title: CT differentiation of pyogenic liver abscesses caused by Klebsiella pneumoniae vs non-Klebsiella pneumoniae.
abstract: OBJECTIVE
  Klebsiella pneumoniae is one of the organisms most commonly isolated from pyogenic liver abscesses in Asian populations. We compared CT findings in liver abscesses caused by K. pneumoniae with those caused by other bacterial pathogens.
  
  
  METHODS
  Of 214 patients with liver abscesses examined over a 5 year period, 129 patients with positive blood or aspirate cultures were enrolled. The patients were divided into two groups: the K. pneumoniae monomicrobial liver abscess (KLA) group (n = 59) and the non-K. pneumoniae monomicrobial or polymicrobial liver abscess (non-KLA) group (n = 70). Two radiologists blinded to the culture results evaluated the CT images, recording the number, size, location and configuration of abscesses, the thickness of the abscess wall, the pattern of rim enhancement, septal enhancement, the double target sign, internal necrotic debris, internal gas bubbles and underlying biliary disease. The presence of diabetes and metastatic infection was also compared between groups. Statistical analyses were performed using univariate (Student's t-test and χ(2) test) and multivariate analyses.
  
  
  RESULTS
  Multivariate analysis showed that a thin wall, necrotic debris, metastatic infection and the absence of underlying biliary disease were the most significant predictors of KLA. When three of the four criteria were used in combination, a specificity of 98.6% was achieved for the diagnosis of KLA.
  
  
  CONCLUSIONS
  A thin-walled abscess, internal necrotic debris, the presence of metastatic infection and the absence of underlying biliary disease may be useful CT findings in the early diagnosis of K. pneumoniae liver abscesses.
authors.affiliation: Department of Radiology, Pusan National University Hospital, Pusan National University School of Medicine and Medical Research Institute, Pusan National University, #1-10 Ami-Dong, Busan, Republic of Korea.
authors.forename: N K
authors.initials: NK
authors.lastname: Lee
authors.forename: S
authors.initials: S
authors.lastname: Kim
authors.forename: J W
authors.initials: JW
authors.lastname: Lee
authors.forename: Y J
authors.initials: YJ
authors.lastname: Jeong
authors.forename: S H
authors.initials: SH
authors.lastname: Lee
authors.forename: J
authors.initials: J
authors.lastname: Heo
authors.forename: D H
authors.initials: DH
authors.lastname: Kang
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D042241:Early Diagnosis; D005260:Female; D006801:Humans; D007710:Klebsiella Infections / Q000000981:diagnostic imaging* / Q000382:microbiology; D007711:Klebsiella pneumoniae / Q000302:isolation & purification*; D046290:Liver Abscess, Pyogenic / Q000000981:diagnostic imaging* / Q000382:microbiology*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D012189:Retrospective Studies; D013045:Species Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods