Cell Density and Spacing Influence DSC-MRI Data Acquired in Brain Tumors

Natenael B. Semmineh¹, Junzhong Xu², Jerry Boxerman³, C Chad Quarles²

Brain tumor DSC-MRI studies can be confounded by extravascular T2* effects that occur when the contrast agent extravasates. The resulting signals are consequently influenced by the extravascular compartmentalization of the contrast agent and therefore may depend on the spatial distribution of tumor cells within tissue. Using simulations we demonstrate that ∆R2* is non-linearly related to cell density, with the greatest influence occurring at cell volume fractions between 40 60%. We also show that the spacing of cells within a voxel can alter ∆R2* values by as much as 50% for spacing variations on the order of the cell size.