Image quality and diagnostic accuracy of coronary CT angiography derived from low-dose dynamic CT myocardial perfusion: a feasibility study with comparison to invasive coronary angiography.

OBJECTIVES: To investigate the diagnostic performance of coronary CT angiography derived from dynamic CT myocardial perfusion imaging (CCTACT-MPI) by third-generation dual-source CT with reference to invasive coronary angiography (ICA). MATERIALS AND METHODS: Patients with acute myocardial infarction and those who received successful reperfusion treatment were prospectively enrolled. Emergent ICA findings were used as the reference standard to assess the diagnostic performance of CCTACT-MPI for detection of significant coronary stenosis (diameter stenosis ≥ 50%). The radiation dose as well as image quality of CCTACT-MPI was also assessed. RESULTS: Twenty-six patients with 352 segments were ultimately included for analysis. The mean radiation dose of CCTACT-MPI generated from dynamic CT-MPI was 3.2 ± 1.1 mSv. Overall, 93.5% of total segments were interpretable (Likert score 2-4) whereas 6.5% segments were non-diagnostic (Likert score 1). Twenty-two patients with 84 segments were diagnosed by CCTACT-MPI as having ≥ 50% stenosis presence, whereas 268 segments had no obstructive stenosis. Compared to ICA findings, the overall diagnostic accuracy of CCTACT-MPI of patient-based and vessel-based as well segment-based analysis was 92.3%, 83.6%, and 85.8% respectively. As shown by ROC analysis, the AUC of CCTACT-MPI for detection of ≥ 50% stenosis was 0.833 on a per-patient level, 0.843 on a per-vessel level, and 0.822 on a per-segment level. CONCLUSIONS: CCTACT-MPI derived from dynamic CT-MPI was able to accurately diagnose obstructive coronary stenosis with reference to ICA. KEY POINTS: • CCTA derived from dynamic CT-MPI had a diagnostic image quality in 93.5% of total segments. • CCTA derived from dynamic CT-MPI was accurate in diagnosing obstructive CAD compared to ICA. • The mean radiation dose of dynamic CT-MPI for reconstruction of CCTA was 3.2 mSv.