CT Findings of Double Aortic Arch in an Older Adult: Recognizing a Right-Dominant Complete Vascular Ring
Executive Answer
A double aortic arch is a congenital aortic arch anomaly in which both right and left aortic arches persist and form a vascular ring around the trachea and esophagus. In this case, a man in his 70s presented with chest pain and underwent CT pulmonary angiography (CTPA) to evaluate for pulmonary embolism. No acute pulmonary embolism was identified. Instead, CT revealed a right-dominant double aortic arch forming a complete vascular ring. The key radiologic task is not simply to recognize two arches, but to define arch dominance, branch-vessel anatomy, and the relationship of the vascular ring to the trachea and esophagus.
Why This Case Matters
A CT examination is ordered for a clinical reason, but the images often contain diagnostic information far beyond the initial question.
This case is a good example.
A man in his 70s presented with chest pain, and CTPA was performed to exclude acute pulmonary embolism. The pulmonary arteries showed no clear filling defect suggesting acute PE. However, careful evaluation of the thoracic vascular anatomy revealed an unexpected congenital abnormality: a right-dominant double aortic arch.
The two arches surrounded the tracheal and esophageal region, creating the configuration of a complete vascular ring.
This distinction matters because a vascular ring may be clinically silent, may cause respiratory or swallowing symptoms, or may become clinically relevant later in life.
The case also illustrates an important radiology principle:
The indication tells us what to look for first. It does not tell us what we are allowed to miss.
Clinical Scenario: Chest Pain, CTPA, and an Unexpected Diagnosis
The patient was a man in his 70s with chest pain.
In an older adult presenting with chest pain, important acute diagnoses may include:
Acute coronary syndrome
Pulmonary embolism
Aortic dissection
Pneumothorax
Pneumonia
Pleural disease
CT pulmonary angiography was therefore performed to evaluate for pulmonary embolism.
No acute pulmonary embolism was identified.
However, the CT revealed an important vascular anomaly: both right and left aortic arches were present, with the right arch larger than the left. The two arches surrounded the tracheal and esophageal region, producing a complete vascular-ring configuration.
The final anatomic diagnosis was:
Right-dominant double aortic arch resulting in a complete vascular ring.
The case does not establish that the vascular ring was definitively responsible for the patient's chest pain. That distinction is important. An imaging abnormality may be clinically significant without necessarily explaining every presenting symptom.
What Is a Double Aortic Arch?
A double aortic arch (DAA) is a congenital anomaly in which both the right and left aortic arches persist.
In the normal thoracic vascular configuration, there is a single dominant aortic arch. In a double aortic arch, both right and left arch structures remain.
When these arches pass around the trachea and esophagus and form a complete enclosure, they create a complete vascular ring.
The clinically important anatomy is therefore not simply:
two aortic arches
but rather:
two aortic arches + trachea + esophagus + vascular enclosure
The resulting vascular ring can compress the airway, the esophagus, or both.
Tracheal compression may produce:
Stridor
Wheezing
Chronic cough
Dyspnea
Recurrent respiratory symptoms
Esophageal compression may produce:
Dysphagia
Difficulty swallowing solid food
A sensation of food sticking
Feeding difficulties
Therefore, once a double aortic arch is recognized, the radiologist should continue asking:
Which arch is dominant?
Is the vascular ring complete?
Is the trachea compressed?
Is the esophagus compressed?
What is the branch-vessel anatomy?
Is there an associated vascular anomaly?
Axial Contrast-Enhanced Chest CT
Figure 1. Axial contrast-enhanced chest CT demonstrating a right-dominant double aortic arch.
Radiologic Interpretation
Axial CT is often the first place where the abnormal vascular configuration becomes apparent.
Instead of a single aortic arch, bilateral arch structures are seen around the central airway. The right aortic arch is relatively larger, while the left arch is smaller.
The important findings are:
Bilateral aortic arches
Right-sided arch dominance
Vascular structures surrounding the tracheal region
An anatomic configuration capable of producing a complete vascular ring
Axial imaging is particularly useful for identifying the initial clue.
