Serial thallium-201 imaging after dipyridamole for coronary disease detection: quantitative analysis using myocardial clearance.
After dipyridamole, canine studies have demonstrated a slower rate of myocardial thallium-201 clearance from zones distal to a coronary artery stenosis compared to normal zones. To determine if criteria based on canine myocardial thallium-201 clearance rates could be applied clinically, 40 patients with and 26 patients without coronary artery disease (CAD) had serial thallium-201 images obtained for 2 to 5 hours after dipyridamole. Regions of interest were manually placed over six left ventricular segments in two projections for each of three imaging times. The myocardial thallium-201 clearance rate was calculated for each of the six segments and, using the clearance rate criterion found in canine studies, was considered abnormal if less than 6.5%/hr. Using this criterion alone, 22 of 26 patients (85%) without CAD had normal and 30 of 40 patients (75%) with CAD had abnormal myocardial thallium-201 clearance rates. A quantitative analysis of regional inhomogeneity in tracer distribution (normal was greater than or equal to 25% difference between segments) was negative in 24 of 26 patients (92%) without CAD and positive in 20 of 40 patients (50%) with CAD. When both clearance rate and regional inhomogeneity were considered, 21 of 26 patients (81%) without CAD had negative and 36 of 40 patients (90%) with CAD had positive results. Thus, post-dipyridamole myocardial clearance rate criteria derived from canine studies can be applied to clinical thallium imaging. Quantitative analysis of serial thallium-201 images after dipyridamole is optimized by using myocardial thallium-201 clearance rates. Such an approach is independent of regional inhomogeneities in tracer distribution.
D000328:Adult; D000368:Aged; D003327:Coronary Disease / Q000175:diagnosis / Q000000981:diagnostic imaging*; D004176:Dipyridamole; D005260:Female; D006321:Heart / Q000000981:diagnostic imaging*; D006801:Humans; D008297:Male; D008722:Methods; D008875:Middle Aged; D009206:Myocardium / Q000378:metabolism; D011433:Propranolol / Q000494:pharmacology; D011868:Radioisotopes / Q000378:metabolism; D011877:Radionuclide Imaging; D012737:Sex Factors; D013793:Thallium / Q000378:metabolism
D011868:Radioisotopes; D004176:Dipyridamole; D011433:Propranolol; D013793:Thallium