Myocardial CT perfusion imaging and atherosclerotic plaque characteristics on coronary CT angiography for the identification of myocardial ischaemia

Abstract

To investigate the value of myocardial computed tomography (CT) perfusion imaging (CTP) and atherosclerotic plaque characteristics (APCs) identified on coronary CT angiography (CCTA) for the detection of myocardial ischaemia by using single-photon-emission CT (SPECT) as a reference. Thirty-six patients (63.9% males) undergoing combined stress dynamic CTP and CCTA were enrolled and analysed. Myocardial blood flow (MBF) from CTP was quantified and compared between normal and abnormal segments. The ability of CTP and APCs to detect ischaemia was compared to that of SPECT. Nineteen patients with 78 segments had perfusion abnormalities on CTP. A significant difference was seen in MBF values between normal (118.51±27.86 ml/100 ml/min) and hypoperfused (79.60±21.35 ml/100 ml/min) segments (t=15.832, p<0.05). The sensitivity and specificity for identifying ischaemia were 90.91% and 94.97%, respectively, on a per-segment basis, resulting in a r value of 0.737 (p<0.05). On a per-vessel basis, the sensitivity and specificity for detecting ischaemia were 86.67% and 84.62%, respectively, for CTP; 93.33% and 58.97%, respectively, for CCTA; and 86.67% and 87.18%, respectively, for CTP combined with CTA, with an area under the receiver-operator characteristic curve (AUC) being 0.87 (p<0.05) and 0.887 (p<0.05) for CTP and its combination with CTA, respectively. On CCTA, 55 vessels with APCs were detected, with an AUC of 0.737 (p<0.05) for APCs combined with CCTA stenosis and 0.802 (p<0.05) for APCs combined with CTP. Dynamic stress CTP shows good correlation with SPECT for the detection of ischaemia. Additionally, combining APCs with CCTA stenosis has the ability to discriminate ischaemic stenosis.