Bowler hat sign

The bowler hat sign is a radiologic sign seen on double-contrasted barium enema studies, indicating the presence of a colonic polyp.[1] A ring of barium collects at the base of the polyp and also along its dome, simulating the appearance of a bowler hat.[1] This sign is present for growths that are an intermediate between flat and pedunculated.[2] The differential diagnosis for this sign includes bubbles, diverticula, and unusual projections of anatomic structures such as the appendix.[2]

References

  1. ^ a b Miller, W T; Levine, M S; Rubesin, S E; Laufer, I (1989). "Bowler-hat sign: a simple principle for differentiating polyps from diverticula". Radiology. 173 (3): 615–617. doi:10.1148/radiology.173.3.2813762. ISSN 0033-8419.
  2. ^ a b Simms, SM (1985). "Differential diagnosis of the bowler hat sign". American Journal of Roentgenology. 144 (3): 585–587. doi:10.2214/ajr.144.3.585. ISSN 0361-803X.