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Going glass to digital: virtual microscopy as a simulation-based revolution in pathology and laboratory science
  1. Danielle Nelson1,
  2. Amitai Ziv2,3,
  3. Karim S Bandali1
  1. 1The Michener Institute for Applied Health Sciences, Toronto, Ontario, Canada
  2. 2The Israel Center for Medical Simulation, Sheba Medical Center, Tel-Hashomer, Israel
  3. 3Sackler School of Medicine, Tel-Aviv University, Tel-Aviv, Israel
  1. Correspondence to Dr Karim S Bandali, The Michener Institute for Applied Health Sciences, 222 St Patrick Street, Toronto, Ontario M5T 1V4, Canada; kbandali{at}


The recent technological advance of digital high resolution imaging has allowed the field of pathology and medical laboratory science to undergo a dramatic transformation with the incorporation of virtual microscopy as a simulation-based educational and diagnostic tool. This transformation has correlated with an overall increase in the use of simulation in medicine in an effort to address dwindling clinical resource availability and patient safety issues currently facing the modern healthcare system. Virtual microscopy represents one such simulation-based technology that has the potential to enhance student learning and readiness to practice while revolutionising the ability to clinically diagnose pathology collaboratively across the world. While understanding that a substantial amount of literature already exists on virtual microscopy, much more research is still required to elucidate the full capabilities of this technology. This review explores the use of virtual microscopy in medical education and disease diagnosis with a unique focus on key requirements needed to take this technology to the next level in its use in medical education and clinical practice.

  • Digital pathology
  • medical education
  • diagnosis
  • hematopathology
  • haematology
  • cytology

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Current changes in modern healthcare delivery, including decreased resource availability, increased awareness for patient safety, and a growing understanding of the importance of teamwork in the healthcare environment, have all contributed to an increased usage of simulation-based tools and techniques in medical education.1–4 Such tools have been available for many years in various aspects of medicine, including surgical skills training and anaesthesia,5 and vary in fidelity and sophistication depending on the competency to be taught.6 Low complexity simulators are the standard for introducing and teaching fundamental skill sets, such as phlebotomy arm models for venepuncture techniques and mannequins for resuscitation training.1 ,7 ,8 Higher complexity simulation tools, including screen-based anaesthesia simulators, are also widely used for knowledge and cognitive learning.9 High fidelity simulation platforms, such as simulated surgical suites, may be used to explore in depth learning curves and collaboration among various workers in a specific situation.10 ,11 Regardless of their complexity, these medical simulation tools all have a place within the learning process.6

The use of simulation in medical education addresses many problems a traditional system of education could not adequately support. Simulation allows for students to enhance their technical and decision making skills by practicing various procedures and techniques in a safe, risk-free environment,12 and has been shown in several studies to improve students' self-confidence, collaboration skills and communication abilities.13–16 Simulation allows for students to gain first-hand knowledge through hands-on repetition in an atmosphere which openly allows for errors to be made, corrected and learnt from in a meaningful context.1 Using simulation, various clinical conditions and situations, including rare and complex cases, can be readily investigated outside of the clinical setting.17 Consequently, the need to find appropriate patients, as well as the scarcity of clinical placements and unique scenarios, is no longer a severe limitation to the learning process.

Through recent advances in high-resolution imaging, pathology and laboratory medicine have embraced simulation in education through the incorporation of virtual microscopy as a screen-based simulation tool.6 ,18 Virtual microscopy, also known as digital slide technology (DST) or whole slide imaging, consists of digitising glass slide specimens to create dynamic images, which are viewed and manipulated using computer-based technology, closely mimicking traditional light microscopy.19 With many of its reported advantages over traditional microscopy, virtual microscopy has potential in both medical education and clinical pathology as a tool that could be optimised for enhanced student learning and readiness to practice, as well as for collaborative clinical diagnosis. The aim here is to discuss the use of virtual microscopy in pathology and laboratory medicine, specifically exploring key concepts required to elevate this technology to new levels of successful utilisation in healthcare education and clinical practice.

