Figure 3. A 59-year old male presented with positional nausea found to have a 0.7 cm transverse × 0.9 cm anteroposterior × 1.3 cm craniocaudal, homogeneously-enhancing mass in the floor of the fourth ventricle. Patient was treated with suboccipital craniotomy and C1 laminectomy. (A) Lesion is isointense to gray matter on a sagittal T1-weighted image before gadolinium contrast administration. (B) Superior portion of lesion enhances homogeneously on a sagittal T1-weighted image post-contrast.