Telepathology diagnosis of prostrate needle biopsies

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.

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.

Reproducibility of telecytology diagnosis of cervical smears in a quality assurance program: the Georgian experience

OBJECTIVE

The study evaluated the reproducibility of telecytology diagnosis of cervical smears on a randomly selected 50 cases under the conditions of Georgia.

MATERIALS AND METHODS

Fifty cervical smears (benign, 14; atypical squamous cells of undetermined significance [ASCUS], 14; low-grade squamous intraepithelial lesion [LSIL], 10; high-grade squamous intraepithelial lesion [HSIL], 12) were selected. The digital images were captured at a maximum resolution of 2048 × 1536 pixels and transmitted by electronic mail. Diagnosis of glass slides and digital images was done independently in a double-blind manner by three cytologists, versus the diagnosis of digital images followed by diagnosis of glass slides 3 months later. The procedure was repeated after 3 months.

RESULTS

Diagnoses were recorded as benign, ASCUS, LSIL, and HSIL. Diagnostic accuracy and interobserver reproducibility were analyzed using an interclass correlation coefficient, which revealed good interobserver agreement for the first (0.82) and second (0.68) glass slide diagnoses and the first (0.80) and second (0.66) digital image diagnoses. The kappa values for interobserver variation between first and second glass slide diagnoses and first and second digital image diagnoses showed good to excellent agreement.

CONCLUSIONS

Digital images are suitable substitutes for glass slides; telecytology can be used as an alternative method for the cytologic diagnosis of cervical smears, particularly in quality assurance programs.

Digital pathology: current status and future perspectives

During the last decade pathology has benefited from the rapid progress of image digitizing technology. The improvement in this technology had led to the creation of slide scanners which are able to produce whole slide images (WSI) which can be explored by image viewers in a way comparable to the conventional microscope. The file size of the WSI ranges from a few megabytes to several gigabytes, leading to challenges in the area of image storage and management when they will be used routinely in daily clinical practice. Digital slides are used in pathology for education, diagnostic purposes (clinicopathological meetings, consultations, revisions, slide panels and, increasingly, for upfront clinical diagnostics) and archiving. As an alternative to conventional slides, WSI are generally well accepted, especially in education, where they are available to a large number of students with the full possibilities of annotations without the problem of variation between serial sections. Image processing techniques can also be applied to WSI, providing pathologists with tools assisting in the diagnosis-making process. This paper will highlight the current status of digital pathology applications and its impact on the field of pathology.

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

Low-cost telepathology system for intraoperative frozen-section consultation: our experience and review of the literature

We have established a low-cost noncommercial system of dynamic real-time telepathology for light microscopic diagnosis that was used to aid intradepartmental consultation for frozen-section diagnosis. Fifty cases were performed. For each case, multiple diagnoses were made and compared, namely, those made by the pathologist on duty (D1), by a subspecialist or senior using telepathology (D2), by the same pathologist using a light microscope (D3), and the final diagnosis (D4). A comparison of D1 and D2 revealed that 37 cases (74%) were diagnosed more precisely by D2. In 9 (18%) of 50 cases, there was a positive major impact on the operation as a result of teleconsultation. The results of D2 and D3 showed good agreement (kappa = 0.97). The average time span required for telepathology is short compared with routine intradepartmental consultation. Our experience showed that telepathology is a good tool for frozen-section consultation and imposes little additional cost.

Grid technology in tissue-based diagnosis: fundamentals and potential developments

Tissue-based diagnosis still remains the most reliable and specific diagnostic medical procedure. It is involved in all technological developments in medicine and biology and incorporates tools of quite different applications. These range from molecular genetics to image acquisition and recognition algorithms (for image analysis), or from tissue culture to electronic communication services. Grid technology seems to possess all features to efficiently target specific constellations of an individual patient in order to obtain a detailed and accurate diagnosis in providing all relevant information and references. Grid technology can be briefly explained by so-called nodes that are linked together and share certain communication rules in using open standards. The number of nodes can vary as well as their functionality, depending on the needs of a specific user at a given point in time. In the beginning of grid technology, the nodes were used as supercomputers in combining and enhancing the computation power. At present, at least five different Grid functions can be distinguished, that comprise 1) computation services, 2) data services, 3) application services, 4) information services, and 5) knowledge services. The general structures and functions of a Grid are described, and their potential implementation into virtual tissue-based diagnosis is analyzed. As a result Grid technology offers a new dimension to access distributed information and knowledge and to improving the quality in tissue-based diagnosis and therefore improving the medical quality.

