Telepathology: a ten-year progress report

Smartpathk: a platform for teaching glomerulopathies using machine learning

BACKGROUND

With the emergence of the new coronavirus pandemic (COVID-19), distance learning, especially that mediated by information and digital communication technologies, has been adopted in all areas of knowledge and at all levels, including medical education. Imminently practical areas, such as pathology, have made traditional teaching based on conventional microscopy more flexible through the synergies of computational tools and image digitization, not only to improve teaching-learning but also to offer alternatives to repetitive and exhaustive histopathological analyzes. In this context, machine learning algorithms capable of recognizing histological patterns in kidney biopsy slides have been developed and validated with a view to building computational models capable of accurately identifying renal pathologies. In practice, the use of such algorithms can contribute to the universalization of teaching, allowing quality training even in regions where there is a lack of good nephropathologists. The purpose of this work is to describe and test the functionality of SmartPath^k, a tool to support teaching of glomerulopathies using machine learning. The training for knowledge acquisition was performed automatically by machine learning methods using the J48 algorithm to create a computational model of an appropriate decision tree.

RESULTS

An intelligent system, SmartPath^k, was developed as a complementary remote tool in the teaching-learning process for pathology teachers and their students (undergraduate and graduate students), showing 89,47% accuracy using machine learning algorithms based on decision trees.

CONCLUSION

This artificial intelligence system can assist in teaching renal pathology to increase the training capacity of new medical professionals in this area.

Diagnostic interobserver variability in Crohn's disease- and ulcerative colitis-associated dysplasia: a multicenter digital survey from the IG-IBD Pathologists Group

BACKGROUND

Crohn's disease (CD) and ulcerative colitis, two forms of inflammatory bowel disease (IBD), are chronic and relapsing conditions of the gastrointestinal tract both characterized by long lasting chronic inflammation and increased risk of dysplasia and colorectal cancer (CRC). The aim of our study was to evaluate the interobserver agreement about IBD-associated dysplasia among pathologists belonging to the Italian Group for Inflammatory Bowel Diseases (IG-IBD P).

METHODS

The present multicenter survey was performed using telepathology, supported by an open source E-learning platform. Biopsy specimens from 30 colonoscopies and from 20 patients were included. The glass slides of any case, including clinical and endoscopic data, were digitalized and uploaded on the E-learning platform. All the digital slides were grouped in 54 diagnostic "blocks". Blinded histopathological evaluation on all the digital slides was performed by 20 gastrointestinal pathologists. Closed-ended questions about (1) the occurrence of IBD; (2) the classification of IBD (as UC or CD); (3) the presence of active versus quiescent disease; (4) the presence of dysplasia; (5) the possible association of dysplasia with the sites of disease (dysplasia-associated lesion or mass-DALM vs adenoma-like mass-ALM); (6) the grading of dysplasia according to the ECCO guidelines (negative, indefinite, low grade, high grade categories) and (7) the presence of associated serrated features, were proposed in each case. Inter-observer agreement was evaluated by mean agreement percentage and kappa statistic, when suitable.

RESULTS

The diagnosis of IBD was confirmed in 19 of 20 patients, 17 of 19 being classified as UC, 2 as CD. The mean interobserver agreement percentages about (1) the evidence of IBD, (2) the presence of either UC or CD and (3) the activity grading resulted to be 80%, 69% and 86%, respectively. Dysplasia was detected in 8/20 patients, with moderate agreement between pathologists (mean 72%, k 0.48). Particularly, low grade dysplasia was found in 13 biopsies (combined k 0.38), whereas high grade dysplasia in 8 (combined k 0.47). When the endoscopic and histopathological data were combined, features consistent with DALM were found in 6 of 20 patients with low grade dysplasia and those consistent with ALM in 2 patients with low grade dysplasia in a single biopsy (mean agreement: 86%). An associated serrated pattern was discovered in 4 patients (7 biopsies).

CONCLUSIONS

Our study showed moderate interobserver agreement about the histopathological detection and classification of IBD-associated dysplasia. Further efforts should be undertaken to integrate the histopathological data with both the ancillary tests and molecular investigations.

Pathology and Telepathology Methods in the Child Health and Mortality Prevention Surveillance Network

This manuscript describes the Child Health and Mortality Prevention Surveillance (CHAMPS) network approach to pathologic evaluation of minimally invasive tissue sampling (MITS) specimens, including guidelines for histopathologic examination and further diagnostics with special stains, immunohistochemistry, and molecular testing, as performed at the CHAMPS Central Pathology Laboratory (CPL) at the Centers for Disease Control and Prevention, as well as techniques for virtual discussion of these cases (telepathology) with CHAMPS surveillance locations. Based on review of MITS from the early phase of CHAMPS, the CPL has developed standardized histopathology-based algorithms for achieving diagnoses from MITS and telepathology procedures in conjunction with the CHAMPS sites, with the use of whole slide scanners and digital image archives, for maximizing concurrence and knowledge sharing between site and CPL pathologists. These algorithms and procedures, along with lessons learned from initial implementation of these approaches, guide pathologists at the CPL and CHAMPS sites through standardized diagnostics of MITS cases, and allow for productive, real-time case discussions and consultations.

The future of pathology is digital

Information, archives, and intelligent artificial systems are part of everyday life in modern medicine. They already support medical staff by mapping their workflows with shared availability of cases' referral information, as needed for example, by the pathologist, and this support will be increased in the future even more. In radiology, established standards define information models, data transmission mechanisms, and workflows. Other disciplines, such as pathology, cardiology, and radiation therapy, now define further demands in addition to these established standards. Pathology may have the highest technical demands on the systems, with very complex workflows, and the digitization of slides generating enormous amounts of data up to Gigabytes per biopsy. This requires enormous amounts of data to be generated per biopsy, up to the gigabyte range. Digital pathology allows a change from classical histopathological diagnosis with microscopes and glass slides to virtual microscopy on the computer, with multiple tools using artificial intelligence and machine learning to support pathologists in their future work.

Invention and Early History of Telepathology (1985-2000)

This narrative-based paper provides a first-person account of the early history of telepathology (1985–2000) by the field's inventor, Ronald S. Weinstein, M. D. During the 1980s, Dr. Weinstein, a Massachusetts General Hospital-trained pathologist, was director of the Central Pathology Laboratory (CPL) for the National Cancer Institute-funded National Bladder Cancer Project, located at Rush Medical College in Chicago, IL. The CPL did post therapy revalidations of surgical pathology and cytopathology diagnoses before outcomes of the completed clinical trials were published. The CPL reported that interobserver variability was invalidating inclusion of dozens of treated bladder cancer patients in published reports on treatment outcomes. This problem seemed ripe for a technology-assisted solution. In an effort to solve the interobserver variability problem, Dr. Weinstein devised a novel solution, dynamic-robotic telepathology, that would potentially enable CPL uropathologists to consult on distant uropathology cases in real-time before their assignment to urinary bladder cancer, tumor stage, and grade-specific clinical trials. During the same period, universities were ramping up their support for faculty entrepreneurism and creating in-house technology transfer organizations. Dr. Weinstein recognized telepathology as a potential growth industry. He and his sister, Beth Newburger, were a successful brother–sister entrepreneur team. Their PC-based education software business, OWLCAT™, had just been acquired by Digital Research Inc., a leading software company, located in California. With funding from the COMSAT Corporation, a publically traded satellite communications company, the Weinstein-Newburger team brought the earliest dynamic-robotic telepathology systems to market. Dynamic-robotic telepathology became a dominant telepathology technology in the late 1990s. Dr. Weinstein, a serial entrepreneur, continued to innovate and, with a team of optical scientists at The University of Arizona's College of Optical Sciences, developed the first sub-1-min whole-slide imaging system, the DMetrix DX-40 scanner, in the early 2000s.

