notch sign of Rigler

notch sign of Rigler

A short, straight radiolucency seen by tomography, which penetrates a relatively well-circumscribed lung mass; the notch corresponds to the shadow of a feeder vessel that penetrates the mass.

First described as typical of malignancy, the notch sign is also seen in other conditions, such as granulomatous infections, and thus no longer considered to be of particular diagnostic utility.