小儿心脏大血管CTA低kVp扫描的应用价值  

The application value of lower kVp scanning of CTA in heart and great vessels of children

作　　者：陈伟慧[1] 郑文龙 程建敏[1] 吴爱琴[1] 

机构地区：[1]温州医学院附属第二医院放射科,浙江温州325000 [2]浙江省温州市中心医院放射科,浙江温州325000

出　　处：《医学影像学杂志》2013年第11期1691-1694,共4页Journal of Medical Imaging

基　　金：浙江省温州市科技计划项目(Y20090411)

摘　　要：目的探讨低kVp扫描技术在小儿心脏大血管CTA检查中降低辐射剂量的价值。方法选取小儿先天性心脏病CTA检查病例39例分为两组,A组24例,B组15例。A组使用常规kVp 120,B组使用低kVp 90。记录两组病例扫描时机器自动显示的扫描长度(L)、容积CT剂量指数(CTDIvol)及剂量长度乘积(DLP)。测量并计算左心房中部水平胸主动脉信噪比(SNR)、对比噪声比(CNR)以客观评价图像质量;双盲法主观评价心脏大血管后重组图像对肺动脉六分支的显示情况并给予优、良、差分级。对L、CTDIvol、DLP、E值、SNR及CNR进行t检验,主观图像质量评价采用x2检验。结果 A组和B组L分别为(10.40±1.97)cm和(9.54±1.72)cm,两组比较无统计学差异(P=0.169)。A组和B组的CTDIvol分别为(11.6±0)mGy和(5.0±0)mGy,DLP为(120.67±22.55)mGy·cm和(47.68±8.61)mGy·cm,两组比较均有统计学差异(P<0.0001),B组比A组分别降低56.9%、60.5%。A组和B组SNR分别为(41.86±12.05)和(42.11±7.83)(P=0.944),CNR分别为(33.15±10.82)和(33.75±6.76)(P=0.850),两组比较无统计学差异。A组和B组的图像质量主观评判诊断满意率均达100%,统计学比较无差异。结论小儿心脏大血管CTA检查使用低kVp扫描技术可以较大幅度降低辐射剂量,且不影响图像质量,具有较大的临床应用价值。Objective To investigate the value of lower kVp scanning technique of CTA reducing radiation dose in heart and great vessels of children. Methods 39 cases of CTA examination in congenital heart disease were included in the study and divided into A group （n=24） and B group （n= 15）. 120 kVp of routine-dose was used in A group while 90 kVp of low-dose in B group. Scan length （L）, volume computed tomography dose index （CTDIvol） and dose length product （DLP） automatically displayed in machine for all cases were respectively recorded while scanning. The image quality was objectively evaluated by signal-noise ratio （SNR） and contrast-to-noise ratio （CNR） of tissues measured and calculated in the thoracic aorta of middle level of the left atrium. The image quality of post processing of heart and great vessels displa- ying six branch of pulmonary artery was subjectively judged by double blind method and classified into three scale of excel- lent, good and poor. The results of L, CTDIvol, DLP, E, SNR and CNR were compared by t test and subjective judge- ment of image quality by X2 test. Results The L value of A and B group was respectively （10.40_--＋ 1.97） cm And （9.54~ 1.72） cm, and it had no statistical difference in two groups （ P =0. 169）. The CTDIvol of A and B group was respectively （11.6＋0） mGyand （5.0~0） mGy, DLPwas （120.67~22.55） mGy. cmand （47.68~8.61） mGy. cm. They all had statistical difference in two groups （ P d0. 0001）, and the B group reduced respectively 56. 9%, 60. 50/00 than the A group. The SNR of A and B group was respectively （41.86：t： 12.05） and （42. 11 q- 7.83） mm （ P = 0. 944）, and CNR was （33.15＋10.82） and （33.75-4-6.76） （ P =0. 850）. It had no statistical difference in two groups. In subjective judg- ment of image quality, the satisfaction rate of two groups was all 100.00~, and it had no statistical significance. Conclu- sion The CTA examination in heart and great vassels of children using lower kVp sca

关 键 词：儿童 辐射剂量 体层摄影术 X线计算机 

分 类 号：R541[医药卫生—心血管疾病] R814.42[医药卫生—内科学]