title: Deep-inspiration breath-hold 18F-FDG-PET/CT is useful for assessment of connective tissue disease associated interstitial pneumonia.
abstract: OBJECTIVE
  To examine clinical utility of (18)F-flurodeoxyglucose (FDG)-positron emission tomography (PET)/CT for assessment of interstitial lung disease (ILD) in patients with connective tissue diseases (CTDs).
  
  
  METHODS
  A total of 69 (18)F-FDG PET/CT scans were conducted under deep inspiratory breath hold (DIBH) conditions in 45 CTD patients with ILD, including 16 dermatomyositis/polymyositis, nine systemic scleroderma and seven rheumatoid arthritis. Intensity and distribution of (18)F-FDG signals in PET/CT were determined by standardized uptake value (SUVmax) and visual score in 18 regions, respectively. ILD was defined as active when immunosuppressive therapy was initiated or intensified.
  
  
  RESULTS
  Both SUVmax and visual score were higher in active phase (n = 32) than inactive phase (n = 37) (both p < 0.05), regardless of the underlying CTD and plain CT findings. The both parameters reduced after initiating or intensifying treatment in the follow-up study of 17 active patients except two died patients who showed increased visual score. Another two died patients showed high visual score (15 and 6/18, respectively). Changing ratio of visual score, but not SUVmax was correlated with KL-6 (r(2) = 0.38, p < 0.05) and CRP (r(2) = 0.52, p < 0.05).
  
  
  CONCLUSIONS
  The DIBH (18)F-FDG PET/CT procedure sensitively illustrates active ILD lesions in CTD and the extended signal distribution is associated with unfavorable clinical outcome.
authors.affiliation: a Department of Internal Medicine and Clinical Immunology , Yokohama City University Graduate School of Medicine , Yokohama , Japan .
authors.forename: Takeaki
authors.initials: T
authors.lastname: Uehara
authors.affiliation: a 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: a 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: a 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 Center for Rheumatic Diseases, Yokohama City University Medical Center , Yokohama , Japan .
authors.forename: Akiko
authors.initials: A
authors.lastname: Suda
authors.affiliation: c Department of Rheumatology and Infectious Disease , Yokohama Minami Kyosai Hospital , Yokohama , Japan , and.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Ihata
authors.affiliation: a 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: d Department of Radiology , Graduate School of Medicine, Yokohama City University , Yokohama , Japan.
authors.forename: Ukihide
authors.initials: U
authors.lastname: Tateishi
authors.affiliation: a 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; D000369:Aged, 80 and over; D062485:Breath Holding; D003240:Connective Tissue Diseases / Q000150:complications*; D003952:Diagnostic Imaging / Q000379:methods*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D017563:Lung Diseases, Interstitial / Q000175:diagnosis* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Connective tissue disease; DIBH-FDG PET/CT; Dermatomyositis; Interstitial lung disease