Common and uncommon vascular rings and slings: a multi-modality review

Double aortic arch: a comparison of fetal cardiovascular magnetic resonance, postnatal computed tomography and surgical findings

BACKGROUND

In double aortic arch (DAA), one of the arches can demonstrate atretic portions postnatally, leading to diagnostic uncertainty due to overlap with isolated right aortic arch (RAA) variants. The main objective of this study is to demonstrate the morphological evolution of different DAA phenotypes from prenatal to postnatal life using three-dimensional (3D) fetal cardiac magnetic resonance (CMR) imaging and postnatal computed tomography (CT)/CMR imaging.

METHODS

Three-dimensional fetal CMR was undertaken in fetuses with suspected DAA over a 6-year period (January 2016-January 2022). All cases with surgical confirmation of DAA were retrospectively studied and morphology on fetal CMR was compared to postnatal CT/CMR and surgical findings.

RESULTS

Thirty-four fetuses with surgically confirmed DAA underwent fetal CMR. The RAA was dominant in 32/34 (94%). Postnatal CT/CMR was undertaken at a median age of 3.3 months (interquartile range 2.0-3.9) demonstrating DAA with patency of both arches in 10/34 (29%), with 7 showing signs of coarctation of the left aortic arch (LAA). The LAA isthmus was not present on CT/CMR in 22/34 (65%), and the transverse arch between left carotid and left subclavian artery was not present in 2 cases.

CONCLUSION

Fetal CMR provides novel insights into perinatal evolution of DAA. The smaller LAA can develop coarctation or atresia related to postnatal constriction of the arterial duct, making diagnosis of DAA challenging with contrast-enhanced CT/CMR. This highlights the potentially important role for prenatal 3D vascular imaging and might improve the interpretation of postnatal imaging.

Can Echocardiography Aid in Diagnosing Vascular Rings?

Even though cardiac computed tomography and magnetic resonance imaging are the gold standard for evaluating the aortic arch in the context of vascular rings in children, echocardiography is usually the first-line modality. The echocardiographic evaluation of the aortic arch in the context of vascular rings in children has received little attention. This article details the step-by-step echocardiographic assessment of the aortic arch in vascular ring patients.

3D CT cinematic rendering of pediatric thoracic vascular anomalies

Thoracic vascular anomalies in the pediatric population are a heterogeneous group of diseases, with varied clinical presentations and imaging findings. High-resolution computed tomography is widely available and has become a standard part of the workup of these patients, often with three dimensional images. Cinematic rendering is a novel 3D visualization technique that utilizes a new, complex global lighting model to create photorealistic images with enhanced anatomic detail. The purpose of this pictorial review is to highlight the advantages of cinematic rendering compared to standard 2D computed tomography and traditional volume-rendered 3D images in the evaluation of thoracic vascular anomalies. Although cinematic rendering remains a new visualization technique under continued study, the improved anatomic detail and photorealistic quality of these images may be advantageous for surgical planning in cases of complex vascular abnormalities. Cinematic rendering may also help improve communication among clinicians, trainees, and patients and their families.

Aortic Arch Variants and Anomalies: Embryology, Imaging Findings, and Clinical Considerations

There is a wide spectrum of congenital anomalies or variations of the aortic arch, ranging from non-symptomatic variations that are mostly detected incidentally to clinically symptomatic variations that cause severe respiratory distress or esophageal compression. Some of these may be accompanied by other congenital heart diseases or chromosomal anomalies. The widespread use of multidetector computed tomography (CT) in clinical practice has resulted in incidental detection of several variations of the aortic arch in adults. Thus, radiologists and clinicians should be aware of the classification of aortic arch anomalies and carefully look for imaging features associated with a high risk of clinical symptoms. Understanding the embryological development of the aortic arch aids in the classification of various subtypes of aortic arch anomalies and variants. For accurate diagnosis and precise evaluation of aortic arch anomalies, cross-sectional imaging modalities, such as multidetector CT or magnetic resonance imaging, play an important role by providing three-dimensional reconstructed images. In this review, we describe the embryological development of the thoracic aorta and discuss variations and anomalies of the aortic arch along with their clinical implications.

