[Magnetic resonance imaging in paralysis of the upper limb of traumatic origin]

We have used magnetic resonance imaging in addition to the other imaging techniques for the examination of 31 patients with traumatic upper limb paralysis. The therapeutic indications of traumatic brachial plexus paralysis depend on the early and precise assessment of the lesions. Computed tomography with a contrast injection at a lumbar level opacifying the subarachnoid spaces provides a morphological study of the canal, spine and nerve roots and of container-contents relationships. In our experience, the diagnostic reliability for the detection of intraspinal radicular lesions is 86%. A study in all 3 spatial planes is possible with MRI with T1- and T2-weighted or gradient echo sequences. The reliability of the technique for the diagnosis of meningoceles in the detection of nerve root avulsion is similar to that of CT (85%). The excellent spatial resolution and natural high contrast allow following the nerve roots in their extraspinal course and determining the site of nerve trunk rupture (50%). The use of oblique and double-obliquity sections should yet improve these results. These first results lead us to proposing magnetic resonance imaging for the exploration of traumatic lesions of the brachial plexus. This nonagressive, more precise and more complete assessment of the lesions certainly has a significant influence on therapeutic choice.