The radiologist should not stop after noticing an unusual vessel. The vessels should be traced across consecutive slices to determine whether they represent true arch structures and how they relate to the trachea and esophagus.
In this case, CTPA was negative for acute pulmonary embolism, but the examination revealed the unexpected double aortic arch.
Coronal Contrast-Enhanced Chest CT
Figure 2. Coronal contrast-enhanced chest CT demonstrating the bilateral aortic arches and their spatial relationship.
Radiologic Interpretation
Coronal reconstruction provides a more intuitive understanding of the spatial relationship between the right and left aortic arches.
The right arch is dominant, while the left arch is relatively smaller.
The vascular structures form a configuration surrounding the tracheal and esophageal region, supporting the diagnosis of a complete vascular ring.
Coronal and other multiplanar reconstructions are particularly valuable when evaluating:
Arch direction
Arch continuity
Branch-vessel origins
The relationship between the arches and airway
The relationship between the arches and esophagus
This becomes especially important when the imaging is being considered for potential surgical planning.
Right-Dominant Double Aortic Arch
Figure 3. Double aortic arch resulting in a complete vascular ring, with right side dominant.
Radiologic Interpretation
Figure 3 demonstrates the defining anatomy of this case.
The right aortic arch is relatively large, while the left arch is smaller. Together, the two arches surround the trachea and esophagus, producing the characteristic anatomy of a complete vascular ring.
The diagnosis can therefore be stated precisely as:
Right-dominant double aortic arch resulting in a complete vascular ring.
This wording is more informative than simply stating "double aortic arch."
The diagnosis should communicate both:
arch dominance
and
vascular-ring configuration.
These details are important for understanding the anatomy and for subsequent clinical or surgical planning.
Why Can This Finding Be Missed?
The first diagnostic risk is satisfaction of search.
When a CTPA is ordered for suspected pulmonary embolism, the radiologist naturally concentrates on the pulmonary arteries.
If the pulmonary arteries are negative for PE, the study may be mentally classified as "negative."
But that is not an appropriate endpoint for thoracic CT interpretation.
The complete study should still include assessment of:
Aortic arch
Thoracic aorta
Major branch vessels
Trachea
Main bronchi
Esophagus
Mediastinum
Heart and pericardium
Pulmonary vasculature
Other relevant thoracic structures
The case therefore illustrates a fundamental principle:
A negative targeted examination does not necessarily mean a normal examination.
The original case specifically emphasizes that the purpose of CTPA and the actual diagnosis discovered on CT may be different.
The Imaging Reasoning: How to Diagnose Double Aortic Arch
When double aortic arch is suspected, a systematic approach is useful.
Step 1: Identify the Aortic Arch Configuration
Ask whether the patient has:
A conventional left aortic arch
A right aortic arch
Bilateral aortic arches
Do not diagnose a right aortic arch simply because a prominent vascular structure is seen on the right.
Step 2: Confirm Two True Arches
Trace the suspected vessels across multiple CT slices.
This is essential for distinguishing a true double arch from overlapping vascular structures or an unusual branch vessel.
Step 3: Trace the Branch Vessels
Identify the origins and courses of the major branch vessels.
In particular, determine which carotid and subclavian arteries arise from each arch.
Step 4: Evaluate the Trachea
Look for:
Vascular encasement
Narrowing
Displacement
Evidence of chronic compression
Step 5: Evaluate the Esophagus
Determine whether the esophagus is:
Enclosed within the vascular ring
Compressed
Deviated
Narrowed
Step 6: Determine Whether the Ring Is Complete
The critical question is whether the vascular structures form a complete ring around the trachea and esophagus.
Step 7: Determine Arch Dominance
In this case, the right arch is dominant and the left arch is relatively hypoplastic.
This should be explicitly stated because dominance can be relevant to treatment planning.
Step 8: Evaluate for Associated Anomalies
Other congenital cardiovascular or vascular abnormalities should be assessed when clinically appropriate.
