title: Computed tomography liver volumetry using 3-dimensional image data in living donor liver transplantation: effects of the slice thickness on the volume calculation.
abstract: The purpose of this study was to evaluate the relationship between the slice thickness and the calculated volume in computed tomography (CT) liver volumetry through the comparison of the results from images [including 3-dimensional (3D) images] with various slice thicknesses. Twenty potential adult liver donors (12 men and 8 women) with a mean age of 39 years (range = 24-64 years) underwent CT with a 64-section multidetector row CT scanner after the intravenous injection of a contrast material. Four image sets with slice thicknesses of 0.625, 2.5, 5, and 10 mm were used. First, a program developed in our laboratory for automated liver extraction was applied to the CT images, and the liver boundaries were determined automatically. Then, an abdominal radiologist reviewed all images onto which automatically extracted boundaries had been superimposed and then edited the boundaries on each slice to enhance the accuracy. The liver volumes were determined via the counting of the voxels within the liver boundaries. The mean whole liver volumes estimated with CT were 1322.5 cm(3) from 0.625-mm images, 1313.3 cm(3) from 2.5-mm images, 1310.3 cm(3) from 5-mm images, and 1268.2 cm(3) from 10-mm images. The volumes calculated from 3D (0.625-mm) images were significantly larger than the volumes calculated from thicker images (P < 0.001). The partial liver volumes of right lobes, left lobes, and lateral segments were evaluated in a similar manner. The estimated maximum difference in the calculated volumes of lateral segments was -10.9 cm(3) (-4.63%) between 0.625- and 5-mm images. In conclusion, liver volumes calculated from 2.5-mm-thick or thicker images are significantly smaller than liver volumes calculated from 3D images. If a maximum error of 5% in the calculated graft volume will not have a significant clinical impact, 5-mm-thick images are acceptable for CT volumetry. If the impact is significant, 3D images could be essential.
authors.affiliation: Department of Radiology, University of Chicago, Chicago, IL 60637, USA. mhori@radiol.med.osaka-u.ac.jp
authors.forename: Masatoshi
authors.initials: M
authors.lastname: Hori
authors.forename: Kenji
authors.initials: K
authors.lastname: Suzuki
authors.forename: Mark L
authors.initials: ML
authors.lastname: Epstein
authors.forename: Richard L
authors.initials: RL
authors.lastname: Baron
mesh_terms: D000328:Adult; D003198:Computer Simulation; D003287:Contrast Media; D005260:Female; D006498:Hepatectomy; D006801:Humans; D021621:Imaging, Three-Dimensional; D008099:Liver / Q000000981:diagnostic imaging* / Q000601:surgery*; D016031:Liver Transplantation; D019520:Living Donors; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D009716:Numerical Analysis, Computer-Assisted; D009929:Organ Size; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed; D055815:Young Adult
chemical_list: D003287:Contrast Media