The pericardium could be involved in a variety of clinical disorders. The imaging findings are not specific for an individual pathology in most of the cases; however, patient\'s clinical history may guide radiologist to a definitive diagnosis. Congenital absence of the pericardium could be recognized with the imaging appearance of interposed lung tissue between the main pulmonary artery and aorta. Pericardial effusion is a non-specific condition that may occur due to inflammatory, infectious, and neoplastic disorders. Cardiac tamponade may occur in case of massive or rapid accumulation of fluid in the pericardial sac. Pericardial calcification is a common and easily identified entity on a computed tomography (CT) scan. Presence of calcification and/or fibrosis may result in pericardial constriction. Nevertheless, the pulsation of an adjacent coronary artery may prevent calcification formation in a focal area and consequently may result in pericardial diverticulum containing epicardial fat and coronary artery. The imaging findings encountered in patients with pericardial hydatid disease and Erdheim-Chester disease may mimic those of pericardial neoplasia. Pericardial adhesions and pedicled fat flaps may cause confusion on a CT scan in the post-surgical period following cardiac surgery. Pericardial fat necrosis can be diagnosed by CT in patients with chest pain. The radiologists should be familiar with the medical devices placed in pericardial space for certain individual indications. A pericardial patch and temporary epicardial pacemaker wires could be identified on a CT scan.

Congenital absence of the pericardium is a rare cardiac malformation and is most often asymptomatic. It is usually discovered as an incidental finding. Physical examination, chest radiography, and electrocardiogram are often unremarkable. Echocardiography provides valuable information, and sometimes computed tomography or magnetic resonance imaging is needed for subsequent confirmation.

We present a case of a patient with a cardiac malformation that represents a form of embryo-anatomical transition of an atrioventricular septal defect between a 2 valves form to a common valve form. This entity was associated with pericardium absence. Throughout several studies we have precisely established a diagnostic sequence by determining the adequate contribution of each method and we have been able to clear out the proper nomenclature of the atrioventricular cushion defect.