Teaching File Research Articles

Implementing a MIRC query interface for a database driven teaching file.

This paper describes the authors' experience with integrating an existing database-driven teaching file with the RSNA (Radiological Society of North America) Medical Imaging Resource Center (MIRC). MIRC is the product of an RSNA-sponsored initiative to enable medical institutions to share their electronic medical content (images, text, and multimedia) by creating a distributed repository accessible from the Internet. An existing database-driven teaching file, developed by the authors and used extensively by the University of California San Francisco (UCSF) Department of Radiology since 1998, was retrofitted to include an interface for handling broadcast queries initiated by a MIRC query service. These queries take place through the exchange of XML documents via HTTP. After all the storage services have responded, the results are collated by the query service and presented to the user. The teaching file and MIRC interface were developed using the 4th Dimension Relational Database Management System (RDBMS). The integration process primarily involved mapping the "MIRCdocument" schema to the teaching file's schema, translating the actual MIRC query into the internal query language of the database and extending the access control mechanisms of the teaching file to allow public access. A working implementation of the interface required only 3 days of development time, with refinements taking place over several months. Interface development was greatly aided by MIRC's use of well-established Internet standards. This project has demonstrated the feasibility of implementing a MIRC interface on an existing teaching file server.

Conversion of Teaching File Cases from Film to Digital Format

The authors' institution had decided to convert its radiology teaching files from film to digital media. This study was performed to determine the simplest method for converting the analog film images to digital images without a subsequent loss in diagnostic accuracy. Twenty chest radiographs that demonstrated interstitial lung disease were randomly selected from the departmental teaching files and matched with 20 control radiographs from healthy adults. Analog film images were converted with both a diagnostic-quality film image digitizer (digitized) and a flatbed scanner equipped with a transparency adapter (scanned). Three radiology faculty members reviewed a mixed set of corresponding analog film, digitized, and scanned images. Reviewers judged whether each image depicted interstitial lung disease, indicated their level of confidence in the diagnosis, and rated each image for quality. Image quality was assessed by each reviewer subjectively at the time of viewing the individual image, without regard to other images. A one-way analysis of variance was performed to determine whether there was a statistically significant difference in diagnostic accuracy between the three image formats. Agreement in diagnosis between corresponding images in the three different formats was evaluated for each reviewer with the McNemar test. There was no statistically significant difference in diagnostic accuracy between analog film and scanned images, but there was such a difference between these two groups and digitized images. Accuracy was 97% for analog film, 94% for scanned, and 89% for digitized images. Results of the McNemar test showed no statistically significant difference in agreement between the analog film images and the scanned images for any of the reviewers (P > .05). A high-end flatbed scanner with transparency adapter provided accurate, simple, and inexpensive conversion of analog film teaching files to digital format, with no loss of the ability to detect or diagnose subtle abnormalities such as interstitial lung disease.

Magnetic Resonance Imaging of CNS Disease: A Teaching File, 2nd ed.

Magnetic Resonance Imaging of CNS Disease: A Teaching File, 2nd ed.Franklin G. MoserAudio Available | Share

Sonographic Imaging of Maternal Complications of Pregnancy

To show the role of diagnostic sonography in delineating pathologic conditions occurring during and immediately after pregnancy. Cases illustrative of a broad range of pathologic conditions were collected primarily from personal experience in a busy ultrasound clinic serving high-and low-risk pregnancies over the past 15 years, with supplemental cases drawn from departmental teaching files. Sonography was the primary diagnostic tool, with confirmation obtained from other imaging modalities in select instances. Cases were organized on an anatomic and time-of-onset basis. For conditions occurring during pregnancy, the following anatomic areas are considered: the liver and biliary tree, urinary tract, bowel, ovary, and uterus and placenta. For postpartum complications, the following conditions are discussed: subfascial and bladder flap hematomas, retained products of conception, and ovarian vein thrombophlebitis. Although the main imaging modality in these conditions was sonography, correlation with computed tomography and magnetic resonance imaging was also made in several cases. A broad variety of conditions can affect the pregnant patient, both during and immediately after pregnancy. Sonography can show many of these disease processes, with computed tomography and magnetic resonance imaging useful selectively as supplementary tools.