Right aortic arch with brachio-bicephalic trunk mimicking an incomplete double aortic arch with distal left arch atresia

We report a case of a 6-month-old girl with double outlet right ventricle where a right aortic arch with an abnormally posterior brachio-bicephalic trunk on the left side closely resembled an incomplete double-aortic-arch with distal left arch atresia on computed tomography (CT) angiography. The case highlights the role of preoperative CT angiography in demonstrating aortic arch and arch vessel anatomy in patients with complex congenital heart diseases.

Pulmonary sling in a patient with common arterial trunk

We report a rare association of common arterial trunk with left pulmonary artery sling and highlight the importance of cross-sectional imaging in complex congenital cardiac lesions. The patient was antenatally diagnosed with common arterial trunk and underwent surgical repair in the neonatal period. At the age of 20 months, the patient presented with respiratory symptoms and increased right ventricular pressure. Multislice computed tomography demonstrated a pulmonary sling with compression of the distal trachea. Surgical correction of the pulmonary sling and change of the right ventricular to pulmonary artery conduit to a bigger size was performed.

Fetal Vascular Rings and Pulmonary Slings: Strategies for Two- and Three-Dimensional Echocardiographic Diagnosis

Fetal aortic arch anomalies and pulmonary slings can be difficult to accurately diagnose but have important clinical implications related to vascular rings, congenital heart disease, and chromosomal anomalies. In this article, the authors briefly review the embryology and development of the fetal arch to facilitate understanding of its diverse variants. Two-dimensional echocardiographic characteristics are summarized for each type of these malformations to propose a strategy for fetal diagnosis. The added benefits of three-dimensional echocardiography with spatiotemporal image correlation are also shown. Finally, the authors propose a strategy for volume acquisition and postanalysis to spur postanalysis clinical use of this technology.

Atretic Double Aortic Arch: Imaging Appearance of a Rare Anomaly and Differentiation From Its Mimics

A double aortic arch (DAA) with atresia is an uncommon cause of a symptomatic vascular ring resulting in trachea-esophageal compression. An atretic double aortic arch can resemble the right aortic arch with a mirror image branching pattern or the right arch with an aberrant left subclavian artery depending upon the level of atresia. The double aortic arch with atresia is difficult to detect on pre-surgical computed tomography angiography or magnetic resonance angiography due to a lack of contrast in the obliterated arch segment. Differentiation of a double arch with atresia from the right aortic arch is vital as an atretic double arch is a form of the complete vascular ring while the right aortic arch may or may not be symptomatic. Knowledge of some key imaging features can help distinguish these entities. In this case report, we discuss an uncommon case of a double aortic arch with atresia between the left common carotid and left subclavian artery. We also describe its close mimics, their embryological basis, and ways to differentiate it from the right aortic arch.

Prenatal diagnosis and clinical implications of an apparently isolated right aortic arch

OBJECTIVE

To define the associations of a prenatally diagnosed, apparently isolated right aortic arch (RAA) with chromosomal or genetic abnormalities and tracheal compression.

METHODS

This was a retrospective study of apparently isolated RAA assessed by fetal cardiologists and fetal medicine specialists at Kings College Hospital, London between 2000 and 2017.

RESULTS

The search identified 138 cases of apparently isolated RAA. Invasive testing was performed in 75, and chromosomal or genetic anomalies were identified in 16 (22%), and the most common was 22q11 microdeletion. An aberrant left subclavian artery was seen in 51% of cases. Symptoms of a vascular ring were present in 24 of 97 (25%) children who were reviewed after birth. Bronchoscopy was performed in 33 children, and significant tracheal compression was diagnosed in 28, including 18 of 19 symptomatic and 10 of 14 asymptomatic children.

CONCLUSIONS

An apparently isolated RAA is associated with a high incidence of chromosomal or genetic abnormalities and a high incidence of tracheal compression in symptomatic and asymptomatic patients. Prenatal counselling for genetic associations and postnatal airway assessment in the context of the vascular anatomy is recommended.

