Meningeal carcinomatosis in the VX2 rabbit tumor model: detection with Gd-DTPA-enhanced MR imaging.

Meningeal carcinomatosis developed in 14 of 14 New Zealand White rabbits after infusion of a VX2 tumor cell suspension into the cisterna magna. All died or were killed 7-15 days after inoculation. Within days of the tumor infusion, magnetic resonance (MR) imaging with gadolinium-diethylenetriaminepentaacetic acid (DTPA) at 0.5 or 1.5 T demonstrated enhancement of the cerebrospinal fluid (CSF) secondary to disruption of the blood-CSF barrier by plaquelike lesions along the meninges. Eventually, meningeal enhancement was observed along the base of the brain and cervical spine. Quantitative assessment of the contrast enhancement on T1-weighted images revealed an increase in mean signal intensity of 213% +/- 130%. Contrast enhancement was not observed in four control animals who received an infusion of cell culture medium. These results demonstrate in an animal model that contrast material-enhanced MR imaging can be used to detect meningeal carcinomatosis by revealing breakdown of the blood-CSF barrier.