State of the art of 18F-FDG PET/CT application in inflammation and infection: a guide for image acquisition and interpretation

Abstract

Aim The diagnosis, severity and extent of a sterile inflammation or a septic infection could be challenging since there is not one single test able to achieve an accurate diagnosis. The clinical use of 18F-fluorodeoxyglucose ([ 18 F]FDG) positron emission tomography/computed tomography (PET/CT) imaging in the assessment of inflammation and infection is increasing worldwide. The purpose of this paper is to achieve an Italian consensus document on [ 18 F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases, such as osteomyelitis (OM), prosthetic joint infections (PJI), infective endocarditis (IE), prosthetic valve endocarditis (PVE), cardiac implantable electronic device infections (CIEDI), systemic and cardiac sarcoidosis (SS/CS), diabetic foot (DF), fungal infections (FI), tuberculosis (TBC), fever and inflammation of unknown origin (FUO/IUO), pediatric infections (PI), inflammatory bowel diseases (IBD), spine infections (SI), vascular graft infections (VGI), large vessel vasculitis (LVV), retroperitoneal fibrosis (RF) and COVID-19 infections. Methods In September 2020, the inflammatory and infectious diseases focus group (IIFG) of the Italian Association of Nuclear Medicine (AIMN) proposed to realize a procedural paper about the clinical applications of [ 18 F]FDG PET/CT or PET/MRI in inflammatory and infectious diseases. The project was carried out thanks to the collaboration of 13 Italian nuclear medicine centers, with a consolidate experience in this field. With the endorsement of AIMN, IIFG contacted each center, and the pediatric diseases focus group (PDFC). IIFG provided for each team involved, a draft with essential information regarding the execution of [ 18 F]FDG PET/CT or PET/MRI scan (i.e., indications, patient preparation, standard or specific acquisition modalities, interpretation criteria, reporting methods, pitfalls and artifacts), by limiting the literature research to the last 20 years. Moreover, some clinical cases were required from each center, to underline the teaching points. Time for the collection of each report was from October to December 2020. Results Overall, we summarized 291 scientific papers and guidelines published between 1998 and 2021. Papers were divided in several sub-topics and summarized in the following paragraphs: clinical indications, image interpretation criteria, future perspectivess and new trends (for each single disease), while patient preparation, image acquisition, possible pitfalls and

Diagnostic performance of 18F‐FDG‐PET/CT in inflammation of unknown origin: A clinical series of 317 patients

“…Internists manage a wide variety of clinical issues, including fever of unknown origin (FUO) and inflammation of unknown origin (IUO). 18 F‐fluorodesoxyglucose positron emission tomography with computerized tomography ( 18 F‐FDG‐PET/CT) appears to be a high‐performance [1,2] and cost‐effective tool for diagnosing FUO [3]. IUO is defined as a prolonged and unexplained inflammatory syndrome for which final diagnoses are heterogeneous [4–6].…”

“…is defined as a prolonged and unexplained inflammatory syndrome for which final diagnoses are heterogeneous [4][5][6]. Currently, 18 F-FDG-PET/CT is widely used in the diagnosis strategy for investigating IUO, but it is not yet clearly validated [3,5,6].…”

Comparison of L- and D-Amino Acids for Bacterial Imaging in Lung Infection Mouse Model

“…In the biological distribution of 18 F-FDG, significant differences between the control mice and the mice at 4 h after infection were found in the lung and spleen at 15 min after 18 F-FDG administration ( Table 3 ). 18 F-FDG accumulation is reported to indicate areas of inflammation after infection, as well as bacterial infection [ 25 ]. The 18 F-FDG results of the present study suggested minimal areas of inflammation in the whole body because the accumulation of 18 F-FDG at 4 h after infection was not significantly different to that in controls, except in the brain and spleen.…”

Highlights of the Latest Developments in Radiopharmaceuticals for Infection Imaging and Future Perspectives

“…The urgency of imaging patients acutely ill with COVID-19 as well as following up post-COVID patients and those receiving vaccines, did not allow for time to create SARS-CoV-2 specific imaging agents. The domineering modality so far has been FDG-PET/CT covered in several excellent reviews (55,56) while SPECT imaging also contributes, for example, toward imaging of pulmonary emboli in COVID patients (57). As COVID-19 will gradually become endemic, it is only a matter of time when COVID-specific PET and SPECT imaging agents are developed.…”