Evaluation of cervical disc degeneration with ultralow field MRI and discography. An experimental study on cadavers.

The purpose of this study was to test the value of low-field magnetic resonance imaging (MRI) and discography in visualizing disc degeneration of the cervical spine. Plain roentgenograms, MR images, discograms, and macroanatomic appearance of the cervical spines of ten cadavers were compared. At levels C4-5-C7-T1, general disc degeneration seen in discography correlated well with macroanatomy (weighted kappa (Kw) = 0.77). The nuclear shape in MRI showed a weak correlation with macroanatomy (Kw = 0.31) and general disc degeneration in discography (Kw = 0.32), whereas nuclear intensity in MRI underestimated such changes. Magnetic resonance imaging showed posterior extension of the nucleus in most cases where moderate or severe leaking was seen in discography. The latter phenomenon represents an increase to our information on structural changes not available by any other noninvasive and nonirradiative method of examination.