New Articles on Efficacy of Whole Slide Images/Virtual Microscopy

Couple of recent new articles on use of whole slide images/virtual microscopy for use in clinical, education and research. Increasingly, it is becoming clearer and clearer, that pathologists of today and tomorrow will have to train their analog eyes as well as their digital ones to get the full picture of disease without impairments of travel, time, place and most important, quality.

Observer agreement comparing the use of virtual slides with glass slides in the pathology review component of the POSH breast cancer cohort study

Abstract

Aims (1) To compare the use of scanned virtual slide images (virtual microscopy) with glass slides (conventional microscopy) in the assessment of morphological characteristics of breast cancers within the setting of the Prospective study of Outcomes in Sporadic versus Hereditary breast cancer (POSH), involving a cohort of women under 40 years of age, presenting with breast cancer. (2) To assess the acceptability to histopathologists of the use of virtual slide images.

Methods 13 histopathologists from the UK and Australia participated in the POSH pathology review. The observers were asked to assess multiple morphological features such as tumour grade and type. Comparisons were made for a single observer using both virtual images and glass slides. Intra- and inter-observer variability was calculated using the ? statistic and a comparison was made between the use of each image modality.

Results Diagnostic performance with virtual slides was comparable to conventional microscopic assessment, with the measurement of agreement best for vascular invasion, necrosis and the presence of a central scar (?=0.37–0.78), and poor for more subjective parameters such as pleomorphism, stroma, the nature of the tumour border and the degree of lymphocytic infiltrate (?=0.1).

Conclusion Virtual slides represent an acceptable methodology for central review of breast cancer histopathology and can circumvent the need for either travel to view material, or the potential problems of sending it by post.

J Clin Pathol 2012;65:403-408 doi:10.1136/jclinpath-2011-200369

Correspondence to: Dr Emily Clare Shaw, Department of Cellular Pathology, Mail point 2, Southampton General Hospital, Tremona Road, Southampton SO16 6YD, UK; ecshaw@doctors.org.uk

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Whole slide imaging (WSI) has been used in conjunction with virtual microscopy (VM) for training or proficiency testing purposes, multicentre research, remote frozen section diagnosis and to seek specialist second opinion in a number of organ systems. The feasibility of using WSI/VM for routine surgical pathology reporting has also been explored. In this review, we discuss the utility and limitations of WSI/VM technology in the histological assessment of specimens from the prostate. Features of WSI/VM that are particularly well suited to assessment of prostate pathology include the ability to examine images at different magnifications as well as to view histology and immunohistochemistry side-by-side on the screen. Use of WSI/VM would also solve the difficulty in obtaining multiple identical copies of small lesions in prostate biopsies for teaching and proficiency testing. It would also permit annotation of the virtual slides, and has been used in a study of i nter-observer variation of Gleason grading to facilitate precise identification of the foci on which grading decisions had been based. However, the large number of sections examined from each set of prostate biopsies would greatly increase time required for scanning as well as the size of the digital file, and would also be an issue if digital archiving of prostate biopsies is contemplated. Z-scanning of glass slides, a process that increases scanning time and file size would be required to permit focusing a virtual slide up and down to assess subtle nuclear features such as nucleolar prominence. The common use of large blocks to process prostatectomy specimens would also be an issue, as few currently available scanners can scan such blocks. A major component of proficiency testing of prostate biopsy assessment involves screening of the cores to detect small atypical foci. However, screening virtual slides of wavy fragmented prostate cores using a computer mouse aided by an overview image is very different from screening glass slides using a microscope stage. Hence, it may be more appropriate in this setting to mark the lesional area and focus only on the interpretation component of competency testing. Other issues limiting the use of digital pathology in prostate pathology include the cost of high quality slide scanners for WSI and high resolution monitors for VM as well as the requirement for fast Internet connection as even a subtle delay in presentation of images on the screen may be very disturbing for a pathologist used to the rapid viewing of glass slides under a microscope. However, these problems are likely to be overcome by technological advances in the future. © 2012 The Authors APMIS © 2012 APMIS.

APMIS 2012(Apr); 120(4): 298-304.
Utility of whole slide imaging and virtual microscopy in prostate pathology.
Camparo P, Egevad L, Algaba F, Berney DM, Boccon-Gibod L, Compérat E, Evans AJ, Grobholz R, Kristiansen G, Langner C, Lopez-Beltran A, Montironi R, Oliveira P, Vainer B, Varma M
Cabinet de Pathologie Amiens, France.
DOI: 10.1111/j.1600-0463.2011.02872.x
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Traditionally, education and training in pathology has been delivered using textbooks, glass slides and conventional microscopy. Over the last two decades, the number of web-based pathology resources has expanded dramatically with centralized pathological resources being delivered to many students simultaneously. Recently, whole slide imaging technology allows glass slides to be scanned and viewed on a computer screen via dedicated software. This technology is referred to as virtual microscopy and has created enormous opportunities in pathological training and education. Students are able to learn key histopathological skills, e.g. to identify areas of diagnostic relevance from an entire slide, via a web-based computer environment. Students no longer need to be in the same room as the slides. New human-computer interfaces are also being developed using more natural touch technology to enhance the manipulation of digitized slides. Several major initiatives are also underway introducing online competency and diagnostic decision analysis using virtual microscopy and have important future roles in accreditation and recertification. Finally, researchers are investigating how pathological decision-making is achieved using virtual microscopy and modern eye-tracking devices. Virtual microscopy and digital pathology will continue to improve how pathology training and education is delivered. © 2012 The Authors APMIS © 2012 APMIS.

APMIS 2012(Apr); 120(4): 305-15.
Virtual microscopy and digital pathology in training and education.
Hamilton PW, Wang Y, McCullough SJ
Centre for Cancer Research and Cell Biology, Queen's University Belfast, UK. p.hamilton@qub.ac.uk
DOI: 10.1111/j.1600-0463.2011.02869.x
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