Stress dynamic CT myocardial perfusion imaging combined with coronary CT angiography for the detection of ischemic coronary artery disease

Objective To assess effects of stress dynamic CT myocardial perfusion imaging (CT-MPI) combined with coronary CT angiography (CCTA) on the diagnosis of myocardial perfusion defects in coronary artery disease (CAD). Methods Patients with CAD diagnosed by CCTA underwent ATP stress CT-MPI examination. Single-photon emission computed tomography (SPECT) myocardial perfusion imaging (SPECT-MPI) was performed within one week and set as the reference standard. CT-MPI results were qualitatively analyzed, and myocardial blood flow (MBF), myocardial blood volume (MBV) as well as time to peak (TTP) were quantified according to CT-MPI. Effects of CCTA, CT-MPI, and CT-MPI combined with CCTA on predicting myocardial perfusion defects were assessed in comparison with NMPI. Results Thirty patients [(54.8±8.4)years] were enrolled in our study, 20 were men (68%). MBF [(79.3±18.0) versus (135.1±35.2) ml·100 ml-1·min-1] and MBV [(8.9±2.9) versus (13.8±8.9) ml/100 ml] were significantly decreased in hypoperfused segments compared with normal segments, while TTP was increased in hypoperfused segments [(13.9±2.5)s] compared with normal segments [(9.1±2.1)s] (t=0.302, 0.866 and 0.024 respectively, all P values<0.01). The sensitivity, specificity of CT-MPI for identifying segments with perfusion defects were 91.3%(147/161), 84.6%(281/332), respectively. On a per-vessel basis, the area under the receiver operating characteristic curve for predicting myocardial perfusion defects were 0.635 (95% CI: 0.517—0.753) for CCTA, 0.709 (95%CI: 0.599—0.819) for CT-MPI, and 0.837 (95%CI: 0.749—0.925) for CT-MPI combined with CCTA, respectively. Conclusions The performance of stress dynamic CT-MPI in the diagnosis of myocardial perfusion defects in CAD was good. One-stop examination of CT-MPI combined with CCTA improves the diagnostic accuracy for identifying flow-obstructing stenosis. Key words: Myocardial ischemia; Tomography, X-ray computed; Myocardial perfusion imaging; Coronary stenosis