Kerley’s A lines (arrows) are linear opacities extending from the periphery to the hila; they are caused by distention of anastomotic channels between peripheral and central lymphatics.
Kerley’s B lines (white arrowheads) are short horizontal lines situated perpendicularly to the pleural surface at the lung base; they represent edema of the interlobular septa.
Kerley’s C lines (black arrowheads) are reticular opacities at the lung base, representing Kerley’s B lines en face.
These radiologic signs and physical findings suggest cardiogenic pulmonary edema.
