The Retrotracheal Space: Normal Anatomic and Pathologic Appearances1
Tomás Franquet, MD,
Jeremy J. Erasmus, MD,
Ana Giménez, MD,
Santiago Rossi, MD and
Rosa Prats, MD
1 From the Department of Radiology, Hospital de la Santa Creu i Sant Pau, Universidad Autónoma de Barcelona, Avda Sant Antoni M. Claret 167, 08025 Barcelona, Spain (T.F., A.G., R.P.); the Department of Radiology, M. D. Anderson Cancer Center, Houston, Tex (J.J.E.); and the Department of Radiology, Fundación Dr Enrique Rossi, Buenos Aires, Argentina (S.R.). Presented as an education exhibit at the 2001 RSNA scientific assembly. Received February 22, 2002; revision requested April 2 and received May 29; accepted June 12. Address correspondence to T.F. (e-mail: 19429tfc@comb.es).
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Figure 1a. Normal radiologic anatomy of the retrotracheal space. (a) Lateral chest radiograph shows the lung tissue posterior to the trachea as a radiolucent triangular space (*). This space extends from the thoracic inlet superiorly to the aortic arch inferiorly and is bounded posteriorly by the spine. The anterior edge of the scapula (arrow) projects over the space and may sometimes be misidentified as the posterior border of the retrotracheal space (arrowheads). (b) Computed tomographic (CT) scan shows the normal retrotracheal space occupied by a dilated esophagus.
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Figure 1b. Normal radiologic anatomy of the retrotracheal space. (a) Lateral chest radiograph shows the lung tissue posterior to the trachea as a radiolucent triangular space (*). This space extends from the thoracic inlet superiorly to the aortic arch inferiorly and is bounded posteriorly by the spine. The anterior edge of the scapula (arrow) projects over the space and may sometimes be misidentified as the posterior border of the retrotracheal space (arrowheads). (b) Computed tomographic (CT) scan shows the normal retrotracheal space occupied by a dilated esophagus.
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Figure 2a. Left-sided aortic arch with an aberrant right subclavian artery in an asymptomatic 53-year-old man. (a) Close-up view of a lateral chest radiograph shows an area of increased opacity in the retrotracheal space and displacement of the trachea anteriorly (arrows). (b) Contrast material-enhanced CT scan shows an aberrant right subclavian artery that arises as the last branch of a left-sided aortic arch posterior to the esophagus.
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Figure 2b. Left-sided aortic arch with an aberrant right subclavian artery in an asymptomatic 53-year-old man. (a) Close-up view of a lateral chest radiograph shows an area of increased opacity in the retrotracheal space and displacement of the trachea anteriorly (arrows). (b) Contrast material-enhanced CT scan shows an aberrant right subclavian artery that arises as the last branch of a left-sided aortic arch posterior to the esophagus.
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Figure 3a. Aberrant right subclavian artery in a 64-year-old man with esophageal carcinoma and dysphagia. (a) Close-up view of a lateral chest radiograph shows an area of increased opacity in the retrotracheal region (arrows). (b) Contrast-enhanced CT scan shows the retrotracheal space occupied by an aberrant right subclavian artery that courses posterior to an esophageal carcinoma.
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Figure 3b. Aberrant right subclavian artery in a 64-year-old man with esophageal carcinoma and dysphagia. (a) Close-up view of a lateral chest radiograph shows an area of increased opacity in the retrotracheal region (arrows). (b) Contrast-enhanced CT scan shows the retrotracheal space occupied by an aberrant right subclavian artery that courses posterior to an esophageal carcinoma.
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Figure 4a. Right-sided aortic arch with an aberrant left subclavian artery in a 58-year-old man. (a) Posteroanterior chest radiograph shows a right-sided thoracic aorta. (b) Lateral esophagogram shows an aberrant left subclavian artery as a masslike area of increased opacity in the retrotracheal space. The artery displaces the trachea anteriorly and leaves its classic posterior impression on the esophagus. (c) Contrast-enhanced CT scan reveals the origin of the anomalous left subclavian artery.
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Figure 4b. Right-sided aortic arch with an aberrant left subclavian artery in a 58-year-old man. (a) Posteroanterior chest radiograph shows a right-sided thoracic aorta. (b) Lateral esophagogram shows an aberrant left subclavian artery as a masslike area of increased opacity in the retrotracheal space. The artery displaces the trachea anteriorly and leaves its classic posterior impression on the esophagus. (c) Contrast-enhanced CT scan reveals the origin of the anomalous left subclavian artery.
