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KEY FACTS

Terminology
- Right aortic arch (RAA) - Aortic arch located to right of trachea
- Common variations - RAA with aberrant left subclavian artery (ALSA) ± Kommerell diverticulum (KD) - RAA with mirror-image branching
Imaging
- Radiography - Right paratracheal nodular opacity and indentation of right tracheal margin on frontal chest radiograph - KD: Retroesophageal opacity with indentation of posterior tracheal margin on lateral chest radiograph
- CT - RAA with ALSA with retroesophageal course ± KD - RAA with mirror-image branching - RAA with left descending aorta with retroesophageal aortic segment
Top Differential Diagnoses
- Double aortic arch
- Mediastinal mass
Clinical Issues
- RAA with ALSA - Most patients are asymptomatic - Some patients with KD may have dysphagia or stridor
- RAA with mirror-image branching - Cyanotic congenital heart disease
- RAA with left descending aorta (circumflex aorta) - Ductus ligament between pulmonary artery and ALSA constitutes vascular ring
- Treatment - Symptomatic RAA with ALSA/KD may require division of ligamentum via left thoracotomy

TERMINOLOGY

Abbreviations
- Right aortic arch (RAA)
Synonyms
- Right arch
Definitions
- Aortic arch located to right of trachea, crossing right main stem bronchus
- Common variations - RAA with mirror-image branching - RAA with aberrant left subclavian artery (ALSA) ± Kommerell diverticulum (KD) - KD - Saccular dilatation at level of ALSA - Implies left-sided ligamentum arteriosum and vascular ring
- Uncommon variations - RAA with left descending aorta (circumflex aorta) - RAA with isolation of left subclavian artery - RAA with aberrant brachiocephalic artery - RAA with unilateral absence of pulmonary artery

IMAGING

General Features

Best diagnostic clue

- Indentation of right tracheal margin due to paratracheal mass

Radiographic Findings

Radiography

- General features for different variations
        - Right paratracheal opacity
        - Indentation of right tracheal margin
                  - Normally, left aortic arch (LAA) has indentation along left tracheal margin
- RAA with ALSA
        - + KD
                  - Retroesophageal nodular opacity
                  - Indentation of posterior tracheal margin
                  - Can simulate left aortic arch (LAA) on frontal projection
- RAA with mirror-image branching
        - ± dextrocardia
        - High association with congenital heart disease
                  - Tetralogy of Fallot
                  - Truncus arteriosus
                  - Tricuspid atresia
                  - Transposition of great arteries
- RAA with unilateral absence of pulmonary artery
        - Hypoplastic ipsilateral hemithorax with contralateral hyperinflation
        - Absent or grossly ↓ pulmonary vascular markings

Fluoroscopic Findings

Esophagram

- Indentations seen only when ALSA present
- Frontal projection: Oblique filling defect coursing from right inferior to left superior
- Lateral view: Posterior indentation
        - Large posterior indentation: Aortic diverticulum

CT Findings
- RAA with ALSA (most common) - 4 great vessels from left to right in following order: Left common carotid, right common carotid, right subclavian, ALSA - ALSA with retroesophageal course - ± KD (bulbous dilatation at origin of ALSA)
- RAA with mirror-image branching - 3 great vessels from left to right in following order: Left brachiocephalic, right common carotid, right subclavian - Ancillary findings of congenital heart disease (e.g., tetralogy of Fallot and truncus arteriosus) - Rarely, blind aortic diverticulum (similar to KD) - Difficult to differentiate from double aortic arch (DAA) with atretic left arch - Inferior tethering of left subclavian artery may suggest DAA with atretic left arch - Both RAA with mirror-image branch and aortic diverticulum and DAA with atretic left arch are vascular rings
- RAA with left descending aorta (circumflex aorta) - Retroesophageal aortic segment - Variants - Mirror-image branching - ALSA - Left descending thoracic aorta
- RAA with isolation of left subclavian artery - 3 great vessels from left to right in following order: Left carotid, right carotid, right subclavian - Left subclavian artery is blind ended, connected to aortic arch by ductus ligament
- RAA with aberrant brachiocephalic artery - Retroesophageal course of left carotid and left subclavian arteries
- RAA with unilateral absence of pulmonary artery - RAA with ALSA or mirror-image branching - Pulmonary artery terminates within 1 cm of its origin - More peripheral pulmonary arteries are present - Pulmonary hypertension - Ancillary findings: Bronchiectasis, mosaic attenuation, and honeycombing
MR Findings
- Same accuracy as CT to assess for variations of vascular anatomy
- Absence of ionizing radiation is significant advantage, especially in younger patients
- MR superior to CT in setting of complex congenital heart disease
- Can be evaluated with contrast or noncontrast MR angiography

