title: Preoperative liver volumetry: how does the slice thickness influence the multidetector computed tomography- and magnetic resonance-liver volume measurements?
abstract: OBJECTIVE
  The purpose was to investigate the influence of slice thickness on multidetector computed tomography (MDCT)- and magnetic resonance (MR)-based liver volumetry.
  
  
  METHODS
  Twenty patients who underwent liver surgery were imaged with either a 64-slice MDCT (n = 10) or a 1.5-T MR scanner (n = 10). Multidetector computed tomography and MR images were reconstructed using different slice thicknesses (2, 4, 6, and 8 mm). Total liver volumes (TLVs) were measured by 2 independent readers based on different slice thicknesses using semiautomatic software. Results were compared with TLVs based on 2-mm slices that served as standard of reference. The time to perform each volumetry was recorded.
  
  
  RESULTS
  For MDCT volumetry, a statistical difference was seen only between TLVs based on 2-mm versus 8-mm slices (P = 0.012 and P = 0.002 for readers 1 and 2, respectively). For MR volumetry, no statistical difference was seen between TLVs of the standard of reference and TLVs based on 4-, 6-, and 8-mm slices. Regarding the time to perform volumetry, there was a significant gain of time for both readers when volumetry was performed on 6- and 8-mm MDCT slices and on 4-, 6-, and 8-mm MR slices (P < 0.0167) when compared with the standard of reference.
  
  
  CONCLUSIONS
  The results of MDCT- and MR-based liver volumetry are dependent on slice thickness. With respect to the precision of calculated volumes and the significant gain of time, 6-mm slices are preferable for computed tomographic imaging, and 8-mm slices are preferable for MR imaging.
authors.affiliation: Institute of Diagnostic Radiology, Department of Radiology, University Hospital Zurich, Zurich, Switzerland. caecilia.reiner@usz.ch
authors.forename: Caecilia S
authors.initials: CS
authors.lastname: Reiner
authors.forename: Christoph
authors.initials: C
authors.lastname: Karlo
authors.forename: Henrik
authors.initials: H
authors.lastname: Petrowsky
authors.forename: Borut
authors.initials: B
authors.lastname: Marincek
authors.forename: Dominik
authors.initials: D
authors.lastname: Weishaupt
authors.forename: Thomas
authors.initials: T
authors.lastname: Frauenfelder
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D019412:Anatomy, Cross-Sectional / Q000379:methods*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D007089:Image Enhancement / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008099:Liver / Q000000981:diagnostic imaging* / Q000601:surgery; D008107:Liver Diseases / Q000000981:diagnostic imaging* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D009929:Organ Size; D011300:Preoperative Care / Q000379:methods; D011857:Radiographic Image Interpretation, Computer-Assisted / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014057:Tomography, X-Ray Computed / Q000379:methods*