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Figure 4c. Right-sided aortic arch with an aberrant left subclavian artery in a 58-year-old man. (a) Posteroanterior chest radiograph shows a right-sided thoracic aorta. (b) Lateral esophagogram shows an aberrant left subclavian artery as a masslike area of increased opacity in the retrotracheal space. The artery displaces the trachea anteriorly and leaves its classic posterior impression on the esophagus. (c) Contrast-enhanced CT scan reveals the origin of the anomalous left subclavian artery.
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Figure 5a. Right-sided aortic arch with an aneurysmal left subclavian artery in an asymptomatic 74-year-old man. (a) CT scan shows a partially calcified, aneurysmal retrotracheal left subclavian artery. An azygous lobe (arrowheads) is seen adjacent to a right-sided aortic arch. (b) Contrast-enhanced CT scan shows the aneurysm without associated mural thrombus.
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Figure 5b. Right-sided aortic arch with an aneurysmal left subclavian artery in an asymptomatic 74-year-old man. (a) CT scan shows a partially calcified, aneurysmal retrotracheal left subclavian artery. An azygous lobe (arrowheads) is seen adjacent to a right-sided aortic arch. (b) Contrast-enhanced CT scan shows the aneurysm without associated mural thrombus.
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Figure 6a. Double aortic arch that was incidentally discovered in an asymptomatic 58-year-old man. (a) Frontal chest radiograph reveals bilateral paratracheal masses that represent double aortic knobs. Focal wall calcification is present in the right aortic arch (arrowheads). (b) Coronal T1-weighted MR image shows right and left aortic arches. (c) On a sagittal T1-weighted MR image, the retrotracheal space is obscured by both aortic arches.
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Figure 6b. Double aortic arch that was incidentally discovered in an asymptomatic 58-year-old man. (a) Frontal chest radiograph reveals bilateral paratracheal masses that represent double aortic knobs. Focal wall calcification is present in the right aortic arch (arrowheads). (b) Coronal T1-weighted MR image shows right and left aortic arches. (c) On a sagittal T1-weighted MR image, the retrotracheal space is obscured by both aortic arches.
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Figure 6c. Double aortic arch that was incidentally discovered in an asymptomatic 58-year-old man. (a) Frontal chest radiograph reveals bilateral paratracheal masses that represent double aortic knobs. Focal wall calcification is present in the right aortic arch (arrowheads). (b) Coronal T1-weighted MR image shows right and left aortic arches. (c) On a sagittal T1-weighted MR image, the retrotracheal space is obscured by both aortic arches.
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Figure 7a. Progressive enlargement of an aneurysm of the transverse aortic arch in an 82-year-old man. (a) Unenhanced CT scan shows a mass that was caused by a large aortic aneurysm and fills the retrotracheal space. The esophagus (arrowhead) is displaced to the right and posterior to the mass. (b) Contrast-enhanced CT scan shows a penetrating atherosclerotic ulcer and a contained rupture or mediastinal hematoma (arrow).
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Figure 7b. Progressive enlargement of an aneurysm of the transverse aortic arch in an 82-year-old man. (a) Unenhanced CT scan shows a mass that was caused by a large aortic aneurysm and fills the retrotracheal space. The esophagus (arrowhead) is displaced to the right and posterior to the mass. (b) Contrast-enhanced CT scan shows a penetrating atherosclerotic ulcer and a contained rupture or mediastinal hematoma (arrow).
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Figure 8a. Esophageal atresia in a newborn. Frontal (a) and lateral (b) radiographs show an air-distended pouch in the retrotracheal space (arrows in a) that deforms the adjacent portion of the trachea. A radiopaque tube has been placed on the blind pouch of the proximal portion of the esophagus (arrow in b). (Case courtesy of Elida Vázquez, MD, Hospital Vall D’Hebrón, Barcelona, Spain.)
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Figure 8b. Esophageal atresia in a newborn. Frontal (a) and lateral (b) radiographs show an air-distended pouch in the retrotracheal space (arrows in a) that deforms the adjacent portion of the trachea. A radiopaque tube has been placed on the blind pouch of the proximal portion of the esophagus (arrow in b). (Case courtesy of Elida Vázquez, MD, Hospital Vall D’Hebrón, Barcelona, Spain.)