Development and preliminary evaluation of the VPS ReplaySuite: a virtual double-headed microscope for pathology

BACKGROUND

Advances in computing and telecommunications have resulted in the availability of a range of online tools for use in pathology training and quality assurance. The majority focus on either enabling pathologists to examine and diagnose cases, or providing image archives that serve as reference material. Limited emphasis has been placed on analysing the diagnostic process used by pathologists to reach a diagnosis and using this as a resource for improving diagnostic performance.

METHODS

The ReplaySuite is an online pathology software tool that presents archived virtual slide examinations to pathologists in an accessible video-like format, similar to observing examinations with a double-headed microscope. Delivered through a customized web browser, it utilises PHP (Hypertext PreProcessor) to interact with a remote database and retrieve data describing virtual slide examinations, performed using the Virtual Pathology Slide (VPS). To demonstrate the technology and conduct a preliminary evaluation of pathologists opinions on its potential application in pathology training and quality assurance, 70 pathologists were invited to use the application to review their own and other pathologists examinations of 10 needle-core breast biopsies and complete an electronic survey. 9 pathologists participated, and all subsequently completed an exit survey.

RESULTS

Of those who replayed an examination by another pathologist, 83.3% (5/6) agreed that replays provided an insight into the examining pathologists diagnosis and 33.3% (2/6) reconsidered their own diagnosis for at least one case. Of those who reconsidered their original diagnosis, all re-classified either concordant with group consensus or original glass slide diagnosis. 77.7% (7/9) of all participants, and all 3 participants who replayed more than 10 examinations stated the ReplaySuite to be of some or great benefit in pathology training and quality assurance.

CONCLUSION

Participants conclude the ReplaySuite to be of some or of great potential benefit to pathology training and quality assurance and consider the ReplaySuite to be beneficial in evaluating the diagnostic trace of an examination. The ReplaySuite removes temporal and spatial issues that surround the use of double-headed microscopes by allowing examinations to be reviewed at different times and in different locations to the original examination. While the evaluation set was limited and potentially subject to bias, the response of participants was favourable. Further work is planned to determine whether use of the ReplaySuite can result in improved diagnostic ability.

Nonspecific (idiopathic) granulomatous prostatitis associated with low-grade prostatic adenocarcinoma

Nonspecific granulomatous prostatitis (NSGP) is uncommon and may simulate carcinoma both clinically and microscopically. Concurrent NSGP and prostatic adenocarcinoma is rare. To our knowledge this association has been documented once and it was only rarely mentioned in two large series of NSGP. We describe a 67-year-old man who presented with a history of prostatism of 1 month's duration. Suprapubic prostatectomy revealed NSGP associated with nodular hyperplasia and low-grade prostatic adenocarcinoma. The pathologist should be aware of the rare association of NSGP and prostatic adenocarcinoma. Wide sampling of the prostatectomy specimens with NSGP is mandatory to exclude an occult prostatic adenocarcinoma.

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.

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.

Diagnostic accuracy of second-opinion diagnoses based on still images

Second opinion of histological specimens is an important part of the daily routine in anatomic pathology practices. Today, extramural second opinion can be easily obtained by sending still images via an electronic network. The aim of this study was to examine the diagnostic accuracy of second opinion diagnosis based on still images selected from glass slides of 90 archived cases originally referred for extramural second opinion. Two pathologists together diagnosed first the still images (phase 1) and then the glass slides (phase 2). Phase 1 and phase 2 diagnoses were compared with the original second opinion diagnoses (OSODs). The pathologists achieved the same diagnostic results in phase 1 and in phase 2 measured against the OSOD, 67.8% (n = 61) and 68.9% (n = 62) complete agreement, respectively. In 29 cases in phase 1, the diagnoses were discordant with the OSOD. Three cases had incorrect benign diagnoses and 8 cases had incorrect malignant diagnoses. There were 8 false-negative diagnoses regarding malignancy, 6 false-positive diagnoses regarding malignancy, and 4 other discordant diagnoses. Eleven of the 29 discordant diagnoses could have had clinical implications. In interpreting these results, it is important to acknowledge the observer variability in diagnostic histopathology in general. In conclusion, the results support the concept of using still images to obtain second opinion diagnosis.

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.

