马尾沉降征在腰椎管狭窄症诊断中的价值

Diagnostic value of the nerve root sedimentation sign for lumbar spinal stenosis

目的 评价马尾沉降征在腰椎管狭窄症诊断中的价值并对其分型进行改良.方法 2012年11月至2013年11月因腰痛伴间歇性跛行而行MR检查的患者511例,选取椎管最狭窄层面的横断面MRI图像.按Schizas分型将患者分为A1、A2、A3、A4、B、C和D七型,测量各组的硬膜囊横截面积;对没有差异的组进行合并,制定新的马尾沉降征分型.比较马尾沉降征二分法、Schizas分型、新的马尾沉降征分型与硬膜囊横截面积分型法的相关性与一致性.比较新的分型方法各组患者的Oswestry功能障碍指数（Oswestry disability index,ODI）的差异.结果 Schizas分型A1型与A2型、A4型与B型、C型与D型组间硬膜囊横截面积的差异无统计学意义,合并后新的马尾沉降征分型分为阴性、a、b、c四型.马尾沉降征二分法与硬膜囊横截面积分型法的相关性为rs=0.579,一致性为κ=0.254;Schizas分型法与硬膜囊横截面积分型法的相关性为rs=0.718,一致性为κ=0.171;而新的马尾沉降征分型法与硬膜囊横截面积分型法的相关性为rs=0.722,一致性为κ=0.381,较前两种分型均提高.新的马尾沉降征分型各组ODI评分的差异有统计学意义（F=17.972,P=0.000）;其中c型组与其他各组比较差异均有统计学意义（P＜0.05）.结论 新的马尾沉降征分型与马尾沉降征二分法和Schizas分型比较,可以更加准确地反映MRI腰椎管狭窄程度,并在一定程度上反映患者主观临床症状的严重程度.

Objective To evaluate the diagnostic value of the nerve root sedimentation sign for lumbar spinal stenosis and improve morphological classification.Methods This is a retrospective radiologic study.From November 2012 to November 2013,511 patients who carried out MR examination due to backache together with intermittent claudication were selected.Cross-section MRI images at the narrowest layer of canalis spinalis were chosen.The patients were further divided into 7 groups,A1,A2,A3,A4,B,C,and D based on Schizas.The dural sac cross-sectional area （DSCA） of each group was measured.The groups without difference were merged.A new method to grade nerve root sedimentation was developed.Then,the correlation and consistency of nerve root sedimentation dichotomy,Schizas classification,new nerve root sedimentation classification and DSCA classification were compared.The differences of patients＇ Oswestry disability index （ODI） which adopted new classification method were compared.Results Results show there are no statistical significance between groups A1 and A2,groups A4 and B,or groups C and D in DSCA.After the merger,new nerve root sedimentation classification includes negative,a,b,and c.The correlation between nerve root sedimentation dichotomy and DSCA method is rs=0.579,and the consistency is κ=0.254.The correlation between new nerve root sedimentation classification method and DSCA method is rs=0.722,and the consistency is κ=0.381.The scores improve compared with the first two classification methods.ODI score difference of each group which adopted new nerve root sedimentation classification method has statistical signiftcance （F=17.972,P=0.000）.Pairwise comparison shows only group c differs significantly from other groups （P＜0.05）.Conclusion The new nerve root sedimentation classification method is more effective than nerve root sedimentation dichotomy and Schizas grading.It reflects the severity degree of patients＇clinical symptoms to some extent.