Aortic Arch

When radiologists mention the aortic arch in your report, they’re referring to a segment of your body’s largest artery that connects the ascending and descending portions of your aorta. This segment delivers oxygen-rich blood to your head, neck, and upper body. Understanding what the aortic arch is and why it’s being evaluated can help you better understand your imaging and to discuss findings with your doctor.

What Is the Aortic Arch?

The aortic arch is the curved portion of the main blood vessel leaving your heart. After blood is pumped out of the heart’s left ventricle, it travels through the ascending aorta, then curves through the aortic arch before continuing down through the descending aorta to deliver oxygen-rich blood to the rest of your body.

This arch-shaped section sits above the heart in the upper chest and forms an important landmark in chest imaging. The arch typically gives rise to three major blood vessels that supply blood to your head, neck, and arms.

Why Radiologists Examine the Aortic Arch

Imaging of the aortic arch helps identify various conditions. Common reasons for examining the aortic arch include:

• Evaluating for aneurysms (abnormal bulging)
• Checking for dissection (tearing of the vessel wall)
• Assessing for atherosclerosis (plaque buildup)
• Looking for congenital abnormalities
• Monitoring known aortic conditions
• Planning surgical interventions

Aortic Arch Imaging Techniques

Several imaging methods can visualize the aortic arch, each with specific advantages for different clinical situations.

CT Angiography

CT angiography (CTA) provides detailed cross-sectional images of the aortic arch and surrounding structures. This technique uses X-rays and intravenous contrast material.  This technique also allows the creation of 3D reconstructions.

CTA excels at:

• Rapid imaging in emergency situations
• Detecting aortic dissections
• Measuring aneurysm dimensions precisely
• Identifying calcified plaques
• Evaluating branch vessels

MRI of the Aortic Arch

Magnetic resonance imaging (MRI) uses powerful magnets and radio waves to create detailed images without radiation.

Ultrasound Evaluation

While less commonly used for comprehensive aortic arch assessment, ultrasound techniques like transesophageal echocardiography (TEE) can provide valuable information about:

• Aortic valve function
• Blood flow patterns
• Wall movement
• Quickly assessing for dissection at the bedside
• Monitoring during certain surgical procedures

Common Aortic Arch Findings on Imaging

Radiology reports might describe the following conditions affecting the aortic arch.

Aortic Arch Aneurysm

An aneurysm represents abnormal dilation of the aortic arch. Reports typically describe:

• Location within the arch
• Maximum diameter measurements
• Comparison to prior studies
• Presence of thrombus (blood clot)
• Involvement of branch vessels

Aortic Dissection

This life-threatening condition involves a tear in the inner lining of the aorta, allowing blood to flow between the layers of the vessel wall. Imaging findings include:

• An intimal flap dividing the true and false lumens
• Extent of dissection
• Involvement of branch vessels
• Signs of compromised blood flow
• Potential complications like rupture

Atherosclerotic Disease

Plaque buildup in the aortic arch appears as irregular thickening or calcifications along the vessel wall. Reports may note:

• Degree of calcification
• Distribution pattern
• Stenosis (narrowing) of branch vessels
• Ulcerated plaques that increase stroke risk
• Overall burden of disease

Aortic Arch Variants

Normal anatomic variations are common and include:

• Bovine arch (common origin of brachiocephalic and left common carotid arteries)
• Right-sided aortic arch
• Aberrant subclavian artery
• Direct origin of the left vertebral artery from the arch
• Presence of additional small branches

Clinical Significance of Aortic Arch Findings.

When to Be Concerned

Not all aortic arch findings require immediate intervention. Factors that influence clinical decision-making include:

• Size of aneurysms
• Rate of growth over time
• Presence of symptoms like chest pain
• Family history of aortic disease
• Associated genetic conditions
• Overall cardiovascular health

Follow-up Recommendations

Depending on the findings, recommendations can include:

• Regular imaging surveillance at specific intervals
• Referral to cardiovascular specialists
• Blood pressure management
• Genetic testing
• Lifestyle modifications
• Surgical consultation

Conclusion

The aortic arch plays an important role in your cardiovascular system.  Modern imaging tests provide detailed information about the arch, helping doctors diagnose conditions ranging from common variations to life-threatening emergencies. When your radiology report mentions the aortic arch, understanding the basic terminology and findings can help you participate actively in decisions about your care.

References

1. https://www.ncbi.nlm.nih.gov/books/NBK499911/
2. https://radiopaedia.org/articles/aortic-arch?lang=us
3. https://my.clevelandclinic.org/health/body/17058-aorta-anatomy