Rigler notch sign (lungs)

The Rigler notch sign refers to an indentation in the border of a solid lung mass, which is thought to represents a feeding vessel, thus suggesting the presence of a bronchial carcinoma . However, this sign is also observed in other conditions, including granulomatous infections, and its differentiating utility is therefore limited.
History and etymology
It is named after Leo George Rigler (1896-1979), American radiologist .
Practical points
The Rigler notch sign should not be confused with the Rigler sign on an abdominal radiograph, which is indicative of a pneumoperitoneum, or Rigler triad or Hoffman-Rigler sign.
