What is Magnetic Resonance Imaging (MRI)

Magnetic resonance imaging (MRI) uses radio waves and magnets to make detailed pictures of the body's organs and soft tissues. These images can be seen in 3-D (3 dimensions).

How is MRI unlike Other Tests?

  • MRI does not use ionizing radiation (unlike X-rays or CT scans).
  • MRI clearly shows differences between normal and diseased tissues. The images are clearer than with CT.
  • MRI does not typically need a dye for contrast (like with CT). This is good if you have kidney problems.
  • With MRI, certain settings will show different types of tissue. This can help to more accurately make a diagnosis.

When is it Used?

MRI can be tailored to help answer almost any clinical question. It can show soft tissues in great detail. It can spot masses and cystic structures. It can clearly show blood vessels and lymph nodes.

For example, if a mass is found in the kidney, MRI can tell the difference between a hollow cystic mass and a solid mass. It can show clear 3-D images of its shape. Based on 3-D MRI images, a urologist or radiologist can see if a mass is cancerous or benign (not cancerous).