Volume 33, Issue 6, June 2006
Index of content:
- Imaging Continuing Education Course: Valencia A
- CE: Medical Imaging Informatics ‐ I
MO‐A‐ValA‐01: The Role of the Physicist in the Planning and Design of Digital Image Management Systems (PACS)33(2006); http://dx.doi.org/10.1118/1.2241389View Description Hide Description
The classically trained medical physicist strives to yield maximum diagnosticinformation from an exam with minimal impact on patient health (i.e. by minimizing dose). This simple objective means that in practice the physicist must: become expert on following the latest technological developments across modalities to assist in equipment purchases, monitor and oversee the imaging protocols used at an institution, and monitor the equipment performance over its lifetime.
As the department transitions to filmless radiology, the mission remains the same, but the scope of implementation increases. The DICOM services that an imager supports are analogous to the filming options supported of yesteryear. The H&D curve of film days maps to the DQE and JND of today's detectors and displays. Quality Control encompasses not only median film density of a laser camera and MTF of a CT, but how those image properties propagate from acquisition to final display device. The key point to realize is the medical physicist is uniquely empowered to have a holistic systems view of the imagers, PACS, RIS and the needs to QC the entire chain.
In this lecture, we will discuss the value add that the medical physicist provides due to the unique collection of training and skills we possess.
1. Compare and contrast the classic role of a medical physicist in the film based department verses the filmless radiology department.
2. Identify the areas of technology and practice where the Medical Physicist adds value.
3. Case studies of cost savings made possible by the practice knowledge that a medical physicist brings to the table that IT staff may not have.
- CE: Fluoroscopy Physics and Technology ‐ I
33(2006); http://dx.doi.org/10.1118/1.2241396View Description Hide Description
- CE: Medical Imaging Informatics ‐ II
33(2006); http://dx.doi.org/10.1118/1.2241481View Description Hide Description
The DICOM (Digital Imaging and Communications in Medicine) standard has allowed for tremendous changes to occur in the workflow of a modern radiology department. Prior to DICOM, radiological images were generated, transmitted, and stored in proprietary formats by imaging vendors. DICOM provides a standard to define objects such as images and services that may be performed upon those objects. As with any disruptive technology, it has solved some problems and created a whole host of new issues. Some of these issues are being addressed within the DICOM standard while others have taken on a new life under the auspices of IHE (Integrating the Healthcare Enterprise). IHE is an initiative by healthcare professionals and industry to improve the way computer systems in healthcare share information.
This lecture is intended to provide an overview of the DICOM “language” and look at some current DICOM issues at our institution.
1. Review the history of the DICOM standard and understand its origins and goals.
2. Understand the language of DICOM objects and services.
3. Understand the possible sources of DICOM issues.
4. Learn of available online resources for additional information.
- CE: Flouroscopy Physics and Technology ‐ II
33(2006); http://dx.doi.org/10.1118/1.2241488View Description Hide Description
The modern digital fluoroscopic imagingsystem has evolved to levels of complexity and automation that, when properly applied, can provide enhanced clinical performance and flexibility over a wide range of clinical applications in a user‐friendly manner. However, achieving maximum performance from such complex systems may be best achieved through cooperative efforts between manufacturers and clinical users, in which the well‐informed clinical team can utilize the degrees of freedom available in these systems to achieve the best clinical results for each medical application of interest. The medical physicist plays an important role in this process as the person who understands the relationships between physical imaging parameters, dose, and clinical imaging performance. Therefore, an understanding of system architectures, design philosophies, image processing capabilities, and degrees of freedom in procedure programming allow the medical physicist to play a more effective role. To this end, an overview of modern digital fluoroscopic imagingsystem will be presented, with particular attention given to the range of fluoroscopic and record imaging modes provided, automatic exposure control systems, common image processing algorithms, and procedure protocol selections. Recommendations for minimizing pitfalls in equipment testing will also be presented, along with some of the unique considerations for flat panel detectors versus image intensifier‐based imagingsystems.
Research sponsored by GE Healthcare.
1. Understand the architecture of modern fluoroscopic systems, including major image and data communication pathways, control systems, and image processing from acquisition to display.
2. Gain familiarity with the flexibility in control and processing afforded by new technologies and architectures, and how manufacturers use these.
3. Be aware of the various fluoroscopic imaging modes and the related image quality and dose considerations, including dose monitoring and reporting.
