Evaluation with Cardiovascular MR Imaging of Baffles and Conduits Used in Palliation or Repair of Congenital Heart Disease

A wide array of baffles and conduits are used in repair or palliation of congenital heart disease, which is the most common major birth defect, often with complex redirection of blood flow to achieve a more stable physiology. Cardiovascular magnetic resonance (CMR) imaging is an increasingly used modality for noninvasive assessment of anatomy and physiology both before and after surgical intervention, with highly reproducible measurements of ventricular size and function, quantification of valvular insufficiency and flow volumes, and excellent delineation of intracardiac and extracardiac anatomy. The authors review the indications, appearances on CMR images, and potential complications of various cardiovascular baffles and conduits: Mustard and Senning procedures, venoatrial baffles, intraventricular baffles, ventriculoarterial conduits, and baffles and conduits used in functional single-ventricle palliation. CMR imaging offers the most complete evaluation of single- ventricle anatomy and physiology, demonstrating the anatomy of venous pathways and pulmonary arteries and quantifying systemic ventricular size and systolic function, differential pulmonary blood flow, ratio of pulmonary to systemic blood flow, and aortopulmonary collateral flow. Anatomic and physiologic considerations are discussed, and suggested CMR imaging protocols and practical advice for performing and interpreting CMR studies are provided. The diversity and complexity of baffles and conduits complicates performance and interpretation of studies in this population, but a fundamental understanding of the goals of the procedure, postoperative physiology, and potential complications allows targeted imaging and precise reporting of clinically significant findings. Supplemental material available at http://radiographics.rsna.org/lookup/suppl/doi:10.1148/rg.323115096/-/DC1. (C) RSNA, 2012 . radiographics.rsna.org