[Vertebral body metastases: characteristic MRI findings in epidural infiltration]

In case of lumbar vertebral metastasis associated with anterior epidural carcinomatous infiltration, we have observed that infiltrations tend to respect the midline. This study led to the systematic recognition of these phenomena in vertebral metastases.

11 patients with 17 vertebral metastases and adjacent anterior epidural infiltration were reviewed retrospectively. All cases were studied by MRI. The routinely used imaging technique included spin echo (SE) T1 and T2 weighted sequences in the sagittal plane native and T1-SE without and with Gd-DTPA in the axial planes. The radiological findings of these phenomena and the anatomy were studied.

We observed these phenomena to be uni- or bilateral in 88.3% of all cases with intraspinal anterior epidural carcinomatous infiltration, especially in that part of the vertebral body where the basal vertebral venous plexus was located.

We conclude that vertebral metastases respect the midline. We interpret this fact as being due the anatomy of the vertebral body and especially its stabilization by the posterior longitudinal ligament. These findings may be helpful in the differential diagnosis of vertebral body metastases with epidural infiltration in contrast to intraspinal processes which proceed with the destruction of the vertebral body.