Integration of a multimedia teaching and reference database in a PACS environment.

In one radiology department, a computerized authoring and editing environment was developed and integrated with the picture archiving and communication systems (PACS) for creation of image-based electronic teaching files to replace a collection of printed film images. This multimedia database and authoring environment allows physicians to create reference databases for teaching and research directly from clinical cases being reviewed on PACS diagnostic workstations. The database engine allows users to generate stand-alone CD-ROMs (compact disks, read-only memory) and World Wide Web-based teaching files. The system is fully compliant with the Digital Imaging and Communications in Medicine (DICOM) standard and supports a large number of standard multimedia image file formats. The focus of the development was on convenience and ease of use of a generic system adaptable to all users. The software was integrated on the PACS workstations to allow users to add new cases to the database at any time and anywhere in the department. A pilot system was implemented in clinical operation, with a central server and several client units.

Practical FDG Imaging. A Teaching File. 2002

D. Delbeke, W.H. Martin, J.A. Patton, and M.P. Sandler, eds. New York, NY: Springer Verlag, 2002, 398 pages, $129 After the introduction of the whole-body scan mode in the early 1990s and of the combined PET/CT scanner at the end of that decade, PET, using 18F-FDG as the principal

MyPACS.net: a Web-based teaching file authoring tool.

We sought to develop a Web service that would easily allow radiologists to create their own online teaching file cases from any Web browser. We created MyPACS, a hosted teaching file authoring tool that allows easy uploading of images and descriptive information from any computer with Web access. Radiologists may designate their cases to be public or private (viewable only by the case author), and cases may be retrieved on searching for multiple parameters.

Prostatic adenocarcinoma with urothelial (transitional cell) carcinoma features.

Prostatic adenocarcinoma and urothelial carcinoma (transitional cell carcinoma) may coexist in the prostate. However, a carcinoma with mixed features has not been recognized. Four cases, three surgical pathology cases and one autopsy case of prostatic adenocarcinoma with urothelial carcinoma features, were retrospectively found in a urological pathology teaching file maintained from 1984 to 1993. Subsequently, 181 consecutive cases of radical prostatectomy from 1994 to 1999 were reviewed, and two prostatic adenocarcinoma areas with features of urothelial carcinoma were identified. Areas with urothelial carcinoma features were identified in the intraductal component of the carcinoma in five cases and in the invasive component in three cases. The intraductal carcinoma with urothelial carcinoma areas usually merged with regions of prostatic adenocarcinoma with a papillary or cribriform pattern. All prostatic adenocarcinomas having areas with urothelial carcinoma features were of high stage, and five of six cases had ductal features. The urothelial carcinoma component displayed a positive reactivity for thrombomodulin and negative or weaker reactivity for PAP and PSA than the prostatic adenocarcinoma component in the same tumor. Excluding the case noted at autopsy, all patients died of the disease within 3 years. Urothelial carcinoma features were usually associated with ductal carcinoma of high stage. Areas of prostatic adenocarcinoma with urothelial carcinoma features should be considered histopathologically as areas of mixed carcinoma of the prostate. Prostatic adenocarcinoma with areas of urothelial carcinoma features may pose a difficult differential diagnosis problem with urothelial carcinoma, especially with small biopsies with focal weak immunoreactivity for PAP, PSA, and thrombomodulin.

Wireless local area networking for linking a PC reporting system and PACS: clinical feasibility in emergency reporting.

Although local area networks (LANs) are commonplace in hospital-based radiology departments today, wireless LANs are still relatively unknown and untried. A linked wireless reporting system was developed to improve work throughput and efficiency. It allows radiologists, physicians, and technologists to review current radiology reports and images and instantly compare them with reports and images from previous examinations. This reporting system also facilitates creation of teaching files quickly, easily, and accurately. It consists of a Digital Imaging and Communications in Medicine 3.0-based picture archiving and communication system (PACS), a diagnostic report server, and portable laptop computers. The PACS interfaces with magnetic resonance imagers, computed tomographic scanners, and computed radiography equipment. The same kind of functionality is achievable with a wireless LAN as with a wired LAN, with comparable bandwidth but with less cabling infrastructure required. This wireless system is presently incorporated into the operations of the emergency and radiology departments, with future plans calling for applications in operating rooms, outpatient departments, all hospital wards, and intensive care units. No major problems have been encountered with the system, which is in constant use and appears to be quite successful.

