NeoVista® MRI for Thoracic Outlet Syndrome

The NeoVista® MRI is the premiere imaging thoracic outlet syndrome test. At Vanguard Specialty Imaging, we can help you find a thoracic outlet syndrome specialist, get the best diagnosis for thoracic outlet syndrome, and learn options for thoracic outlet syndrome treatment.

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What is the Best Thoracic Outlet Syndrome Test?

At Vanguard Specialty Imaging, TOS is our passion. So we created the unique NeoVista® MRI for patients with TOS. We firmly believe NeoVista® is the best thoracic outlet syndrome test.

Experienced thoracic outlet syndrome specialists understand the limitations of the clinical diagnosis of thoracic outlet syndrome. When a specialist needs the best and most reliable thoracic outlet syndrome test for a patient, they turn to NeoVista®.

Thoracic outlet syndrome specialists across the country count on NeoVista® for accurate and detailed evaluation of TOS anatomy and pathology. Every study we perform is interpreted by Dr. Scott Werden, widely-recognized as the leader in the field of TOS imaging. No imaging study provides more useful and accurate information for thoracic outlet syndrome patients.

If you have TOS, you deserve the best thoracic outlet syndrome test. Don’t guess with TOS! Use NeoVista®.

Female young smiling doctor uses MRI of thoracic outlet syndrome
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Our TOS Patients Love Us!

We can tell you about our great diagnostic study or our success helping patients overcome TOS. But we will let our patients speak for themselves!

Dr. Werden developed an MRI protocol which he uses to image TOS. Dr. Mitchell Seruya and one of his colleagues at Cedars-Sinai both recommended that I receive imaging in accordance with Dr. Werden’s protocol. I was imaged many times (shoulder MRI, upper arm MRI, shoulder arthrogram, cervical spine MRI, brachial plexus MRI, brachial plexus MRN, many nerve conduction studies) before contacting Dr. Werden. Dr. Werden’s imaging protocol was the only imaging I received that produced positive evidence of brachial plexus impingement. –W. M., NeoVista Patient

Two short videos on Thoracic Outlet Syndrome and EMG

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TOS and EMG Part 1

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TOS and EMG Part 2

Thoracic outlet syndrome-Beautiful brunette woman with thoracic outlet syndrome in pain holding neck with both hands

What is Thoracic Outlet Syndrome?

Thoracic outlet syndrome (TOS) is a medical disorder that causes pain, numbness, tingling and weakness in the arms and hands, headaches, chest pain, and neck pain. TOS may also present as a blood clot, aneurysm, or arterial occlusion.

Compression of arteries, veins or nerves causes three types of thoracic outlet syndrome. TOS patients can develop permanent weakness, blood clot, aneurysm, or sudden loss of blood flow to the arm. While TOS can cause very serious disease, an experienced thoracic outlet syndrome specialist can speed up accurate diagnosis and treatment of TOS.

The thoracic outlet is the hollow space above your collarbone, between your shoulder and your neck. If you want to find your thoracic outlet, place your fingers on either side of your neck and slide down to the space above your collarbone.

Three vital structures pass through the thoracic outlet on each side. The subclavian artery distributes blood flow from your heart to the entire arm. The subclavian vein returns this blood to the heart. The brachial plexus forms a large nerve network from nerve roots that arises in the neck, controls all of the muscles of the arm, and transmits all sensation from the arm back to the spinal cord and brain. All of these structures pass between the collarbone and the first rib to connect the upper body, neck, and arm.

TOS is commonly classified into one of three types based on the structure that is affected. Doctors diagnose Neurogenic TOS when symptomatic compression of the brachial plexus occurs. Formation of a blood clot in the subclavian vein defines the classical diagnosis of venous TOS. Compression of the subclavian artery may result in aneurysm, blood clot formation, or arterial occlusion, which is known as arterial TOS.

Any process that compresses the nerves, arteries or veins of the thoracic outlet can cause thoracic outlet syndrome.

Common causes of TOS include trauma, especially motor vehicle accidents and falls, overuse at work, non-ergonomic computer use, and overhead athletics.

Many people are born with an extra rib or with anatomic variations of the soft tissues of the thoracic outlet. These variations cause narrowing of the thoracic outlet and contribute to thoracic outlet syndrome when other causes of TOS occur.

Females present with TOS much more frequently than males. TOS occurs most frequently in patients 20 to 50 years old.

Thoracic outlet syndrome was first described in 1818 in London, England. Since then, thousands of peer-reviewed articles regarding TOS have been written in the medical literature. Many notable physicians and researchers have studied TOS over the past 200 years. As a result, today we have great thoracic outlet syndrome tests and thoracic outlet syndrome treatments.

