MR动态增强扫描评估髋部骨髓血流灌注的初步研究

Bone marrow perfusion of the hip evaluated with dynamic contrast-enhanced MRI:the preliminary results

目的观察FLASH序列T1WI动态增强扫描(DCE-MRI)髋部不同部位骨髓时间——信号强度曲线(TIC),分析其血流动力学特点及生理学意义。方法20例志愿者行髋部FLASH序列DCE-T1WI扫描,以双侧髋臼、干骺端及股骨头为研究对象,分别选择感兴趣区(ROI),绘制百分比TIC。读取TIC首次峰值(fE_(max))、最高信号强度(E_(max)),比较不同部位ROI各参数值的差异,分析其微循环血流灌注的特点。结果人体髋臼、干骺端及股骨头fE_(max)分别是(19.09±3.23、9.50±1.48、4.66±0.68)、E_(max)值分别是(25.30±3.64、19.27±1.38、10.31±1.20),三部位fE_(max)、E_(max)值差异均具有统计学意义(F值分别是283.96、235.96,P值均小于0.05)。结论FLASH序列DCE-T1WI可同时评估富血供红骨髓及乏血供黄骨髓微循环的血流灌注。股骨头低血流灌注可能是发生骨坏死的生理学易患因素之一。

Objective To prospectively assess bone marrow perfusion of the hip with dynamic magnetic resonance imaging of FLASH sequence T1WI and analyze hemodynamic characteristic and physiological significance in hip. Methods Dynamic contrast-enhanced （DCE） MRI of acetabulum, femoral head and metaphysis was performed in 20 volunteers. The percentage enhancement time-intensity curves （TIC） was drawn in region of interest （ROI） of different locations. The maximum percentage of enhancement at first past （fEmax） , maximum percentage of enhancement （Emax） were evaluated. The values of different ROI were compared in three locations. Results The fEmax and Emax varied widely in the subjects. The values of fEmax （19.09±3.23, 9. 50±1.48, 4.66±0.68） and Emax （25. 30±3. 64,19. 27±1.38,10.31±1.20） were significantly diffenent （P〈0. 05） from acetabulum, metaphysis and femoral head respectively. To contrast bone marrow in acetabulum and metaphysis, the results imply that there were low hemodynamic perfusion in femoral head. Conclusion It is satisfied to assess insufficiency hemodynamic perfusion of femoral head in DCE-MRI of FLASH sequence T1WI. The low hemodynamic perfusion is the potential risk factor of osteonecrosis in femoral head.