Vascular rings and slings

Computed

tomography in the evaluation of vascular rings and slings. Development of the aorta and branch vessels. a Illustration showing the schematic development of the aorta and arch branch vessels from six pairs of aortic arches. Please note that the six arches are never seen together in the foetus, since they develop and regress in a craniocaudal direction. Also, the fifth arch is not present in most foetuses. b Illustration showing the fully developed normal left aortic arch and branch vessels, with corresponding colour codes. a The left arch between the left common carotid and left subclavian (red) is derived from the left fourth arch (red). The ventral aorta (purple) forms the ascending aorta and the right brachiocephalic trunk while the dorsal aorta (green) forms the descending thoracic aorta. The left subclavian artery is derived from the left seventh intersegmental artery (brown), while the right subclavian artery is derived proximally from the right fourth arch (red), in the mid portion from the right dorsal aorta (green) and the distal portion from the right seventh intersegmental artery (brown). The aortic root and main pulmonary artery are derived from division of the truncus arteriosus (pink). The ductus arteriosus (blue) is formed from the dorsal portion of the left sixth arch, while the right and left pulmonary arteries are derived from ventral portions of the right and left sixth arches (yellow) respectively. Common carotid arteries are derived from the third arches (orange), while internal carotid arteries are formed from the third arches (orange) and the dorsal aorta (green). External carotid arteries are derived from the third arch branches (black)

Imaging of

congenital lung diseases presenting in the adulthood: a pictorial review. A 71-year-old asymptomatic male with pulmonary artery sling. Contrast-enhanced axial CT image (a) and 3D cinematic volume-rendered image (b) depict the aberrant left pulmonary artery arising from the right pulmonary artery and crossing to the left hemithorax

Computed

tomography in the evaluation of vascular rings and slings. Double aortic arch. a Illustration showing the appearances of a double aortic arch, with a dominant right arch. The right arch gives off the right subclavian (RSC) and right common carotid (RCC) branches, while the left arch gives off the left subclavian (LSC) and left common carotid (LCC) arteries. Both the trachea and oesophagus are completely encircled and compressed by the vascular ring. b Axial CT scan shows the four-vessel sign. The first branch is the right subclavian (RSC) artery, the second is the right common carotid artery (RCC), the third is the left common carotid (LCC) artery and the fourth is the left subclavian (LSC) artery. c Axial MIP image shows bilateral aortic arches encircling the trachea and oesophagus. The right aortic arch (arrow) is larger than the left aortic arch (arrowhead). d Coronal reconstructed CT image at the level of the trachea shows a larger right arch (long arrow) and a smaller left arch (smaller arrow) encircling the trachea (asterisk). e Coronal MIP CT image at the level of the trachea shows similar-sized double arches in another patient (arrows). f 3D volume-rendered image exquisitely demonstrates the double aortic arch, with a dominant right arch (arrow) and a smaller left arch (arrowhead), both of which join the descending thoracic aorta (*), which is located on the left. g 3D volume-rendered image in another patient (same patient as e) demonstrates the double aortic arch, with similar sizes of the right arch (arrow) and the left arch (arrowhead), both of which join the descending thoracic aorta (*), which is located on the left. h Coronal volume-rendered image of the airway shows severe narrowing of the airway (arrow) by the double aortic arch

Computed

tomography in the evaluation of vascular rings and slings. Double aortic arch with an atretic left arch. a and b Axial CT scan images show bilateral aortic arches. The right aortic arch is dominant (arrow). The left aortic arch is atretic (arrowhead). c 3D volume-rendered image demonstrates the double aortic arch. The dominant right aortic arch (arrow) gives off the right subclavian and right common carotid branches, while the left atretic aortic arch gives off the left common carotid and left subclavian arteries proximal to the atretic region (arrowhead). Only the right aortic arch joins the descending aorta (*). d Virtual bronchoscopy demonstrates severe narrowing of the airway by the double aortic arch with atretic left arch

Computed

tomography in the evaluation of vascular rings and slings. Post-surgical changes of double aortic arch repair. Postoperative sagittal 3D volume-rendered image demonstrates separation of the nondominant left aortic arch (arrow) from the descending aorta and surgical interruption of the complete vascular ring

