[Automatic quantitative analysis of myocardial tomography thallium-201 scintigraphy]

An automatic and quantitative analysis method for tomographic scintigraphy was applied to 104 patients with myocardial infarction (anterior 37, inferior 67, lateral 20, involving 2 territories in some cases). All patients underwent exercise and redistribution scintigraphy and coronary arteriography which served as reference. Two types of tomographic sections were used: 2 short axis sections exploring the left ventricle at different levels, and 1 apical section at a right angle with the first ones. A circumferential analysis program studied the isotopic activity of each section and drew an activity profile curve which was compared with those obtained in normal subjects. Exercise curves proved superior to redistribution and wash-out curves and were therefore used exclusively. Two sectoring methods for territories with infarcts were defined: conventional sectoring, which gives a 90 degrees angle to the anterior region and a 180 degrees angle to the inferior lateral region, and real sectoring established from the scintigraphic abnormalities observed in patients whose infarction was not accompanied by significant lesions in other territories. Real sectoring divides the territory into two regions (anterior and infero-lateral) and determines the extension territory and the territories specific to each necrotic region. The sensitivity and specificity of these two methods for the diagnosis of necrosis and the detection of a significant abnormality (greater than 70% stenosis, or necrosis) in a territory other than the one with infarct were compared. In the diagnosis of infarction: conventional sectoring sensitivity 92%, specificity 46% for anterior infarcts, 94% and 25% for inferior and lateral infarcts; real sectoring 94% and 63% respectively for anterior infarcts, 92% and 68% for inferior infarcts.(ABSTRACT TRUNCATED AT 250 WORDS)