基于动态增强 MRI的膝骨关节炎患者的软骨下骨微灌注

摘要

目的：通过动态增强MRI技术观察不同退变程度膝骨关节炎患者不同负重位点软骨下骨的微灌注情况。方法选取诊断符合膝骨关节炎的患者35例，Kellgren－Lawrence分级（ K－L评分）Ⅲ～Ⅳ级的20例归为中重度骨关节炎组，K－L评分Ⅰ～Ⅱ级的15例归为轻度骨关节炎组；同时选取健康人15例归为健康组。所有研究对象接受3.0T MRI扫描仪检查，获取矢状位动态增强图像。在矢状位上分别于内外侧股骨远端、胫骨平台取4个相近规格的软骨下骨矩形兴趣区域，测量内容包括：兴趣区基础信号强度、强化率、最大斜率。结果3组基础信号强度差异均无统计学意义（P＞0.05）。与轻度骨关节炎组比较，中重度骨关节炎组内侧股骨远端最大斜率，内侧胫骨平台强化率、最大斜率，外侧胫骨平台最大斜率均显著增大（ P＜0.05）；与健康组比较，中重度骨关节炎组内侧股骨远端、内侧胫骨平台强化率、最大斜率及外侧胫骨平台最大斜率均显著增大（ P＜0.05）。结论随着骨关节炎程度的加重，膝关节软骨下骨表现为更高的微灌注状态，以机械载荷高的内侧股骨远端、胫骨平台更为明显，表现为强化率、最大斜率显著增大。%Objective To observe characteristics of subchondral micro-perfusion in patients with different stages of knee osteoarthritis at interesting regions of medial and lateral distal femur and tibia plateau.Methods Patients with knee osteoarthritis were enrolled and divided into two groups, severe osteoarthritis group with Kellgren-Lawrence ( K-L) grading at 3~4 (n=20) and mild osteoarthritis group with K-L grading at 1~2 (n=15), as well as 15 volunteers as control group.Dynamic contrast-enhanced MRI(DCE-MRI) was applied in all participants to acquire multiple se-quence images and sagittal dynamic contrast-enhanced images.The sagittal dynamic contrast enhanced sequence images and the intensity-time curve were attained with mean curve function.The 4 similar subchondral rectangle regions were selected at medial and lateral condyle of distal femur and tibia plateau.Basic signals, enhanced rate and maximum up-slope of these regions were measured and compared.Results There were no significantly statistical differences in basic signals among the 3 groups.Significant enhancements in the maximum upslope of medial distal femur and lateral tibia plateau, the maximum upslope and enhanced rate of the medial tibia plateau were observed in severe osteoarthritis group when compared with those in mild osteoarthritis group.Significant enhancements in the maximum upslope and enhanced rate of medial distal femur and tibia plateau, the maximum upslope of lateral tibia plateau were observed in severe osteoar-thritis group when compared with those in control group.Conclusion By the mean of DCE-MRI, we assume that the subchondral micro-perfusion is associated with the severity of osteoarthritis.