Doppler Allen's Test Ultrasound

Ultrasound is a procedure that uses sound waves to "see" inside your body. A Doppler Allen's test uses sound waves to create a "map" of the arteries in your hand to prepare for various procedures, including bypass graft surgery (bypassing diseased vessels in your body with the healthy arteries from your forearms).

At the S. Mark Taper Foundation Imaging Center, we have a specialized team of physicians, nurses, and technologists who are experts in ultrasound imaging.

Before Your Exam

Image from a Doppler Allen's Test showing blood flow in the arteries in the hand. The chart shows blood flow as a wave pattern.

  • There is no preparation for this procedure.
  • If your doctor gave you an order, please bring it with you.
  • We want to make your waiting time as pleasant as possible. Please consider bringing your favorite magazine, book or music player to help you pass the time.
  • Please leave your jewelry and valuables at home.
  • Directions and parking information

During Your Exam

  • The vascular technologist will explain your exam and answer any questions you may have.
  • Your procedure will be performed with you either lying on the examination table on your back or sitting at the bedside with your hands at your sides or on your stomach.
  • The technologist will apply warm gel to your forearms.
  • A transducer, a small device similar to a microphone, will be placed over various locations on your forearms and fingers.
  • You will not feel any pain; however you will feel mild pressure from the transducer.
  • The sound waves bounce off the blood moving in the arteries in your arms. This creates "echoes," which are converted to images on a television monitor.
  • You will hear unusual sounds as the technologist listens and records the blood flowing through the arteries in your forearms.
  • Additionally, tracings (photoplethysmography, also known as PPG) tracking blood to your fingertips will be taken.
  • Your exam will take approximately 20 minutes. 

After Your Exam

  • There are no post-exam instructions.
  • Your study will be reviewed by a vascular surgeon and the results sent to your physician. Your physician will discuss these results with you and explain what they mean in relation to your health.
  • If you have any problems related to your procedure, please call 310-423-8000.
For more information or to schedule an appointment