A simple method of capturing PACS and other radiographic images for digital teaching files or other image repositories.

We sought to develop an easy-to-use method of capturing and storing radiographic images. The method that we developed can capture any digital image-including an image from a picture archiving and communication system (PACS)-using widely available, inexpensive software. Our method is easy to learn, simple to use, and inexpensive to implement. It is adaptable in a wide range of networking environments and can capture and store images rapidly for a variety of uses. It can be used without interfering with clinical workflow at the PACS workstation.

Medical Image Resource Center 2002: an update on the RSNA's Medical Image Resource Center.

The Radiological Society of North America has launched a project called the Medical Image Resource Center (MIRC) to establish a community of Web-based libraries of imaging information, including teaching files, other educational materials, and research data. This system would enable radiologic professionals to create and publish such materials more easily and to gain more convenient access to new and existing materials. An overview of the project, a brief summary of the overall requirements and objectives, and a brief description of the progress and ongoing plans for MIRC are presented.

Relative Value of Analog and Digital Teaching Files

Rationale and Objectives This study was performed to determine if it is financially reasonable for radiology residency programs that create and maintain their own teaching files to switch from analog teaching files (ATFs) to digital teaching files (DTFs). Materials and Methods Radiology residency program directors were surveyed electronically about the monetary value and importance of conventional ATFs and DTFs. The costs for maintaining each type of file were calculated at the authors' institution. Results Surveys were sent to the program directors of all 197 accredited radiology residencies. Responses were received from 48 (24%). DTFs were scored as more important than ATFs, but the difference was not significant ( P = .22). DTFs were rated as less complete ( P = .01) but more current ( P ⪡ .001) than ATFs. DTFs included the American College of Radiology Learning File (85%), in-house productions (77%), and other commercially available products (63%). Thirty percent of respondents had a DTF integrated into a picture archiving and communication system, and 28% reported having a technician dedicated to the teaching file. Program directors ascribed total median dollar values of $250 and $3,000 per year to their ATFs and DTFs, respectively. The annual costs at the authors' institution were much higher than these ascribed values: $44,720 ($91 per case) for maintaining a DTF produced in house and $24,601 ($50 per case) for maintaining an ATF, excluding physician time. Conclusion Program directors are more willing to pay for a DTF than an ATF. For both, the costs of maintenance are great and the relative monetary value is low.

Visitors and content preferences on an educational web site dedicated to clinical body computed tomography: results of a 2001 audit and online survey.

To ascertain demographic characteristics and content preferences of visitors to an educational Web site dedicated to clinical body computed tomography (CT). Such information could help determine whether the resource is attaining its educational goals. During February 2001, a commercial Internet service measured the number and average length of visits to the site, the domain names of the visitors, and the content most frequently requested. During the same month, a nine-question self-administered user survey was posted on the site's main page. The service reported 19,013 visits during which 98,685 pages of content were viewed. Of the total number of users to visit, 37.9% were from domains outside North America. Helical CT scanning protocols, teaching atlases, CT teaching files, and medical illustrations were the most frequently requested content. Of the 687 visitors responding to the survey, 51.5% were radiologists and 33.5% were radiological technologists. Radiologists and radiological technologists are the principal visitors to the site. These users prefer to view helical CT scanning protocols and the Web site's core educational material.

