Recommendations for cardiovascular magnetic resonance and computed tomography in congenital heart disease: a consensus paper from the CMR/CCT working group of the Italian Society of Pediatric Cardiology (SICP) and the Italian College of Cardiac Radiology endorsed by the Italian Society of Medical and Interventional Radiology (SIRM) Part I

Abstract

Cardiovascular magnetic resonance (CMR) and computed tomography (CCT) are advanced imaging modalities that recently revolutionized the conventional diagnostic approach to congenital heart diseases (CHD), supporting echocardiography and often replacing cardiac catheterization. Nevertheless, correct execution and interpretation require in-depth knowledge of all technical and clinical aspects of CHD, a careful assessment of risks and benefits before each exam, proper imaging protocols to maximize diagnostic information, minimizing harm. This position paper, written by experts from the Working Group of the Italian Society of Pediatric Cardiology and from the Italian College of Cardiac Radiology of the Italian Society of Medical and Interventional Radiology, is intended as a practical guide for applying CCT and CMR in children and adults with CHD, wishing to support Radiologists, Pediatricians, Cardiologists and Cardiac Surgeons in the multimodality diagnostic approach to these patients. The first part provides a review of the most relevant literature in the field, describes each modality's advantage and drawback, making considerations on the main applications, image quality, and safety issues. The second part focuses on clinical indications and appropriateness criteria for CMR and CCT, considering the level of CHD complexity, the clinical and logistic setting and the operator expertise.

Keywords: Cardiovascular computed tomography; Cardiovascular magnetic resonance; Congenital heart disease; Multimodality imaging; Pediatric cardiology.

Fig. 1

CCT 3D volume rendering images, sagittal view of a 54-year-old woman with bypass aortic coarctation palliation (a). CCT 3D volume rendering images of a double aortic arch with 3D rendering of airways structures (asterisks) showing anatomical relationships between them and the vascular ring (b). CCT Cardiovascular computed tomography, 3D tridimensional

Fig. 2

CMR quantification of biventricular volumes through semiautomatic delineation of epicardial and endocardial borders in a ventricle base to apex stack of short axis slides: the absence of geometric assumptions and panoramicity assures optimal reproducibility and high measurement accuracy

Fig. 3

30-year-old female with repaired Tetralogy of Fallot (ToF). CMR SSFP image, RVOT sagittal plane shows a slightly reduced homograft caliber with post-stenosis pulmonary artery dilation (a). 21-year-old male after aortic coarctation and VSD repair. MRA MPR axial image shows residual pulmonary bifurcation and proximal branch arteries stenosis post pulmonary banding (b). 31-year-old female with repaired ToF. CMR SSFP 4-chamber view demonstrates right ventricular dilatation (c). CMR LGE short-axis view shows RVOT post-surgical scar (arrows) (d). CMR cardiovascular magnetic resonance, Hg Homograft, La left atrium, LPA left pulmonary artery, LGE late gadolinium enhancement, Lv left ventricle, MPA pulmonary artery, MPR Multiplanar Reformation, MRA Magnetic Resonance Angiography, Ra right atrium, RPA right pulmonary artery, Rv right ventricle, RVOT right ventricle outflow tract, SSFP Steady State Free Precession, VSD Ventricular septal defect

Fig. 4

31-year-old male with a repaired ToF. CCT MPR image, RVOT sagittal plane: infundibular and pulmonary stenosis (a), note the anatomical detail of valvular cusp (arrow). 16-year-old female with a cTGA after Arterial Switch operation. CCT 3D volume rendering images demonstrate high resolution post-surgical anatomy (b), LCA reimplantation kinking and stretching (black arrow) is well depicted (c). 2-year-old child with coronary artery fistula. CCT 3D volume rendering image optimally shows the fistula (white arrows) between LAD artery and Rv chamber (d). Ao Ascending aorta, CCT Cardiovascular computed tomography, cTGA Complete transposition of the great arteries, 3D Tridimensional, D Diagonal artery, LAD Left Anterior descending artery, LCA Left coronary artery, Lv Left ventricle, MPA Main pulmonary artery, MPR Multiplanar Reformation, RPA Right pulmonary artery, Rv Right ventricle, ToF Tetralogy of Fallot

Fig. 5

34-year-old male with Mustard repair of c-TGA and loop recorder implantation. CMR SSFP 4-chamber view shows atrio-ventricular concordance and the pulmonary baffle (asterisk). The ventricular apex is canceled by artifacts (a). 18-year-old Fontan patient with pacemaker implantation. CCT axial plane displays the wires and the pacemaker generator (arrows) with minimal artifacts upon thoracic aorta (b). Adult male patient with Mustard repair of c-TGA and baffle leakage. CMR SSFP 4-chamber images show the flow turbulence (arrow) before the treatment (c) and a huge artifact (arrow) caused by the metallic closure device (d). Adult male with ASD after endovascular closure. CCT axial image well depicts the closure device without limitations to cardiac chambers visualization (e). CCT cardiovascular computed tomography, CMR cardiovascular magnetic resonance, cTGA complete transposition of the great arteries, SSFP Steady State Free Precession, La left atrium, Lv left ventricle, Ra right atrium, Rv right ventricle

Fig. 6

Overview of some of the emergent imaging applications in CHD. T2 map in a short axis basal view of the ventricles in a RV dilatation due to left-to-right shunt (a). High complexity CHD 3D printing model: supero-inferior ventricle with a complex relationship of the ventricular septal defect (b). 4D flow reconstruction of thoracic aorta: flow streamlines panoramic sagittal oblique visualization in a bicuspid aortic valve patient. Color-coding of different flow velocities (c)