Ultrasound (also called ultrasonography, or a sonogram) uses high-frequency sound waves to create real-time images. It's a simple, flexible and painless way for urologists to look at many organs without using dyes or radiation. These exams help check what is causing you pain, swelling or an infection. An ultrasound is painless, safe and often risk-free. Urologists use ultrasound to look at the kidneys, bladder and testicles.
Magnetic resonance imaging (MRI) is also a painless imaging test that uses radio waves and a strong magnetic field to create highly detailed pictures. Since the MRI can create three-dimensional (3-D) images of say, a tumor's shape, it is often used for diagnosis and treatment.
An MRI can help doctors find cancer in the body and show if and where the cancer has spread. MRI is being used more for prostate biopsies that help urologists look for cancer. People with pacemakers or other metallic pieces should not get an MRI. Sometimes intravenous contrast ("dye") is injected to help define structures.
The CT scan is used by doctors to see and test cross-sectional slices of tissue and organs. It combines X-rays and computer calculations for detailed images. These scans can accurately gather real-time images in seconds, with no gaps. It can show solid vs. liquid structures, when intravenous radiopaque contrast ("dye") is injected. Specialized CT scans can make 3-D images of the kidney and blood supply.
These can show problems with blood flow and offer a "road map" for planning surgeries. CT scans are generally safe, efficient, and effective, with minor risks. Some patients can have an allergic reaction to the radiopaque dye. It is one of the best tools for finding problems in the urinary tract, including stones and masses.
Dr. Ajay K. Nangia is Professor of Urology and Clinical Director of Andrology at the University of Kansas Medical Center. He is a member of the Urology Care Foundation's Public Education Council.