title: Role of FDG PET-CT in Takayasu arteritis: sensitive detection of recurrences.
abstract: OBJECTIVE
  The aim of this study was to investigate whether the maximum standardized uptake value (max SUV) of (18)F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) provides a quantitative indication of disease activity in Takayasu arteritis (TA) cases.
  
  
  BACKGROUND
  The clinical value of FDG-PET for assessing TA has been investigated. Clinical evaluation of disease activity is often difficult, because most patients develop recurrent inflammation while receiving corticosteroid treatment.
  
  
  METHODS
  Thirty-nine TA patients underwent FDG-PET/CT at Tokyo Medical and Dental University from 2006 to 2010 (35 women and 4 men; median age, 30 years). Disease activity was defined according to National Institutes of Health criteria. Biomarkers including C-reactive protein and erythrocyte sedimentation rate were measured. Forty subjects without vasculitis served as control subjects.
  
  
  RESULTS
  The max SUV was significantly higher in active than in inactive cases and control subjects (active [n = 27], median value, 2.7 vs. inactive [n = 12], 1.9; control [n = 40], 1.8; p < 0.001 each). Given a max SUV cutoff of 2.1, sensitivity for active-phase TA was 92.6%, specificity 91.7%, positive predictive value 96.2%, and negative predictive value 84.6%. In receiver-operating characteristic curves comparison, max SUV was superior to C-reactive protein (p < 0.05) and erythrocyte sedimentation rate (p < 0.05). Max SUV was significantly higher in relapsing on treatment cases (n = 17) than in stable on treatment cases (n = 12) (median value, 2.6 vs. 1.9; p < 0.001).
  
  
  CONCLUSIONS
  FDG-PET/CT is useful for detection of active inflammation not only in patients with active TA before treatment but also in relapsing patients receiving immunosuppressive agents. The max SUV is useful for assessing subtle activity of TA with high sensitivity.
authors.affiliation: Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Tokyo, Japan.
authors.forename: Daisuke
authors.initials: D
authors.lastname: Tezuka
authors.forename: Go
authors.initials: G
authors.lastname: Haraguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishihara
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Ohigashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Suzuki
authors.forename: Kenzo
authors.initials: K
authors.lastname: Hirao
authors.forename: Mitsuaki
authors.initials: M
authors.lastname: Isobe
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D005500:Follow-Up Studies; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011379:Prognosis; D012372:ROC Curve; D019275:Radiopharmaceuticals; D012008:Recurrence; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013625:Takayasu Arteritis / Q000097:blood / Q000000981:diagnostic imaging* / Q000188:drug therapy; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D015415:Biomarkers; D007166:Immunosuppressive Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002097:C-Reactive Protein