[Clinical significance of the enlargement of the descending pulmonary artery in pulmonary embolism].

The authors reviewed chest radiographs of 158 patients with clinical suspicion of pulmonary embolism, subsequently confirmed in 73 and excluded in 85. Right descending pulmonary artery, measured at 4 different levels, was significantly enlarged at acute embolization in respect to either the diameter showed at recovery and the upper normal limit reported in literature. Moreover, the artery was significantly wider in embolic than in non embolic patients. In addition, the shape of this artery was modified in embolism, since the prevailing enlargement of its upper sections caused the artery to take a truncated cone appearance. "Sausage" appearance of the artery, never found in non embolic patients, was specific for embolism. The radiographic width of the descending pulmonary artery enabled also to identify patients most seriously ill, since it showed a positive linear correlation with the degree of perfusion impairment.