Cardiac magnetic resonance (MR) imaging plays a crucial role in assessing congenital heart disease, offering detailed anatomical and functional evaluations. Initially used alongside echocardiography, it now serves as a primary tool for evaluating shunts, mixed lesions, transpositions, and surgical corrections. Unlike X-ray angiography, cardiac MR is noninvasive, without iodinated contrast or radiation, making it suitable for both children and adults. The basic protocol for congenital heart disease imaging involves black-blood techniques for anatomy and bright-blood cine techniques for shunts, valves, and ventricular function. For young children, non-breath-hold black-blood methods like HASTE or FSE are optimal. Segmented k-space cine gradient echo images, such as true FISP, provide better results in shorter times. Cine images are vital for diagnosing small shunts and assessing surgically created ones. Bright-blood cine images can qualitatively assess valvular disease and shunt size. Phase-contrast imaging helps quantify shunts and calculate pressure gradients. Contrast-enhanced techniques are best for assessing pulmonic stenoses in specific conditions. The basic protocol takes 30-45 minutes, with additional time for alternate protocols. Equipment includes high gradient strength MR systems and fast rise times. Patients must be screened for contraindications, and sedation may be needed for young children. ECG leads are placed for cardiac gating, and patients are instructed on breath-holding. Imaging sequences include rapid multi-plane scout, HASTE, T1-weighted TSE, and cine gradient echo. These sequences provide detailed images of the heart, including small defects and valve assessments. For intracardiac shunt assessment, phase contrast sequences determine shunt direction and quantify flow. Valve assessment uses cine images to evaluate stenosis and regurgitation. Great vessel assessment involves contrast-enhanced sequences to evaluate anomalies like aortic or pulmonary stenoses. Key parameters include proper ECG gating, short TR times, and adequate temporal resolution. Troubleshooting involves ensuring good ECG tracings, minimizing motion artifacts, and using appropriate sequences for different patient needs. Cardiac MR is ideal for congenital heart disease, providing both anatomical and functional information, and is essential for surgical planning and follow-up.Cardiac magnetic resonance (MR) imaging plays a crucial role in assessing congenital heart disease, offering detailed anatomical and functional evaluations. Initially used alongside echocardiography, it now serves as a primary tool for evaluating shunts, mixed lesions, transpositions, and surgical corrections. Unlike X-ray angiography, cardiac MR is noninvasive, without iodinated contrast or radiation, making it suitable for both children and adults. The basic protocol for congenital heart disease imaging involves black-blood techniques for anatomy and bright-blood cine techniques for shunts, valves, and ventricular function. For young children, non-breath-hold black-blood methods like HASTE or FSE are optimal. Segmented k-space cine gradient echo images, such as true FISP, provide better results in shorter times. Cine images are vital for diagnosing small shunts and assessing surgically created ones. Bright-blood cine images can qualitatively assess valvular disease and shunt size. Phase-contrast imaging helps quantify shunts and calculate pressure gradients. Contrast-enhanced techniques are best for assessing pulmonic stenoses in specific conditions. The basic protocol takes 30-45 minutes, with additional time for alternate protocols. Equipment includes high gradient strength MR systems and fast rise times. Patients must be screened for contraindications, and sedation may be needed for young children. ECG leads are placed for cardiac gating, and patients are instructed on breath-holding. Imaging sequences include rapid multi-plane scout, HASTE, T1-weighted TSE, and cine gradient echo. These sequences provide detailed images of the heart, including small defects and valve assessments. For intracardiac shunt assessment, phase contrast sequences determine shunt direction and quantify flow. Valve assessment uses cine images to evaluate stenosis and regurgitation. Great vessel assessment involves contrast-enhanced sequences to evaluate anomalies like aortic or pulmonary stenoses. Key parameters include proper ECG gating, short TR times, and adequate temporal resolution. Troubleshooting involves ensuring good ECG tracings, minimizing motion artifacts, and using appropriate sequences for different patient needs. Cardiac MR is ideal for congenital heart disease, providing both anatomical and functional information, and is essential for surgical planning and follow-up.