Case-based reasoning: opportunities and applications in health care.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to R T Macura.
Explore the source record for details and available documents.
The authors compiled a digital case library, a database of cases for intracranial masses, that can be used as an electronic teaching file and image source for case-based teaching applications, electronic textbooks, and diagnosis support tools. The library is a relational database with a feature-coded image archive that is structured around relevant radiologic findings. Its index for coding image content is structured as a hierarchical image description index that uses the relational format. Rules that control the search direction within the library and that generate lists of diagnostic hypotheses for decision support tools are embedded within the database structure. Currently, the library consists of 200 cases and 1,100 images that present intracranial masses on radiographs, computed tomograms, magnetic resonance images, and angiograms. Each image in the library is indexed according to its radiologic content. The user may search for reference images that contain particular radiologic features by formulating image content-based queries. The hierarchical index of radiologic findings allows multilevel query formulation that depends on the user's level of experience.
The authors have developed a comprehensive computer-based radiology information system known as "Radiology Resource and Review" (R3). The content is divided into 10 radiology information categories spanning the entire human body and presently includes more than 4 Mbytes of text, 9,000 topics, and 6,000 images. The R3 software and the information content are stored on compact disk, read-only memory (CD-ROM) media. The images are compressed by using a standard compression algorithm. Images and text are cross-indexed with more than 13,000 key words, which can be linked together in searches by using Boolean logic. Four different retrieval interfaces support browsing of text and image information, diagnosis decision making, self-study, and teaching file preparation. The 10-year university-funded evolution of R3 is an example of the transition in storage media from floppy disk to CD-ROM.
This paper focuses on the visual interface for image retrieval from radiology image database and describes a Radiologic Pictionary. A Radiologic Pictionary is a picture-based controlled vocabulary that allows visual query formulation by providing the user with images (samplers) that are linked to the hierarchical index of radiological findings and mapped into image data within the database. Samplers selected during query formulation point to image records that share their characteristics; all matching images are returned to the user.
RATIONALE AND OBJECTIVES: A computerized system that applies the case-based approach to training radiologists to diagnose brain tumors was designed. The authors attempted to provide residents a tool that supports their visual memory and inducts case-based reasoning. METHODS: A relational database with a digital image library was implemented and incorporated into a computer aided instruction environment based on case presentation. An indexing system was structured around case features (case history and radiologic findings). "If-then" type rules were used to control the search direction within the case library and to generate lists of diagnostic hypotheses. The indexing system was evaluated against cases "known" to the system. RESULTS: The current case library consists of 122 cases with 640 digitized images (computed tomography and magnetic resonance imaging). The accuracy of retrieval for "known" to the system cases was 80.7%. CONCLUSIONS: A case library stored on a personal computer can be efficiently searched for a combination of radiologic findings and can offer quality images for comparison to the case in question. A case library is a source of the information that may be used by different teaching applications.
We have implemented a tutoring system, Radiology Puzzler, for teaching visual recognition of intracranial lesions on radiological images. The system is designed to support the learning of radiological patterns through graphical case retrieval. Using radiologic feature samplers, the user may define brain lesion characteristics and use visual query when searching for reference cases. A rule-based module generates a hierarchical list of diagnostic hypotheses and provides a feed-back to the user. Relevant cases that match the sampler's index are retrieved from the case library for comparison with the case in question.
The paper describes the design of the Intelligent Radiology Workstation (IRW) that is intended to handle heterogeneous radiologic data (text, image, video) and radiologic knowledge in such a way that it is easy to store, access, use, and repurpose. An object-based structure is used to combine the relational database, hybrid knowledge base, and hypermedia within a common framework. Functions such as data entry and retrieval, browsing, and intelligent processing of data are available in the single environment. IRW open architecture allows radiologic digital resources to be used for clinical practice, diagnosis support, education, and research.