Presentation
Acute dyspnea. Recent long-haul flight.
Patient Data
Age: 90 years
Gender: Female
From the case:
Knuckle sign - pulmonary embolism
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Disproportionately large right lower lobe pulmonary artery.
From the case:
Knuckle sign - pulmonary embolism
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Multiple pulmonary emboli with right lower lobe predominance.
Hiatal hernia is also noted.
Case Discussion
Abrupt tapering of a major pulmonary artery is a rare chest x-ray sign of pulmonary embolism, and is known as the knuckle sign.