Causes of false-positive thallium-201 images in the diagnosis of coronary artery disease

ABSTRACT

In the diagnosis of coronary artery disease, thallium-201 scintigraphy can provide false-positive results. We studied 179 patients with no previous coronary artery bypass surgery who in 1980 had had thallium stress testing and coronary angiography within 3 months of the radionuclide study. Twenty-two patients were identified with 24 segmental defects in thallium distribution in regions supplied by normal coronary arteries. Two patients had primary myocardial disease, 2 had hypertrophic cardiomyopathy, 6 had left ventricular hypertrophy, and 12 had no cardiac abnormality. In a 1983 review of 18 of the 22 patients with false-positive results for coronary artery disease, 8 regions in 6 patients were still considered abnormal. The difference reflected the evolution of interpretation techniques. Identifiable causes of false-positive thallium scans included primary myocardial disease, left ventricular hypertrophy secondary to aortic stenosis, and perhaps hypertrophic obstructive cardiomyopathy. When these diseases are suspected, another method of diagnosing coronary artery disease should be used. Interpretation of the study using corroborative defects in multiple views will improve diagnostic accuracy.