

Global Training Concept“Our global training concept helps pro-vide the same high standards in all of our training facilities,” says Thomas Weller, General Manager for Customer Services at Siemens Shanghai Medical Equipment.The courses help Siemens customers deepen their understanding of extremely sophisticated, state-of-the-art medical equipment. That in turn empowers them to optimize workflows, avoid and detect operational errors, and fully utilize their equipment’s potential by concurrently minimizing dose to a diagnostically ideal value. This improves examination results and increases patient care and satisfac-

tion. For the healthcare providers, opti-mizing workflows also means higher system availability and a marked reduc-tion in costs.These are significant issues for the whole spectrum of Siemens Healthcare custom-ers. Equipment such as CT scanners is in such high demand, especially in large hospitals, that patients often have to endure long waits. With an in-house en-gineer educated in one of Siemens Train-ing Centers smoothing out potential fail-ures within the framework of a Shared Services agreement, the systems can be utilized more efficiently, saving time for both operators and patients.

Theory and Practice“That is an important factor,” says Weller, “especially when it comes to systemssuch as CT scanners, which are often in use nonstop from eight in the morninguntil ten in the evening.” Indeed, far from merely providing the latest theoretical

State-of-the-Art TrainingBy Justus Krüger

All three Siemens Healthcare training centers, in Shanghai, China, Cary, USA and Erlangen, Germany, offer high quality training.


Topic


“Discover. Try. Buy.” – a New Portal for Individually Expanding Clinical Capabilities For Example, syngo CT Oncology with Low Dose Spiral Exams

By Julia Kern-Stoll and Marion Meusel, Business Unit CT, Siemens Healthcare, Forchheim, Germany

The latest updated overview on Siemens Healthcare’s CT Clinical Applications is now online. On this online portal, cus-tomers can discover clinical applications via key feature descriptions, demo vid-eos and clinical image galleries. Case studies describe the experience of users in order to illustrate how these applica-tions can improve clinical routine. These new CT online pages offer comprehen-sive information – easily accessable, all in one place. One of the highlight applications is syngo CT Oncology. In the US, more than 60% of CT exams are motivated by cancer diagnosis, treatment and follow-up management. syngo CT Oncology is a comprehensive software designed to fast-track routine tumor diagnosis, stag-ing, and follow-up. It provides a range of tools specifically designed to support physicians in the detection, segmenta-tion, and evaluation of suspicious le-sions.

syngo CT Oncology in combination with low-dose CT spiral exams of the chest, abdomen, pelvis etc., includes detec-tion, diagnosis, staging and follow-up of lung nodules, colon polyps, mediastinal lesions, liver lesions and lymph node primary involvement or metastasis.On the CT web portal, case studies detail the advantages of fully automated tu-mor tracking and tumor measurement with syngo CT Oncology. Furthermore, they describe the identification of a non-Hodgkin-Lymphoma recurrence and show the enhanced diagnostic accuracy in the case of a follow-up of a pediatric patient with Lymphoma.The demo videos also explain the usage of syngo CT Oncology in case of a liver lesion evaluation. Customers can discover and try syngo CT Oncology* for a 90 day period at no cost. The free trial program is available for many more clinical applications. *Depending on system configuration.

International:

www.siemens.com/discoverct

USA only:

www.usa.siemens.com/webShop/ct

Comprehensive information on clinical CT applications, now online – all in one place.

training, the Training Centers also offer practical application, which is truly indis-pensable to provide first-class medical service. The training divides participants into four levels, depending upon their knowledge level: Basic, Advanced, Ex-pert, and Refreshment. The target groups for training include physicians, radiology technologists and radiogra-phers, as well as engineers and hospital IT administrators. Siemens not only of-fers its customers the chance to continu-ously enhance their skills, but is also fur-ther educating their own service engineers. The main participants, other than customers of Siemens Healthcare,

are Siemens Customer Service Engineers (CSEs). Combining the courses for cus-tomers and Siemens staff, UPTIME Ser-vices provides a great opportunity to ex-change valuable experience.Because providing good quality training is a top priority of Siemens, the number of participants per course is limited to twelve. This allows an intensive ex-change between trainers and partici-pants. It also helps provide everyone with plenty of opportunity to work with the systems and to get hands-on experi-ence with the equipment.“We don’t just study theory; we apply it to the systems – every day,” Palcone

says. “That way you can really absorb the knowledge.”