Interobserver Agreement in the Diagnosis of Inflammatory Bowel Disease-Associated Neoplasia in China in Comparison to Subspecialized American Gastrointestinal Pathologists

Background

The aim of this study was to evaluate the interobserver variability in diagnosing inflammatory bowel disease (IBD)-associated neoplasia among practicing pathologists from China using telepathology, a practice of remote diagnostic consultation increasingly used nationally and internationally, and its comparison with the interpretation of subspecialized gastrointestinal (GI) pathologists from the United States (US).

Methods

Eight GI pathologists from the US and 4 pathologists from China with an interest in GI pathology participated in this study. A total of 50 colonic biopsies from patients with a clinical history of IBD from 8 medical centers in China were included. All microscopic slides in each case were digitized using an Aperio system. One pathologist (XL) reviewed the digitized full-slide images, and selected areas of interest were captured at low, medium, and high magnifications at a resolution of 1712 × 1072 pixels and saved as tagged image file format (TIFF) files on read-only DVD. Each pathologist evaluated the images and selected the most appropriate diagnostic category for each case (negative, indefinite, low-grade dysplasia [LGD], high-grade dysplasia [HGD], and carcinoma). A Fleiss' kappa coefficient (K) analysis was performed to determine interobserver agreement and the agreement of each pathologist from China with the consensus diagnosis (defined as diagnostic agreement by at least 4 participating US GI pathologists).

Results

There was substantial interobserver agreement among 4 pathologists from China on the interpretation of IBD-associated neoplasia (kappa value 0.68, 95% confidence interval: 0.56-0.78). A consensus diagnosis included negative (n = 22), LGD (n = 22), HGD (n = 3), carcinoma (n = 2), and indefinite for dysplasia (n = 1). Using consensus diagnoses as references, the agreement between each pathologist from China and the consensus diagnosis was substantial with kappa values ranging from 0.75 to 0.80.

Conclusions

This study reveals substantial interobserver agreement for the interpretation of colonic neoplasia in IBD using digitized images among Chinese pathologists as well as between each Chinese pathologist and a consensus diagnosis generated by US GI pathologists.

Evaluation of photoshop based image analysis in cytologic diagnosis of pleural fluid in comparison with conventional modalities

BACKGROUND

The aim of this study is to investigate and compare the results of digital image analysis in pleural effusion cytology samples with conventional modalities.

MATERIALS AND METHODS

In this cross-sectional study, 53 pleural fluid cytology smears from Qaem hospital pathology department, located in Mashhad, Iran were investigated. Prior to digital analysis, all specimens were evaluated by two pathologists and categorized into three groups as: benign, suspicious, and malignant. Using an Olympus microscope and Olympus DP3 digital camera, digital images from cytology slides were captured. Appropriate images (n = 130) were separately imported to Adobe Photoshop CS5 and parameters including area and perimeter, circularity, Gray Value mean, integrated density, and nucleus to cytoplasm area ratio were analyzed.

RESULTS

Gray Value mean, nucleus to cytoplasm area ratio, and circularity showed the best sensitivity and specificity rates as well as significant differences between all groups. Also, nucleus area and perimeter showed a significant relation between suspicious and malignant groups with benign group. Whereas, there was no such difference between suspicious and malignant groups.

CONCLUSION

We concluded that digital image analysis is welcomed in the field of research on pleural fluid smears as it can provide quantitative data to apply various comparisons and reduce interobserver variation which could assist pathologists to achieve a more accurate diagnosis.

The Empirical Foundations of Telepathology: Evidence of Feasibility and Intermediate Effects

INTRODUCTION

Telepathology evolved from video microscopy (i.e., "television microscopy") research in the early 1950s to video microscopy used in basic research in the biological sciences to a basic diagnostic tool in telemedicine clinical applications. Its genesis can be traced to pioneering feasibility studies regarding the importance of color and other image-based parameters for rendering diagnoses and a series of studies assessing concordance of virtual slide and light microscopy diagnoses. This article documents the empirical foundations of telepathology.

METHODS

A selective review of the research literature during the past decade (2005-2016) was conducted using robust research design and adequate sample size as criteria for inclusion.

CONCLUSIONS

The evidence regarding feasibility/acceptance of telepathology and related information technology applications has been well documented for several decades. The majority of evidentiary studies focused on intermediate outcomes, as indicated by comparability between telepathology and conventional light microscopy. A consistent trend of concordance between the two modalities was observed in terms of diagnostic accuracy and reliability. Additional benefits include use of telepathology and whole slide imaging for teaching, research, and outreach to resource-limited countries. Challenges still exist, however, in terms of use of telepathology as an effective diagnostic modality in clinical practice.

Validation of diagnostic accuracy with whole-slide imaging compared with glass slide review in dermatopathology

BACKGROUND

Teledermatopathology has evolved from static images to whole slide imaging (WSI), which allows for remote viewing and manipulation of tissue sections. Previous studies of WSI in teledermatopathology predated College of American Pathologists (CAP) telepathology validation guidelines.

OBJECTIVE

We conducted a comprehensive retrospective WSI validation study of routine dermatopathology cases, adhering to CAP guidelines.

METHOD

In all, 181 consecutive cases arranged into 3 categories (inflammatory, melanocytic, nonmelanocytic proliferations) were reviewed by 3 board-certified dermatopathologists via traditional microscopy (TM) and WSI. Intraobserver (TM vs WSI), TM intraobserver and interobserver (TM vs TM), and WSI interobserver (WSI vs WSI) concordance was interpreted using a 3-tier system.

RESULTS

TM versus WSI intraobserver concordance (86.9%; 95% confidence interval [CI] 83.7-89.6) did not differ from TM versus TM intraobserver concordance (90.3%; 95% CI 86.7-93.1) or interobserver concordance (WSI: 89.9%; 95% CI 87.0-92.2, and TM: 89.5%; 95% CI 86.5-91.9). Melanocytic proliferations had the lowest TM versus WSI intraobserver concordance (75.6%; 95% CI 68.5-81.5), whereas inflammatory lesions had the highest TM versus WSI intraobserver concordance (96.1%; 95% CI 91.8-98.3). Nonmelanocytic proliferations had an intraobserver concordance of 89.1% (95% CI 83.4-93.0).

LIMITATIONS

Efficiency and other logistical WSI parameters were not evaluated.

