兔颅脑低剂量CT扫描的图像质量评价及辐射防护意义  

The Evaluation of Radioprotection with Low Dose CT Scanning in Normal Rabbits Brain

作　　者：张树清[1] 龚沈初[1] 王天乐[1] 沈云霞[1] 崔磊[1] 

机构地区：[1]南通大学第二附属医院影像科,江苏南通226001

出　　处：《苏州大学学报（医学版）》2008年第2期215-217,共3页Suzhou University Journal of Medical Science

基　　金：南通市科技局资助项目(S5822)

摘　　要：目的研究兔颅脑扫描中降低管电流及改变螺距与图像质量的关系,探讨低剂量扫描的可行性及其辐射防护价值。方法将15只新西兰兔分别按以下6组条件行颅脑CT检查:200mAs、螺距1.0组;200mAs、螺距1.5组;110mAs、螺距1.0组;110mAs、螺距1.5组;70mAs、螺距1.0组;70mAs、螺距1.5组。由两名有经验的放射科医师以双盲的方法使用4分制评分,对6组图像中头部6个部位的解剖结构的清晰度进行质量评分,比较各组间图像质量及CT剂量加权指数(weightedCTdoseindex,CTDIW)的差异性。结果所有图像质量均能满足诊断要求。两名阅读者对6组图像中6个解剖部位的总评分差异均无统计学意义(P>0.05),对每个解剖部位的评分中,6组图像两两比较,差异均无统计学意义(均P>0.05)。而70mAs、螺距1.5组较200mAs、螺距1.0组的CTDIW降低约76.7%。结论应用70mAs低剂量颅脑CT扫描是可行的,图像质量能够满足临床要求,而辐射剂量大幅下降。Objective To determine wheather a lower radiation dose technique and various pitch could be used in CT of the rabbits＇ brain without jeopardizing the diagnostic accuracy of the images, and determine the evaluation of radioprotection with low dose CT scanning. Methods Fifteen rabbits underwent CT using 200 mAs,110 mAs or 70 mAs,and pitch 1.0 or 1.5. Anatomy details and the confidence level in reaching a diagnosis were evaluated by two radiologists in a double-blinded manner using a 4-point scoring system. The CTDIw of every group were compared. Results For both reader there was no statistically significant difference between 6 group total score of 1-6 anatomical detail and each of 6 anatomical detail although score for each of 6 anatomical detail. The CTDIw of 70 mAs,in pitch 1.5 group decreased about 76.7%. Conclusion Radiation dose reduction in brain CT is feasible in clinical use, and quality of images can be reserved. It plays an important role in radiation protection.

关 键 词：低剂量CT 兔 头颅 体层摄影术 X射线计算机 辐射防护 

分 类 号：R814.42[医药卫生—影像医学与核医学] R142[医药卫生—放射医学]