The original case emphasizes this stepwise CT approach, including arch location, confirmation of two arches, branch-vessel tracing, tracheal and esophageal assessment, confirmation of a complete ring, determination of dominance, and assessment for associated anomalies.
Why Does Arch Dominance Matter?
Double aortic arch can be classified according to the relative size of the two arches.
The case describes three broad patterns:
| Pattern | Description | Reported proportion in the case material |
|---|---|---|
| Right-dominant | Larger right arch and smaller left arch | ~80% |
| Left-dominant | Larger left arch and smaller right arch | ~10% |
| Balanced | Similar-sized arches | ~10% |
The present case is right-dominant.
Arch dominance is clinically relevant because treatment planning generally requires identification of the arch that should be preserved and the smaller component that may be considered for division.
The case material emphasizes that dominance should therefore be explicitly reported on CT.
Double Aortic Arch vs. Other Vascular Rings
Several vascular anomalies can produce airway or esophageal compression.
Double Aortic Arch
Two aortic arches are present and can form a complete vascular ring.
This is the diagnosis in the present case.
Right Aortic Arch With Aberrant Left Subclavian Artery
A right aortic arch with an aberrant left subclavian artery can participate in vascular-ring formation, particularly when associated with ligamentous structures.
The key distinction is that the vascular architecture differs from a true double aortic arch.
Pulmonary Artery Sling
A pulmonary artery sling is another vascular anomaly that can compress the airway.
The abnormality involves an anomalous course of the left pulmonary artery rather than the presence of two persistent aortic arches.
Double Aortic Arch vs. Right Aortic Arch With Aberrant Left Subclavian Artery
| Feature | Double Aortic Arch | Right Aortic Arch + Aberrant Left Subclavian Artery |
|---|---|---|
| Aortic arch configuration | Right and left arches | Predominantly right-sided arch |
| Complete vascular ring | Directly formed by arch structures | May require ligamentous connection |
| Tracheal compression | Possible | Possible |
| Esophageal compression | Possible | Possible |
| Key CT task | Trace both arches | Trace branch vessels and aberrant vessel |
| Surgical planning | Define dominant and smaller arches | Define aberrant vessel and associated structures |
Therefore, the statement "a right-sided arch is present" is not sufficient to diagnose a right aortic arch.
The radiologist must establish whether a second true arch is present.
Why Can a Congenital Vascular Ring Present in an Older Adult?
A double aortic arch is strongly associated with pediatric vascular-ring disease.
However, the congenital anatomy may persist into adulthood without producing severe early symptoms.
The severity of symptoms can vary according to:
Arch size
Space between the arches
Tracheal diameter
Esophageal diameter
Surrounding soft tissue
Vascular elasticity
Age
Atherosclerotic changes
Respiratory mechanics
Swallowing mechanics
The original case discusses the possibility that age-related changes in vascular stiffness and the surrounding anatomy may influence the later clinical expression of a congenital vascular ring.
However, this should be interpreted carefully.
The presence of a vascular ring in an older adult does not prove that the ring caused the patient's presenting symptoms.
Clinical-radiologic correlation remains essential.
Clinical Symptoms: What Should Raise Suspicion?
A vascular ring becomes particularly relevant when symptoms correspond anatomically with airway or esophageal compression.
Potential respiratory symptoms include:
Inspiratory stridor
Wheezing
Chronic cough
Dyspnea
Recurrent respiratory infections
Potential gastrointestinal symptoms include:
Dysphagia
Difficulty swallowing solid food
Food sticking
Vomiting
Feeding difficulties
In adults, the symptoms may be less specific.
A patient may simply report:
"Food feels stuck when I swallow."
or
"I have had a chronic cough for years."
If CT demonstrates a vascular ring, these symptoms should prompt careful assessment of the tracheal and esophageal relationships.
The case material particularly emphasizes respiratory symptoms and stridor in pediatric patients while noting that adult symptoms can be more nonspecific.
Treatment: Anatomy, Symptoms, and Clinical Correlation
Treatment is not determined simply by the presence of a double aortic arch.
The important questions are:
Is the patient symptomatic?
Is there demonstrable tracheal compression?
