Each of the three types of TOS results from a different mechanism. Thus, imaging tests in TOS patients are specialized and focused. Imaging should demonstrate the compressed nerves, arteries or veins, as well as the mechanism of compression.
Patients with neurogenic TOS present a challenge to many doctors, even TOS specialists. Imaging tests specifically designed for patients with neurogenic TOS can confirm or rule out the doctor’s clinical diagnosis. Additionally, MRI can show all the structures of the thoracic outlet, both normal and abnormal, that cause neurogenic TOS.
In the past, doctors have used various tests, ranging from x-rays to direct angiography to CT scans, to help understand this disease. But we firmly believe that MRI provides the greatest diagnostic value for these patients. We would like to help you understand the imaging diagnosis of neurogenic TOS.
Most doctors quickly recognize the signs and symptoms of a patient presenting with venous TOS. A large blood clot blocks blood flow in the veins draining the arm. Arm swelling, color changes, and new superficial veins appear. Since the clinical diagnosis can be made promptly, imaging diagnosis of venous TOS focuses on proving the presence of a blood clot. Imaging can also guide the doctors who dissolve this blood clot. Doctors select from ultrasound, direct venogram, CT, or MRI for this purpose.
Following the urgent treatment of this blood clot, imaging provides detailed information about the structures that initially caused the blood clot. Often, there is a prominent tendon or ligament that compresses and damages the vein in certain arm positions. MRI demonstrates these soft tissues with great detail.
Patients with arterial TOS frequently present with acute arterial occlusion, which is a surgical emergency. Doctors need to remove this clot and restore blood flow urgently. Imaging tests can prove the presence and extent of the arterial blood clot. Imaging tests also enable doctors to dissolve the clot.
Following emergent restoration of blood flow to the arm, doctors use imaging tests to demonstrate arterial damage, such as an aneurysm or stenosis. Further, imaging tests show the structures outside the artery that caused the damage to begin with. This mechanism may only be apparent with the patient’s arms elevated. Read more about the imaging tests that provide vital information in patients with arterial TOS.