Changes in Cellular and Vascular Phenotype in Pediatric Ependymoma Models by Multi-Parametric MRI: Effects of Tumor Size and Radiation Treatment

At 2022 ISMRM, we presented on simulation results of the selective size imaging using filters via diffusion times (SSIFT) in perfused irradiated cells and flank xenograft models. Here, using SSIFT and iron-oxide vessel-size imaging, we report on ependymoma (EPN) phenotypes, comparing small and large intracranial lesions: variable cell sizes fitted into SSIFT iAUC (S=14 microns small EPN, S=19 medium and S=12 large), increased vessel density index (Q=0.54 small, Q=0.62 large EPN), and low ADC (0.63x10-3 small, 0.58x10-3 mm2/s large EPN). Chemo-radiation treatment led to decreased gross tumor volumes, necrosis with decreased cell sizes and increased ADCs.