Original ArticleF-18 FDG Whole-Body PET for the Assessment of Disease Activity in Patients With Rheumatoid ArthritisGoerres, Gerhard W. MD*; Forster, Adrian MD†; Uebelhart, Daniel MD†‡; Seifert, Burkhardt PhD§; Treyer, Valerie PhD∥; Michel, Beat MD†‡; von Schulthess, Gustav K. MD, PhD∥; Kaim, Achim H. MD¶Author Information From the *Institute of Diagnostic Radiology, Department of Medical Radiology, the †Department of Rheumatology and Institute of Physical Medicine, the ‡Osteoporosis Center, the §Department of Biostatistics, and ∥Nuclear Medicine, University Hospital Zurich, Zurich, Switzerland; and ¶Klinik im Schachen, Aarau, Switzerland. Received for publication June 5, 2005; revision accepted January 23, 2006. Reprints: Gerhard W. Goerres, MD, Institute of Diagnostic Radiology, Department of Medical Radiology, University Hospital Zurich, Raemistr. 100, CH-8091 Zurich, Switzerland. E-mail: [email protected]. Clinical Nuclear Medicine: July 2006 - Volume 31 - Issue 7 - p 386-390 doi: 10.1097/01.rlu.0000222678.95218.42 Buy Metrics Abstract Purpose of Report: F-18 fluorodeoxyglucose (FDG) positron emission tomography (PET) can be used to image synovitis in patients with rheumatoid arthritis (RA). The aim of this study was to evaluate if a simple scoring system based on visual assessment of FDG joint uptake correlates with the clinical assessment of patients with RA undergoing antiinflammatory treatment. Materials and Methods: Seven patients with active RA underwent whole-body FDG PET and clinical assessment before and after treatment with the antitumor necrosis factor alpha antibody (infliximab). A PET total joint score, ie, the sum of all scores based on FDG uptake intensity between zero and 4 in 28 joints, was correlated with a total joint score based on the clinical disease activity in the same joints using a Spearman rank correlation. Results: The PET based total joint score was similarly high before onset as was the clinical total joint score. The decrease of FDG joint uptake in the follow-up PET scans correlated significantly with the clinical assessment. Additionally, synovial FDG uptake was found in extraarticular sites such as tendon sheaths and bursae. Conclusions: Visual assessment of FDG uptake shows a significant correlation with clinical evaluation of disease activity in patients with RA undergoing antiinflammatory treatment. © 2006 Lippincott Williams & Wilkins, Inc.