CAJ | 학술논문

目的探讨多层螺旋CT(MSCT)低kV门静脉成像的可行性以及相关图像质量评价.方法连续31例门静脉成像患者纳入研究,以3.0 mL/s速率经肘正中静脉注射欧乃派克(350 mgI/ml)90 ml,使用256层CT(Philips Brilliance iCT)机型分别完成动脉期(120 kV,150 mAs)和门脉期(80 kV,120 mAs)扫描,记录两次扫描时的平均容积CT剂量指数(CTDIvol)和辐射剂量长度乘积(DLP),并计算有效辐射剂量(E).对门脉期数据采用4组不同滤波函数进行回顾性重建:A组,滤过反投影(FBP)+平滑函数;B组,FBP+标准函数;C组,迭代4(iDose4)+标准函数;D组,迭代6(iDose4)+标准函数.在工作站上分别完成门脉血管重建的最大密度投影(MIP)、容积重建(VR)和多平面投影重建(MPR)显示,并在门脉分支中心层面分别测量腹主动脉、门脉、肝右叶实质3个结构的CT值和图像噪声(SD)值.由2位资深放射科医生和1位CT技师共同评价门脉图像质量.结果门脉期扫描(低剂量)的DLP与E分别是(81.23±7.46)mGy·cm和(1.22±0.11)mSv,均明显低于动脉期(常规剂量)的(353.45±31.46)mGy·cm和(5.30±0.47)mSv(F=2197.23,P＜0.05);各组间SD值有明显差异(F=54.364,P＜0.05),以D组(57.09±13.59)最小,B组(115.55±31.12)最大.所有4组门脉图像均符合诊断图像质量要求,C和D两组门脉显示优于A和B两组.结论 80 kV结合迭代算法的低剂量MSCT门脉成像是可行的.
목적 탐토다층라선CT(MSCT)저kV문정맥성상적가행성이급상관도상질량평개.방법 련속31례문정맥성상환자납입연구,이3.0 mL/s속솔경주정중정맥주사구내파극(350 mgI/ml)90 ml,사용256층CT(Philips Brilliance iCT)궤형분별완성동맥기(120 kV,150 mAs)화문맥기(80 kV,120 mAs)소묘,기록량차소묘시적평균용적CT제량지수(CTDIvol)화복사제량장도승적(DLP),병계산유효복사제량(E).대문맥기수거채용4조불동려파함수진행회고성중건:A조,려과반투영(FBP)+평활함수;B조,FBP+표준함수;C조,질대4(iDose4)+표준함수;D조,질대6(iDose4)+표준함수.재공작참상분별완성문맥혈관중건적최대밀도투영(MIP)、용적중건(VR)화다평면투영중건(MPR)현시,병재문맥분지중심층면분별측량복주동맥、문맥、간우협실질3개결구적CT치화도상조성(SD)치.유2위자심방사과의생화1위CT기사공동평개문맥도상질량.결과 문맥기소묘(저제량)적DLP여E분별시(81.23±7.46)mGy·cm화(1.22±0.11)mSv,균명현저우동맥기(상규제량)적(353.45±31.46)mGy·cm화(5.30±0.47)mSv(F=2197.23,P＜0.05);각조간SD치유명현차이(F=54.364,P＜0.05),이D조(57.09±13.59)최소,B조(115.55±31.12)최대.소유4조문맥도상균부합진단도상질량요구,C화D량조문맥현시우우A화B량조.결론 80 kV결합질대산법적저제량MSCT문맥성상시가행적.
Objective To explore the feasibility and image quality of MSCT portal vein(PV)imaging with low-voltage.Methods The consecutive 31 patients were enrolled in the study.Ninety milliliter omnipaque(350 mg I/ml)with the rate of 3 ml/s was administrated through the median cubital vein.The arterial(120 kV,150 mAs)and PV(80 kV,120 mAs)phase scans were undertaken with a Philips Brilliance iCT scanner.The CTDIvol and DLP were stored and the effective dose(E)was calculated.Four PV image series were reconstructed with(A)FBP+smooth,(B)FBP+standard,(C)iDose4-4+standard,and(D)iDose4-6+standard algorithm.The maximum intensity projection,volume rendering and multiplanar reformation of portal vein were conducted on a workstation.The CT values of ROI of the aorta,PV,and liver parenchyma were measured,and the SD was considered as the noise.Two experienced radiologists and one technician together reviewed the images.Resnlts The DLP and E was significantly smaller in PV phases than that in arterial phases[low-dose:(81.23 ±7.46)mGy· cm,(1.22 ±0.11)mSv;routine dose:(353.45 ±31.46)mGy·cm,(5.30 ±0.47)mSv,F=2197.23,P＜0.05).The noises were different among the groups with that smallest in group D and largest in group B.All PV images were sufficient for diagnosis but those in the group C and D were better.Conclusions The hybrid low-dose MSCT PV imaging with 80 kV combined iterative method would be feasible.