Intérêt de l'imagerie dans le diagnostic des plexopathies

Recent advances in magnetic resonance imaging (MRI) technology has improved vizualization of the peripheral nerve system, enabling further explorations of plexopathy beyond the physical examination and electrodiagnostic studies. High-resolution MRI is a method of choice, showing diffuse or focal enlargement, hyperintensity on T2-weighted images, altered fascicular patterns, enhancement after gadolinium injection or masses causing infiltration or compression, and signs of muscle denervation. Other techniques are complementary. Ultrasonography can depict a spectrum of lesions and can be coupled with dynamic manoeuvres to explore entrapment syndromes. Positron emission tomography (PET) can be helpful to differentiate between tumor recurrence and postradiation plexopathy. In posttraumatic brachial plexopathy, postmyelographic tomography and MRI are complementary. Traumatic injury, tumor formation, entrapment syndrome, and other conditions illustrate the different techniques available for imaging. Adequate imaging of the brachial and lombosacral plexuses is a useful aid for diagnosis, preoperative assessment and therapeutic planning and follow-up.