Sun Yibo, Hua Yanqing, Wang Mingpeng, Mao Dingbiao, Jin Xiu, Li Cheng, Shi Kailei, Xu Jianrong
Department of Radiology, Renji Hospital Affiliated to Shanghai Jiaotong University School of Medicine, 160 Pu-jian Road, Shanghai 200127, China.
Department of Radiology, Huadong Hospital Affiliated to Fudan University, Shanghai, China.
Acad Radiol. 2017 Dec;24(12):1482-1490. doi: 10.1016/j.acra.2017.07.001. Epub 2017 Aug 8.
The study aimed to prospectively evaluate the radiation dose reduction potential and image quality (IQ) of a high-concentration contrast media (HCCM) injection protocol in combination with a low tube current (mAs) in coronary computed tomography angiography.
Eighty-one consecutive patients (mean age: 62 years; 34 females; body mass index: 18-31) were included and randomized-assigned into two groups. All computed tomography (CT) examinations were performed in two groups with the same tube voltage (100 kV), flow rate of contrast medium (5.0 mL/s), and iodine dose (22.8 g). An automatic mAs and low concentration contrast medium (300 mgI/mL) were used in group A, whereas effective mAs was reduced by a factor 0.6 along with HCCM (400 mgI/mL) in group B. Radiation dose was assessed (CT dose index [CTDI] and dose length product), and vessel-based objective IQ for various regions of interest (enhancement, noise, signal-to-noise ratio, and contrast-to-noise ratio), subjective IQ, noise, and motion artifacts were analyzed overall and vessel-based with a 5-point Likert scale.
The CT attenuation of coronary arteries and image noise in group B were significantly higher than those in group A (ranges: 507.5-548.1 Hounsfield units vs 407.5-444.5 Hounsfield units; and 20.3 ± 8.6 vs 17.7 ± 8.0) (P ≤ 0.0166). There was no significant difference between the two groups in signal-to-noise ratio, contrast-to-noise ratio, and subjective IQ of coronary arteries (29.4-31.7, 30.0-37.0, and medium score of 5 in group A vs 29.4-32.4, 27.7-36.3, and medium score of 5 in group B, respectively, P ≥ 0.1859). Both mean CTDI and dose length product in group B were 58% of those of group A.
HCCM combined with low tube current allows dose reduction in coronary computed tomography angiography and does not compromise IQ.
本研究旨在前瞻性评估在冠状动脉计算机断层扫描血管造影中，高浓度造影剂（HCCM）注射方案结合低管电流（毫安秒）时降低辐射剂量的潜力及图像质量（IQ）。
纳入81例连续患者（平均年龄：62岁；34例女性；体重指数：18 - 31），随机分为两组。两组所有计算机断层扫描（CT）检查均采用相同的管电压（100 kV）、造影剂流速（5.0 mL/s）和碘剂量（22.8 g）。A组使用自动毫安秒和低浓度造影剂（300 mgI/mL），而B组有效毫安秒降低0.6倍并使用HCCM（400 mgI/mL）。评估辐射剂量（CT剂量指数[CTDI]和剂量长度乘积），并使用5分制李克特量表对各感兴趣区域基于血管的客观IQ（强化、噪声、信噪比和对比噪声比）、主观IQ、噪声和运动伪影进行整体及基于血管的分析。
B组冠状动脉的CT衰减和图像噪声显著高于A组（范围：507.5 - 548.1亨氏单位对407.5 - 444.5亨氏单位；以及20.3±8.6对17.7±8.0）（P≤0.0166）。两组冠状动脉的信噪比、对比噪声比和主观IQ无显著差异（A组分别为29.4 - 31.7、30.0 - 37.0和5分制中等分数，B组分别为29.4 - 32.4、27.7 - 36.3和5分制中等分数，P≥0.1859）。B组的平均CTDI和剂量长度乘积均为A组的58%。
HCCM结合低管电流可在冠状动脉计算机断层扫描血管造影中降低剂量且不影响图像质量。
