Thoracic Outlet
Your doctor suspects you may have thoracic outlet syndrome, which results in pinching off the artery to your arm when you move in a certain way. This procedure will determine a change in the circulation to your arm when it is moved into certain positions.
Ultrasound technology is safe and images arteries and veins. There is no radiation or injection of chemicals. This procedure is performed to evaluate the popliteal artery for possible aneurysm or blockage.
At the Cedars-Sinai S. Mark Taper Foundation Imaging Center, we have a specialized team of physicians and technologists who are experts in ultrasound technology.
Before Your Exam
- There is no preparation for this exam and you may eat and drink. You may take your scheduled medications.
- If your doctor gave you an order, please bring it with you.
- Bring a magazine, book or music player to help you pass the time in case you have to wait.
- Leave valuables and jewelry at home. Please do not eat or drink six hours before your exam. You may take any scheduled medication with a sip of water.
During Your Exam

Graphs from a thoracic outlet vascular ultrasound study showing blood flow in the arms.
- You will be sitting on the exam table on your back with your hands at your sides. The technologist will apply a warm gel to your arms and a transducer or a small microphone will be used to examine your arteries.
- You will hear the sound of moving blood during the exam. Do not be alarmed; it is harmless. The exam will take approximately 60 minutes.
After Your Exam
Your study will be read by a physician who will send the results to your doctor. Your doctor, who ordered the study, will explain the findings to you. If you have problems related to your procedure, please call 310-423-8000. To request a copy of your report, please call 310-423-8000, option 2 or submit an online request.