title: The evaluation of colon biopsies using virtual microscopy is reliable.
abstract: OBJECTIVE
  Virtual microscopy offers major advantages for pathology practice, separating slide evaluation from slide production. The aim of this study was to investigate the reliability of using whole slide images as compared with routine glass slides for diagnostic purposes.
  
  
  RESULTS
  Colon biopsies (n = 295) were assessed using both glass slides and whole slide images by four pathologists and two residents. Two pathologists scored the digital images of biopsies in a primary diagnostic setting. For each case, the consensus diagnosis was defined as the majority diagnosis on the study's glass slides. All diagnoses were grouped into seven main diagnostic categories, and further divided into subgroups. The overall concordance rates were 89.6% for whole slide images and 91.6% for light microscopy. The concordance rates of the subgroups 'adenoma' and 'adenocarcinoma' between whole slide images and conventional microscopy showed only small variability. The intraobserver (whole slide images versus glass slide) agreement, including subgroups, was substantial, with a mean κ-value of 0.78, and was higher than the interobserver agreement for glass slides (interobserver κ-value of 0.69).
  
  
  CONCLUSIONS
  This study shows good diagnostic accuracy and reproducibility for virtual microscopy, indicating that this technology can reliably be used for pathological evaluation of colon biopsies in a primary clinical setting.
authors.affiliation: Department of Pathology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands. c.vanderpost@pathol.umcn.nl
authors.forename: Rachel S
authors.initials: RS
authors.lastname: van der Post
authors.forename: Jeroen A W M
authors.initials: JA
authors.lastname: van der Laak
authors.forename: Bart
authors.initials: B
authors.lastname: Sturm
authors.forename: Ruud
authors.initials: R
authors.lastname: Clarijs
authors.forename: H Ewout
authors.initials: HE
authors.lastname: Schaafsma
authors.forename: J Han J M
authors.initials: JH
authors.lastname: van Krieken
authors.forename: Marius
authors.initials: M
authors.lastname: Nap
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000473:pathology; D000236:Adenoma / Q000175:diagnosis* / Q000473:pathology; D001706:Biopsy / Q000379:methods; D003106:Colon / Q000473:pathology*; D003110:Colonic Neoplasms / Q000175:diagnosis* / Q000473:pathology; D006801:Humans; D008853:Microscopy; D010338:Pathology, Clinical; D015203:Reproducibility of Results