下颌骨CT扫描的优化  

Optimization of mandibular CT scanning

作　　者：周理余[1] 姜敏霞[1] 饶海英[1] 

机构地区：[1]浙江丽水市人民医院放射科,丽水323000

出　　处：《中华放射医学与防护杂志》2014年第11期870-871,880,共3页Chinese Journal of Radiological Medicine and Protection

摘　　要：目的 通过改变扫描位置优化下颌骨CT扫描方法降低辐射剂量，方法 50例下颌骨CT扫描的连续病例纳入本前瞻性对照研究,用随机数字表法分2组,各25例，分别进行体位优化法和常规法扫描,比较其图像质量、CT剂量加权指数（CTDIvol）、扫描范围长度（L）及剂量长度乘积（DLP），结果 体位优化法与常规法的下颌骨图像质量相同,两组的CTDIvol无明显差异,体位优化法扫描范围长度（L）和剂量长度乘积（DLP）比常规法分别下降20％（t=4.986,P＜0.05）和16％（￡=3.682,P＜0.05）,并避开了晶状体，结论 体位优化法下颌骨扫描能有效减少扫描长度和避开晶状体,降低有效辐射剂量。Objective To Optimize the mandibular CT scanning methods with changing the scanning position,to reduce the radiation dosage.Methods Totally 50 consecutive patients with mandibular CT examination were enrolled in the study and divided into position-optimized group and routine group （n =25,respectively） randomly.The image quality,volume CT-dose index （CTDIvol）,scanning length,and dose length product （DLP） were compared.Results There was no significant difference in subjective image quality and CTDIvol between two groups.But the scanning length and DLP in positionoptimized group were significantly reduced by about 20 % （t =4.986,P 〈 0.05） and 16% （t =3.682,P 〈0.05） compared with routine group.The lens were out of scanning field with the position-optimized protocol.Conclusions The scanning length would be efficiently reduced and the lens avoided with the position-optimized protocol,which would subsequently reduce the effective radiation dose.

关 键 词：扫描方法 图像质量 辐射防护 下颌骨 

分 类 号：R816.98[医药卫生—放射医学]