双源CT前瞻性心电触发大螺距扫描腹部血管成像

目的 探讨双源CT前瞻性心电触发大螺距扫描应用于腹部CTA的可行性。方法 将40例临床疑诊腹部血管疾病、接受腹部CTA检查的患者随机分为2组,对A组采用前瞻性心电触发大螺距模式扫描,B组采用常规螺旋模式扫描,分别测量两组腹主动脉、腹腔干、脾动脉、肠系膜上动脉、右肾动脉、左肾动脉、腹主动脉分叉处、背部肌肉CT值及图像噪声,记录扫描时间及剂量长度乘积,并计算SNR、CNR和有效辐射剂量(ED)。比较两组各动脉的CT值、噪声、SNR、CNR、扫描时间、ED及图像质量差异。结果 两组腹主动脉、腹腔干、脾动脉、肠系膜上动脉、右肾动脉、左肾动脉、腹主动脉分叉处的CT值、SNR、CNR和图像质量差异均无统计学意义(P均>0.05),图像噪声、扫描时间及ED差异均有统计学意义(P均<0.05)。与B组相比,A组的扫描时间缩短86.45%、ED降低72.56%。结论 双源CT前瞻性心电触发大螺距扫描腹部CTA可在获得能够满足临床诊断要求图像的前提下大幅度降低患者的辐射剂量。

Prospectively electrocardiogram-triggered high-pitch spiral mode of dual-source CT in abdominal angiography

Objective To explore the feasibility of dual-source CT with prospectively ECG-triggered high-pitch spiral mode in abdominal angiography. Methods Forty patients of suspected abdominal aortic disease were randomly divided into 2 groups. Group A underwent prospectively ECG-triggered high-pitch spiral mode, and group B underwent routine spiral scan mode. The CT value and image noise of the abdominal aorta, celiac trunk, splenic artery, superior mesenteric artery, right renal artery, left renal artery, abdominal aortic bifurcation, muscles of back were measured. The scanning time and dose length product were recorded, and SNR, CNR and effective radiation dose (ED) were calculated. The CT value, image noise, SNR, CNR, scan time, ED and image quality between the two groups were analyzed. Results There were no significant differences in CT value, SNR, CNR and image quality of abdominal aorta, celiac trunk, splenic artery, superior mesenteric artery, right renal artery, left renal artery, abdominal aortic bifurcation (all P>0.05), while there were significant differences in image noise, scan time and ED between the two groups (all P<0.05). Compared with group B, the scan time of group A decreased 86.45%, and ED decreased 72.56%. Conclusion The prospectively ECG-triggered high-pitch spiral mode of dual-source CT in abdominal angiography can be used to significantly reduce radiation dose while image quality can meet the clinical diagnosis.