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Authors. Russell Silowash, BS Evaluation Team – Research Analyst Leslie Anthony, MA UPMC IMITS Telepathology Project – Project Manager Robb Wilson, MA Evaluation Team – Project Manager Dana Grzybicki, MD, PhD Evaluation Team – Principal Investigator. Background.
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Authors Russell Silowash, BS Evaluation Team – Research Analyst Leslie Anthony, MA UPMC IMITS Telepathology Project – Project Manager Robb Wilson, MA Evaluation Team – Project Manager Dana Grzybicki, MD, PhD Evaluation Team – Principal Investigator University of Pittsburgh Department of Biomedical Informatics
Background • Through appropriations in the defense-spending bills for 2002 and 2004, the University of Pittsburgh Medical Center (UPMC) and the United State Air Force Medical Service (AFMS) created a partnership called the Integrated Medical Information Technology System (IMITS) Program • Telepathology is a branch of the IMITS program that implements and validates digital pathology practices University of Pittsburgh Department of Biomedical Informatics
Introduction • Whole Slide Imaging (WSI) systems are increasingly popular within pathology practices • It is essential to acquire images that are diagnostically equivalent to glass slides • There are no validated assessments for evaluating WSI cases • The UPMC Digital Pathology Imaging Group is working on the validation of a unique evaluation tool University of Pittsburgh Department of Biomedical Informatics
Participants • 5 pathologists • 2 pathology fellows • 3 staff pathologists with training in GU pathology University of Pittsburgh Department of Biomedical Informatics
Apparatus • BX45 used to view glass slides • Aperio T2 robotic scanner • Aperio ImageScope browser used to view digital images of slides Prostate tissue viewed on Aperio ImageScope browser University of Pittsburgh Department of Biomedical Informatics
Case Selection • 30 difficult prostate biopsy foci University of Pittsburgh Department of Biomedical Informatics
Hypotheses • Internal Validity • There will be a positive correlation between the number of slides/images in a case and the time needed to complete the case • External Validity • Whole slide image quality will be positively correlated with glass slide quality University of Pittsburgh Department of Biomedical Informatics
Hypotheses (continued) • Construct Validity • There will be a negative correlation between the diagnostic confidence of a participant and the case complexity rating • Content Validity • The assessment is asking the proper questions for the study at hand University of Pittsburgh Department of Biomedical Informatics
Time Results Most cases took less than 15 minutes to complete for both WSI and glass phases University of Pittsburgh Department of Biomedical Informatics
Internal Validity Results • Positive correlation exists between WSI time per case and glass time per case • Statistically significant for only one participant (r2=0.327, p<0.01) University of Pittsburgh Department of Biomedical Informatics
External Validity Results • A positive correlation exists between WSI quality and glass slide quality University of Pittsburgh Department of Biomedical Informatics
External Validity Results (continued) • There were statistically significant positive correlations for 3 of the 5 subjects University of Pittsburgh Department of Biomedical Informatics
Construct Validity Results • Negative correlation exists in WSI phase of study between confidence in diagnosis and case complexity University of Pittsburgh Department of Biomedical Informatics
Construct Validity Results (continued) • Negative correlation exists in the Glass phase between case complexity and diagnostic confidence University of Pittsburgh Department of Biomedical Informatics
Construct Validity Results (continued) • 3 of 5 pathologists had statistically significant positive correlations in the WSI Phase • 4 of 5 pathologists had statistically significant positive correlations in the Glass Phase University of Pittsburgh Department of Biomedical Informatics
Content Validity Results • Content validity has been obtained by gaining feedback from pathologists that are part of the Digital Pathology Imaging Group (DPIG) University of Pittsburgh Department of Biomedical Informatics
Summary • We were able to establish external and construct validity, however internal validity is rather low. • Low internal validity could be due to time categories being too broad • Slide quality correlates positively with image quality, which suggests good/bad slides causes good/bad images • WSI may be used for more clinical applications University of Pittsburgh Department of Biomedical Informatics
Limitations • Only used 5 pathologist participants from UPMC who have had experience with WSI • Only prostate tissue examined University of Pittsburgh Department of Biomedical Informatics
Next Steps • Change the categories for the time variable • Implement an automatic timing solution University of Pittsburgh Department of Biomedical Informatics
Next Steps (continued) • Recruit more pathologists to participate in our validation studies • Other educational/medical institutions • Air Force • Expand across multiple tissue types University of Pittsburgh Department of Biomedical Informatics
Acknowledgements • We would like to acknowledge all of the members of the Digital Pathology Special Interest Group for their input and contributions towards this project, especially the Principal Investigator, Drazen Jukic,MD University of Pittsburgh Department of Biomedical Informatics
Funding • This work was supported by funding from the U.S. Air Force administered by the U.S. Army Medical Research Acquisition Activity, Fort Detrick, Maryland (Award No. W81XWH-04-2-0030 and Contract No. DAMD 17-0302-0017). The content of the information does not imply U.S. Air Force or Government endorsement of factual accuracy or opinion University of Pittsburgh Department of Biomedical Informatics