磁共振成像动态测量脊髓圆锥位置

背景:以往对成人脊髓圆锥末端位置的研究多限于尸体解剖且年代久远,因此有必要通过磁共振成像对国内人群的脊髓圆锥位置进行活体动态系列观察。目的:通过磁共振成像观察无脊柱脊髓畸形的脊髓圆锥位置的变化。设计:观察对比实验。单位:青岛市市立医院。对象:选择1993-10/2006-12青岛市市立医院放射科磁共振室收治的1199例因下腰痛进行腰椎磁共振成像检查的患者,男765例,女434例,年龄5～85岁,平均(46±14)岁。其中椎体转移性肿瘤或脊柱创伤276例,排除脊柱侧弯或先天性脊柱脊髓疾病患者。另选择30名健康志愿者到院健康体检者,男女各15名,年龄19～52岁,平均(32±8)岁。所有受试对象均对检测项目知情同意。方法:应用美国GE公司Signa1.5T磁共振成像机对1199例患者行腰椎磁共振扫描,自旋回波T1加权、正中矢状位像上观测脊髓圆锥末端的位置。根据其与相应椎体的上、中、下1/3及椎间盘的对应关系定位。另对30例健康志愿者进行了腰椎中立、过屈、过伸位脊髓圆锥末端的动态观察。主要观察指标:下腰痛患者脊髓圆锥末端的位置及健康志愿者不同脊髓体位圆锥末端的动态观察结果。结果:下腰痛患者1199例及30名健康志愿者均进入结果分析。①下腰痛患者脊髓圆锥末端的平均位置为L1的下1/3水平(范围:T12的中1/3～L3的上1/3),圆锥末端的位置呈正态分布,女性圆锥位置低于男性(t=18.127,P<0.01),各年龄段无差别(F=0.530,P>0.05)。②当脊椎过伸或过屈位时,圆锥位置相对于椎体后缘上下关系无变化,但过屈时略接近椎体后缘,过伸时略远离椎体后缘。结论:本组人群中脊髓圆锥末端的位置位于T12的中1/3～L3的上1/3,女性圆锥位置低于男性。

Dynamic determination of the location of conus medullaris by magnetic resonance imaging

BACKGROUND:Studies on the tip position of the conus medullaris in a population have been limited to autopsy and long ago. Therefore, it is necessary to dynamically study the position of conus medullaris (CM) in the Chinese population by magnetic resonance imaging (MRI).OBJECTIVE: To observe the variation in position of the CM in a living population without spinal deformity through MRI. DESIGN: A controlled observation.SETTING: Qingdao Municipal Hospital.PARTICIPANTS: Totally 1199 patients who complained of low back pain and underwent MRI examination in the Department of Radiology of Qingdao Municipal Hospital between October 1993 and December 2006 were recruited in this study. The involved patients, including 765 males and 434 females, were averaged (46±14)years ranging from 5 to 85 years old. Among them, 276 patients suffered from metastatic tumor on spinal vertebrae or trauma of spinal column. Patients with scoliosis or congenital diseases of spinal cord and spinal column were rejected. Another 30 volunteers were recruited via advertisement checked up in the Department of Radiology of Qingdao Municipal Hospital.All the volunteers, including 15 males and 15 females, were averaged (32±8)years, ranging from 19 to 52 years.Written informed consents of detected items were obtained from all the subjects.METHODS: Totally 1199 patients underwent lumbar vertebra MRI scanning by a GE Signa 1.5T supraconduction MRI machine. The tip position of the conus medullaris was observed by spin echo T1 weighted and median sagittal imaging.The MRI machine was located according to its corresponding relationship with vertebral body and intervertebral disc. All the volunteers were given the dynamic research conceming the tip of CM in middle, hyperflexion and hyperextension position.MAIN OUTCOME MEASURES: Dynamic observation of the location of tip of CM in the healthy volunteers and the patients who complained of low back pain.RESULTS: The above 1199 patients who complained of low back pain and 30 healthy volunteers participated in the final analysis. ①The mean conus position of the patients who complained of low back pain was the lower third of L1 (range: middle third of T12 to upper third of L3). The variation in conus positions followed a normal distribution. The conus position in female patients was significantly lower than that of male counterparts (t =18.127,P ＜ 0.01). No significant difference in conus position was seen with increasing age (F =0.530, P ＞ 0.05). ②The tip of the CM did not change in relation to the posterior edge of vertebrae when the spine was in hyperflexion or hyperextension position.However, it got close slightly to the posterior edge of vertebrae when in hyperflexion, and got away slightly from it when in hyperextension.CONCLUSION: The location of tip of CM of our group of population ranges from the middle third of T12 to the upper third of L3, and female population have a much lower conus position than that of male ones.