Tingling hand: magnetic resonance imaging of median nerve pathologies within the carpal tunnel.

Compressive neuropathy of the median nerve at the level of the carpal tunnel, known as carpal tunnel syndrome, is the most common entrapment neuropathy, affecting about 0.1-1% of the general population. Magnetic resonance reliably imaged the flexor retinaculum and carpal bones and thus defined the borders of the carpal tunnel. In all cases the median nerve was seen as an ovoid structure of moderate signal intensity and was easily distinguished from the flexor tendons of the hands running in the carpal tunnel. Magnetic resonance imaging (MRI) serves as an extremely useful tool for evaluation of primary nerve pathologies and for the assessment of space-occupying lesions leading to its compression. We present a pictorial review of the MRI findings in the multitude of pathologies implicated in the causation of carpal tunnel syndrome. All the images were obtained from the Department of Radiodiagnosis in our own institution.

Evaluation of peripheral nerve lesions with high-resolution ultrasonography and color Doppler.

PURPOSE: Traditionally, peripheral nerve lesions are diagnosed on the basis of clinical history, physical examination, and electrophysiological studies, and the role of imaging studies has been limited. The purpose of the study was to assess the usefulness of sonography in diagnosing peripheral nerve lesions. MATERIALS AND METHODS: Thirty adult patients with peripheral nerve lesion/s and 30 healthy adult volunteers were included in the study, and sonography of the relevant peripheral nerve/s was done. The mean cross-sectional area (CSA) of the involved nerves were compared using Student t-test. RESULTS: The study included patients with diabetic peripheral neuropathy (DPN), carpal tunnel syndrome, leprosy, peripheral nerve tumor, and peripheral nerve trauma. There was a significant increase in CSA of the median nerve and ulnar nerve in DPN patients, and of the median nerve within the carpal tunnel in carpal tunnel syndrome (P < 0.0001) as compared to age and sex-matched controls. Sonography showed significant thickening of both the ulnar and median nerves in patients with leprosy. On sonography, schwannoma and neurofibroma had a similar appearance and showed internal vascularity. In case of neural trauma, sonography allowed precise localization of the site and type of nerve injury. CONCLUSION: High-resolution sonography is useful in characterizing peripheral nerve lesions and can complement other diagnostic investigations such as the nerve conduction study. It is easily available and has the potential to become the first modality for the evaluation of focal peripheral nerve disorders.