On the clinical value of thallium-201 washout analysis in the detection of multiple jeopardized myocardial regions.

In this study the relative importance of visual assessment and quantitative analysis myocardial stress perfusion scintigraphy in 72 patients with a 40% incidence of triple-vessel coronary disease was tested. The quantitative analysis of the uptake scintigram in combination with a washout rate study of thallium-201 was not superior to the visual analysis with regard to the overall detection of significant coronary disease (obstructions of at least 50%). The sensitivity of the quantitative analysis was 0.85 for the entire population and 0.90 for the triple-vessel disease group (specificity 0.90). Detection of jeopardized myocardial flow regions in patients with triple-vessel disease, however, resulted in a significantly better identification by quantitative analysis. Of the 87 jeopardized flow regions in the 29 patients with triple-vessel disease, 62 regions were detected by the quantitative analysis whereas 48 regions were noted by the visual evaluation. The post-test likelihood of this regional quantitative analysis with respect to the triple-vessel disease was 66%. The incidence of global ischemia as detected by washout abnormalities in cases with no or a maximum of one regional uptake defect was 7%.