Role of Multidetector CT in Assessment of Repaired Tetralogy of Fallot

The population of adults with repaired tetralogy of Fallot (TOF) is growing, thanks to improvements in the surgical and medical management of this condition. Accordingly, late postrepair complications are important medical concerns in these individuals. Initial surgical repair of TOF typically occurs in infancy, consisting of patch repair of the ventricular septal defect (VSD) and relief of right ventricular outflow tract (RVOT) obstruction. Although patients may remain asymptomatic for several decades, the majority will have progressive pulmonic regurgitation that leads to right ventricular (RV) dilatation and functional deterioration. Other frequently seen complications include branch pulmonary artery stenosis, RVOT aneurysms, and recurrent VSDs. Cardiac computed tomography (CT) is widely available and, in some cases, is the imaging modality of choice for serial evaluation of TOF patients. CT is particularly useful when magnetic resonance (MR) imaging is contraindicated (eg, in patients with implantable cardiac devices). Unlike MR imaging, cardiac CT allows excellent visualization of endovascular stents and stent-mounted valves. Retrospective electrocardiographically gated cardiac CT can be used for accurate volumetric and functional analysis of the RV. Comprehensive serial evaluation will assist in determining the need for surgical pulmonary valve repair in the setting of progressive RV dysfunction. Three-dimensional volumetric images are useful for evaluation of stent integrity and aneurysm formation. The radiologist should be familiar with the anatomy of TOF, surgical interventions for repair, and postrepair complications encountered at follow-up imaging of these patients. By extracting the breadth of information obtained with cardiac multidetector CT, the radiologist can play an essential role in the management of adult patients with repaired TOF.