Use of Oxygen Challenge to Assess Myocardial Oxygenation: A Potential Tool to Image Oxygen Metabolism.

Marzena M. Wylezinska¹, Jordi L. Tremoleda¹, Joseph Habib², Daniel Stuckey², Willy Gsell¹

Aerobic metabolism is a vital and fundamental mechanism of attaining energy in mammals. Due to the diversity of organic substrates involved, the rate of aerobic metabolism can only be directly measured through the oxygen consumption. However, current non-invasive quantitative techniques (15O-PET, 17O-MRI) have been limited by both their expense and complexity. We propose a novel technique in which BOLD-dependent changes in T2* were measured in conjunction with saturating arterial blood with oxygen to extract the effects of the reduction of oxy-haemoglobin. Myocardial T2* was observed to increase by 15% thus offering a robust quantitative index of aerobic metabolism.