MR pulse sequence software is typically developed in small incremental steps. For example, an investigator may receive a new state of the art sequence from the manufacturer of the scanner equipment. (S)he may then decide to add flow-sensitizing gradients. This process is not straightforward, but requires extensive testing, first in phantoms and then in-vivo, to determine if the pulse sequence is capable of performing the new task and, moreover, to see if the new feature does not introduce undesired artifacts.