Design and evaluation of a novel digital pathology ...digitalpathology2014.org/download/documenti/21014_14930.pdfDesign and evaluation of a novel digital pathology workstation for

www.virtualpathology.leeds.ac.uk

Design and evaluation of a novel digital pathology workstation for

clinical use

Darren Treanor BSc (Computing) MB BCh PhD FRCPath

Leeds Teaching Hospitals Trust & University of Leeds

12th European Congress on Digital Pathology, Paris, June 2014

[email protected]

www.virtualpathology.leeds.ac.uk @LeedsPathology

mailto:[email protected]

http://www.virtualpathology.leeds.ac.uk/


Context

• Leeds Teaching Hospitals NHS Trust

– 35 consultant pathologists

– 30 trainee pathologists

– ~ 250,000 H&E slides/ year in

“histopathology

• Scanning since 2003– 4 Aperio scanners

– >180,000 slides

– 160TB of image data

This is independent research carried out by us at the

University of Leeds/ Leeds Teaching Hospitals NHS

Trust funded by the UK National Institute for Health

Research (NIHR)

Conflict of interest statement: None to declare


All atwww.virtualpathology.leeds.ac.uk

Powerwall: 48 megapixels, size 3.5m x

1.5m, 2 on site at Hospital, 2 in University

Website: 10,000 + virtual slides, slide

library, e-learning, QA materials, papers,

videos and more


Background: There’s something wrong with digital pathology...

Poor acceptability

• Majority of pathologists feel virtual

slides are not suitable for clinical

diagnosis

Poor efficiency

• 60% less efficient than the

microscope

The virtual slide and conventional microscope – a direct comparison of their diagnostic efficiency.

Annual Meeting of the Pathological Society of Great Britain and Ireland. 2007, Glasgow.


Why are virtual slide viewers less efficient than the microscope?

• Display resolution

• Software performance (moving pixels)

• Software design

– GUI design adopted from photo editing software

• Lack of training and experience

• Other factors

– Lower image quality than microscope, at both image

capture and display stages


Why are virtual slides less efficient? The effect of display resolution

17” xga monitor shows 14% of the viewable area of the microscope field at 40x


Project overview

Study work

practices and

workflow

Develop a

digital

microscope

Evaluate the

system with

pathologists

To make a digital microscope as fast as, or faster

than, a conventional microscope


What we did

• Studied work in pathology

1. Quantitative

• Workload metrics

• Quantification of range of task types

performed with the microscope

2. Qualitative

• Observations, interviews

• Videos of work in the office, using the

microscope

3. Experimental

• Evaluation of workstation efficiency, utility

• Evaluation of specific UI questions

Randell R, Ruddle RA, Thomas R, Treanor D. “Diagnosis at the microscope: a workplace study of

histopathology.” Cognition, Technology & Work 2011 Aug.


Working in the office: time breakdown

54%

23%

10%

4%

3%

2% 2%1%

1%

Viewing slide

Dictation

Other

Computer

Notes

Annotating

Book

Paperwork

Filling forms

Randell R, Ruddle RA, Quirke P, Thomas RG, Treanor D. “Working at the microscope: analysis of the

activities involved in diagnostic pathology”. Histopathology 2011


Tracking at the microscope –a simple skin specimen

• Pathologists make hundreds of movements when viewing a slide

• Mean fixation time 1.3 – 2.0 seconds

• Follow complex paths

• The microscope is transparent to them – they focus on the image,

the pathology


Project overview

Study work

practices and

workflow

Develop a

digital

microscope

Evaluate the

system with

pathologists

To make a digital microscope as fast as, or faster than, a conventional microscope


Design, discussion, prototyping, more discussion


Leeds virtual microscope v2: Final design

• Fast pixel moving engine

• Medical grade monitors

– Barco Coronis 6MP plus Nio 3MP

– Total 9 megapixels – equivalent

visual FOV and resolution

as a microscope

• Novel “case view”

– Viewing multiple slides (26% of our

slide workload at Leeds)

– Increased reference to metadata

(“doing 2 things at once”)

– Generating complex reports

Microscope

Workstation


Workstation version 2 design: Screenshot


Slides with metadata displayed in 2D grid


Leeds virtual microscope v2.0video


Project overview

Study work

practices and

workflow

Develop a

digital

microscope

Evaluate the

system with

pathologists

To make a digital microscope as fast as, or faster than, a conventional microscope


Results: Similar time to complete the task on LVM

Device Mean

(%)

Median

(%)

Exposure

Leeds virtual

microscope

100.8 96.5 30 minutes

Microscope 99.3 112 10 years

Normalised time to complete task

Error bars show 95% confidence interval (CI)


Higher percentage of time spent viewing slides on LVM

Mean % time spent viewing slides

Error bars show 95% confidence interval (CI)

p < .05


Tracking shows pathologist returning to slides

• Suggests that confirming diagnosis, rather than relying on memory - or less

confident of decision?


And… more acceptable to pathologists!


Summary

• 5 year effort

• User centred design

• Multidisciplinary team

• Created

– Powerwall

– Desktop LVM

• Equivalent time to the microscope

• More time spent looking at the slides

• Acceptable to users


AcknowledgementsVirtual Pathology at University of Leeds• Phil Quirke• David Turner, Martin Waterhouse, Mike Hale, Alex Wright, Fraser Lewis, Hannah Dee, Gordon Hutchins• Nick Roberts, Richard Quirke, Mike Shires, Doreen Crellin, Nick Roberts (technical work)

Image analysis & computer vision at University of Leeds• Alex Wright & Andrew Bennett &Yanong Zhu, Pathology and Tumour Biology Group, Leeds Institute of

Molecular Medicine, University of Leeds• Ladislav Gubic, Jim Swainston, James Bridges, BSc students, School of Computing, University of Leeds• Andy Bulpitt, Derek Magee, Yi Song, Yu Zhou, School of Computing, University of Leeds

Visualisation & human computer interaction at University of Leeds• Roy Ruddle, Rhys Thomas, John Hodrien School of Computing• Rebecca Randell, Leeds Institute of Molecular Medicine

Collaborators/ supporters• Claudia Mello-Thoms, University of Pittsburgh• David Brettle, Leeds Teaching Hospitals Trust• Barco

Funding• Pathological Society of Great Britain and Ireland• Department of Health• Yorkshire Cancer Research• National Institute for Health Research


http://www.virtualpathology.leeds.ac.uk/


Documents

Design and evaluation of a novel digital pathology ...digitalpathology2014.org/download/documenti/21014_14930.pdfDesign and evaluation of a novel digital pathology workstation for