Computed tomography in tetralogy of Fallot: pre- and postoperative imaging evaluation

Tetralogy of Fallot (TOF) is the most common cause of cyanotic congenital heart disease (CHD) and the most frequent complex CHD encountered in adulthood. Although children with TOF share four characteristic features (subaortic ventricular septal defect, overriding aorta, right ventricular hypertrophy, pulmonary stenosis), the clinical spectrum and course are in fact greatly heterogeneous. Echocardiography remains the mainstay for diagnosis, presurgical planning and postoperative follow-up. However, with continued technological advances, CT now plays an increasing role in TOF evaluation and management, helping to minimize routine invasive catheter angiography. Preoperatively, CT is uniquely suited to assess associated pulmonary arterial, aortic and coronary anomalies as well as extra-cardiovascular structures and is particularly helpful for delineating complex anatomy in the TOF subtypes of absent pulmonary valve and pulmonary atresia with major aortopulmonary collaterals. Postoperatively, CT is useful for identifying surgical complications and for long-term monitoring including volumetry quantification, especially in children for whom MRI is contraindicated or limited by implanted devices such as pacemakers and stents. In this article, we review key clinical features and considerations in the pre- and postoperative TOF patient and the burgeoning role of CT for facilitating accurate diagnosis and personalized intervention.