Reactive oxygen species (ROS) are believed to play an important role in the proinflammatory form of neuroinflammation. Therefore, the availability of a radiotracer labeled with a positron-emitting radionuclide that can measure levels of ROS in tissue could provide a valuable method for imaging neuroinflammation in vivo with the functional imaging technique positron emission tomography (PET). We previously reported the synthesis and in vivo evaluation of [F-18]ROStrace, a radiotracer for imaging ROS in vivo with PET, in an LPS model of neuroinflammation. In the current study, we conducted additional validation studies aimed at determining the cellular localization of this radiotracer in the same model. Our results indicate that [F-18]ROStrace is primarily localized in microglia/macrophages and neurons in LPS-treated animals, and provide further support in the use of this radiotracer as a PET-based probe for imaging the proinflammatory form of neuroinflammation. (C) 2019 Elsevier Inc. All rights reserved.