64排螺旋CT低剂量扫描技术在成人头颅检查中的应用  

Application of CT Low-Dose Scanning Technology of 64 Multidetector in the Examination of the Adult Head

作　　者：俞琴[1] 冉隆富[1] 秦菊[1] 韩林梅[1] 袁蓉[1] 丁洁[1] 万笃行 YU Qin RAN LongFu QIN Ju et al(Department of CT,The 7th Hospital of Chengdu, Sichuan 610021, P. R. China)

机构地区：[1]成都市第七人民医院CT室,610021 [2]GE公司CT应用培训部

出　　处：《临床放射学杂志》2017年第1期128-132,共5页Journal of Clinical Radiology

摘　　要：目的探讨64排螺旋CT低剂量扫描技术在成人头颅检查中的应用。方法选取常见病种患者90例,全部首次检查均为常规剂量检查(轴扫,400 mAs,CTDI_(vol)为76.71 mGy)。将第一次复查病例随机均分到三个轴扫低剂量扫描组中(240 mAs、200 mAs、160 mAs,CTDI_(vol)分别为46.02 mGy、38.35 mGy、30.68 mGy)。选取第二次复查病例40例,随机均分到4组螺旋扫描中。一组采用自动曝光控制技术(AEC),另三组采用固定管电流技术(CCC)(280 m A·0.4 s、250 m A·0.4 s、200 m A·0.4 s)。对CT剂量指数(CTDI_(vol))、剂量长度乘积(DLP)、有效剂量(ED)及图像主观评价进行统计学分析。结果螺旋AEC扫描的辐射剂量与轴扫400 mAs组接近。螺旋扫描112 mAs、100 mAs、80 mAs组的ED分别等同于轴扫中的240 mAs、200 mAs、160 mAs组。轴扫与螺旋CCC扫描的三组低剂量组与对照组相比,剂量下降率分别为40%、50%、60%。测量中脑、壳核及半卵圆中心白质区的噪声。160 mAs组的中脑噪声明显增大,达5.22±0.78;200 mAs及160 mAs组壳核及白质噪声组间无统计学差异(P>0.05),其余各组间均有统计学差异(P<0.05)。图像质量主观评价比较,240 mAs组评价优28例,良2例,200mAs组优15例,良15例,160 mAs组良28例,差2例。但在统计学上三组均无明显差异(P>0.05)。结论 240mAs组可设为常规扫描。200 mAs组可在患者复查中使用。160 mAs组可在轻度外伤及慢性头痛检查及短期颅内出血复查中使用。螺旋扫描(280 m A·0.4 s组)在需要快速扫描时使用。Objective To explore the application value of low-dose scan of 64 multidetector CT（ 64-MDCT） in the examination of the adult head. Methods 90 patients with common diseases were examined initially by CT with routine dose（ non spiral scan,400 mAs,CTDI_（vol）is 76. 71 mGy）. In the first reexamination the patients were randomly divided into three low dose groups（ 240 mAs、200 mAs 、160 mAs,CTDI_（vol）respectively is 46. 02 mGy、38. 35 mGy、30. 68 mGy）. In the second reexamination the patients were randomly divided into four spiral scan groups,a group of AEC and three groups of CCC（ 280 m A·0. 4 s、250 m A·0. 4 s、200 m A·0. 4 s）. Statistical analysis was performed on the CT dose index（ CTDI_（vol））,dose length product（ DLP）,effective dose（ ED） and subjective evaluation of the image. Results The radiation dose of the spiral AEC is close to the 400 mAs group of non spiral. ED of Spiral scanning were equivalent to the non spiral. Compared with the control group,the dose reduction rates of three groups of low dose were 40%,50% and 60%. Measure the noise of midbrain、putamen and white matter. The midbrain noise in 160 mAs group increased significantly,reaching 5. 22＋ 0. 78. In 200 mAs and 160 mAs group,putamen and white matter noise had no statistically significant difference（ P〈 0. 05）,the rest of the groups had significant difference（ P〈 0. 05）. In 240 mAs group,the image quality was judged to be excellent（ 28cases） and good（ 2 cases）,in 200 mAs group,excellent（ 15 cases） and good（ 15 cases）,in 160 mAs group,good（ 28 cases） and bad（ 2cases）,but there were no significant differences in the three groups（ P〈 0. 05）. Conclusion240 mAs group can be set as a routine scan. 200 mAs group can be used in case re-examined. The 160 mAs group can be used in mild trauma and chronic headache and reexamination of intracranial hemorrhage in the short term. Spiral scanning（ 280 m A·0. 4s group） can be used when a quick check is needed.

关 键 词：64排螺旋CT 成人头颅 低剂量扫描 

分 类 号：R816.1[医药卫生—放射医学]