Cardiac magnetic resonance imaging and computed tomography for the pediatric cardiologist

This review aims to provide an introduction to axial imaging, focusing on the basic physics, mode of acquisition and applications of magnetic resonance imaging and computed tomography in pediatric cardiology. Cardiac magnetic resonance imaging provides excellent assessment of ventricular size and function. Ventricular volumes together with phase contrast imaging provide important information about systemic flow, pulmonary flow, shunt volumes and regurgitant fraction. Three dimensional reconstructed images obtained by specific sequences as described in this review can be used to visualize detailed anatomy in palliated congenital heart disease while late gadolinium enhancement provides assessment of scar burden. Advanced modalities like four dimensional flow, parametric mapping, feature tracking and computational models have been briefly described. Due to excellent spatial resolution, cardiac computed tomography is increasingly used to evaluate coronary anatomy and complex anatomy in single ventricle patients. It offers the advantage of simultaneously assessing the airway and vasculature in neonates with arch anomalies. The technical basics of the scan and timing of administration of contrast have been briefly described. The safety profile of gadolinium based contrast agents in cardiac magnetic resonance imaging and radiation exposure in cardiac computed tomography has been highlighted. Both are complementary modalities, serving as an important diagnostic tool in the management of patients with congenital heart disease.