Clinical experience with stress and delayed thallium-201 quantitative segmental washout curves (QSWC)

Stress thallium-201 myocardial studies in 29 patients with chest pain were performed. The findings of digital display (DD) and quantitative segmental washout curves (QSWC) were compared independently and jointly with coronary angiography. It was found that QSWC is more sensitive (71%) than DD (55%) but is less specific (58%) than DD (98%). Taking both approaches together the sensitivity rises to 94% and the specificity falls to to 61%. Using both DD and QSWC for interpretation of thallium studies improves the agreement ratio with coronary angiography by 25% more than when using DD only.