Magnetic resonance imaging (MRI) uses radio waves and a strong magnetic field to create highly detailed pictures. It can show soft tissues so specifically that it can detail blood vessels and other structures. It is so accurate, that it can show a hollow cyst from a solid mass.
Since the MRI can create three-dimensional images of a tumor's shape, it is often used for diagnosis and treatment. For kidney cancer, it can show if and where cancer has spread. On the other hand, the MRI may not helpful for the urinary tract. It cannot show abnormalities in the bladder, for example.
The MRI doesn’t use radiopaque contrast dye. MRI is unique because it does not use ionizing radiation. Instead, it uses a strong magnet, radio waves and computers to create detailed images. The patient lies down within the MRI’s huge, hollow magnet. This magnet finds the nuclei of hydrogen or water atoms in a patient’s body. Radio signals created by first "exciting" and then "relaxing" protons, create digital images, showing different types of tissue.
An MRI exam can last from two to fifteen minutes. For mostly healthy people, the MRI offers no risk. People with pacemakers, aneurysm clips, ear implants, or other metallic pieces should not get an MRI.
For more information please visit our UrologyHealth.org article on MRIs.