Obstructive lesions impede the flow through the left-sided chambers and the left ventricular outflow. These lesions are cor triatriatum, congenital mitral stenosis, aortic coarctation, and subvalvular, valvular, and supravalvular aortic stenosis. In cor triatriatum and congenital mitral stenosis, echocardiography has a primary imaging role, with MRI and CC supplementing to help detect anomalous pulmonary veins and detect pressure gradients, respectively. TTE is the initial imaging for supravalvular and subvalvular aortic stenosis and MRI is utilized when TTE is non-diagnostic. Echocardiography plays a primary role in valvular aortic stenosis ,and MRI and CT are complementary for evaluating aortic aneurysms and coarctation. Because aortic coarctation is an extracardiac lesion, both MRI and CT can better visualize the defect and are therefore the primary imaging modalities.