apical cap

ap·i·cal cap

a curved shadow at the apex of one or both hemithoraces on chest x-ray; caused by pleural and pulmonary fibrosis or, on the left, by blood from a traumatic rupture of the aorta.

ap·i·cal cap

(ap'i-kăl kap) A curved shadow at the apex of one or both hemithoraces on chest x-ray; caused by pleural and pulmonary fibrosis.