肘管尺神经脱位的剪切波弹性成像研究

Study on the ulnar nerve dislocation at cubital canal by shear wave elastography

目的采用高分辨率超声测量无症状肘管尺神经脱位组及对照组的尺神经最大直径及横截面积(cross-sectional area,CSA),应用剪切波弹性成像(shear wave elastography,SWE)评价两组尺神经的僵硬度,以探讨无症状肘管区脱位尺神经的高分辨率超声及SWE特征。方法由两位有经验的超声医师独立对38例无症状受试者(76侧肘)于屈伸肘关节时进行高频超声动态检查,判断其脱位与否,分为脱位组及对照组,并分别测量尺神经最大直径及横截面积,然后行SWE检查,分别测量剪切模量值。资料分析采用描述性统计及独立样本t检验,观察者一致性的评估采用组内相关系数(intraclass correlation coefficient,ICC)。结果15.8%(12/76)的受试对象可见尺神经脱位。脱位组肘管区尺神经最大直径(0.194±0.022)cm与对照组相应位置尺神经直径(0.181±0.023)cm比较,差异无统计学意义(t=1.888,P>0.05),脱位组肘管区尺神经CSA(0.064±0.009)cm^(2)及SWE(43.629±6.737)kPa与对照组相应位置尺神经CSA(0.050±0.008)cm^(2)及SWE(31.293±7.858)kPa比较,差异有统计学意义(P<0.001)。采用ICC评估观察者间对肘管尺神经最大直径、CSA及SWE值评价的一致性,结果显示一致性较好(ICC分别为0.941、0.819、0.843)。结论无症状受试者中存在尺神经脱位者其肘管尺神经的CSA及SWE值均显著增加,观察者一致性较好。高分辨率超声结合弹性成像可全面、定量地评估脱位尺神经的形态变化及力学性能,评估尺神经脱位并监测其进展。

Objective To investigate the characteristics of high-resolution ultrasonography and shear wave elastography(SWE)of asymptomatic ulnar nerve dislocation at cubital tunnel by measuring the maximum diameter and cross-sectional area(CSA)of ulnar nerve at cubital tunnel of asymptomatic dislocation group and control group with high-resolution ultrasound,and to evaluate the stiffness of ulnar nerve in two groups with SWE.Methods Thirty eight asymptomatic subjects(76 elbows)were examined with high-frequency ultrasonography during elbow flexion and extension dynamically by two experienced ultrasound doctors independently to determine whether there was a dislocation,according to which the patients were divided into dislocation group and control group.The maximum diameter and CSA were measured,and then the shear modulus was measured by SWE.The descriptive statistics and independent sample t-test were used for data analysis,and intraclass correlation coefficient(ICC)was used for observer consistency evaluation.Results Ulnar nerve dislocation was seen in 15.8%(12/76)of the subjects.There was no significant difference between the maximum diameter of ulnar nerve at cubital tunnel in dislocation group(0.194±0.022)cm and that at corresponding position in control group(0.181±0.023)cm(t=1.888,P>0.05).The CSA and SWE of ulnar nerve in elbow canal area in dislocation group were(0.064±0.009)cm^(2) and(43.629±6.737)kPa respectively,compared with CSA(0.050±0.008)cm^(2) and SWE(31.293±7.858)kPa of ulnar nerve in the control group.The differences between two groups were statistically significant(P<0.001).ICC was used to evaluate the consistency of the maximum diameter,CSA and SWE values of ulnar nerve at cubital tunnel among observers.The results showed that the consistency was good(ICC was 0.941,0.819 and 0.843,respectively).Conclusion In asymptomatic subjects with ulnar nerve dislocation,the CSA and SWE values of ulnar nerve at cubital tunnel are significantly increased,and the consistency of observers was good.High resolution ultrasonography combined with elastography can comprehensively and quantitatively evaluate the morphological changes and mechanical properties of the dislocated ulnar nerve,evaluate the status of ulnar nerve dislocation and monitor the progress.