title: Diffuse increased splenic F-18 fluorodeoxyglucose uptake may be an indirect sign of acute pyogenic cause rather than tuberculous in patients with infectious spondylitis.
abstract: OBJECTIVE
  The aim of this study was to investigate whether diffuse increased splenic fluorodeoxyglucose (FDG) uptake may be an indirect sign of an acute pyogenic cause of infectious spondylitis (IS).
  
  
  METHODS
  A retrospective review identified consecutive records of patients with IS who underwent F-18 FDG positron emission tomography-computed tomography scans between January 2007 and July 2008 and recruited 23 patients (57.8 ± 15.6 years, range: 20-81 years, eight men, 15 women) and their hematological laboratory data. The regions of interest were used to measure the maximum standardized uptake value (SUVmax) for the bone marrow (BM), liver, and spleen in each patient. We calculated the spleen/liver ratio (S/L ratio) by dividing the spleen SUVmax by liver SUVmax and the spleen/BM ratio (S/B ratio) by dividing spleen SUVmax by BM SUVmax as a parameter to assess the splenic FDG uptake.
  
  
  RESULTS
  The acute pyogenic cause of the IS group showed statistically significantly higher values of spleen SUVmax (median, 1.71 vs. 1.16, P=0.0108), S/L ratio (median, 1.08 vs. 0.88, P=0.0454), and S/B ratio (median, 1.30 vs. 0.94, P=0.0055) than the chronic tuberculous cause of the IS. The optimal cut-off values for the quantitative indices were spleen SUVmax>1.49, S/B ratio>0.957, and S/L ratio>0.889.
  
  
  CONCLUSIONS
  On the basis of the results presented, this study demonstrated that some quantitative indices from F-18 FDG positron emission tomography/computed tomography images could be indirect signs of an acute pyogenic cause of the IS. Among the various quantitative indices, spleen SUVmax, S/B ratio, and S/L ratio were potent indicators for an acute pyogenic cause of the IS.
authors.affiliation: Department of Nuclear Medicine, School of Medicine, Pusan National University, Busan, Republic of Korea.
authors.forename: Keunyoung
authors.initials: K
authors.lastname: Kim
authors.forename: Seong-Jang
authors.initials: SJ
authors.lastname: Kim
authors.forename: In Joo
authors.initials: IJ
authors.lastname: Kim
authors.forename: Bum Soo
authors.initials: BS
authors.lastname: Kim
authors.forename: Kyoungjune
authors.initials: K
authors.lastname: Pak
authors.forename: Heeyoung
authors.initials: H
authors.lastname: Kim
mesh_terms: D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow / Q000000981:diagnostic imaging; D002908:Chronic Disease; D003937:Diagnosis, Differential; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D006801:Humans; D008099:Liver / Q000000981:diagnostic imaging; D008159:Lumbar Vertebrae / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D013154:Spleen / Q000737:chemistry / Q000000981:diagnostic imaging; D013166:Spondylitis / Q000000981:diagnostic imaging* / Q000209:etiology; D013492:Suppuration / Q000150:complications; D014057:Tomography, X-Ray Computed; D014376:Tuberculosis / Q000150:complications / Q000000981:diagnostic imaging*; D055815:Young Adult
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18