腰椎间孔狭窄神经根卡压关键性数据与神经根分级关系MSCT负荷检查研究

Nerve Root Compression in Lumbar Intervertebral Foramen Stenosis:Critical Dimensional Values and the Grading of Nerve Root Using MSCT Axial Compression in Extension Examination

目的探讨多层螺旋CT（MSCT）轴向负荷（axial compression in extension,ACE）检查对下腰椎椎间孔（lumbar intervertebral foramen,LIF）狭窄神经根（nerve root,N）卡压关键性数据（critical dimensional,CD）：椎间盘后缘高度（h）、LIF高度（H）及其与N分级关系的影响和意义。资料与方法对30例伴腰腿痛或间歇性跛行患者行常规MSCT仰卧腰大肌放松体位（psoas-relaxed position,PRP）扫描后作ACE检查,分别在中央和旁中央矢状重组像测量h和H并观察N毗邻关系,将其分成0~Ⅲ4级,以Ⅱ~Ⅲ级及h和H均分别〈4 mm和15 mm临界值判断为LIF狭窄N卡压。结果 30例中PRP无椎间盘膨隆或突出（A组）36个平面CD显著高于伴椎间盘膨隆或突出（B组）54个相应平面;ACE后CD均减小,其中L4~5平面变化最大,L5~S1平面变化最小;降低到临界值以下A组5个平面,B组23个平面（t=6.88,P〈0.01）。A、B两组CD低于临界值Ⅱ~Ⅲ级N数PRP分别为：10根和28根（t=4.81,P〈0.05）;ACE分别为：18根和47根（t=5.43,P〈0.05）。B组N晋级19根显著多于A组8根（t=5.17,P〈0.05）。16例ACE后N功能缺陷症状加重,其中Ⅱ~Ⅲ级N晋级37根;CD降低到临界值以下17个平面,显著高于无临床症状加重者。结论 CD与N分级、椎间盘退变关系密切,ACE较PRP更进一步显示这种关系及其与临床症状的相关性。

Objective To discuss the effect of MSCT axial compression in extension（ACE） examination in evaluating the nerve root（N）compression in low lumbar intervertebral foramen（LIF） stenosis.Materials and Methods Thirty patients with low back pain and intermittent claudication were divided into 2 groups： normal disc（group A）and disc bulge or herniation（group B）.The patients underwent psoas-relaxed position（PRP） and ACE CT examinations.The critical dimensional（CD） of the nerve root,including posterior height of intervertebral disk（h）,the height of lumbar intervertebral foramen（H）were measured at central and paracentral sagittal plane.The relationship between N and LIF was divided into 0-Ⅲ grade.Ⅱ-Ⅲ grade and h4 mm and H15 mm were regarded as N compression of LIF stenosis.Results At PRP position,the CD values in group A were significantly higher than that in group B At ACE,CD values in both groups were reduced,especially in L4-5 plane.There were 5 planes in group A and 23 planes in group B,in which the h4 mm and H15 mm（t=6.88,P0.01）.At PRP position,the number of gradeⅡ-Ⅲ in group A and B were 10 and 28（t=4.81,P0.05）;At ACE,the number of gradeⅡ-Ⅲ in group A and B were 18 and 47,respectively（t=5.43,P0.05）.Compared with PRP,at ACE,The number of N rise in grade in group B was higher than that in group A（19 VS.8,t=5.17,P0.05）.At ACE,functional deficiency were aggravated in 16 cases.Conclusion CD value was closely related to N Grade and disc degeneration.Compared to PRP,ACE could further reveal the relationship of CD and clinical symptom.