Radiography Chest The chest radiograph in TOF patients with severe PR often demonstrates increased cardiothoracic ratio on frontal view and retrosternal fullness on the lateral view due to cardiomegaly secondary to RV volume overload. The chest radiograph may also demonstrate dilated pulmonary trunk and may demonstrate dilatation of the ascending aorta [9]. In the posttreatment setting, radiography is essential to monitor location and integrity of stents in the pulmonary arteries, screen for RVOT pseudoaneurysm after conduit placement, and screen for asymmetry in the size and branching pattern of the parenchymal pulmonary arteries, which may indicate the presence of proximal vessel hypoplasia or stenosis. Perfusion Scan Lung The use of pulmonary perfusion scintigraphy allows for the assessment of differential pulmonary blood flow in patients with TOF and branch pulmonary artery stenosis or hypoplasia [12]. SPECT/CT MPI Rest and Stress Radionuclide angiography may be performed to assess LV function but has been replaced by MRI in this setting. Its use to assess RV function is limited by the confounding effect of counts from other chambers. In addition, its resolution is poor compared with other imaging methods and, therefore, has been of limited use in this setting. Congenital or Acquired Heart Disease US Echocardiography Transesophageal Transesophageal echocardiography (TEE) is considered a useful technique for intraoperative assessment of adequacy of outflow tract repair in terms of ruling out any residual obstruction or valve regurgitation as a consequence of surgery. TEE offers the advantages of permitting visualization of the operative procedure in real time and providing guidance for the surgeon [6,18] . The routine use of TEE during follow-up after surgery for patients with TOF is not established.
Congenital or Acquired Heart Disease. Radiography Chest The chest radiograph in TOF patients with severe PR often demonstrates increased cardiothoracic ratio on frontal view and retrosternal fullness on the lateral view due to cardiomegaly secondary to RV volume overload. The chest radiograph may also demonstrate dilated pulmonary trunk and may demonstrate dilatation of the ascending aorta [9]. In the posttreatment setting, radiography is essential to monitor location and integrity of stents in the pulmonary arteries, screen for RVOT pseudoaneurysm after conduit placement, and screen for asymmetry in the size and branching pattern of the parenchymal pulmonary arteries, which may indicate the presence of proximal vessel hypoplasia or stenosis. Perfusion Scan Lung The use of pulmonary perfusion scintigraphy allows for the assessment of differential pulmonary blood flow in patients with TOF and branch pulmonary artery stenosis or hypoplasia [12]. SPECT/CT MPI Rest and Stress Radionuclide angiography may be performed to assess LV function but has been replaced by MRI in this setting. Its use to assess RV function is limited by the confounding effect of counts from other chambers. In addition, its resolution is poor compared with other imaging methods and, therefore, has been of limited use in this setting. Congenital or Acquired Heart Disease US Echocardiography Transesophageal Transesophageal echocardiography (TEE) is considered a useful technique for intraoperative assessment of adequacy of outflow tract repair in terms of ruling out any residual obstruction or valve regurgitation as a consequence of surgery. TEE offers the advantages of permitting visualization of the operative procedure in real time and providing guidance for the surgeon [6,18] . The routine use of TEE during follow-up after surgery for patients with TOF is not established.