A simplified approach for assessment of intracardiac baffles and extracardiac conduits in congenital heart surgery with two- and three-dimensional magnetic resonance imaging

Background Intracardiac baffles and extracardiac conduits have been used in the reconstructive surgery of a broad spectrum of congenital cardiac malfo rmations. Periodic evaluation of these structures may not lend. itself read ily to echocardiographic and angiographic imaging. The purpose of the study was to describe the experience of our institution with the use, of magneti c resonance imaging (MRI) in evaluating conduits and baffles and to describ e the simplified approach we developed to image these structures, which all ows for grouping individual lesions into broad categories. Methods and Results We retrospectively reviewed our MRI experience in visua lizing these structures from 1989-1996. One hundred thirty-nine patients un derwent MRI to visualize 144 structures (116 baffles, 28 conduits). The 116 baffles included 86 Fontan, 16 Mustard, 6 Senning, 6 left ventricle to aor ta, I right ventricle to aorta, and 1 pulmonary vein to left atrium baffle. The 28 conduits included 15 right ventricle to pulmonary artery, 4 left ve ntricular apical to aorta, 2 left ventricle to pulmonary artery, 3 aorta to aorta, 2 inferior vena cava to left atrium conduits, and 2 aortic root rep lacements. Of the 3 aortic-aortic conduits, 1 was in conjoined twins. Both inferior vena cava-left atrial conduits were in a Baffes procedure. An infe ctious mass missed by echocardiography in a right ventricle to pulmonary ar tery conduit was visualized by MRL With multiplanar reconstruction, contigu ous images were stacked atop each other and resliced to define the salient points of the anatomy. Three-dimensional reconstruction further added to th is delineation. All structures were visualized successfully, and an assessm ent of obstruction was made. Multiple examples of conduit and baffle narrow ing were diagnosed by spin echo and cine MRI and were subsequently confirme d by catheterization and surgical inspection. Conclusion MRI, with multiplanar and 3-dimensional reconstruction, is usefu l in examining the variety of baffles and conduits used in congenital heart surgery. MRI can add to the care of patients whose echocardiographic windo ws or whose angiographically overlapping structures do not allow adequate d elineation of conduits and baffles.