NeoVista® is a unique and dedicated MRI examination for TOS patients
NeoVista® helps to diagnose and define TOS. We provide a unique service to TOS patients and their doctors. Learn more on this page how NeoVista® provides added value.
Why do we need a specialized MRI examination for TOS?
Doctors find it very challenging to diagnose thoracic outlet syndrome on clinical examination. Typical clinical tests like Adson’s test or the Wright test do not have good accuracy. Some doctors use scalene injections to help with the diagnosis. There are significant questions surrounding these tests.
And even when a doctor makes an accurate diagnosis of thoracic outlet syndrome, the underlying cause is very difficult to prove. Are abnormal scalene muscles causing compression of the brachial plexus? Do the rib and clavicle approach too closely? Is there a blood clot? Is there an aneurysm?
What would the ideal diagnostic imaging test for TOS look like?
The ideal diagnostic imaging test for TOS would accurately assess the following:
Fully show the normal anatomy of each thoracic outlet
Evaluate the brachial plexus on each side, including variant branching, compression, or tension
Show the subclavian artery on each side, and evaluate for stenosis, aneurysm, or blood clot
Demonstrate the subclavian vein on each side, including the presence of compression, stenosis, or blood clot
Show any extrinsic structures that compress the brachial plexus, subclavian artery, or subclavian vein on each side, such as scalene anomalies or fibrous bands
Evaluate cervical ribs or abnormal first ribs
Demonstrate changes that occur on arm motion
Quantify and compare movement of the shoulder girdle on each side
Rule in or rule out any alternative diagnosis, including cervical spine disease
Confirm the presence of TOS
Why is this information so helpful?
First, confirming or ruling out TOS is a critical starting point.
Second, understanding which form or forms of TOS are present is critical. This information can help doctors decide whether to begin conservative therapy or go to surgery.
Third, if surgery is indicated, a surgeon would want to know ahead of time what structures need to be removed, and what structures need to be repaired. For example, operating on a patient with a subclavian artery aneurysm would require a different surgeon than would isolated decompression the brachial plexus. On the other hand, removing a cervical rib requires a different approach from releasing an abnormal anterior scalene muscle.
Fourth, the presence of any other cause of nerve compression or vascular damage would change treatment decisions.
No clinical test can provide this information in such great detail. Even if a doctor diagnoses TOS on clinical examination, they cannot know the underlying anatomic causes without dedicated and detailed imaging.
NeoVista® combines all of the individual ideal imaging components into a single comprehensive test. The full NeoVista® examination includes:
Detailed anatomy of each thoracic outlet
Images of each brachial plexus
Angiograms of both subclavian arteries and their branches
Venograms of the subclavian veins, jugular veins, and chest veins
Soft tissue anomalies, including scalene muscles, muscle variants, and fibrous bands
Demonstrating cervical ribs or anomalous first ribs
Changes that occur on arm motion
Proprietary method to measure shoulder girdle movement on each side
Evaluation of the cervical spine and upper thoracic spine
Confirming the clinical diagnosis of TOS when it is present; confirming alternate diagnoses when present
Most MRI imaging centers can perform single components from this list. For example, some imaging centers will perform an MRA (MR angiogram) of the subclavian arteries to diagnose TOS.
MRA of bilateral subclavian arteries
Now, this image demonstrates two important details. First, the image shows both subclavian arteries with good detail. Most imaging centers using standard injected gadolinium contrast material will achieve good quality on one side only. For example, Raptis, Thompson, et al published in 2016 that, “The intravenous catheter should be placed on the side opposite the symptoms…”. They and other centers can only consistently achieve good imaging quality on one side, and must avoid the symptomatic side. But what do they do if the patient has bilateral symptoms? The NeoVista® examination overcomes this limitation. One injection, one set of images, excellent quality.
Second, not only are the arteries bright, all other tissues are darkened as much as possible. While this is fine for evaluating the arteries, there is no way to tell if extrinsic structures are compressing the arteries. Since TOS is caused by extrinsic structures in the thoracic outlet, this is a a significant limitation. The NeoVista® examination acquires all essential imaging components in one comprehensive study. Thus, the radiologist can match abnormal arteries with abnormal extrinsic structures seen on other images.
Some imaging centers will perform isolated images of the brachial plexus, sometimes referred to as an MR neurogram.
Bilateral Brachial Plexus
Again, you can see the brachial plexus is bright, and the background is dark. So, it is almost impossible to know if a structure is compressing or stretching the brachial plexus. NeoVista® overcomes this limitation.
It is important to remember that none of these individual imaging components can tell the story by itself. TOS is complex and multi-factorial, and multiple imaging components are necessary to tell the entire story.
And that is exactly what NeoVista® achieves. The NeoVista® examination includes every one of these components in a single comprehensive study, taking only 45 minutes. The US Patent and Trademark Office has awarded three patents to date for this unique technology.