CONCLUSION

Intraobserver and interobserver diagnostic concordance between WSI and TM was equivalent. Therefore, WSI appears to be a reliable diagnostic modality for dermatopathology.

Histopathological grading of breast ductal carcinoma in situ: validation of a web-based survey through intra-observer reproducibility analysis

BACKGROUND

Histopathological grading diagnosis of ductal carcinoma in situ (DCIS) of the breast may be very difficult even for experts, and it is important for therapeutic decisions. The challenge may be due to the inaccurate and/or subjective application of the diagnosis criteria. The aim of this study was to investigate the intra-observer agreement between a traditional method and a developed web-based questionnaire for scoring breast DCIS.

METHODS

A cross-sectional study was carried out to evaluate the diagnostic agreement of an electronic questionnaire and its point scoring system with the subjective reading of digital images for 3 different DCIS grading systems: Holland, Van Nuys and modified Black nuclear grade system. Three pathologists analyzed the same set of digitized images from 43 DCIS cases using two different web-based programs. In the first phase, they accessed a website with a newly created questionnaire and scoring system developed to allow the determination of the histological grade of the cases. After at least 6 months, the pathologists read again the same images, but without the help of the questionnaire, indicating subjectively the diagnoses. The intra-observer agreement analysis was employed to validate this innovative web-based survey.

RESULTS

Overall, diagnostic reproducibility was similar for all histologic grading classification systems, with kappa values of 0.57 ± 0.10, 0.67 ± 0.09 and 0.67 ± 0.09 for Holland, Van Nuys classification and modified Black nuclear grade system respectively. Only two 2-step diagnostic disagreements were found, one for Holland and another for Van Nuys. Both cases were superestimated by the web-based survey.

CONCLUSION

The diagnostic agreement between the web-based questionnaire and a traditional method, both using digital images, is moderate to good for Holland, Van Nuys and modified Black nuclear grade system. The use of a scoring point system does not appear to pose a major risk of presenting large (2-step) diagnostic disagreements. These findings indicate that the use of this point scoring system in this web-based survey to grade objectively DCIS lesions is a useful diagnostic tool.

Overview of Telepathology

Telepathology is the practice of remote pathology using telecommunication links to enable the electronic transmission of digital pathology images. Telepathology can be used for remotely rendering primary diagnoses, second opinion consultations, quality assurance, education, and research purposes. The use of telepathology for clinical patient care has been limited mostly to large academic institutions. Barriers that have limited its widespread use include prohibitive costs, legal and regulatory issues, technologic drawbacks, resistance from pathologists, and above all a lack of universal standards. This article provides an overview of telepathology technology and applications.

World's first telepathology experiments employing WINDS ultra-high-speed internet satellite, nicknamed "KIZUNA"

Background:

Recent advances in information technology have allowed the development of a telepathology system involving high-speed transfer of high-volume histological figures via fiber optic landlines. However, at present there are geographical limits to landlines. The Japan Aerospace Exploration Agency (JAXA) has developed the “Kizuna” ultra-high speed internet satellite and has pursued its various applications. In this study we experimented with telepathology in collaboration with JAXA using Kizuna. To measure the functionality of the Wideband InterNet working engineering test and Demonstration Satellite (WINDS) ultra-high speed internet satellite in remote pathological diagnosis and consultation, we examined the adequate data transfer speed and stability to conduct telepathology (both diagnosis and conferencing) with functionality, and ease similar or equal to telepathology using fiber-optic landlines.

Materials and Methods:

We performed experiments for 2 years. In year 1, we tested the usability of the WINDS for telepathology with real-time video and virtual slide systems. These are state-of-the-art technologies requiring massive volumes of data transfer. In year 2, we tested the usability of the WINDS for three-way teleconferencing with virtual slides. Facilities in Iwate (northern Japan), Tokyo, and Okinawa were connected via the WINDS and voice conferenced while remotely examining and manipulating virtual slides.

Results:

Network function parameters measured using ping and Iperf were within acceptable limits. However; stage movement, zoom, and conversation suffered a lag of approximately 0.8 s when using real-time video, and a delay of 60-90 s was experienced when accessing the first virtual slide in a session. No significant lag or inconvenience was experienced during diagnosis and conferencing, and the results were satisfactory. Our hypothesis was confirmed for both remote diagnosis using real-time video and virtual slide systems, and also for teleconferencing using virtual slide systems with voice functionality.

Conclusions:

Our results demonstrate the feasibility of ultra-high-speed internet satellite networks for use in telepathology. Because communications satellites have less geographical and infrastructural requirements than landlines, ultra-high-speed internet satellite telepathology represents a major step toward alleviating regional disparity in the quality of medical care.

The history of pathology informatics: A global perspective

Pathology informatics has evolved to varying levels around the world. The history of pathology informatics in different countries is a tale with many dimensions. At first glance, it is the familiar story of individuals solving problems that arise in their clinical practice to enhance efficiency, better manage (e.g., digitize) laboratory information, as well as exploit emerging information technologies. Under the surface, however, lie powerful resource, regulatory, and societal forces that helped shape our discipline into what it is today. In this monograph, for the first time in the history of our discipline, we collectively perform a global review of the field of pathology informatics. In doing so, we illustrate how general far-reaching trends such as the advent of computers, the Internet and digital imaging have affected pathology informatics in the world at large. Major drivers in the field included the need for pathologists to comply with national standards for health information technology and telepathology applications to meet the scarcity of pathology services and trained people in certain countries. Following trials by a multitude of investigators, not all of them successful, it is apparent that innovation alone did not assure the success of many informatics tools and solutions. Common, ongoing barriers to the widespread adoption of informatics devices include poor information technology infrastructure in undeveloped areas, the cost of technology, and regulatory issues. This review offers a deeper understanding of how pathology informatics historically developed and provides insights into what the promising future might hold.

OBJECT-RELATIONAL QUERIES INTO MULTIDIMENSIONAL DATABASES WITH THE ACTIVE DATA REPOSITORY

As computational power and storage capacity increase, processing and analyzing large volumes of multi-dimensional datasets play an increasingly important role in many domains of scientific research. Scientific applications that make use of very large scientific datasets have several important characteristics: datasets consist of complex data and are usually multi-dimensional; applications usually retrieve a subset of all the data available in the dataset; various application-specific operations are performed on the data items retrieved. Such applications can be supported by object-relational database management systems (OR-DBMSs). In addition to providing functionality to define new complex datatypes and user-defined functions, an OR-DBMS for scientific datasets should contain runtime support that will provide optimized storage for very large datasets and an execution environment for user-defined functions involving expensive operations. In this paper we describe an infrastructure, the Active Data Repository (ADR), which provides framework for building databases that enables integration of storage, retrieval and processing of multi-dimensional datasets on a parallel machine. The system architecture of ADR provides the functionality required from runtime support for an OR-DBMS that stores and processes scientific multi-dimensional datasets. We present the system architecture of the ADR, and experimental performance results for three applications implemented using ADR.