High-Quality TrainingAll three training centers offer the same high quality of training, and that is, in part, due to the same high level of skills and knowledge demanded of the trainers. Whether the trainers work in Shanghai, Cary, or Erlangen, the skills required of them are high, not only in technical knowl-edge, but also in the ability to teach and transmit that knowledge.

Justus Krüger is correspondent for the Berliner Zeitung in Beijing, China.

Life


Life

In January 27–30, 2010, the 6th Interna-tional Symposium for Multislice CT, will take place in Garmisch-Partenkirchen, Germany. More than 1300 participants are expected to take part in this con-gress, located in Garmisch-Partenkirchen Congress House.Since the last CT-Symposium two years ago, great steps in the technology devel-opment of computed tomography have introduced new clinical indications and relevant advancements in the diagnostic capabilities of Computed Tomography. The congress will be state-of-the-art, sci-ence-oriented and relevant for everyday practice. It includes an update-course for technical qualification for radiation protection according to German X-ray and radiation protection regulations. A “CT-basics” course will also be offered. A mul-tifarious, many-sided and interesting

program will be provided for the con-gress participants. Among topics relevant for every practical work such as Ear-Nose-Throat Imaging, Oncological Imaging or CT of the Thorax, the program will also include innovative topics such as CT perfusion of the body and head, Dual Energy body imaging, CT angiography, contrast medium tolerance, virtual colonoscopy, and cardiac CT. The sympo-sium is geared to all who are interested in CT (chief physicians, senior physicians, residents and technical staff of university and non-university hospitals) as well as established radiologists, health physicists, physicians and physicists from industry and research. The symposium is accred-ited by the Bavarian “Landesärztekammer” and the German Academy for Advanced Training in Radiology. Due to this, there will be the possibility to register for CME-

credits. (Continuing Medical Education). Also, the medical industry exhibition area might be of interest, where onsite and live information about the actual developments in CT and contrast agents can be collected.Note: speeches and discussions will be delivered in German language.

CT 2010 – The Congress

Further information on the CT 2010 web site (www.ct2010.org), where online registration is now possible.

Want to know the secrets of how to perform a super low-dose cardiac scan, or how to quantify absolute iodine con-centration of a lesion using Dual Energy?With the launch of the SOMATOM®

Definition Flash, two versions of the CT Life Card were released – CT Life Card syngo CT 2009A for the scanner and CT Life Card syngo 2009B for the syngo MultiModality Workplace (MMWP).

The great news is that the CT Life Card syngo 2009B is now installable on the syngo MMWP and the educational con-tent is available 24/7 on the console.In this edition of the Workflow Assistant, the basic principle and workflow on how to perform a cardiac scan using the Flash Spiral Cardiac mode is introduced. New, exciting dose modulation possibilities with the sequential cardiac scan are high-lighted. Additionally, detailed examina-tion workflow modules are provided for Dual Energy evaluation of kidney lesions and single solitary lung nodules, together with explanations on the enhanced syngo Dual Energy application.A CT Life Card DVD can be found in the Welcome Pack or User Documentation kits.

How to Perform a Cardiac Scan with Less than 1 mSv

6. Internationales Symposium

MEHRSCHICHT CTund Aktualisierungskurs

Fachkunde Strahlenschutz nach

RöV und StrSchV

(inkl. CT Grundkurs: Protokolle

und Anwendungen für Ärzte

und MTAs)

Kongresspräsidenten:

Prof. Dr. Dr. h.c. Maximilian Reiser

Institut für Klinische Radiologie

Klinikum der Universität München

Prof. Dr. Gary Glazer

Department of Radiology

Stanford University, USA

Kongresshaus Garmisch-Partenkirchen

27. – 30. Januar 2010

www.ct2010.orgInformation und Anmeldung: EUROKONGRESS GmbH, Schleissheimer Straße 2, D-80333 München

Tel.: +49-89-210 98 60, Fax: +49-89-210 98 698, Email: [email protected], www.eurokongress.de

Anmeldung online

www.ct2010.org

By Loke-Gie Haw, Business Unit CT, Siemens Healthcare, Forchheim, Germany

Workflow Assistant – Explanation of Flash Cardiac Spiral workflow.


