title: Computer-based liver volumetry in the liver perfusion simulator.
abstract: BACKGROUND
  An exact preoperative liver volume calculation is important prior to liver surgery and living-related liver transplantation. However, CT or MRI assessment of preoperative liver volume is associated with an estimation error of 1.2% to 36%, and little data is available on its accuracy on the segmental level. The aim of this study was to validate arterial and portal venous flow rates and gain information on liver volumetry, including liver segments, in the liver perfusion simulator and compare it to in vivo measurements in a porcine model.
  
  
  METHODS
  The arterial and portal venous flow rates and liver volumes of 10 pigs were measured in vivo and compared with the flow rates and volumes ex vivo. CT scans were performed and the volume of the liver and its lobes calculated by water displacement or computer-assistance based on the CT scans. The right lateral lobe was plasticized and reconstructed for the volume calculation.
  
  
  RESULTS
  In the liver perfusion simulator, arterial and portal venous flow rates comparable to the in vivo rates were achieved. The liver volume had a mean difference of 10.3% between in vivo and ex vivo measurements. In the liver perfusion simulator, the mean deviation in liver volume between the computer calculation and water displacement was 2.8%. On the segmental level, the Heidelberg algorithm provided an accuracy of 97.7%.
  
  
  CONCLUSIONS
  The liver perfusion simulator is an excellent device for studies in liver perfusion and volumetry. Furthermore, the simulator is applicable for teaching and performing interventions and surgeries in livers.
authors.affiliation: Department of General, Visceral and Transplant Surgery, University of Heidelberg, Germany.
authors.forename: Sascha Arian
authors.initials: SA
authors.lastname: Müller
authors.forename: Frank
authors.initials: F
authors.lastname: Pianka
authors.forename: Max
authors.initials: M
authors.lastname: Schöbinger
authors.forename: Arianeb
authors.initials: A
authors.lastname: Mehrabi
authors.forename: Hamid
authors.initials: H
authors.lastname: Fonouni
authors.forename: Boris
authors.initials: B
authors.lastname: Radeleff
authors.forename: Hans-Peter
authors.initials: HP
authors.lastname: Meinzer
authors.forename: Bruno M
authors.initials: BM
authors.lastname: Schmied
mesh_terms: D000465:Algorithms; D000818:Animals; D003198:Computer Simulation; D005260:Female; D006499:Hepatic Artery; D008099:Liver / Q000033:anatomy & histology / Q000098:blood supply* / Q000000981:diagnostic imaging* / Q000601:surgery; D016031:Liver Transplantation; D023421:Models, Animal; D009929:Organ Size; D010968:Plasticizers; D011169:Portal Vein; D011300:Preoperative Care / Q000379:methods / Q000592:standards; D011652:Pulmonary Circulation; D015203:Reproducibility of Results; D034421:Sus scrofa; D036542:Tomography, Spiral Computed / Q000379:methods / Q000592:standards*
chemical_list: D010968:Plasticizers