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Figure 9a. Esophageal duplication cyst in a 23-year-old woman in whom a mass was incidentally found at chest radiography. (a) Lateral chest radiograph reveals an area of increased opacity in the retrotracheal region and anterior displacement of the trachea. (b) CT scan shows a well-circumscribed mass with water attenuation adjacent to the esophagus. The appearance and location of the mass are typical for an esophageal duplication cyst.
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Figure 9b. Esophageal duplication cyst in a 23-year-old woman in whom a mass was incidentally found at chest radiography. (a) Lateral chest radiograph reveals an area of increased opacity in the retrotracheal region and anterior displacement of the trachea. (b) CT scan shows a well-circumscribed mass with water attenuation adjacent to the esophagus. The appearance and location of the mass are typical for an esophageal duplication cyst.
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Figure 10a. Zenker diverticulum in a 54-year-old man with dysphagia and cough. (a) Posteroanterior chest radiograph shows abnormal widening of the superior portion of the mediastinum. An air-fluid level is also seen (arrows). (b) CT scan shows a large retrotracheal diverticulum with an air-fluid level due to retained alimentary content.
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Figure 10b. Zenker diverticulum in a 54-year-old man with dysphagia and cough. (a) Posteroanterior chest radiograph shows abnormal widening of the superior portion of the mediastinum. An air-fluid level is also seen (arrows). (b) CT scan shows a large retrotracheal diverticulum with an air-fluid level due to retained alimentary content.
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Figure 11a. Achalasia in a 47-year-old woman with chest pain. (a) Close-up view of a posteroanterior chest radiograph shows abnormal widening of the superior part of the mediastinum. An air-fluid level is seen (arrowheads). A calcified paratracheal lymph node is also visible. (b) Lateral radiograph shows anterior displacement and bowing of the trachea caused by the fluid-filled esophagus. An air-fluid level within the retrotracheal space is also apparent (arrowheads), a finding that suggests the diagnosis of achalasia.
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Figure 11b. Achalasia in a 47-year-old woman with chest pain. (a) Close-up view of a posteroanterior chest radiograph shows abnormal widening of the superior part of the mediastinum. An air-fluid level is seen (arrowheads). A calcified paratracheal lymph node is also visible. (b) Lateral radiograph shows anterior displacement and bowing of the trachea caused by the fluid-filled esophagus. An air-fluid level within the retrotracheal space is also apparent (arrowheads), a finding that suggests the diagnosis of achalasia.
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Figure 12a. Esophageal carcinoma in a 68-year-old man with dysphagia and stridor. (a) Lateral chest radiograph shows marked widening of the retrotracheal stripe. Posterior indentation and irregularity of the tracheal air column, produced by neoplastic infiltration of the tracheal wall, are also apparent (arrowheads). (b) CT scan shows marked inhomogeneous thickening of the esophageal wall. Infiltration of the posterior tracheal wall is also seen (arrowhead).
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Figure 12b. Esophageal carcinoma in a 68-year-old man with dysphagia and stridor. (a) Lateral chest radiograph shows marked widening of the retrotracheal stripe. Posterior indentation and irregularity of the tracheal air column, produced by neoplastic infiltration of the tracheal wall, are also apparent (arrowheads). (b) CT scan shows marked inhomogeneous thickening of the esophageal wall. Infiltration of the posterior tracheal wall is also seen (arrowhead).
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Figure 13a. Lymphatic malformation of the superior mediastinum in an asymptomatic 46-year-old woman. (a) Axial T1-weighted MR image shows a large, lobulated lymphatic malformation with intermediate signal intensity. (b) T2-weighted MR image shows a characteristic hyperintense lesion that surrounds but does not displace the trachea and great vessels. The tumor extends toward the anterior soft tissues of the chest wall. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a biopsy specimen shows large, dilated lymphatic channels (*) with walls that contain connective tissue and lymphocytes (arrowheads).
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Figure 13b. Lymphatic malformation of the superior mediastinum in an asymptomatic 46-year-old woman. (a) Axial T1-weighted MR image shows a large, lobulated lymphatic malformation with intermediate signal intensity. (b) T2-weighted MR image shows a characteristic hyperintense lesion that surrounds but does not displace the trachea and great vessels. The tumor extends toward the anterior soft tissues of the chest wall. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a biopsy specimen shows large, dilated lymphatic channels (*) with walls that contain connective tissue and lymphocytes (arrowheads).
