[Efficacy of simultaneous function and perfusion imaging on 99mTc-tetrofosmin myocardial scintigraphy]

The aim of this study was to determine whether the diagnosis for coronary artery disease (CAD) with 99mTc-tetrofosmin (Tf) myocardial scintigraphy was improved by the combination of function image and perfusion image as compared with perfusion alone. Tf myocardial scintigraphy was performed with one-day protocol (stress/rest) in 51 patients (CAD: 32, Non-CAD: 19) without previous myocardial infarction. Function image was obtained by first pass method, and perfusion image by SPECT. Number of diseased vessels was 14 in right coronary artery (RCA), 18 in left anterior descending (LAD), and 12 in left circumflex (LCX). Ischemia was diagnosed by 2 different parameters 1) perfusion image alone, 2) combination of perfusion image and regional ejection fraction (rEF). On perfusion image, accuracy was 53%, 94% and 86% in RCA, LAD, and LCX respectively. On perfusion + rEF, accuracy was 76%, 90% and 84% in RCA, LAD, and LCX respectively. Specificity in RCA was 45% on perfusion, 84% on perfusion + rEF. Sensitivity in RCA was 77% on perfusion, 54% on perfusion + rEF. LAD and LCX did not change by the addition of function image. By addition of function image, accuracy and specificity of diagnosis in area of RCA improved significantly (p < 0.01). Thus the addition of function image in Tf myocardial scintigraphy would be useful to improve the diagnosis, especially in region of RCA.