Evaluation of pericardial effusion with computed tomography.

Evaluation of pericardial effusion was attempted with computed tomography in 11 patients. The volume and distribution of pericardial fluid were assessed with satisfactory resolution and the nature of the fluid was estimated by the difference in x-ray transparency (CT numbers). The volume of pericardial fluid calculated by tomographic methods ranged from 25 ml. to 585 ml. and agreed well with the surgically drained fluid volume. The CT numbers of the pericardial effusion due to renal or heart failure, acute viral pericarditis, hypothyroidism, and hemopericardium were +12 to +13, +20, +28 to +30, and +26 to +40, respectively. Therefore the volume and gross nature of the pericardial fluid could be estimated noninvasively with computed tomography.