A Practical Overview of the Clinical and Operational ... · CR IMAGE QUALITY CONSIDERATIONS • Exposure Index (EI) Ranges used at various sites • Fuji CR (S150200 for Extremities;

A Practical Overview of the Clinical and Operational Impact of Computed Radiography(CR) Implementations

Shirley Weddle, RT(R)(M), CIIP, BBA

OBJECTIVES

• Define Computed Radiography (CR) • Discuss CR vendor configurations and potential effect on clinical workflow

• Demonstrate how proper CR implementation planning and follow up affects operational and clinical effectiveness

CR (Computed Radiography)

• Generally cassette based • Can be used with existing Xray equipment regardless of age of

equipment • Digital image consists of an array of code values that represent

density information • Image storage size ranges from 8MB to 16MB (high resolution)

Missing image data Pixels too few and too large Acceptable image Images: Physics of CR / J Anthony Siebert, PhD

COMPUTED RADIOGRAPHY PROCESS (Step 1)

Record image normally produced using film screen combination by forming latent image on photostimulable phosphor imaging plate


• Identify cassette with patient & exam information and place into CR Reader.

• CR Reader opens cassette and removes imaging plate which is then transported through system


Plate is then read by a laser and emits light which is collected and converted to digital electronic signals by a photomultiplier tube


Reusable imaging plate is then erased by strong light within CR unit.

Imaging plate placed back in cassette mechanically in CR Reader

Cassette ejected and available for next exposure

CR PLANNING STAGES

• Determine objectives for CR implementation • Solve current problem • Address Clinical needs for image interpretation (i.e. annotations, manipulation tools, etc)

• Improve Workflow efficiency • Free up physical space in department

• Create a plan and timeline to meet objectives • Standalone CR with Film Output versus integration with new or

existing PACS • First CR implementation or Addon • Power and Network readiness • HIS/RIS HL7 to DICOM interface readiness for Modality Worklist

CR PLANNING STAGES

• Determine budget • Determine if new

Construction versus Remodeling planned for CR, PACS and/or other Modalities

CR PLANNING STAGES

• Designate someone at site to act as Project Manager • Contact vendors to obtain information about products • Attend seminars addressing CR • Consult with other sites who have implemented systems • Investigate compatibility between CR products and desired PACS

systems • Determine maximum networking capabilities • Understand current workflow and determine processing capacity

needed to meet departmental needs

WORKFLOW AND CLINICAL CONSIDERATIONS

• Review throughput capabilities (cassettes or images per hour) per unit. Specify cassette sizes.

• Can CR Readers or processing units be linked for improved throughput and redundancy?

• How many input and QC stations can be associated with a single reader or linked readers?

• What is vendor service and warranty policy? • Will site be trained to perform minor service? • Who removes stuck imaging plates? Site or vendor? • Available staff training

WORKFLOW AND CLINICAL CONSIDERATIONS

• Address specialty exams such as Panorex and Scoliosis • Flexibility of creating/editing Study tree • Availability of Exposure Index to determine over/under exposure

of image (not available in all products) • What speed index options are available? • QC process to include software and phantoms needed as well

as report output • Availability of reject / repeat analysis software • ? CR Mammography support in future

CR CONFIGURATION OPTIONS

• Multiple Cassette Units • Needed for higher throughput work areas when imaging plates need to be recycled quickly for reuse

• Consider unit size as well as additional service space that may be needed around unit

• Consider cassette buffer size • Can cassettes be reordered after placing in unit?

Multicassette CR units

Multicassette CR unit

Redundant Linked CR Units

Single Cassette Units for lower exam throughput

Digital Chest Unit CR Portable Unit

CR MAMMOGRAPHY

ID and QC units for CR

Panorex Imaging

Scoliosis Imaging

SERVICE CONSIDERATIONS Removing Imaging Plate

CR Implementation

• PACS/IT/Service Personnel to confirm unit ready for Applications training • HL7 interface to DICOM mapping tested • DICOM Modality Worklist on units receiving order and update information • Filtering of exams to specific areas to be configured

• DICOM Send to Printer configured • DICOM Send to PACS functional • Monitor QC complete • MPPS (if available) ready for testing

CR Implementation

• Tech Super User(s) and/or PACS Administrator to assist Applications person in creating Exam “tree” using HIS/RIS exam descriptions and corresponding exam views from Departmental Procedure Manual • If CR offers choice in speed index similar to screenfilm system (i.e. 100 for Extremities and 400 for other exams), use setting closest to current desired analog technique