Is there demonstrable esophageal compression?
What is the detailed arch anatomy?
Which arch is dominant?
Which vascular component could potentially be divided?
For patients with no or minimal symptoms, clinical observation may be considered.
When symptoms are clearly related to vascular-ring compression, surgical correction may be considered.
A general surgical principle is to preserve the dominant arch while addressing the smaller arch or other structures responsible for the ring.
However:
Right-dominant anatomy does not automatically determine one specific surgical approach.
The actual approach depends on:
Arch anatomy
Descending aortic position
Ligamentum arteriosum
Branch-vessel anatomy
Tracheal compression
Esophageal compression
Previous surgery
Overall patient anatomy
The original case specifically warns against mechanically equating "right-dominant" with a predetermined surgical approach.
Long-Term Airway Considerations
Chronic vascular compression may have consequences beyond the narrowing visible on a single CT study.
Prolonged airway compression can contribute to abnormal airway mechanics, including tracheomalacia.
Consequently, some patients may continue to have respiratory symptoms even after correction of the vascular ring.
This distinction is clinically important:
Anatomic correction ≠ guaranteed immediate functional normalization.
The long-term objective of treatment is therefore not merely to divide a vessel, but to relieve clinically significant airway or esophageal compression and minimize persistent functional impairment.
The case material notes that persistent respiratory symptoms, tracheal stenosis, or tracheomalacia may occur in some patients after treatment.
What Should the Radiologist Put in the Report?
A concise impression for this case could be:
Right-dominant double aortic arch forming a complete vascular ring around the trachea and esophagus. The left aortic arch is relatively hypoplastic. No evidence of acute pulmonary embolism.
This wording communicates the essential information:
The diagnosis
Arch dominance
Vascular-ring configuration
Relative size of the left arch
The negative PE finding
However, the degree of airway or esophageal compression should not be exaggerated if it is not clearly demonstrated.
The original case explicitly emphasizes that imaging findings should not be overstated beyond what is actually demonstrated.
Diagnostic Risk: The Hidden Lesson of This Case
The double aortic arch itself is rare.
But the more general lesson is highly relevant to everyday radiology.
A radiologist may be asked to answer:
"Is there a pulmonary embolism?"
But the actual examination may answer a much larger question:
"What important abnormalities are present throughout the imaged thorax?"
This creates several potential cognitive risks:
Satisfaction of Search
Once the primary target is excluded, the reader may prematurely stop searching.
Anchoring
The initial clinical suspicion may dominate image interpretation.
Perceptual Error
An unusual vessel may be seen but not recognized as a congenital arch anomaly.
Incomplete Field-of-View Review
Structures outside the primary target may receive insufficient attention.
The appropriate solution is not to blame individual clinicians.
It is to develop a systematic interpretation workflow.
Could AI Help Detect a Double Aortic Arch?
This case also provides an interesting example of how clinical AI might support radiology.
A future AI system could potentially assist with:
Aortic arch classification
Vessel segmentation
Detection of unusual vessel courses
Three-dimensional vascular reconstruction
Airway diameter measurement
Detection of possible tracheal compression
Detection of esophageal displacement
Structured reporting
Second-reader support
For example, an AI system analyzing a CTPA performed for suspected PE might identify an unexpected vascular pattern and generate an alert such as:
Possible congenital aortic arch anomaly. Review bilateral arch configuration and airway relationship.
This would be particularly useful when the primary indication is unrelated to congenital vascular disease.
However, this case does not establish the diagnostic performance of any specific AI product.
No sensitivity, specificity, accuracy, FDA clearance, or clinical outcome should be inferred from this case.
AI Failure Modes: Why Human Oversight Still Matters
AI assistance does not eliminate diagnostic responsibility.
Potential failure modes include:
False Negative
The system may fail to recognize an unusual congenital vascular configuration.
False Positive
Complex but normal vascular anatomy may be incorrectly flagged.
Anatomical Mislocalization
An AI model may identify an abnormal vessel but incorrectly determine its origin or course.
