Diffuse FDG uptake in the bilateral lungs: hypersensitivity pneumonitis supported by low-dose CT findings

Shun Goto; Yohji Matsusaka; Tomohiko Yamane; Yuki Hoshino; Ichiei Kuji

doi:10.22038/AOJNMB.2021.56000.1393

Diffuse FDG uptake in the bilateral lungs: hypersensitivity pneumonitis supported by low-dose CT findings

Asia Ocean J Nucl Med Biol. 2022 Winter;10(1):43-46. doi: 10.22038/AOJNMB.2021.56000.1393.

Authors

Shun Goto¹, Yohji Matsusaka¹, Tomohiko Yamane¹, Yuki Hoshino², Ichiei Kuji¹

Affiliations

¹ Department of Nuclear Medicine, Saitama Medical University International Medical Center, Saitama, Japan.
² Department of Respiratory Medicine, Saitama Medical University Hospital, Saitama, Japan.

Abstract

Hypersensitivity pneumonitis (HP) is an interstitial lung disease resulting from an immune-mediated response in susceptible and sensitized individuals to various inhaled antigens in the environment. Imaging diagnosis is usually based on high-resolution CT findings. Here, we present a 49-year-old man with a history of diffuse large B-cell lymphoma presented with fever and occasional cough. ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) revealed diffuse FDG uptake in the bilateral lungs. Expiratory low-dose CT simultaneously performed in PET scanning revealed centrilobular nodules and air trapping in ground glass opacities (GGO). Our imaging diagnosis was acute hypersensitivity pneumonitis (HP). Based on the results of his clinical course, blood laboratory tests, and bronchoscopy, he was diagnosed with acute HP. Diffuse pulmonary FDG uptake can be seen in the patients with acute HP. In addition, expiratory low-dose CT findings of centrilobular nodules and air trapping in GGO may be helpful for accurate diagnosis of acute HP.

Keywords: 18F-fluorodeoxyglucose; Hypersensitivity pneumonitis; Low-dose computed tomography; Positron emission tomography.

Publication types

Case Reports