Pericardial effusion simulating aortic dissection.

The rapid widening of the mediastinal shadow is a very common radiological sign of acute aortic dissection1 2 and can suggest this condition in the proper clinical setting.3 In the presence of pericardial effusion, "bottle shape" configuration of the cardiac silhouette,4 straightening ofits contours,5 and acute cardiophrenic angles5 6 have been emphasised. Broadening of the mediastinal shadow has also been mentioned.46 We describe two examples of pericardial effusion, whose radiographic appearance and clinical presentation simulated acute aortic dissection.