title: Utility of FDG-PET/CT in the diagnosis of IgG4-related diseases.
abstract: OBJECTIVE
  The purpose of this work is to evaluate the usefulness of 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) imaging in management of IgG4-related disease (IgG4-RD) by retrospective analysis of PET/CT results in IgG4-RD patients.
  
  
  METHODS
  Twenty-six patients diagnosed with IgG4-RD according to Japanese diagnostic criteria who underwent 18F-FDG-PET/CT scans in the PLA General Hospital from January 2010 to May 2015 were enrolled in the study. Their clinical presentations and 18F-FDG-PET/CT findings were analysed.
  
  
  RESULTS
  A total of 26 patients (20 men; 6 women) with a mean age of 53.8 years (range 35-71 years) and mean treatment course of 7.1 months (range 0.33-72 months) who underwent 18F-FDG-PET/CT scans were analysed. CRP was relatively low in all patients (mean 0.79 mg/dl). 18F-FDG-PET/CT images confirmed that two or more organs were involved in all patients, and average SUV values for involved organs was 4.14 (range 0.30-8.78). Eleven patients were misdiagnosed with submandibular tumours, pancreatic cancer, pancreatitis, pulmonary interstitial fibrosis, retroperitoneal fibrosis or systemic vasculitis prior to 18F-FDG-PET/CT imaging.
  
  
  CONCLUSIONS
  18F-FDG-PET/CT imaging is a useful tool for the differential diagnosis of IgG4-RD, and for mapping involved organs, guiding biopsy, and monitoring treatment response.
authors: Department of Rheumatology, PLA General Hospital, Beijing, China.
authors: Zheng
authors: Z
authors: Zhao
authors: Department of Rheumatology, PLA General Hospital, Beijing, China.
authors: Yanyan
authors: Y
authors: Wang
authors: Department of Nuclear Medicine, PLA General Hospital, Beijing, China.
authors: Zhiwei
authors: Z
authors: Guan
authors: Department of Rheumatology, PLA General Hospital, Beijing, China.
authors: Jingyu
authors: J
authors: Jin
authors: Department of Rheumatology, PLA General Hospital, Beijing, China.
authors: Feng
authors: F
authors: Huang
authors: Department of Rheumatology, PLA General Hospital, Beijing, China. jian_jzhu@126.com.
authors: Jian
authors: J
authors: Zhu
mesh_terms: D000328:Adult; D000368:Aged; D001327:Autoimmune Diseases / Q000000981:diagnostic imaging* / Q000276:immunology / Q000628:therapy; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D007074:Immunoglobulin G; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18