Tc-99m-MIBI 심근 SPECT 극성지도 분석에 의한 심근 기능의 정량적 평가 = A Quantitative Method for the Assessment of Myocardial Function using the Polar Analysis of Tc-99m-MIBI Myocardial SPECT

다국어 초록 (Multilingual Abstract)

As the Tc-99m-MIBI myocardial SPECT demonstrated wide application in the diagnosis of myocardial function the quantitative and severity-dependent information is currently required. In this study, we proposed a computerized method for scoring the fixed devects in terms of extent-weighted severity and for identifying the reversibility in ischemic regions. At the first stage of this method, the transverse slices were reconstructed with (1.4 Nyquist freq. and order 5 Butterworth filter. From the oblique/sagittal slices, maximal count per pixel circumperential profiles were extracted for each sector, and then stress/ redist. polar maps were normalized and plotted. For reversibility, the stress polar map was subtracted from the delayed miage and positive-valued pixels were categorized into three grades. The extent-weighted seerity scores were calculated using the assigned grades and their number of pixels. This procedure was done automatically and the reversibility and severity scores were produced for each of the coronary territories (LAD, RCA, LCX) of any combination of these. Clinical application has shown that the changes in reversibility scores after PTCA were correated linearly with the pre PTCA scores(r>0.8) in postinfarct cases as well as in angina, and seerity scores of persistent devects in stress/rest SPECT study matched to the regional ejection fraction and visual analysis of regioal wall motion of gated blood pool scan(r>0.6). We conclude that the computerized severity scoring method for the analysis of myocardial SPECT could be useful in the assessment of the myocardial ischemia and fixed defect.