Diagnostic imaging algorithm for cervical soft disc herniation.

MR imaging with surface coils is currently the preferred method for the evaluation of cervical soft disc herniation. However, the differentiation between soft disc herniation and osteophytic spurs in the neural foraminal canal is not always obvious on a 0.5 Tesla unit. Therefore the specificity for neural foraminal canal pathology has been reported not to be very high. We evaluated MRI in selected patients without major foraminal spurs or important spondylosis on plain radiography. This prospective study includes 100 patients with cervical radicular symptoms, not subsiding after conservative treatment. All patients underwent plain radiograms. Patients without spinal instability, spondylosis or major osteophytes on plain radiograms and without clinical findings of myelopathy underwent MRI (n = 59) on a 0.5 Tesla superconducting system. All 41 other patients underwent CT myelography. On MRI, a cervical soft disc herniation was observed in 55 out of 59 investigated patients and the localization corresponded well with the clinical symptoms. CT myelography demonstrated a foraminal herniation in 1 of 4 selected patients with negative MRI. Fifty out of 55 patients underwent anterior cervical discectomy without fusion. All herniations were confirmed at operation, but in two patients there were important foraminal spurs, not seen on MRI. The specificity of MRI in this study is 94%. It is concluded that 0.5 T MRI, combined with plain films offers an accurate, noninvasive test in the assessment of selected patients with cervical radiculopathy.