Spectrum of IgG4-related disease on multi-detector CT: a 5-year study of a single medical center data.

To discuss the diverse imaging features of pancreatic and extra-pancreatic lesions of IgG4-related disease (IgG4-RD) on multi-detector CT (MDCT). This retrospective study was approved by our institutional research ethics board, and informed consent was waived. From 2008 to 2013, 159 patients including 120 men (mean age 57 years; range 27-79 years) and 39 women (mean age 51 years; range 25-83 years) who met the comprehensive diagnostic criteria for IgG4-RD (2011) were enrolled. MDCT images consisted of 153 abdominal images, 64 pelvic images, 64 thoracic images, and 8 neck images were retrospectively analyzed in consensus by two radiologists with expertise in the CT diagnosis of IgG4-RD. Only 11 (11/153, 7.2%) IgG4-RD patients had been found with no pancreatic involvement. 145 (145/159, 91.2%) patients had various extra-pancreatic lesions, including involvement of biliary tree (93/153, 60.8%), peri-pancreatic vessels (66/153, 43.1%), IgG4-related lymphadenopathy, peri-abdominal aorta arteritis or retroperitoneal fibrosis, head and neck lesions, etc. Renal lesions were found in 26 (26/153, 17.0%) IgG4-RD patients with 4 types of renal parenchymal involvement. Lung lesions were found in 44 (44/64, 68.7%) IgG4-RD patients, which were classified into 7 types. Pancreatic and various extra-pancreatic lesions may be involved in IgG4-RD patients frequently with typical imaging findings. It is useful to recognize the atypical or uncommon imaging features to help the diagnosis of IgG4-RD together with other serologic or histopathologic findings.