Synopsis

Keywords: Physics & Engineering: Physics, Physics & Engineering: RF Safety

Imaging with MR begins with one or more radiofrequency (RF) pulses, making them a key component of any MRI pulse sequence. This lecture will review the fundamentals of RF pulses in MRI, including hard pulses vs. soft pulses, sinc pulses, slice/magnetization profiles, the small-tip angle approximation, RF bandwidth and the time-bandwidth product. Similarities and differences among excitation, inversion and refocusing pulses will be emphasized. The lecture will conclude with a discussion of advanced topics such as the Shinnar-Le Roux (SLR) algorithm for RF pulse design and adiabatic pulses, highlighting the need for these types of pulses and their applications.