Interesting ImagesRecurrent Immunoglobulin G4–Related Disease Shown on 18F-FDG and 68Ga-FAPI PET/CTPan, Qingqing MD*,†; Luo, Yaping MD*,†; Zhang, Wen MD‡Author Information From the *Department of Nuclear Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College Hospital †Beijing Key Laboratory of Molecular Targeted Diagnosis and Therapy in Nuclear Medicine ‡Department of Rheumatology, Chinese Academy of Medical Sciences and Peking Union Medical College Hospital, Beijing, People’s Republic of China. Received for publication October 15, 2019; revision accepted November 5, 2019. Conflicts of interest and sources of funding: This work is supported by the CAMS Initiative for Innovative Medicine (CAMSI2M, 2017-I2M-3-001). None declared to all authors. Correspondence to: Yaping Luo, MD, Department of Nuclear Medicine, Chinese Academy of Medical Sciences and Peking Union Medical College Hospital, Wangfujing, Dongcheng District, Beijing 100730, People’s Republic of China. E-mail: firstname.lastname@example.org. Online date: January 30, 2020 Clinical Nuclear Medicine: April 2020 - Volume 45 - Issue 4 - p 312-313 doi: 10.1097/RLU.0000000000002919 Buy Metrics Abstract A 21-year-old man had been diagnosed with immunoglobulin G4–related disease (IgG4-RD) for 5 years, and the disease recurred 1 month ago. 18F-FDG PET/CT revealed intense FDG activity in the pituitary stalk, submandibular gland, pleura, pericardium, pancreas, liver, prostate, and multiple lymph nodes, which were considered the involvements of IgG4-RD. 68Ga-FAPI PET/CT also showed intense 68Ga-FAPI uptake in the above FDG-avid lesions except the lymph node involvement. Additionally, involvement in the lacrimal glands was detected by 68Ga-FAPI. The positive findings of 68Ga-FAPI in the current case highlighted that 68Ga-FAPI may have value in the evaluation of IgG4-RD. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.