Heart and Great Vessels: The Great Vessels

10.1055/b-0034-87858

Heart and Great Vessels: The Great Vessels

In young children, the great vessels, on conventional radio-graphs, are or can be obscured by the shadow of the thymus. As the thymus diminishes in size, the great vessels become more and more visible.

Imaging of the great vessels will mostly be done using CT and/or MRI. The use of diagnostic angiography should be considered to be obsolete.

**Table 1.82 The great vessels, normal appearance**
Diagnosis	Findings	Comments
Normal aorta and pulmonary artery	Left-sided aorta.	In young children, the aorta is not always visible due to overlying thymic tissue. The diameter of the aorta is influenced by respiration. In expiration, the aorta can enlarge and mimic a pathologic situation.
Normal superior vena cava	In children, the outline can be obscured by the thymus.

**Table 1.83 The great vessels, pathologic changes of the aorta (size, shape, position)**
Diagnosis	Findings	Comments
Dilatation (aneurysm) of the ascending aorta	Dilated right-sided aorta shadow. Displacement of the superior border leads to an aortic knuckle.	The ascending aorta should not form a distinct shadow (i.e., be border-forming) below the age of 10 y. Causes include congenital valvular aortic stenosis, aortic insufficiency, truncus arteriosus, and aneurysms.
PDA Fig. 1.215a, b Fig. 1.216a, b	Dilatation of the ascending aorta and main pulmonary artery.	Endovascular treatment with plugs (e.g., Amplatzer device) is a widely used technique. The device is visible on conventional radiographs. Dislocation, into the pulmonary circulation, may occur. Other techniques are endovascular coiling or transthoracic clipping.
Narrow vascular pedicle in transposition of the great vessels Fig. 1.205, p. 118	A result of the ascending aorta projecting over the pulmonary trunk. Seen in transposition of the great vessels.
Right-sided aortic arch (high right aorta) Fig. 1.217	Right aortic arch in the right superior mediastinum.	Can be seen as a solitary anomaly. However, mostly seen in combination with tetralogy of Fallot (25%) or truncus arteriosus (35%).
Diagnosis	Findings	Comments
Coarctation of the aorta Fig. 1.218a, b Fig. 1.219	Slight predominance of the left-sided aortic arch. On the conventional radiograph a “figure of 3” can be seen. Hypertrophy of the intercostal vessels can lead to rib-notching. If present, the positive predictive value is 50%
Aortic aneurysm	In the majority of cases, dilatation of the ascending aorta.	Rare in children, mostly the result of trauma or infection.
Aneurysmal dilatation of the ductus arteriosus Fig. 1.220	Visible on cardiac US or MRI. Extremely rare.	May calcify later in life.

**Fig. 1.215a, b PDA.** (a) A 14-year-old boy with a coil in the Botallian duct (see insert). (b) A 2-week-old boy after clipping of the Botallian duct. Note the dislocated rib as a result of the left thoracotomy (arrow).

**Fig. 1.216a, b PDA.** (a) A 2-year-old girl after endovascular treatment for a persistent Botallian duct using an Amplatzer device (see insert). (b) Posteroanterior radiograph of the same child as in (a) shows dislocation of the Amplatzer plug into to the pulmonary artery (arrow).

**Fig. 1.217 Right-sided aortic** arch in a 12-year-old girl. Note the clip on the Botallian duct, which is situated in the right side of the mediastinum (arrow).

**Fig. 1.218a, b Coarctation of the aorta.** (a) A 14-year-old boy with coarctation of the aorta. As a result of hypertrophy of the intercostal arteries, inferior rib notching is seen (arrow). (b) Maximum intensity projection of a magnetic resonance angiography in another patient shows the coarctation of the aorta (arrow), hypertrophy of the intercostal arteries (arrowhead), and hypertrophy of the mammarian arteries (double arrowhead).

**Fig. 1.219 Coarctation of the aorta.** CT angiography surface-shaded three-dimensional rendered image of coarctation of the aorta in a 1-month-old boy.

**Fig. 1.220 Aneurysmal dilatation of the Botallian duct** (arrow). (Courtesy of J.I.L.M. Verbeke, Pediatric Radiologist, VU Medical Centre Amsterdam, the Netherlands.)

**Table 1.84 The large vessels, changes in contour of the pulmonary artery**
Diagnosis	Findings	Comments
Enlarged main pulmonary segment	Convex dilatation of the pulmonary vasculature.	Seen in pulmonary stenosis with poststenotic dilatation.
Small pulmonary artery (e.g., in tetralogy of Fallot)	The contour of the pulmonary artery is flat or concave.

