Influence of displays parameters on digital pathology systems

Cédric Marchessoux

Resolution

� Chest x-ray:

▫ #2000x2000 pixels

� Pathology image:

▫ #100000x100000 pixels

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Source: University of Leeds – Darren Treanor

Comparison between a radiographicimage and a digital slide

Resolution for Digital Pathology

� We have up to 12 Million Pixels for radiology with last Barco technology display:

� And for Digital Pathology less pixels? whereas in Digital pathology images are 20 times bigger?

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Interview of a Pathologist in UK in 2015

“Pathologists need even better displays than radiologists and not the contrary, higher resolution because of the resolution of a slide and a good color representation”

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Comparison study of the impact of the display resolution for digital pathology

� C. Marchessoux, A. Naves-Dufour, K. Espig, S. Monaco, A. Palekar and L. Pantanowitz

� Barco and UPMC Pittsburgh

� Work done not in the context of the Aidpath project

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Protocol

� 3 Displays:

▫ Same maximum luminance: 400cd/m²

▫ Same brand: Barco

▫ 3 different resolutions: 2MP, 4MP, 12MP

� 3 pathologists from UPMC

� 1 session per display:

▫ 70 images in total

▫ 10 1st images used for training

▫ 60 last images for the statistical analysis

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Images

� 70 images with wide variety of histological and cytological diagnoses

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Viewing software and scanner

� Aperio Scanscope v1 scanner

� Barco internal GPU optimized viewer for digital pathology

� Any interaction such as a click, a zoom or a panning action is recorded in an output log file for running automatic analysis

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Viewer

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MiniMap

Main Window

Scoring WindowWith description

The task

� Each case has be visualized on each monitor by each observer

� Each observer had to score each case with a scale from 0 to 3+

▫ 0: negative

▫ +: positive with degree of severity

� There was no control of the environment

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Analysis

� Number of pans

� Number of zooms

� Efficiency with the definition of a new metric

� Simple statistics with boxplots

� 2D and 3D plots

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average

median

2D plots

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In the minimap

In the main window

3D plots

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In the minimap

In the main window

Video generation

� By reproducing exactly the navigation of the pathologists

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Results: number of pan actions

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For all images, per observer & per display

Results: number of zoom actions

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For all images, per observer & per display

Grid: 3x3: 3 observers x 3 monitors

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The row = observer numberThe column = monitor number from 2MP to 12MP

Mon12MP

Mon24MP

Mon312MP

Obs1

Obs2

Obs3

Results: zoom box plots

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Results: zoom box plots

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2MP 4MP 12MP

Trend with higher resolution to go to “1” as zoom value, More pixels at natural scale 1:1 with higher resolution displays

Results: 3D navigation graph

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2MP 4MP 12MP

Results: efficiency

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How to judgeefficiency?

Results: efficiency

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How to judgeefficiency?

2MP

obs1

obs2

obs3

4MP 12MP

Results: efficiency

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ComplexNavigation

But for the 8 otherhow to rank them?

Metric Efficiency: definition

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Metric Efficiency: results

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Metric Efficiency: results

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Conclusion

� Less interaction and more time spent on the image with higher resolution displays for digital pathology

� Resolution (number of pixels) seems to play a major role in digital pathology

� Study should be redone with more observers

� (all analysises and plot generations done in python (oriented object)

� python is free, cross platform and so what: it is Magick!

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