Effect of display resolution on time to diagnosis with virtual pathology slides in a systematic search task

Performing diagnoses using virtual slides can take pathologists significantly longer than with glass slides, presenting a significant barrier to the use of virtual slides in routine practice. Given the benefits in pathology workflow efficiency and safety that virtual slides promise, it is important to understand reasons for this difference and identify opportunities for improvement. The effect of display resolution on time to diagnosis with virtual slides has not previously been explored. The aim of this study was to assess the effect of display resolution on time to diagnosis with virtual slides. Nine pathologists participated in a counterbalanced crossover study, viewing axillary lymph node slides on a microscope, a 23-in 2.3-megapixel single-screen display and a three-screen 11-megapixel display consisting of three 27-in displays. Time to diagnosis and time to first target were faster on the microscope than on the single and three-screen displays. There was no significant difference between the microscope and the three-screen display in time to first target, while the time taken on the single-screen display was significantly higher than that on the microscope. The results suggest that a digital pathology workstation with an increased number of pixels may make it easier to identify where cancer is located in the initial slide overview, enabling quick location of diagnostically relevant regions of interest. However, when a comprehensive, detailed search of a slide has to be made, increased resolution may not offer any additional benefit

Scale Stain: Multi-Resolution Feature Enhancement in Pathology Visualization

Digital whole-slide images of pathological tissue samples have recently become feasible for use within routine diagnostic practice. These gigapixel sized images enable pathologists to perform reviews using computer workstations instead of microscopes. Existing workstations visualize scanned images by providing a zoomable image space that reproduces the capabilities of the microscope. This paper presents a novel visualization approach that enables filtering of the scale-space according to color preference. The visualization method reveals diagnostically important patterns that are otherwise not visible. The paper demonstrates how this approach has been implemented into a fully functional prototype that lets the user navigate the visualization parameter space in real time. The prototype was evaluated for two common clinical tasks with eight pathologists in a within-subjects study. The data reveal that task efficiency increased by 15% using the prototype, with maintained accuracy. By analyzing behavioral strategies, it was possible to conclude that efficiency gain was caused by a reduction of the panning needed to perform systematic search of the images. The prototype system was well received by the pathologists who did not detect any risks that would hinder use in clinical routine

Digital pathology in clinical use: where are we now and what is holding us back?

Whole slide imaging is being used increasingly in research applications and in frozen section, consultation and external quality assurance practice. Digital pathology, when integrated with other digital tools such as barcoding, specimen tracking and digital dictation, can be integrated into the histopathology workflow, from specimen accession to report sign-out. These elements can bring about improvements in the safety, quality and efficiency of a histopathology department. The present paper reviews the evidence for these benefits. We then discuss the challenges of implementing a fully digital pathology workflow, including the regulatory environment, validation of whole slide imaging and the evidence for the design of a digital pathology workstation

Machine learning methods for histopathological image analysis

Abundant accumulation of digital histopathological images has led to the increased demand for their analysis, such as computer-aided diagnosis using machine learning techniques. However, digital pathological images and related tasks have some issues to be considered. In this mini-review, we introduce the application of digital pathological image analysis using machine learning algorithms, address some problems specific to such analysis, and propose possible solutions.Comment: 23 pages, 4 figure

Faster than light (microscopy): superiority of digital pathology over microscopy for assessment of immunohistochemistry

