The value of MR imaging in differentiating between hard and soft cervical disc disease: a comparison with intraoperative findings

The aim of this study is to assess the accuracy of MRI alone in the differe ntiation of soft cervical disc protrusion from osteophytic compression in c ervical disc disease. In a retrospective study, the MRI scans of 41 patient s with cervical disc disease, who had previously undergone surgery, were pr esented to three independent observers, randomly on two different occasions , to identify the accuracy of the diagnosis of the presence of hard or soft disc or both as a cause of compression. The observers (two neurosurgeons a nd one neuroradiologist) were not involved with the treatment of the cases at any stage and were unaware of the surgical findings. Their observations were compared with those of the surgeon recorded at operation. The intra-ob server agreement was poor for diagnosis into three categories as hard or so ft disc or both. In distinguishing between the presence or absence of hard disc, there was moderate to good (Kappa = 0.6) intra observer and fair to m oderate (Kappa = 0.3) interobserver agreement. The sensitivity of diagnosis of a hard disc was high (87%) but specificity was low (44%), due to the ov erestimation of the presence of hard disc. There was a significantly higher incidence of hard disc in the elderly age group (76% over the fifth decade , P = 0.0073). It is concluded that MRI alone is not a very efficient diagn ostic tool in distinguishing between hard and soft disc in the cervical dis c disease.