Methodology of echocardiographic analysis of morphological variations of the aortic arch and its branches in children - own experience

We wish to share our experience in echocardiographic assessment of the course of the aortic arch, illustrating it with multiple examples of the majority of possible variants. The course of the aortic arch and its branches may be visualized using high parasternal and suprasternal views in sagittal and transverse planes. It is hardly ever possible to visualize the entire aortic arch on a single ultrasonographic section, particularly in the case of pathological variations. Echocardiography should be performed in a dynamic mode, as in the case of CT angiography or magnetic resonance, by gradually moving the ultrasound beam and following the position of subsequent aortic segments and branches on the screen. Due to disturbances in ultrasound propagation caused by air-containing tissues, such as the trachea, bronchi and lungs as well as bones (sternum and ribs), each evaluation of the entire arch requires the use of a higher number of echocardiographic views. The presented data show that echocardiographic detection of the main details of aortic arch anomalies is possible in practically all cases. In the case of patients considered for surgical treatment, all unresolved issues should be clarified with CT angiography or MRI, enabling 3 dimensional reconstruction of vessels and other thoracic structures. Knowledge of the main elements of an abnormal arch is crucial for proper planning of this type of examination; therefore the diagnostic process should be always initiated with echocardiography. Echocardiography is often sufficient to answer all clinical questions and finalize the diagnostic process.

We wish to share our experience in echocardiographic assessment of the course of the aortic arch, illustrating it with multiple examples of the majority of possible variants. The course of the aortic arch and its branches may be visualized using high parasternal and suprasternal views in sagittal and transverse planes. It is hardly ever possible to visualize the entire aortic arch on a single ultrasonographic section, particularly in the case of pathological variations. Echocardiography should be performed in a dynamic mode, as in the case of CT angiography or magnetic resonance, by gradually moving the ultrasound beam and following the position of subsequent aortic segments and branches on the screen. Due to disturbances in ultrasound propagation caused by air-containing tissues, such as the trachea, bronchi and lungs as well as bones (sternum and ribs), each evaluation of the entire arch requires the use of a higher number of echocardiographic views. The presented data show that echocardiographic detection of the main details of aortic arch anomalies is possible in practically all cases. In the case of patients considered for surgical treatment, all unresolved issues should be clarified with CT angiography or MRI, enabling 3 dimensional reconstruction of vessels and other thoracic structures. Knowledge of the main elements of an abnormal arch is crucial for proper planning of this type of examination; therefore the diagnostic process should be always initiated with echocardiography. Echocardiography is often sufficient to answer all clinical questions and finalize the diagnostic process.

Non-invasive diagnosis of aortic arch anomalies in children - 15 years of own experience

Aim

To summarize our experience in echocardiographic diagnosis of aortic arch anomalies in pediatric patients.

Materials and methods

A retrospective assessment of echocardiographic findings in Echo-Lab patients of the Pediatric Cardiac Surgery Department, who were diagnosed with an anomalous aortic arch between 2003 and 2018.

Results

The diagnosis of an abnormal course of the aortic arch and/or its branches was established in 115 children aged between 4 days and 17 years. The following types of anomalies were detected: left aortic arch with aberrant right subclavian artery in 42 patients; right aortic arch with left brachiocephalic trunk in 14 patients; right aortic arch, aberrant left subclavian artery in 36 patients; double aortic arch in 14 patients; and other, more complex types in 9 patients. The main elements of defects were correctly identified by echo in all cases. We decided to additionally perform computed tomography angiography in 32 patients to clarify all details necessary to qualify patients for surgery and establish the surgical plan.

Conclusions

1. Echocardiography strictly following the pre-determined protocol has 100% sensitivity in the detection of basic elements of aortic arch anomaly and is a perfect tool for diagnostic process initiation. 2. Since it is not possible to visualize all anatomic details, the qualification for surgery should by based on computed tomography angiography or cardiac magnetic resonance imaging, which precisely visualize both abnormal vessels and compressed structures.