Echocardiographic Findings

Echocardiogram

- May determine great vessels pattern (mirror-image branching vs. ALSA), although there are acoustic window limitations
- Origin of ALSA usually well seen, especially in presence of KD
- Helpful in further characterizing associated congenital heart disease

Imaging Recommendations

Best imaging tool

- Characterization of different variations of RAA successfully achieved with either MR or CT
- MR superior in fully characterizing congenital heart disease in setting of RAA with mirror-image branching

DIFFERENTIAL DIAGNOSIS

Double Aortic Arch
- Differentiation on radiography may be not possible, as KD can simulate LAA
- CT and MR are diagnostic - Patent RAA and LAA with larger RAA and smaller LAA - Double aortic arch (DAA) with atretic LAA - Inferior tethering of left subclavian artery - Aortic diverticulum more common in DAA
Mediastinal Mass
- Right paratracheal lymphadenopathy and esophageal neoplasm can simulate RAA on chest radiography
- Focal and smooth indentation of right tracheal margin classically seen in RAA on chest radiography
- CT or MR better delineate mediastinal masses and differentiate from RAA

PATHOLOGY

General Features

Etiology

- Congenital derangement
- Embryologic considerations
        - Causes of arch anomalies
                  - Interruption of normal parts
                  - Lack of interruption of parts that normally regress
        - LAA (normal aortic arch) develops from interruption distal to right subclavian artery
        - RAA with ALSA develops from interruption between left common carotid and left subclavian arteries
        - RAA with mirror-image branching develops from interruption distal to left subclavian artery

Associated abnormalities

- RAA with ALSA ± KD: Low incidence of congenital heart disease
- RAA with mirror-image branching: High incidence of congenital heart disease (~ 98%)
        - RAA in 25% of patients with tetralogy of Fallot
        - RAA in 25-50% of patients with truncus arteriosus
        - Transposition of great vessels
- RAA rarely associated with unilateral absence of pulmonary artery

Gross Pathologic & Surgical Features
- KD - Remnant of embryonic left 4th aortic arch - Implies ipsilateral (left) ductus ligament and resulting vascular ring (often loose) - Embryologically different from ALSA
- ALSA - Can arise directly from descending aorta or from DK - Rarely lies anterior to trachea (5%)

CLINICAL ISSUES

Presentation

Most common signs/symptoms

- RAA with ALSA
        - Most patients asymptomatic
        - Presence of KD constitutes vascular ring, often loose
        - Patients with KD may have dysphagia or stridor
- RAA with mirror-image branching
        - Cyanotic congenital heart disease
        - If associated with blind aortic diverticulum (but no ALSA), constitutes loose vascular ring that may be symptomatic (i.e., dysphagia, stridor)
- RAA with left descending aorta (a.k.a. circumflex aorta)
        - Ductus ligament between pulmonary artery and ALSA constitutes vascular ring, often loose, that may be symptomatic (i.e., dysphagia, stridor)

