Wavelet-analysis of DCE-MR images was performed to explore the association between radiomics information and relaxivity-change (ΔR1) in human U251n tumors grown in rat brains. Sixteen DCE-MRI experiments (8 rats before- and after- radiation) were studied. Wavelet-decomposition analysis was performed using ΔR1 time trace. Frequency-based localized approximations of ΔR1 with four degrees of regularities were estimated and compared to the volume-transfer-constant (Ktrans, calculated from a modified Tofts-model pharmacokinetic analysis). Results confirm strong associations between wavelet-based radiomic information and contrast uptake/flow/leakage in the tumor vasculature. Results suggest that radiomics has potential as a biomarker of tumor physiology.