Taking microscopy to a whole new level

Virtual microscopy provides a number of advantages over traditional microscopy. Rare and complex cases that traditionally would have only been experienced by students and/or pathologists at a particular educational site now have the potential through the application of this technology of being incorporated into a standardised learning experience for all students and pathologists with progressively easier access and use.18 Correspondingly, clinical cases now have the potential benefit of a collaborative diagnosis by a team of pathologists from any region of the world.20–23 At the University Health Network's joint pathology department in Toronto, Canada, digitisation of frozen sections, ultra-rush biopsies and routine surgical pathology slides have allowed pathologists to remotely collaborate with other clinicians on difficult cases within clinically relevant timeframes. This has led to increased productivity of individual pathologists while maintaining a high degree of diagnostic accuracy.20

Virtual microscopy pilot studies have also indicated that there is significant potential for this technology to help improve medical treatment standards for patients in developing countries.22 ,23 Virtual microscopy could address challenges related to the lack of adequate medical staff and infrastructure which can impair appropriate medical diagnosis and treatment.22 Through the use of this technology, clinicians in these areas could be provided with diagnoses from pathology experts anywhere in the world. This information could then be used to better guide patient care and treatment. However, the reality remains that since current implementation and maintenance costs of this technology can be quite substantial,24 medical institutions in developing countries are not yet able to fully embrace this technology. Nevertheless, as technology costs, in general, become increasingly more financially manageable, virtual microscopy remains a hopeful opportunity for these patients to receive medical diagnoses and subsequent treatment more closely resembling the standards found in westernised society.22

Despite the potential advantages of this technology for increasing clinical workflow efficiencies as well as case specific collaborations, establishing and empowering communities of learners and clinicians with the ultimate potential benefit of enhanced patient care, full implementation of virtual microscopy is not without controversy. Lack of licensing and liability standards, combined with a need for thorough validation studies, has restricted similar diagnostic consultation via virtual microscopy when compared to traditional glass slides.25 Furthermore, diagnostic discrepancies have been noted in several cases, being attributed in part to image quality such as poor colour translation to virtual slides,26–28 focus imperfections from scanning,28 ,29 and image compression artefacts leading to loss of detail.29 However, the majority of the literature reports that there is no significant difference in diagnostic abilities with virtual slides in comparison to glass slides.20 ,26–34 With recent technological advancements towards multiplane focusing of slides, where most current virtual slides contain only one focal plane,35 as well as advancements in image formatting,36 there is a significant opportunity to enhance the image quality of virtual slides, thereby improving on its current use in pathology, as well as expanding its application to other medical disciplines.

While some controversy does exist, the global collaborative attractiveness of virtual microscopy, particularly in diagnostics, continues to demonstrate its value in multiple areas of medicine as exemplified by its growing adoption in continuous quality improvement and national proficiency testing initiatives. Much of this work has been focused on diagnostic cytology and haematology quality assessments for technologists and pathologists in these areas, with the main advantage being that this technology could allow for slides to be reviewed over the internet in a time-saving and cost-effective manner.37–39 Preliminary evidence also demonstrates that virtual microscopy may be an effective tool for the administration of competency exams for diagnostic capabilities of surgical pathology residents.40 Current approaches to these assessments have been described as often being biased, highly subjective, or in the case of multiple choice questions, tend to test knowledge as opposed to performance.40 Virtual microscopy could help address these issues and bring current practice better in line with competency mandates of licensing and regulatory bodies.40

From a more practical sense, virtual microscopy can assist in archiving glass slide collections for educational and clinical research purposes. Typically these collections are too large to adequately maintain using traditional methodologies.41 It also eliminates the need to prepare and ship slides for collaboration at multiple sites, which is not only time consuming and costly, but also holds an additional and constant risk of slide breakage before, during and after use. With the advent of several online databases of virtual slides, many digital slides can now also be viewed publicly over the internet.18 ,42 These images could also be integrated with other online clinical content, such as gross anatomy images, to further enhance the learning process.43 While much of this technology is used to help teach students basics in histology and histopathology,44–48 virtual microscopy has also expanded into other aspects of medical science, including dentistry and veterinary medicine,49–51 and has been explored for application in the area of transplantation pathology.52