Demographics

Age

- The tighter the vascular ring, the earlier it becomes symptomatic

Epidemiology

- RAA present in 0.1% of adults
        - RAA with ALSA is most common variant

Natural History & Prognosis
- Determined mostly by coexisting congenital heart disease
- Tracheomalacia, residual stenosis, and vascular compression are common after repair, which most children eventually outgrow, but some require additional surgery
- RAA with ALSA: Association with progressive stenosis of ALSA has been described in pediatric population
- RAA with mirror-image branching: High association with stenosis of common carotid arteries or subclavian arteries
Treatment
- Symptomatic RAA with ALSA/KD - Requires division of ligamentum via left thoracotomy - Aortopexy may be needed additionally - When associated with complete cartilaginous tracheal ring: Resection and tracheal reconstruction
- RAA with mirror-image branching - Treatment of associated congenital heart disease

DIAGNOSTIC CHECKLIST

Consider
- RAA with mirror-image branching pattern must be evaluated for congenital heart disease
- RAA with ALSA but no KD is usually incidental finding (i.e., asymptomatic)
- RAA with ALSA and KD constitutes vascular ring - While frequently asymptomatic, few patients may present with dysphagia &/or stridor
Image Interpretation Pearls
- RAA variant may be impossible to establish on chest radiography
- MR and CT equally accurate to determine pattern of branching in patients with RAA