Congenital anomalies of the aortic arch

Congenital anomalies of the aortic arch include diverse subgroups of malformations that may be clinically silent or may present with severe respiratory or esophageal symptoms especially when associated with complete vascular rings. These anomalies may be isolated or may be associated with other congenital heart diseases. Volume rendered computed tomography (CT) and magnetic resonance angiography (MRA) help in preoperative surgical planning by providing information about the complex relationship of aortic arch and its branches to the trachea and esophagus. Three dimensional capabilities of both computed tomography angiography (CTA) and MRA are helpful in determining evidence of tracheal or esophageal compression or other high-risk features in patients with a complete vascular ring.

[Specific characteristics of chest X‑ray in childhood : Basics for radiologists]

The radiographic technique of pediatric chest X‑rays is substantially different from that in adults. In nearly all cases ap/pa X‑rays are sufficient and lateral radiographs are rarely needed. In the first years of life the thymus may overshadow the heart, the great vessels and the lung hila. The most important anatomical structures essential for diagnosing pathological findings of the lungs and mediastinum are the trachea with the bifurcation and the main bronchi with the adjacent great vessels. For the assessment of distended lungs and intrathoracic consolidations, fundamental knowledge of the anatomy in childhood and malformations which can involve the airways, the lungs, the heart, as well as systemic and pulmonary vessels are indispensable. Diseases of the pleura and the chest wall should always be investigated by ultrasound. Malignant disorders are rare in children, except for lymphomas. Optimized computed tomography (CT) and/or magnetic resonance imaging (MRI) are crucial in the diagnostic workflow of complex congenital heart diseases, complex lung and airway malformations, pulmonary complications in cystic fibrosis and the diagnostics of all tumors in order to make the right treatment decisions.

Diagnostic Accuracy of Three-dimensional Turbo Field Echo Magnetic Resonance Imaging Sequence in Pediatric Tracheobronchial Anomalies with Congenital Heart Disease

Tracheobronchial anomalies are common in congenital heart disease (CHD), including tracheobronchial stenosis, tracheal bronchus, cardiac bronchus, and bronchial isomerism, which can cause varying degrees of respiratory illness. It is necessary to assess tracheobronchial anomalies and make a preoperative airway evaluation. Multi-slice computed tomography (MSCT) and cardiac magnetic resonance imaging (MRI) are the most effective noninvasive modalities for the diagnosis of CHD and the associated tracheobronchial anomalies. However, MSCT remains an ionizing procedure despite using low dose protocols. The aim of this study was to evaluate diagnostic accuracy of tracheobronchial anomalies in patients with CHD using three-dimensional turbo field echo(3D-TFE) magnetic resonance imaging sequence for preoperative airway evaluation. The results indicated that 3D-TFE provided better image quality as compared to that of 3D-balanced turbo field echo (3D-bTFE), and it can clearly demonstrated the tracheobronchial tree and tracheobronchial anomalies in CHD. This study confirms the clinical value of 3D-TFE in diagnosing tracheobronchial anomalies and supply helpful tracheobronchial information for preoperative strategies and postoperative follow-up.

Multimodality imaging of pediatric airways disease: indication and technique

Congenital and acquired airway anomalies represent a relatively common albeit diagnostic and therapeutic challenge, even for the most skilled operators in dedicated centers. Airway malformations encompass a wide spectrum of pathologies involving the larynx, trachea and bronchi, esophagus, mediastinal vessels. These developmental lesions are often isolated but the association of two or more anomalies is not infrequent. From the traditional chest X-ray to the newest applications of Optical Coherence Tomography, non- or mini-invasive diagnostic techniques represent useful tools to integrate invasive procedures. Comprehensive knowledge of the characteristics of each diagnostic test is mandatory for its useful application. The aim of our paper is to analyze the clinical indications for Imaging the Airway disease in pediatric population, and describe the diagnostic techniques. Only by a close interaction between all the operators involved in diagnosis and treatment of pediatric airway, as it happens in Multidisciplinary Airway Team, the non- or mini-invasive imaging is effective.

Identification and management of fetal isolated right-sided aortic arch in an unselected population

OBJECTIVE

Inclusion of the three vessels and trachea view in the routine assessment of the fetal heart at the 18-20-week morphology scan improves recognition of a right-sided aortic arch (RAA). We report our experience of RAA diagnosed in an unselected population of pregnant women attending for a routine morphology scan.