4. Understand common image processing techniques, such as edge enhancement, multiband filtering, and temporal filtering, and their impact on image quality.
5. Recognize the unique aspects of Digital Flat Panel Detectors and the related implications for fluoroscopic system behavior and performance.
6. Be able to identify the types of automation implemented in systems, and know how to avoid related pitfalls in testing.
7. Recognize the various procedure protocol programming capabilities available, and how they may be customized to meet clinical objectives.
- CE: Medical Imaging Informatics ‐ III
33(2006); http://dx.doi.org/10.1118/1.2241665View Description Hide Description
As departments make the transition from screen/film imaging to soft‐copy interpretation, the emphasis of the quality control program must shift from controlling the quality and consistency of the images on film to controlling the quality and consistency of the image on the display device. A fundamental feature of this new QC process is the assessment of the performance of the display device itself. This presentation will cover the performance characteristics of CRT and LCD displays and quality assurance and assessment techniques for primary display systems. The information given reflects the recommendations of the American College of Radiology (ACR) as outlined in their Technical Standard for Teleradiology (Rev. 2002) and the American Association of Physicists in Medicine (AAPM) in On‐line Report #3 (OR‐3), the report of Task Group 18 (TG18), entitled Assessment of Display Performance for Medical Imaging Systems. The presentation will introduce the performance requirements of the ACR and AAPM for primary displays and will provide instructions for performing display assessment based on TG18 methodology. Recommendations for the instrumentation necessary to perform these tasks will also be made. As a summary, important characteristics of a display QC program will be outlined.
1. Understand the technology behind CRT and LCDdisplay devices and how they affect display performance.
2. Gain familiarity with the information contained in OR‐3 and the standards for display performance and QC in the ACR standard for teleradiology. Gain familiarity with the procedural details involved with evaluation of primary diagnostic display devices according to the methods outlined in the pending TG18 task group report.
3. Be able to establish and support an on‐going primary display QC program in a PACS‐based clinical environment.
Display Performance Requirements
Pocket Telescope (30x – 50x)
Magnifying Glass (2x)
TG18 QC (General Purpose QC and Geometric distortion)
TG18 LN (Luminance response)
TG18 UNL‐10 and −80 (Luminance uniformity, Chromaticity, Dead pixel evaluation)
TG18 AFC (Noise assessment)
TG18 CX (Resolution)
TG18 VG (Veiling glare)
TG18 LPH and LPV (Dead pixel evaluation)
Max Brightness & Contrast
Luminance of the Reflected Illuminance
Reflection & Ambient Lighting
Specular reflection of illuminated background objects
Diffuse reflection effect on Lmin and contrast
Resolution (CRT only)
Geometric Distortion (CRT only)
Veiling Glare (CRT only)
Pixel Defects (LCD only)
Geometric Distortion (CRT)
Veiling Glare (CRT)
Pixel Defects (LCD only)
Monthly (CRT) / Quarterly (LCD) Tests
Evaluation of the TG18‐QC test pattern
1. Participants will be familiar with primary display performance requirements published by the ACR and the AAPM.
2. Participants will be able to perform primary display assessment according to procedures outlined in AAPM TG18 (draft).
3. Participants will be able to design and implement a robust quality control program for primary displays in a PACS environment.
4. Participants will be able to identify specific performance tests for CRT displays and for LCD displays.
- CE: Flouroscopy Physics and Technology ‐ III
33(2006); http://dx.doi.org/10.1118/1.2241672View Description Hide Description
The number of fluoroscopy‐guided interventional procedures performed continues to grow, accompanied by an increasing complexity in these clinical procedures. Technical improvement in the x‐ray imaging equipment utilized for these procedures continues at a fast pace as well, driven in part by the clinical requirements but also by the overall advance of computational technology. It remains a challenge for an interventional laboratory to ensure that its imaging equipment provides state‐of‐the‐art capabilities in a manner consistent with internal workflow and economic factors. The situation is further complicated by the fact that the replacement cycle for this equipment can be on the order of a decade ‐ an extraordinarily long time in the arena of technological advances. These factors place a high premium on careful analysis of the requirements and technical capabilities of the fluoroscopic and angiographic equipment being considered by a laboratory for purchase.
