Skeletal muscle can ramp up its energy turnover by orders of magnitude. Exercise recovery during ³¹P MRS is uniquely suited to study cellular mitochondrial function, glycolysis and proton kinetics in situ. We develop and combine imaging and spectroscopy techniques and dedicated RF coils to locally measure ATP, phosphocreatine (PCr) and pH directly in the exercising muscle in real time.
Blood flow and capillary perfusion deliver nutrients and oxygen to the muscle and help dispose metabolic products. Perfusion deficits or ischaemia can cause severe disorders and lead to immobilsation, infection and reduced healing. Transient ischaemia can be induced safely by pressure cuffs. Perfusion rates can change dramatically between these impaired states and maximal exercise in healthy tissue.
Arterial spin labeling (ASL) tags and traces arterial blood spins. Our developed sequences generate perfusion data every few seconds allowing time-resolved measurements without external contrast agents, simultaneously with metabolic information from spectroscopy.
We have investigated and applied measurements of intracellular muscle fat (IMCL) which are sensitive markers of insulin sensitivity, impairment of which is a precursor and feature of diabetes mellitus. Muscle glycogen is stored and used as a sugar reservoir under high work load and anaerobic metabolism. Under these hypoxic conditions, lactate accumulates and can be quantified using special spectral editing techniques.
Schmid group | Meyerspeer group