论文部分内容阅读
目的:探讨在动态心肌CT灌注成像（CTP）检查中，根据患者体质指数（BMI）以及体质量（kg）制定个体化扫描和对比剂注射方案，以期得到优质图像的同时大幅降低辐射剂量的可行性。方法:2019年6月至2020年3月前瞻性连续入选中国医学科学院阜外医院128例患者，所有患者经冠状动脉CTA（CCTA）诊断为冠心病而行负荷CTP检查，根据BMI和体质量分为6组：组1，BMI28 kg/mn 2，体质量>80 kg；不同BMI组分别应用70、80、100 kV管电压，200 mA固定管电流扫描，6组注射对比剂的碘流率分别为0.8、1.0、1.2、1.4、1.6和2.0 g/s，均使用含碘370 mg/ml对比剂。测量每组左心室腔及心肌室间隔的CT值和噪声，得到图像的信噪比（SNR）和对比度噪声比（CNR），所有参数均采用Shapiro-Wilk检验分析数据正态性，符合正态分布的参数间比较采用单因素方差分析。n 结果:组1~6患者的左心室腔CT值分别为（506±85）、（513±77）、（510±81）、（456±74）、（477±111）、（462±43）HU，差异无统计学意义（n F=2.249，n P=0.054）；左心室腔的SNR分别为23±8、20±5、21±5、19±4、19±7和19±4，CNR分别为19±7、17±4、17±4、16±4、15±6和15±4，差异均无统计学意义（n F值分别为1.674、1.736，n P值均>0.05）。单次CTP扫描下使用70、80和100 kV组的辐射剂量分别为1.6、2.3、4.3 mSv，70和80 kV组均显著低于100 kV组，70 kV 组亦显著低于80 kV组（n P值均28 kg/mn 2,>80 kg, 100 kV. 200 mA was fixed for all patients. Contrast agent with iodine containing 370 mg/ml was used in all patients. The iodine delivery rates (IDR) for each group was 0.8, 1.0, 1.2, 1.4, 1.6, 2.0 g/s, respectively. The attenuation and noise of left ventricle (LV) and septal myocardial were measured to calculate signal to noise ratio (SNR) and contrast to noise ratio (CNR) of the images in each group. The Shapiro-Wilk test was conducted to assess the normality of quantitative data. Quantitative variables were compared using one-way ANOVA if normally distributed.n Results:The LV attenuation of the six groups were (506±85), (513±77), (510±81), (456±74), (477±111), (462±43) HU, respectively. There was no significant difference among them (n F=2.249,n P=0.054). SNR values of LV were 23±8, 20±5, 21±5, 19±4, 19±7, 19±4, and CNR values were 19±7, 17±4, 17±4, 16±4, 15±6, 15±4, respectively. There were no significant differences among them (n F=1.674, 1.736, all n P>0.05). Under a single CTP scan, the radiation dose of 70, 80 and 100 kV groups were 1.6, 2.3 and 4.3 mSv, respectively. The does of the 70 kV group and 80 kV group were significantly lower than that of the 100 kV group, and the dose of the 70 kV group was also significantly lower than that of the 80 kV group (alln P<0.001).n Conclusions:The application of individualized scanning and contrast agent injection protocol based on IDR is feasible in myocardial CTP with successful image quality, and the radiation dose decreases significantly.