A renal perfusion scintiscan is a nuclear medicine test that uses a small amount of a radioactive substance (radioisotope) to image the kidneys and detect clinically significant narrowing of the arteries that supply them (renal artery stenosis).

Before the scan you will be asked to drink plenty of water, as it is important to be well hydrated. Shortly before the test, you will be given a medication called an ACE inhibitor, either orally or intravenously (through a vein). This is a drug used to treat high blood pressure. It is used in the renal scan to increase the likelihood of identifying a clinically significant renal artery stenosis.

Soon after the ACE inhibitor is given, you are asked to lie on the scanner table and a small amount of radioisotope is injected into a vein. The kidneys are then scanned for approximately 30 minutes. The images are taken as the radioactive material flows through the renal arteries and into the kidneys. It is very important to remain still throughout the examination.

Approximately 10 minutes after the radioisotope is injected, a diuretic, usually furosemide, is given intravenously. Like the ACE inhibitor, the diuretic increases the accuracy of the test.

After the scan, no recovery time is required. You will be asked to drink plenty of fluids to help excrete the radioactive material from your body.

There is no need for fasting or special diet. You will be asked to drink plenty of water before the scan.

If you are currently taking an ACE inhibitor for high blood pressure, you may be asked to discontinue your medication before the examination. Always consult with your health care provider before discontinuing any medication.

You may be asked to wear a hospital gown. Remove all jewelry and metallic objects before the scan.

Infants and children:

The preparation you can provide for this test depends on your child's age, previous experiences, and level of trust. For general information regarding how you can prepare your child, see the following topics:

• Infant test or procedure preparation (birth to 1 year)
• Toddler test or procedure preparation (1 to 3 years)
• Preschooler test or procedure preparation (3 to 6 years)
• School age test or procedure preparation (6 to 12 years)
• Adolescent test or procedure preparation (12 to 18 years)

You may feel a small amount of pain when the needle is inserted.

You must remain still during the scan, and you will be instructed when to change positions by the technologist.

There may be some discomfort as your bladder fills with urine during the examination. Inform the technologist if you must urinate before the completion of the scan.

The test evaluates blood flow to the kidneys, in the setting of suspected renal artery stenosis. Clinically significant renal artery stenosis may be a cause of high blood pressure (hypertension) and kidney problems.