Thoracic Outlet Syndrome Videos

A picture is worth a thousand words. A video is priceless. Watch our educational TOS videos, featuring TOS specialists from around the country. Its a great way to start your educational journey!

Questions about TOS?

We can help!

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Thoracic Outlet Syndrome is a challenging disease. Join an upcoming live event and ask a physician expert questions. See www.toseducation.org for details.  #thoracicoutletsyndrome #dontguesswithtos
We know how difficult the Thoracic Outlet Syndrome diagnosis can be for a patient to navigate. Follow us here and watch all the videos at www.toseducation.org. #thoracicoutletsyndrome #dontguesswithtos
Does a negative ultrasound Indicate that the syndrome is not an appropriate diagnosis? Dr. Scott Werden discusses. 
#thoracicoutletsyndrome #thoracicoutletsyndromespecialist #thoracicoutletsyndromeexercises #thoracicoutletsyndromesurgery
Why does thoracic outlet syndrome often cause headaches? Dr. Scott Werden discusses.  #thoracicoutletsyndrome #thoracicoutletsyndromespecialist #dontguesswithtos
Great question that a patient asked Dr. Werden recently. Has his thinking on TOS and EMG changed over the past few years? #thoracicoutletsyndrome #thoracicoutletsyndromespecialist

Diagnosis of Thoracic Outlet Syndrome

The accurate and timely diagnosis of TOS makes a critical difference in treatment outcomes.

It is important for doctors to diagnose patients with arterial TOS or venous TOS promptly by finding a blood clot.

Neurogenic TOS mimics many other neurologic and orthopedic disorders, and remains a diagnostic challenge to many doctors. Fortunately, we have excellent thoracic outlet syndrome tests including MRI to help primary care physicians or TOS specialists make the accurate diagnosis of thoracic outlet syndrome.

TOS symptoms result from compression of nerves, arteries, or veins as they travel from the neck and chest to the arm. Compression of each of these vital structures causes a different group of symptoms.

Compression of the subclavian vein occurs in many people, often without symptoms of TOS. In certain groups of people, however, this compression results in the formation of a blood clot in the subclavian vein near the neck. As a result, blood flow from the arm to the heart is impaired, and these patients experience a number of striking symptoms:

  • Swelling of the affected arm
  • Dusky or blue color of the arm
  • New superficial veins of the affected shoulder and chest
  • Shortness of breath may occur if a blood clot travels to the lungs

Compression of the subclavian artery may occur to a mild extent in normal people. However, when this compression is severe and prolonged, damage of the underlying arterial wall develops. The damaged arterial wall may enlarge, forming an aneurysm, or a scar may form within the artery, narrowing the arterial diameter. These findings form the diagnosis of arterial TOS. Blood clots may form within the damaged arterial segment. These blood clots may break off and travel down the arm, blocking smaller arteries. A large blood clot at the site of damage may totally block blood flow to the arm. As a result of large or small blood clots in the arteries, areas of tissue death may occur. Therefore, the diagnosis of arterial TOS should be made promptly and accurately. Dramatic symptoms of arterial TOS include:

  • Coldness of the arm
  • Pale color of the arm
  • Loss of pulses
  • Weakness of the arm
  • Pain or tingling in the arm

While the symptoms of venous TOS and arterial TOS are dramatic and straightforward, the symptoms of Neurogenic TOS are often cryptic, for a number of reasons. First, there are many known anatomic variants of the thoracic outlet that may compress the brachial plexus. Second, there are significant changes of each thoracic outlet that occur with movement of the arms. Third, we know of many variants in the branching pattern of the brachial plexus. Fourth, even in the case of a typical brachial plexus branching pattern, the distribution of thousands of nerve fibers within the brachial plexus can vary highly. As a result of all of these variables, the exact point of compression and the underlying affected nerve component remains uncertain in most patients with Neurogenic TOS symptoms.

Given the expected broad range of possible symptoms in neurogenic TOS, patients often report the following symptoms:

  • Pain
  • Numbness
  • Tingling
  • Skin color changes
  • Weakness
  • Loss of coordination
When a doctor performs a physical examination on a patient with venous TOS, the diagnosis should be readily apparent. A large blood clot blocks the blood of the arm from returning to the heart. As a result, the physical examination would show one or more of the following:

  • Swelling of the arm
  • Skin discoloration, usually blue or purple
  • Loss of skin folds
  • New collateral veins over the affected shoulder or chest
  • Elevated venous angle
  • Palpable lump in the thoracic outlet near the neck

Physical examination on a patient with arterial TOS would quickly demonstrate evidence of arterial abnormality and blood clots causing arterial obstruction:

The clinical diagnosis of arterial TOS is usually quite dramatic, often with evidence of acute arterial insufficiency:

  • Pain
  • Loss of color
  • Loss of pulses
  • Weakness or paralysis
  • Tingling or pain in the arm

The physical examination of patients with arterial TOS may also show:

Aneurysm-pulsating mass in the thoracic outlet next to the neck
Chronic arterial insufficiency caused by stricture/narrowing of the artery
Evidence of fragmenting blood clots, causing spots on the fingers.