Topic

The city of Valencia, with its historic and modern architecture and its thriving cultural scene was an excellent backdrop for Siemens’ SOMATOM World Summit, the 9th CT User Conference, a highly inspiring bi-annual meeting for informa-tion exchange among CT users.Much had happened in the world of CT since the previous SOMATOM World Summit in Berlin 2007, and this year’s conference put the latest developments right at the user’s fingertips. During 37

outstanding lectures, clinical experts from around the globe shared their expe-riences on the latest developments in CT.A wide spectrum of presentations and more detailed information can be re-viewed on a DVD that will bring you up-to-date on trend-setting developments in computed tomography, including applications in cardiovascular imaging, neurology, oncology and acute care. The latest low-dose imaging options and first clinical results of the SOMATOM®

Definition Flash – the new CT system that delivers best results in a split sec-ond – are outlined. Best practices and latest clinical trends from the world’s leading CT experts are included as well as advanced techniques and innovative solutions. A copy can be ordered free of charge through the following link:

Free DVD of the SOMATOM World Summit 2009 in ValenciaBy Heike Theessen, Business Unit CT, Siemens Healthcare, Forchheim, Germany

www.siemens.com/ct-infoportal

SOMATOM World Summit 2009 – a highly inspiring meeting for CT users.

How can the dose be reduced for rou-tine CT Angiography (CTA)?There are several methods to reduce pa-tient dose in order to minimize the po-tential risk. Siemens’ CARE Dose4D (au-tomatic dose modulation), for example, is one of these methods. But the user can also lower the dose himself by using 100 kV, or even 80 kV, instead of the usual 120 kV. This can result in a dose reduction of up to 50% for average and smaller sized patients. Since the purpose of a CTA is to differen-tiate the arteries clearly from adjacent tissues, and if the arteries are filled well with iodine contrast agent, the tube voltage (kV) can be reduced. A lower tube voltage results in better contrast resolution as well as lower patient dose. However the tube current (mAs) needs

to be adjusted accordingly to obtain good image quality. For the recalcula-tion of the new tube current the follow-ing formulas should be used:CTA with focus on vessels: mAs (120kV) x 1.3 = mAs (100kV) – (Potential dose reduction up to 25%).CTA with focus on vessels and soft tis-sue: mAs (120kV) x 1.5 = mAs (100kV) - (Potential dose reduction up to 10%).CTA for very small patients, e.g. chil-dren: mAs (120kV) x 2 = mAs (80kV) - (Potential dose reduction up to 50%).

Frequently Asked Questions

SOMATOM Definition Flash Coronary CTA: calcified LAD and RCA, scanned with

low dose of less than 1 mSv. Courtesy of Erasmus Medical Center,

University Hospital Rotterdam, Netherlands

By Ivo Driesser, Business Unit CT, Siemens Healthcare, Forchheim, Germany


Life

Clinical Workshops 2010As a cooperation partner of many renowned hospitals, Siemens Healthcare offers continuing CT training programs.

Workshop Title Location Dates Course Course language director

Workshop on Diagnosis of Paris, France March 25–26 2010 English Jean Francois Paul, MDCongenital Heart in CT

Clinical Workshop on Cardiac CT Munich, Germany March 24–26 2010 English PD Konstantin Nikolaou, MD July 07– 09 2010 Prof. Christoph Becker, MD Dec. 15–17 2010 Alexander Becker, MD

Clinical CTA Interpretation Course Erlangen, Germany March 18–19 2010 English Prof. Stephan Achenbach, MD Jan. 21-22 2010

Clinical Training Course Kuching, Malaysia March 5–6 2010 English Prof. Sim Kui Hian, MDon Cardiac CT June 26–27 2010 Ong Tiong Kiam, MD Oct. 30–31 2010

Virtual CT Colonography Berlin, Germany Feb. 26–27 2010 German Prof. Bernd Lünstedt, MD June 11–12 2010 Nov. 05–06 2010

Dual Energy Workshop Forchheim, Germany April 16 –17 2010 English PD Thorsten Johnson, MD Sept. 10 –11 2010

