硬脊膜囊止点位置与止点上移征的MRI研究

Studies of normal position and high termination of lumbosacral dural sac on MRI

目的:测量正常成人硬脊膜囊止点位置,探讨其对硬脊膜外脂肪过多症的诊断价值。方法:随机选择200例（男女各100例）腰骶椎MRI片,在矢状面T1WI上测量硬脊膜囊止点与腰骶椎椎体的相对位置。再以测量结果为标准,前瞻性分析9例（男4例,女5例）硬脊膜囊止点上移者,及60例（男女各30例）硬脊膜囊止点在正常范围内的硬脊膜囊末端横断面形态。结果:全组硬脊膜囊止点中位数为S2椎体上缘平面,男性组为S2椎体中部平面,女性组为S1椎体下缘平面,女性硬脊膜囊止点位置比男性高（X2=73.138,P<0.01）。9例硬脊膜囊止点上移者,3例符合硬脊膜外脂肪过多症。60例硬脊膜囊止点正常者,未发现硬脊膜外脂肪过多症。结论:硬脊膜囊止点上移征对腰骶段硬脊膜外脂肪过多症具有较大诊断价值。

Objective:To investigate the end of the lumbosacral dural sac (ELSDS) in adult individuals so as to find the signs of the lumbosacral epidural lipomatosis on the sagittal MR T, WI. Methods:200 cases (100 males and 100 females) with the lumbosacral sagittal MR T1WI,were chosen randomly to survey the relative position between the ELSDS and the vertebral bodies. The shape of the lower spinal dural sac was studied prospectively on axial T] WI both in 9 cases with high termimation of the ELSDS and in the other 60 cases whose ELSDS were considered normal according to this study. Results: The median position of ELSDS was located at the superior level of S2 body in all patients,at the middle level of S, body in males and at the inferior level of S] body in females. The ELSDS of females is higher than that of males (X2 =73. 138,P< 0. 01). 3 cases out of 9 considered as high termination of the ELSDS according to this study were lumbar spinal lipomatosis on axial T1 WI,but there was no lipomatosis in 60 cases whose position of ELSDS was normal. Conclusion;The sign of high termination of ELSDS on MRI is valuable in the diagnosis of spinal epidural lipomatosis.