The primary factors to be addressed in the purchase of modern interventional x‐ray imaging equipment remain the same as with any imaging equipment: the type of clinical procedures for which the equipment will be utilized. Since traditional clinical boundaries continue to evolve, equipment must be flexible to perform a range of procedures throughout a patient's anatomy. The specific concerns are the combination of cardiac, peripheral vascular, and neurovascular procedures to be performed. The answer to that question will have significant implications for the size of detector,image acquisition parameters, image processing options, and the display and storage requirements. As noted, the replacement cycle is long and these systems are not easily upgraded after purchase so identification of the procedure mix is important at the outset.
Once the procedure requirement is determined, equipment can be evaluated with regard to how well it meets those requirements. Among the options related to the type of procedure are type of detector, field‐of‐view, x‐ray tube capacity, and image processing options. Functionality relevant for all types of procedures include: (i) patient exposure monitoring and exposure reduction methods; (ii) image analysis and quantification; (iii) storage capacity; (iv) options for archive and display. In addition, local factors such as service and maintenance must also be considered.
1. Understand the relationship between clinical procedure requirements and the corresponding capabilities of interventional fluoroscopy equipment.
2. Understand the range of options available in fluoroscopy and angiography x‐ray systems.
3. Be able to assess and compare different imaging systems and prioritize local factors important for purchase decisions.
- CE: Medical Imaging Informatics ‐ IV
33(2006); http://dx.doi.org/10.1118/1.2241823View Description Hide Description
There exists today a vacuum in the knowledge to transform medicine with information technology (informatics). Many diagnosticphysicists today get pulled into their institution's PACS implementation willingly or not and find themselves trying to provide informatics leadership. For those physicists who are interested, aiding a facility with informatics can be very rewarding. There is a strong affinity between the informatics skill set and the role of diagnostic physics in the way we bridge the worlds of science and technology with medicine. Many of the leaders of the Society of ImagingInformatics in Medicine (SIIM, formerly SCAR), are diagnosticphysicists. There is an opportunity of growth for the profession to provide leadership in the changing face of medicine. A subcommittee on ImagingInformatics has been established by the AAPM to understand this opportunity. The views expressed in this talk are my own and do not necessarily reflect the opinions of the committee.
We will try and present a roadmap for those physicists who are being called in to fill the informatics roles of their department or are interested in expanding their clinical tool set to include informatics. Most physicists trained today have a solid grounding in computer science. In addition to a good comprehension in computer science, an informaticist needs to know about systems management, systems integration, and project management.
Systems management includes the information technology principles needed to ensure smooth operations of a large IT service such as PACS. This includes availability monitoring, change management, failure mode effects analysis, problem management, performance monitoring, disaster recovery, and continuity management to name a few. A physicist should not be a PACS administrator, but instead be the person to train the PACS administrators and provide the oversight and strategy to allow the facility take advantage of information technology. This is identical to our role in working closely and training technologists in image quality. The majority of PACS administrators are at the same educational level of imaging technologists.
Systems integration is a crucial part of any IT project implemented today. The need to understand the role and value of open standards based integration such as DICOM, HL7, and IHE is critical in helping to set the vision of how the facility will interoperate with the enterprise.
Project management and good communication skills are very useful in helping to coordinate large initiatives such as PACS that requires many parties to work in concert. This typically entails take the strategy view and keeping it on track at the tactical level.
Also discussed will be how some basic informatics skills can help you do your job better as a physicist. There are open source tools available that can enable you to setup DICOM research repositories as well as help you automate some of the quality control role of the department to monitor image quality and dose. There is an immense amount of data that can be mined from DICOM data with some basic tools. Film printer and monitor calibration data can also be remotely monitored and aggregated with simple network management protocol (SNMP) agents.
In conclusion the physicist is positioned to be a technology advocate for physicians, and extending this to include informatics can be very rewarding. There could even be some benefit to recognizing informatics in the curriculum of diagnosticphysicists.
1. Understand the opportunity of imaginginformatics for medical physicists.
2. Discuss the overlap in the skill sets between informaticists and physicists.
3. Discuss the pros and cons of being involved in clinical informatics projects like PACS.
4. Discuss the benefits and problems of being a dual role diagnosticphysicist.
5. Identify additional areas a physicist should pursue to play the role of an informaticist:
• Principles of Systems Management
• Systems Interoperability and Data Integrity
• Project Management
- CE: Fluoroscopy Physics and Technology ‐ IV
33(2006); http://dx.doi.org/10.1118/1.2241831View Description Hide Description