Telecytology in East Africa: a feasibility study of forty cases using a static imaging system

We conducted a pilot study to assess the feasibility of telecytology as a diagnostic tool in difficult cases originating from a hospital in East Africa. Forty cytology cases considered difficult by a referring pathologist were posted on a telepathology website. Six pathologists independently assessed the static images. Telecytology diagnoses were compared with the consensus diagnoses made on glass slides and also with the histogical diagnoses when available. The diagnostic agreement of the six pathologists was 71-93% and tended to be higher for pathologists with more experience. Reasons for discordance included poor image quality, presence of diagnostic cells in thick areas of smears, sampling bias and screening errors. The consensus diagnoses agreed with histological diagnoses in all 17 cases in which a biopsy was performed. Diagnostic accuracy rates (i.e. telecytology diagnosis vs. histological diagnosis) for individual pathologists were 65-88%. To ensure diagnostic accuracy both referring and consulting pathologists must have adequate training in cytology, image acquisition and image-based diagnosis and the diagnostic questions of importance must be clearly communicated by the referring pathologist when posting a case.

Feasibility and diagnostic accuracy of Internet-based dynamic telepathology between Uganda and Germany

We assessed the feasibility and diagnostic accuracy of Internet-based telepathology compared with conventional microscopic examination. A total of 96 cases from the routine workload of the Department of Pathology at the Mulago Hospital in Uganda were examined by robotic telemicroscopy via the Internet at the Fuerth Hospital in Germany. The telepathology diagnoses were compared with those of conventional microscopy. Email and Skype telephony were used to exchange clinical and diagnostic information. The reference diagnosis (gold standard) was established by consensus between two or more experienced pathologists using both conventional microscopy and telemicroscopy; immunohistochemistry was used whenever it was necessary. It took approximately 30 min for a pathologist to learn to use the telepathology system and 4–25 min to read a case remotely. Internet speed was the main limiting factor. The images were of good quality and the pathologist at the remote site was able to navigate through the slide and change the magnification as necessary. In 92 of the specimens (97%), the pathologists at the two hospitals agreed exactly about the diagnosis. Agreement overall was moderate (kappa = 0.39). The discordant diagnoses were attributed to factors related to diseases morphologically difficult to diagnose, such as soft tissue sarcomas and primitive tumours. Internet-based conferencing systems offer an inexpensive method of obtaining a primary diagnosis by telepathology and consulting on cases that require subspecialty expertise.

Clinical examination and validation of primary diagnosis in anatomic pathology using whole slide digital images

CONTEXT

Novel anatomic pathology technologies allow pathologists to digitally view and diagnose cases. Although digital pathology advocates champion its strengths and move to integrate it into practice and workflow, the capabilities and limitations of digital slides have not been fully investigated.

OBJECTIVES

To estimate intrapathologist diagnostic discrepancy between glass and digital slides and to determine pathologists' diagnostic certainty when diagnosing with the 2 formats.

DESIGN

Intrapathologist diagnostic consistency between glass and digital slides was measured. Three pathologists diagnosed 101 cases digitally and with corresponding glass slides. Discrepancies between formats were evaluated, and diagnostic precision and certainty were compared.

RESULTS

A total of 606 diagnoses were evaluated in pairs (202 per pathologist). Seven cases did not transfer to the database and were eliminated from further study. We report no discrepancies between media in 75%, 87%, and 83% of the cases diagnosed by the 3 pathologists, respectively; significant discrepancies were identified in 3%, 3%, and 7% of cases by each pathologist. In total, we identified significant clinical and therapeutic discrepancies in 13 of 296 cases (4.4%). The certainty values provided by each pathologist were similar between formats.

CONCLUSIONS

This study did not detect significant differences between diagnoses based on digital and glass slides. We believe that this study further supports the integration of digital slides into pathology workflow, particularly considering the low rate of discrepancy documented here.

Transnational telepathology consultations using a basic digital microscope: experience in the Italy-Slovenjia INTERREG project "patient without borders"

Background

In recent years, a number of technological advancements started to modify the long standing appearance and functionalities of traditional optical microscopes used in Pathology and other medical fields. In fact, at present many new tools for microscopical visualization exist that are based on digital imaging, robotization, and remote communication. Such tools are typically adopted in activities ranging from education to telediagnosis to remote consultation.

Present paper describes the features of a basic digital microscope that has been tested to verify its performance for occasional remote consultation inside an international project between Italy and Slovenija, funded by Interreg initiative of the European Regional Development Fund.

Methods

The system is composed by a pair of digital microscopes (Leica DMD108, Leitz Microsystems, Wetzlar, Germany) associated to a high resolution videoconferencing systems (Tandberg 990, Lysaker, Norway). The systems are connected through the Internet. Sixty histology and cytology cases have been collaboratively diagnosed between two Pathology Institutes to verify the diagnostic performance of the system, regarding the image quality point of view as well as time needed for diagnosis. The system has also been tested for compatibility with standard videoconferencing software.

Results

No discrepancies between local and remote diagnoses have been identified, with diagnosis time reasonably close to typical microscope observation times. Time needed for most operations is not far from that needed on a traditional microscope, except for startup.

Conclusions

The system can be considered usable as a standard microscope, and also for occasional remote consultations.

Telepathology for patient care: what am I getting myself into?

The vast advancements in telecommunications and converting medical information to a digital format have increased the number of applications within telemedicine. Telepathology, in simplest terms, is the practice of formally rendering a pathologic diagnosis based upon examination of an image rather than of a glass slide through traditional microscopy. The use of telepathology for clinical patient care has so far been limited to relatively few large academic institutions. Although a number of challenges remain, there is increasing demand for the use of information technology in pathology as a whole owing to the expansion of health care networks and the opportunity to enhance the quality of service delivered to patients. The software used to acquire, display, and manage digital images for clinical patient care may be subject to national and federal regulations just as is any other electronic information system. Despite the barriers, telepathology systems possess the capability to help manage pathology cases on a global scale, improve laboratory workload distribution, increase standardization of practice and enable new classes of ancillary studies to facilitate diagnosis and education even in the most remote parts of the earth.

Informatics for practicing anatomical pathologists: marking a new era in pathology practice

Informatics can be defined as using highly advanced technologies to improve patient diagnosis or management. Pathology informatics had evolved as a response to the overwhelming amount of information that was available, in an attempt to better use and maintain them. The most commonly used tools of informatics can be classified into digital imaging, telepathology, as well as Internet and electronic data mining. Digital imaging is the storage of anatomical pathology information, either gross pictures or microscopic slides, in an electronic format. These images can be used for education, archival, diagnosis, and consultation. Virtual microscopy is the more advanced form of digital imaging with enhanced efficiency and accessibility. Telepathology is now increasingly becoming a useful tool in anatomical pathology practice. Different types of telepathology communications are available for both diagnostic and consultation services. The spectrum of applications of informatics in the field of anatomical pathology is broad and encompasses medical education, clinical services, and pathology research. Informatics is now settling on solid ground as an important tool for pathology teaching, with digital teaching becoming the standard tool in many institutions. After a slow start, we now witness the transition of informatics from the research bench to bedside. As we are moving into a new era of extensive pathology informatics utilization, several challenges have to be addressed, including the cost of the new technology, legal issues, and resistance of pathologists. It is clear from the current evidence that pathology informatics will continue to grow and have a major role in the future of our specialty. However, it is also clear that it is not going to fully replace the human factor or the regular microscope.

