RT Journal Article SR Electronic T1 Total-Body 18F-FDG PET/CT in Autoimmune Inflammatory Arthritis at Ultra-Low Dose: Initial Observations JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1579 OP 1585 DO 10.2967/jnumed.121.263774 VO 63 IS 10 A1 Yasser Abdelhafez A1 Siba P. Raychaudhuri A1 Dario Mazza A1 Soumajyoti Sarkar A1 Heather L. Hunt A1 Kristin McBride A1 Mike Nguyen A1 Denise T. Caudle A1 Benjamin A. Spencer A1 Negar Omidvari A1 Heejung Bang A1 Simon R. Cherry A1 Lorenzo Nardo A1 Ramsey D. Badawi A1 Abhijit J. Chaudhari YR 2022 UL http://jnm.snmjournals.org/content/63/10/1579.abstract AB Autoimmune inflammatory arthritides (AIA), such as psoriatic arthritis and rheumatoid arthritis, are chronic systemic conditions that affect multiple joints of the body. Recently, total-body (TB) PET/CT scanners exhibiting superior technical characteristics (total-body coverage, geometric sensitivity) that could benefit AIA evaluation, compared with conventional PET/CT systems, have become available. The objectives of this work were to assess the performance of an ultra-low-dose, 18F-FDG TB PET/CT acquisition protocol for evaluating systemic joint involvement in AIA and to report the association of TB PET/CT measures with joint-by-joint rheumatologic examination and standardized rheumatologic outcome measures. Methods: Thirty participants (24 with AIA and 6 with osteoarthritis) were prospectively enrolled in this single-center, observational study. All participants underwent a TB PET/CT scan for 20 min starting at 40 min after intravenous injection of 78.1 ± 4.7 MBq of 18F-FDG. Qualitative and quantitative evaluation of 18F-FDG uptake and joint involvement were performed from the resulting images and compared with the rheumatologic assessments. Results: TB PET/CT enabled the visualization of 18F-FDG uptake at joints of the entire body, including those of the hands and feet, in a single bed position, and in the same phase of radiotracer uptake. A range of pathologies consistent with AIA (and non-AIA in the osteoarthritis group) were visualized, and the feasibility of extracting PET measures from joints examined by rheumatologic assessments was demonstrated. Of 1,997 evaluable joints, there was concordance between TB PET qualitative assessments and joint-by-joint rheumatologic evaluation in the AIA and non-AIA cohorts for 69.9% and 91.1% joints, respectively, and an additional 20.1% and 8.8% joints, respectively, deemed negative on rheumatologic examination showed PET positivity. On the other hand, 10.0% and 0% joints in the AIA and non-AIA cohorts, respectively, were positive on rheumatologic evaluation but negative on TB PET. Quantitative measures from TB PET in the AIA cohort demonstrated a moderate-to-strong correlation (Spearman ρ = 0.53–0.70, P < 0.05) with the rheumatologic outcome measures. Conclusion: Systemic joint evaluation in AIA (and non-AIA) is feasible with a TB PET/CT system and an ultra-low-dose protocol. Our results provide the foundation for future larger studies to evaluate the possible improvements in AIA joint assessment via the TB PET/CT technology.