Projected Digital Radiologic Images for Teaching: Balance of Image Quality with Data Size Constraints

Rationale and Objectives The authors performed this study to determine, in the context of a teaching presentation with slides, the information content needed in a digitized radiologic image for it to be equivalent in quality to an analog image. Materials and Methods Eleven sets of radiologic images were obtained from a teaching file collection and digitized. The images were scanned at high resolution and saved as image files. The information content of each image was then halved repeatedly with repeat sampling of the image. This procedure was repeated nine times to yield a total of 10 images with an information content that ranged from very low (32 kB) to high (12 MB). Each of these image files was made into a 35-mm slide by using a digital slide maker. The original radiographs were subsequently made into slides by using conventional photographic methods. Care was taken to make the images identical in every respect except digitization and information content. The slides were shown to radiologists, who filled out questionnaires to rate image quality. Results Digitized slides that contain an average of 416 kB of data (the equivalent of a 750 × 570-pixel matrix with 8-bit gray levels) were equivalent to analog images for 90% of viewers. At 830 kB (1,060 × 800-pixel matrix with 8-bit gray levels), 100% of viewers found no difference between digitized and analog images. Conclusion Digital images become indistinguishable from analog images if a sufficient amount of information is retained in the digital image. There is a defined relationship between the perception of quality and the information content of a digital image.

Hypointense thrombus on T2-weighted MR imaging: a potential pitfall in the diagnosis of dural sinus thrombosis

Purpose: To determine the frequency of hypointense appearance of dural sinus thrombosis on T2-weighted images, which may mimic a normal flow void, and when possible correlate with appearance on T1-weighted images. Methods and Materials: Retrospective review of radiology files showed 51 patients with a discharge diagnosis of dural sinus thrombosis who underwent MR imaging during the period 1986–1998. These images were reviewed by an experienced neuroradiologist for appearance on T2-weighted images. This process yielded five cases in which a hypointense appearance on this pulse sequence simulated a normal flow void. An additional two cases were added from the teaching files of two other institutions giving a total of seven cases (13% of studies). The resulting study population consisted of five women and two men (mean age 27.1 years). T1 weighted images were available in five patients. In two patients MR venography was available, but not T1-weighted images. The diagnosis of dural sinus thrombosis was based solely on absence of flow void on T1-weighted images in one case, solely on absence of flow void on MR venography in two cases and absence of flow void on T1-weighted images in conjunction with MR venography or gradient echo findings in 4 patients. All images were obtained on a 1.5 T magnet (GE Medical Systems; Milwaukee, Wisconsin). Results: In all patients hypointense signal of thrombus was isointense with normal flow voids in other dural sinuses on T2-weighted images. In all cases in which T1-weighted images were available, the signal intensity of thrombus was isointense to gray matter. Conclusion: Hypointense appearance of thrombus on T2-weighted images is a potential pitfall in the MR diagnosis of dural sinus thrombosis. Because thrombus in this stage of evolution appears isointense to gray matter on T1-weighted images, careful attention must be paid to other sequences to avoid this pitfall.

Development of a teaching file by using a DICOM database.

A teaching file of Digital Imaging and Communications in Medicine (DICOM) images was developed. Selected computed tomographic, magnetic resonance, angiographic, nuclear medicine, and ultrasonographic images were transferred to a personal computer (PC) with a 75-GB hard drive. The database created from the DICOM header information was modified to include American College of Radiology (ACR) Learning File categories. Database modification allowed cases to be searched by diagnosis, by findings, and by patient age, sex, and demographics. Technologists inputted ACR codes into the DICOM headers before the images were acquired, thereby reducing database maintenance time. Images were manipulated and reviewed and were used for case presentations, board review, and conferences. Selected images were transferred via a hospital network to workstations for consultation, saving time for referring clinicians. The teaching file is reliable, cost-effective, and easy to install and takes advantage of recent technologic advances in computer hardware and software. Rapid cost reductions and increases in PC storage capacity allow maintenance of the teaching file in DICOM format without intermediate steps involving automation or manual conversion. This setup rivals any of the proprietary software currently available from other vendors.

A computer-based training system for breast fine needle aspiration cytology.

