Discussion of Pneumopericardium
- Pneumopericardium is a well-necognized clinical and radiologic entity.
- Its causes include:
- Penetrating trauma
- Blunt trauma (rare)
- Infectious peticarditis with gas-producing organisms
- Fistula formation between the penicardium and an adjacent air-containing organ (i.e. stomach or esophagus))
 Imaging Findings for Pneumopericardium
 Plain film and CT
- The heart partially or completely surrounded by air, with the pericardium sharply outlined by air density on either side.
- Pneumopemicardium can usually be distinguished from pneumomediastinum, since air in the penicardial sac should not rise above the anatomic limits of the penicardial reflexion on the proximal great vascular pedicle. Also on radiographs obtained with the patient in the decubitus position, air in the pericamdial sac will shift immediately, while air in the mediastinum will not shift in a short interval between films.
- Occasionally, it may not be possible to distinguish pneumopenicardium from pneumomediastinum on plain film.
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 External Links
 References for Pneumopericardium
- SE Mirvis, M Indeck, RM Schorr, and JN Diaconis. Posttraumatic tension pneumopericardium: the "small heart" sign. Radiology 1986 158: 663-669.