激素性股骨头缺血坏死CT灌注成像

目的探讨激素性股骨头缺血坏死CT灌注成像变化及其与病理学相关性.方法 1～1.5年龄新西兰大耳白兔20只,包括实验组16只,每周两次臀肌注射甲基强的松龙8 mg/kg,在给药2、4、6、8周周末各处死4只;对照组:4只,在2、4、6、8周周末各处死1只.所有动物于处死前行CT灌注检查,经耳缘静脉注入欧乃派克350 mgI/ml,剂量2 ml/kg,速度1 ml/s.绘制感兴趣区时间-密度曲线(T-DC),计算Perfusion,PEI,PTT,MTT等指标.动物处死后取双侧股骨头制作病理切片,光镜观察.结果在给予激素后早期(2周后)股骨头内血流量开始下降,随着时间的延长下降更明显,股骨头内峰值增强值和平均通过时间仅在给药后4周有所下降.给药2周后股骨头空骨陷窝率明显增加,CT动态灌注各参数与空骨陷窝率没有统计学显著相关性.结论 MSCT灌注成像能够很好地发现股骨头血供的微循环变化,大量应用激素早期(2周后)股骨头内血流量开始减低,并随着激素应用时间延长,血流量逐渐减低至正常的60%,提示有股骨头缺血坏死.

Experimental investigation of CT perfusion on steroid-induced femoral head necrosis

Objective To explore CT perfusion imaging and pathological correlation of steroid-induced femoral head necrosis in adult rabbits.Methods Twenty rabbits of 1-1.5 years were divided into two groups,16 rabbits as group were injected 8 mg/kg Methylprednisolone twice a week,4 rabbits were used as control group.After rabbits were injected Omnipaque 350 mgI/ml through ear vein,dosage 2 ml/kg,rate 1 ml/s,CT perfusion were performed in all rabbits,then killed.Perfusion data of femoral head,including perfusion,PEI,PTT,MTT were calculated. All femoral heads were made paraffin section for pathological investigation.Results Two weeks after injection,blood flow of femoral head began decreasing,obviously with prolongation of injection; PEI and MTT decreased only 4 weeks after injection.Empty lacunae of bone tissue increased with prolongation of injection,but no statistical correlation with perfusion data could be found.Conclusion CT perfusion imaging can demonstrate hemodynamic status of femoral head,blood flow of femoral head began decreasing in early stage of injection,and obviously with prolongation of injection,which suggested development of osteonecrosis in the femoral head.