A new kinetic model for characterization of glucose delivery, transport and metabolism for MRS and dynamic glucose enhanced (DGE) MRI of the brain

Motivation: While PET, MR spectroscopy, and DGE CEST MRI can describe sugar uptake and utilization using a 2-tissue-compartment model, such a model is not appropriate for DGE CEST MRI of tumors, as the exchange properties of sugar hydroxyl protons may differ between tissue compartments. Goal(s): To develop a 3-tissue-compartment model (blood, EES and cell) suitable for DGE MRI. Approach: We modified the mass balance equations and simulated compartmental D-glucose concentrations from D-glucose levels of venous plasma. Results: The 3-tissue-compartment model was able to reproduce MRS literature brain D-glucose dynamic uptake curves, as well as experimental DGE MRI signal in brain tumors at 7 T. Impact: A 3-tissue-compartment model is necessary for correct quantification of DGE MRI in malignant brain tumors. Our proposed model is expected to improve modeling and assessment for all metabolic substrate uptake imaging methods in situations of BBB breakdown.