自动管电流调制技术下不同探测器宽度与螺距对胸部CT检查辐射剂量及图像质量的影响

Effects of Different Detector Widths and Pitches on Chest Chest Computed Tomography Radiation Dose and Image Quality Under Automatic Tube Current Modulation Technology

目的:探究自动管电流调制技术下应用不同探测器的宽度与螺距对胸部CT辐射剂量及图像质量的影响。方法:选择2022年1月~2022年12月在本院行胸部CT检查的120例患者为研究对象,均应用飞利浦Brilliance iCT型128排(256层)CT进行检查,根据检查中不同探测器宽度、螺距参数进行分组,A组(探测器宽度40mm,螺距0.984)、B组(探测器宽度40mm,螺距1.375)、C组(探测器宽度80mm,螺距0.984)、D组(探测器宽度80mm,螺距1.375)各30例,均采用自动管电流调制技术,扫描范围均为肺尖部至肺底。比较各组主观、客观图像质量评分,并记录各组容积CT剂量指数、剂量-长度乘积以及各组扫描检查时间。结果:B组、D组主观图像质量评分、信噪比、对比噪声比明显优于A组、C组(P<0.05)。B组容积CT剂量指数、剂量-长度乘积显著低于D组(P<0.05)。D组扫描时间明显短于B组(P<0.05)。结论:与其他参数相比,在自动管电流调制技术下应用探测器宽度40mm、螺距1.375参数进行胸部CT扫描可获得良好的图像质量,并可减少辐射剂量。而应用探测器宽度80mm、螺距1.375能够缩短扫描时间,但其辐射剂量相对较大。

Objective:To explore the effect of different detector width and pitch on the radiation dose and image quality of chest computed tomography under automatic tube current modulation technique.Methods:120 cases of patients who underwent chest computed tomography examination in our hospital from January 2022 to December 2022 were selected as the research subjects.All patients were examined by Philips Brilliance iCT 128-slice(256-slice)CT.According to different detector width and pitch parameters in the inspection,group A(detector width 40mm,pitch 0.984),group B(detector width 40mm,pitch 1.375),group C(detector width 80mm,pitch 0.984),group D(detector width 80mm,pitch 1.375)were divided into 30 cases each.Automatic tube current modulation technique was used in CT examination,and the scanning range was from the tip of the lung to the bottom of the lung.The subjective and objective image quality scores of each group were compared,and the volume CT dose index,dose-length product and scanning inspection time of each group were recorded.Results:The subjective image quality score,signal-to-noise ratio,and contrast-to-noise ratio of group B and group D were significantly better than group A and group C(P<0.05).The volume CT dose index and dose-length product in group B were significantly lower than group D(P<0.05).The scanning time in group D was significantly shorter than that in group B(P<0.05).Conclusion:Compared with other parameters,applying detector width 40mm and pitch 1.375 parameters to chest computed tomography scanning under automatic tube current modulation technology can achieve good image quality and reduce radiation dose.The application of a detector with a width of 80mm and a pitch of 1.375 can shorten the scanning time,but its radiation dose is relatively large.