ESGAR CT Colonography Amsterdam, April 21–22 2010 English Prof. Jaap Stoker, MDWorkshops The Netherlands Lisbon (Cascais), Sept. 23–24 2010 English Prof. Filippe Caseiro-Alves, MD Portugal

Dubai CT-Workshop Dubai, UAE Feb. 14 –15 2010 English Prof. Christoph Becker, MD Alexander Becker, MD

Hands-on Workshops Vienna, Austria March 4– 8 2010 English n.a.during ECR 2010

In addition, you can always fi nd the latest CT courses offered by Siemens Healthcare at www.siemens.com/SOMATOMEducate

CT is increasingly becoming an imaging technique for congenital heart defects. When echocardiography cannot provide the diagnosis, MSCT offers advantages in comparison with MRI and angiography. The two most challenging aspects of CT when examining children, are radia-tion dose and scan time which makes an-esthesia often necessary.

By Heike Theessen, Business Unit CT, Siemens Healthcare, Forchheim, Germany

With the introduction of the latest gener-ation of Dual Source CT, the SOMATOM® Definition Flash, big steps have been made, to overcome these challenges. Thus, CT becomes an even more attrac-tive technique to use for the diagnosis of congenital heart defects. Jean-Francois Paul, MD, from Centre Chirurgical Marie Lannelongue in Paris, France, who has

New Workshop Format: Diagnosis of Congenital Heart Defects

www.siemens.com/life-courses

significant experience in cardio-vascular CT, will hold a workshop on the diagnosis of congenital heart defects. The 2-day workshop takes place at the hospital on 25th and 26th March 2010 and involves an anatomic study of specimen and the possi-bility to follow interventional procedures.


Life

Upcoming Events & Congresses

Title Location Short Description Date Contact

RSNA Chicago, USA Annual Meeting of Nov. 29–Dec. 04, 2009 www.rsna.org Radiological Society of North America

Moscow Healthcare Moscow, Russia International Dec. 07–11, 2009 www.zdravo-expo.ru/en exhibition

Arab Health Dubai, UAE Exhibition and Jan. 25–28, 2010 www.arabhealthonline.com scientific congress

6th International Garmisch- Scientific Talks Jan. 27–30, 2010 www.ct2010.orgSymposium Partenkirchen, and Lecturesof Multislice CT Germany

26th Annual Computed Orlando, USA CME Course Feb. 11–14, 2010 www.hopkinscme.eduTomography 2010: The Cutting Edge

3. Deutsche Kardio- Stuttgart, Scientific talks Feb. 25–27, 2010 www.kardiodiagnostik.dediagnostik-Tage Germany and lectures

ECR Vienna, Austria Exhibition and March 04–08, 2010 www.ecr.org scientific congress

ACC Atlanta, Exhibition and March 14–16, 2010 http://essacc10.acc.org/ Georgia, USA scientific congress index.html

AOCR Taipei, Taiwan 13th Asian Oceanian March 20–23, 2010 http://www.aocr2010.org Congress of Radiology

Deutsche Gesellschaft Mannheim, 76th annual meeting April 08–10, 2010 www.dgk.orgfür Kardiologie Germany

ECI0 2010 Florence, Italy Global Embolization April 21–24, 2010 http://www.ecio2010.org Symposium and Technologies

JRC Yokohama, Exhibition (ITEM) and April 08–11, 2010 www.j-rc.org Japan scientific congress

DRK Berlin, Germany National scientific May 12–15, 2010 www.drg.de congress

12th International San Francisco, Stanford CME course May 18–21, 2010 http://radiologycme.stanford.eduSymposium on USA and exhibitionMultidetector-Row CT


Topic

Siemens Healthcare – Customer MagazinesOur customer magazine family offers the latest information and background for every healthcare fi eld. From the hospital director to the radiological assistant – here, you can quickly fi nd information relevant to your needs.

For current and prior issues and to order the magazines, please visit www.siemens.com/healthcare-magazine

Medical SolutionsInnovation and trends in healthcare. The magazine, published three times a year, is designed especially for members of the hospital management, administration per-sonnel, and heads of medical departments.

AXIOM InnovationsEverything from the worlds of interventional radiology, cardiology, fluoroscopy, and radiography. This semi-annual magazine is primar-ily designed for physicians, physicists, researchers, and medical technical personnel.

