MR-myelography: a comparison with conventional myelography.

After creating a MR pulse sequence, called MR-myelography, the purpose of the study was to evaluate the value of this sequence in comparison to conventional myelography. Twenty consecutive patients were examined with conventional and MR-myelography concerning the clinical questions of chronic lumbago, spinal canal stenosis, herniated disc, spondylolisthesis and instability. Six observers assessed both examinations independently for subjective criteria such as pictorial quality, depiction of the dural sac, the nerve roots and their sheaths, artifacts, and the usefulness of single MR-myelography slices. Furthermore the number and extent of stenoses had to be judged as an objective criteria. The employed MR-myelography technique is not able to concur with the quality of conventional myelography. A high-grade stenosis is usually overestimated and low grade stenosis underestimated by MR-myelography. But it is easier to depict further relevant stenoses in a preexisting high grade stenotic spinal canal with MR-myelography. Artifacts of the introduced MR-technique do not disturb pictorial and diagnostic quality very much. In conclusion MR-myelography cannot replace conventional myelography. But together with conventional MR-sequences, MR-myelography can be helpful in the assessment of spinal canal stenosis.