Frostberg inverted 3 sign is a radiological sign seen on a barium examination where there is effacement and distortion of the mucosal pattern on the medial wall of the second part of the duodenum due to focal mass and local oedema. It is most commonly associated with carcinoma of the head of the pancreas but can also be seen in duodenal carcinoma and pancreatitis.
History and etymology
The sign was named after Dr Nils Frostberg ,a Swedish radiologist, who described it in a 1938 paper 1.
- 1. Frostberg N (1938) A characteristic duodenal deformity in cases of different kinds of peri-Vaterial enlargement of the pancreas, Acta Radiologica. 1938;19:164-173. DOI: 10.3109/00016923809137754