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Captopril Renal Scan

Indication of a Renal Scan with Captopril 

A captopril renal scan is used to evaluate for the presence of renal artery stenosis and renovascular hypertension. This captopril scan is performed in order to rule out renal artery stenosis in patients with high blood pressure.

Captopril Renal Scan Preparation 

For all captopril renal scans it is important that you are well hydrated before the exam. You will need to drink at least one liter of fluid in the hour before your appointment. However, it is also important that you do not eat for at least four hours prior to the captopril test. Some medications needs to stopped prior to the exam, such as angiotensin II blockers and ace inhibitors.  

Renal Scan with Captopril Procedure 

Before or during the renal scan with captopril you will be given Captopril either orally or Enaloprilate intravenously. After the captopril is administered you will lie down under a gamma camera and your blood pressure and pulse will be monitored every 15 minutes for one hour.  An IV injection of a small amount of radiotracer will be given. The radiotracer will go to the kidneys dependent of function and blood flow.  During the captopril renal scan, you will be imaged with the camera under the table for approximately thirty minutes. Very rarely would you need to come back later for delay pictures which last approximately five to ten minutes.