Outcomes and Methods in Telemedicine Evaluation

One hundred and four articles, published from 1966 to 2000, were reviewed to investigate telemedicine evaluation studies in terms of methods and outcomes. A total of 112 evaluations were reported in these 104 articles. Two types of evaluations were evaluated: clinical and nonclinical. Within the clinical evaluations, three were on clinical effectiveness, 26 on patient satisfaction, 49 on diagnostic accuracy, and nine on cost. In the non-clinical evaluations, 15 articles discussed technical issues relating to digital images, such as bandwidth, resolution, and color, and 10 articles assessed management issues concerning efficiency of care, such as avoiding unnecessary patient transfer, or saving time. Of the 112 evaluations, 72 were descriptive in nature. The main methods used in the remaining 40 articles used quantitative methods. Nineteen articles employed statistical techniques, such as receiver operating characteristics curve (three evaluations) and kappa values (seven evaluations). Only one article utilized a qualitative approach to describe a telemedicine system. Currently, there are a number of good reports on diagnostic accuracy, satisfaction, and technological evaluation. However, clinical effectiveness and cost-effectiveness are important parameters, and they have received limited attention. Since telemedicine evaluations tend to explore various outcomes, it may be appropriate to evaluate from a multidisciplinary perspective, and to utilize various methodologies.

Development and evaluation of the virtual pathology slide: a new tool in telepathology

BACKGROUND

The Virtual Pathology Slide is an interactive microscope emulator that presents, via the Internet or CD-ROM, a complete 15.53 mm x 11.61 mm digitalized tissue section. The Virtual Pathology Slide mimics the use of a microscope in both the stepwise increase in magnification (from 16x up to 2000x) and in lateral motion in the X and Y Cartesian directions. This permits a pathologist to navigate to any area on a slide, at any magnification, similar to a conventional microscope.

OBJECTIVE

The aim of this study was to assess the diagnostic accuracy and acceptability of the Virtual Pathology Slide.

METHODS

Ten breast needle core biopsies were randomly selected and presented to 17 pathologists or trainee pathologists with at least 2 years experience in pathology practice. Participants were required to examine each case online and provide a diagnostic classification using online feedback forms. The recorded data permitted examination of interobserver variability and user satisfaction.

RESULTS

Agreement between original glass-slide diagnosis and consensus diagnosis using the Virtual Pathology Slide was reached in 9 out of 10 slides. Percentage concordance for slides lay in the range of 35.3% to 100% with an average percentage concordance between slides of 66.5%. The average Kappa statistics for interobserver agreement was 0.75 while average percentage concordance amongst participants was 66.5%. Participants looked at an average of 22 fields of view while examining each slide. Confidence: 81.25% of the participants indicated confidence using the Virtual Pathology Slide to make a diagnostic decision, with 56.25% describing themselves as "reasonably confident," 18.75% as "confident," and 6.25% as "very confident." Ease of use: 68.75% reported the system as "easy" or "very easy" to use. Satisfaction: 87.5% of participants expressed satisfaction with image quality, with 43.75% describing the image quality as "adequate," 25% describing it as "good," and 18.75% describing the image quality as "excellent." Pathologists with a working bandwidth greater than 20 kilobits per second found the download speed of the Virtual Pathology Slide "adequate" or better.

CONCLUSIONS

Results from this study show that the Virtual Pathology Slide can be used to make a correct diagnostic decision, and that the system is a realistic alternative to dynamic telepathology.

Store-and-forward diagnostic telepathology of small biopsies by e-mail attachment: a feasibility pilot study with a view for future application in Thailand diagnostic pathology services

Diagnostic telepathology by electronic mail (e-mail) attachment is relatively simple and incurs minimal cost. We assessed its accuracy and practical aspects in routine diagnostic pathology. Using 100 small biopsy specimens, a total of 1,488 images were digitized by one pathologist and sent as e-mail attachments from Nara Medical University, Japan, to a pathologist at Rajavithi Hospital, Thailand. His diagnoses were compared with his conventional light microscopy interpretation at a later date. The average total turnaround time spent on each case was 215 minutes, far less than the several days required by conventional post. There were two clinically significant errors. One was a diagnostically difficult case of colonic dysplasia, which was called carcinoma with telepathology. The other was a signet ring cell carcinoma of the stomach which was undetected with telepathology. Microscopy objective magnification and digital image quality may have played a role in impairing interpretation in both cases. Store-and-forward telepathology provides acceptable efficacy, a comparatively faster turnaround time than post and could be applied in routine work within Thai pathology services.

