coffee bean sign

A classic finding in a patient with a sigmoid volvulus—the involved bowel wall is oedematous, and the contiguous walls form a dense white line on plain films of the abdomen. This line is surrounded by the curved and dilated gas-filled lumen, resulting in a coffee bean-shaped structure

coffee bean sign

A radiologic sign consisting of a greatly distended, air-filled loop of sigmoid colon extending from the pelvis on abdominal radiography. The apposed medial walls of the dilated bowel form a distinct oblique line that resembles the cleft of a coffee bean. The coffee bean arises from the pelvis and may be very large, with its apex often extending above the level of T10 to the left or right of the midline. This sign is characteristic of sigmoid volvulus.