title: Similarities and differences in fluorodeoxyglucose positron emission tomography/computed tomography findings in spondyloarthropathy, polymyalgia rheumatica and rheumatoid arthritis.
abstract: OBJECTIVE
  We assessed fluorine-18 ((18)F)-labelled fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) findings in patients with seronegative spondyloarthritis (SpA), polymyalgia rheumatica (PMR), and rheumatoid arthritis (RA).
  
  
  METHODS
  We studied 53 patients with SpA (n=21), PMR (n=16), or RA (n=16) admitted to our hospital between 2006 and 2011. Disease activity in the ischial tuberosities, greater trochanters, spinous processes, vertebral bodies, and sacroiliac joints (SIJ) were evaluated by determining FDG accumulation using maximum standardized uptake values (SUV(max)) and FDG scores.
  
  
  RESULTS
  SUV(max) for ischial tuberosities was significantly higher in PMR than SpA or RA. SUV(max) for greater trochanters and spinous processes was significantly higher in PMR than RA (P<0.001) and significantly higher in SpA than in PMR or RA for SIJ (P=0.01). No significant difference in vertebral scores was observed among groups (P=0.488). FDG scores yielded similar results. X-ray findings were consistent with PET/CT findings in 3/15 (20%) patients with sacroiliitis, whereas magnetic resonance imaging findings were consistent with PET/CT findings in 4/7 (57.1%) patients.
  
  
  CONCLUSIONS
  PET/CT detection of inflammation in the ischial tuberosities, greater trochanters, and spinous processes discriminated between PMR and RA, but not between SpA and PMR. PET/CT findings can distinguish SpA from RA and PMR and are useful for the early diagnosis of sacroiliitis.
authors: Division of Rheumatic Diseases, National Center for Global Health and Medicine, 1-21-1 Toyama, Shinjuku-ku, Tokyo, 162-8655, Japan. hiroyuki_yjp2005@yahoo.co.jp
authors: Hiroyuki
authors: H
authors: Yamashita
authors: Kazuo
authors: K
authors: Kubota
authors: Yuko
authors: Y
authors: Takahashi
authors: Ryogo
authors: R
authors: Minamimoto
authors: Miyako
authors: M
authors: Morooka
authors: Hiroshi
authors: H
authors: Kaneko
authors: Toshikazu
authors: T
authors: Kano
authors: Akio
authors: A
authors: Mimori
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001172:Arthritis, Rheumatoid / Q000000981:diagnostic imaging*; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D007596:Joints / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D015999:Multivariate Analysis; D011111:Polymyalgia Rheumatica / Q000000981:diagnostic imaging*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D025242:Spondylarthropathies / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18