title: (18)F-FDG and (18)F-NaF PET/CT demonstrate coupling of inflammation and accelerated bone turnover in rheumatoid arthritis.
abstract: OBJECTIVE
  To compare the findings in rheumatoid arthritis (RA)-affected joints between (18)F-fluorodeoxyglucose (FDG) and (18)F-fluoride (NaF) positron emission tomography (PET)/computed tomography (CT).
  
  
  METHODS
  We enrolled twelve RA patients who started a new biologic agent (naïve 9 and switch 3). At entry, both hands were examined by (18)F-FDG PET/CT, (18)F-NaF PET/CT, and X-ray. Intensity of PET signals was determined by standardized uptake value max (SUVmax) in metacarpophalangeal (MCP), proximal interphalangeal (PIP), and ulnar, medial, and radial regions of the wrists. Hand X-rays were evaluated according to the Genant-modified Sharp score at baseline and 6 months.
  
  
  RESULTS
  Both (18)F-FDG and (18)F-NaF accumulated in RA-affected joints. The SUVmax of (18)F-FDG correlated with that of (18)F-NaF in individual joints (r = 0.65), though detail distribution was different between two tracers. (18)F-NaF and (18)F-FDG signals were mainly located in the bone and the surrounding soft tissues, respectively. The sum of SUVmax of (18)F-NaF correlated with disease activity score in 28 joint (DAS28), modified health assessment questionnaire (MHAQ), and radiographic progression. (18)F-FDG and (18)F-NaF signals were associated with the presence of erosions, particularly progressive ones.
  
  
  CONCLUSIONS
  Our data show that both (18)F-FDG and (18)F-NaF PET signals were associated with RA-affected joints, especially those with ongoing erosive changes.
authors.affiliation: a Center for Rheumatic disease, Yokohama City University Medical Center , Yokohama , Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Kaoru
authors.initials: K
authors.lastname: Takase-Minegishi
authors.affiliation: c Department of Rheumatology and Infectious disease , Yokohama Minami Kyosai Hospital , Yokohama , Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ihata
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Kunishita
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Daiga
authors.initials: D
authors.lastname: Kishimoto
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Reikou
authors.initials: R
authors.lastname: Kamiyama
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Maasa
authors.initials: M
authors.lastname: Hama
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Ryusuke
authors.initials: R
authors.lastname: Yoshimi
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Yohei
authors.initials: Y
authors.lastname: Kirino
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Asami
authors.affiliation: a Center for Rheumatic disease, Yokohama City University Medical Center , Yokohama , Japan.
authors.forename: Akiko
authors.initials: A
authors.lastname: Suda
authors.affiliation: a Center for Rheumatic disease, Yokohama City University Medical Center , Yokohama , Japan.
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ohno
authors.affiliation: d Department of Radiology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Atsuhisa
authors.initials: A
authors.lastname: Ueda
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Takeno
authors.affiliation: b Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Ishigatsubo
mesh_terms: D000328:Adult; D000368:Aged; D018501:Antirheumatic Agents / Q000627:therapeutic use; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging* / Q000188:drug therapy; D016723:Bone Remodeling / Q000502:physiology*; D018450:Disease Progression; D005260:Female; D019788:Fluorodeoxyglucose F18; D050823:Hand Joints / Q000000981:diagnostic imaging*; D006801:Humans; D007249:Inflammation / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D014057:Tomography, X-Ray Computed; D014955:Wrist Joint / Q000000981:diagnostic imaging*
chemical_list: D018501:Antirheumatic Agents; D019788:Fluorodeoxyglucose F18
keywords: 18F-FDG PET; 18F-NaF PET; Bone turnover; Rheumatoid arthritis