Real-time collaborative environment for radiation treatment planning virtual simulation

A virtual simulation (VS) system is a software system that enables the delineation of anatomical structures, and the placement of irradiation fields for the purpose of radiation treatment planning, making use of patient's tomographic data, instead of the real patient. Since patient's tomographic data can be communicated between distinct radiotherapy departments, collaborative work on VS, connecting remote health care professionals, becomes feasible. In this paper, an environment enabling real-time collaboration on VS is presented. The environment architecture is based on both offline and online communication of data under a secure framework and can be directly integrated into the infrastructure of a radiotherapy department. The online collaboration relies on the simultaneous execution of all actions at both collaborating sites, and prerequisites the offline communication of the data set on which the collaboration will be performed. Analytical description of the custom-made layered service, which supports the offline communication is given, along with a detailed presentation of the secure management of messages, which enables the real-time collaboration. The technical evaluation of the environment highlights the effectiveness of the proposed methodology, since real-time secure collaboration on VS is achieved.

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.

Practical telepathology using a digital camera and the internet

Digital camera technology has developed rapidly and a large choice of reasonably priced, user-oriented models are now available. These can be used for both macroscopic and microscopic photography with good resolution. Internet transmission of digital images also makes it possible to consult pathologists anywhere in the world. This study tests a simple, fast, and inexpensive method for practical transmission of images for diagnosis using a digital camera and the Internet. Using a commercial digital camera mounted with a phototube adapter to a light microscope (6 images per case on average), 2210 digital images (310 Mb) from 347 cases of gastrointestinal, lung, and uterus specimens were captured. Each image, stored in medium compression JPEG (Joint Photographers Experts Group) format with 1024 x 768 pixel resolution, required approximately 5 seconds to capture after the case had been reviewed and appropriate fields for imaging selected (30 seconds per case on average). The images were transmitted from Samsung Medical Center, Seoul, to Korea University Hospital, Seoul, and John Hunter Hospital, Newcastle, Australia. Transmission was 100% successful with a total upload time of 3 hours for 310 MB of data (31 seconds per case on average). The images were downloaded in 2 hours and viewed on a 17-inch color monitor with a maximal resolution of 1280 x 1024 pixels. Telepathology diagnoses were made with 95% and 97% concurrence by two pathologists at Korea University Hospital and John Hunter Hospital, respectively. We suggest that the current level of commercial technology yields fast, convenient and economical tools for practical telepathology diagnosis.

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.

Theory and applications of telemedicine

In this study, telemedicine and the use of advanced telemedicine technologies are explained. Telemedicine is the use of modern telecommunications and information technologies for the provision of clinical care to individuals at a distance, and transmission of information to provide that care. Telemedicine can be used for decision making, remote sensing, and collaborative arrangements for the real-time management of patients at a distance. The use of telecommunications and information technologies in providing health services is determined. Telemedicine is described as combination of topics from the fields of telecommunication, medicine, and informatics. The medical systems infrastructure consisting of the equipment and processes used to acquire and present clinical information and to store and retrieve data are explained in details. The challenges existing in telemedicine development in different countries are given. Technological, political, and professional barriers in applications of telemedicine are defined. An investigation of telemedicine applications in various fields is presented, and enormous impact of telemedicine systems on the future of medicine is determined.

Telepathology for routine light microscopic and frozen section diagnosis

Telepathology (TP) uses telecommunication linkages to electronically capture, store, retrieve, and transmit images to distant sites. We assessed the feasibility of a dynamic real-time TP system for light microscopic (LM) diagnosis of anatomic pathology specimens, including frozen sections. Six pathologists, in 2 separate periods, read a set of 160 retrospectively retrieved slides (80 of which were frozen sections) by TP and LM. Reading times were recorded. Diagnoses were compared with the reference diagnosis (established by a group of 5 independent pathologists) and graded on a scale of 0 to 2 (2, correct; 1, incorrect but no clinical impact; 0, incorrect with clinical impact). Overall, LM was more accurate than TP compared with the reference diagnosis (score, 1.68 vs 1.54). There was no difference in accuracy between frozen section and paraffin-embedded tissue. Intraobserver agreement ranged from 82.5% to 88.2%. The average reading time was 6.0 minutes for TP and 1.4 minutes for LM. During the study, reading time decreased for TP but not for LM. These results show that despite marginally lower accuracy and longer reading times, TP isfeasible for routine light microscopic diagnosis, including frozen sections.

