How to Shorten MRI Sequences

MRI offers an unrivaled method for detailed anatomical imaging with a high degree of flexibility in the image contrasts which may be generated. However, this flexibility comes at the cost of considerable complexity in the determination of the optimum sequence for any given application. It is rare, however, that an imaging task is created from scratch; often an MR sequence needs to be modified in response to a clinical challenge. For fetal imaging, this is most often to compensate for motion in utero. This chapter seeks to present to the non-MRI specialist the consequences and trade-­offs encountered when modifying scan procedures, to provide a background and common ground for the development of fetal imaging protocols.