A kidney ultrasound is a diagnostic procedure that uses high-frequency sound waves to create images of your kidneys as well as blood flowing through the vessels of the kidneys. The sound waves bounce off structures within the organ travelling at different speeds through different tissues. This information is processed by a computer to form images, which may be viewed on a monitor.
Kidney ultrasounds may be performed to evaluate the size, shape and location of the kidneys and related structures (ureters and bladder) and identify obstructions, tumours, cysts, stones, abscesses and areas of infection. It may also be helpful in guiding your doctor while placing a drainage tube (for draining a cyst or abscess) or needle (for obtaining tissue samples). It may also be used to assess a transplanted kidney.
Depending on the suspected problem, you will be instructed accordingly before the procedure. If your bladder is being evaluated, you will need to have a full bladder and you will be able to void following the procedure. You will lie down on your stomach for the test. A gel is applied over the region of your kidneys to provide lubrication and help conduct the sound waves. A device called a transducer, which produces and receives sound waves, is glided over the gel. The images are created and stored for your doctor to review. Ultrasounds are harmless, and the procedure is usually not associated with any risks.