What Is a Thoracic Outlet Ultrasound?
A thoracic outlet evaluation is a specialized vascular ultrasound examination that assesses blood flow through the subclavian artery as it passes through the thoracic outlet—the narrow space between the collarbone (clavicle), first rib, and surrounding muscles. This examination uses Doppler ultrasound to evaluate whether blood flow becomes restricted when the arm or shoulder is placed in specific positions.
​
Thoracic outlet evaluation is commonly performed when Thoracic Outlet Syndrome (TOS) is suspected. During the examination, blood flow is measured both at rest and while your arms are moved through a series of positioning maneuvers designed to determine whether the artery becomes compressed.
​
Unlike X-rays, CT scans, or angiography, thoracic outlet ultrasound does not use radiation or contrast dye. It provides real-time assessment of blood flow during movement, making it an effective, non-invasive way to evaluate vascular compression.
Why Is a Thoracic Outlet Syndrome (TOS) Vascular Evaluation Performed?
A Thoracic Outlet Syndrome (TOS) Vascular Evaluation is performed to assess blood flow through the arteries and veins as they pass from the neck into the shoulder and arm. This examination uses Doppler ultrasound to evaluate how blood flow changes during different arm positions that may compress the blood vessels. It is a safe, noninvasive, and radiation-free examination that does not require contrast dye.
​
This examination is commonly performed when vascular Thoracic Outlet Syndrome (TOS) is suspected. TOS occurs when the blood vessels or nerves passing through the thoracic outlet—the narrow space between the collarbone and first rib—become compressed. During the examination, your arms are placed in several positions to determine whether blood flow changes with movement.
​
A Thoracic Outlet Syndrome Vascular Evaluation may be recommended if you experience arm pain, numbness, tingling, weakness, swelling, coldness, color changes, fatigue with overhead activities, or other symptoms that worsen when your arms are raised or used repeatedly. The examination can identify arterial compression, venous compression, or other vascular abnormalities that may contribute to your symptoms.
​
This study may also be performed to evaluate abnormal findings from a physical examination or another imaging study, monitor known vascular Thoracic Outlet Syndrome, or assess the results of treatment or surgery.
​
As a safe, painless, and radiation-free examination, a Thoracic Outlet Syndrome (TOS) Vascular Evaluation provides valuable real-time information about blood flow during arm movement, helping diagnose vascular compression and guide appropriate treatment and follow-up care.
Common Reasons to Schedule a Thoracic Outlet Syndrome (TOS) Vascular Evaluation
A Thoracic Outlet Syndrome (TOS) Vascular Evaluation is performed to assess blood flow through the arteries and veins of the neck, shoulder, and arm during different arm positions. You may benefit from this examination if you have symptoms or medical conditions that suggest vascular compression at the thoracic outlet.
​
-
Suspected Thoracic Outlet Syndrome (TOS)
-
Arm pain that worsens with overhead activities
-
Numbness or tingling in the arm or hand
-
Weakness or fatigue of the arm during use
-
Swelling of the arm or hand
-
Coldness of the arm or hand
-
Color changes of the arm or fingers (pale, blue, or purple)
-
Heaviness or aching in the arm with repetitive movements
-
Symptoms that occur when raising or extending the arms
-
Suspected arterial or venous compression at the thoracic outlet
-
Evaluation of abnormal pulses during arm positioning
-
Follow-up of previously diagnosed vascular Thoracic Outlet Syndrome
-
Monitoring after treatment or surgery for Thoracic Outlet Syndrome
-
Evaluation of abnormal findings from a physical examination or another imaging study
Â
A Thoracic Outlet Syndrome (TOS) Vascular Evaluation uses real-time Doppler ultrasound to evaluate blood flow during a series of arm positions and maneuvers. It is a safe, painless, and radiation-free examination that helps identify arterial or venous compression, guiding appropriate diagnosis, treatment, and follow-up care.
What to Expect During Your Examination
A thoracic outlet evaluation is a safe, non-invasive vascular ultrasound examination that typically takes 45–60 minutes to complete. During the study, a registered vascular sonographer evaluates blood flow through your subclavian arteries while your arms are placed in several different positions. These positioning maneuvers help determine whether blood flow becomes reduced or temporarily compressed as the thoracic outlet changes during movement.
​
You will lie comfortably on an examination table while a small amount of warm ultrasound gel is applied near your collarbone and shoulder (subclavian region). A handheld ultrasound transducer is placed over the area to obtain Doppler images and blood flow measurements.
​
Throughout the examination, you will be asked to perform a series of arm and shoulder maneuvers, such as raising your arms, turning your head, or changing your arm position. These movements are an important part of the examination because they allow the sonographer to evaluate blood flow both at rest and during positions that may reproduce your symptoms.