YesDigital pathology offers the potential for significant benefits in diagnostic pathology, but currently the efficiency of slide viewing is a barrier to adoption. We hypothesised that presenting digital slides for simultaneous viewing of multiple sections of tissue for comparison, as in those with immunohistochemical panels, would allow pathologists to review cases more quickly. Novel software was developed to view synchronised parallel tissue sections on a digital pathology workstation. Sixteen histopathologists reviewed three liver biopsy cases including an immunohistochemical panel using the digital microscope, and three different liver biopsy cases including an immunohistochemical panel using the light microscope. The order of cases and interface was fully counterbalanced. Time to diagnosis was recorded and mean times are presented as data approximated to a normalised distribution. Mean time to diagnosis was 4 min 3 s using the digital microscope and 5 min 24 s using the light microscope, saving 1 min 21 s (95% CI 16 s to 2 min 26 s; p=0.02), using the digital microscope. Overall normalised mean time to diagnosis was 85% on the digital pathology workstation compared with 115% on the microscope, a relative reduction of 26%. With appropriate interface design, it is quicker to review immunohistochemical slides using a digital microscope than the conventional light microscope, without incurring any major diagnostic errors. As digital pathology becomes more integrated with routine clinical workflow and pathologists increase their experience of the technology, it is anticipated that other tasks will also become more time-efficient

Digitization of Pathology Labs: A Review of Lessons Learned

Pathology laboratories are increasingly using digital workflows. This has the potential of increasing lab efficiency, but the digitization process also involves major challenges. Several reports have been published describing the individual experiences of specific laboratories with the digitization process. However, a comprehensive overview of the lessons learned is still lacking. We provide an overview of the lessons learned for different aspects of the digitization process, including digital case management, digital slide reading, and computer-aided slide reading. We also cover metrics used for monitoring performance and pitfalls and corresponding values observed in practice. The overview is intended to help pathologists, IT decision-makers, and administrators to benefit from the experiences of others and to implement the digitization process in an optimal way to make their own laboratory future-proof.Comment: 22 pages, 1 figur

Digital Pathology in the Clinic: Training, Validation and Patient Safety

Digital pathology is a technology with the potential to transform the way in which histopathological diagnoses are made and cancer diagnostic services are delivered. Despite this, clinical deployment of digital slides has lagged behind research and educational uses. This thesis describes some of the key barriers to widespread clinical adoption, which largely relate to a lack of guidance and information for pathologists regarding validation, training and patient safety. The evidence base for patient safety was analysed in a novel way to provide the basis for a validation and training protocol which was trialled in real world clinical settings, and guidance documents were developed and disseminated to the clinical pathology community to help with the transition from glass slide to digital slide reporting. In Chapter 1, background information and an overview of the published literature regarding clinical use of digital pathology is provided. In the second chapter, the results of a national survey on access to and usage of digital pathology hardware, in addition to attitudes to digital pathology, is presented. One significant barrier preventing digital pathology adoption has been a lack of widespread acceptance of digital slides as a safe alternative to conventional glass slides. Historically, validation literature investigating the safety of digital pathology as an alternative to conventional light microscopy has focussed on concordance metrics of glass and digital diagnoses, when arguably, it is appreciation of discordant cases that provides the clinical pathologist with the best opportunity to evaluate the scope of safe digital practice in their specialty. Chapter 3 describes a novel study to analyse diagnostic accuracy of whole slide imaging and identify key training and educational targets for novice digital pathologists. Chapter 4 presents the validation and training protocol developed by the author for Leeds Teaching Hospitals NHS Trust, which was subsequently adopted by the Royal College of Pathologists as an example of best practise in digital pathology implementation.1 Chapter 5 describes the deployment of this protocol to train and validate the primary digital diagnosis of cohorts of breast and neuro- pathologists. Chapter 6 introduces modifications of the protocol for use for more niche reporting scenarios: frozen section diagnosis and immunohistochemistry assessment. Chapter 7 responds to concerns in the pathology community regarding accreditation of digital services, and the use of WSI for primary assessment of screening programme specimens. The body of work presented in this thesis has generated multiple peer reviewed publications which have influenced national and international digital pathology guidance. In this time period, enormous progress has been made in converting digital pathology from a niche technology for the early adopter to a mainstream topic at clinical digital pathology conferences, and the number of deployments and planned deployments in the National Health Service and beyond has risen dramatically. The use of digital slides in routine clinical practice represents a major departure from conventional light microscopy working practices, and the author hopes this work will help the pathology community maintain diagnostic quality in a time of change