| Theme |
Autoimmune Pancreatitis |
| Title |
US, CT and MRI Findings of Autoimmune Pancreatitis |
| Author |
Hiroyuki Irie |
Department of Radiology, Faculty of Medicine, Saga University |
| Author |
Noriyuki Kamochi |
Department of Radiology, Faculty of Medicine, Saga University |
| Author |
Junichi Nojiri |
Department of Radiology, Faculty of Medicine, Saga University |
| Author |
Yoshiaki Egashira |
Department of Radiology, Faculty of Medicine, Saga University |
| Author |
Kouhei Sasaguri |
Department of Radiology, Faculty of Medicine, Saga University |
| Author |
Sho Kudo |
Department of Radiology, Faculty of Medicine, Saga University |
| [ Summary ] |
US, CT and MRI findings of autoimmune pancreatitis (AIP) are commented on based on the study titled, "Clinical diagnostic criteria of autoimmune pancreatitis 2006". Evaluation of pancreatic enlargement either diffuse or localized, is the essential evaluating point for imaging studies. However, other characteristic imaging findings are also required in order to obtain correct diagnoses. With US, hypoechoic pancreatic enlargement is observed to be characteristic of AIP, including a "sausage-like appearance". Dynamic studies, either with CTs, MRIs, or AIP usually exhibit delayed enhancement patterns. The signal intensity of T1-weighted MRIs is usually diminished, however, it varies in T2-weighted images. Attention should be paid to the fact that there are various imaging findings from AIP, probably due to various disease conditions. At present, MRCP cannot be used in evaluating main pancreatic duct narrowing, however, it may be used in the near feature with improvements in image quality. Differentiation between focal type AIP and pancreatic cancer is often difficult, although there are several differentiating points, such as the contours of the affected portion which is usually smooth. In addition, AIP does not obliterate peri-pancreatic fat tissue in contrast to pancreatic cancer. |