Background tissue signals such as water and/or fat are suppressed in an MR
image by using an imaging agent that chemically shifts the tissue spins
of interest. An imaging pulse sequence is used to acquire the image data
using an RF excitation pulse that is tuned to the off-resonance tissue
spins of interest with the saturation pulse sequences being interleaved
with the imaging pulse sequences to selectively suppress signals from
on-resonance background tissues such as water and/or fat.