Restricted Magnetic Resonance Diffusion-Weighted Imaging With Mass Lesions Presenting as Acute Lesions

Diffusion-weighted imaging is useful for diagnosis of acute ischemic stroke. However, metastatic brain lesions may also demonstrate restricted diffusion on magnetic resonance imaging. We describe 4 cases (3 with metastatic neoplasms and 1 with a meningioma) with positive findings by diffusion-weighted imaging.