Simultaneous Transmission/Emission Myocardial Perfusion Tomography

Abstract

Background The purpose of the present study was to assess the diagnostic performance of attenuation-corrected (AC) stress 99m Tc-sestamibi cardiac single-photon emission computed tomography (SPECT) for the identification of coronary heart disease (CHD). Methods and Results With a triple-detector SPECT system with a 241 Am transmission line source, simultaneous transmission/emission tomography (TCT/ECT) was performed on 60 patients with angiographic coronary disease and 59 patients with ≤5% likelihood of CHD. Iteratively reconstructed AC stress 99m Tc-sestamibi perfusion images were compared with uncorrected (NC) filtered-backprojection images. Normal database polar maps were constructed from AC and NC images for quantitative analyses. From the low-likelihood patients, the visual and quantitative normalcy rates increased from 0.88 and 0.76 for NC to 0.98 and 0.95 for AC ( P <.05). For the detection of CHD, the receiver operating characteristic curves for the AC images demonstrated improved discrimination capacity ( P <.05), and sensitivity/specificity values increased from 0.78/0.46 (NC) to 0.84/0.82 (AC) with visual analysis and from 0.84/0.46 (NC) to 0.88/0.82 (AC) with quantitative analysis. For localization of stenosed vessels, visual and quantitative sensitivity values were 0.51 and 0.63 for NC and 0.64 and 0.78 for AC images ( P <.05), respectively. Conclusions TCT/ECT myocardial perfusion imaging significantly improves the diagnostic accuracy of cardiac SPECT for the detection and localization of CHD. Clinical use of TCT/ECT imaging deserves serious consideration.