Multimodality Imaging Assessment of Tetralogy of Fallot: From Diagnosis to Long-Term Follow-Up

Abstract

Tetralogy of Fallot (TOF) is the most common complex congenital heart disease with long-term survivors, demanding serial monitoring of the possible complications that can be encountered from the diagnosis to long-term follow-up. Cardiovascular imaging is key in the diagnosis and serial assessment of TOF patients, guiding patients' management and providing prognostic information. Thorough knowledge of the pathophysiology and expected sequalae in TOF, as well as the advantages and limitations of different non-invasive imaging modalities that can be used for diagnosis and follow-up, is the key to ensuring optimal management of patients with TOF. The aim of this manuscript is to provide a comprehensive overview of the role of each modality and common protocols used in clinical practice in the assessment of TOF patients.

Keywords: Tetralogy of Fallot; cardiovascular imaging; congenital heart disease; paediatric cardiology.

Figure 1

Echocardiographic assessment of a patient with TOF and previous transcatheter pulmonary valve replacement (melody): in the left upper corner a right-ventricular focused four-chamber view; in the right upper corner a colour Doppler imaging of the right ventricular outflow tract with Melody valve implantation; in the left lower corner a global longitudinal strain of the right ventricle; in the right lower corner the TAPSE evaluation and the gradient assessment through the Melody valve.

Figure 2

A 40-year-old patient born with TOF and an absent pulmonary valve, post complete TOF repair (7 years of age). Subsequent pulmonary valve replacement with a 23 mm aortic homograft at the age of 32 due to severe pulmonary regurgitation: (A) bSSFP sequence showing unobstructed RVOT with patch used during the repair (white arrow) (B) bSSFP cine sequence acquired in the transaxial plane illustrating dilated PA (right PA (RPA) and left PA (LPA)) and mild acceleration flow in the main pulmonary artery (yellow arrow). (C) bSSFP cine sequence showing a dilated aortic root. (D) A second patient was born with TOF and underwent total repair in the first years of life. The 3D whole heart sequence to show the PAs anatomy.

Figure 3

CCT in a 2-day-old newborn with Tetralogy of Fallot, scanned in sedation and free-breathing at high heart rate (145 bpm), using a low-dose protocol (80 kV) and prospective ECG triggering. The main features are also detected and depicted in the images in multiplanar and curved reformation (MPR-CPR) and maximum intensity projection (MIP): ventricular septal defect and overriding aorta (black asterisk), PFO (black arrowhead), pulmonary valve atresia and pulmonary artery hypoplasia (white arrow), and major aortopulmonary collateral arteries (white asterisks). Despite the very high heart rate, in a low-birth-weight preterm baby (2.3 Kg) scanned at a high heart rate, the left coronary artery is detectable (white arrowhead).