Myocardial blood flow quantification from MRI - an image analysis perspective

First-pass perfusion imaging allows for a very high spatial resolution, noninvasive and radiation free quantification of myocardial blood flow. True quantification of perfusion images offers a unique capability to localize and measure subendocardial ischemia. Several techniques such as semiquantitative, model independent and model dependent methods are available for calculating MBF from perfusion CMR. However, for accurate perfusion quantification a few requirements need to be addressed beforehand. These include but are not limited to the relationship between the amount of injected contrast agent and the signal intensity of the MR image, used pulse sequence, and the extraction of an arterial input function. Moreover, with the new advances in CMR perfusion imaging, high spatial resolution voxel-wise quantitative analysis of myocardial perfusion is feasible. Voxel-wise quantification has the potential to combine the advantage of visual analysis with the objective and reproducible evaluation made by true quantitative methods.