Department of Radiology, The Affiliated Hospital of Hebei University, Baoding City, China.
J Xray Sci Technol. 2022;30(6):1261-1272. doi: 10.3233/XST-221263.
To compare image quality, radiation dose, and iodine intake of coronary computed tomography angiography (CCTA) acquired by wide-detector using different tube voltages and different concentrations of contrast medium (CM) for overweight patients.
A total of 150 overweight patients (body mass index≥25 kg/m2) who underwent CCTA are enrolled and divided into three groups according to scan protocols namely, group A (120 kVp, 370 mgI/ml CM); group B (100 kVp, 350 mgI/ml CM); and group C (80 kVp, 320 mgI/ml CM). The CT values, signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and figure-of-merit (FOM) of all images are calculated. Images are subjectively assessed using a 5-point scale. In addition, the CT dose index volume (CTDIvol) and dose length product (DLP) of each patient are recorded. The effective radiation dose (ED) is also calculated. Above data are then statistically analyzed.
The mean CT values, SNR, CNR, and subjective image quality of group A are significantly lower than those of groups B and C (P < 0.001), but there is no significant difference between groups B and C (P > 0.05). FOMs show a significantly increase trend from group A to C (P < 0.001). The ED values and total iodine intake in groups B and C are 30.34% and 68.53% and 10.22% and 16.85% lower than those in group A, respectively (P < 0.001).
The lower tube voltage and lower concentration of CM based on wide-detector allows for significant reduction in iodine load and radiation dose in CCTA for overweight patients comparing to routine scan protocols. It also enhances signal intensity of CCTA and maintains image quality.
比较使用不同管电压和不同浓度对比剂（CM）的宽探测器冠状动脉计算机断层扫描血管造影（CCTA）在超重患者中的图像质量、辐射剂量和碘摄入量。
共纳入 150 名超重患者（体重指数≥25kg/m2），根据扫描方案分为三组，A 组（120kVp，370mgI/ml CM）；B 组（100kVp，350mgI/ml CM）；C 组（80kVp，320mgI/ml CM）。计算所有图像的 CT 值、信噪比（SNR）、对比噪声比（CNR）和品质因数（FOM）。使用 5 分制对图像进行主观评估。此外，还记录每位患者的 CT 剂量指数体积（CTDIvol）和剂量长度乘积（DLP）。还计算了有效辐射剂量（ED）。然后对以上数据进行统计学分析。
A 组的平均 CT 值、SNR、CNR 和主观图像质量明显低于 B 组和 C 组（P<0.001），但 B 组和 C 组之间无显著差异（P>0.05）。FOM 呈从 A 组到 C 组的显著上升趋势（P<0.001）。B 组和 C 组的 ED 值和总碘摄入量分别比 A 组低 30.34%和 68.53%、10.22%和 16.85%（P<0.001）。
与常规扫描方案相比，基于宽探测器的较低管电压和较低 CM 浓度可显著降低超重患者 CCTA 的碘负荷和辐射剂量，同时增强 CCTA 的信号强度并保持图像质量。
