Importance of Cardiovascular Magnetic Resonance Applied to Congenital Heart Diseases in Pediatric Age: A Narrative Review

Abstract

Congenital heart diseases (CHDs) represent a heterogeneous group of congenital defects, with high prevalence worldwide. Non-invasive imaging is essential to guide medical and surgical planning, to follow the patient over time in the evolution of the disease, and to reveal potential complications of the chosen treatment. The application of cardiac magnetic resonance imaging (CMRI) in this population allows for obtaining detailed information on the defects without the necessity of ionizing radiations. This review emphasizes the central role of CMR in the overall assessment of CHDs, considering also the limitations and challenges of this imaging technique. CMR, with the application of two-dimensional (2D) and tri-dimensional (3D) steady-state free precession (SSFP), permits the obtaining of very detailed and accurate images about the cardiac anatomy, global function, and volumes' chambers, giving essential information in the intervention planning and optimal awareness of the postoperative anatomy. Nevertheless, CMR supplies tissue characterization, identifying the presence of fat, fibrosis, or oedema in the myocardial tissue. Using a contrast agent for angiography sequences or 2D/four-dimensional (4D) flows offers information about the vascular, valvular blood flow, and, in general, the cardiovascular system hemodynamics. Furthermore, 3D SSFP CMR acquisitions allow the identification of coronary artery abnormalities as an alternative to invasive angiography and cardiovascular computed tomography (CCT). However, CMR requires expertise in CHDs, and it can be contraindicated in patients with non-conditional devices. Furthermore, its relatively longer acquisition time and the necessity of breath-holding may limit its use, particularly in children under eight years old, sometimes requiring anesthesia. The purpose of this review is to elucidate the application of CMR during the pediatric age.

Keywords: cardiac magnetic technique; congenital heart disease (CHD); magnetic resonance (CMR).

Figure 1

(A) 4-chamber cine SSFP image showing sinus venosus ASD (red arrow); (B) Angiographic reconstruction showing the right upper pulmonary artery draining into the superior vena cava (blue and yellow cross); (C) Basal short axis cine SSFP image; (D) sagittal RV three-chamber view showing perimembranous VSD (yellow arrow); (E) 4-chamber cine SSFP image showing aneurysmal formation of the basal septum involving adjacent septal leaflet of the tricuspid valve (white circle); (F) Sagittal cine SSFP image; and (G) MRA showing PDA: (arrow-heads). SSFP: steady-state free precession, ASD: atrial septal defect, RV: right ventricle, VSD: ventricular septal defect, PDA: patent ductus arteriosus.

Figure 2

Cine bSSFP image of D-TGA post-atrial switch operation using the Senning technique. The image shows the pulmonary veins (*) being redirected through the baffle into the right atrium and then to the subaortic positioned sRV.

Figure 3

Cine bSSFP image of D-TGA following an atrial switch operation using the Senning technique. This image illustrates the pathway of the systemic veins, with the superior vena cava (*) and the inferior vena cava (§) shown.

Figure 4

Reconstruction following angiographic sequences in TGA post-arterial switch operation. The image highlights a suprapulmonary stenosis (white arrows) at the level of the surgical suture of the switch with post-stenotic dilation.

Figure 5

D-TGA with pulmonary stenosis/atresia post-placement of the right ventricle to pulmonary artery (RV-PA) conduit. (A) shows a sagittal section, and (B) displays a transverse section, both highlighting the pulmonary conduit (marked with *).

Figure 6

Cine bSSFP image from a 15-year-old male with TOF, post complete correction and Melody valve implantation. The image shows significant migration of the Melody valve into the infundibulum (++).

Figure 7

Coronal Cine bSSFP image from a 12-year-old male TCPC with dextrocardia. The image illustrates two superior vena cava (*) and the external conduit (§).

Figure 8

Imaging from a 17-year-old male TCPC. (A) shows a coronal angiography image, while (B) presents a sagittal angiography image displaying a veno-venous fistula (marked with §) between the suprahepatic veins and the pulmonary veins.