1a Answer D. The patient is status post arterial switch operation and a LeCompte maneuver for transposition of the great arteries. In this surgery, the coronaries are excised from the aorta and the ascending aorta, and main pulmonary artery is switched. The LeCompte maneuver involves placing the ascending aorta (asterisks) posterior to the bifurcation of the main pulmonary artery. This maneuver reduces the risk of compression or kinking of the coronary arteries.

Reference: Gaca AM, Jaggers JJ, Dudley LT, et al. Repair of congenital heart disease: a primer—part 1. Radiology 2008;247:617-631.

1b Answer B. In dextrotransposition of the great arteries (D-TGA), there is ventriculoarterial discordance but atrioventricular concordance. The aorta arises from the morphological right ventricle, and the main pulmonary artery arises from the morphological left ventricle. The left atrium enters the left ventricle, and the right atrium enters the right ventricle consistent with atrioventricular concordance. In congenitally corrected or L-transposition of the great arteries (L-TGA), there is atrioventricular and ventriculoarterial discordance.

References: Gaca AM, Jaggers JJ, Dudley LT, et al. Repair of congenital heart disease: a primer—part 1. Radiology 2008;247:617-631.

Warnes CA. Transposition of the great arteries. Circulation 2006;114:2699-2709.

1c Answer D. An obstructed coronary artery leading to myocardial ischemia is the most common cause of morbidity and mortality following an arterial switch operation (ASO) for d-TGA. This risk is most common in the initial 3 months following ASO. Additionally, neoaortic root dilation occurs in nearly all patients post ASO, and neoaortic valve regurgitation occurs in most patients post ASO. Less common long-term sequelae are supravalvular pulmonary stenosis and aortic stenosis.

Reference: Villafane J, Lantin-Hermoso MR, Bhatt AB, et al. D-transposition of the great arteries. J Am Coll Cardiol 2014;64:498-511.

2a Answer B. The characteristic appearance of Ebstein anomaly on a chest radiograph is marked cardiomegaly with decreased pulmonary vascularity. Although tetralogy of Fallot also may present with decreased vascularity on radiograph, it does not typically present with marked cardiomegaly.

In Ebstein anomaly, there is displacement of the septal and posterior leaflets (arrows) of the tricuspid valve into the right ventricle forming an atrialized portion of the right ventricle.

Reference: Epstein ML. Tricuspid atresia, stenosis, and regurgitation. In: Moss AJ, Allen HD, eds. Moss and adams’ heart disease in infants, children, and adolescents: including the fetus and young adult, 7th ed. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2008:817-834.

2b Answer C. Although the degree of abnormality varies in patients with Ebstein anomaly, the pulmonary vascularity would be typically decreased. During ventricular systole, much of the cardiac output is sent retrograde into the true right atrium rather than antegrade into the true right ventricle and main pulmonary artery.

Reference: Epstein ML. Tricuspid atresia, stenosis, and regurgitation. In: Moss AJ, Allen HD, eds. Moss and adams’ heart disease in infants, children, and adolescents: including the fetus and young adult, 7th ed. Philadelphia, PA: Wolters Kluwer Health/Lippincott Williams & Wilkins, 2008:817-834.

2c Answer E. Management of Ebstein anomaly can be variable depending on the severity of the disease. Biventricular repair involving tricuspid valvuloplasty such as cone reconstruction may be performed. Tricuspid valve replacement is another surgical procedure used in Ebstein anomaly repair. Single ventricle repair involving a bidirectional cavopulmonary anastomosis (Glenn) and/or a total cavopulmonary anastomosis (Fontan) may be needed for a poorly functioning right ventricle.

References: Gaca AM, Jaggers JJ, Dudley T, et al. Repair of congenital heart disease: a primer-part 1. Radiology 2008;247:617-631.

Jinghao Z, Kai L, Yanhui H, et al. Individualized surgical treatments for children with Ebstein anomaly. Thorac Cardiovasc Surg 2016 [Epub ahead of print].

3a Answer A. On the chest radiograph, there is a prominent vessel within the right hemithorax (arrow in Fig. A) consistent with an anomalous pulmonary vein draining to the inferior vena cava. This finding is consistent with a right lower lobe anomalous pulmonary venous connection. The pulmonary veins normally drain into the left atrium. In partial anomalous pulmonary venous, some of the veins drain anomalously into the systemic venous system rather than to the left atrium (arrow in Fig. B).