Internet teleconferencing method for telepathology consultations from lung and heart transplant patients

Current Internet-based teleconferencing techniques allow a referring pathologist to transmit real-time images from a microscope to a consultant, while maintaining a verbal conversation using Internet telephony. In our study, 50 randomly selected transbronchial biopsies from lung allograft recipients and 58 randomly selected endomyocardial biopsies from heart transplant patients were diagnosed by consultant pathologists using Internet-based teleconferencing methods. The referring pathologists acquired the real-time video images from the biopsies using a light microscope equipped with a phototube adapter and a video camera. The consultant pathologists viewed the processed images on a video monitor at 800 x 600 resolution, using a standard microcomputer equipped with Netmeeting software, and directed the referring pathologist to move the slide under the microscopy and/or change image magnification. The validity of telepathology diagnoses was assessed with kappa coefficients. Consultations were completed in 5 to 15 minutes per case. Sound transmission was unreliable, and in approximately 25% of consultations the referring pathologist needed to "call back" to reestablish verbal communication. In all but 2 transbronchial biopsies there was agreement between the original diagnosis and the diagnosis by telepathology (kappa = 0.92). In 48 of 58 endomyocardial biopsies there was concordance between the 2 diagnoses (kappa = 0.692). Only 3 out of 10 of these discrepancies were clinically significant (kappa = 0.897). Internet-based teleconferencing techniques provide effective and relatively inexpensive tools for real time telepathology consultations. The technology is probably best suited for the study of small specimens from patients that require rapid diagnosis by a consultant.

Interobserver variability in the diagnosis of ulcerative colitis-associated dysplasia by telepathology

Telepathology (TP) is the practice of remote diagnostic consultation of electronically transmitted, static, digitalized images. The diagnostic efficacy of TP-based consultation services has not been widely tested. Dysplasia that arises in association with chronic ulcerative colitis (CUC) is, at present, the most important marker of an increased risk of malignancy in patients with this disease. Unfortunately, dysplasia is difficult to diagnose histologically and, as a result, suffers from a significant degree of intra- and interobserver variability. Furthermore, it is often necessary to obtain expert consultation of potential CUC-associated dysplasia cases before treatment. Therefore, the aim of this study was to evaluate the utility and interobserver variability of diagnosing dysplasia in CUC with the use of TP. Static, electronically transmitted, digitalized images of 38 CUC cases with areas considered negative, indefinite, or positive for dysplasia (low or high grade) were evaluated independently by four gastrointestinal pathologists. All cases were then graded by each of the pathologists by light-microscopic examination of the hematoxylin and eosin-stained glass slides. The degree of interobserver variability was determined by kappa statistics. Overall, there was a fair degree of agreement (kappa = 0.4) among the four reviewing pathologists after analysis of the digitalized images. The poorest level of agreement was in the indefinite and low-grade dysplasia categories. Grouping together several diagnostic categories (for instance, indefinite and low-grade dysplasia, or low-grade dysplasia and high-grade dysplasia) had no effect on the overall level of agreement. The degree of variability in interpretation of glass slides was slightly better (kappa = 0.43) but still remained fair. After reviewing all cases by glass slide analysis, the diagnosis was changed in 38% of the slides; in the majority of these, the grade of dysplasia was increased. Use of TP for consultation in CUC-associated dysplasia has a moderate level of interobserver agreement. Because of a variety of technical reasons, diagnoses rendered by evaluation of digitalized images tended to be of a lower grade than that observed after a review of the glass slides.

Offline telepathology diagnosis of colorectal polyps: a study of interobserver agreement and comparison with glass slide diagnoses

BACKGROUND/AIMS

Technological advances have produced telepathology systems with high quality colour images and reasonable transmission times. Most applications of telepathology have centred on the remote diagnosis of frozen sections or remote real time expert opinions. This study investigates the reproducibility and accuracy of offline telepathology as a primary diagnostic medium for routine histopathology specimens.

METHODS

One hundred colorectal polyps (50 hyperplastic, 50 adenomatous) were presented in a randomised order to five histopathologists as offline images on a telepathology workstation. Six images of each case were used: the slide label, a low power scan of all material on the slide, and four higher magnification views. The times taken to prepare the images, and to make the diagnoses, were recorded. Interobserver agreement was measured with kappa statistics and compared with the glass slide diagnoses.

RESULTS

The kappa statistics for the interobserver agreement on the telepathology images lay in the range of 0.90-1.00, which is interpreted as excellent agreement, and were significantly higher than those for the glass slide diagnoses (range, 0.84-0.98; p = 0.001). The median time taken to capture the images for a case was 210 seconds. The median time taken to make a diagnosis from the telepathology images was five seconds, which was significantly shorter than for the glass slide diagnoses (median, 13 seconds; p < 0.0005).

