Interesting Images68Ga–Prostate-Specific Membrane Antigen Focal Pulmonary Activity With No Corresponding CT AbnormalitySasikumar, Arun MD, FEBNM∗; Thampan, Sam MCh, FRCS†; Thomas, Nivya BSc, NM∗; Paul, Retcy BAMS∗Author Information From the ∗St Gregorios International Cancer Care Centre †Believers Church Medical College Hospital, Kerala, India. Received for publication May 15, 2020; revision accepted August 24, 2020. Conflicts of interest and sources of funding: none declared. Correspondence to: Arun Sasikumar, MD, FEBNM, Department of Nuclear Medicine, St Gregorios International Cancer Care Centre, Parumala, Pathanmthitta, Kerala, India. E-mail: [email protected]. Clinical Nuclear Medicine: February 2021 - Volume 46 - Issue 2 - p e88-e89 doi: 10.1097/RLU.0000000000003316 Buy Metrics Abstract We describe a case of 68Ga–prostate-specific membrane antigen PET/CT scan with focal tracer concentration in the lung without any abnormalities in the CT part. 18F-FDG focal uptake in lungs without corresponding CT lesions is described. Two possible mechanisms proposed to explain this finding in FDG PET/CT scans are iatrogenic pulmonary microembolism and 18F-FDG–avid infection or inflammation that precedes structural findings. Logically, these proposed mechanisms seem to be applicable to 68Ga–prostate-specific membrane antigen as well. In our case, there were no features of any lung infection/inflammation, and the most plausible explanation would be iatrogenic microembolism. Copyright © 2020 Wolters Kluwer Health, Inc. All rights reserved.