Virtual slide telepathology enables an innovative telehealth rapid breast care clinic

An innovative telemedicine-enabled rapid breast care service is described that bundles telemammography, telepathology, and teleoncology services into a single day process. The service is called the UltraClinics Process. Since the core services are at four different physical locations a challenge has been to obtain STAT second opinion readouts on newly diagnosed breast cancer cases. In order to provide same day QA re-review of breast surgical pathology cases, a DMetrix DX-40 ultrarapid virtual slide scanner (DMetrix, Inc., Tucson, AZ) was installed at the participating laboratory. Glass slides of breast cancer and breast hyperplasia cases were scanned the same day the slides were produced by the University Physicians Healthcare Hospital histology laboratory. Virtual slide telepathology was used for STAT quality assurance readouts at University Medical Center, 6 miles away. There was complete concurrence with the primary diagnosis in 139 (90.3%) of cases. There were 4 (2.3%) major discrepancies, which would have resulted in a different therapy and 3 (1.9%) minor discrepancies. Three cases (1.9%) were deferred for immunohistochemistry. In 2 cases (1.3%), the case was deferred for examination of the glass slides by the reviewing pathologists at University Medical Center. We conclude that the virtual slide telepathology QA program found a small number of significant diagnostic discrepancies. The virtual slide telepathology program service increased the job satisfaction of subspecialty pathologists without special training in breast pathology, assigned to cover the general surgical pathology service at a small satellite university hospital.

Overview of telepathology, virtual microscopy, and whole slide imaging: prospects for the future

Telepathology, the practice of pathology at a long distance, has advanced continuously since 1986. Today, fourth-generation telepathology systems, so-called virtual slide telepathology systems, are being used for education applications. Both conventional and innovative surgical pathology diagnostic services are being designed and implemented as well. The technology has been commercialized by more than 30 companies in Asia, the United States, and Europe. Early adopters of telepathology have been laboratories with special challenges in providing anatomic pathology services, ranging from the need to provide anatomic pathology services at great distances to the use of the technology to increase efficiency of services between hospitals less than a mile apart. As to what often happens in medicine, early adopters of new technologies are professionals who create model programs that are successful and then stimulate the creation of infrastructure (ie, reimbursement, telecommunications, information technologies, and so on) that forms the platforms for entry of later, mainstream, adopters. The trend at medical schools, in the United States, is to go entirely digital for their pathology courses, discarding their student light microscopes, and building virtual slide laboratories. This may create a generation of pathology trainees who prefer digital pathology imaging over the traditional hands-on light microscopy. The creation of standards for virtual slide telepathology is early in its development but accelerating. The field of telepathology has now reached a tipping point at which major corporations now investing in the technology will insist that standards be created for pathology digital imaging as a value added business proposition. A key to success in teleradiology, already a growth industry, has been the implementation of standards for digital radiology imaging. Telepathology is already the enabling technology for new, innovative laboratory services. Examples include STAT QA surgical pathology second opinions at a distance and a telehealth-enabled rapid breast care service. The innovative bundling of telemammography, telepathology, and teleoncology services may represent a new paradigm in breast care that helps address the serious issue of fragmentation of breast cancer care in the United States and elsewhere. Legal and regulatory issues in telepathology are being addressed and are regarded as a potential catalyst for the next wave of telepathology advances, applications, and implementations.

Virtual slide telepathology for an academic teaching hospital surgical pathology quality assurance program

Virtual slide telepathology is an important potential tool for providing re-review of surgical pathology cases as part of a quality assurance program. The University of Arizona pathology faculty has implemented a quality assurance program between 2 university hospitals located 6 miles apart. The flagship hospital, University Medical Center (UMC), in Tucson, AZ, handles approximately 20 000 surgical pathology specimens per year. University Physicians Healthcare Hospital (UPHH) at Kino Campus has one tenth the volume of surgical pathology cases. Whereas UMC is staffed by 10 surgical pathologists, UPHH is staffed daily by a single part-time pathologist on a rotating basis. To provide same-day quality assurance re-reviews of cases, a DMetrix DX-40 ultrarapid virtual slide scanner (DMetrix, Inc, Tucson, AZ) was installed at the UPHH in 2005. Since then, glass slides of new cases of cancer and other difficult cases have been scanned the same day the slides are produced by the UPHH histology laboratory. The pathologist at UPHH generates a provisional written report based on light microscopic examination of the glass slides. At 2:00 pm each day, completed cases from UPHH are re-reviewed by staff pathologists, pathology residents, and medical students at the UMC using the DMetrix Iris virtual slide viewer. The virtual slides are viewed on a 50-in plasma monitor. Results are communicated with the UPHH laboratory by fax. We have analyzed the results of the first 329 consecutive quality assurance cases. There was complete concordance with the original UPHH diagnosis in 302 (91.8%) cases. There were 5 (1.5%) major discrepancies, which would have resulted in different therapy and/or management, and 10 (3.0%) minor discrepancies. In 6 cases (1.8%), the diagnosis was deferred for examination of the glass slides by the reviewing pathologists at UMC, and the diagnosis of another 6 (1.8%) cases were deferred pending additional testing, usually immunohistochemistry. Thus, the quality assurance program found a small number of significant diagnostic discrepancies. We also found that implementation of a virtual slide telepathology quality assurance service improved the job satisfaction of academic subspecialty pathologists assigned to cover on-site surgical pathology services at a small, affiliated university hospital on a rotating part-time basis. These findings should be applicable to some community hospital group practices as well.

Happenings in Histopathology – A Post-World War II Perspective

There have been several important developments in the practice of histopathology since World War II; those reviewed in this lecture are grouped under 4 headings: new techniques (cytopathology, electron microscopy, immunohistochemistry and molecular pathology), organisational issues (recruitment, training and certification, subspecialties, quality control and consultations), ethical and legal issues (service costs, and the ownership and uses of biopsy tissues) and globalisation (international associations, standardised classification and nomenclature, and telepathology). Advances in the fields of molecular pathology and telepathology are expected to have the greatest impact on the practice of pathology in the next decade. Key words: Anatomic pathology, Organisation, Globalisation, Telepathology

Spatial resolution requirements for acquisition of the virtual screening slide for digital whole-specimen breast histopathology

We examined the effect of lateral spatial resolution and reader specialty on the accuracy of detection of breast cancer. The motivation for this pilot study was the need to acquire and display very large data sets in whole-specimen 3D digital breast histopathology imaging. The ultimate goal is to determine the minimum resolution adequate for detection of malignancy. Twenty-three histologic slides were selected from breast pathology cases and digitized at 2 sampling distances (3.2 and 1.9 microm pixels). Images were viewed by 14 pathologists, of whom 5 had breast pathology as their primary specialty. The readers assessed the likelihood of malignancy on a 5-point Likert scale, and provided a provisional diagnosis. For the detection task, sensitivity, specificity, overall accuracy of detection, and area under the receiver-operator curve were calculated. An overall diagnostic score, and scores grouped by malignancy type, were also computed. Outcome measures were examined for significant resolution and specialty effects. Increasing the lateral resolution significantly improved accuracy in diagnosis (P=.004) but no effect was found for detection. Breast specialists achieved significantly higher scores for all outcome measures except specificity. Differences in performance between the 2 groups of readers tended to be greater for the diagnostic task compared to detection, especially at the higher resolution. However, specimen coverage may also be a significant factor. Factors related to the readers may have also affected performance in this study. Based on these results, a more comprehensive study should examine pixel sizes between 0.7 and 1.9 microm.