METHODS

The obstetric imaging databases of two ultrasound centers were reviewed retrospectively to identify all routine fetal morphology scans performed at 18-22 weeks' gestation between January 2011 and December 2014. A review of postnatal charts was conducted to ascertain findings at birth, neonatal complications and the anatomical findings at any neonatal echocardiographic or surgical procedure. Parents of older infants were contacted by phone to assess their wellbeing and identify any respiratory or feeding difficulties.

RESULTS

In the 48-month study period, 43 083 routine anomaly scans were performed. Twenty-three cases of isolated RAA were identified, a prevalence of 0.05%. Nineteen (83%) cases of isolated RAA had a left-sided arterial duct and four (17%) had a right-sided duct. Postnatal follow-up data were obtained in all cases. The prevalence of a symptomatic vascular ring due to a double aortic arch was 13% (3/23). One (4%) case was diagnosed with DiGeorge syndrome.

CONCLUSIONS

RAA can be identified easily on a routine fetal anomaly scan, however the prevalence of RAA is low in an unselected population. Antenatally diagnosed cases should be referred for detailed fetal echocardiography and the patient should be made aware of the association with DiGeorge syndrome and the symptoms associated with a vascular ring. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Useful signs for the assessment of vascular rings on cross-sectional imaging

Vascular rings can be challenging to diagnose because they can contain atretic portions not detectable with current imaging modalities. In these cases, where the compressed airway and esophagus are not encircled by patent, opacified vessels, there are useful secondary signs that should be considered and should raise suspicion for the presence of a vascular ring. These signs include a double aortic arch, the four-vessel sign, the distorted subclavian artery sign, a diverticulum of Kommerell, a ductal diverticulum contralateral to the aortic arch, and a descending aorta contralateral to the arch or circumflex aorta. If none of these findings is present, a ring can be excluded with confidence.

Newborn respiratory distress: airway abnormalities

Respiratory distress is a common symptom in the newborn. Surfactant deficiency in the preterm infant and meconium aspiration and transient tachypnea in the term newborn are among the most common causes of respiratory distress, but primary airway abnormalities can also present with respiratory distress in the newborn. Delay in diagnosis of airway abnormality can be life threatening. Radiologists are among the first to be consulted in the evaluation of a neonate with respiratory distress, and knowledge of the spectrum of airway anomalies is essential for making the correct diagnosis. This article describes airway abnormalities that can present as respiratory distress in a neonate.

Congenital vascular rings: a clinical challenge for the pediatrician

Vascular rings are congenital anomalies that lead to variable degrees of respiratory problems or feeding difficulties by forming a complete or partial ring compressing the trachea, the bronchi, and the esophagus. The clinical diagnosis of vascular rings is often challenging for the pediatrician because the clinical manifestations are heterogeneous and nonspecific. Symptoms can vary from wheezing, stridor, dyspnea, and/or dysphagia to life-threatening conditions; however, they may not be present. The aim of this study is to review the recent literature on this subject and describe new developments in diagnostics and imaging.

Rings and slings revisited

Vascular rings and pulmonary artery slings are rare congenital anomalies that often present with symptoms of tracheal and esophageal compression. These can involve the aortic arch branches and pulmonary arteries, respectively. This review illustrates the current role of MR imaging, highlights its advantages, and provides insight into the diagnosis of these anomalies by describing the embryology and characteristic imaging features of these lesions.

Congenital lung malformations: radiological findings and clues for differential diagnosis

Congenital lung malformations encompass a wide spectrum of conditions with a broadly varying clinical presentation. They are often a source of morbidity in infants and children. Their management depends on the type of malformation and its clinical presentation. Usually, the diagnosis requires an imaging evaluation. Classifications of bronchopulmonary malformations have undergone significant revision in recent years and several theories have attempted to explain their confusing pathogenesis. There are considerable degrees of overlapping and hybrid conditions are common, with interrelated malformations showing various radiologic and pathologic features. Attending to the pathophysiological mechanisms and structures involved, lung malformations can be divided into three categories: bronchopulmonary anomalies, combined lung and vascular abnormalities, and vascular anomalies. The purpose of this article is to review the current imaging techniques for evaluating lung malformations in pediatric patients and their characteristic imaging findings. Moreover, this review discusses a useful classification and offers some clues to facilitate the differential diagnosis.

