CAJ | 학술논문

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80 mAs,记录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),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,CTDIvol[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)80 mAs组图像质量等级以良为主,100 mAs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.
목적 탐토폐정맥급좌심방다층라선CT혈관조영(MSCTA)저제량소묘기술,강저소묘복사제량.방법 수집2010년5월지2012년11월래온주의학원부속제이의원행폐정맥급좌심방MSCTA검사적중등체형환자100례,수궤분성5조,매조20례.관전류분별사용상규제량250mAs,저제량200、150、100급80 mAs,기록소묘시궤기자동현시적소묘장도(L)、용적CT제량지수(CTDIvol)급제량장도승적(DLP),계산유효제량E치、좌심방중부수평흉주동맥신조비(SNR)화대비조성비(CNR)이객관평개도상질량；채용쌍맹법주관평개폐정맥급좌심방도상；결과진행통계학분석.결과 (1)수착소묘제량강저,CTDIvol[5조수치분별위(19.4±0.0)、(15.5±0.0)、(11.6±0.0)、(7.8±0.0)、(6.2 ±0.0) mGy]、DLP[5조수치분별위(515±15)、(412±10)、(309±10)、(207 ±7)、(165 ±5)mGy* cm]、E치[5조수치분별위(8.75±0.26)、(7.01±0.17)、(5.25±0.18)、(3.51±0.12)、(2.81±0.08) mSv]명현강저,차이유통계학의의.(2)80 mAs조도상질량등급이량위주,100 mAs급이상각조도상질량등급이우、량위주.수착mAs강저,도상질량장하강,SNR급CNR비교차이유통계학의의,단5조도상질량주관평판진단만의솔균체100％.결론 재보증도상질량급만족림상진단전제하,폐정맥급좌심방MSCTA사용저제량소묘기술가이교대폭도강저복사제량,구유교대적림상응용개치.
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 (DLP) 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 CTDIvol (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.