Myocardial perfusion studies with short-TR MR imaging

The non-invasive diagnosis and assessment of myocardial infarction and ischemic heart disease with MR imaging await a technique sensitive to tissue perfusion. A short repetition time pulse sequence (GRASS) using small flip angles of 200-400, in conjunction with gradient echoes, was recently developed. Gradient reversal assures a signal even though the spins may have partially or fully exited the section. Electrocardiographically gated acquisition provides 32 images per cycle. Signal intensity plots from regions of interest in the normal myocardium provide a cyclical curve corresponding to the unique profile of coronary flow curves. Further, signal intensity is observed to spread from the epicardium to the endocardium