MRI features of medulloblastoma with extensive nodularity: (a)–(c) axial sequences reveal a posterior fossa mass (arrows) with decreased diffusivity on DWI (a) and ADC sequences (b), without specific intratumoral abnormalities on SWI sequence aside from amorphous susceptibility artifact present along the vermis from prior surgical biopsy (c). Sagittal sequences reveal extensive nodularity on T2 (d) and postgadolinium (f) sequences that is less evidence on precontrast T1-weighted sequences where the nodular areas appear more hypointense (e).