The value of MRI in diagnosis of cubital tunnel syndrome / 实用放射学杂志

ABSTRACT

Objective To study the value of magnetic resonance imaging (MRI)in diagnosis of cubital tunnel syndrome (CuTS). Methods We studied the findings of electrophysiological examination and MRI in 30 elbows of 23 patients with CuTS and 15 elbows of 1 5 controls.We observed the motor conduction velocity (MCV),cross sectional area (CSA)and relative signal intensity (RSI)of the ulnar nerve acrossing the elbow at the point of largest size proximal to the entrapment point (CSA1 ,RSI1 )and the entrapment point (CSA2 ,RSI2 ).Then we calculated the ratio of CSA (CSAR=CSA1/CSA2 ),and the ratio of RSI (RSIR=RSI1/RSI2 ).Results The value of CSA1 and RSI1 was significantly greater than CSA2 ,RSI2 in the patient group (P<0.05).The value of CSA1 ,RSI1 , CSAR and RSIR in patients were significantly larger than that in controls (P<0.05).MCV was negatively correlated with CSA1 and CSAR in the patient group (r=-0.62,r=-0.53).There were no correlation between MCV and RSI1 ,RSIR in the patient group. The area under ROC curve of CSAR was the largest 0.94 (95% CI,0.83-1).The optimum cutoff point of CSAR was 1.83.The CSAR had sensitivity of 93.3% and specificity of 80% in diagnosis of CuTS.Conclusion MRI combined with the electrophysiologi-cal examination shows a high accuracy of locating the entrapment point of ulnar never lesion at the elbow.The CSAR of the ulnar nerve is the best MRI parameters in diagnosis of CuTS.