From the Guidelines
Thoracic outlet syndrome is diagnosed through a combination of clinical evaluation and diagnostic tests, including a thorough medical history, physical examination, provocative tests, and imaging studies such as X-rays, MRI, CT scans, and ultrasound, as recommended by the American College of Radiology 1.
Diagnostic Approach
The diagnosis of thoracic outlet syndrome (TOS) begins with a thorough medical history and physical examination, where the doctor looks for symptoms like pain, numbness, or weakness in the neck, shoulder, arm, or hand. Several provocative tests may be performed, including:
- Adson's test (checking pulse while turning head and breathing deeply)
- The elevated arm stress test (EAST)
- The Roos test (holding arms in specific positions to reproduce symptoms)
Imaging Studies
Imaging studies are often used to confirm the diagnosis, including:
- X-rays to identify cervical ribs or bone abnormalities
- MRI or CT scans to visualize soft tissue compression
- Ultrasound to assess blood flow
- Nerve conduction studies and electromyography may help evaluate nerve function and rule out other conditions
- Angiography might be performed in vascular cases to visualize blood vessel compression
Recommendations
According to the American College of Radiology, the following imaging studies are usually appropriate for the initial and follow-up imaging after surgery or intervention for patients with TOS:
- For neurogenic TOS: radiography of the chest and MRI without and with IV contrast of the chest or MRI without IV contrast of the chest 1
- For venous TOS: radiography of the chest and US duplex Doppler of the subclavian artery and vein, CT with IV contrast of the chest, or catheter venography of the upper extremity 1
- For arterial TOS: radiography of the chest and CTA with IV contrast of the chest, MRA without and with IV contrast of the chest, US duplex Doppler of the subclavian artery and vein, or arteriography of the upper extremity 1
Key Considerations
The diagnosis of TOS can be challenging because symptoms overlap with other conditions, so a comprehensive approach combining clinical findings and appropriate diagnostic tests is essential for accurate identification of thoracic outlet syndrome. The choice of imaging study depends on the specific type of TOS and the clinical presentation of the patient. Consultation with a radiologist may be useful at the time of examination ordering to optimize the study for the prevailing clinical symptom 1.