摘要
目的：探讨多层螺旋CT低剂量扫描在腰椎中的应用及其适宜的低剂量扫描条件。方法：选择60例30-65岁腰椎椎间盘退行性病变患者,随机分成A、B、C、D、E、F 6组,每组10例,采用不同的多层螺旋CT扫描参数进行扫描,并记录随机的容积CT剂量指数（volume CT dose index,CTDIvol）及剂量长度乘积（dose-length product,DLP）。采用自定标准盲式评估方法,对6组获得容积再现（volume rendering,VR）重组及Batch重组图像进行图像质量评分,由2位高年资主治医师依据空间分辨率、噪声、伪影及辐射剂量将图像分为好、中、差3级。结果：通过改变管电流（m A）、螺距及机架旋转速度,各组CTDIvol值、DLP值均存在明显统计学差异（P〈0.05）。相对于A组,B组CTDIvol值下降了14.29%,DLP值下降了12.64%;C组CTDIvol值下降了67.87%,DLP值下降了65%;D组CTDIvol值下降了62.49%,DLP值下降了58.45%;E组CTDIvol值下降了50%,DLP值下降了48%;F组CTDIvol值增加了24.86%,DLP值增加了29.7%。结论：正确调节管电流、螺距,可以在确保图像质量的同时,降低受检者所受辐射剂量。采用管电流350 m A、管电压120 k V、螺距1.375∶1,可降低58.45%的辐射剂量。
Objective To explore the application and conditions of low-dose multi-slice spiral CT scanning for lumbar disc diseases. Methods Totally 60 lumbar disc degeneration patients, aged from 30 to 65 years old, were divided equally into 6 groups of A, B, C, D, E and F. All the groups underwent CT scanning with different parameters, with the values of CTDIvoland DLP recorded. Blind evaluation with self-developed standard was carried out for the reconstructed image quality by VR and Batch. Two senior physicians graded the images as high, moderate and poor quality according to the resolution, noise, artifact and radiation dose. Results The values of CTDIvoland DLP were significantly different in the groups when changing the tube current, pitch and stand rotation speed, with P 0.05. When compared with the value of group A, CTDIvolhad the value decreased by 14.29% in group B, by 67.87% in group C, by 62.49% in group D, by 50%in group E and increased by 24.86% in group F; DLP had the value decreased by 12.64% in group B, 65% in group C,by 58.45% in group D, by 48% in group E and increased by 29.7%. Conclusion Radiation dose to the examinee can be reduced by appropriate adjustment of the tube current and pitch, with high quality image acquired, which can be reduced by 58.45% with 350 m A tube current, 120 k V tube voltage and 1.375∶1 pitch.
出处
《医疗卫生装备》
CAS
2014年第11期80-82,共3页
Chinese Medical Equipment Journal
关键词
多层螺旋CT
辐射剂量
腰椎
螺距
multi-slice spiral CT
radiation dose
lumbar vertebra
pitch
