Fig. 1

Clinical observations (data) versus simulations results for (1) pure diffusion (2) Enhanced diffusion (\(\alpha \)) and local clearance (r) and (3) Diffusion and bulk flow (\(\phi \)). Concentrations are shown as regional averages over all patients at 24 and 48 h after tracer injection. All methods provide reasonable alignment with the data after 24 h. However, 48 h after injection, pure diffusion overestimates tracer amount found within the brain. Models using enhanced diffusion with local clearance and diffusion with bulk flow give reasonably good agreement with data both after 24 and 48 h. Sustained concentrations in the white matter as observed in data, is not seen when local clearance is included in the model