**Table 1.85 The great vessels, changes in contour of the superior mediastinal veins**
Diagnosis	Findings	Comments
Absent silhouette of the superior vena cava	“Empty” superior vena cava contour.	Due to “rotation” of the heart due to the enlarging right atrium.
Persistent left superior vena cava and duplicated superior vena cava	Widening of the left superior mediastinum.	Can be seen as an isolated anomaly.
TAPVD (type I)	Bilateral widening of the mediastinum superior.

Coronary Artery Disease

Compared to adults, coronary artery disease in children is a rare finding; however, with the advent of modern imaging techniques, the pediatric radiologist should be aware of the pathology of coronary arteries.

**Table 1.86 Coronary artery disease**
Diagnosis	Findings	Comments
Congenital anomalies	Abnormal origin and course of coronary arteries: Absent left main trunk (split origination of left coronary artery) Anomalous location of coronary ostium within aortic root or near proper aortic sinus Anomalous location of coronary ostium outside normal aortic sinuses Anomalous origination of the coronary ostium from opposite, facing “coronary” sinus Single coronary artery.	The most common anomaly is an aberrant origin of the main left or right coronary artery from the wrong sinus of Valsalva. Often an incidental finding during coronary angiography, with an estimated incidence of 0.3%–0.8%.
	Anomalies of coronary arterial anatomy: Congenital ostial stenosis or atresia (left coronary artery, left anterior descencing [LAD] artery, right coronary artery [RCA], circumflex coronary artery [Cx] Coronary ectasia or aneurysm Coronary hypoplasia Intramural coronary artery (muscular bridge) Subendocardial coronary course Coronary crossing Anomalous origination of posterior descending artery from anterior descending branch or septal penetrating branch Absent posterior descending branch (PD) (split RCA) Absent LAD (split LAD) Ectopic origination of first septal branch.
	Anomalies of coronary termination: Inadequate arteriolar/capillary ramifications Abnormal communication of coronary arteries.	Congenital coronary artery fistula is a relatively rare anomaly defined as an abnormal direct communication between any coronary artery and any of the cardiac chambers. Coronary arteriovenous fistulas: an anomaly in which the coronary arteries have a direct communication with the pulmonary veins.
Stenosis	Narrowing of the lumen of the vessel. Unlike in adults, almost never based on atherosclerosis.	Can be seen in patients with Takayasu arteritis.
Dilatation Fig. 1.221 Fig. 1.222	Dilation, regional or over a longer trajectory, of the coronary arteries.	Can be seen in Kawasaki disease, LEOPARD syndrome (extremely rare).

**Fig. 1.221 Calcified coronary artery aneurysms** in a 17-year-old boy with Kawasaki disease.

**Fig. 1.222** Electrocardiography-gated CT angiography shows aneurysms of the RCA and LAD artery in a 13-year-old boy with Kawasaki disease.


D1	First diagonal branch of LAD
D2	Second diagonal branch of LAD
LCX	Left circumflex artery

Rings and Slings

A vascular ring is the result of anomalous development of the aortic arch. In the embryologic stage, the aorta forms a ring around the primitive foregut, and anomalous development leads to an aortic ring or sling.

Historically, the primary diagnostic tool was the contrast (barium) swallow; however, with the advent of CT and MRI, this technique has been superseded and should be considered obsolete.

In young children, the main presenting symptom may be stridor, often the result of concomittant tracheomalacia. Later in life, dysphagia is the most common symptom.

**Table 1.87 Aberrant arteries and vascular rings**
Diagnosis	Findings	Comments
Anomalous vessels with posterior esophageal and anterior tracheal impression Fig. 1.223a, b	Most commonly caused by double aortic arch.	In rare cases, seen in combined right aortic arch, left ductus arteriosus, and abberant subclavian artery.
Anomalous vessels with anterior tracheal impression and normal esophagus Fig. 1.224	Most commonly caused by an innominate artery or a single arterial trunk combining the innominate artery and the left common carotid artery.
Anomalous vessels with a small oblique esophageal impression and a normal trachea Fig. 1.225a–c	Most commonly caused by an aberrant right subclavian artery (lusorian artery).
Anomalous vessels with anterior esophageal impression and posterior tracheal narrowing Fig. 1.226a, b	Most commonly caused by a pulmonary sling or anomalous left pulmonary artery arising from the right pulmonary artery.