Telepathology for Intraoperative Neuropathologic Consultations at an Academic Medical Center: A 5-Year Report

Telepathology is an attractive solution for providing neuropathologic intraoperative expertise to geographically diverse hospitals from a center of excellence. To date, few reports specifically address the feasibility of such a system for intraoperative neuropathology specimens. The University of Pittsburgh Medical Center is a 20-hospital system in Southwest Pennsylvania in which the pathology department has adopted a subspecialty "centers of excellence" method of managing cases. The Division of Neuropathology is physically located at 1 hospital but provides neuropathologic expertise to the entire system. Adult neurosurgery is currently limited to 2 hospitals separated by 18 city blocks. We describe our experience in providing remote intraoperative neuropathologic consultations over a 5-year period, from 2002 to 2006. Several approaches are discussed, with emphasis on the current system and the evolution of imaging technology. Diagnostic outcomes are compared among >400 telepathology cases and >1,200 conventional intraoperative cases. Current technology is capable of facilitating teleneuropathologic intraoperative diagnoses in a timely manner, with accuracy rates comparable to those for conventional methods. However, the practice of providing these remote consultations requires a sophisticated and technologically advanced environment along with substantial planning, communication, and training of both pathologists and pathology assistants.

Eye-movement study and human performance using telepathology virtual slides. Implications for medical education and differences with experience

A core skill in diagnostic pathology is light microscopy. Remarkably little is known about human factors that affect the proficiency of pathologists as light microscopists. The cognitive skills of pathologists have received relatively little attention in comparison with the large literature on human performance studies in radiology. One reason for this lack of formal visual search studies in pathology has been the physical restrictions imposed by the close positioning of a microscope operator's head to the microscope's eyepieces. This blocks access to the operator's eyes and precludes assessment of the microscopist's eye movements. Virtual slide microscopy now removes this barrier and opens the door for studies on human factors and visual search strategies in light microscopy. The aim of this study was to assess eye movements of medical students, pathology residents, and practicing pathologists examining virtual slides on a digital display monitor. Whole histopathology glass slide digital images, so-called virtual slides, of 20 consecutive breast core biopsy cases were used in a retrospective study. These high-quality virtual slides were produced with an array-microscope equipped DMetrix DX-40 ultrarapid virtual slide processor (DMetrix, Tucson, Ariz). Using an eye-tracking device, we demonstrated for the first time that when a virtual slide reader initially looks at a virtual slide his or her eyes are very quickly attracted to regions of interest (ROIs) within the slide and that these ROIs are likely to contain diagnostic information. In a matter of seconds, critical decisions are made on the selection of ROIs for further examination at higher magnification. We recorded: (1) the time virtual slide readers spent fixating on self-selected locations on the video monitor; (2) the characteristics of the ways the eyes jumped between fixation locations; and (3) x and y coordinates for each virtual slide marking the sites the virtual slide readers manually selected for zooming to higher ROI magnifications. We correlated the locations of the visually selected fixation locations and the manually selected ROIs. Viewing profiles were identified for each group. Fully trained pathologists spent significantly less time (mean, 4.471 seconds) scanning virtual slides when compared to pathology residents (mean, 7.148 seconds) or medical students (mean, 11.861 seconds), but had relatively prolonged saccadic eye movements (P < .0001). Saccadic eye movements are defined as eye movements between fixation locations. On the other hand, the pathologists spent significantly more time than trainees dwelling on the 3 locations they subsequently chose for zooming. Unlike either the medical students or the residents, the pathologists frequently choose areas for viewing at higher magnification outside of areas of foveal (central) vision. Eye movement studies of scanning pathways (scan paths) may be useful for developing eye movement profiles for individuals and for understanding the difference in performances between novices and experts. They may also be useful for developing new visual search strategies for rendering diagnoses on telepathology virtual slides.

Static telepathology in cancer institute of Tehran university: report of the first academic experience in Iran

Telepathology is the practice of pathology, which allows quick and timely access to an expert opinion at a distance. We analyzed our new experience in cancer Institute of Tehran University of Medical Sciences with the iPath telepathology server of Basel University. One hundred sixty one cases in a period of 32 months were consulted. These cases received for second evaluation but the definite diagnosis could not be made in this centre. The number of images per case ranged from 3 to 32 (mean: 8). Except one case all cases were evaluated by consultants. Definite final diagnosis was achieved in 88/160 (54.7%). Recommendations for further evaluation were offered in 42/160 cases (26%). Major discrepancies were encountered in 30/160 cases (19%). Thirty-nine of the cases (24.3%) were reported within 1 day. The rate of achieving final diagnosis was higher in histological group rather than cytological ones. Increase in number of H&E images had no significant effect on achieving a definite final diagnosis. The rate of achieving final diagnosis in this study is much lower than other similar studies, which could be due to inappropriate sampling images, a potential cause of misdiagnosis in static telepathology. The other possible reason is that all of the cases in this study were problematic cases that a definite diagnosis could not be made for them even in primary consultation. The mean time for achieving a final diagnosis was also more than other studies, which could be for the reasons mentioned above.

[Digitalized imaging pathology: application to quality control in cancer diagnosis]

OBJECTIVES

To test a double histology reading system based on digitalized imaging for cancer diagnosis.

MATERIAL AND METHODS

Pathology images of cancer diagnosis material were produced in real time by a digital imaging system integrated into the laboratory data processing system. Over a 30-day period, second readings were performed using the digitalized images. Cases with second readings were classified according to the aspect on the digitalized images as malignant tumor with histological type, malignant tumor with no other precision, and doubtful malignancy.

RESULTS

During the study period, 204 cases of cancer were diagnosed, including 178 with digitalized imaging (87%). Among the digitalized cases, 119 (67%) were classified as malignant tumor with histological type, 53 (30%) as malignant tumor with no other precision, and 6 (3%) as doubtful malignancy. The histology material of these latter cases were reviewed and corresponded to malignant tumors. Approximately 2 hours per week were devoted to the second readings.

CONCLUSION

A integrated digitalized imaging system can participate in quality control of cancer diagnosis by allowing rapid efficacious second readings.

