[Pericardial effusion with involvement of the superior aortic recessus of the pericardium. An x-ray computed tomographic case].

Computed tomography imaging in a patient with a pericardial effusion showed fluid collection in the superior recessus of pericardium confirmed by mediastinoscopy. Topographic and morphologic criteria and anatomic bases of the radiologic diagnosis are described, and emphasis placed on the fact that because of density variations in pericardial effusions the latter has to be added to the already long list of abnormal opacities of Barety's space.