The principal focus of this article has been to discuss the issues relating to the quantitation of myocardial perfusion using MCE. In its current form, this technique can provide important physiological information in the cardiac catheterization laboratory and the operating room as well as in the experimental laboratory. Standardization of echo contrast agents, echo equipment, and algorithms for image analysis will make it a truly quantitative technique in the near future. MCE has the potential to offer the unique opportunity of simultaneously assessing regional myocardial flow and function in various ischemic syndromes.