An array microscope for ultrarapid virtual slide processing and telepathology. Design, fabrication, and validation study

This paper describes the design and fabrication of a novel array microscope for the first ultrarapid virtual slide processor (DMetrix DX-40 digital slide scanner). The array microscope optics consists of a stack of three 80-element 10 x 8-lenslet arrays, constituting a "lenslet array ensemble." The lenslet array ensemble is positioned over a glass slide. Uniquely shaped lenses in each of the lenslet arrays, arranged perpendicular to the glass slide constitute a single "miniaturized microscope." A high-pixel-density image sensor is attached to the top of the lenslet array ensemble. In operation, the lenslet array ensemble is transported by a motorized mechanism relative to the long axis of a glass slide. Each of the 80 miniaturized microscopes has a lateral field of view of 250 microns. The microscopes of each row of the array are offset from the microscopes in other rows. Scanning a glass slide with the array microscope produces seamless two-dimensional image data of the entire slide, that is, a virtual slide. The optical system has a numerical aperture of N.A.= 0.65, scans slides at a rate of 3 mm per second, and accrues up to 3,000 images per second from each of the 80 miniaturized microscopes. In the ultrarapid virtual slide processing cycle, the time for image acquisition takes 58 seconds for a 2.25 cm2 tissue section. An automatic slide loader enables the scanner to process up to 40 slides per hour without operator intervention. Slide scanning and image processing are done concurrently so that post-scan processing is eliminated. A virtual slide can be viewed over the Internet immediately after the scanning is complete. A validation study compared the diagnostic accuracy of pathologist case readers using array microscopy (with images viewed as virtual slides) and conventional light microscopy. Four senior pathologists diagnosed 30 breast surgical pathology cases each using both imaging modes, but on separate occasions. Of 120 case reads by array microscopy, there were 3 incorrect diagnoses, all of which were made on difficult cases with equivocal diagnoses by light microscopy. There was a strong correlation between array microscopy vs. "truth" diagnoses based on surgical pathology reports. The kappa statistic for the array microscopy vs. truth was 0.96, which is highly significant (z=10.33, p <0.001). There was no statistically significant difference between rates of agreement with truth between array microscopy and light microscopy (z=0.134, p >0.05). Array microscopy and light microscopy did not differ significantly with respect to the number/percent of correct decisions rendered (t=0.552, p=0.6376) or equivocal decisions rendered (t=2.449, p=0.0917). Pathologists rated 95.8% of array microscopy virtual slide images as good or excellent. None were rated as poor. The mean viewing time for a DMetrix virtual slide was 1.16 minutes. The DMetrix virtual slide processor has been found to reduce the virtual slide processing cycle more than 10 fold, as compared with other virtual slide systems reported to date. The virtual slide images are of high quality and suitable for diagnostic pathology, second opinions, expert opinions, clinical trials, education, and research.

Telecytology in Hokkaido Island, Japan: results of primary telecytodiagnosis of routine cases

In 1997, an Internet-based static image telepathology system was built at Sapporo National Hospital, Japan. We can exchange high-resolution microscopical images through a file transfer protocol server and discuss cytological findings and diagnosis on an electronic mailing list. We applied the system to primary telecytodiagnosis. From May 1997 to April 1999 we have made diagnoses of 614 daily cases only by looking at the video monitor images transmitted from the cytotechnologist of Wakkanai Municipal Hospital 300 km distant from Sapporo. The concordance between telecytodiagnosis and glass slide diagnosis was 88.6%. Kappa statistics for cervical smears was 0.919 and that for specimens other than uterine cervix was 0.810. The accuracy of telecytodiagnosis was 91.4%, and was not substantially different from that of the conventional mail-based cytology in a previous year. We had five cases with a severely inappropriate diagnosis in telecytology, all of which however were quickly corrected by follow-up histological or cytological specimens. With the use of an electronic mailing list the participants had quick and sufficient discussions. We conclude that telecytology is very useful for primary cytodiagnosis in regional medicine and that it may raise the accuracy of cytodiagnosis in future, if we make consistent efforts to reflect the benefits of telecytology in daily practices. This is the first report of clinical results of telecytology from Japan.

An automated tissue preclassification approach for telepathology: implementation and performance analysis

Telepathology is generally defined as the use of telecommunications technologies in the practice of anatomic or surgical pathology. In the usual telepathology scenario, a remotely located pathologist views images of tissues samples in order to render a diagnosis of the biopsy. Some telepathology systems involve interactive remote control of a microscope-based imaging system which delivers diagnostic quality imagery to the remote pathologist. The usefulness of such interactive systems depends on minimizing the end-to-end delays involved in controlling the robotic microscope, manipulating the tissue sample, and acquiring and transmitting the high-resolution image. An approach to minimizing end-to-end delay involves adding "intelligence" to the image acquisition system so that it can gather, classify, rank, and transmit diagnostically useful images in a semiautonomous fashion. In this research, we develop image analysis and ranking techniques which can improve the end-to-end performance of a robotic telepathology imaging system. Our semiautonomous image collection system uses morphological techniques to extract seed points for suspicious regions, a novel region growing algorithm to segment the regions of interest, and heuristically motivated expert system ranking techniques to select diagnostically relevant "next-step" image acquisitions. Diagnostic relevance of our segmentation and ranking algorithms is established via subjective and objective testing of the system. In subjective testing, pathologists Agree or Strongly Agree that all segmented regions are diagnostically relevant with probability greater than 0.75. In objective testing, 84% of "next-step" images acquired by our algorithms coincide with the areas most likely to be chosen by a pathologist.

The virtual microscope

We present the design and implementation of the Virtual Microscope, a software system employing a client/server architecture to provide a realistic emulation of a high power light microscope. The system provides a form of completely digital telepathology, allowing simultaneous access to archived digital slide images by multiple clients. The main problem the system targets is storing and processing the extremely large quantities of data required to represent a collection of slides. The Virtual Microscope client software runs on the end user's PC or workstation, while database software for storing, retrieving and processing the microscope image data runs on a parallel computer or on a set of workstations at one or more potentially remote sites. We have designed and implemented two versions of the data server software. One implementation is a customization of a database system framework that is optimized for a tightly coupled parallel machine with attached local disks. The second implementation is component-based, and has been designed to accommodate access to and processing of data in a distributed, heterogeneous environment. We also have developed caching client software, implemented in Java, to achieve good response time and portability across different computer platforms. The performance results presented show that the Virtual Microscope systems scales well, so that many clients can be adequately serviced by an appropriately configured data server.

Image quality issues in a static image-based telepathology consultation practice

Field selection and image quality have often been identified as impediments in the successful employment of static-image telepathology. One thousand seven hundred fifty-three electronic consultations using static images were performed at the Department of Telemedicine, Armed Forces Institute of Pathology (AFIP) between November 1994 and September 2001, with 98.3% receiving a telepathology diagnosis. In 47.9% of cases, imagery was considered good by AFIP consultants, 38.5% were considered adequate, and 14.6% of cases were considered to have poor-quality imagery. Deficiencies in image quality were recorded for each case. Cases with imagery rated as good averaged significantly fewer deficiencies per case (0.45, range: 0 to 3) than cases with imagery rated adequate (0.95, range: 0 to 6) or poor (2.4, range: 0 to 7). Deficiencies in focus were most commonly identified in this series of cases (28.1%), followed by improper white balancing of the capture device (14.1%) and inadequate resolution (10%). Cases in which images were of inadequate resolution showed an increased likelihood for discordance between the telepathology diagnosis and the diagnosis rendered on follow-up material ("truth diagnosis"). Inadequate field selection, although only cited in 6.7% of cases overall, was seen with a significantly higher frequency in cases in which there was discordance between the telepathology and truth diagnosis. A review of common image deficiencies in static-image telepathology and possible causes is presented.

