OBJECTIVE: To determine reliable MRI features of autoimmune pancreatitis (AIP) in the proximal pancreas that could allow its differentiation from pancreatic ductal adenocarcinoma (PDAC). METHODS: Twenty-three patients with AIP and 61 patients with PDAC in the proximal pancreas underwent MRI. Two observers analyzed MRI for lesion morphology, hypointensity degree on T1-weighted images, enhancement pattern during dynamic phases, capsule-like rim, presence of cysts and duct penetrating sign, morphology of bile duct, and icicle appearance and tortuosity of the upstream pancreatic duct. Sensitivity and specificity for the diagnosis of AIP were calculated for each category or combined. RESULTS: When isointensity on the portal and late phase of MRI and/or the icicle sign of pancreatic duct are applied, 100 % sensitivity for the diagnosis of AIP in the proximal pancreas was achieved. Applying both mild T1 hypointensity similar to the spleen and the icicle sign enabled 100 % specificity for the diagnosis of AIP by differentiating it from PDAC. CONCLUSION: The combination of the icicle sign in the upstream pancreatic duct and mild T1 hypointensity or isointensity on portal and late phase of dynamic MRI could be reliable MR features for the diagnosis of AIP in the proximal pancreas by allowing its differentiation from PDAC. KEY POINTS: • The icicle sign of the pancreatic duct is useful for diagnosing AIP. • Mild T1 hypointensity similar to the spleen is useful for diagnosing AIP. • Isointensity on portal and late phases MRI is useful for diagnosing AIP.
OBJECTIVE: To determine reliable MRI features of autoimmune pancreatitis (AIP) in the proximal pancreas that could allow its differentiation from pancreatic ductal adenocarcinoma (PDAC). METHODS: Twenty-three patients with AIP and 61 patients with PDAC in the proximal pancreas underwent MRI. Two observers analyzed MRI for lesion morphology, hypointensity degree on T1-weighted images, enhancement pattern during dynamic phases, capsule-like rim, presence of cysts and duct penetrating sign, morphology of bile duct, and icicle appearance and tortuosity of the upstream pancreatic duct. Sensitivity and specificity for the diagnosis of AIP were calculated for each category or combined. RESULTS: When isointensity on the portal and late phase of MRI and/or the icicle sign of pancreatic duct are applied, 100 % sensitivity for the diagnosis of AIP in the proximal pancreas was achieved. Applying both mild T1 hypointensity similar to the spleen and the icicle sign enabled 100 % specificity for the diagnosis of AIP by differentiating it from PDAC. CONCLUSION: The combination of the icicle sign in the upstream pancreatic duct and mild T1 hypointensity or isointensity on portal and late phase of dynamic MRI could be reliable MR features for the diagnosis of AIP in the proximal pancreas by allowing its differentiation from PDAC. KEY POINTS: • The icicle sign of the pancreatic duct is useful for diagnosing AIP. • Mild T1 hypointensity similar to the spleen is useful for diagnosing AIP. • Isointensity on portal and late phases MRI is useful for diagnosing AIP.
Authors: Max G Bachem; Marion Schünemann; Marco Ramadani; Marco Siech; Hans Beger; Andreas Buck; Shaoxia Zhou; Alexandra Schmid-Kotsas; Guido Adler Journal: Gastroenterology Date: 2005-04 Impact factor: 22.682
Authors: Suresh T Chari; Thomas C Smyrk; Michael J Levy; Mark D Topazian; Naoki Takahashi; Lizhi Zhang; Jonathan E Clain; Randall K Pearson; Bret T Petersen; Santhi Swaroop Vege; Michael B Farnell Journal: Clin Gastroenterol Hepatol Date: 2006-07-14 Impact factor: 11.382
Authors: Young Jun Choi; Jae Ho Byun; Ji-Youn Kim; Myung-Hwan Kim; Se Jin Jang; Hyun Kwon Ha; Moon-Gyu Lee Journal: Eur J Radiol Date: 2007-09-04 Impact factor: 3.528
Authors: Timothy B Gardner; Michael J Levy; Naoki Takahashi; Thomas C Smyrk; Suresh T Chari Journal: Am J Gastroenterol Date: 2009-07 Impact factor: 10.864
Authors: J-Matthias Löhr; Ulrich Beuers; Miroslav Vujasinovic; Domenico Alvaro; Jens Brøndum Frøkjær; Frank Buttgereit; Gabriele Capurso; Emma L Culver; Enrique de-Madaria; Emanuel Della-Torre; Sönke Detlefsen; Enrique Dominguez-Muñoz; Piotr Czubkowski; Nils Ewald; Luca Frulloni; Natalya Gubergrits; Deniz Guney Duman; Thilo Hackert; Julio Iglesias-Garcia; Nikolaos Kartalis; Andrea Laghi; Frank Lammert; Fredrik Lindgren; Alexey Okhlobystin; Grzegorz Oracz; Andrea Parniczky; Raffaella Maria Pozzi Mucelli; Vinciane Rebours; Jonas Rosendahl; Nicolas Schleinitz; Alexander Schneider; Eric Fh van Bommel; Caroline Sophie Verbeke; Marie Pierre Vullierme; Heiko Witt Journal: United European Gastroenterol J Date: 2020-06-18 Impact factor: 4.623