Diagnostic Utility of MRI versus Nerve Conduction Studies in Carpal Tunnel Syndrome

Objective: To prospectively and quantifiably compare Magnetic Resonance Imaging (MRI) findings and nerve conduction study (NCS) findings in clinically diagnosed carpal tunnel syndrome (CTS).

Methods: A total of 27 wrist of 15 with CTS and 24 wrists of 13 healthy controls selected from the same cohort were studied in the present study. The protocol included NCS of the median and ulnar nerves (distal motor latency, sensory conduction velocity from the third fingers to the wrist for the median nerve); electrophysiological severity scale; and T2 intensity measurement of the nerve at place just 2 cm distal to it at the level of hamate bone. Relationships between NCS findings, severity of median nerve damage and T2 intensities were calculated.

Results: In comparison of age and gender matched two groups, we found that T2 signal intensities were higher in the patient group (p<0.001). There was no relationship between T2 signal intensity and NCS findings, gender, and the clinical findings such as provocative tests, the presence of motor or sensory symptoms except age.

Conclusion: In patients with idiopathic carpal tunnel syndrome, T2 intensity of median nerve measured by wrist MRI may be considered as a valuable indicator but it is not superior to electrophysiological studies in grading the severity of disease.