Intravascular US (IVUS) may be used as an adjunct in the postoperative setting to evaluate residual lumen size and presence of webs and has been shown to detect a higher degree of stenosis compared with venography alone [33]. CT Chest For noncontrast chest CT, the goal is to demonstrate anatomical narrowing that could cause vascular compression. Findings include effacement of fat within the respective space and distortion or narrowing of the space with provocative or stress positioning. Given the enhanced visualization of vascular structures with contrast, chest CT with IV contrast is preferred for evaluation of vTOS, and the acquisition is typically performed with a contralateral antecubital injection of contrast material. Chest CT without IV contrast may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. However, chest CT with IV contrast has the advantage of providing assessment of vascular patency, which is a potential complication in the postintervention setting for patients with vTOS. CTA Chest CTA is performed to evaluate arterial compression and is therefore of limited use in the evaluation of vTOS. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization. CTV Chest CTV is performed to evaluate venous compression in neutral and elevated arm positions. Venous compression is often present with abduction in asymptomatic patients, and therefore this finding alone may be insufficient to diagnose vTOS. Venous thrombosis and presence of collateral venous circulation essentially bypassing the thoracic outlet confirms the existence of hemodynamically significant vTOS [1].
Thoracic Outlet Syndrome. Intravascular US (IVUS) may be used as an adjunct in the postoperative setting to evaluate residual lumen size and presence of webs and has been shown to detect a higher degree of stenosis compared with venography alone [33]. CT Chest For noncontrast chest CT, the goal is to demonstrate anatomical narrowing that could cause vascular compression. Findings include effacement of fat within the respective space and distortion or narrowing of the space with provocative or stress positioning. Given the enhanced visualization of vascular structures with contrast, chest CT with IV contrast is preferred for evaluation of vTOS, and the acquisition is typically performed with a contralateral antecubital injection of contrast material. Chest CT without IV contrast may be performed in the postintervention setting to evaluate interval changes in the thoracic outlet and assess adequate decompression. However, chest CT with IV contrast has the advantage of providing assessment of vascular patency, which is a potential complication in the postintervention setting for patients with vTOS. CTA Chest CTA is performed to evaluate arterial compression and is therefore of limited use in the evaluation of vTOS. If there are overlapping symptoms, review of the other Variants in this document may help with protocol optimization. CTV Chest CTV is performed to evaluate venous compression in neutral and elevated arm positions. Venous compression is often present with abduction in asymptomatic patients, and therefore this finding alone may be insufficient to diagnose vTOS. Venous thrombosis and presence of collateral venous circulation essentially bypassing the thoracic outlet confirms the existence of hemodynamically significant vTOS [1].