MAGNETOM FlashEverything from the world of magnetic resonance imaging. The magazine presents case reports, technology, product news, and how-to’s. It is primarily designed for physicians, physicists, and medical technical personnel.

SOMATOM SessionsEverything from the world of computed tomography. With its innovations, clinical applications, and visions, this semiannual magazine is primarily designed for physicians, physicists, researchers, and medical technical personnel.

PerspectivesEverything from the world of clinical diagnostics. This semi-annual publication pro-vides clinical labs with diag-nostic trends, technical inno-vations, and case studies. It is primarily designed for laboratorians, clinicians and medical technical personnel.

NewsOur latest topics such as product news, reference stories, reports, and general interest topics are always available at www.siemens.com/healthcare-news

SOM

AT

OM

Ses

sio

ns

RSN

A-E

dit

ion

No

vem

be

r 2

009

25

SUBSCRIBE NOW!

– and get your free copy of future

SOMATOM Sessions! Interesting information

from the world of computed tomography – gratis

to your desk. Send us this postcard, or subscribe

online at www.siemens.com/ct-news

SOM

AT

OM

Sess

ion

sPatient‘s safety domi-nates physicians work. In Computed Tomo-graphy that means achieving highest image quality with the absolute minimum dose possible. Over the years, Siemens has been highly creative in integrating dose-reduction innovations into their CT-scanners.

Siem

ens

AG

Med

ical

Sol

uti

ons

CC

CB

Hen

kest

raße

127

910

52 E

rlan

gen

Ger

man

yOn account of certain regional limitations of sales rights and service availability, we cannot guarantee that all products included in this brochure are available through the Siemens sales organization worldwide. Availability and packaging may vary by country and is subject to change without prior notice. Some/All of the features and products described herein may not be available in the United States.

The information in this document contains general technical descriptions of specifications and options as well as standard and optional features which do not always have to be present in individual cases.

Siemens reserves the right to modify the design, packaging, specifications and options described herein without prior notice. Please contact your local Siemens sales representative for the most current information.

Note: Any technical data contained in this document may vary within defined tolerances. Original images always lose a certain amount of detail when reproduced.

www.siemens.com/healthcare-magazine

Global Business Unit

Siemens AGMedical SolutionsComputed TomographySiemensstraße 1DE-91301 ForchheimGermanyPhone: +49 9191 18 - 0www.siemens.com/healthcare

Local Contact Information

Asia/Pacific:Siemens Medical SolutionsAsia Pacific HeadquartersThe Siemens Center60 MacPherson RoadSingapore 348615Phone: +65 9622 - 2026www.siemens.com/healthcare

Canada:Siemens Canada LimitedMedical Solutions2185 Derry Road WestMississauga ON L5N 7A6CanadaPhone: +1 905 819 - 5800www.siemens.com/healthcare

Europe/Africa/Middle East:Siemens AGMedical SolutionsHenkestraße 127D-91052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Latin America:Siemens S.A.Medical SolutionsAvenida de Pte. Julio A. Roca No 516, Piso 7C1067ABN Buenos Aires ArgentinaPhone: +54 11 4340 - 8400www.siemens.com/healthcare

USA:Siemens Medical Solutions U.S.A., Inc.51 Valley Stream ParkwayMalvern, PA 19355-1406USAPhone: +1-888-826 - 9702www.siemens.com/healthcare

Global SiemensHealthcare Headquarters

Siemens AGHealthcare SectorHenkestraße 12791052 ErlangenGermanyPhone: +49 9131 84 - 0www.siemens.com/healthcare

Global Siemens Headquarters

Siemens AGWittelsbacherplatz 280333 MuenchenGermany

Order No. A91CT-00973-41M1-7600 | Printed in Germany | CC CT 00973 ZS 1109/41.5 | © 11.2009, Siemens AG

The Difference in Computed Tomography

SOMATOM Sessions

25

Issue Number 25/November 2009RSNA-Edition I November 29th – December 04th, 2009

Cover Story Mission Possible: Reducing Radiation Dose in CTPage 6

News International CT Image Contest – Highest Image Quality at Lowest DosePage 17

Business Lowest Dose Motivates PurchasePage 24

Clinical OutcomesDose Neutral Dual Energy Carotid CTA with SOMATOM Defi nition FlashPage 34