c4b1211f-7ef2-4e83-8e0d-6ad126698010

References

Selected References

Anatomy

Coronary Anatomy

Cardiac/ANATOMY:e4b09a25-666c-486b-b040-a9af4ae560b4

Cases

{'cases': [{'authors': [{'key': 'b00d2bdb-66e1-41ed-90b4-c52904f4d598', 'value': 'Seth Kligerman, MD, MS'}], 'caseVersionId': '203a2db9-3625-4686-8399-cf8c28252385', 'description': 'PA radiograph (#1) shows a right-sided aortic arch (arrow), which indents the right side of the trachea (curved arrow). Notice that the descending thoracic aorta is to the right of the spine (open arrow). Lateral radiograph (#2) shows no evidence of a retroesophageal density to suggest an aberrant left subclavian artery. Also notice the small median sternotomy wires from prior cardiac surgery when the patient was an infant (arrow). Axial CT image at the level of the arch (#3) confirms the presence of a right-sided aortic arch (arrow). No aberrant left subclavian artery is present. Axial image above the arch (#4) shows 4 vessels originating from the superior aspect of the aortic arch. These are the right subclavian artery (black arrow), right common carotid artery (curved arrow), left common carotid artery (open arrow), and left subclavian artery (white arrow). This orientation with absence of an aberrant left subclavian artery confirms mirror image branching. Coronal maximum intensity projection reformat (#5) shows the right subclavian artery (black arrows), right common carotid artery (curved arrow), left common carotid artery (open arrow), and left subclavian artery (white arrow) arising from the superior aspect of the aortic arch. The origin of the right subclavian artery is partially obscured by contrast in the superior vena cava. Coronal maximum intensity projection reformat (#6) shows the right-sided descending thoracic aorta (arrow). Axial CT image (#7) shows right ventricular dilatation and a right-sided descending thoracic aorta (arrow), both associated with tetralogy of Fallot.', 'history': 'Patient who underwent surgical repair for tetralogy of Fallot when 7 months old. ', 'imagePoolId': 'f9e793dc-db2d-4b00-97d2-a507aa1ca9dd', 'name': 'Right arch, mirror image branching, tetralogy', 'teachingPoint': None, 'demographics': '14 Years old male'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}], 'caseVersionId': '4653106c-5a00-4f0a-95e0-9261e606fca8', 'description': 'Typical radiographic and CT features of bronchiectasis from immotile cilia syndrome.\n\nFrontal radiograph (#1) shows situs inversus: right aortic arch (arrow) and dextrocardia (curved arrow). Hiatal hernia (open arrow). Lateral radiograph (#2) shows hiatal hernia (arrow) and possible bronchiectasis (open arrows). NECT (#3-5) shows diffuse bronchiectasis (open arrows).', 'history': 'Chronic cough.', 'imagePoolId': '275d846a-6dd9-41f4-a759-81e5cd2a01fc', 'name': 'Bronchiectasis', 'teachingPoint': None, 'demographics': '59 Years old female'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}], 'caseVersionId': '48579a91-0ef2-4c4b-8c1d-cdbc611e860b', 'description': 'Typical radiographic and CT features of bronchiectasis from immotile cilia syndrome.\n\nRadiograph (#1) shows situs inversus: right aortic arch (curved arrow), dextrocardia (open arrow), right-sided gastric bubble (black arrow) and bronchiectasis left lower lobe (open arrow). Lateral radiograph (#2) shows left middle lobe atelectasis (arrows). NECT (#3) shows bronchiectasis and left middle lobe atelectasis (white arrow). Right-sided empyema (black arrows). NECT (#4) shows situs inversus. Radiograph different time (#5) shows left lower lobe bronchiectasis (arrow).', 'history': 'Chronic cough.', 'imagePoolId': '6083a376-687a-423c-bf5f-12fbdc5c47b3', 'name': 'Bronchiectasis', 'teachingPoint': None, 'demographics': '45 Years old male'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}, {'key': '55c0cff5-49cc-4f10-af0f-9bbe4379c141', 'value': 'Howard Mann, MD'}], 'caseVersionId': '4c3ff2ad-5bc1-4d91-b0b3-b15ae55af634', 'description': 'Typical radiographic features of right aortic arch.\n\nRadiographs (#1, 2) demonstrate abnormal course of the aortic arch as well as descending aorta (arrows). Note the absence of aortic knob in normal position (curved arrow, #1).', 'history': 'Incidental finding. ', 'imagePoolId': '5fd06a4d-700c-44f5-bba6-25e9ad8f483b', 'name': 'Right paratracheal mass', 'teachingPoint': None}, {'authors': [{'key': 'fff9b5a0-8473-401a-8da6-d1366705ec01', 'value': 'Jeffrey P. Kanne, MD'}], 'caseVersionId': '5cc33a02-bc3e-4cdb-ac1d-dc3a521f8bc1', 'description': "PA radiograph (#1) shows a well-defined mediastinal mass (black arrows) displacing the trachea to the left. No aortic arch is apparent on the left. The descending aorta (open black arrows) can be seen coursing along the right of the mediastinum, crossing to left just above the diaphragm, and entering the abdomen. Lateral radiograph (#2) shows a well-defined round mass (black arrows) in the retrotracheal (Raider's) triangle displacing the trachea anteriorly.\n\nAxial CECT (#3) and coronal thin-slab CT maximum-intensity projection (#4) show a right aortic arch (white arrows) with an aberrant left subclavian artery (open white arrow, #3) arising from a large diverticulum of Kommerell (curved white arrow, #3).", 'history': 'Acute chest pain.', 'imagePoolId': 'a10a28d7-2530-4292-adce-9d33dd60cc1b', 'name': 'Right aortic arch with aberrant left subclavian artery', 'teachingPoint': None, 'demographics': '49 Years old male'}, {'authors': [{'key': '924986ad-eb92-480e-88ae-1f3d01d70763', 'value': 'James G. Ravenel, MD'}], 'caseVersionId': 'ea283083-a2d4-4b44-b794-34cce427948f', 'description': 'Typical radiographic features of right paratracheal mass due to right aortic arch.