Imaging considerations in tetralogy of Fallot: A comprehensive review

Table 4 Imaging modalities and their use in different stages of care in patients with tetralogy of Fallot

Stage of care	Imaging modality	Information provided	Advantages
At initial diagnosis	TTE	Defines the position of the VSD, degree of aortic override, and location and severity of the RVOT obstruction	Widely available, safe (no radiation), and assesses the basic defects
	CMR	Assessment of pulmonary arteries- size/confluence; MAPCAs	High-resolution, objective data on ventricular volumes, function, and pulmonary artery anatomy without using ionizing radiation
	CT angiography - as an alternative to CMR, however choice depends upon centre to centre; should preferably be an ECG-gated acquisition	Detailed assessment of pulmonary artery anatomy and branches; MAPCAs; coronary arteries anatomy; additional defects: ASD; PAPVC, muscular VSD	High spatial and temporal resolution, compared with CMR, less time is required for data acquisition
Post-surgical shunts	CT angiography	Shunt patency, stenosis	High accuracy
Post-intra-cardiac repair	CMR	Quantification of PR; RV volume and function; complications: RVOT aneurysms and myocardial fibrosis	Highly accurate and gold standard for volumetry
	Catheter angiography	Assessment of residual stenosis in pulmonary arteries and management (balloon dilation or stenting); management of residual VSDs; percutaneous PVR procedures	Diagnosis and therapeutic interventions

TTE: Transthoracic echocardiography; VSD: Ventricular septal defect; RVOT: Right ventricular outflow tract; CMR: Cardiac magnetic resonance; MAPCAs: Major aortopulmonary collateral arteries; CT: Computed tomography; ECG: Electrocardiogram; ASD: Atrial septal defect; PAPVC: Partial anomalous pulmonary venous connection; PR: Pulmonary regurgitation; RV: Right ventricular; PVR: Pulmonary valve replacement.