[Diagnosis of myocardial infarction using single photon emission computed tomography: comparison between visual and quantitative diagnosis].

For diagnosing myocardial infarction by myocardial scintigraphy using 201TlCl, the following two items were compared: 1) The diagnostic accuracy of visual evaluation of myocardial planar images versus that of single photon emission computed tomography (SPECT) images. 2) The diagnostic accuracy of qualitative and quantitative evaluations of SPECT images. The planar and SPECT methods were performed for 81 subjects consisting of 41 patients having myocardial infarction and 40 normal persons. Receiver operator characteristic (ROC) analysis, which is most objective in evaluation of visual diagnosis, was also used. To analyze quantitative diagnosis by ROC analysis, the normal range of circumferential profile analysis of myocardial short-axial tomography was determined by assessing five step divisions (less than 1 SD, 1-1.7 SD, 1.7-2.3 SD, 2.3-3 SD, and more than 3 SD) from 10 normal cases. Four physicians and three laboratory technicians familiar with myocardial images diagnosed the myocardial planar images and SPECT images individually. The results were analyzed and the ROC curves were constructed. The results indicated that image diagnosis by SPECT was superior to that by the visual planar method for all persons. The physicians who had more experience in diagnosing myocardial images made more accurate diagnosis. However, quantitative SPECT image diagnosis was superior to visual SPECT image diagnosis. Thus, with the input of data of the normal range of quantitative SPECT image diagnosis into the computer, the prospects of accurate computer assessments of myocardial infarctions were posed.(ABSTRACT TRUNCATED AT 250 WORDS)