Diagnosis of nerve root compression. Myelography, computed tomography, and MRI.

Current technology and published studies support the preferential use of MRI in the diagnosis of cervical myelopathy. In cervical radiculopathy, data support the use of either contrast-enhanced CT or MRI. We prefer MRI as the initial diagnostic test because of the obvious advantage of its noninvasive nature. Similar to myelography, MRI permits visualization of the entire cervical canal and spinal cord. Unlike routine CT, MRI visualizes the spinal cord and nerve roots in two planes and is better in detecting unsuspected pathology at other cervical segmental levels. Because the quality of MRI scans in the cervical spine is subject to more variation than in the lumbar spine, anticipated pathology is sometimes not clearly visualized by cervical MRI. Under such circumstances, we obtain a water-soluble myelogram followed by contrast-enhanced CT. Because inaccurate radiographic diagnosis is one of the identifiable causes of poor outcome in surgical therapy for cervical spondylosis, accurate visualization of pathology in terms of its location, nature, and extent is imperative before performing decompressive cervical spine surgery.