Feasibility of dynamic myocardial CT perfusion using single-source 64-row CT

BackgroundDynamic myocardial computed tomography perfusion (CTP) is an emerging technique to diagnose significant coronary stenosis. However, this procedure has not been reported using single-source 64-row CT.ObjectiveTo investigate the radiation dose and the diagnostic performance of dynamic CTP to diagnose significant stenosis by catheter exam.MethodsWe prospectively included 165 patients who underwent CTP exam under adenosine stress using a single-source 64-row CT. MBF was calculated using the deconvolution technique. Quantitative perfusion ratio (QPR) was defined as the myocardial blood flow (MBF) of the myocardium with coronary stenosis divided by the MBF of the myocardium without significant stenosis or infarct. Of the 44 patients who underwent subsequent coronary angiography, we assessed the diagnostic performance to diagnose ≥50% stenosis by quantitative coronary analysis (QCA).ResultsThe average effective dose of dynamic CTP and the entire scans were 2.5 ± 0.7 and 7.3 ± 1.8 mSv, respectively. The MBF of the myocardium without significant stenosis was 1.20 ± 0.32 ml/min/g, which significantly decreased to 0.98 ± 0.24 ml/min/g (p < 0.01) in the area with ≥50% stenosis by CT angiography. The QPR of the myocardium with QCA ≥50% stenosis was significantly lower than 1 (0.84 ± 0.32, 95% confidence interval (CI), 0.77–0.90, p < 0.001). The accuracy to detect QCA ≥50% stenosis was 82% (95%CI, 74–88%) using CT angiography alone and significantly increased to 87% (95%CI, 80–92%, p < 0.05) including QPR.ConclusionDynamic myocardial CTP could be performed using 64-row CT with a low radiation dose and would improve the diagnostic performance to detect QCA ≥50% stenosis than CT angiography alone.