COMPARATIVE-STUDY OF THALLIUM EMISSION MYOCARDIAL TOMOGRAPHY WITH 180-DEGREES AND 360-DEGREES DATA-COLLECTION

Abstract

Basic and clinical evaluation of Tl single-photon emission computed tomography (SPECT) using a rotating .gamma.-camera with 180.degree. (LPO-RAO) data collection was carried out and compared with the full 360.degree. rotation. No attenuation correction was used. In a phantom study the reconstructed image from the 180.degree. scan revealed better resolution. Although the 180.degree. scan, when compared with the 360.degree. scan, showed great photon attenuation in the deep location of a line source in water, this problem was not significant in the clinical study of 6 normal hearts. In 11 cases with myocardial infarction, the perfusion defect was more clearly visualized in the 180.degree. scan. The defect-to-normal (DIN) wall-count ratio was lower in the 180.degree. scan (0.48 .+-. 0.16; mean .+-. SD) than in the 360.degree. scan (0.61 .+-. 0.15, P < 0.05), indicating superior lesion contrast in the former. Apparently, for myocardial SPECT, the 180.degree. collection method is a more effective technique in the clinical evaluation of coronary artery disease.