Evolving techniques for the investigation of muscle bioenergetics and oxygenation

Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) are both powerful, non-invasive methodologies and, as such, offer great potential to investigate both human biochemistry and human physiology, and ultimately to contribute significantly to the field of medicine. Consequently there has been much effort devoted to fostering the evolution of these methodologies into distinct and applicable techniques. Here we will highlight several MRI and MRS techniques for the assessment of human biochemistry and physiology that ultimately may provide useful clinical assessments and diagnoses of various muscular and cardiovascular pathologies. Specifically, the evolving techniques that will be discussed are: (1) ¹H MRS of myoglobin to assess the intracellular partial pressure of O₂, (2) ³¹P MRS to assess metabolic capacity, and (3) the combination of ³¹P chemical shift imaging to assess local metabolic demand (oxygen uptake; o₂) with arterial spin labelling to assess local perfusion (blood flow; ), in an effort to characterize the elusive spatial matching of skeletal muscle (/o₂).