Diagnosis of carpal tunnel syndrome: Electrodiagnostic and MR imaging evaluation

In patients who have clinically diagnosed CTS without symptoms or signs to suggest other disorders that can mimic CTS, it remains controversial as to whether performing NCSs is necessary or cost-effective [41]. Even less evidence exists regarding the cost-effectiveness of imaging for CTS. MR imaging reliably depicts normal carpal tunnel anatomy, including the median and ulnar nerves and their intraneural fascicular structure. It can also identify pathologic nerve compression and mass lesions, such as ganglion cysts, which compress nerves. Currently, MR imaging is probably most commonly used to image patients who have ambiguous electrodiagnostic studies and clinical examinations. MR diffusion-weighted imaging of peripheral nerves [42] might prove to be the most sensitive imaging sequence for the detection of early nerve dysfunction. Electrodiagnostic studies are likely to remain the pivotal diagnostic examination in patients with suspected CTS for the foreseeable future. With advances in imaging software and hardware, however, high-resolution MR imaging of peripheral nerves will become faster, cheaper, and likely more accurate, possibly paving the way for an expanded role in the diagnosis of this common syndrome.