CONCLUSIONS

Offline telepathology has the potential to be a primary diagnostic medium for routine histopathology with a high degree of reproducibility and short diagnosis times. Further studies are required to validate offline telepathology for different types of specimens and different operators of the image capture system.

Diagnosing minimal adenocarcinoma on prostate needle biopsy by real-time dynamic telepathology through the internet: evaluation of an economic technology for remote consultation

Computer-aided telepathology was introduced about 10 years ago, but has not yet met with worldwide acceptance. Recently, the internet has been used for image transmission in telepathology. We set up an easily assembled system comprising a common microscope, a charge-coupled device (CCD) camera, a personal computer, and a commercial internet surveillance program with internet accessibility. The consultant then views the real-time images using a common web browser at the remote site. The purpose of the study was to assess the ability of the system to transmit images of sufficient quality to achieve high concordance between the diagnoses made at the home base and at the remote site. We chose cases of minimal adenocarcinoma on prostate needle biopsy, because these lesions are liable to be overlooked and, even if discovered, are subject to differences in interpretation due to their limited size and subtle histologic changes. One hundred prostate needle biopsy specimens, including 45 minimal adenocarcinoma, 11 atypical small acinar proliferation, and 44 benign lesions, were tested. Two pathologists, unaware of the final diagnoses, were recruited to provide intra- and interinstitutional consultation. The overall concordance rates between telepathology diagnoses and final diagnoses were 97% and 94% for the two pathologists, respectively. Our results demonstrate that this method is effective for teleconsultation. Similar systems using the internet can be easily set up by ordinary pathology laboratories to facilitate remote consultation.

Application of virtual microscopy in clinical cytopathology

Virtual microscopy (VM) refers to the use of an automated microscope and digital imaging technology to scan, store, and view glass slides. VM systems allow the user to view a scanned image of the entire slide at multiple magnifications on a computer screen. We tested VM to evaluate its possible utility in diagnostic cytopathology. Ten cervical-vaginal monolayered preparations (AutoCyte preparation) were scanned using a BLISS (Bacus Laboratories Inc. Slide Scanner) system. Approximately 20-30% of the cellular area of each slide was imaged. The cases were randomly chosen to include examples ranging from benign cellular changes (BCC) to high-grade squamous intraepithelial lesions (HSIL). The computer performed image tiling and fusing of multiple JPEG images to create a high-quality VM slide. Six examiners (two each of cytopathologists, senior residents, and cytotechnologists) blindly evaluated the VM slides using an image server program (WebSlide Browser thin client software). The cytopathologic diagnoses made on the VM slide were then compared to the original glass slide diagnoses. BLISS took 36-100 min (avg. 58.4 min) to scan the selected fields in a glass slide with file sizes ranging from 23.1-83.6 MB. Time taken by the examiners to render a diagnosis ranged from 1-15 min (avg. 4.1 min) per case. The combined diagnostic accuracy was 98.3%. Only one case of LSIL was missed by one examiner. VM is a promising new tool, which gives a user the feel and simulated experience of an actual microscopic examination and provides a useful alternative to a glass slide in diagnostic cytopathology. Possible applications include: 1) second opinion consultation without transporting the glass slide, 2) education, 3) VM proficiency tests / board exams, and 4) telepathology. Shortcomings include 1) expensive initial setup, 2) inability to maintain an adequate focus in a thick smear with multiple levels, 3) large storage size of the VM slide, and 4) relatively long time needed to scan a slide.

Telecytology: intraobserver and interobserver reproducibility in the diagnosis of cervical-vaginal smears

Telecytologic diagnosis of cervical-vaginal smears is potentially useful because it could allow more efficient use of cytopathologist resources and expertise. A pathologist in one location could, in principle, review cytotechnologists' findings using a video display hundreds or thousands of miles away. Currently, bandwidth restrictions limit practical implementation of such a system to review of fields that had been selected for review by the cytotechnologist. The purpose of our investigation was to evaluate how well this type of review correlates with a review in which the entire slide is available for examination by the pathologist. We prospectively selected 100 consecutive cervical-vaginal smears over an 11-day period in August 1999. For each smear, 4 to 12 fields containing abnormal cells from each slide were digitally imaged. Each of 3 pathologists reviewed all digitized images and all glass slides. Diagnoses based on selected digitized images were compared with those based on conventional pathologist review. The kappa statistic, a measure of chance-corrected agreement (reproducibility), was calculated in each setting. Overall, intraobserver and interobserver reproducibility of cervical-vaginal smear diagnoses is fair to excellent. The use of remote digital images for pathologist review did not introduce large (2-step) diagnostic disagreements. The disagreement between a pathologist's glass slide and digital diagnoses is less than that for different pathologists reviewing glass slides, although interobserver differences were even greater in the interpretation of digital images.

