低剂量CT结肠成像的图像质量与辐射剂量评价  

Evaluation of Image Quality and Radiation Dose in Low Dose CT Colonography

作　　者：王天乐[1] 龚沈初[1] 陈海涛[1] 崔磊[1] 崔海燕[1] 唐军华[1] 

机构地区：[1]南通大学第二附属医院影像科,南通226001

出　　处：《临床放射学杂志》2011年第11期1692-1696,共5页Journal of Clinical Radiology

基　　金：南通市科技局资助项目(编号:S10912)

摘　　要：目的评估低剂量CT结肠成像的图像质量,并统计其辐射剂量,探讨其临床应用价值。资料与方法对51例患者进行低剂量CT结肠成像。俯卧位扫描条件为120kV,30mAs;仰卧位扫描条件为120kV,50mAs。由两名医师盲法判定两种体位CT结肠成像的图像质量。记录每例患者接受CT低剂量结肠成像时的容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP),并估算出有效剂量。结果结肠的CT图像质量评分:仰卧位与俯卧位各评分点之间均无显著性差异(P>0.05),其图像质量较高;肠外实质器官的CT图像质量评分:仰卧位图像可以满足诊断需要,而俯卧位图像影响诊断和观察,两者各评分点之间有显著性差异(P<0.05)。辐射剂量测定:低剂量CT结肠成像的CTDIvol及DLP比常规腹部扫描降低了约70.7%。结论低剂量CT结肠成像降低了患者的辐射剂量,结肠及腹部实质器官的图像质量满足诊断要求。Objective To evaluate the image quality and radiation dose of low-dose CT colonography,investigate its value of clinical application.Materials and Methods 51 patients received low dose CT colonography.Supine（120 kV,50 mAs） and prone（120 kV,30 mAs） CT colonographic were perfomed.Two experienced radiologists evaluated the image quality of low dose CT colonography in two position with double blind method,and the image quality of colon and abdominal parenchymatous organ.CT dose index volume（CTDIvol）and dose length product（DLP） in supine combined prone position was recorded.Effective dose（E） was calculated.Results For image quality score of colon,there was no significant difference between the supine position and prone position（P 0.05）.High quality images for clinical diagnosis could be obtained.The differences of image quality score in abdominal parenchymatous organ between the supine position（50 mAs） and prone position（30 mAs） were statistically significant（P0.05）.By 30 mAs scan,the image quality influenced doctor to view and make diagnosis.Radiation dose：The general CTDIvol and DLP for low dose CT colonography was reduced by 70.7% than that of routine CT scanning in abdomen.Effective dose was 4.0-5.64 mSv.Conclusion Low dose CT colonography can be used to reduce radiation dose of patients and guarantee image quality of colon and abdominal parenchymatous organ.

关 键 词：低剂量 结肠 体层摄影术 X线计算机 图像质量 

分 类 号：R816.5[医药卫生—放射医学]