Fig. 1

Schematic illustration of the vascular reduction as function of the voxel size. As the voxel size is reduced, the vascularity of the regional vessel network within the voxel becomes less complex; thus, using a single effective vessel with multi vascular attributes to calculate the local pO₂ becomes possible. In the MPO2 model, a single straight cylindrical vessel is placed at the center of the voxel and the average voxel pO₂ (MPO2) is calculated. The effective vascular structure and its functional inputs (e.g. blood flow, hemoglobin concentration, and fraction of vessel volume) are obtained from in vivo imaging measurements, thus providing a means to fuse this information based on the biophysics model approach