\n\nRadiographs (#1,2) show right aortic arch (arrows) deviating the trachea to the left. On lateral view (#2), aberrant left subclavian courses posterior to trachea, bowing posterior wall anteriorly (curved arrow).', 'history': 'Pre-operative examination', 'imagePoolId': '68d80a8d-e2fe-414b-ba19-f2ca6b23d271', 'name': 'Right paratracheal mass', 'teachingPoint': None, 'demographics': '70 Years old male'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}], 'caseVersionId': 'ea90705e-d115-452d-9950-d569bd302c08', 'description': 'Typical radiographic features of right paratracheal mass from right aortic arch.\n\nRadiographs (#1,2) show right aortic arch (arrow) shifting the trachea to the left. Absence of normal aortic mogul on the left (open arrow). Lateral radiograph (#3) is normal.', 'history': 'Asymptomatic.', 'imagePoolId': '5b3fafeb-9ecd-476c-bae3-724541e6a07a', 'name': 'Right paratracheal mass', 'teachingPoint': None, 'demographics': '34 Years old female'}, {'authors': [{'key': 'b00d2bdb-66e1-41ed-90b4-c52904f4d598', 'value': 'Seth Kligerman, MD, MS'}], 'caseVersionId': '8fa27665-18fc-48f7-a70e-a2103c305859', 'description': "PA radiograph (#1) shows a right-sided aortic arch (black arrow), which is indenting on the right wall of the trachea (open arrow). Also notice the prominent vascular structure to the left of the trachea at the same level (curved arrow). Although this structure appears contiguous with the aorta, it does not indent the left wall of the trachea, suggesting that it is either anterior or posterior to the trachea. The thoracic aorta is tortuous and descends to the right of the spine (white arrow). Lateral radiograph (#2) shows a large vascular structure displacing the trachea anteriorly (arrow). This structure appears contiguous with the shadow of the descending thoracic aorta (open arrow). \n\nAxial CT images at the level of the ascending aorta (#3-4) show a right-sided aortic arch (arrows), which displace the trachea to the left. Additionally, there is a large diverticulum of Kommerell (black open arrows) coursing posterior to both the trachea and esophagus (curved arrows), displacing both structures anteriorly. This diverticulum of Kommerell gives rise to the left subclavian artery (white open arrows). This constellation of findings represents a right aortic arch with an aberrant left subclavian artery. Incidentally, the origin of the left subclavian artery was stenotic due to atherosclerotic disease. Axial CT image more inferior (#5) shows the right-sided descending thoracic aorta (arrow). Also notice the esophageal stent and the markedly thickened esophagus (open arrow) due to the patient's esophageal cancer. Sagittal CT reformat (#6) shows the large diverticulum of Kommerell (arrow) coursing posterior to the trachea and esophagus, displacing both structures anteriorly. Coronal reformat (#7) demonstrates aortic morphology with the right-sided aortic arch (arrow) and the large diverticulum of Kommerell (open arrow), which gives rise to the left subclavian artery (curved arrow).", 'history': 'Patient with history of esophageal cancer undergoes yearly CT examination to evaluate for disease recurrence. ', 'imagePoolId': '312d0e10-4e9a-4279-858a-53ffa0ad43b0', 'name': 'Aberrant left subclavian', 'teachingPoint': None, 'demographics': '64 Years old male'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}, {'key': 'a5d3a4eb-860a-429a-b9a9-6897de9309c2', 'value': ' HELIMED, Katowice, Poland'}], 'caseVersionId': 'a7b35684-4e2b-4f58-93b9-0cccdde60f9b', 'description': 'Typical radiographic and CT features of right aortic arch.\n\nAP localizer (#1) show right aortic arch (arrows). Normal shadow of aortic knob is absent (curved arrow). CT image (#2) shows right aortic arch (arrow). CT images (#3-5) show the course of the descending aorta on the right (arrows).', 'history': 'Incidental finding. ', 'imagePoolId': '14b7f023-a2af-4694-ae96-14a5bb196304', 'name': 'Right paratracheal mass', 'teachingPoint': None, 'demographics': '70 Years old male'}], 'caseType': 'typical', 'name': 'TYPICAL'}
{'cases': [{'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}], 'caseVersionId': '7062283f-41be-4456-80ab-d1b33a559bc1', 'description': 'Variant CT features of right aortic arch, aberrant left subclavian artery, obstructing the esophagus causing dysphagia lusoria.\n\nCECT (#1-7) shows right aortic arch (arrows, #2-7), aberrant left subclavian artery (open arrows, #1-4), and dilated esophagus (curved arrow, #1,2).', 'history': 'Dysphagia lusoria.', 'imagePoolId': '06362dc6-87e3-44f6-8ad8-de64b798f2ae', 'name': 'Dilated esophagus', 'teachingPoint': None, 'demographics': '48 Years old male'}, {'authors': [{'key': '612e745f-e298-40da-8326-de2c383c4fc1', 'value': 'Jud W. Gurney, MD, FACR'}], 'caseVersionId': 'e4bc6099-3a98-416d-8ecc-c33685ee8894', 'description': 'Variant right cervical arch and vascular ring causing tracheomalacia.\n\nRadiographs (#1-4) shows right cervical aortic arch (arrows). CECT (#5, 6) shows right cervical aortic arch (arrow), aberrant left subclavian artery (open arrow), and tracheal compression (curved arrows). Sagittal reconstruction (#7) shows tracheal compression by aberrant left subclavian artery (arrow). Three-dimensional reconstruction of the trachea (#8) shows posterior narrowing (arrow). Three-dimensional reconstruction (#9) shows aberrant left subclavian (open arrows) and ductus ligament (arrow). \n\nComment: Dilated origin of aberrant subclavian known as diverticulum of Kommerell. In the case, with cervical arch vascular structures crowded into narrow inlet causing compression and tracheomalacia.', 'history': 'Dyspnea on exertion, wheezing, "asthma."', 'imagePoolId': 'ce528799-4648-472e-ab95-075b09653bf4', 'name': 'Cervical arch', 'teachingPoint': None, 'demographics': '24 Years old female'}], 'caseType': 'variant', 'name': 'VARIANT'}

