The pericardium is a double-layered sac that encloses the heart, consisting of an outer fibrous layer and an inner serous layer. Between these layers is a small amount of fluid (normally about 15 to 50 milliliters) that lubricates the heart’s movement during beating. On echocardiography, the pericardium appears as a bright, echogenic line surrounding the heart. The pericardium anchors the heart in the chest, protects it from infection, and prevents it from overfilling. Diseases of the pericardium include pericarditis, pericardial effusion, cardiac tamponade, and constrictive pericarditis, all of which can be evaluated with echocardiography.
Sonography Term