团注追踪法下不同监测点对冠状动脉CT血管成像图像质量的影响

目的 评估对比剂团注追踪法下不同监测点对冠状动脉CT血管成像（CCTA）图像质量的影响。方法 前瞻性将128例拟行CCTA检查患者随机分为不同监测点组：左心房（LA）组、左心室（LV）组、升主动脉（AA）组、降主动脉（DA）组，每组32例。阈值为130 HU，对比剂使用碘美普尔（含碘400 g/L），注射速率为4 mL/s，用量为40 m L。比较4组间的主、客观图像评价指标及辐射剂量参数的差异。结果 4组患者的主动脉根部、左主干CT值差异有统计学意义（均P<0.05），其中LA组主动脉根部及左主干CT值均高于其他3组；4组前降支近段、回旋支近段及右冠状动脉中段CT值差异无统计学意义（均P>0.05）。4组图像噪声、左主干及右冠状动脉对比噪声比间差异有统计学意义（均P<0.05）,LA组图像噪声较低。4组主动脉根部信噪比及对比噪声比、左主干及右冠状动脉信噪比间差异无统计学意义（均P>0.05）。4组间主观图像质量评分及辐射剂量相关参数比较差异均无统计学意义（均P>0.05）。结论在使用对比剂团注追踪法的CCTA扫描中，将监测点定位于左心房内可以获得更好的图...

Effects of different monitoring points on coronary CT angiography image quality under the bolus-tracking method

Objective To evaluate the effect of different monitoring points on the image quality of coronary CT angiography (CCTA) under the bolus-tracking method. Methods A total of 128 prospective patients undergoing CCTA examination were randomly divided into 4 different monitoring points groups: the left atrium (LA) group, the left ventricle (LV) group, the ascending aorta (AA) group and the descending aorta (DA) group. Each group contained 32 patients. The ROI threshold was 130 HU, the contrast agent was iomeprol (contain iodine 400 g/L), and the injection rate was 4 mL/s and the dosage was 40 mL. The differences in subjective and objective image evaluation indicators and radiation dose parameters were compared between the 4 groups. Results There were significant differences in CT values of aortic root and left main of coronary artery between the 4 groups (P<0.05). The CT values of aortic root and left main were higher in the LA group than those of the other three groups. There were no significant differences in CT values of proximal left anterior descending artery, proximal left circumflex artery and the mid of right coronary artery in the 4 groups (P>0.05). The differences in image noise and right coronary contrast-to-noise ratio (CNR) were statistically significant between the 4 groups (all P<0.05). The image noise in the LA group was 21.00±4.11, which was lower than other three groups. There were no significant differences in aortic signal-to-noise ratio (SNR) and CNR, left main and right coronary artery SNR between the 4 groups (P>0.05). There were no significant differences in subjective image quality score and radiation dose-related parameters between the 4 groups (P>0.05). Conclusion In CCTA scan using contrast agent bolus tracking method, positioning the monitoring point in left atrium can obtain better image quality, which is an ideal monitoring point for CCTA examination.