Computed

tomography in the evaluation of vascular rings and slings. Right aortic arch with Kommerell’s diverticulum. a Illustration of a right aortic arch (black arrow) with a prominent Kommerell diverticulum (white arrow) in the proximal descending thoracic aorta (*), compressing the oesophagus (E). b Axial CT scan shows a right aortic arch (arrow) with a large Kommerell diverticulum (arrowhead) compressing the posterior oesophagus. c Coronal MIP image demonstrates a right aortic arch (arrow) and prominent Kommerell diverticulum (arrowhead) in the proximal descending thoracic aorta (*). d Reconstructed 3D volume-rendered image exquisitely demonstrates the right aortic arch (arrow) with a large Kommerell diverticulum (*) giving off the retroesophageal aberrant left subclavian artery (arrowhead). e Coronal CT image shows airway narrowing (arrow) caused by the vascular ring

Computed

tomography in the evaluation of vascular rings and slings. Right arch with mirror image branching and a left ductus arteriosus. a Schematic illustration of a right aortic arch with mirror image branching shows a left brachiocephalic artery giving a branch to the left common carotid and left subclavian arteries. b Coronal MIP image and c Volume-rendered 3D image in a patient with a right aortic arch (A) and mirror image branching pattern show a patent ductus arteriosus (white arrow) extending from the left brachiocephalic (L BC) artery to the left pulmonary artery (L PA) forming a ring

Computed

tomography in the evaluation of vascular rings and slings. Circumflex right aortic arch. a Axial CT image shows a right aortic arch (arrow), which extends behind the oesophagus to reach the side. b Axial CT image at a lower level shows the arch has now reached the right (arrow) and continues as the descending aorta on the left. c Axial CT image at a lower level shows the left descending thoracic aorta (arrow)

Computed

tomography in the evaluation of vascular rings and slings. Left aortic arch with an aberrant right subclavian artery. a Illustration showing the appearances of a left aortic arch (arrow) with an aberrant right subclavian (RSC) artery. The first branch from the arch is the right common carotid (RCC) artery, followed by the left common carotid (LCC) artery and then the left subclavian (LSC) artery. The right subclavian (RSC) artery has an aberrant origin as the last branch originating from the proximal descending thoracic aorta and has a retroesophageal (E) course to reach the right side. b Axial CT scan shows an aberrant right subclavian artery (arrow) originating from the proximal descending thoracic aorta and has a retroesophageal course to reach the right. Posterior indentation and compression of oesophagus are seen. c Coronal MIP image demonstrates the aberrant right subclavian artery (arrow) originating from the proximal descending aorta and reaching the right. Normal left subclavian artery (arrowhead) is also seen. d Coronal reconstructed 3D volume-rendered image shows the aberrant right subclavian artery (arrow) originating from the proximal descending thoracic aorta (*) and coursing to the right behind the oesophagus, which is compressed

Computed

tomography in the evaluation of vascular rings and slings. Aneurysm of an aberrant right subclavian artery. a Axial CT scan shows a large aneurysm with partial thrombosis (arrow) at the origin of an aberrant right subclavian artery in a patient with a left aortic arch. b Coronal CT reformatted image in the same patient shows the partially thrombosed aneurysm (arrow) at the origin of an aberrant right subclavian artery

Computed

tomography in the evaluation of vascular rings and slings. Anomalous innominate artery. a Schematic illustration shows an anomalous course of an innominate artery originating more posterior and to the left than normal, coursing to the right anterior to the trachea. b Axial CT image shows a dilated innominate artery (arrow) compressing the anterior trachea. c Sagittal reformatted MinIP (minimal intensity projection) image shows indentation of the anterior aspect of the trachea (arrowhead) by a dilated anomalous innominate artery (black arrow)

Computed

tomography in the evaluation of vascular rings and slings. Pulmonary sling. a Illustration showing an anomalous left pulmonary artery (LPA), which originates from the right pulmonary artery (R PA) and then crosses between the trachea (T) and oesophagus (E) to reach the left. b Axial CT scan shows an anomalous left pulmonary artery (L PA), which originates from the right pulmonary artery (R PA) and then crosses between the trachea and oesophagus (white arrow) to reach the left. c Coronal MinIP image of the airway shows a bridging bronchus (BB) that originates from the left main bronchus (LMB) and crosses the mediastinum to reach the side where it supplies the right middle and lower lobe. The right upper lobe (RUL) bronchus arises from the trachea