In this case, the right lung is also decreased in size in comparison to the left with elevation of the right hemidiaphragm. This finding in addition to the partial anomalous pulmonary venous return is consistent with hypogenetic lung syndrome or scimitar syndrome. In this syndrome, the right lung partially drains to the inferior vena cava with a variable degree of lung hypoplasia. The right pulmonary artery may be hypoplastic or aplastic.

Reference: Konen E, Raviv-Zilka L, Cohen RA, et al. Congenital pulmonary venolobar syndrome: spectrum of helical CT findings with emphasis on computerized reformatting. Radiographics 2003;23:1175-1184.

3b Answer B. As noted above, this patient presents with not only partial anomalous pulmonary venous return (PAPVR) but also hypogenetic lung syndrome or scimitar syndrome. Patients with scimitar have associated anomalies including congenital heart disease, particularly sinus venosus atrial septal defects (ASD), bronchogenic cysts, accessory diaphragms, and hernias. Scimitar syndrome is also associated with horseshoe lung where an isthmus of the right lung base extends posteriorly joining the posterobasal segments of the right and left lung.

Reference: Konen E, Raviv-Zilka L, Cohen RA, et al. Congenital pulmonary venolobar syndrome: spectrum of helical CT findings with emphasis on computerized reformatting. Radiographics 2003;23:1175-1184.

3c Answer C. A chest radiograph is the initial screening modality used to evaluate patients with suspected partial anomalous pulmonary venous return (PAPVR). Given that it is noninvasive, echocardiogram is the next imaging modality in evaluating pediatric patients with this disorder. If additional imaging is desired, cross-sectional imaging such MRI/MR angiography and CT/CT angiography can be performed. MRI is usually preferred given the lack of ionizing radiation and the ability to characterize pulmonary and systemic flow. CT would be preferred if evaluation of the lung parenchyma is desired. Cardiac catheterization is performed for endovascular procedures or if additional hemodynamic data is needed.

Reference: Sung LY, Ting C, Varghese C, Hellinger JC. Scimitar syndrome. In: Reid JR, Paladin A, Davros WJ, et al. (eds). Pediatric radiology. New York, NY: Oxford University Press, 2013:105-109.

4a Answer C. The most likely diagnosis is a cardiac fibroma. Fibromas are low in signal on balanced gradient echo imaging (arrow), do not demonstrate first-pass perfusion (+), and do demonstrate myocardial delayed enhancement (asterisk). Rhabdomyoma could be considered, but rhabdomyomas do not demonstrate myocardial delayed enhancement.

The table below describes characteristics of select pediatric cardiac masses (from Beroukhim et al. 2011).

Reference: Beroukhim RS, Prakash A, Buechel ERV, et al. Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging. J Am Coll Cardiol 2011;58:1044-1054.

4b Answer C. Cardiac fibromas demonstrate strong delayed hyperenhancement on myocardial delayed imaging. They are most often heterogeneous on T1- and T2-weighted imaging. They do not demonstrate first pass perfusion. The lesions are most often echogenic on echocardiography. There location is usually intramyocardial involving either the ventricular septum or ventricular free wall.

References: Beroukhim RS, Prakash A, Buechel ERV, et al. Characterization of cardiac tumors in children by cardiovascular magnetic resonance imaging. J Am Coll Cardiol 2011;58:1044-1054.

Grebenc ML, Rosado de Christenson M, Burke AP, et al. Primary cardiac and pericardial neoplasms: radiologic-pathologic correlation. Radiographics 2000;20:1073-1103.

4c Answer A. Cardiac fibromas may be stable for years or even regress. Although one-third of patients may be asymptomatic, presenting symptoms may include arrhythmias, heart failure, or sudden death. If patients are symptomatic, these tumors are resected. Patients may even benefit from partial resection of more extensive tumors. Postsurgical recurrence is rare.

Reference: Grebenc ML, Rosado de Christenson M, Burke AP, et al. Primary cardiac and pericardial neoplasms: radiologic-pathologic correlation. Radiographics 2000;20:1073-1103.

5a Answer B. The images demonstrate the right coronary artery (arrow) originating for the left coronary cusp consistent with an anomalous right coronary artery. The right coronary artery takes a tangential course to the aortic root and an interarterial course between the right ventricular outflow tract on the aorta.

Reference: Shriki JE, Shinbane JS, Rashid MA, et al. Identifying, characterizing, and classifying congenital anomalies of the coronary arteries. Radiographics 2012;32:453-468.

5b Answer D. Although history and physical examination is initially used to screen patients for coronary artery anomalies, imaging modalities are needed for detection. Cross-sectional imagings, such as MRA and CTA, are modalities often used to directly visualize the origin of the coronary arteries. Echocardiography can also be used, but this modality is less precise than cross-sectional imaging.