Frostburg's reverse 3 sign is seen in –: (A) Periampullary carcinoma, (B) Annular pancreatic carcinoma, (C) Carcinoma head of pancreas, (D) All
Answer is C. Reversed '3' sign of frost berg  → Carcinoma head of pancreas.
Double duct sign → Periampullary carcinoma.
"Beaded appearance" of biliary ducts → Primary sclerosing cholangitis.