Magnetic resonance imaging (MRI) of the pelvis is an imaging test that uses a machine with a powerful magnet and radio waves to create images of the organs located in the area between the pelvis bones. These structures include the bladder, prostate in men, ovaries and uterus in women, lymph nodes, large intestine, small intestine, and pelvis. Because they are obscured by bone, MRI is ideal for examining these structures.