Images

Selected Images

PA chest radiograph in a patient with right aortic arch (RAA) and aberrant left subclavian artery (ALSA) without Kommerell diverticulum (KD) shows RAA as a right paratracheal nodular opacity with right tracheal indentation.

Lateral chest radiograph in the same patient shows the normal configuration of the trachea . ALSA with KD can show indentation of posterior tracheal margin; however, differentiation from ALSA without KD is not always possible.

Axial chest CTA in an asymptomatic patient with RAA , ALSA , and descending thoracic aorta on the right reveals an incidentally noted persistent left superior vena cava draining into the coronary sinus.

Coronal reformation CTA in the same patient shows ALSA arising as the last aortic branch. There is no KD. The lack of KD usually indicates absence of a ductus ligament on the side of the anomalous subclavian artery (SCA); therefore, this does not constitute a vascular ring.

PA chest radiograph in an asymptomatic patient with RAA, ALSA, and KD shows RAA as a right paratracheal nodular opacity with an indentation of the right tracheal margin.

Lateral chest radiograph in the same patient shows an indentation of the posterior tracheal margin , which relates to the presence of a KD. This suggests that mirror-image branching is not present. Note that KD implies the presence of a vascular ring, which may or may not be symptomatic.

Composite axial chest CTA in a patient with RAA, ALSA, and KD demonstrates RAA and ALSA/KD with mild dilatation of the proximal esophagus superior to the KD.

Sagittal chest CTA reformation in the same patient shows posterior tracheal indentation by the KD . KD implies the presence of a ductus ligament contralateral to the arch and, hence, constitutes a vascular ring. KD predisposes to dysphagia when present (dysphagia lusoria).

Oblique coronal chest CTA reformation in the same patient shows a bulbous configuration of the origin of the ALSA, a classic feature of KD. KD is a consequence of the presence of a ductus arteriosus on the side of the SCA. Pathophysiologically, patients with KD may have symptoms (e.g., dysphagia lusoria) related to a vascular ring completed by the ligamentum arteriosum.

