Fleischner sign: prominent dilated central pulmonary artery. Enlargement can be associated with massive embolus enlarging the luminal diameter of the proximal artery in the acute setting; or pulmonary hypertension in the subacute to chronic setting
Palla sign (1983) right descending pulmonary artery enlargement and 'sausage-shaped' appearance as a potential sign of pulmonary embolism on chest XR
Chang sign (1965) Dilated descending pulmonary artery associated with pulmonary infarction and pulmonary hypertension following pulmonary embolism
Antonio Palla (1949 - ) is an Italian respiratory and nuclear medicine specialist. Palla sign in pulmonary embolus (1983)
C. H. Joseph Chang (1929 - 2017) was an American radiologist. Chang sign (CXR finding in pulmonary embolus) decribed in 1965