MR imaging of mouse leptomeningeal metastases.

To develop new treatment strategies for patients with leptomeningeal metastases (LM), potential therapeutic agents have to be tested in murine models first. In vivo magnetic resonance imaging has an additive value in non-invasive monitoring of the effects of therapeutic agents on LM. Previously, we described a reproducible mouse model for B16F-10 melanoma LM. In this paper, we visualize leptomeningeal melanoma metastases in mice on both T2 weighted MR images and gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA) enhanced T1 weighted MR images, using a 4.7T MR spectrometer. We conclude that both MR sequences can be used to detect and monitor LM of melanoma cells in mice. Our data further suggest that LM are more clearly visualized using T1 weighted Gd-DTPA enhanced subtraction imaging than T2 weighted imaging.