MR Myelography in Patients with Lumbosacral Radicular Pain: Diagnostic Value and Technique

Lumbosacral radicular sciatic pain can frequently be the result of nerve root compression, for instance by a herniated lumbar disc. Spinal imaging may however reveal disc herniations which are not associated with sciatica, even present in individuals without any complaints. In addition, sciatic pain may be the result of spinal or even paraspinal pathology without any involvement of the nerve root: so-called "pseudo" radicular pain. It is important therefore in clinical diagnostic imaging to match the potential cause of sciatica (e.g. a disc herniation) as closely as possible with its effect (actual compression of the nerve root). Assessing nerve root compression is not always easy on standard MR images. MR myelography provides a high-resolution image of the normal or compressed nerve root in a very brief acquisition time which enables the MRM acquisition to be added on to the standard examination. The MRM images provide valuable supplementary information but cannot replace the standard T1- and T2-weighted sagittal and axial images.