能谱CT单能量成像技术对CT门静脉成像图像质量和肝脏体积测量的影响  

The influence of spectral CT monochromatic imaging technique on image quality and liver volume measurement in CT portal venography

作　　者：范勇 刘义军[1] 李贝贝 王诗耕 魏巍 童小雨 马志明 陈安良[1] 周宇靖 FAN Yong;LIU Yijun;LI Beibei;WANG Shigeng;WEI Wei;TONG Xiaoyu;MA Zhiming;CHEN Anliang;ZHOU Yujing(Department of Radiology,the First Affiliated Hospital of Dalian Medical University,Dalian,Liaoning Province 116011,China)

机构地区：[1]大连医科大学附属第一医院放射科,辽宁大连116011

出　　处：《实用放射学杂志》2024年第9期1536-1540,共5页Journal of Practical Radiology

摘　　要：目的 探讨能谱CT单能量成像技术对CT门静脉成像(CTPV)图像质量和肝脏体积测量的影响.方法 前瞻性选取行全腹部增强CT检查的患者120例,随机分为A、B 2组.A组(常规组,n=60):采用120 kVp,智能毫安(Smart mA)扫描,重建60%自适应统计迭代重建(ASIR-V)图像;B组(实验组,n=60):采用80/140 kVp瞬时切换,宝石能谱成像(GSI)Assist扫描,重建60%ASIR-V,75~50 keV(间隔5 keV)共6组图像,记为B1~B6组.在轴位图像测量门静脉、肝脏和竖脊肌的CT值、标准差(SD)值,并计算门静脉和肝脏的对比噪声比(CNR).应用Liver Segmentation软件对A、B 2组图像进行肝脏分割,记录肝脏自动分割和手动分割体积值(金标准),并计算体积差别率.由2名诊断医师采用5分法评估各组整体图像质量及肝脏自动分割情况.结果 在整体图像质量方面,B6组评分最高且优于A组(P<0.001),在肝脏分割方面,B3组评分最高且优于A组(P<0.001).随着keV的降低,B组门静脉和肝脏的CT值、SD值和CNR逐渐升高(P<0.05),B6组最高,高于A组(P<0.001);肝脏体积差别率先下降后上升的趋势,除B2、B3组与A组差异无统计学意义外,其余各组与A组差异均有统计学意义(P<O.001),其中B3组体积差别率最低.结论 能谱CT单能量成像技术对CTPV图像质量和肝脏体积测量有影响,其中50 keV图像显示门静脉最佳,65 keV图像软件自动测量的肝脏体积值最接近真实值.Objective To investigate the influence of spectral CT monochromatic imaging technique on image quality and liver vol-ume measurement in computed tomography portal venography(CTPV).Methods A total of 120 patients who underwent contrast-enhanced abdominal CT examination were prospectively selected and randomly divided into group A and group B.The group A(n=60)was scanned with conventional parameters such as 120 kVp,Smart mA mode,and image reconstruction of 60%adaptive statistical iterative reconstruction-Veo(ASIR-V);while the group B(n=60)was with instantaneous switching 80/140 kVp,gemstone spectral imaging(GSI)Assist mode,and image reconstruction of 60%ASIR-V.In group B,six subgroups of images from 75 to 50 keV(with 5 keV interval)were recorded as subgroups Bl to B6.On the axial images,the CT values and standard deviation(SD)values of por-tal vein,liver and erector spinae were measured,and then the contrast-to-noise ratio(CNR)of portal vein and liver were calculated.The Liver Segmentation software was used to segment the liver in groups A and B,the liver volumes by automatic segmentation and manual segmentation(golden standard)were recorded,and then the volume difference rate was calculated.The overall image quality and automatic liver segmentation results were evaluated by two radiologists using a 5-point scale.Results In terms of overall image quality,subgroup B6 achieved the highest score and was superior to group A(P<0.001).In terms of liver segmentation,subgroup B3 had the highest score and was superior to group A(P<0.001).With the decrease of keV,the CT values,SD values and CNR of portal vein and liver in group B were gradually increased(P<0.05),in which subgroup B6 was higher than that in group A(P<0.001).The volume difference rate initially decreased and then increased with the decrease of keV.Except for subgroups B2 and B3,the differences were statistically significant between other subgroups and group A(P<0.001),and the subgroup B3 had the lowest volume difference rate.Conclusion Spectral CT monochromati

关 键 词：门静脉 计算机体层成像 能谱成像 单能量图像 图像质量 肝脏 

分 类 号：R543.6[医药卫生—心血管疾病] R814.42[医药卫生—内科学] R322.47[医药卫生—临床医学]