Gruetter's research aims at bridging science, and biomedical applications and solutions, by working in a trans-disciplinary manner on magnetic resonance,
neurochemistry and
diabetes research. His research targets the development of fast shimming techniques and spectroscopy methods at ultra-high magnetic fields in magnetic resonance, and their application in biomedical settings, such as the non-invasive characterization of the metabolism of neural
glia cells in both rodent models and humans. Gruetter contributed to the advancement in magnetic resonance physics and engineering by showing the advantage of higher magnetic fields. His involvement in that field led among others to a fast field mapping method that has proved crucial for the demonstration of the advantage of high magnetic fields for in vivo investigation, and that has found application in several commercial scanners used to correct for susceptibility-induced B0-related distortions; to enable the simultaneous measurement of more than 20 compounds in the brain and thereby allowed for the establishment of neurochemical profiles; and to the creation of mathematical model of brain metabolism encompassing quantitative metabolic rates in the live brain. More specifically, his contributions led to the direct measurement of brain glucose levels in human brain over time; to the
in vivo measurement of
glutamine synthesis in brain and the measurement of the antioxidants; and to the
in vivo mensuration of brain
glycogen metabolism and content. Through these measurements Gruetter was able to quantify the substantial metabolic
in vivo flux of
glutamate neurotransmission; to demonstrate
in vivo via
CO2 fixation that the
anaplerotic metabolism in the brain is both important and quantitatively substantial; to prove that brain
glycogen is available in substantial amounts as a relevant emergency energy reservoir in condition of glucose-deprivation, such as
hypoglycemia, which is an important complication in
diabetes; and to establish that
astrocyte energy metabolism is substantial and that
Atp synthesis predominantly occurs by
oxidative metabolism. == Distinctions ==