A renogram involves the intravenous injection of a small amount of radioactive tracer so that images can record blood flow in and out of the kidneys as well as flow of urine through the kidneys, ureters and bladder.

In some cases of hypertension (high blood pressure) a Captopril renogram can be requested.

Why is it performed?

A renogram is performed in order to determine kidney function. The scans can pick up obstructions as well as a number of other issues, including high blood pressure (in certain cases where there is stenosis/narrowing of the renal arteries). The scan may also be performed in cases where a kidney transplant was performed and your doctor may need to evaluate its success. If a kidney transplant has been rejected, you may need to undergo a nuclear renal scan so that your doctor can assess blood flow and the possibility of rejection

How does it work?

During the scan, a radioactive tracer is injected intravenously into the body. The tracer reaches the kidneys via the bloodstream and a special gamma camera takes images every 30 – 60 seconds (dynamic phase), which help your doctor to properly assess the function of the kidneys, and come up with a suitable treatment plan. During the scan it is important to keep still, so that images are clear and accurate. The scan is typically an outpatient procedure, and usually takes about 45 minutes.

In young children where sedation is required (or in babies), these scans are normally performed as in-patients.