A renogram is a scan that enables medical staff to look at kidney function. It is useful in highlighting conditions such as pyelonephritis, acute renal failure or rejection following transplantation.
The test takes place in the x-ray department. A mildly radioactive dye (isotope) is injected into a vein in the arm of the patient. The patient is then asked to lie down. A ‘gamma’ camera is placed close to the patient and the passage of the dye is followed ‘on camera’ through the kidneys.
The isotope should pass through the kidney within a certain length of time. Any delay may indicate abnormalities. If there is a delay, drugs may be administered intravenously during the procedure to see if they improve how the kidney works.
The whole test takes between 30 minutes and an hour.
The preparations for the test are straightforward.
The reasons for having the renogram will be discussed with you by your doctor before you are asked to sign a consent form. Very rarely, patients experience an allergic reaction to the dye or the other drugs that are injected during the test. These reactions can be treated. If you are allergic to anything, please inform your doctor.
If you are not on a fluid restriction, it is important that you have drunk plenty before the test begins.
A needle (cannula) will be placed into your arm. This is to allow the dye and other drugs to be administered during the test if necessary.
You will be asked to empty your bladder immediately before the test
The nurses will monitor you to ensure that you have suffered no adverse reactions, checking your blood pressure and pulse at regular intervals and observing you for any signs of reaction to the dye and drugs. You may have to rest on the bed for a few hours until the effects of any drugs have worn off. Although the dye is mildly radioactive, it is not generally harmful and will have disappeared entirely in 24 hours. Some of it is excreted in your urine, but only normal hygiene precautions are necessary, for example, hand washing and clearance of urine spillage.
Inpatients will be able to learn the results of their test within 24 hours. If you came for the test as an outpatient you will be told the result at your next clinic appointment. If there are abnormalities that need to be discussed before then, your doctor will contact you.