Discordance of visual and quantitative analysis regarding false negative and false positive test results in thallium-201 myocardial perfusion scintigraphy.

Visual assessment and quantitative analysis of exercise thallium-201 myocardial perfusion scintigraphy was performed in 203 consecutive patients who underwent coronary arteriographic studies to identify the factors associated with false negative and false positive studies. Also the discordance between visual and quantitative analysis was evaluated. One hundred sixty-two (80%) of these 203 patients had significant coronary artery disease (CAD), i.e. a luminal stenosis greater than or equal to 50%. Fifty-two (32%) of these 162 patients with documented CAD showed negative thallium results either by visual or quantitative analysis. When interpreted visually 36/162 (22%) of patients were judged as negative, and when analyzed quantitatively 41/162 (25%) of patients were judged as negative (ns). Of the total group of 52 patients with false negative visual and/or quantitative analysis test results, 27 (17%) showed discordance between these two methods. Of the 41 patients without significant CAD, 12 (29%) showed positive thallium findings. Visual interpretation was positive in 9/41 (22%) of patients without significant CAD, and quantitative analysis in 5/41 (12%) (ns). Of the total group of 12 patients with positive visual and/or quantitative analysis test results, 10 (24%) showed discordance between these two methods. Therefore, in the total group, 37 patients (18%) showed discordance between visual and quantitative analysis. It is concluded that 1) the sensitivity and the specificity of visual interpretation and quantitative analysis of thallium-201 exercise scintigraphy for detecting CAD is similar, and 2) that there is frequent discordance of visual interpretation and quantitative analysis in thallium-201 exercise scintigraphy.