Abstract
BACKGROUND: Coronary computed tomography angiography (CCTA) has provided excellent anatomical detail for coronary artery disease (CAD), but does not provide hemodynamic assessment. The application of conventional computed tomography perfusion (CTP) combined with CCTA to address this issue has been found to increase the scan time, radiation dose, and contrast media (CM). This study aimed to evaluate the feasibility of the low-dose "one-stop" myocardial CTP as an innovative computed tomography (CT) examination that could comprehensively assess patients suspected of CAD in a single scan. METHODS: Consecutive patients (n=94) with suspected CAD who underwent the 70 kV "one-stop" CTP and gender- and age-matched patients (n=62) who underwent conventional CCTA were included. The best enhanced CTP phase for coronary arteries was selected as the CCTA phase. The CM and effective dose (ED) were recorded. The image quality of the two groups was assessed. Patients who underwent CTP were divided into three groups [normal (0%, n=14), non-significant (1-49%, n=31), and significant stenosis (50-100%, n=49)] on the basis of degree of coronary stenosis. The cardiac function, myocardial strain, and myocardial blood flow (MBF) of each subgroup were analyzed. RESULTS: Compared to the conventional CCTA protocol, the ED of "one-stop" CTP reduced by 44.5% (4.13±0.33 vs. 7.56±1.43 mSv, P<0.05). Image noise in the CTP-derived CCTA phase was slightly higher (23.78±1.01 vs. 18.5±1.04, P<0.05). There were no significant differences in the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) between two groups (all P>0.05). The left ventricular ejection fraction (LVEF) and the absolute value of left ventricular (LV) global radial strain (GRS), circumferential strain (GCS), and longitudinal strain (GLS) decreased as the coronary stenosis increased (LVEF: r=-0.56; GLS: r=0.61; GCS: r=0.54; GRS: r=-0.46; P<0.05 for all comparisons). MBF was significantly higher in patients without CAD compared with those with non-significant and significant arterial stenosis (139.96±5.3 vs. 133.95±3.7 vs. 125.53±4.55 mL/100 mL/min, P<0.05 for all). MBF also varied significantly among territories supplied by coronary arteries with different stenosis, exhibiting a significant difference (all P<0.05). CONCLUSIONS: The advanced low-dose "one-stop" CTP protocol enables the simultaneous acquisition of coronary artery anatomy, ventricular function, myocardial strain, and hemodynamic information using low radiation dose and CM usage. This approach is beneficial for clinical decision-making and patient care in individuals with CAD.