Urgent and emergent pediatric cardiovascular imaging

Abstract

The need for urgent or emergent cardiovascular imaging in children is rare when compared to adults. Patients may present from the neonatal period up to adolescence, and may require imaging for both traumatic and non-traumatic causes. In children, coronary pathology is rarely the cause of an emergency unlike in adults where it is the main cause. Radiology, including chest radiography and computed tomography in conjunction with echocardiography, often plays the most important role in the acute management of these patients. Magnetic resonance imaging can occasionally be useful and may be suitable in more subacute cases. Radiologists' knowledge of how to manage and interpret these acute conditions including knowing which imaging technique to use is fundamental to appropriate care. In this review, we will concentrate on the most common cardiovascular emergencies in the thoracic region, including thoracic traumatic and non-traumatic emergencies and pulmonary vascular emergencies, as well as acute clinical disorders as a consequence of primary and postoperative congenital heart disease. This review will cover situations where cardiovascular imaging may be acutely needed, and not strictly emergencies only. Imaging recommendations will be discussed according to the different clinical presentations and underlying pathology.

Keywords: Cardiovascular system; Computed tomography; Congenital heart defect; Emergencies; Imaging; Pediatric.

Fig. 1

Contrast-enhanced computed tomography angiography images in a newborn boy with circulatory collapse on day one of life, in whom echocardiography showed poor quality views of the aortic arch. a Sagittal contrast-enhanced image shows a long gap (18.7 mm) between the interrupted aortic arch and the descending aorta. b, c Anteroposterior (b) and sagittal oblique (c) volume rendered images with the ascending and descending aorta and branches in red and pulmonary artery, left pulmonary artery, and open arterial duct (arrow in c) in blue. The open arterial duct secures blood flow to the descending aorta. The left subclavian artery (LSCA) arises from the descending aorta next to the arterial duct. All images (a–c) show a type B interrupted aortic arch occurring just after the right brachiocephalic artery (RBCA) and the left common carotid artery (LCCA)

Fig. 2

A newborn boy with a prenatal diagnosis of pulmonary atresia with intact ventricular septum. The diagnosis was confirmed by echocardiography after birth and prostaglandin infusion was started immediately to assure patency of the arterial duct. a Anteroposterior chest radiograph shows an enlarged heart and small size pulmonary vessels. Two umbilical catheters (one arterial and one venous are positioned in the midline subdiaphragmatically). b Lateral view from cardiac catheterization performed on day 3 of life shows the atretic pulmonary valve (arrows). c, d Treatment with radiofrequency perforation and a snare to open the valve (c) followed by balloon dilatation of the valve (arrow in d). e Lateral angiograph view after dilatation, reveals a successful opening of the pulmonary valve (arrows) and the pulmonary artery. Case courtesy of Dr Janus Freyr Gudnason, Queen Silvia Children’s Hospital, Gothenburg, Sweden

Fig. 3

A 7-month-old girl presenting with acute cardiac failure due to a previous undiagnosed incomplete atrioventricular septal defect with mitral stenosis and a small left ventricle. a Anteroposterior chest radiograph shows an enlarged heart with congestive pulmonary vessels. b Magnetic resonance 2-dimensional (D) steady state free precession image in a 4-chamber view reveals an enlarged right ventricle and right atrium, the atrial primum defect (short arrow) and ventricular septal defect (long arrow). c, d A 4-D phase contrast flow sequence (4-D flow) where the color coding represents blood flow velocity; from low velocity in blue to high velocity in red. c A volume rendered image with traced regions of interest on the different vessels, valves, and shunts showing an enlarged main pulmonary artery and branches. d Multiplanar reconstruction with regions of interest marked on the septal defects (arrows). The 4-D flow sequence enabled visualization of the mitral stenosis (red color) and septal shunts as well as and direct quantification of the shunts with Qp:Qs = 4:1. Ao aorta, LA left atrium, LPA left pulmonary artery, LV left ventricle, MPA main pulmonary artery, RA right atrium, RPA right pulmonary artery, RV right ventricle