Science Analysis of DNA Double-Strand Breaks Promises New View of Dosimetry in CTPage 52

mmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmmSSSSSSv dddddddddddddoooooooooooooooooooosssssssssssssssssssseeee


Editorial

“For us and our customers, patient safety means achieving highest quality images with the absolute minimum dose possible.”Sami Atiya, PhD, Chief Executive Officer, Business Unit Computed Tomography, Siemens Healthcare, Forchheim, Germany

Cover Page: No breath hold and no anesthesia was necessary in this pediatric imaging with 0.37s scan time, by using only 1 mSv. Courtesy of University of Erlangen-Nuremberg, Erlangen, Germany

“Reducing radiation dose has always been a concern for Siemens.”

Thomas Flohr, PhD, Director of CT Physics and Applications, Siemens Healthcare, Germany

Yes, I consen

t to the above in

formation

being u

sed for fu

ture con

tact regarding produ

ct updates an

d other

importan

t new

s from Siem

ens.

Please print clearly!

Sub

scriptio

n

un

subscribe from

info service

Stay up

to d

ate with

the latest in

form

ation

Reg

ister for:

the m

onth

ly health

care e-new

sletter

Please enter yo

ur b

usin

ess add

ress

Institu

tion

Departm

ent

Fun

ction

Title

Nam

e

Street

Postal Code

City

State

Cou

ntry

E-mail

Please inclu

de m

e in yo

ur m

ailing

list for th

e fo

llow

ing

Siemen

s Health

care custo

mer m

agazin

e(s):

Medical Solu

tions

MA

GN

ETOM

Flash

SOM

ATOM

Sessions

AX

IOM

Inn

ovations

Responsible for Contents: André Hartung

Editorial Board: Andreas Blaha Andreas Fischer Thomas Flohr, PhD Klaudija Ivkovic Axel Lorz Jens Scharnagl Stefan TheesenHeiko Tuttas Alexander Zimmermann

Authors of this Issue:S. Alibek, MD, Institute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany

H. Alkadhi, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

T. Asami, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

F. Bamberg, MD, MPH, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

Note in accordance with § 33 Para.1 of the German Federal Data Protection Law: Despatch is made using an address file which is maintained with the aid of an automated data processing system.SOMATOM Sessions with a total circulation of 35,000 copies is sent free of charge to Siemens Computed Tomography customers, qualified physicians and radiology departments throughout the world. It includes reports in the English language on Computed Tomography: diagnostic and therapeutic methods and their appli-cation as well as results and experience gained with corresponding systems and solutions. It introduces from case to case new principles and procedures and discusses their clinical potential.The statements and views of the authors in the individual contributions do not necessarily reflect the opinion of the publisher.The information presented in these articles and case reports is for illustration only and is not intended to be relied upon by the reader for instruction as to the prac-tice of medicine. Any health care practitioner reading this information is reminded that they must use their own learning, training and expertise in dealing with their individual patients. This material does not substitute for that duty and is not in-tended by Siemens Medical Solutions to be used for any purpose in that regard.

A. Becker, MD, Department of Medicine, Cardiology Division, University of Munich, Campus Großhadern

F.Civaia, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

G. Feuchtner, MD, Institute of Diagnostic Radiol-ogy, University Hospital Zurich, Zurich, Switzerland

E. Hendrich, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

K. Kichikawa, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan

S. Kitano, MD, Department of Radiology, Nara Medical University, Nara, Japan

M. Kuefner, MD, Institute of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany

T. Lee, MD, Department of Radiology, Bringham and Women’s Hospital, Boston, USA

M. Lell, MD, Institute of Radiology, University of Erlangen-Nuremberg, Erlangen, Germany

S. Leschka, MD, Institute of Diagnostic Radiology, University Hospital Zurich, Zurich, Switzerland

S. Martinoff, MD, Department of Radiology and Nuclear Medicine, German Heart Center, Munich, Germany

T. Morita, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

S. Mukundan Jr., MD, PhD, Department of Radi-ology, Bringham and Women’s Hospital, Boston, USA

T. Murakami, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

K. Nikolaou, MD, Department of Clinical Radiology, University of Munich, Campus Großhadern, Munich, Germany

P. Rossi, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

S. Rusek, MD, Department of Cardiology, Centre Cardio-Thoracique de Monaco, Monaco

B. Ruzsics, MD, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA

H. Saeki, MD, Department of Cardiovascular Internal Medicine, Saiseikai Matsuyama Hospital, Matsuyama, Japan

J. Schoepf, MD, Department of Radiology and Radiological Science, Medical University of South Carolina, Charleston, SC, USA

