Seminars in musculoskeletal radiology
-
The diagnosis of a peripheral nerve tumor can often be suggested on imaging. Direct continuity with a neural structure or location along a typical nerve distribution, shape, and intrinsic magnetic resonance (MR) signal characteristics represent the most important signs in this regard. ⋯ This article reviews the MR imaging appearance, clinical and pathological features of schwannoma, localized neurofibroma, plexiform neurofibroma, intraneural perineurioma, fibrolipomatous hamartoma, nerve sheath ganglion, traumatic neuroma, malignant peripheral nerve sheath tumor, and secondary malignant neoplasms of peripheral nerves. Typical findings are illustrated on the basis of histologically confirmed cases.
-
Semin Musculoskelet Radiol · Nov 2010
ReviewEntrapment neuropathies I: upper limb (carpal tunnel excluded).
Several entrapment neuropathies of the upper extremity can cause hypoechoic swelling and nerve compression as seen at ultrasound. The ulnar nerve can be compressed at the cubital tunnel of the elbow and Guyon's canal at the wrist. ⋯ In addition to compression at the carpal tunnel, the median nerve may be compressed at the elbow, related to a supracondylar process or by the pronator teres. Knowledge of these key anatomical sites of potential nerve compression is essential for accurate diagnosis of entrapment neuropathies.
-
Semin Musculoskelet Radiol · Nov 2010
ReviewPeripheral nerves: ultrasound-guided interventional procedures.
Specific ultrasound (US)-guided interventional procedures on peripheral nerves are reviewed in this article including regional anesthesia, biopsy of neural lesions, and some injection therapies. For these procedures, US is the best modality to provide a safe imaging guidance because of its excellent spatial resolution and real-time capabilities. ⋯ The use of US-guided injections in specific clinical settings, such as the percutaneous treatment of carpal tunnel syndrome, Morton's and saphenous neuromas, painful stump neuromas, piriformis syndrome, and meralgia paresthetica are also illustrated here. US allows the clinician to inject drugs with little or no patient discomfort.
-
Semin Musculoskelet Radiol · Nov 2010
ReviewUltrasound and magnetic resonance imaging of the peripheral nerves: current techniques, promising directions, and open issues.
High-resolution ultrasound (US) and magnetic resonance (MR) imaging are the two imaging methods of choice for the study of peripheral nerves. The many advances that have been made in recent years, either by US or MR imaging, including diffusion tensor imaging and tractography, offer new perspectives for the assessment of many pathological processes affecting peripheral nerves such as entrapment syndromes, tumors and tumor-like lesions, and traumatic disorders. ⋯ US and MR imaging are complementary, each having advantages and disadvantages. Tractography is still emerging in the musculoskeletal field, particularly for the analysis of peripheral nerves, but this technique seems promising.
-
Semin Musculoskelet Radiol · Nov 2010
ReviewTraumatic neuropathies: spectrum of imaging findings and postoperative assessment.
Traumatic injury to peripheral nerves is a significant cause of morbidity and disability. Until reinnervation occurs, electrodiagnostic studies cannot differentiate severe axonotmetic lesions (Sunderland class 4) from complete nerve transection or neurotmesis (Sunderland class 5). This limitation is relevant clinically because in cases of neurotmesis an improved outcome may be achieved with an early surgical repair (within 1 week after trauma). ⋯ The role of diagnostic imaging in stretching injuries, contusion trauma, penetrating wounds, and after surgery is discussed. A multimodality diagnostic approach including physical examination, electrophysiology, and US and MR imaging allows an accurate evaluation of most peripheral nerves. Imaging assessment of peripheral nerves trauma is useful for the diagnosis, follow-up, and postoperative evaluation.