ABSTRACT
One of the most powerful aspects of MRI is that the observed contrast in a magnetic resonance (MR) image can be readily manipulated through the choice of experimental parameters. Selection of the type, order, strength, and duration of applied magnetic fields and RF irradiation will alter the contrast observed in the final image. The detailed pattern of RF and magnetic fields employed is called the “pulse sequence” and forms the experimental basis for every MRI scan. A large number of pulse sequences exist, and new sequences continue to be developed. Thus, versatility, in terms of pulse sequences, parameters, and image contrast, is one defining hallmark of MRI.
