CAJ | 학술논문

目的研究80 kV管电压64排多层螺旋CT低辐射肺动脉成像的可行性.方法 64名志愿者随机分为2组.观察组35例采用80 kV管电压CT结合右头臂静脉作为团注追踪(bolus tracking)监测点进行肺动脉成像,对照组29例采用120 kV管电压,延迟时间采用团注测试峰值时间+0.7 s,进行肺动脉成像.测量容积CT剂量指数(CTDIvol)、剂量长度乘积(DLP),计算加权CT剂量指数(CTDIw)和有效剂量(E),测量肺动脉强化后CT值和背景噪声,计算信噪比(SNR)和对比噪声比(CNR).5分法对两组图像质量进行目测评分.对DIS、E、SNR、CNR进行t检验;采用MannWhitney U检验比较两组图像目测评分结果 .结果观察组DIS和E分别为(146.5±7.6)mGy·cm和(2.5±0.1)mSv,对照组DIS和E分别为(313.4±13.5)mGy·cm和(5.3±0.2)mSy,两者差异有统计学意义(P＜0.001),观察组的辐射剂量低于对照组.图像质量量化评价:观察组和对照组的SNR分别为32.6±3.6和31.35±2.0,差异无统计学意义(P=0.089).观察组和对照组CNR分别为28.5±3.4和27.6±1.1,差异无统计学意义(P=0.18).目测评分结果 :观察组为5分8例,4分26例,3分1例;对照组为5分5例,4分24例,差异无统计学意义(P=0.76).结论 80 kV 64排多层螺旋CT结合右头臂静脉作为bolus tracking监测点可以减少辐射剂量,同时不降低图像质量,是肺动脉造影的首选检查方法 .
목적 연구80 kV관전압64배다층라선CT저복사폐동맥성상적가행성.방법 64명지원자수궤분위2조.관찰조35례채용80 kV관전압CT결합우두비정맥작위단주추종(bolus tracking)감측점진행폐동맥성상,대조조29례채용120 kV관전압,연지시간채용단주측시봉치시간+0.7 s,진행폐동맥성상.측량용적CT제량지수(CTDIvol)、제량장도승적(DLP),계산가권CT제량지수(CTDIw)화유효제량(E),측량폐동맥강화후CT치화배경조성,계산신조비(SNR)화대비조성비(CNR).5분법대량조도상질량진행목측평분.대DIS、E、SNR、CNR진행t검험;채용MannWhitney U검험비교량조도상목측평분결과 .결과 관찰조DIS화E분별위(146.5±7.6)mGy·cm화(2.5±0.1)mSv,대조조DIS화E분별위(313.4±13.5)mGy·cm화(5.3±0.2)mSy,량자차이유통계학의의(P＜0.001),관찰조적복사제량저우대조조.도상질량양화평개:관찰조화대조조적SNR분별위32.6±3.6화31.35±2.0,차이무통계학의의(P=0.089).관찰조화대조조CNR분별위28.5±3.4화27.6±1.1,차이무통계학의의(P=0.18).목측평분결과 :관찰조위5분8례,4분26례,3분1례;대조조위5분5례,4분24례,차이무통계학의의(P=0.76).결론 80 kV 64배다층라선CT결합우두비정맥작위bolus tracking감측점가이감소복사제량,동시불강저도상질량,시폐동맥조영적수선검사방법 .
Objective To assess the feasibility of minimizing radiation doses using 80 kV 64-row muhidetector computed tomography on pulmonary angiography.Methods 64 volunteers were derided into 2 groups to undergo MDCT pulmonary angiography(collimation,64×0.625 mm;pitch,1.204).The observed group consisting of 35 patients were for pulmonary angiography with 80 kV voltage,300 mAs,0.75 s/roation.The control group consisting of 29 patients were for pulmonary angiography with the standard tube voltage (120 kV),200 mAs,0.5 s/roation and time delay using the peak time on bolus test added 0.7 s.Volume computed tomography dose index (CTDIvol),dose length product (DLP),pulmonary vessel enhancement and back noise were quantified.Signal-noise-ratio (SNR),contrast-to-noise-ratio (CNR),weighted computed tomography dose index (CTDIw) and effective dose (E) were calculated.Results of the two protocols were compared by using t test.Two radiologists used five-point scale to subjectively score arterial enhancement and depiction of small arterial detail.The scores were compared with Mann-Whitney U test.Results The 80 kV protocol had a significantly lower DLP and E than the 120 kV protocol[(146.5±7.6)mGy·cm vs(313.4±13.5)mGy·cm,P<0.001]and [(2.5m±0.1)mGy vs (5.3±0.2)mGy,P<0.001],respectively.The 80 kV protocol and the 120 kV protocol had identical SNR(32.6±3.6 vs 31.3±2.3;P=0.089) and CNR (28.5±3.4 vs 27.6±1.1;P=0.18).No significant difference was found between the two protocols on scores for arterial enhancement and depiction of small arterial detail ( P=0.76).Conclusions 80 kV 64 slices MDCT combined with right brachiocephalic vein as the monitoring site for bolus tracking could be the first choice of pulmonary angingraphy.It can reduce the radiation dose without sacrificing the image quality.