多排螺旋CT正常肝脏低剂量扫描的应用评价

The Low Dose Multi Detector Row CT in Evaluating The Normal Uver

目的 评价正常肝脏低剂量平扫与常规剂量多排螺旋CT检查的放射剂量，探讨正常肝脏低剂量螺旋CT扫描的最佳条件及临床应用价值。方法将50例上腹部检查志愿者分为五组，每组10人的正常肝脏作为研究对象，分别用300mA、150mA、80mA、40mA、20mA进行螺旋CT平扫扫描，分别比较其扫描剂量产生的CT权重剂量指数（weighted CT doseindex，CTDIw）及剂量长度乘积（dose—length product，DLP）并作70检验。结果300mA常规剂量组与低剂量各组比较CTDIw值有显著性意义（P〈0．05），噪声与伪影40mA及20mA组明显高于其它组，选择5mm层厚、5mm间隔、120KV，80mA作为低剂量扫描的最佳条件。结论正常肝脏低剂量多排螺旋CT扫描的辐射剂量为常规剂量的24．07％，既可保证影像质量，又可降低患者的辐射剂量，具有较好的临床应用价值。

Objective To compare the radiation exposure delivered by low dose with with standard dose Multi Detector Row cr（MDCF） in examination of nor - contrast normal liver, and investigate scanning parameter. Mothods 50 cases, every group 10 patients and underwent MDCT scan,with 300 mA,150 mA,80 mA,40 mA,20 mA, weighted CT dose index（CTDIw）, doselength produet（DLP）produeed by the every scanning protocol were compared. Results There was significant difference about the data of CTDIw between the standard MSCT and the other groups（ P 〈 0.05）,noise and artifact of images in 40 mA,20 mA group were higher than ather groups, the best appropriate parameter was 5 mm collimation,5 mm interval, 120 K-V, 80 mA. Conclusion Radiation dose in normal liver produced by low dose CT was 24.07 %, its scanning not only can assure the image quality but can decrease the exposure to patients,that was widely used in clinical.