Domain Shift
Performance may change across scanners, institutions, reconstruction protocols, or patient populations.
Dataset Bias
Rare congenital anomalies may be underrepresented in training datasets.
Automation Bias
Radiologists may place excessive confidence in an AI result, whether positive or negative.
The appropriate clinical model is therefore:
AI as a second reader and workflow-support tool, not as the final authority on vascular anatomy.
Enterprise Imaging Workflow Perspective
If AI is eventually used for this type of detection, the workflow could conceptually involve:
DICOM → PACS → AI Orchestration → Vascular Anatomy Model → AI Inference → PACS Visualization → Radiologist → RIS → EHR/EMR →Clinical Decision Support
The key question is not simply whether AI can identify a double aortic arch.
The more meaningful enterprise question is:
Can AI reliably identify clinically relevant unexpected vascular anatomy at the right point in the radiology workflow without creating excessive false-positive alerts?
That is where clinical AI moves from an interesting algorithm to a potentially useful healthcare system.
Healthcare Workflow and System Value
A missed vascular anomaly can potentially lead to delayed recognition, additional diagnostic evaluation, or unnecessary repeat imaging.
However, the financial consequences should not be exaggerated.
This case does not provide sufficient evidence to assign a specific monetary cost, ROI, or productivity gain.
AI may contribute to this process, but only if it provides clinically meaningful information without generating excessive false-positive burden or interrupting radiology workflow.
Practical Radiology Algorithm
When reviewing a contrast-enhanced chest CT in which a double aortic arch is suspected, use this sequence:
This simple workflow helps transform an unexpected CT observation into a clinically meaningful diagnosis.
Practical Radiology Pearls
Pearl 1
A negative CTPA for PE is not a normal chest CT.
Pearl 2
Two aortic arches surrounding the trachea and esophagus should raise immediate consideration of a complete vascular ring.
Pearl 3
Do not stop at "double aortic arch." Determine which arch is dominant.
Pearl 4
Trace the branch vessels.
Pearl 5
Always assess the trachea and esophagus.
Pearl 6
Use multiplanar reconstruction to understand three-dimensional vascular anatomy.
Pearl 7
Do not dismiss a vascular ring simply because the patient is an adult.
Pearl 8
Do not assume that the vascular ring explains every symptom.
Pearl 9
Right-dominant anatomy does not automatically dictate a specific surgical approach.
Pearl 10
AI can redistribute attention, but it does not eliminate radiologist responsibility.
Common Diagnostic Pitfalls
Pitfall 1: "No PE, therefore normal."
Incorrect.
The CTPA may contain important non-PE findings.
Pitfall 2: "There is a right-sided arch, so this is a right aortic arch."
Not necessarily.
A true second arch must be excluded or confirmed.
Pitfall 3: Ignoring the esophagus
A vascular ring can produce clinically important esophageal compression.
Pitfall 4: Ignoring arch dominance
Dominance is relevant to anatomical characterization and treatment planning.
Pitfall 5: Assuming causality
The presence of a vascular ring does not prove that it caused the patient's chest pain.
Pitfall 6: Overtrusting AI
An AI-generated flag is a prompt for verification, not a substitute for vascular-anatomic reasoning.
FAQ
What is the key CT finding of a double aortic arch?
The key finding is the presence of both right and left aortic arches with a configuration that surrounds the trachea and esophagus. In this case, the right arch is dominant and the left arch is relatively smaller.
What makes a double aortic arch a complete vascular ring?
When the vascular structures form a complete enclosure around the trachea and esophagus, the anatomy constitutes a complete vascular ring.
What is the most important differential diagnosis?
A major differential diagnosis is a right aortic arch with an aberrant left subclavian artery. Careful tracing of the arch and branch-vessel anatomy is required to distinguish these entities.
Can double aortic arch be diagnosed in adults?
Yes. Although many symptomatic patients are diagnosed during childhood, congenital vascular-ring anatomy can persist into adulthood and may be discovered incidentally during imaging performed for another clinical indication.
What symptoms can a vascular ring cause?
