Palla's sign

Palla's sign is a clinical sign in which an enlarged right descending pulmonary artery is seen on the chest x-ray in patients with pulmonary embolism. It is of low sensitivity, and its specificity is not known. It exhibits as a 'sausage' appearance on X-ray. Palla's sign is a clinical sign in which an enlarged right descending pulmonary artery is seen on the chest x-ray in patients with pulmonary embolism. It is of low sensitivity, and its specificity is not known. It exhibits as a 'sausage' appearance on X-ray.