Oxygenation-sensitive CMR for assessing vasodilator-induced changes of myocardial oxygenation

Background. as myocardial oxygenation may serve as a marker for ischemia and microvascular dysfunction,it could be clinically useful to have a non-invasive measure of changes in myocardial oxygenation. however,the impact of induced blood flow changes on oxygenation is not well understood. we used oxygenation-sensitive cmr to assess the relations between myocardial oxygenation and coronary sinus blood oxygen saturation (svo2) and coronary blood flow in a dog model in which hyperemia was induced by intracoronary administration of vasodilators. results. during administration of acetylcholine and adenosine,cmr signal intensity correlated linearly with simultaneously measured svo2(r 2 = 0.74,p < 0.001). both svo 2and cmr signal intensity were exponentially related to coronary blood flow,with svo2 approaching 87%. conclusions. myocardial oxygenation as assessed with oxygenation-sensitive cmr imaging is linearly related to svo 2and is exponentially related to vasodilator-induced increases of blood flow. oxygenation-sensitive cmr may be useful to assess ischemia and microvascular function in patients. its clinical utility should be evaluated. © 2010 vöhringer et al; licensee biomed central ltd.