Symptoms can result from airway or esophageal compression. Respiratory symptoms include stridor, wheezing, chronic cough, and dyspnea. Esophageal compression may cause dysphagia or difficulty swallowing.
Does every double aortic arch require surgery?
No. Management depends on symptoms, the degree of airway or esophageal compression, and the detailed vascular anatomy.
Does right-dominant anatomy determine the surgical approach?
No. The complete anatomy must be considered, including the descending aorta, ligamentous structures, branch vessels, and airway and esophageal relationships.
Can AI detect double aortic arch?
AI could potentially support vascular-anatomy detection and second-reader workflows, but this case does not establish the performance of any specific AI system.
Key Takeaways
The most important finding in this case is:
Right-dominant double aortic arch resulting in a complete vascular ring.
The patient underwent CTPA for chest pain and suspected pulmonary embolism. No acute PE was identified, but the CT revealed an important congenital vascular anomaly.
The three imaging views progressively demonstrate the diagnostic anatomy:
Figure 1 — Axial CT
→ identifies the bilateral arch structures and right-sided dominance.
Figure 2 — Coronal CT
→ clarifies the three-dimensional relationship of the two arches to the central airway and surrounding structures.
Figure 3 — Right-Dominant Double Aortic Arch
→ demonstrates the complete vascular-ring configuration surrounding the tracheal and esophageal region.
The practical radiology sequence is:
Two arches → trace the vessels → determine dominance → assess the trachea → assess the esophagus → confirm the complete ring → correlate clinically.
The broader lesson extends beyond vascular rings:
The clinical indication defines the starting point of image interpretation, not its endpoint.
Continue Learning
If you want to expand this topic into a broader medical-imaging knowledge network, the next useful topics include:
References
Alsenaidi K, Gurofsky R, Karamlou T, Williams WG, McCrindle BW. Management and outcomes of double aortic arch in 81 patients. Pediatrics. 2006;118(5):e1336-e1341. doi:10.1542/peds.2006-1097.
Backer CL, et al. Vascular rings. Seminars in Pediatric Surgery. 2016;25(3):165-175. doi:10.1053/j.sempedsurg.2016.02.009.
Hanneman K, Newman B, Chan F. Congenital variants and anomalies of the aortic arch. RadioGraphics. 2017;37(1):32-51. doi:10.1148/rg.2017160033.
Lee WJ, Shah YK, Ku A, Patel NR, Maldjian PD. Double aortic arch in an asymptomatic adult. Cureus. 2023;15(4):e37437. doi:10.7759/cureus.37437.
Secco GG, Marino PN, Carriero A, De Luca G. Silent double aortic arch coincidentally found during cardiac catheterization in elderly man. Congenital Heart Disease. 2011;6(1):74-76. doi:10.1111/j.1747-0803.2010.00429.x.
Worhunsky DJ, Levy BE, Stephens EH, Backer CL. Vascular rings. Seminars in Pediatric Surgery. 2021;30(6):151128. doi:10.1016/j.sempedsurg.2021.151128.
Saran N, et al. Vascular rings in adults: Outcome of surgical management. Annals of Thoracic Surgery. 2019;108(4):1217-1227. doi:10.1016/j.athoracsur.2019.04.097.
Evans EW, et al. Vascular ring diagnosis and management: Notable trends over 25 years. Clinical Medicine Insights: Cardiology. 2016;7(6):717-720. doi:10.1177/2150135116661279.
Ctori E, et al. Morphology of vascular ring arch anomalies influences prognosis and management. Archives of Disease in Childhood. 2021;106(5):477-483. doi:10.1136/archdischild-2020-319388.
Yaynishet YA, et al. Symptomatic vascular ring due to double aortic arch: A report of two cases. Radiology Case Reports. 2025;20(1):97-100. doi:10.1016/j.radcr.2024.09.137.
Medical Disclaimer
This article is intended for medical education and informational purposes only. It does not replace professional medical diagnosis, treatment, or individualized clinical judgment. Patients should discuss symptoms, imaging findings, and treatment decisions with an appropriately qualified healthcare professional.
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