Upper Abdomen Enhanced CT Low-dose Inspection In Patients Of Abdominal Circumference＜90cm: A Correlation Research Between Low-kilovoltage And Automatic Tube Current Modulation Technique And Image Quality

Objective To evaluate the correlation between low-kilovoltage and automatic tube current modulation(ATCM) technique and image quality in patients of abdominal circumference＜90cm performed by upper abdomen enhanced CT low-dose inspection. Materials and Methods One hundred patients of abdominal circumference＜90cm performed by upper abdomen enhanced CT inspection were randomly and averagely divided into conventional protocol(protocol A:120kv，ATCM，210mAs in arterial phase,190mAs in portal vein phase，n=50)and control protocol (protocol B:100kv，ATCM，250mAs in arterial phase，230mAs in portal vein phase，n=50). Background noise, singnal-to-noise ratio(SNR) of liver and pancreas, contrast-to-noise ratio(CNR) of liver-erector spinae and pancreas-erector spinae, CT attenuation values of abdominal aorta, SNR of abdominal aorta，CNR of abdominal aorta-erector spinae, CT volume dose index(CTDIvol), dose length product(DLP），and effective dose(ED) were measured and evaluated in the two protocols. The subjective evaluation of image quality includes axial images in arterial phase and portal vein phase, the three-dimensional branch score and the vision score of the celiac axis. The measurement data differences between the two protocols were compared with the independent-samples t test. The comparisons in the subjective evaluation of image quality were conducted with rank-sum test of ranked data by using SPSS13.0statistical software. Results Compared with use of the two protocols，background noise, the SNR of liver and pancreas, CT attenuation values of abdominal aorta, CTDIvol, DLP and ED were significant difference(P <0.05)，while SNR of abdominal aorta，CNR of abdominal aorta-erector spinae, CNR of liver-erector spinae and pancreas-erector spinae, the subjective evaluation of axial images，the three-dimensional branch score and the vision score of the celiac axis were not（P>0.05）. Conclusion Compared with use of the conventional protocol，use of control protocol can maintain the image quality，reduce radiation dose apparently, and increase the arteries display, which has great potential in clinical application.