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Mathias Prokop, MD: Cardiac CT- what comes after the

slice race?

May 16, 2008- 9:10

Stanford Radiology 10th Annual Multidetector CT

Symposium

Cardiac CTCardiac CT – – what comes after the slice race?what comes after the slice race? A critical analysis of where we stand and what we need A critical analysis of where we stand and what we need

10th Annual International Symposium on Multidetector-Row CT

Las Vegas, May 13Las Vegas, May 13--16, 200816, 2008

Mathias Prokop, MD PDMathias Prokop, MD PDUniversity Medical Center UtrechtUniversity Medical Center UtrechtThe NetherlandsThe Netherlands

Member, advisory boardMember, advisory board

Philips Medical SystemsPhilips Medical Systems

CT Performance

n c e

100.0

1000.0

Performance = coverage per second / eff. slice thickness

64-slice

P e r f o r m a

0.1

1.0

10.0

1985 1990 1995 2000 2005

Conventional

Spiral

Dual-slice 4-slice

8-slice16-slice

2010

The Slice Race

MDCT Scanner Generations

4-slice CT

1998

Fast scans

Spiral CT: 6cm in 30s

high resolution

for most

organ systems

4 x1 mm4 x1 mm 25 s scan25 s scan

16-sl ice CT

2002

Fast scans +

for all organ

systems

16 x0.75 mm16 x0.75 mm 8 s scan8 s scan

16x0.75 mm

13 s scan duration

Faster Scans ?

Scanning may become too fast

r tca or :

• Large aneurysms

• Slow flow

• Peripheral runoff

• Decreased &

inhomogenous contrast




slice race?

May 16, 2008- 9:10


Symposium

64-sl ice CT

2005

Fast scans +high resolution +

for all organ

systems

Gated

thoracoabdominal

CTA

4-slice CT

1998

Coronary CTA

4 x1 mm4 x1 mm 40 s scan40 s scan

16-sl ice CT

2002

Fast scans +

for all organ

systems

16 x0.75 mm16 x0.75 mm 20s scan20s scan

CATSCAN Trial - Qualifier

became feasible

64-sl ice CT

2005

RCARCAstentstent

LAD Coronary CTA

became practicable

Multi-detector CT

Scanner Generations

1st gen. 2nd gen. 3rd gen. 4th gen.

1998 2000-02 2004-05 2006-08

4 rows 16 rows64 rows

320 rows

32 rows

+ z-FFS

64 rows

+ new detector

rows + z-

+ dual source

128 rows + z-FFS

Beyond the Slice Race

4th Generation Scanners




slice race?

May 16, 2008- 9:10


Symposium

Image quality• Spatial resolution

• Ima e noise


Important Scanner Features

• Artifacts / temporal resolution

Scan speed

Coverage

Radiation dose / prospective triggering

Multi-detector CT

4th Generation

Dual source

• Two x-ray tubes

Siemens

Somatom Definition

• Air-bearing gantry

Wide detector

• 8-16 cm

ps

Toshiba Aquilion One

Philips iCT

New detector / iterative recon.

• Higher resolution / less noise

GE CT750 HD


Siemens

Somatom Definition

Dual source

New tube with z-FFS

Temporal resolution

Dual energy

85 ms85 ms


Toshiba

Aquilion One

Wider detector (320x0.5mm = 16cm)

Cone beam recon + scatter correction

Full organ coverage

Dynamic scanning

Courtesy P. Rogalla, Berlin


Philips

iCT

Wider detector (128x0.625mm = 8cm)

Air-bearing gantry (270ms rotation)

New tube with z-flying focal spot

2D scatter grid

Compromise resolution / speed / coverage


GE

CT750 HD

New detector material and design

Iterative image reconstruction

Spatial resolution / noise

Dual energy




slice race?

May 16, 2008- 9:10


Symposium

Detector Slices Width

GE CT750 HD 64x0.625 64 4 cm*


Detectors

Philips iCT 128x0.625 256 8 cm

Siemens Definition 32x0.6 64 1.9 cm

AS+ 64x0.6 128 3.8 cm

Toshiba One 320x0.5 320 16 cm

* New detector material

Tubes Rotat. pro. retro.ms ms ms


Temporal Resolution

-

Philips iCT 1 270 140 40-140

Siemens Definition 2 330 85 40-85

AS+ 1 300 150 50-150

Toshiba One 1 350 180 50-180

width pro. retro.

GE CT750 HD 4 cm 7 6


Number of Heartbeats to Scan the Heart

Philips iCT 8 cm 3 3

Siemens Definition 1.9 cm 8 7

AS+ 3.8 cm 4 4

Toshiba One 16 cm 1 1-3

14cm scan length

Prospective or Retrospective ?

320-slice CT

Retrospective, 2 heartbeats

Heart rate: 58 bpm

Heart rate: 92 bpm

Courtesy of P. Rogalla, Charite, Berlin, Germany

Prospective, 1 heartbeat


Functional CT

Morphology• Coronaries

• Heart + vessels


CT Applications

• Standard for all organ

systems

16-slice sufficient

Perfusion• Myocardium

Motion• Cardiac function

• Joint motion

• Breathing

• Brain, lung

• Tumors

All other indications profit from 4th generation




slice race?

May 16, 2008- 9:10


Symposium

CT Perfusion

Vendor Approaches

• Spiral / shuttle mode:

bidirectional table movement

(Siemens / GE)

• Wide detectors

(Philips / Toshiba)

• Jog mode - switch between two positions

(Philips)

CT Perfusion

Shuttle Mode

Advantages:• Larger coverage

• Detector size not limitin

Courtesy of University Erlangen / Erlangen, Germany

Disadvantages:

• Patients moves

• Limited temporal

resolution

• Cardiac difficult

CT Perfusion

Stationary Mode

Advantages:

• Patients stable

• Hi h tem oral resolution

Courtesy of P. Rogalla, Charite, Berlin

• Cardiac possible

Disadvantages:

• Coverage limited by

detector size

Dual Energy

Vendor Approaches

Dual source

Siemens

Ra id kV switchin

GE

Split Detector

Philips

Klinikum Dortmund

Dual source technology

140kVp / 80 kVp

Dual Energy

Do we need it ?

Potential Applications:

• Stone differentiation

• Virtual recontrast ima es

Proven application

• Automated bone removal

• Iodine maps

Myocardial perfusion

Lung perfusion

Tumor enhancement

Low kVp imaging

may be an

alternative

Summary




slice race?

May 16, 2008- 9:10


Symposium

MDCT Implementation

Summary

4th Generation Scanners• Mature technology for body imaging (=64-slice)

• Decent technolo for erfusion

• Advanced technology for cardiac

• Best cardiac scanners

• Perfusion CT still very radiation intense,

few proven indications