**3. Apoptosis imaging in acute myocardial ischemia**

It has been believed that myocardium directly start to die via necrosis shortly after the onset of myocardial infarction that march of necrosis spread as a wavefront from endocardium to epicardium. However, recent animal experiments with permanent coronary artery occlusion revealed that cell death process starts as apoptosis and severe ATP depletion due to ischemia may preclude the execution of apoptosis and lead to plasma membrane permeability barrier breakdown and secondary necrosis. Therefore, apoptosis imaging might play important role in the assessment of myocardial cell death process in acute myoacrdial infarction, especially in its early stage.
