522Original Article Improved Diagnostic Performance of Thallium-201 Myocardial Perfusion Scintigraphy in Coronary Artery Disease: from Planar to Single Photon Emission Computed Tomography Imaging

Background: This study was performed to compare Tl-201 myocardial perfusion single photon emission computed tomography (SPECT) with planar scintigraphy in the diagnosis of coronary artery disease (CAD). Methods: Retrospectively, 240 of 3262 patients, with exercise-redistribution Tl-201 myocardial perfusion scintigraphy performed between January 1990 and October 1997, were analyzed to compare Tl-201 scintigraphy and coronary arteriography. Within 30 days, all 240 patients underwent both coronary arteriography and exercise-redistribution Tl-201 myocardial perfusion scintigraphy with 86 SPECT and 154 planar images acquired. Results: The sensitivities of Tl-201 myocardial perfusion scintigraphy in individual coronary arteries including left anterior descending (LAD) artery, left cir-cumflex (LCX) artery, and right coronary artery (RCA), were 77%/72%, 31%/30%, and 77%/50 % in the SPECT/planar study groups, respectively. The sensitivities of CAD detection in patients with single-vessel, double-ves-sel, and triple-vessel diseases were 96%/82%, 91%/85%, and 96%/90 % in the SPECT/planar study groups, respectively. Conclusion: SPECT images provide greater advantages over planar images for better detection of the number, location, and extent of CAD. Cardiac SPECT does improve the accurate interpretation in abnormal Tl-201 distributions due to the higher contrast resolution and better separation of overlapping myocar-dial regions