Imaging diagnosis of neurogenic TOS
Imaging of patients with neurogenic TOS provides valuable information to the TOS specialist. While a TOS specialist may strongly suspect that his or her patient has neurogenic TOS, the clinical examination has poor sensitivity and accuracy. Therefore, several outstanding questions must be answered. Firstly, can compression or tension of the brachial plexus be proven? Second, is there intrinsic disease of the brachial plexus? Third, can alternative diagnoses, such as a herniated disc, be ruled out? Fourth, what are the exact anatomic structures that cause compression or tension of the brachial plexus? Fifth, does arm motion contribute to compression? Finally, what other structures are involved, such as arteries or veins?
Fortunately, a dedicated TOS MRI can answer all of these questions and more. Done properly and interpreted by a TOS-specialized radiologist, MRI provides extremely valuable information to the TOS specialist.
How does a TOS specialist use this data?
It is important to remember that clinical tests used by TOS specialists do not possess very good accuracy. Therefore, while a TOS specialist may suspect neurogenic TOS, he or she cannot easily prove the diagnosis. So, MRI proof of brachial plexus compression or tension provides critical data. Also, rarely, inflammation or trauma of the brachial plexus may cause a similar clinical picture as neurogenic TOS. MRI can clearly rule out such brachial plexus damage.
TOS specialists often find a challenge in distinguishing the symptoms of neurogenic TOS from those caused by cervical spine disease. The NeoVista® MRI examination always includes images of the cervical spine, just for this purpose.
Once the diagnosis of neurogenic TOS is confirmed, treatment decisions can be based on the underlying cause. Patients who have extra ribs or abnormal ribs may need surgery as the primary treatment. On the other hand, patients with soft tissue abnormalities or abnormalities of shoulder motion can respond quite well to conservative treatment. Additionally, given the anatomic complexity of the thoracic outlet, surgeons may use the MRI to plan their surgical goals before the procedure. In most surgical specialties, surgeons have refined and minimized their procedures over many decades. Many surgeons plan to get every pathologic element resolved, while minimizing their effect on normal structures. MRI is widely used in other surgical fields for this purpose. In a similar fashion, MRI may be used in TOS patients for the same reason.
Most neurogenic TOS patients experience symptoms or worsen their symptoms when performing activities. If these changes can be evaluated, conservative treatment plans can be tailored to a specific patient. The NeoVista® MRI uses a proprietary quantitative method of evaluating arm motion on each side, in each patient. We believe this data adds a level of detail that a TOS specialist would find quite important and helpful.
The same process that damages the brachial plexus may compress or damage arteries or veins. Should such compression or damage exist, the surgical plan might require a second, specialist surgeon. MRI provides this data before surgery, which could change the surgical plan.