Imaging Sciences Interesting Cases
Case 283
Neal Young, MD
Clinical Presentation: Patient is a 51 year-old male with a history of bulbous lung disease and emphysema. Eight months before this exam, he was involved in a motor vehicle accident and suffered several rib fractures, but no pneumopericardium was visualized at the time of trauma. Now he presented with worsening dyspnea.
Imaging Findings: Figure 1 demonstrates air outlining the heart border, bulbous disease and chronic interstitial disease and Figure 2 from a contrast enhanced CT demonstrates a large pneumopericardium with shift of the heart to the right. Left-sided bulla and pulmonary fibrosis are also noted.
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Figure 1: Frontal view of the chest. |
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| Figure 2: Axial view of the chest.
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Diagnosis: Pneumopericardium
Discussion: Pneumopericardium, usually has a traumatic etiology (penetrating, surgical, fistula, Bertram). Pneumopericardium consists of free air tracks from ruptured alveoli along provincial vascular sheaths toward the chillum of the lung. From there, it extends proximally within the mediastinum.
While rarely leading to clinically significant complications, diminished cardiac output because of direct cardiac compression or reduced venous return can be life threatening. When extensive subcutaneous and mediastinal gas is present, airway compression may also occur.
In pneumopericardium air is confined to a gas collection outlining the left ventricle, right atrium, or both if large enough, but does not extend above the mid-ascending aorta. Compression of the superior vena cava or right ventricular cavity are signs of tension pneumopericardium.
References:
- Zylak CM, Standen JR, Barnes GR, Zylak CJ. Pneumomediastinum revisited. Radiographics. 2000 Jul-Aug;20(4):1043-57. PMID: 10903694 [PubMed]
- Newcomb AE, Clarke CP. Spontaneous pneumomediastinum: a benign curiosity or a significant problem?. Chest. 2005 Nov;128(5):3298-302. PMID: 16304275 [PubMed]