title: Stereological quantification of microvessels using semiautomated evaluation of X-ray microtomography of hepatic vascular corrosion casts.
abstract: OBJECTIVE
  Quantitative description of hepatic microvascular bed could contribute to understanding perfusion CT imaging. Micro-CT is a useful method for the visualization and quantification of capillary-passable vascular corrosion casts. Our aim was to develop and validate open-source software for the statistical description of the vascular networks in micro-CT scans.
  
  
  METHODS
  Porcine hepatic microvessels were injected with Biodur E20 resin, and the resulting corrosion casts were scanned with 1.9-4.7 [Formula: see text] resolution. The microvascular network was quantified using newly developed QuantAn software both in randomly selected volume probes (n = 10) and in arbitrarily outlined hepatic lobules (n = 4). The volumes, surfaces, lengths, and numbers of microvessel segments were estimated and validated in the same data sets with manual stereological counting. Calculations of tortuosity, radius histograms, length histograms, exports of the skeletonized vascular network into open formats, and an assessment of the degree of their anisotropy were performed.
  
  
  RESULTS
  Within hepatic lobules, the microvessels had a volume fraction of 0.13 [Formula: see text] 0.05, surface density of 21.0 [Formula: see text] 2.0 [Formula: see text], length density of 169.0 [Formula: see text] 40.2 [Formula: see text], and numerical density of 588.5 [Formula: see text] 283.1 [Formula: see text]. Sensitivity analysis of the automatic analysis to binary opening, closing, threshold offset, and aggregation radius of branching nodes was performed.
  
  
  CONCLUSIONS
  The software QuantAn and its source code are openly available to researchers working in the field of stochastic geometry of microvessels in micro-CT scans or other three-dimensional imaging methods. The implemented methods comply with reproducible stereological techniques, and they were highly consistent with manual counting. Preliminary morphometrics of the classical hepatic lobules in pig were provided.
authors.affiliation: European Centre of Excellence NTIS, Faculty of Applied Sciences, University of West Bohemia, Univerzitní 22, 306 14, Pilsen, Czech Republic.|Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Miroslav
authors.initials: M
authors.lastname: Jiřík
authors.affiliation: European Centre of Excellence NTIS, Faculty of Applied Sciences, University of West Bohemia, Univerzitní 22, 306 14, Pilsen, Czech Republic. zbynek.tonar@lfp.cuni.cz.
authors.forename: Zbyněk
authors.identifier: http://orcid.org/0000-0002-7200-9894
authors.initials: Z
authors.lastname: Tonar
authors.affiliation: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarska 48, 301 66, Pilsen, Czech Republic.
authors.forename: Anna
authors.initials: A
authors.lastname: Králíčková
authors.affiliation: Department of Anatomy, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarska 48, 301 66, Pilsen, Czech Republic.|Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Lada
authors.initials: L
authors.lastname: Eberlová
authors.affiliation: Department of Imaging methods, Faculty of Medicine and University Hospital in Pilsen, Alej Svobody 80, 304 60, Pilsen, Czech Republic.|Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Hynek
authors.initials: H
authors.lastname: Mírka
authors.affiliation: European Centre of Excellence NTIS, Faculty of Applied Sciences, University of West Bohemia, Univerzitní 22, 306 14, Pilsen, Czech Republic.
authors.forename: Petra
authors.initials: P
authors.lastname: Kochová
authors.affiliation: New Technologies - Research Centre, University of West Bohemia, Univerzitní 8, 306 14, Pilsen, Czech Republic.
authors.forename: Tomáš
authors.initials: T
authors.lastname: Gregor
authors.affiliation: Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Petr
authors.initials: P
authors.lastname: Hošek
authors.affiliation: Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Miroslava
authors.initials: M
authors.lastname: Svobodová
authors.affiliation: European Centre of Excellence NTIS, Faculty of Applied Sciences, University of West Bohemia, Univerzitní 22, 306 14, Pilsen, Czech Republic.
authors.forename: Eduard
authors.initials: E
authors.lastname: Rohan
authors.affiliation: Department of Histology and Embryology, Faculty of Medicine in Pilsen, Charles University in Prague, Karlovarska 48, 301 66, Pilsen, Czech Republic.|Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.
authors.forename: Milena
authors.initials: M
authors.lastname: Králíčková
authors.affiliation: Biomedical Center, Faculty of Medicine in Pilsen, Charles University in Prague, Alej Svobody 76, 323 00, Pilsen, Czech Republic.|Department of Surgery, Faculty of Medicine in Pilsen, Charles University in Prague, Husova 3, 306 05, Pilsen, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Liška
mesh_terms: D000818:Animals; D003343:Corrosion; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging*; D055806:Microvessels / Q000000981:diagnostic imaging*; D012984:Software; D013552:Swine; D055114:X-Ray Microtomography / Q000379:methods*
keywords: Liver; Microvessels; Pig; Porcine; Python; Stereology; X-ray microtomography