Are contrast swallows a relevant investigation for paediatric stridor?

The contrast swallow has traditionally been used in the investigation of paediatric stridor with the aim of identifying pathology such as vascular rings and confirming the presence of gastro-oesophageal reflux. Currently, a laryngotracheobronchoscopy (LTB) is the gold standard investigation for stridor and frequently, a child is commenced on antireflux medications based on clinical history. We seek to identify whether a contrast swallow has a valuable and cost effective role in the investigation of paediatric stridor. This was a retrospective audit study. All the children who underwent a contrast swallow as part of the investigation for stridor were identified from 2008 to 2011. All requests were made by clinicians from the ENT department at Birmingham Children's Hospital. All patient demographics and radiological reports were reviewed. The final patient list was cross referenced with theatre records to identify those that underwent a LTB The cost of the contrast swallow was identified by the contracting department at Birmingham Children's Hospital. A total of 117 contrast swallows were requested during the study period. The age range was 1 week to 50 months with an average patient age of 6 months. 45/117 (38 %) of contrast swallows identified pathology. 33/45 (73 %) demonstrated reflux. Only 12/117 (10 %) of all cases suggested pathology other than reflux. A total of 51 patients underwent LTB. 22/51 (43 %) had a subsequent contrast swallow. Since the average cost per contrast swallow in the outpatient setting was £ 77, and only 9 cases demonstrated significant unexpected pathology, 108 children had a contrast swallow that did not significantly alter the management of their stridor. 9 cases were identified in which the contrast study results altered the management of the child. An estimated £ 8,000 were spent on investigations that made no impact on the subsequent management of the child. Contrast swallows requested for the investigation of paediatric stridor identified 33 cases of gastro-oesophageal reflux and 12 cases of alternative pathology. Among those children with radiological evidence of reflux, 70 % (23/33) had already been commenced on antireflux medication based on their clinical symptoms. Only 8 % of findings from a contrast swallow investigation resulted in a change to the management of the stridulous child. The authors suggest that it is more cost effective to reserve requests for a contrast swallow until the diagnostic LTB is performed. This strategy will not only reduce exposure to ionising radiation in a significant number of children, but also identifies airway pathology more effectively and ensures that contrast swallows are used as an appropriate adjunctive diagnostic investigation.

Prevalence of ligamentum arteriosum calcification on multi-section spiral CT and digital radiography

To investigate the prevalence of ligamentum arteriosum calcification (LAC) on multi-section spiral CT and digital radiography. Five hundred and eight children and 232 adults who performed multi-section chest CT were included in this study and were divided into nine age groups: A (0-5 years), B (6-10 years), C (11-15 years), D (16-20 years), E (21-30 years), F (31-40 years), G (41-50 years), H (51-60 years), and I (61-70 years). Two radiologists assessed the presence of LAC on axial and coronal CT images, defined as focal calcific density on both or on one plane with attenuation >100 Hounsfield unit. The prevalence of LAC on CT was compared between children and adults, and between unenhanced and enhanced CT in children. The prevalence of LAC on digital radiography was evaluated in 476 children. The prevalence of definite LAC on unenhanced multi-section CT was significantly higher in children (37.8 %) than in adults (11.2 %) (P < 0.001), with prevalences in groups: A through I of 35.8, 48.7, 35.1, 28.6, 25.0, 10.2, 15.5, 7.8, and 5.6 %, respectively. The prevalences of indeterminate LAC in age groups A-I on unenhanced multi-section CT were 4.5, 12.8, 8.1, 19.0, 0.0, 0.0, 0.0, 2.0, and 1.9 %. In children, the prevalence of LAC was significantly higher on unenhanced than on enhanced CT (37.8 vs. 16.4 %, P < 0.001). The prevalence of LAC on digital radiography was 3.6 % in children. LAC is frequently observed in children and adults on multi-section spiral CT, more frequently than previously reported. Compared with that on multi-section spiral CT, the prevalence of LAC on digital radiography is substantially low.