Pulmonary artery dissection is a serious fatal complication of chronic pulmonary arterial hypertension, always occurring at the site of maximal dilatation of the artery. Diagnosis is made mainly at autopsy as many of these patients experience sudden death when the main pulmonary artery dissects into the pericardium, causing acute cardiac tamponade. To our knowledge, five reported cases have described CT imaging findings of acute pulmonary artery dissection in the literature.