title: Positron emission tomography/computed tomography: a clinical tool for evaluation of enthesitis in patients with spondyloarthritides.
abstract: OBJECTIVE
  To evaluate the accuracy of PET/CT using [(18)F]fluorodeoxyglucose (FDG) in determining the presence of enthesitis in patients with SpAs.
  
  
  METHODS
  Results of PET/CT scans of eight patients with SpA and seven patients with RA were retrospectively examined, with specific focus on five joints and three entheses. Volume fixation values are expressed as standardized uptake values (SUVs). Data from 20 patients with non-rheumatic (NR) diseases and 20 healthy subjects were also examined if non-specific, false positive findings were possible. We evaluated the clinical utility of PET/CT examinations in SpA, compared with MRI and Ga scintigraphy.
  
  
  RESULTS
  Images of PET/CT scans of the shoulder, hip and knee joints revealed that FDG accumulated at the entheses in SpA and in the synovium in RA patients. The maximum SUVs [mean (s.d.)] were statistically higher in SpA patients compared with RA patients at the entheses of lumbar spinous process [4.83 (1.15) vs 1.42 (0.34); P < 0.05, respectively], pubic symphysis [3.93 (0.87) vs 1.35 (0.31); P < 0.05, respectively] and ischial tuberosity [4.76 (1.5) vs 1.35 (0.42); P < 0.05, respectively]. The positive frequencies of lumbar spinous processes and ischial tuberosity evaluated by PET/CT scan in the SpA group were significantly higher than that evaluated by MRI.
  
  
  CONCLUSIONS
  MRI is now widely used to detect bone marrow oedema and enthesitis in patients with SpA. PET/CT scans offer an alternative method to identify enthesitis, and will likely contribute to the early diagnosis of SpA.
authors.affiliation: Department of Endocrinology, Metabolism and Nephrology, Kochi Medical School, Kochi University, Kochi, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Taniguchi
authors.forename: Kaoru
authors.initials: K
authors.lastname: Arii
authors.forename: Yoshitaka
authors.initials: Y
authors.lastname: Kumon
authors.forename: Mitsutaka
authors.initials: M
authors.lastname: Fukumoto
authors.forename: Takenao
authors.initials: T
authors.lastname: Ohnishi
authors.forename: Taro
authors.initials: T
authors.lastname: Horino
authors.forename: Toru
authors.initials: T
authors.lastname: Kagawa
authors.forename: Shigeto
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Yoshio
authors.initials: Y
authors.lastname: Terada
mesh_terms: D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D025241:Spondylarthritis / Q000150:complications*; D052256:Tendinopathy / Q000175:diagnosis* / Q000209:etiology*; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18