Given that neurogenic TOS symptoms are more complex, so is the physical examination in these patients. The standard neurologic examination often is entirely normal. Positive diagnostic signs may often be demonstrated by the physician on provocative maneuvers. There is a long history of provocative tests beginning in the late 19th century. Provocative tests are those tests where the examining physician has the patient move their arms, neck or shoulders into positions that create compression on the subclavian vein, subclavian artery, or brachial plexus with the intent of reproducing symptoms. In a patient with Neurogenic TOS symptoms, a physician may perform one or more of the following provocative tests:

  • Adson’s test
  • Wright test
  • Costoclavicular test
  • Roos’ test
  • Halstead maneuver
  • Upper limb neural tension test

It is important to remember that these clinical tests have limited sensitivity, specificity and accuracy. Some of these tests are based on compression of the veins or arteries, while a few are intended to demonstrate compression of the brachial plexus. Unfortunately, none of these provocative tests demonstrates the underlying anatomic abnormality in a patient with neurogenic TOS symptoms. However, when one or more are positive, an experienced TOS specialist would likely consider advanced imaging, such as the NeoVista® MRI examination.

Electrophysiologic Studies, ‘EPS,’ include electromyography (EMG) and nerve conduction velocity (NCV). These are commonly referred to as ‘EMG.’

EMG has been used for years in peripheral neuropathies, such as cubital tunnel syndrome and carpal tunnel syndrome. However, for a number of technical reasons, EMG has no significant value in neurogenic TOS. The compressed portions of the brachial plexus are too deep for direct examination, and too complex for indirect examination. Also, neurogenic TOS affects peripheral, smaller sensory nerves, while EMG measures larger, central motor nerves. Therefore, EMG studies often become positive only in late-stage neurogenic TOS.

Unfortunately, some authors refuse to recognize neurogenic TOS unless EMG demonstrates a positive result. In the opinion of many TOS specialists, EMG only shows late-stage neurogenic TOS. At this point late in the progression of the disease, treatment success rates are expected to be low. As in other entrapment neuropathies besides neurogenic TOS, doctors want to diagnose and treat early for better success rates.


Once your doctor arrives at the diagnosis of TOS, he or she may order imaging tests. Doctors use appropriate imaging tests for many disorders, and the appropriate imaging test for TOS can be particularly illuminating. Each of these tests has strengths and weaknesses.

The first medical x-ray was performed in 1895 X-rays were instrumental in demonstrating a cervical rib in some patients with neurogenic TOS or arterial TOS. They are still performed as a screening test today by some TOS specialists. However, x-rays are limited to two dimensions, they do not show important soft tissues, and we know that many TOS patients have completely normal x-rays. In addition, x-rays require a small to moderate amount of ionizing radiation.

Ultrasound uses very high frequency sound waves to create real-time images. Because the sonographer sees the structures of interest in real-time, motion and assessment of blood flow are easily performed. In patients with arterial TOS or venous TOS, ultrasound accurately shows blood flow in multiple arm positions with the patient lying down or sitting up. Ultrasound can also document a blood clot, and follow the progress of treatment to remove the clot. Unfortunately, in patients with neurogenic TOS, ultrasound shows limited utility. It can show the scalene muscles and brachial plexus to a limited extent. However, ultrasound is blind to the space between the collarbone and rib, a frequent point of compression of the brachial plexus. Ultrasound is extremely useful in guiding diagnostic or therapeutic injections in patients with neurogenic TOS. Ultrasound requires no ionizing radiation, and is extremely safe.

Catheter angiography and venography require a needle puncture of a large artery or vein, with subsequent administration of contrast. X-rays are used to follow the movement of contrast through these blood vessels. These tests show blood vessels with high resolution. However, they do not show the extrinsic causes of vessel compression, they are invasive, and they require high doses of ionizing radiation.

CT is widely available, shows bones in high detail, and shows blood vessels in 3 dimensions if contrast is administered. However, CT is middling at best for soft tissue evaluation, and requires a high ionizing radiation dose.