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Figure 13c. Lymphatic malformation of the superior mediastinum in an asymptomatic 46-year-old woman. (a) Axial T1-weighted MR image shows a large, lobulated lymphatic malformation with intermediate signal intensity. (b) T2-weighted MR image shows a characteristic hyperintense lesion that surrounds but does not displace the trachea and great vessels. The tumor extends toward the anterior soft tissues of the chest wall. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a biopsy specimen shows large, dilated lymphatic channels (*) with walls that contain connective tissue and lymphocytes (arrowheads).
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Figure 14a. Mediastinal hemangioma in a 67-year-old man. (a) CT scan shows a well-defined heterogeneous mass that lies behind the trachea and displaces the esophagus laterally. A small, rounded calcification (phlebolith) appears within the mass (arrow). (b) Contrast-enhanced CT scan demonstrates the mass with intense central and rimlike peripheral enhancement. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a surgical specimen shows multiple vascular spaces lined by a thin endothelial layer (arrow).
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Figure 14b. Mediastinal hemangioma in a 67-year-old man. (a) CT scan shows a well-defined heterogeneous mass that lies behind the trachea and displaces the esophagus laterally. A small, rounded calcification (phlebolith) appears within the mass (arrow). (b) Contrast-enhanced CT scan demonstrates the mass with intense central and rimlike peripheral enhancement. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a surgical specimen shows multiple vascular spaces lined by a thin endothelial layer (arrow).
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Figure 14c. Mediastinal hemangioma in a 67-year-old man. (a) CT scan shows a well-defined heterogeneous mass that lies behind the trachea and displaces the esophagus laterally. A small, rounded calcification (phlebolith) appears within the mass (arrow). (b) Contrast-enhanced CT scan demonstrates the mass with intense central and rimlike peripheral enhancement. (c) Photomicrograph (original magnification, x40; hematoxylin-eosin stain) of a surgical specimen shows multiple vascular spaces lined by a thin endothelial layer (arrow).
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Figure 15a. Intrathoracic goiter in a 62-year-old woman. (a) Lateral chest radiograph shows a large thyroid mass that fills the retrotracheal space and displaces the trachea anteriorly. (b) CT scan shows a well-defined, homogeneous soft-tissue mass that fills the retrotracheal space and displaces the trachea, esophagus, and supraaortic vessels anteriorly.
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Figure 15b. Intrathoracic goiter in a 62-year-old woman. (a) Lateral chest radiograph shows a large thyroid mass that fills the retrotracheal space and displaces the trachea anteriorly. (b) CT scan shows a well-defined, homogeneous soft-tissue mass that fills the retrotracheal space and displaces the trachea, esophagus, and supraaortic vessels anteriorly.
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Figure 16a. Aortic transection in a 36-year-old man who had sustained a rapid deceleration injury. (a) CT scan shows a mediastinal hematoma that obscures the mediastinal vessels, occupies the retrotracheal space, and displaces the trachea to the right. (b) Contrast-enhanced CT scan shows a pseudoaneurysm (*) medial to the proximal descending thoracic aorta. Bilateral pleural effusions are also seen.
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Figure 16b. Aortic transection in a 36-year-old man who had sustained a rapid deceleration injury. (a) CT scan shows a mediastinal hematoma that obscures the mediastinal vessels, occupies the retrotracheal space, and displaces the trachea to the right. (b) Contrast-enhanced CT scan shows a pseudoaneurysm (*) medial to the proximal descending thoracic aorta. Bilateral pleural effusions are also seen.
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Figure 17. Retropharyngeal infection with mediastinal abscess formation in an 18-year-old man with iatrogenic pharyngeal perforation. CT scan shows widening of the middle mediastinum with a large retrotracheal abscess that fills the retrotracheal space and displaces the trachea and esophagus anteriorly. An air-fluid level within the abscess cavity is also seen.
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Figure 18. Retrotracheal abscess due to fistulized esophageal carcinoma in a 56-year-old man. CT scan shows marked esophageal wall thickening. Air bubbles and a small amount of contrast material within the retrotracheal space due to formation of a fistula (arrow) are also seen.
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Copyright © 2002 by the Radiological Society of North America.
