Comparison of planar imaging and single-photon emission computed tomography for the detection and localization of coronary artery disease

Although single photon emission computed tomography (SPECT) has become widely utilized, the superiority of this technique compared to planar conventional imaging remains controversial. In order to compare these two techniques, we retrospectively analysed the results obtained in 70 patients who performed a thallium-201 exercise scintigraphy with a double acquisition during the same test, and who also underwent coronary and ventricular angiography. Overall, SPECT imaging yielded a higher sensitivity (93% vs 82% for SPECT and planar imaging respectively, p < 0.05), especially in the inferior and anterior regions. SPECT was also more sensitive for the detection of a single-vessel disease (90% vs 74% for SPECT and planar imaging respectively, p < 0.01). The specificity was assessed for both techniques with the help of circumferential computerized analysis, avoiding known causes of false positive scintigrams. We found a high specificity for both SPECT and planar imaging, without any significant difference between the two methods (87% vs 91% for the overall specificity of SPECT and planar imaging respectively, p = NS). Therefore, SPECT imaging analysed with discrimination shows an enhanced reliability over planar imaging for the detection and the localization of coronary artery disease, without increasing the risk of false positive tests.