Digital slide and virtual microscopy based routine and telepathology evaluation of routine gastrointestinal biopsy specimens

AIMS

To evaluate a recently developed digital slide and virtual microscope system, and to compare this method with optical microscopy on routine gastrointestinal biopsy specimens in both local and remote access modes.

METHODS

A fully computer controlled commercial microscope was used. The scanning program included object detection, autofocus, and image compression algorithms. The overall hard disk space for a gastric biopsy was between 30 and 50 MB and the scanning time was between 20 and 40 minutes. Haematoxylin and eosin stained routine gastric (61) and colon (42) biopsy specimens were selected, scanned, and evaluated by two specialists on an optical (OM) and virtual microscope (VM).

RESULTS

The overall concordance of VM and OM with the consensus diagnosis was 95.1% and 97%, respectively. Clinically important concordance was 96.1% and 98% for VM and OM, respectively. The two methods showed concordance in 92% of cases and clinically important concordance in 94.1% of cases. The reasons for discordance were image quality (one case), interpretation difference (three cases), and insufficient clinical information (three cases). Remote evaluation of the digital slides through the Internet has the advantages of the previously used static and dynamic telepathology methods.

CONCLUSIONS

Diagnostic concordance was found between OM and VM. The digital slide and the virtual microscope can be alternative techniques in the computerisation of the histology laboratory and in teleconsultation services after further evaluation of time and storage constraints.

Telepathology: current status and future prospects in diagnostic histopathology

Telepathology is the process of diagnostic histopathology performed on digital images viewed on a display screen rather than by conventional glass slide light microscopy. The technology of telepathology has radically improved over the past 5 years so that it is no longer the limiting factor in the diagnostic process. This review looks at the resources needed for dynamic and static telepathology, including image quality, computers and software interfaces, means of transmission and human resources. It critically analyses 32 published trials of telepathology, including some large prospective studies, in all areas of diagnostic histopathology including intraoperative frozen sections, routine and referral cases. New developments, including internet solutions and virtual microscopy, are described and there is analysis of the economics of telepathology within health care systems. The review concludes that all the necessary technology for telepathology is available, there is strong published evidence for a diagnostic accuracy comparable with glass slide diagnosis, in many contexts there is a clear-cut economic argument in favour of telepathology, and that the technique should now be integrated into mainstream diagnostic histopathology.

Transcontinental communication and quantitative digital histopathology via the Internet; with special reference to prostate neoplasia

OBJECTIVE

To describe practical experiences in the sharing of very large digital data bases of histopathological imagery via the Internet, by investigators working in Europe, North America, and South America.

MATERIALS

Experiences derived from medium power (sampling density 2.4 pixels/microm) and high power (6 pixels/microm) imagery of prostatic tissues, skin shave biopsies, breast lesions, endometrial sections, and colonic lesions. Most of the data included in this paper were from prostate. In particular, 1168 histological images of normal prostate, high grade prostatic intraepithelial neoplasia (PIN), and prostate cancer (PCa) were recorded, archived in an image format developed at the Optical Sciences Center (OSC), University of Arizona, and transmitted to Ancona, Italy, as JPEG (joint photographic experts group) files. Images were downloaded for review using the Internet application FTP (file transfer protocol). The images were then sent from Ancona to other laboratories for additional histopathological review and quantitative analyses. They were viewed using Adobe Photoshop, Paint Shop Pro, and Imaging for Windows. For karyometric analysis full resolution imagery was used, whereas histometric analyses were carried out on JPEG imagery also.

RESULTS

The three applications of the telecommunication system were remote histopathological assessment, remote data acquisition, and selection of material. Typical data volumes for each project ranged from 120 megabytes to one gigabyte, and transmission times were usually less than one hour. There were only negligible transmission errors, and no problem in efficient communication, although real time communication was an exception, because of the time zone differences. As far as the remote histopathological assessment of the prostate was concerned, agreement between the pathologist's electronic diagnosis and the diagnostic label applied to the images by the recording scientist was present in 96.6% of instances. When these images were forwarded to two pathologists, the level of concordance with the reviewing pathologist who originally downloaded the files from Tucson was as high as 97.2% and 98.0%. Initial results of studies made by researchers belonging to our group but located in others laboratories showed the feasibility of making quantitative analysis on the same images.

CONCLUSIONS

These experiences show that diagnostic teleconsultation and quantitative image analyses via the Internet are not only feasible, but practical, and allow a close collaboration between researchers widely separated by geographical distance and analytical resources.

Telepathology for the biopsy specimens from human allografted kidney: effectiveness and pitfalls

This study was conducted to examine the validity and accuracy of telepathology for biopsy specimens from allografted kidney. The still video images of paraffin sections were transmitted via a two-way telephone by use of a digitized telephone network, ISDN. The quality of the transmitted images was sufficient for the diagnosis, especially at higher magnification. A total of 37 needle biopsy specimens from the 31 allografted kidneys were presented for consultation and diagnosed by an expert pathologist at Tottori University, until July 2000. The average number of transmitted images was 7.1 (range 3-12). Of the 37 specimens, diagnoses by telepathology agreed well with those made through direct microscopy in the 30 specimens. Insufficient or improper diagnosis was made in four specimens, in which proper and pathognomonic still images were not transmitted. Three cases were not diagnosed by telepathology because of the difficulty in making differential diagnosis. From these results, we concluded that telepathology is useful for transplantation pathology, in spite of limitations in some cases.

Use of dynamic telepathology in Mohs surgery: a feasibility study

BACKGROUND

Telepathology is an emerging technology for remote pathology consultation and diagnosis.

OBJECTIVE

To assess the diagnostic accuracy and utility of a dynamic telepathology system in the setting of Mohs surgery.

METHODS

Using a dynamic telepathology system, a single dermatopathologist at a remote site assessed the following cases: (1) 50 fixed-tissue slides of basal and squamous cell carcinomas for pathologic diagnosis; (2) 40 frozen-section slides from Mohs surgery for the presence or absence of tumor; (3) 20 frozen-section slides from Mohs surgery for intraoperative consultation with the Mohs surgeon. All 110 slides were then randomly reviewed by the same dermatopathologist by conventional light microscopy. Telepathology and conventional light microscopy diagnoses were then compared.

RESULTS

There was complete agreement between telepathology and conventional light microscopy diagnoses.

CONCLUSION

Dynamic telepathology is a convenient, useful, and accurate system for remote diagnosis and consultation in the setting of Mohs surgery.