Axial T2 and coronal T1W (IR) images of the posterior fossa show a very large heterogeneous
mass in the fourth ventricle. The mass extends through the left foramen of Luschka into the CP
angle, causing compression and marked displacement of the brainstem to the right.
Coronal T1W image (upper left) confirms the 4th ventricular mass. Axial, coronal and
sagittal post contrast T1 weighted images demonstrate a heterogeneous, enhancing
mass in the fourth ventricle. The lateral and third ventricles are markedly enlarged
indicating obstructive hydrocephalus.
Key words: mri tumor neoplasia
Primitive Neuro-Ectodermal Tumor (PNET)