Liang Jixiang, Kong Lingyan, Jin Zhengyu, Wang Yun, Xue Huadan, Wang Yining, Zhang Daming, Chen Jin
Department of Radiology,PUMC Hospital,CAMS and PUMC,Beijing 100730,China.
Zhongguo Yi Xue Ke Xue Yuan Xue Bao. 2017 Feb 20;39(1):68-73. doi: 10.3881/j.issn.1000-503X.2017.01.012.
Objective To evaluate the value of third-generation dual-source CT scanner in application of high-pitch aorta CT angiography(CTA). Methods Totally 59 patients clinically indicated for whole aorta angiography were divided into 2 groups using a simple random method:in group 1 there were 28 patients who underwent the examination on a third-generation dual-source CT device,with a collimation of 2×192×0.6 mm and a rotation time of 0.25 s;in group 2 there were 31 patients who underwent the examination on a second generation dual-source CT device,with a collimation of 2×128×0.6 mm and a rotation time of 0.28 s. Both groups were given the examination operated in dual-source high-pitch ECG-gating mode with a pitch of 3.0,a tube voltage of 100 kV,and automated tube current modulation using a reference tube current of 288 mA. A contrast material bolus of 45 ml with a flow of 4.5 ml/s followed by a 50 ml saline chaser in 5.0 ml/s was used. CTA scan was automatically started using a bolus tracking technique at the level of the original part of aorta after a trigger threshold of 100 HU was reached. The start delay was set to 6 s in both groups. Effective dose(ED),signal to noise ratio (SNR),contrast to noise ratio (CNR),and subjective diagnostic quality of both groups were evaluated. Results The mean ED were 19.44% lower (t=-3.989,P=0.000) in group 1 [(3.15±0.86)mSv] than in group 2 [(3.91±0.60)mSv]. These two groups showed no significant differences in SNR or CNR (all P >0.05). The subjective diagnostic quality values also showed no significant difference between two groups [(1.39±0.50)scores vs. (1.45±0.51)scores;W=814.5,P=0.651].Conclusion Compared with the second-generation dual-source CT scanner,the third-generation dual-source CT scanner in whole aorta CTA can remarkably reduce the radiation dose without affecting image quality.
目的 评估第三代双源CT扫描仪在高心率主动脉CT血管造影（CTA）中的应用价值。方法 将59例临床拟行全主动脉血管造影的患者采用简单随机法分为2组：第1组28例，采用第三代双源CT设备进行检查，准直为2×192×0.6 mm，旋转时间为0.25 s；第2组31例，采用第二代双源CT设备进行检查，准直为2×128×0.6 mm，旋转时间为0.28 s。两组均采用双源高心率心电图门控模式进行检查，螺距为3.0，管电压为100 kV，采用参考管电流288 mA的自动管电流调制。使用45 ml对比剂团注，流速为4.5 ml/s，随后以5.0 ml/s的流速注入50 ml生理盐水冲管。当主动脉起始部触发阈值达到100 HU后，采用团注追踪技术自动启动CTA扫描。两组的启动延迟均设置为6 s。评估两组的有效剂量（ED）、信噪比（SNR）、对比噪声比（CNR）及主观诊断质量。结果 第1组的平均ED[（3.15±0.86）mSv]比第2组[（3.91±0.60）mSv]低19.44%（t=-3.989，P=0.000）。两组在SNR或CNR方面差异均无统计学意义（均P>0.05）。主观诊断质量值在两组间也无显著差异[（1.39±0.50）分对（1.45±0.51）分；W=814.5，P=0.651]。结论 与第二代双源CT扫描仪相比，第三代双源CT扫描仪在全主动脉CTA中可显著降低辐射剂量，且不影响图像质量。