Anterior and posterior CTA 3D reformations in the same patient with RAA, ALSA , and KD show the bulbous appearance of the KD.

Composite axial chest CTA shows RAA with a retroesophageal left descending aorta (circumflex aorta) , blind aortic diverticulum , and mirror-image branching.

Composite chest CTA coronal reformation in the same patient shows RAA , left brachiocephalic trunk , blind aortic diverticulum , and left descending aorta . The circumflex aorta implies a vascular ring, which often is loose and occasionally symptomatic.

Axial chest CTA in an infant with RAA with mirror-image branching and aortic diverticulum with stridor shows a right-sided descending thoracic aorta .

Posterior 3D CTA in the same patient is shown. Despite the presence of a blind aortic diverticulum , this case represents an RAA, not a double aortic arch (DAA) with atretic left aortic arch (LAA), given the lack of inferior tethering of the left SCA. (Courtesy R. Reina, MD.)

Axial chest CECT shows RAA with isolation of the SCA. Note the presence of prominent arterial collaterals .

Coronal chest CECT in the same patient shows the blind origin of the left SCA with a cord-like structure extending from it to the aortic wall representing a ductus ligament , which can clinically represent a loose ring. Note extensive arterial collaterals , which supply the left SCA.

Additional Images

PA chest radiograph in a patient with RAA , ALSA, and KD is shown. Frequently, when an RAA is associated with a KD, the latter can sometimes simulate the presence of a normal LAA, thus appearing as a DAA on frontal chest radiograph. An important clue for differentiation is that the KD does not exert an indentation on the left lateral margin of the trachea, as would be expected with a coexistent LAA.

Frontal DSA aortogram in a patient with RAA also shows ALSA and KD .

Coronal chest CTA reformation in a patient with RAA, ALSA, and KD shows mild normal indentation of the right tracheal margin from the RAA. In this case, there is no significant stenosis of the trachea.

Frontal projection esophagram in a pediatric patient with RAA and ALSA shows an oblique indentation on the esophageal lumen, which is caused by the ALSA. Note that esophagrams are often useful when assessing vascular rings in symptomatic patients.

Axial CTA shows RAA with mirror-image branching in a patient with tetralogy of Fallot.

Radiograph shows a leftward position of the trachea in a patient who is rotated to the left.

Coronal rendition in the same patient shows a takeoff of the left SCA from the KD.

Changing the opacity setting of this rendition reveals the presence of an ALSA .

Axial CTA in an asymptomatic infant with stridor shows an RAA and ALSA . Note mild tracheal narrowing and also bilateral superior venae cavae.

Coronal CTA volume rendition shows an RAA with no tracheal compression.

Axial CTA in an asymptomatic 49-year-old woman shows an RAA and aneurysmally dilated KD .

42 KiB Raw Permalink Blame History

KEY FACTS

Terminology

Imaging

Top Differential Diagnoses

Clinical Issues

TERMINOLOGY

Abbreviations

Synonyms

Definitions

IMAGING

General Features

Best diagnostic clue

Radiographic Findings

Radiography

Fluoroscopic Findings

Esophagram

CT Findings

MR Findings

Echocardiographic Findings

Echocardiogram

Imaging Recommendations

Best imaging tool

DIFFERENTIAL DIAGNOSIS

Mediastinal Mass

PATHOLOGY

General Features

Etiology

Associated abnormalities

Gross Pathologic & Surgical Features

CLINICAL ISSUES

Presentation

Most common signs/symptoms

Demographics

Age

Epidemiology

Natural History & Prognosis

Treatment

DIAGNOSTIC CHECKLIST

Consider

Image Interpretation Pearls

References

Selected References

Anatomy

Coronary Anatomy

Cases

Images

Selected Images

Additional Images

42 KiB

Raw Permalink Blame History