title: Quantitative radiology: automated CT liver volumetry compared with interactive volumetry and manual volumetry.
abstract: OBJECTIVE
  The purpose of this study was to evaluate automated CT volumetry in the assessment of living-donor livers for transplant and to compare this technique with software-aided interactive volumetry and manual volumetry.
  
  
  METHODS
  Hepatic CT scans of 18 consecutively registered prospective liver donors were obtained under a liver transplant protocol. Automated liver volumetry was developed on the basis of 3D active-contour segmentation. To establish reference standard liver volumes, a radiologist manually traced the contour of the liver on each CT slice. We compared the results obtained with automated and interactive volumetry with those obtained with the reference standard for this study, manual volumetry.
  
  
  RESULTS
  The average interactive liver volume was 1553 ± 343 cm(3), and the average automated liver volume was 1520 ± 378 cm(3). The average manual volume was 1486 ± 343 cm(3). Both interactive and automated volumetric results had excellent agreement with manual volumetric results (intraclass correlation coefficients, 0.96 and 0.94). The average user time for automated volumetry was 0.57 ± 0.06 min/case, whereas those for interactive and manual volumetry were 27.3 ± 4.6 and 39.4 ± 5.5 min/case, the difference being statistically significant (p < 0.05).
  
  
  CONCLUSIONS
  Both interactive and automated volumetry are accurate for measuring liver volume with CT, but automated volumetry is substantially more efficient.
authors.affiliation: Department of Radiology, The University of Chicago, 5841 S Maryland Ave, MC 2026, Chicago, IL 60637, USA. suzuki@uchicago.edu
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Mark L
authors.initials: ML
authors.lastname: Epstein
authors.forename: Ryan
authors.initials: R
authors.lastname: Kohlbrenner
authors.forename: Shailesh
authors.initials: S
authors.lastname: Garg
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hori
authors.forename: Aytekin
authors.initials: A
authors.lastname: Oto
authors.forename: Richard L
authors.initials: RL
authors.lastname: Baron
mesh_terms: D000328:Adult; D001331:Automation; D003287:Contrast Media / Q000008:administration & dosage; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D007472:Iohexol / Q000008:administration & dosage; D008099:Liver / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D016031:Liver Transplantation; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012984:Software; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D003287:Contrast Media; D007472:Iohexol