Problem-oriented Prefetching for an Integrated Clinical Imaging Workstation
- Correspondence and reprints: Alex Bui, PhD, Telemedicine Division, UCLA Department of Radiology, 924 Westwood Boulevard, Suite 420, Los Angeles, CA, 90024; e-mail: <buia{at}cs.ucla.edu>
- Received 15 October 1998
- Accepted 18 January 2001
Abstract
Prefetching methods have traditionally been used to restore archived images from picture archiving and communication systems to diagnostic imaging workstations prior to anticipated need, facilitating timely comparison of historical studies and patient management. The authors describe a problem-oriented prefetching scheme, detailing 1) a mechanism supporting selection of patients for prefetching via characterizations of clinical problems, using multiple data sources (picture archiving and communication systems, hospital information systems, and radiology information systems), classifying patients into cohorts on the basis of their medical conditions (e.g., lung cancer); and 2) prefetching of multimedia data (imaging, laboratory, and medical reports) from clinical databases to enable the viewing of an integrated patient record. Preliminary evaluation of the prefetching algorithm using classic information retrieval measures showed that the system had high recall (100 percent), correctly identifying and retrieving data for all patients belonging to a target cohort, but low precision (50 percent). A key finding during testing was that the recall of the system was increased through the use of multiple data sources (compared with one data source), because of better patient descriptors. Medical problems and patient cohorts were more specifically defined by combining information from heterogeneous databases.
Footnotes
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This work was funded by grant PO1-CA51168-07 from the National Institutes of Health (NIH).
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↵* That is not to say that codes are not used in reporting. For example, ICD-9 codes sometimes appear in free-text reports to facilitate billing, but such codes are not stored in separate, searchable fields. Moreover, current manual coding of procedures for billing (e.g., CPT) can take several hours or days to complete, beccause of personnel limitations, so it is not helpful in prospective identification of patients.
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↵† These searches are deemed heuristic, since they assume that patient information that was seen once on the workstation is likely to be seen again and should be prefetched; this assumption is not always true but appears to be a sound guideline.
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↵† Several of these patients were, in actuality, prefetched multiple times because of sequential imaging to track progress; for each event, OITL correctly performed prefetching of the patient's data.