MRI provides the best soft tissue evaluation of any imaging modality in the thoracic outlet. MRA provides high-resolution images of arteries and veins. MRI creates 3 dimensional images in any plane. MRI/MRA requires no ionizing radiation. MRI does take longer to perform than CT, and requires expert radiologist involvement for optimum quality. MRI is our TOS test of choice. Learn about the NeoVista® MRI/MRA examination.

Patients with TOS recover more quickly when they are diagnosed and treated early in the course of the disease. Unfortunately, due to low awareness of TOS, doctors in many communities fail to recognize the disease. Therefore, the responsibility of achieving the diagnosis falls heavily on many patients.

Unlike many other diseases, no single primary medical specialty trains its practitioners to recognize and treat TOS. Many doctors receive no training at all regarding TOS. Expertise in TOS is scattered around the country amongst many different medical specialists.

For these reasons, we understand the importance of finding a TOS specialist as quickly and easily as possible. Once you understand what skills different specialists possess, you can then search for an experienced TOS specialist from our curated list. If your doctor tells you that you can’t have TOS because TOS isn’t real, or doesn’t know much about TOS, find a doctor who is a TOS specialist!


Mature silver-haired doctor with stethoscope diagnosing thoracic outlet syndrome

What our Patients Say

“I was imaged many times (shoulder MRI, upper arm MRI, shoulder arthrogram, cervical spine MRI, brachial plexus MRI, brachial plexus MRN, many nerve conduction studies) before contacting Dr. Werden. Dr. Werden’s imaging protocol was the only imaging I received that produced positive evidence of brachial plexus impingement.”

“Dr. Werden…is completely dedicated to this field and is exactly the kind of doctor every patient wants to have as part of their team.  I know what it’s like to ride the “medical merry-go-round” and now, thanks to Dr. Werden and NeoVista, I also know what it’s like to see a light at the end of the tunnel.”

“Dr. B: I’ve been very impressed with this TOS MRI protocol and the very detailed reports from Dr Werden. In my opinion, this is by far the most superior imaging modality for TOS.”

“I also wanted to thank you for the excellent videos you and your colleagues provide about TOS. To have so many medical experts in this area give up their time to educate patients and practitioners about TOS is truly incredible. I have read many articles and joined online forums that have only left me discouraged and confused, but your resources give me hope!”

“I’ve been consuming all of your videos online and am deeply grateful for the education they provide about TOS.”

“I wanted to send a big THANK YOU to Dr. Werden too, for all he does with his videos and educational outreach. It’s already made a world of difference to me, and I’m confident that’s the case for countless others. Dr. Werden, YOU ROCK.”

“When our 11-year old daughter fell onto her shoulder during a soccer game, little did we know that her life was going to change in that moment.  Suddenly she was unable to play basketball or soccer, her two favorite sports, and she could barely lift or move her arm without excruciating pain.  This high resolution MRI turned out to be a critical turning point in our daughter’s road to recovery – with a confirmed TOS diagnosis, a personal consultation with Dr. Werden to understand his findings, and access to a network of people in our area who specialize in this underrecognized condition, our daughter has improved significantly.”

“It has been a pleasure interacting with Dr. Werden and his team. I find Dr. Werden very passionate and knowledgeable about Thoracic Outlet Syndrome, TOS imaging, and the anatomy of the affected areas. The interpretation provided by Dr. Werden helped clarify my situation and potential explanations for my symptoms. Throughout the entire process, Dr. Werden has shown genuine interest in me as a patient and taken time to explain the procedure and my results and answer my questions. Highly recommended.”

“The NeoVista MRI-MRA for Thoracic Outlet Syndrome marked a turning point for me in what had previously been an endless search for diagnostic answers after being hit by a drunk driver.  This unique and highly specialized imaging protocol, designed by Dr. Scott Werden (a TOS pioneer and one of the leading advocates for improving TOS diagnosis and care), evaluates all of the relevant anatomy and is extremely detailed (my report was nine pages long!).  Dr. Werden is also extremely generous following the exam in terms of answering questions and consulting with my doctors (neurologists, etc.) — he is completely dedicated to this field and is exactly the kind of doctor every patient wants to have as part of their team.  I know what it’s like to ride the “medical merry-go-round” and now, thanks to Dr. Werden and NeoVista, I also know what it’s like to see a light at the end of the tunnel.”

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“I had a left first rib resection, scalenectomy and pec minor release with Dr Humphries on 2/22/22. I had an extra wide first rib and a bony bump where my anterior scalene attached and extensive brachial plexus scarring. I’m doing great! I woke up from surgery feeling better so much better. I will be proceeding with surgery on right side in a few months. Thank you for creating your specialized MRI, it was the tool that helped me determine surgery would yield a favorable outcome.”