• If system is comparable to only one speed index (usually 200250), recalculate exposure values/technique to create new technique chart for manual techniques

Build CR Exam Study Tree

CONVERTING TECHNICAL FACTORS FILM SCREEN TO CR

CR Implementation

• Tech Super User(s) and/or PACS Administrator to assist Applications person • Verify that needed fields appear in Modality Worklist • Determine how Downtime procedures to be handled (Exam info input and recovery)

• Determine what level of training each employee to receive • Determine where and how wrong patient and exam data are to be corrected

• Match Study Description with Views if this type of mapping available with system

Exam Mapping Using Worklist

CR TRAINING AT NEW SITES

If opening a new site, consider using full body Radiology mannequin for initial training for CR

–If mannequin not accessible, may recommend that vendor offer this as a charged service

• Applications Training for techs • Document training using Competency Checklist • Encourage techs to provide input during and after training • Explain the importance of correcting exam info before sending to PACS

• Communicate and document location of product manuals for post Applications reference (physical copy vs. electronic copy on Intranet server)

CR TRAINING

CR IMAGE QUALITY CONSIDERATIONS

• Determination of acceptable Exposure Index Range for Image Quality and Dose • Use vendor recommendations as a guideline until Radiologist approves final ranges

• Must process images using correct body part algorithm for appropriate index reading

• Communicate importance of achieving desired Exposure Index levels to techs

• Images processed with incorrect algorithms to be re processed

• Chest (Grid) 110 KVP • Barium Enema (Solid Column) 110 KVP • Barium Enema (Air Contrast) 90 KVP • Lateral Spines 8090 KVP • Portable Chest (NonGrid) 8090 KVP • Skull/Facial Bones/Sinues 80 KVP • Abdomen/Pelvis/AP Spine 80 KVP • Ribs (Above Diaphragm) 70 KVP • Extremities (Bucky) 7080 KVP • Extremities (Nonbucky) 60 KVP

SUGGESTED KVP RANGES FOR CR


• Exposure Index (EI) Ranges used at various sites • Fuji CR (S150200 for Extremities; S250300 Core Body) • Kodak CR (EI 20002100 for Extremities; EI 18001900 Core Body)

• Konica CR (EI S100400) • AGFA CR (Lgm 1.82.5) • GE DR (DEI .26.78)

• Note: AAPM initiative exists to encourage vendors to standardize Exposure Index Values

Sample Exposure Index Cheat Sheet

Used at local Dallas hospital

Unfortunately, there is still a lot of overexposure occurring using CR,

especially during early implementations, due to lack of adequate training.

.

Even though the displayed image looks good on the monitor, it can still be overexposed which can result in “burnout” of hairline fractures and subtle findings. The exposure index needs to be monitored as part of a QC program to maintain consistent image quality.

Images: Physics of CR / J Anthony Siebert, Ph.D.


• Set up Exposure Index software/ “monitoring gauges” to match desired acceptable levels • Some vendors use colors as well as “gauge” • Green within limits • Yellow – slightly outside limit, but OK • Red – outside limit Repeat

• Configure Rad Rooms so that Phototiming works with CR exposures

• Determine use of grids for specific portable/cross table procedures • Determine if wall bucky grid changes need to occur • Allowing one versus multiple exposures on one imaging plate

• OK in short term if not using PACS • Image quality can be degraded if good collimation not used • Cannot window/level individual images on PACS • Have to use only one processing algorithm when more may be needed

OTHER IMAGE QUALITY CONSIDERATIONS

• Use of individual passwords needed for HIPAA compliance and to generate accurate statistical reports for each technologist

• Reject/Repeat Analysis (monthly) • Exposure Index Report (monthly) • Audit Report (determined by site) • Imaging Plate Cleaning (weekly recommended) • Imaging Plate Erasure (daily recommended)

SECURITY AND QUALITY CONTROL

Sample Reject and Repeat Software on CR unit

Sample Reject Analysis Report

CLINICIAN ACCESS TO IMAGES POST CR IMPLEMENTATION

• Web based applications via PC • CD’s with Image viewers • Film and Paper Images

CONCLUSION

Adequate Planning and Training to facilitate the CR implementation

process offers numerous clinical and workflow benefits for the Radiologists,

Radiographers, Clinicians and Patients.

Thank you for your time.

Documents

A Practical Overview of the Clinical and Operational ... · CR IMAGE QUALITY CONSIDERATIONS • Exposure Index (EI) Ranges used at various sites • Fuji CR (S150200 for Extremities;