Decreased tissue stiffness in glioblastoma by MR elastography is associated with increased cerebral blood flow

•Stiffness and viscosity were lower in glioblastomas than in healthy tissue.•Tumor stiffness was heterogeneous both within each tumor and between patients.•Abnormal tissue properties were present in regions of normal-appearing tissue.•Including MR elastography measures in statistical models helped predict perfusion.•Stiffer tissue was associated with lower perfusion values. Understanding how mechanical properties relate to functional changes in glioblastomas may help explain different treatment response between patients. The aim of this study was to map differences in biomechanical and functional properties between tumor and healthy tissue, to assess any relationship between them and to study their spatial distribution. Ten patients with glioblastoma and 17 healthy subjects were scanned using MR Elastography, perfusion and diffusion MRI. Stiffness and viscosity measurements G′ and G′′, cerebral blood flow (CBF), apparent diffusion coefficient (ADC) and fractional anisotropy (FA) were measured in patients’ contrast-enhancing tumor, necrosis, edema, and gray and white matter, and in gray and white matter for healthy subjects. A regression analysis was used to predict CBF as a function of ADC, FA, G′ and G′′. Median G′ and G′′ in contrast-enhancing tumor were 13% and 37% lower than in normal-appearing white matter (P