基于体素内不相干运动扩散加权成像的虚拟磁共振弹性成像在髌下脂肪垫中的可重复性分析  

Evaluation of the reproducibility of virtual magnetic resonance elastography based on intravoxelincoherent motion diffusion weighted imaging in the infrapatellar fat pad

作　　者：樊秋菊 谭辉 郭炎兵[1] 申利 于楠 于勇 FAN Qiuju;TAN Hui;GUO Yanbing;SHEN Li;YU Nan;YU Yong(Department of Radiology,Affiliated Hospital of Shaanxi University of Chinese Medicine,Xianyang 712000,China;The First Clinical Medicine College of Lanzhou University,Lanzhou 730000,China)

机构地区：[1]陕西中医药大学附属医院影像科,咸阳712000 [2]兰州大学第一临床医学院,兰州730000

出　　处：《磁共振成像》2025年第1期152-157,共6页Chinese Journal of Magnetic Resonance Imaging

基　　金：陕西省重点研发计划一般项目(编号:2023-YBSF-020);陕西省教育厅一般专项科研计划(编号:22JK0356)。

摘　　要：目的探讨基于体素内不相干运动扩散加权成像(intravoxel incoherent motion diffusion weighted imaging,IVIM-DWI)的虚拟磁共振弹性成像(virtual magnetic resonance elastography,vMRE)测量髌下脂肪垫(infrapatellar fat pad,IPFP)硬度的可重复性。材料与方法共50名受试者接受了两次使用10个b值的IVIM-DWI检查,检查间隔为30~60 min,采用18通道膝关节线圈。从两组不同的b值(200~800 s/mm^(2)和200~1500 s/mm^(2))中计算出移位表观扩散系数(shift apparent diffusion coefficient,sADC),随后转换为基于IVIM-DWI的虚拟剪切模量(μdiff_800和μdiff_1500)。两名观察者独立地在v MRE硬度图上勾勒出整个IPFP的感兴趣区(region of interest,ROI),以获得μdiff的平均值和标准差(standard deviation,SD)。使用组内相关系数(intra-class correlation coefficient,ICC)、变异系数(coefficient of variation,CoV)和Bland-Altman一致性界限(limits of agreement,LoA)评估短期重测可重复性、观察者内和观察者间一致性。结果μdiff_1500的平均值和SD值的观察者内和观察者间一致性优异(ICC≥0.90,P<0.001),SD值观察者内Co V>10%。μdiff_800平均值的观察者内和观察者间ICC分别为0.926和0.910(P<0.001),而μdiff_800的SD值的ICC分别为0.841和0.855(P<0.001),所有Co V>10%。与μdiff_800相比(ICC=0.886;Co V=13.7%),μdiff_1500的平均值重测可重复性优异(ICC=0.932;Co V=7.5%)。μdiff_1500的两次扫描间的平均偏差及SD为-0.01(0.37),而μdiff_800的两次扫描间的平均偏差及SD为0.05(0.79);μdiff_1500的95%LoA为-0.88~0.87,而μdiff_800的95%LoA为-0.63~0.73。结论基于IVIM-DWI的v MRE在评估IPFP组织弹性方面具有显著的潜力,b值组合为200~1500 s/mm^(2)所拟合的虚拟弹性值具有更好的观察者内、观察者间一致性和短期重测可重复性。Objective:To explore the reproducibility of intravoxel incoherent motion diffusion weighted imaging(IVIM-DWI)based virtual magnetic resonance elastography(vMRE)in measuring the stiffness of infrapatellar fat pad(IPFP).Materials and Methods:A total of 50 subjects underwent two IVIM-DWI examinations utilizing 10 b-values,with intervals of 30 to 60 minutes,employing an 18-channel knee coil.The shift apparent diffusion coefficient(sADC)was calculated from two different b-values(200 to 800 s/mm^(2)and 200 to 1500 s/mm^(2)),which were subsequently converted into virtual shear moduli based on IVIM-DWI MRI(μdiff_800 andμdiff_1500).Two readers independently outlined the entire IPFP region of interest(ROI)on the vMRE stiffness map to obtain the mean and standard deviation(SD)ofμdiff.The intra-class correlation coefficient(ICC),coefficient of variation(CoV),and the limits of agreement(LoA)of Bland-Altmanwere utilized to evaluate short-term test-retest repeatability,as well as intra-observer and inter-observer consistency.Results:The average and SD values ofμdiff_1500 demonstrated excellent intra-and inter-observer consistency,with an ICC of≥0.90(P<0.001).Notably,the intra-observer CoV for the SD values was greater than 10%.The intra and inter-observer ICC values for the average ofμdiff_800 were 0.926 and 0.910,respectively(P<0.001),while the ICC values for the SD ofμdiff_800 were 0.841 and 0.855,respectively(P<0.001),with all CoV exceeding 10%.In comparison toμdiff_800(ICC=0.886;CoV=13.7%),the average ofμdiff_1500 exhibited excellent repeatability upon retesting(ICC=0.932;CoV=7.5%).The average deviation(SD)between two scans ofμdiff_1500 was−0.01(0.37),whereas forμdiff_800,it was 0.05(0.79).The 95%LoA forμdiff_1500 ranged from−0.88 to 0.87,while forμdiff_800,it ranged from−0.63 to 0.73.Conclusions:The findings suggest that the vMRE,utilizing IVIM-DWI,holds substantial promise for assessing the tissue elasticity of the IPFP.Furthermore,the virtual elasticity values derived from b-value combinations of 200

关 键 词：髌下脂肪垫 硬度 磁共振成像 体素内不相干运动 扩散加权成像 虚拟磁共振弹性成像 

分 类 号：R445.2[医药卫生—影像医学与核医学] R684.3[医药卫生—诊断学]