Quantification of Regional Myocardial Perfusion by Exponential Infusion of 11C-Butanol

This study was designed to determine whether regional myocardial perfusion can be assessed quantitatively in vivo in dogs by administration of a freely diffusible tracer intravenously at an exponentially increasing-rate. Previously, we reported the mathematical basis of the approach and its use for assessment of global perfusion in isolated hearts. In this study, computer simulations demonstrated that inter-regional diffusion of tracer perturbs results by no more than 7 percent under worst case conditions. Regional myocardial blood flow assessed in open chest dogs with myocardial activity deternined by well counting by the exponential infusion method correlated closely to values obtained with radiolabeled microspheres (r = 0.986, n = 35 determinations). Thus, regional myocardial perfusion can be quantified with an infusion technique potentially applicable to the tomographic characterization of impaired perfusion in experimental animals and ultimately in patients with positron emission tomography.