title: Validation of digital pathology imaging for primary histopathological diagnosis.
abstract: OBJECTIVE
  Digital pathology (DP) offers advantages over glass slide microscopy (GS), but data demonstrating a statistically valid equivalent (i.e. non-inferior) performance of DP against GS are required to permit its use in diagnosis. The aim of this study is to provide evidence of non-inferiority.
  
  
  RESULTS
  Seventeen pathologists re-reported 3017 cases by DP. Of these, 1009 were re-reported by the same pathologist, and 2008 by a different pathologist. Re-examination of 10 138 scanned slides (2.22 terabytes) produced 72 variances between GS and DP reports, including 21 clinically significant variances. Ground truth lay with GS in 12 cases and with DP in nine cases. These results are within the 95% confidence interval for existing intraobserver and interobserver variability, proving that DP is non-inferior to GS. In three cases, the digital platform was deemed to be responsible for the variance, including a gastric biopsy, where Helicobacter pylori only became visible on slides scanned at the ×60 setting, and a bronchial biopsy and penile biopsy, where dysplasia was reported on DP but was not present on GS.
  
  
  CONCLUSIONS
  This is one of the largest studies proving that DP is equivalent to GS for the diagnosis of histopathology specimens. Error rates are similar in both platforms, although some problems e.g. detection of bacteria, are predictable.
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.|Centre of Excellence for Digital Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: David R J
authors.initials: DR
authors.lastname: Snead
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.|Centre of Excellence for Digital Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Yee-Wah
authors.initials: YW
authors.lastname: Tsang
authors.affiliation: Centre of Excellence for Digital Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Aisha
authors.initials: A
authors.lastname: Meskiri
authors.affiliation: Warwick Medical School, University of Warwick, Coventry, UK.
authors.forename: Peter K
authors.initials: PK
authors.lastname: Kimani
authors.affiliation: Warwick Medical School, University of Warwick, Coventry, UK.
authors.forename: Richard
authors.initials: R
authors.lastname: Crossman
authors.affiliation: Centre of Excellence for Digital Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.|Department of Computer Science, University of Warwick, Coventry, UK.
authors.forename: Nasir M
authors.initials: NM
authors.lastname: Rajpoot
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Elaine
authors.initials: E
authors.lastname: Blessing
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Klaus
authors.initials: K
authors.lastname: Chen
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Kishore
authors.initials: K
authors.lastname: Gopalakrishnan
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Matthews
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.|Histopathology Department, City Hospital, Birmingham, UK.
authors.forename: Navid
authors.initials: N
authors.lastname: Momtahan
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Sarah
authors.initials: S
authors.lastname: Read-Jones
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Shatrughan
authors.initials: S
authors.lastname: Sah
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Emma
authors.initials: E
authors.lastname: Simmons
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Bidisa
authors.initials: B
authors.lastname: Sinha
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Sari
authors.initials: S
authors.lastname: Suortamo
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Yen
authors.initials: Y
authors.lastname: Yeo
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Hesham
authors.initials: H
authors.lastname: El Daly
authors.affiliation: Department of Cellular Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.|Centre of Excellence for Digital Pathology, University Hospitals of Coventry and Warwickshire NHS Trust, Coventry, UK.
authors.forename: Ian A
authors.initials: IA
authors.lastname: Cree
mesh_terms: D001706:Biopsy; D016001:Confidence Intervals; D003952:Diagnostic Imaging / Q000379:methods*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008853:Microscopy; D015588:Observer Variation; D010338:Pathology, Clinical / Q000379:methods*; D015203:Reproducibility of Results; D012189:Retrospective Studies
keywords: diagnosis; digital pathology; histopathology; validation; whole slide imaging