In 7 year old posterior fossa mass with cyst formation, hypodense on CT, hyper intense on T2WI and showing post gadolinium nodule enhancement is

C i.e. Astrocytoma Posterior Fossa tumors in children Features Astrocytoma Ependymoma Medulloblastoma Cyst Formation Very cominonQ Common Rare CT scan IlypodenseQ Rare Isodense No Hyperdense Yes (15-40%) CSF seeding Transforaminal spread No Yes No Calcification -10% 40-50% 10-15% T2WI Hyper (intense) Hyper/Iso Iso T1 WI Iso/Hypo Iso/Hypo Iso/Hypo Postgadolinium (contrast) Nodule enhanceQ Mild Moderate