Fine-needle aspiration (FNA) cytology is a rapid and inexpensive technique used extensively in the diagnosis of breast disease. To remove diagnostic subjectivity, a diagnostic decision support system (DDSS) called CytoInform has been developed, based on a Bayesian belief network (BBN) for the diagnosis of breast FNAs. In addition to acting as a DDSS, the system implements a computer-based training (CBT) system, providing a novel approach to breast cytology training. The system guides the trainee cytopathologist through the diagnostic process, allowing the user to grade each diagnostic feature using a set of on-screen reference images as visual clues. The trainee positions a slider on a spectrum relative to these images, reflecting the similarity between the reference image and the microscope image. From this, an evidence vector is generated, allowing the current diagnostic probability to be updated by the BBN. As the trainee assesses each clue, the evidence entered is compared with that of the expert through the use of a defined teaching file. This file records the relative severity of each clue and a tolerance band within which the trainee must position the slider. When all clues in the teaching case have been completed, the system informs the user of inaccuracies and offers the ability to reassess problematic features. In trials with two pathologists of different experience and a series of ten cases, the system provided an effective tool in conveying diagnostic evidence and protocols to trainees. This is evident from the fact that each pathologist only misinterpreted one case and a total of 86%/88% (experienced/inexperienced) of all clues assessed were interpreted correctly. Significantly, in all cases that produced the correct final diagnostic probability, the route taken to that solution was consistent with the expert's solution.

J. S. Ross: MRI of the spine, 2nd edn. (LWW MRI Teaching File Series)

J. S. Ross: MRI of the spine, 2nd edn. (LWW MRI Teaching File Series)

Electronic teaching files: seven-year experience using a commercial picture archiving and communication system.

With the advent of electronic imaging and the internet, the ability to create, search, access, and archive digital imaging teaching files has dramatically improved. Despite the fact that a picture archival and communication system (PACS) has the potential to greatly simplify the creation of, archival, and access to a department or multifacility teaching file, this potential has not yet been satisfactorily realized in our own and most other PACS installations. Several limitations of the teaching file tools within our PACS have become apparent over time. These have, at our facility, resulted in a substantially reduced role of the teaching file tools for conferences, daily teaching, and research purposes. With the PACS at our institution, academic folders can only be created by the systems engineer, which often serves as an impediment to the teaching process. Once these folders are created, multiple steps are required to identify the appropriate folders, and subsequently save images. Difficulties exist for those attempting to search for the teaching file images. Without pre-existing knowledge of the folder name and contents, it is difficult to query the system for specific images. This is due to the fact that there is currently no fully satisfactory mechanism for categorizing, indexing, and searching cases using the PACS. There is currently no easy mechanism to save teaching, research, or clinical files onto a CD or other removable media or to automatically strip demographic or other patient information from the images. PACS vendors should provide much more sophisticated tools to create and annotate teaching file images in an easy to use but standard format (possibly Radiological Society of North America's Medical Image Resource Center [MIRC] format) that could be exchanged with other sites and other vendors' PAC systems. The privilege to create teaching or conference files should be given to the individual radiologists, technologists, and other users, and an audit should be kept of who has created these files, as well as keep track of who has accessed the files. Vendors should maintain a local PACS library of image quality phantoms, normal variants, and interesting cases and should have the capability of accessing central image repositories such as the RSNA's MIRC images. Commercial PAC systems should utilize a standard lexicon to facilitate the creation and categorization of images, as well as to facilitate sharing of images and related text with other sites. This should be combined with a very easy to use mechanism to write images and related text when appropriate onto removable media (while maintaining a high level of security and confidentiality) to make it easier to share images for teaching, research, or clinical purposes.

The evolution of filmless radiology teaching

The transition from hard-copy film to the picture archiving and communication systems (PACS) arena is often a long and difficult path, but the complete transformation to the digital environment does not end with the successful clinical practice utilizing PACS. The next hurdle for academic institutions is similar changes in the teaching field. The loss of hardcopy films can greatly hinder the radiology teaching file and teaching conference experiences. The next step in our growth is the conversion to digital teaching files and conferences. The original work 10 years ago with utilizing computers linked with laser disks and magneto-optical media, have now evolved into complex networks with expanding and relatively cheap storage media, such as CD-ROM and easily to navigate graphic-user interfaces such as hypertext markup language (HTML) and extensible markup language (XML), for use with multimedia teaching tools. The transition into the digital arena for radiology education and interdepartmental conferences can be accomplished through several different paths. These include direct transfer of images into a presentation program, as well as exportation of images into suitable image file formats for later use. There is also the ability to expand the PACS network to include conference rooms. Similar training and teaching can allow radiologists to transition into the digital environment for future digital teaching file creation as well as correlative radiology interdepartmental conferences.