A. Sodickson, MD, PhD, Department of Radiolo-gy, Bringham and Women’s Hospital, Boston, USA

G. Staatz, MD, Section Pediatric Radiology, Insti-tute of Radiology, Friedrich-Alexander University Erlangen-Nuremberg, Erlangen, Germany

J. Takahama, MD, Department of Radiology, Nara Medical University, Nara, Japan

H. Tanaka, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

T. Taoka, MD, PhD, Department of Radiology, Nara Medical University, Nara, Japan

K. Watanabe, MD, Department of Cardiovascular Internal Medicine, Saiseikai Matsuyama Hospital, Matsuyama, Japan

M. Yamamoto, MD, Department of Radiology, Saiseikai Matsuyama Hospital, Matsuyama, Japan

Catherine Carrington, freelance author, Tony DeLisa, freelance author, Amy K. Erickson, medi-cal journalist Sameh Fahmey, medical journalist, Eric Johnson, freelance technolgy and business writer, Hildegard Kaulen, PhD, freelance scien-tific journalist Oliver Klaffke, freelance scientific journalist, Justus Krüger, freelance author

Peter Aulbach; Andreas Blaha; Steven Bell; Ivo Driesser; Kerstin Fellenzer; Thomas Flohr, PhD; Jan Freund; Tanja Gassert; Loke Gie-Haw; Julia Kern-Stoll; Ernst Klotz; Carolin Knecht; Rami Kusa-ma; Marion Meusel; Jakub Mochon; Karen Sch-weizer; Peter Seitz; Heike Theessen; Stefan Wünsch; PhD; all Siemens Healthcare

Photo Credits: Stephan Sahm, Tina Ruisinger, Peter Rigaud/Shotview, Stefen Chow, Ryan Pyle, Frank Bauer

Production: Norbert Moser, Kerstin Putzer,Siemens AG, Healthcare

Design and Editorial Consulting:Independent Medien-Design, Munich, GermanyIn cooperation with Primafila AG, Zurich, Switzerland, Managing Editor: Christa Löberbau-er, Photo Editor: Susanne Nips, Layout: Claudia Diem, Mathias Frisch, All at: Widenmayerstraße 16, 80538 Munich, Germany

The drugs and doses mentioned herein are consistent with the approval labeling for uses and/or indications of the drug. The treating physician bears the sole re-sponsibility for the diagnosis and treatment of patients, including drugs and doses prescribed in connection with such use. The Operating Instructions must always be strictly followed when operating the CT System. The sources for the technical data are the corresponding data sheets. Results may vary.Partial reproduction in printed form of individual contributions is permitted, provid-ed the customary bibliographical data such as author’s name and title of the con-tribution as well as year, issue number and pages of SOMATOM Sessions are named, but the editors request that two copies be sent to them. The written consent of the authors and publisher is required for the complete reprinting of an article.We welcome your questions and comments about the editorial content of SOMATOM Sessions. Manuscripts as well as suggestions, proposals and informa-tion are always welcome; they are carefully examined and submitted to the edito-rial board for attention. SOMATOM Sessions is not responsible for loss, damage, or any other injury to unsolicited manuscripts or other materials. We reserve the right to edit for clarity, accuracy, and space. Include your name, address, and phone number and send to the editors, address above.

SOMATOM Sessions – IMPRINT© 2009 by Siemens AG, Berlin and MunichAll Rights Reserved

Publisher:Siemens AGHealthcare SectorBusiness Unit Computed TomographySiemensstraße 1, 91301 Forchheim, Germany

Monika Demuth, PhD ([email protected])

Stefan Wünsch, PhD([email protected])


Imprint

Chief Editors:

SOMATOM Sessions is also available on the internet: www.siemens.com/SOMATOMWorld

Documents

Somatom sessions 25