The Initial Diagnostic Approach to Adult Congenital Heart Disease: A Practical Imaging Pathway for General Cardiologists and Cardiac Imagers.

Adult congenital heart disease (ACHD) is among the most anatomically and physiologically complex domains in cardiovascular medicine. Advances in pediatric cardiac surgery and cardiology have shifted congenital heart disease (CHD) from a predominantly pediatric condition to a lifelong disease, resulting in a growing adult population that now outnumbers the affected children. In addition, increased detection of CHD in adulthood has broadened the spectrum of ACHD encountered outside specialized centers, underscoring the importance of familiarity among general cardiologists and cardiac imagers. This state-of-the-art review outlines a structured imaging approach for adults with suspected or known CHD. The proposed pathway includes four stages: (1) clinical-anatomic orientation with systematic review of prior data including operative notes and prior imaging; (2) protocolized adult congenital transthoracic echocardiography using sequential segmental analysis; (3) question-driven cardiac magnetic resonance (CMR) with flow quantification; and (4) selective use of cardiac computed tomography (CCT) for detailed cardiac and extracardiac anatomy, coronary artery origins, surgical planning, sternal re-entry and cannulation or in cases of hardware-related imaging limitations. Beyond modality selection, we address the specialized protocol requirements, training milestones, and competency standards expected of ACHD sonographers, CMR, and CCT technologists-all personnel whose expertise is central to diagnostic quality and accuracy in this patient population. Lesion-specific scenarios and case examples illustrate application in practice. A multimodality and team-based strategy supported by standardized protocols and structured reporting is the foundation of accurate, safe, and efficient ACHD imaging in contemporary cardiovascular practice.