As with many new technical-based tools, the implementation and maintenance of virtual microscopy can be costly.24 This applies not only to the hardware itself but also to the storage of digital slides, as these files can be quite large and significant space is required to store these images.53 However, while storage capabilities are of particular importance for educational purposes as educators strive to create databases of slides, advancements in image formatting and storage have made the cost of archiving virtual slides much more reasonable.36 Additionally, taking into account the cost of replacing traditional microscopes, as well as producing and maintaining glass slide sets, the cost of virtual microscopy in comparison to traditional microscopy may not be that different.18

As the use of virtual microscopy continues to gain momentum in clinical practice, the investment in education to support its ongoing development and innovative use through a new generation of clinicians is essential. Virtual microscopy is uniquely poised to transcend the world of simulation-based education and become an example of how new technology that is being developed can be applicable not only in the educational setting as a powerful simulation-based tool but also as a technology capable of having significant clinical application. With the continuous evolution of the healthcare system, decreased availability of clinical teaching resources and ongoing concerns about patient safety, virtual microscopy can be leveraged in a manner to not only be used as a simulation-based tool in a discipline specific manner but also to be incorporated into collaborative interprofessional learning. In particular, due to its digital interface, the integration of virtual microscopy into the electronic medical record could introduce a whole new level of complexity and potential which makes this technology an ideal candidate to explore in regard to collaborative patient-centred care. Therefore, further development and innovation of this technology in a multifaceted manner with the ultimate goal of better preparing students and potentially current and future clinicians will require the development of a curriculum that is equally as innovative in its support, application and vision.

A unique academic case study

At the Michener Institute for Applied Health Sciences (Michener) in Toronto, Canada (, virtual microscopy has been implemented into the histology component of its medical laboratory science programme, as well as into various aspects of its cytology programme. This implementation has corresponded with Michener's transformational curriculum revitalisation, where simulation and interprofessional collaboration have become key components in enhancing students' readiness to practice and ultimate ability to contribute to improved patient safety and patient-centred collaborative care.54 ,55 As such, the primary focus on the use of virtual microscopy at Michener was to fully integrate this technology in a competency-driven fashion, aimed at teaching microscopic tissue and stain recognition, in addition to stain, microtomy and tissue preparation troubleshooting.

Prior to the implementation of virtual microscopy at Michener, histology classes were taught using traditional light microscopes, glass slides, and PowerPoint presentations of static images. Microanatomy tests were carried out using microscopes and several glass slide collections, where students had a predetermined set of time to examine one slide before having to trade it with another classmate for a different slide. This method of assessment had many drawbacks: proper coordination was required so that all students would have a fair amount of time for each slide; students were unable to return to any slides they wanted to re-review; and breaking a slide during a test had a negative impact on the outcome of the test for all students.

The implementation of virtual microscopy has since streamlined the learning process for both instructors and students. Similar to the conventional microscope, students are able to view a glass slide specimen, being able to manoeuvre around the entire slide at various magnifications. The difference, however, is that these specimens are viewed on a computer screen rather than looking through the lens of a microscope. Lectures are now carried out in a computer lab setting using Aperio's ImageScope technology (Aperio Technologies,, where students have the option to follow along reviewing the same slide the instructor is discussing or view any one of the over 2000 available digital slides. Students can also compare and contrast several slides at once by viewing them side by side and can also easily return to a previously viewed slide at the touch of a button. The learning environment has also become much more interactive and accessible, as students are now able to access slides 24/7 to view, annotate and discuss the same slide without the need for a multi-head microscope or image projector and screen. Virtual microscopy has also improved the process of assessments by no longer fearing that glass slides may break during an assessment or having to rely on rotating glass slides among students.

Preliminary course surveys and feedback have already demonstrated a high degree of satisfaction with virtual microscopy from instructors and students from both the cytology and medical laboratory science programme. Additional preliminary investigations have also indicated that this technology may have significant valuable implications in regard to the length and type of clinical education future students may need. In an effort to further build on this knowledge, Michener has embarked on several research studies investigating student performance and skill acquisition using virtual microscopy. The ultimate goal of this unique academic case study was to realistically leverage simulation-based education in an effort to reduce the burden on clinical sites while ensuring students are better prepared for their clinical rotations. In augmenting student education, preliminary evidence suggests that clinical placement durations could be reduced, while virtual microscopy can be extended into the clinical placement to reduce dependence on traditional glass slide specimens while also providing our clinical partners and pathologists meaningful and customised exposure within their clinical environments.