​
The examination is painless and does not involve needles, injections, radiation, or contrast dye. Once the study is complete, the ultrasound gel will be removed, and you may immediately return to your normal daily activities.
How to Prepare for Your Thoracic Outlet Syndrome (TOS) Vascular Evaluation
A Thoracic Outlet Syndrome (TOS) Vascular Evaluation requires very little preparation. Following these simple instructions will help ensure your examination is completed comfortably and accurately.
​
Before Your Appointment
​
✓ No fasting is required. You may eat and drink normally before your examination.
✓ Continue taking your prescribed medications unless instructed otherwise by your healthcare provider.
✓ Wear loose-fitting clothing, preferably a short-sleeved or sleeveless shirt, to allow easy access to your neck, shoulders, and arms. You may be asked to change into an examination gown.
✓ Avoid wearing bulky jewelry or accessories around your neck, shoulders, or arms, as they may interfere with the examination.
✓ Bring any previous ultrasound, CT angiography (CTA), MR angiography (MRA), venography, or other imaging studies related to your neck, shoulder, or arm circulation if they were performed at another facility.
✓ Arrive 10–15 minutes early to complete any necessary paperwork before your examination.
​
During the examination, you will be asked to move your arms into several different positions while blood flow is evaluated with Doppler ultrasound. This helps identify any changes in circulation caused by compression of the arteries or veins.
​
Frequently Asked Questions
Q: What is a thoracic outlet evaluation?
A: A thoracic outlet evaluation is a specialized vascular ultrasound that uses Doppler technology to assess blood flow through the subclavian arteries. The examination evaluates whether blood flow becomes restricted when your arms are placed in different positions, helping diagnose arterial Thoracic Outlet Syndrome (TOS).
​
Q: Why do I have to move my arms during the examination?
A: Thoracic Outlet Syndrome often occurs only when the arms are placed in certain positions. During the examination, you'll be asked to perform a series of arm and shoulder maneuvers so the sonographer can evaluate blood flow both at rest and during movement.
​
Q: Is the examination painful?
A: No. The examination is painless and non-invasive. You may feel gentle pressure from the ultrasound transducer and some mild discomfort if certain arm positions reproduce your symptoms, but there are no needles, injections, or incisions involved.
​
Q: How long does the examination take?
A: Most thoracic outlet evaluations take 45–60 minutes, depending on the number of positioning maneuvers required and the complexity of the study.
​
Q: Do I need to fast before my appointment?
A: No. Unlike many abdominal vascular ultrasound examinations, fasting is not required. You may eat, drink, and take your usual medications unless your healthcare provider has instructed you otherwise.
​
Q: Is there any radiation or contrast dye involved?
A: No. Thoracic outlet evaluation uses ultrasound and Doppler technology, which do not involve radiation or contrast dye.
​
Q: What conditions can this examination help diagnose?
A: This examination is primarily used to evaluate arterial Thoracic Outlet Syndrome (TOS) by determining whether the subclavian artery becomes compressed during arm movement. It may also help explain symptoms such as arm pain, numbness, coldness, fatigue, or reduced circulation during certain activities.
​
Q: When will I receive my results?
A: Your ultrasound images will be reviewed by a board-certified interpreting physician. A comprehensive diagnostic report will be generated promptly. If you were referred by a healthcare provider, your results will also be forwarded to their office for review and follow-up.
Q: Can I drive and return to my normal activities afterward?
​
A: Yes. Once your examination is complete, you may drive yourself home and resume your normal daily activities immediately.
​
Still Have Questions?
​
If you have additional questions about your thoracic outlet evaluation or would like more information before your appointment, our team is happy to help. Please don't hesitate to contact us—we're here to make your experience as comfortable and informative as possible.
Schedule Your Thoracic Outlet Syndrome (TOS) Vascular Evaluation
Scheduling your Thoracic Outlet Syndrome (TOS) Vascular Evaluation is quick and convenient. If you are experiencing arm pain, numbness, swelling, coldness, color changes, or symptoms that worsen with overhead activities, this examination can provide valuable information about blood flow through the arteries and veins of your neck, shoulder, and arm.
​
Our experienced ultrasound technologist performs every examination using advanced vascular ultrasound technology in a comfortable, patient-focused environment. A board-certified physician will interpret your study, and the results will be sent promptly to your referring provider. Self-pay appointments are also available if you do not have a referral.
​
Book your appointment online or contact our office if you have any questions. We're happy to help you determine whether a Thoracic Outlet Syndrome (TOS) Vascular Evaluation is the right examination for your needs.
​
If you experience sudden severe arm pain, significant swelling, a cold or pale arm, loss of sensation or movement, chest pain, or difficulty breathing, seek immediate medical attention or call 911, as these may be signs of a medical emergency.
Why Choose Alpha Vascular?
Experienced Sonographer
Board-Certified Interpretation
Advanced Ultrasound Technology
