Cardiac MR Imaging and MR Angiography for Assessment of Complex Tetralogy of Fallot and Pulmonary Atresia

Breath-hold electrocardiographically gated cardiac magnetic resonance (MR) imaging and contrast material-enhanced MR angiography are emerging as ideal techniques for the evaluation of complex congenital heart disease. Tetralogy of Fallot is the most common cause of cyanotic congenital heart disease and, in its classic form, is associated with varying degrees of hypoplasia of the central and peripheral pulmonary arteries, with valvar pulmonary atresia and collateral aortopulmonary vessels occupying the extreme end of the spectrum. Accurate assessment of the size and anatomy of the pulmonary arteries is often difficult with echocardiography and conventional cineangiography. Compared with echocardiography in particular, cardiac MR imaging with three-dimensional reconstruction has distinct advantages for pre- or postoperative assessment of pulmonary anatomy in patients with tetralogy of Fallot and pulmonary atresia. MR imaging enables the clear and complete depiction of anatomy and thus can provide additional information about pulmonary artery abnormalities that are difficult to evaluate with conventional cardiac imaging techniques.