Time for some more evidence

Although current evidence illustrates that virtual microscopy is beneficial for technical and professional skill building, more work is still required to reveal the full potential of this technology. The current body of evidence that does exist is limited in several ways. Most publications of virtual microscopy primarily discuss its implementation and use, and measure factors such as confidence, satisfaction and short-term skill retention.44 ,56–60 It can be argued that these measurements are ultimately somewhat subjective in the assessment of impact on patient care.61 Additionally, trials that have been conducted are usually small and thus make it difficult for results to be adequately extrapolated to larger populations or specific conclusions.29 ,32 While many studies have generated empirical data on the use of virtual microscopy in medicine,27 ,30 ,33 ,62 ,63 only a handful of publications have discussed detailed empirical evidence of its use as an educational tool.64 ,65

The next step in this area is to identify and ultimately apply best practices required for the successful implementation and utilisation of virtual microscopy in education and clinical practice. In doing this, there is a significant opportunity to directly improve learning, decrease the possibility of errors and consequently improve quality of diagnostic care for patients. It is this area that is considered the most challenging to date. Studies to assess the use of virtual microscopy should include a thorough comparison of various aspects of this technology before and after its implementation, with a focus on empirical evidence such as statistics of accuracy and technical skill acquisition. Comparative studies similar to that of Gilbertson et al,29 which compared diagnostic accuracy of pathologists using virtual microscopy, should be carried out with pathology and medical technology students, measuring fundamental skills for their own discipline, such as learning curves as well as accuracy of tissue recognition and stain identification. Further studies should also focus on the transferability of skills gained when taught using virtual slides to the application of these skills with glass slides. This is a crucial step as traditional microscopy skills are still both important and required for current clinical practice.43 Such studies may consist of taking students who have learnt a specific skill set, such as tissue recognition, using virtual slides alone and thoroughly exploring their abilities using traditional microscopes. Collaborative studies between institutions using solely glass slides and institutions using virtual slides may be an interesting and beneficial approach to such investigations.

To expand on the use of virtual slides in clinical practice, a considerable amount of work is still required before virtual slides can be utilised at the same level as glass slides. Although most studies thus far have indicated that diagnostic discrepancies identified have not had an impact on patient diagnoses, these discrepancies should still be thoroughly investigated to determine if there is a potential in similar cases for negative outcomes to occur. These investigations may need to focus on the effect of image compression on diagnostic capabilities, expanding on the work already carried out by Kalinski et al,35 as well as image quality comparisons of the same glass slide digitised using various slide scanners, as initially described by Walkowski and Szymas.66 For the latter to be feasible, there would have to be collaboration between various organisations, as most institutions only have one type of slide scanner and thus are not independently capable of making such comparisons. An added benefit from these investigations would be to help determine optimal image format and compression standards for educational and clinical purposes, including prospective standardised image formats for electronic medical records.

The ultimate goal of future research in this area should be to focus on higher level outcomes to confirm the benefits of simulation-based education and clinical practice.67 According to Kirkpatrick's model of training evaluation,68 these higher-level outcomes would include student behaviour and the ultimate results of such training, primarily enhanced readiness to practice, and improved patient safety and quality care.


Initiatives focusing on increasing the use of simulation-based tools in medical education have been embarked on to keep pace with a changing healthcare system, where increased awareness of preventable adverse events called into question the efficacy and structure of the traditional medical education model. Using simulation, students and clinicians can learn and practice specific skills in a safe, risk-free environment. The implementation of virtual microscopy as a simulation-based tool into pathology and laboratory medicine has corresponded with these changes. While there is already much literature discussing virtual microscopy, primarily its implementation into medicine, there is still a tremendous amount of research to be done to fully demonstrate the effectiveness of virtual microscopy, not only as a simulation tool in medical education, but also as a diagnostic tool directly impacting patient care. Such research should include the identification and application of valuable evaluation methods, such as comparative studies and research focusing on higher level outcomes. In doing this, there is an opportunity to enhance the delivery of pathology and laboratory science education while also revolutionising the ability to diagnose pathology collaboratively, ultimately leading to improved patient care and clinical outcomes.



  • Competing interests None.

  • Provenance and peer review Not commissioned; externally peer reviewed.