Fig. 4

A 2-year-old girl, presenting with acute symptoms with low oxygen saturation 3 weeks after surgical repair to a total cavopulmonary connection. A right and left superior vena cava were anastomosed to the respective pulmonary arteries (bilateral Glenn procedure). Echocardiography did not reveal flow in the right superior vena cava. a–c Contrast-enhanced computed tomography with multiplanar reconstructions in axial (a) coronal (b) and sagittal (c) planes shows a patent left superior vena cava (SVC) with high density contrast in the lumen connected to the left pulmonary artery (arrowhead in a) and confirms the presence of an occluding thrombosis with low density and rim enhancement in the right SVC (arrow in a–c). Ao aorta, CPC cavopulmonary connection to the pulmonary arteries with a conduit from inferior vena cava, LSVC left superior vena cava, LPA left pulmonary artery, RSVC right superior vena cava

Fig. 5

A 9-month-old boy with double outlet right ventricle, surgically repaired with a partial cavopulmonary shunt (Glenn procedure) and extracorporeal membrane oxygenation (ECMO) treatment. The patient was hemodynamically unstable. Contrast-enhanced pulmonary computed tomography angiography with multiplanar reconstructions reformatted images in the sagittal (a) and coronal (b) planes show a linear endoluminal lesion consistent with pulmonary artery dissection (arrows). c Postoperative anteroposterior chest radiograph showing endotracheal tube, ventricular assist cannulae, a pacemaker and pleural drainage catheters, and a stent placed at the Glenn anastomosis (arrow)

Fig. 6

A 9-year-old girl with a heart transplant and a Dacron conduit in the superior vena cava (SVC). The patient presented with acute hypoxemia and pulmonary infiltrates. A contrast-enhanced computed tomography of the thorax was ordered to rule out pulmonary embolism. Bilateral pulmonary consolidations were seen on an axial maximum intensity projection (MIP) image (arrows in a). Angiographic coronal MIP images show occlusive thrombi in the pulmonary arteries of the lower lobes (arrows) in the right lung (b) and the left lung (c). A conduit-associated thrombus was seen on a higher window in coronal multiplanar reconstruction CT image (arrow in d)

Fig. 7

A 16-year-old boy with a peritonsillar abscess, trismus, and hypoxemia. A cervicothoracic contrast-enhanced computed tomography (CT) scan was performed. Sagittal multiplanar reconstruction reformatted images show peritonsillar abscess (arrow in a) and internal jugular vein thrombophlebitis (arrow in b). Axial CT image (c) and axial lung window maximum intensity projection (MIP) reformatted image (d) show multiple bilateral nodules (arrows) consistent with septic emboli, as in Lemierre’s syndrome

Fig. 8

A 13-year-old boy with an anterior mediastinal mass (non-Hodgkin B lymphoma). The patient presented to the emergency department with malaise and dyspnea. A large anterior mediastinal mass was seen on axial contrast-enhanced chest computed tomography (CT) (a). Compression with severe stenosis of the left pulmonary artery was seen (arrows). b Follow-up axial contrast-enhanced CT after chemotherapy 4 weeks later shows significant volume reduction of the mass and resolution of the pulmonary artery compression

Fig. 9

Traumatic non-cardiovascular findings. a Anteroposterior chest radiograph in a 9-year-old boy obtained in the trauma bay demonstrates a mild widening of the upper mediastinum with hazy ill-defined increased paramediastinal opacification. The patient is intubated with a feeding tube in place. External devices are obscuring details. b A 12-year-old girl where an axial contrast-enhanced computed tomography (CT) shows a large mediastinal hematoma (arrow) and consolidations/atelectasis in the dependent aspects of both lungs. c A 10-year-old boy with a contrast-enhanced CT showing a large mediastinal hematoma (asterisk) with active bleed (arrow). Cases courtesy of Dr. David Manson from The Hospital for Sick Children, Toronto, Canada