Telehematopathology in a clinical consultative practice

We studied a series of 60 telepathology cases sent in consultation to the Department of Hematopathology from January 1, 1995, through July 31, 2000. Cases from the United States and the world representing academic, private, military, and federal sectors were reviewed. Ninety percent of patients were adults (54 of 60), and male patients outnumbered female patients 2 to 1. Ages were from 1 to 79 years (mean, 42 years). Forty-three cases were lymph nodes (72%), 14 were bone marrow or peripheral blood (23%), and 3 were from other sites (5%). Twenty-seven of the consultant diagnoses were benign (27 of 60). Twenty-nine were malignant (non-Hodgkin lymphoma, Hodgkin disease, and "other malignancy" groups), and 4 were nondiagnostic. Glass slide/paraffin tissue blocks were available in only 35 (58%) of 60 cases. The concordance rate for diagnostic telehematopathology cases with subsequent glass slide/paraffin block follow-up was 91% (29 of 32 cases). The discordance rate was 9% (3 of 32). This finding shows a high degree of diagnostic accuracy for consultative telehematopathology. Of 118 images analyzed, 58 were considered very good/good (49%), 32 were poor/very poor (27%), and 28 were fair (24%). Poor images had suboptimal resolution, color, or technical quality of transmission, and most poor images were low-power images. Additional case problems included insufficient immunoperoxidase stain availability, selection, and labeling; transmitted field selection; specimen preparation and staining; presence or absence of accompanying clinical data; and availability of ancillary studies such as flow cytometric, cytogenetic, and molecular data. From this analysis, the following recommendations are offered. To optimize telehematopathology consultation, include any additional information that have a significant influence on the final consultant diagnosis. Include any pertinent clinical information, laboratory data, special stains, immunoperoxidase stains, and molecular data. Select representative and diagnostically significant low-power and high-power fields for an accurate diagnosis. Label every immunostain or special stain submitted. Always send glass slides and tissue blocks when requested by the consultant. Optimize telemedicine microscopy and computer equipment with appropriate technical expertise, training, and support. In conclusion, the field of telepathology offers an exciting and potentially powerful solution to the problem of national and global subspecialty consultation. Hematopathology is potentially well suited to this technologically advanced marriage of computer and Internet technologies with modern microscopy, molecular diagnostics, immunophenotypic profiling, and the consultant pathologist.

Characteristics of a telecytology consultation service

Although numerous reports describe the application of remote video microscopy to pathologic diagnosis (telepathology), only a few address some of the special issues surrounding remote cytologic diagnosis (telecytology). These studies have generally suggested a high correlation between telecytologic diagnoses and those arising from direct examination of the glass slides, but factors affecting the clinical utility of routine cytologic diagnosis have not been examined. In this report, we describe our experience in telecytologic consultation on 99 cases seen at the Armed Forces Institute of Pathology between October 1995 and November 1999. The mean time between receipt of the telecytologic images and the contributor receipt of the faxed report was 9.9 hours (median, 5.13 hours). Using stringent criteria for agreement, we find fair to good (48%) concordance between the contributor's impression and the consultant's opinion. The concordance between the consultant's telecytologic diagnosis and the subsequent glass slide diagnosis is imperfect; in 8 (31%) of 26 cases in which the glass slide was sent after the telecytology consultation, a minor discrepancy between these diagnoses was found. No major discrepancies were found between the consultant's telecytologic and glass slide diagnoses.

Clinical evaluation of an international static image-based telepathology service

Telepathology is the use of telecommunications technology as a means to facilitate transfer of image-rich pathology data between remote locations for the purposes of diagnosis, education, and research. Although varying levels of technology exist to accomplish this task, static image--based systems are currently the most widely used around the world. Field selection and image quality have often been identified as major impediments to the successful use of static images for diagnostic telepathology. Between November 1994 and July 1999, the Armed Forces Institute of Pathology (AFIP) performed electronic consultation on over 1,250 static image--based cases, recording a clinically significant concordance rate of 97.3% between telepathology and final diagnosis (in cases in which follow-up material was available). For the same subset of cases, an absolute concordance rate of 73.7% was attained. A review of the case flow and construction of the AFIP telepathology system is presented, as well as factors that have an impact on the diagnostic accuracy of static image-based telepathology sytems in general.

