Figure 14.

Hyperdense brain parenchymal metastatic disease. 55-year old man with history of lung cancer presents for CT imaging with acute left sided weakness. Non-contrast CT (left) demonstrates a left temporal hyperdense mass with surrounding white matter hypodensity. Subsequent contrast enhanced MR imaging (right) demonstrated a enhancing mass with surrounding vasogenic edema consistent with metastatic disease. A majority of intraparenchymal metastatic lesions will appear iso- to hypodense on non-contrast CT imaging. Lesions with a high nuclear to cytoplasmic ratio often appear hyperdense on non-contrast CT despite the lack of underlying hemorrhage