CT, myelography and CT-myelography in the evaluation of common cervicobrachial neuralgia.

The CT technique used to explore intervertebral discs and foramina is described, as are the CT signs of nucleus pulposus (NP) herniation and cervical degenerative lesions. CT with intravenous contrast injection is the most efficient and easiest method to diagnose a radicular compression of discal or degenerative origin. The advent of high-resolution contrast CT will probably make obsolete the use of contrast media. CT measures the width of the vertebral canal, but it does not evaluate the repercussions on the spinal cord of compression caused by NP herniation or osteophytosis: only CT-myelography or, better, MRI can make this evaluation. Conventional CT scans are sometimes inadequate when exploration is hampered by superimposition of the shoulders (C6-C7 and more often C7-T1), when the scanner is of poor quality or when it is misused. Myelography and CT-myelography can then be utilized to resolve the problem posed by C7 or C8 cervicobrachial neuralgia (CBN). CT makes it possible to exclude most of the causes of non-discal CBN in the extradural spaces (e.g. bone tumour, neurinoma, vertebral vascular malformation, paravertebral expansive process, apical lung tumour). The search for an intradural cause (extra- or intramedullary tumour) rests on myelography, CT-myelography and MRI.