基于μMRI生物力学建模评估股骨近端微结构力学行为  

Evaluation of Microstructure Mechanical Behavior of Proximal Femur Based onμMRI Biomechanical Modeling

作　　者：霍晨晨 杨海胜 HUO Chenchen;YANG Haisheng(Department of Biomedical Engineering,Beijing University of Technology,Beijing 100124,China)

机构地区：[1]北京工业大学生物医学工程系,北京100124

出　　处：《医用生物力学》2024年第5期866-872,共7页Journal of Medical Biomechanics

基　　金：北京市自然科学基金项目(L232058)。

摘　　要：目的建立并验证一种基于显微磁共振成像(micro-magnetic resonance imaging,μMRI)和微结构分割无创评估股骨近端微观力学行为的生物力学建模方法。方法首先,对股骨样本进行μMRI扫描,基于分区域图像处理的方法分割骨微结构,建立μMRI微有限元模型(μMRI模型),模拟侧向跌倒姿态进行有限元分析,计算应力和应变。其次,借助显微CT(μCT),验证μMRI图像分割骨微结构的准确性;基于μCT构建有限元模型(μCT模型),验证μMRI模型计算结果的准确性。最后,通过模拟侧向跌倒的离体力学加载实验和应变片测量,验证μMRI模型计算骨表面应变的准确性。结果μMRI与μCT模型计算得到的骨微结构参数BV/TV显著相关(r=0.89,P<0.05),μMRI模型和μCT模型计算得到的最大和最小主应力/主应变百分位数高度相关(R^(2)>0.9)。μMRI模型计算得到的应变与力学实验测量的应变高度相关(R^(2)=0.82)。结论基于μMRI分割骨微结构建立的股骨近端微有限元模型可较为准确地表征股骨近端微观力学行为,研究结果为在体无创评估髋部股骨微结构退变和骨质疏松性骨折风险提供了重要工具。Objective To establish and validate a biomechanical modeling method based on micro-magnetic resonance imaging(μMRI)and microstructure segmentation for noninvasively assessing microstructure behavior of the proximal femur.Methods Firstly,μMRI images were obtained from the femoral samples,and bone microstructures were segmented through regionized image processing to create theμMRI finite element model(μMRI model).Finite element analysis was performed utilizing a lateral fall posture simulation,and stress and strain were calculated.Secondly,the accuracy ofμMRI image segmentation of bone microstructure was verified using micro-computed tomography(μCT),and the accuracy ofμMRI model calculation result was verified using a finite element model constructed based onμCT(μCT model).Finally,the accuracy of bone surface strain calculated byμMRI model was verified through in vitro mechanical loading experiments simulating lateral falls and strain gauge measurements.Results The bone microstructure parameters BV/TV calculated byμMRI model andμCT model were significantly correlated(r=0.89,P<0.05).The maximum and minimum principal stress/principal strain percentiles calculated byμMRI model andμCT model were highly correlated(R^(2)>0.9).The strain calculated byμMRI-FEM was highly correlated with the strain measured by mechanical experiments(R^(2)=0.82).Conclusions The micro finite element model based onμMRI segmentation of bone microstructure can accuratelycharacterize the micro-mechanical behavior of the proximal femur.This study provides an important tool for noninvasiveassessment of hip femur microstructure degeneration and osteoporosis fracture risk in vivo.

关 键 词：显微磁共振成像 微计算机断层扫描 有限元分析 股骨 骨微结构 

分 类 号：R318.01[医药卫生—生物医学工程]