肺静脉及左心房多层螺旋CTA低剂量扫描技术研究  

Clinical application of multi-slice computed tomography angiography low-dose scan in pulmonary veins and left atrium

作　　者：周忠洁[1] 陈梅魁[1] 赵晓君[1] 吴爱琴[1] 蔡志胜[1] 

机构地区：[1]温州医学院附属第二医院放射科,325027

出　　处：《中华医学杂志》2013年第21期1637-1639,共3页National Medical Journal of China

基　　金：温州市科技计划项目（Y20110117）

摘　　要：目的探讨肺静脉及左心房多层螺旋cT血管造影（MSCTA）低剂量扫描技术，降低扫描辐射剂量。方法搜集2010年5月至2012年11月来温州医学院附属第二医院行肺静脉及左心房MSCTA检查的中等体型患者100例，随机分成5组，每组20例。管电流分别使用常规剂量250mAs，低剂量200、150、100及80mAs，记录扫描时机器自动显示的扫描长度（L）、容积CT剂量指数（CTDI训）及剂量长度乘积（DLP），计算有效剂量E值、左心房中部水平胸主动脉信噪比（SNR）和对比噪声比（CNR）以客观评价图像质量；采用双盲法主观评价肺静脉及左心房图像；结果进行统计学分析。结果（1）随着扫描剂量降低，CTDI_vol[5组数值分别为（19．4±0．0）、（15．5±0．0）、（11．6±0．0）、（7．8±0．0）、（6．2±0．0）mGy]、DLP[5组数值分别为（515±15）、（412±10）、（309±10）、（207±7）、（165±5）mGy＊cm]、E值[5组数值分别为（8．75±0．26）、（7．01±0．17）、（5．25±0．18）、（3．51±0．12）、（2．81±0．08）mSv]明显降低，差异有统计学意义。（2）80mAs组图像质量等级以良为主，100mAs及以上各组图像质量等级以优、良为主。随着mAs降低，图像质量将下降，SNR及CNR比较差异有统计学意义，但5组图像质量主观评判诊断满意率均达100％。结论在保证图像质量及满足临床诊断前提下，肺静脉及左心房MSCTA使用低剂量扫描技术可以较大幅度降低辐射剂量，具有较大的临床应用价值。Objective To investigate the clinical application of multi-slice computed tomography angiography （MSCTA） low-dose scan in pulmonary veins and left atrium and to reduce the radiation dose. Method 100 middle-sized patients underwent pulmonary veins and left atrium MSCTA were collected and randomly divided into five groups averagely. The tube current were 250 mAs （ conventional dose） , 200, 150, 100, and 80 mAs （low dose）, respectively. The CT scan length （L）, volume CT dose index （CTDIvol） and dose length product （DIP） of five 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 middle level of left atrium were measured to evaluate the image quality objectively. The image quality of pulmonary veins and left atrium MSCTA was evaluated by two experienced radiologists using double-blind method. The results were analyzed by statistics. Result （1）The CTDI_vol （mGy）, DLP （mGy ＊ cm） and ED decreased evidently with the scan dose reduced, and the difference had statistical significance. （2）The image quality was mainly excellent and good in 100 mAs and the above, and it was mainly good in 80 mAs group. The image quality decreased with mAs reduced. The difference of SNR and CNR within five groups had statistical significance. The satisfaction degree of subjective evaluation on image quality of the five groups was up to 100%. Conclusion On the premise that the image quality confirmed to the clinical diagnosis, the low dose scan in pulmonary veins and left atrium SCTA can obviously reduce radiation dose, and it had important clinical significance.

关 键 词：体层摄影术 螺旋计算机 肺静脉 辐射剂量 

分 类 号：R816[医药卫生—放射医学]