低kVp扫描技术在肺静脉及左心房多层螺旋CT血管造影中的应用价值  

The applied value of low kVp scan in pulmoanary veins and left atrium MSCTA

作　　者：周忠洁[1] 赵晓君[1] 陈梅魁[1] 许崇永[1] 蔡志胜[1] 

机构地区：[1]温州医科大学附属第二医院放射科,浙江温州325027

出　　处：《温州医学院学报》2013年第11期727-730,共4页Journal of Wenzhou Medical College

基　　金：温州市科技局科研基金资助项目(Y20110117)

摘　　要：目的:探讨低kVp扫描技术在肺静脉及左心房多层螺旋CT血管造影(MSCTA)检查中的应用价值。方法:搜集临床行肺静脉及左心房MSCTA检查的中等体型患者40例,随机分成A、B两组,每组各20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(CTDI vol)及剂量长度乘积(DLP),计算有效剂量E值。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;双盲法主观评价肺静脉及左心房后重组图像,评判标准依据肺静脉及左心房清晰度、空间分辨率、噪声及伪影,将图像分为优、良、差3个等级。对两组间的L、CTDI vol、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组的L值分别为(26.52±1.36)cm和(26.33±1.21)cm,两组比较差异无统计学意义(P=0.633),但A组和B组的CTDI vol分别为(19.40±0)mGy和(8.40±0)mGy,DLP为(514.49±26.29)mGy·cm和(221.13±10.13)mGy·cm,E值为(8.75±0.45)mSv和(3.76±0.17)mSv,两组比较差异均有统计学意义(P=0.000),B组比A组分别降低了56.70%、57.02%、57.03%。A组和B组SNR分别为27.73±1.91和24.00±2.33(P=0.000),CNR分别为23.25±1.89和20.86±2.15,两组比较差异也均有统计学意义(P=0.000),B组比A组分别降低了13.45%、10.28%。A组和B组的图像质量主观评判诊断满意率均达100%,两组比较差异无统计学意义(P>0.05)。结论:肺静脉及左心房MSCTA检查使用低kVp扫描技术可以较大幅度降低辐射剂量,避免或降低了因辐射效应可能产生的不良后果,具有较大的临床应用价值。Objective： To explore the applied value of low kVp scan in pulmonary veins and left atrium multi-slice computed tomography angiography（MSCTA） and to reduce the radiation dose. Methods： Forty middle-sized patients were collected and randomly divided into group A and group B averagely. All cases under- went pulmonary veins and left atrium MSCTA. The routine KVP and low KVP CT scan were respectively used in group A and B. The CT scan length（L）, volume CT dose index（CTDI vol） and dose length product（DLP） of two groups were recorded automatically, and the effective dose（ED） was measured. The signal to noise ratio（SNR） and the contrast to noise（CNR） of thoracic aorta at the level of the middle left atrium were measured to evaluate the image quality objectively. The post-processing image quality was graded as excellent, good and poor according to the articulation of the pulmonary veins and the left atrium, spatial resolution, noise and artifact. The image quality was evaluated by two experienced radiologists with the double-blind method. The L value, CTDI vol, DLP, ED, SNR and CNR were evaluated by t test. The subjective evaluation of image quality was analyzed with chi- square test. Results： The L value of group A and group B was（26.52±1.36） cm and（26.33±1.21） cm, respectively. The difference of L value in two groups had no statistical significance（P=0.633）. The CTDI vol（mGy） of group A and group B were（19.40 ± 0） mGy and（8.40 ± 0） mGy, respectively. The DLP（mGy·cm） of the two groups was（514.49 ± 26.29） mGy·cm and（221.13 ± 10.13） mGy·cm. The ED of the two groups was（8.75 ± 0.45） mSv and（3.76 ± 0.17） mSv, respectively. The difference in group A and group B had statistical significance（P=0.000）. The CTDI vol（mGy）, DLP（mGy·cm） and ED of group B decreased 56.70%, 57.02% and 57.03% than that of group A, respectively. The SNR and CNR in group A and group B were 27.73 ± 1.91, 23.25 ± 1.89 and 20.86 ± 2.15, 20.86 ± 2.15, r

关 键 词：肺静脉 左心房 辐射剂量 体层摄影术 X线计算机 

分 类 号：R54[医药卫生—心血管疾病]