[Pericardial liquid layer as an occasional finding in internal echography. Normal patterns and pathologic limits]

A small amount of fluid in the pericardial sac is often observed incidentally during upper abdomen US studies. In order to assess the normality range for this finding, 500 patients undergoing liver US were evaluated for the presence of pericardial fluid, the thickness of which was subsequently measured in positive cases. In a group of 20 patients with pericardial fluid thickness ranging 5-9 mm and in 6 cases with pericardial effusion greater than 10 mm, cardiologic evaluation was performed (clinical examination, ECG, echocardiography). Pericardial fluid was quite a common finding (20.8%) which had no clinical relevance when less than 10 mm. On the contrary, its clinical relevance was high when greater than 10 mm, and extending around the heart.