“You will have a hard time finding a more compassionate, responsive doctor anywhere. He is so caring and wanted to help me find out what the source of my pain was. I had been dismissed by so many other physicians before him. He is a great doctor.”

“I have to let you know how absolutely grateful I am to all of you for helping me through a very rough time period in my life. I am back to doing most physical activities with my arms, even typing. I’ve opened my own consulting firm recently and it’s taking off. It feels like a new era for me, and I am full of hope. I want to truly thank all of you for what you’ve done for me. The work you do is life-changing.”

“I am looking forward to your next YouTube content. So far your channel has really helped direct me on the path to recovery. I’m not sure where I would be heading without it. Forever grateful!”

“Thanks to your MRI and Dr. Humphries’ incredible expertise I’m going in with full confidence it’s the right decision. Thank you for not only the education and peace of mind all your expertise has provided, but also for how approachable you’ve been throughout this difficult time. I just wanted to say thank you for all you do for me and others in a similar situation. I feel much less alone because of your work. It’s greatly appreciated!”

“Thank you again for your guidance and support during this process! I can’t thank you enough. I honestly would have been so lost without you. “

Female blue-eyed surgeon holding clipboard smiling slightly can treat thoracic outlet syndrome

Thoracic Outlet Syndrome Treatment

TOS can be successfully treated, especially if it is diagnosed quickly and accurately.

In general, doctors treat patients with arterial and venous TOS urgently, using surgical treatments.

On the other hand, doctors frequently treat patients with neurogenic TOS with conservative methods, before considering surgery.

Treatment of neurogenic TOS remains quite challenging. It is important to understand that no single treatment modality has been proven superior in all patients. Also understand that there are a large number of underlying mechanisms that cause neurogenic TOS.

Doctors make the primary treatment choice in patients with neurogenic TOS by pursuing either conservative or surgical treatment. Conservative treatment of neurogenic TOS may include physical therapy, pain medications, selective muscle injections, and chiropractic. Often, TOS specialists will pursue conservative treatment for 6 to 12 months before considering surgery. Many patients do well with a multi-modality plan incorporating several of these components.

Once the choice is made to undertake surgical treatment of TOS, patients have several options. Surgeons who are TOS specialists often focus on one of many available surgical techniques. Each technique creates its own advantages and disadvantages, and most TOS surgeons prefer one technique over all others. It is important for each TOS patient to understand these techniques, and to work with their surgeon to make the best choice.

Venous TOS is rare, accounting for 5% or less of all cases of TOS. Patients with venous TOS have a dramatic presentation, often showing up at an emergency room with a swollen, blue arm. In most cases, ultrasound demonstrates the blood clot in the subclavian vein, confirming the diagnosis.

At this point, doctors begin treatment of venous thoracic outlet syndrome in two phases. The first phase begins immediately, with the goal of promptly resolving the blood clot. Following successful clot resolution, the second goal is definitive and permanent treatment to prevent recurrent clots. This second phase usually involves surgery, with resection of the first rib to prevent compression of the subclavian vein. In addition, if the wall of the subclavian vein has been damaged by compression, the damaged segment is repaired.

Acute arterial occlusion may cause irreversible loss of function or actual gangrene of the affected area. Fortunately, arterial TOS is the rarest form of TOS, making up 1% or less of all TOS cases. Patients with arterial TOS may present to an emergency room with a true surgical emergency. If the blood flow to the arm is not promptly restored, the patient may lose all or part of the arm.

Similar to treatment of venousTOS, acute arterial thoracic outlet syndrome treatment involves two phases. First the surgeon must urgently restore blood flow to the arm. She can do so via drugs called thrombolytics, which dissolve blood clot, or by surgical removal of the clot. Once blood flow to the arm is restored, the surgeon can perform definitive treatment. In patients with arterial TOS, this entails specifically removing a first rib or cervical rib, to prevent future compression. During the same procedure, the surgeon will repair the damaged segment of the artery.

Patients with arterial TOS may also present with chronic arterial insufficiency. These patients usually suffer from limited blood flow to the arm, with complete loss of blood flow. Symptoms include very early fatigue and limited strength, due to the inability to increase blood flow on exercise. In these cases, the surgeon will remove the first rib or cervical rib, and will repair the damaged artery, but without the same urgency as in acute arterial occlusion.

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Thoracic Outlet Syndrome Education

The toseducation.org website is dedicated to TOS education for patients and doctors. Check out the latest video featuring TOS experts, and sign up for upcoming TOS education videos.