Upper extremity peripheral neuropathies: role and impact of MR imaging on patient management.

To investigate the role of MR imaging (MRI) in the evaluation of peripheral nerve lesions of the upper extremities and to assess its impact on the patient management. Fifty-one patients with clinical evidence of radial, median, and/or ulnar nerve lesions and unclear or ambiguous clinical findings had MRI of the upper extremity at 1.5 T. MR images and clinical data were reviewed by two blinded radiologists and a group of three clinical experts, respectively, with regard to radial, median, and/or ulnar nerve, as well as muscle abnormalities. MRI and clinical findings were correlated using Spearman's (p) rank correlation test. The impact of MRI on patient management was assessed by the group of experts and ranked as "major," "moderate," or "no" impact. The correlation of MRI and clinical findings was moderate for the assessment of the median/radial nerve and muscles (p = 0.51/0.51/0.63, respectively) and weak for the ulnar nerve (p = 0.40). The impact of MRI on patient management was assessed as "major" in 24/51 (47%), "moderate" in 19/51 (37%), and "no" in 8/51 (16%) patients. MRI in patients with upper extremity peripheral neuropathies and unclear or ambiguous clinical findings substantially influences the patient management.