Fig. 10

A 12-year-old boy with hemopericardium. Axial contrast-enhanced computed tomography of the thorax demonstrates high density pericardial fluid (asterisk) consistent with hemopericardium. Note also a small mediastinal hematoma (arrow) and consolidation/atelectasis of the posterior lungs, more confluent on the left. Courtesy of Dr. David Manson from The Hospital for Sick Children, Toronto, Canada

Fig. 11

An 8-year-old boy with aortic pseudoaneurysm. a Contrast-enhanced computed tomography of the chest demonstrates a pseudoaneurysm in the proximal descending aorta (arrows). Bilateral consolidation/atelectasis is also noted in both lungs posteriorly. b Lateral view of digital subtraction aortic angiography demonstrates a traumatic pseudoaneurysm in the proximal descending aorta. Cases courtesy of Dr. David Manson from The Hospital for Sick Children, Toronto, Canada

Fig. 12

A 16-year-old boy with cardiac displacement due to diaphragmatic rupture. a Anteroposterior chest radiograph with electrodes over the thorax. (b) Coronal plane of a contrast-enhanced computed tomography (CT) with a chest tube in the left thorax and (c) CT in an axial plane. All images demonstrate displacement of the cardiomediastinal structures due to diaphragmatic rupture with herniation of the abdominal contents into the left hemithorax

Fig. 13

A 9-week-old boy with anomalous origin of the left coronary artery from the pulmonary artery who presented in cardiogenic shock. a Anteroposterior chest radiograph shows moderate to severe cardiomegaly with pulmonary edema. An endotracheal tube is near the carina and a nasogastric tube is in the stomach. b-d Coronal (b) and sagittal (c) contrast-enhanced cardiac computed tomography maximum intensity projection and volume rendering technique reconstructions (d), show the left main coronary artery (LMCA) arising from the undersurface of the main pulmonary artery (MPA) (arrows). This patient also has a fine network of collaterals surrounding the LMCA. Note: the dilated left ventricle (LV) due to ischemic cardiomyopathy. Ao aorta, LA left atrium

Fig. 14

A 12 -year-old boy with an anomalous origin of the left coronary artery from the right aortic sinus who suffered a cardiac arrest while playing basketball. a, b Multiplanar oblique contrast-enhanced cardiac computed tomography (CT) reconstructions show the anomalous origin of the left main coronary artery from the right aortic sinus arising at an acute angulation with an interarterial course. There is a very thin poorly opacified intramural segment (arrows) that crosses across the right-left aortic commissure. c Coronal cardiac CT reconstruction shows the interarterial portion in cross section (arrow), which is slit-like with loss of pericoronary fat, typical signs of an intramural segment

Fig. 15

An 11-year-old boy with a myocardial infarction who presented in hypertensive crisis with cardiac dysfunction, initially suspected to be an infectious or inflammatory myocarditis. a Short-axis magnetic resonance 3-dimensional high-resolution late gadolinium enhancement reconstructions show irregular wall thickening and enhancement of the right coronary artery (arrow), suggestive of a coronary vasculitis. b There is also transmural late gadolinium enhancement in the left anterior descending (LAD) territory (arrowheads) with significant central subendocardial microvascular obstruction (short arrow), consistent with a myocardial infarction. The LAD itself was not able to be well visualized (not shown). c Subsequent right anterior oblique cardiac catheterization projection shows a wire bypassing a proximal LAD occlusion

Fig. 16

A 4-year-old boy with Loeys-Dietz syndrome complicated by aortic dissection. a Contrast-enhanced computed tomography (CT) parasagittal-oblique volume rendering projection shows a dilated and tortuous aorta, along with severe tortuosity of the head and neck vessels, especially of the vertebral arteries. b, c Axial (b) and coronal (c) CT images 4 years later show an aortic dissection flap (arrows) extending from the ascending aorta to infrarenal abdominal aorta, consistent with a type-A dissection