NIMG-53. DELTA RELAXOMETRY WITH CONTRAST ENHANCED MAGNETIC RESONANCE FINGERPRINTING: INITIAL APPLICATION TO DIFFERENTIATE BRAIN METASTASES AND GLIOBLASTOMA

Abstract PURPOSE The utility of post-contrast magnetic resonance fingerprinting (MRF) for brain tumor assessment has not been assessed. aim this work is to report differences in MRF-derived delta-relaxometry metrics between metastases and glioblastoma, offering a new strategy differentiation. METHODS Post- pre-contrast MRF (T1, T2 proton density maps) were acquired from 29 patients (14 (Met), 15 glioblastoma (GB)) along with conventional MRI (T1w, T1w-Gd, T2w, T2w-FLAIR, ADC). Post-contrast was skull-stripped non-linearly co-registered MRF. Delta relaxometry (ΔR1/ΔR2 ratio, ΔR1, ΔR2, normalized ΔR1/ΔR2) calculated the native image space (1.2x1.2x3.0 mm3). Tumor regions segmented using DeepMedic into necrotic core (NC), enhancing (ET), peritumoral edema (ED). ROI-averaged means delta compared paired t-test ET ED Met vs GB. Voxel-wise ΔR1/ΔR2 ratios (log transformed) unpaired two-tailed Bonferroni correction quantify distribution RESULTS Across all voxels each group, GB different (0.272±0.61 0.247±0.66 ED, p < .001; 0.278±0.69 0.264±0.67 ET, .001). On per-patient basis, median, 75th percentile, 90th percentile (p Within-ROI (NC, ED) averaged mean ΔR1/R2 significantly CONCLUSION types (Met GB) both regions. regions, but specific type. provides unique tumor-specific contrast shows potential solid as well differentiation