title: Aortic ¹⁸F-FDG uptake in patients suffering from granulomatosis with polyangiitis.
abstract: OBJECTIVE
  The objective of the study was to systematically assess aortic inflammation in patients with granulomatosis with polyangiitis (GPA) using (18)F-2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) positron emission tomography (PET)/CT.
  
  
  METHODS
  Aortic inflammation was studied in PET/CT scans obtained from 21 patients with GPA; 14 patients with sarcoidosis were included as disease controls, 7 patients with stage I or II head and neck carcinoma ascertained during routine clinical practice were used as healthy controls (HC) and 5 patients with large vessel vasculitis (LVV) were used as positive controls. Aortic (18)F-FDG uptake was expressed as the blood-normalized maximum standardized uptake value (SUVmax), known as the target to background ratio (mean TBRmax).
  
  
  RESULTS
  The mean TBRmax (interquartile range) of the aorta in patients with GPA, sarcoidosis, HC and LVV were 1.75 (1.32-2.05), 1.62 (1.54-1.74), 1.29 (1.22-1.52) and 2.03 (1.67-2.45), respectively. The mean TBRmax was significantly higher in patients suffering from GPA or LVV compared to HC (p < 0.05 and p < 0.005, respectively) and tended to be higher in patients suffering from sarcoidosis, but this did not reach statistical significance (p = 0.098). The mean TBRmax of the most diseased segment was significantly higher compared to HC [1.57 (1.39-1.81)] in LVV patients [2.55 (2.22-2.82), p < 0.005], GPA patients [2.17 (1.89-2.83), p < 0.005] and patients suffering from sarcoidosis [2.04 (1.88-2.20), p < 0.05]. In GPA patients, the mean TBRmax of the aorta was significantly higher in patients with previous renal involvement [2.01 (1.69-2.53)] compared to patients without renal involvement in the past [1.60 (1.51-1.80), p < 0.05]. Interrater reproducibility with a second reader was high (all intraclass correlation coefficients >0.9).
  
  
  CONCLUSIONS
  Patients suffering from GPA show marked aortic FDG uptake.
authors.affiliation: Department of Nephrology and Clinical Immunology, Maastricht University Medical Center, Maastricht, The Netherlands.
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Kemna
authors.forename: Jan
authors.initials: J
authors.lastname: Bucerius
authors.forename: Marjolein
authors.initials: M
authors.lastname: Drent
authors.forename: Stefan
authors.initials: S
authors.lastname: Vöö
authors.forename: Martine
authors.initials: M
authors.lastname: Veenman
authors.forename: Pieter
authors.initials: P
authors.lastname: van Paassen
authors.forename: Jan Willem Cohen
authors.initials: JW
authors.lastname: Tervaert
authors.forename: Marinus J P G
authors.initials: MJ
authors.lastname: van Kroonenburgh
mesh_terms: D001011:Aorta / Q000000981:diagnostic imaging / Q000378:metabolism*; D001692:Biological Transport; D016022:Case-Control Studies; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism*; D014890:Granulomatosis with Polyangiitis / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000378:metabolism*; D006801:Humans; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D049268:Positron-Emission Tomography; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed
chemical_list: D019788:Fluorodeoxyglucose F18