Figure 1: This dural-based metastasis along the inferior aspect of the frontal lobe is causing a tremendous amount of hyperintense edema on this sagittal FLAIR image (top row left). Coronal (top row right) and sagittal (middle row left) post-contrast T1 images show this lesion to have bright enhancement and a broad dural base, a finding more typically seen with meningioma, a common mimic of metastatic disease. Diffusion weighted image (middle row right) and ADC (bottom row) show bright and dark appearances, typical of lesions with dense cellularity as is the case with many types of metastases.
Figure 2: The difference between sagittal T1 pre-contrast (top row left) and post-contrast (top row right) images is striking in this patient with leptomeningeal metastatic disease, with diffuse enhancement throughout the cerebral sulci that is also visible on coronal (middle row left) and axial (middle row right) contrast-enhanced images. Scattered hyperintense sulci are also visible on FLAIR imaging (bottom row), along with reactive or metastatic thickening of the dura. Leptomeningeal metastatic disease is often very nodular, but can sometimes be smooth, as in this patient.
Figure 3: A single large hemorrhagic lesion can often be a diagnostic conundrum with a large differential. This melanoma metastasis demonstrated evidence of extensive hemorrhage, with areas of T1 hyperintensity (top row left), Low T2 signal intensity and T2-hyperintense surrounding edema (top row righ...