While there is good evidence that patients with severe CTS benefit from surgery, there is less evidence of a benefit for patients with mild to moderate disease. However, mild to moderate disease still accounts for important disability. Electrodiagnostic studies (EDS) have not been shown to accurately predict outcomes for patients with CTS. Recent advances in MR permit high-resolution neurographic imaging of the median nerve, and pilot data suggest that wrist MRI might be a better predictor of outcome than EDS. Thus, wrist MRI has the potential for playing a major role in the treatment of patients with CTS. We will test two main hypotheses: 1) that select patients with early, mild or moderate CTS benefit more from early surgery than with conservative therapy; and, 2) that wrist MRI accurately identifies those patients more likely to benefit from surgery. We will perform a randomized, controlled treatment trial nested within a prospective cohort as our study design.