双源CT大螺距模式主动脉成像的可行性研究

Feasibility study of dual-source CT high-pitch aorta angiography

目的:利用双源CT的大螺距模式对主动脉全程扫描成像,对照评价其图像质量和有效辐射剂量,旨在研究双源CT大螺距模式行主动脉全程扫描的可行性。方法:将接受主动脉CT血管造影(CTA)的患者随机分为A、B两组,A组62例,B组58例。A组使用大螺距扫描模式,B组使用常规扫描模式;图像质量评价分客观和主观两种方法,客观评价包括图像噪声及信噪比,主观评价由2名放射科医生独立完成。辐射剂量统计使用设备自带的数据记录。结果:大螺距模式主观图像质量评分(2.66±0.51)较常规扫描组(2.14±0.47)高,差异有统计学意义(Z=-5.29,P<0.01);客观图像质量无明显差异;扫描时间大螺距模式组(1.61±0.23)s,比常规扫描组(6.52±1.41)s缩短,差异有统计学意义(t=-27.041,P<0.01);大螺距组有效辐射剂量(3.97±1.07)m Sv,对比常规扫描组(15.18±2.58)m Sv,差异有统计学意义(t=-20.22,P<0.01)。结论:大螺距模式主动脉全程扫描图像质量可以满足主动脉病变的诊断,具有扫描时间短、辐射剂量低及运动伪影少等优势,可替代主动脉检查常规扫描模式。

Objective： To investigate the feasibility, image quality and radiation dose for high-pitch dual-source CT angiography （CTA） of the whole aorta. Methods： Each group of 62 and 58 patients underwent CTA either on dual-source CT device with high-pitch mode with a pitch of 3.2（group A） or conventional single-source （group B）. Evaluate the image quality and radiation dose. Image quality of the aorta was independently assessed by two readers. Scanner-reported dose-length product values were used to estimate effective dose values. Results：Subjective scoring of image quality were significantly increased in the high-pitch examination protocol （2.66±0.51 vs.2.14±0.47, P〈0.01） for groups A and B. Objective scoring of image quality were not significantly different. The imaging length was not significantly different, but the imaging time was significantly shorter in the high-pitch group （1.61±0.23 vs.6.52±1.41s P〈0.01） for groups A and B. Radiation dose was lower. （3.97±1.07 mSv vs. 15.18±2.58 mSv, P〈0.01）. Conclusion：High-pitch dual-source CT angiography of the whole aorta is feasible in unselected patients. As a significant advantage over regular pitch protocols, shorter scan time, lower radiation dose and less motion artifacts is possible. this CT mode bears potential to become a standard CT protocol.