[Transaxial tomography in the study of myocardial perfusion with thallium-201]

Stress and redistribution thallium-201 myocardial imaging using a transaxial single emission computed tomographic system has been applied to the diagnosis of coronary artery disease. Data sampling was performed along a limited 180 degree arc, obtaining 32 images in a continuous mode, at a rate of 20 seconds per image. The production of perfusion defects in patients was stimulated by exercise testing or by dipyridamole infusion. No significant differences existed when both tests were compared (p less than 0.01). Normal and abnormal patterns including the different pathophysiological alterations of myocardial ischemia were defined in three tomographic planes using this methodology. Patients with coronary disease are separated from patients without coronary disease with high probability (84%). Transaxial SPECT (single photon emission computerized tomography) provides a significant increment in sensitivity and specificity in relation to planar scintigraphy in the detection of myocardial infarction (91 and 100%, respectively); residual ischemia postinfarction (96 and 97%, respectively), and significant coronary artery disease (91 and 97%, respectively).