title: Lung perfusion CT: the differentiation of cavitary mass.
abstract: OBJECTIVE
  To assess the findings of perfusion maps and to evaluate the usefulness of perfusion computed tomography (CT) in the differentiation of cavitary mass.
  
  
  METHODS
  Fifty-three patients with cavitary lung masses were analyzed. Dynamic chest CT was performed after contrast injection. The volume map, washout map, peak map, and time-to-peak (TTP) map were reformatted using Interactive Data Language (IDL). The perfusion patterns were classified into three scoring groups, and these scorings were repeated after 2-week intervals. Diagnostic confidence levels were assigned by consensus. The kappa statistics was used to determine intraobserver agreement, and Fisher's exact test was used to analyze statistical differences in perfusion scores. Receiver operating characteristic (ROC) analysis was performed to evaluate the usefulness of the perfusion maps.
  
  
  RESULTS
  Perfusion maps were reformatted pixel-by-pixel from the time-to-density curve analyses. Pyogenic cavities showed weak washout and slow TTP (69.6%). Conversely, malignant cavities showed strong washout (73.3%). Tuberculous cavities showed low perfusions in the volume and peak maps (66.7%). Intraobserver agreement was excellent. The performance of the combination of CT and perfusion maps was better than that of CT alone.
  
  
  CONCLUSIONS
  Lung perfusion CT could be a promising and feasible method for differentiation of cavitary mass.
authors.affiliation: Department of Radiology, Yonsei University Wonju College of Medicine, 162 Ilsan-dong, Wonju, Korea.
authors.forename: Young Han
authors.initials: YH
authors.lastname: Lee
authors.forename: Woocheol
authors.initials: W
authors.lastname: Kwon
authors.forename: Myung Soon
authors.initials: MS
authors.lastname: Kim
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Kim
authors.forename: Myeong Sub
authors.initials: MS
authors.lastname: Lee
authors.forename: Suk Joong
authors.initials: SJ
authors.lastname: Yong
authors.forename: Soon-Hee
authors.initials: SH
authors.lastname: Jung
authors.forename: Sei-Jin
authors.initials: SJ
authors.lastname: Chang
authors.forename: Ki Joon
authors.initials: KJ
authors.lastname: Sung
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008168:Lung / Q000000981:diagnostic imaging*; D008171:Lung Diseases / Q000000981:diagnostic imaging; D008297:Male; D008875:Middle Aged; D055420:Perfusion Imaging / Q000379:methods*; D003074:Solitary Pulmonary Nodule / Q000000981:diagnostic imaging*; D014057:Tomography, X-Ray Computed / Q000379:methods*