Comparative Effectiveness of Gadopiclenol for Evaluation of Adult Congenital Heart Anatomy and Hemodynamics

The goal of this clinical trial is to learn how well and at what doses gadopiclenol, a new intravenous (IV) contrast agent used for MRI, works to produce high-quality MRI images of the heart, in patients with a history of congenital heart disease, when compared to gadobenate dimeglumine, the IV contrast agent that is normally used at our institution for heart (cardiac) MRI. The main questions it aims to answer are: * Does using gadopiclenol result in similar or superior image quality, similar signal-to-noise ratio (SNR), and similar flow measurements with 4-dimensional (4D) flow cardiac MRI when compared to gadobenate dimeglumine? * At what dose(s) does gadopiclenol result in similar image quality (using the above metrics) for cardiac MRI when compared to gadobenate dimeglumine? Researchers will compare cardiac MRI images obtained after administration of gadopiclenol to cardiac MRI images obtained after administration of gadobenate dimeglumine (called the standard of care treatment) to see if the images are of similar or superior quality. Participants will: * Be randomized to receive either gadopiclenol at one of three different doses or gadobenate dimeglumine before their congenital heart cardiac MRI * Undergo their congenital heart cardiac MRI as they would during the course of normal clinical care.