Telepathology overview: from concept to implementation

Telepathology is the practice of pathology at a distance by using video imaging and telecommunications. Significant progress has been made in telepathology. To date, 12 classes of telepathology systems have been engineered. Rapid and ultrarapid virtual slide processors may further expand the range of telepathology applications. Next-generation digital imaging light microscopes, such as miniaturized microscope arrays (MMA), may make virtual slide processing a routine laboratory tool. Diagnostic accuracy of telepathology is comparable with that of conventional light microscopy for most diagnoses. Current telepathology applications include intraoperative frozen sections services, routine surgical pathology services, second opinions, and subspecialty consultations. Three telepathology practice models are discussed: the subspecialty practice (SSP) model; the case triage practice (CTP) model; and the virtual group practice (VGP) model. Human factors influence performance with telepathology. Experience with 500 telepathology cases from multiple organs significantly reduces the video viewing time per case (P < .01). Many technology innovations can be represented as S-curves. After long incubation periods, technology use and/or efficiency may accelerate. Telepathology appears to be following an S-curve for a technical innovation.

Practical applications of Internet resources for cost-effective telepathology practice

Telepathology is the interpretation of digital microscopy images on a computer monitor at a significant distance from the location of original histology slides. Its use has proliferated globally and is part of routine practice in many laboratories. Even so, many perceive telepathology as requiring heavy initial capital expenditure. However, telepathology may be implemented in a wide variety of ways, some inexpensive. The limiting factor is often the technical knowledge and skill of the pathologist, not the technology or economics. The Internet is a versatile medium that may act as a repository of information in telepathology or as a communication conduit for either real-time (dynamic or robotic) or store-and-forward (static) methods. PubMed is an excellent starting point for literature research, with many journals providing full versions of their articles online to subscribers. However, these are largely in other fields of medicine and good online resources dedicated to telepathology techniques and information are less easily found. As a conduit for communication, the Internet can be the most economical option. Nearly every form of telepathology may use the Internet, provided there is sufficient bandwidth. Several techniques applied to general imaging may be used in store-and-forward telepathology. This article outlines some examples and discusses their relative merits.

An experimental inter-expert telepathology network using static imaging

AIMS

To set up a network for remote consultation using static imaging telepathology via Internet connection between pathologists in different European countries, and to collect some numerical and subjective impressions on the usefulness of this form of telepathology.

METHODS

A static image remote consultation network between 11 pathologists in nine European countries was set up; all pathologists were equipped with the same telepathology system. The pathologists formed three subject oriented subgroups concerned with prostate, melanoma, and soft tissue sarcoma pathology. Each pathologist sent and received a small number of cases, and data on each case were collected and analysed. The whole experiment was controlled through a World Wide Web site.

RESULTS

A total of 56 case consultations on 34 different cases were exchanged. The average case document contained seven images, and contained 1.97 Mbytes of data. For cases in which data were recorded, average case preparation and remote consultation time was 55 minutes and 9.2 minutes, respectively. Transmission times averaged 3.9 minutes. In subjective impressions, reservations were expressed in several cases regarding the confidence that could be given to the diagnosis from the images presented.

CONCLUSIONS

Remote consultation by telepathology via the Internet is now technically feasible and reasonably user friendly, but is only suitable as a method of disease diagnosis in some cases.

Clinical trial of telepathology as an alternative modality in breast histopathology quality assurance

Telepathology is a potential alternative to conventional histopathology. A clinical trial using a robotic telepathology system was conducted to assess the clinical and technical utility and effectiveness of telepathology in the U.K. breast screening pathology quality assurance program. Eighty-seven cases of breast disease were chosen at random from a series of 192 cases from the U.K. Breast Screening Pathology National Quality Assurance Scheme (NEQAS) collection. There were 20 benign, 23 carcinoma in situ (CIS), and 44 invasive malignant cases. The diagnostic accuracy of telepathology (TP) compared with conventional light microscopic (LM) diagnosis was 98.8%; this included a single case deferred for LM examination. The figure was similar when compared with expert consensus diagnosis (CD). In invasive tumor typing, TP accuracy was 95.4% (42/44 cases), the difference being attributable to slide color fading and would have had no impact on patient management. The accuracy of TP versus LM and expert consensus in tumor grading was 91.3% for carcinoma in situ (21/23 cases), a discordance with no relevance to patient management. TP grading of invasive tumor compared with LM diagnosis, had an accuracy of 86.4% (38/44) with a clinically significant accuracy of 97.7% (43/44). The time taken for TP diagnosis averaged 3.9 minutes per case by the end of the study. This data demonstrates that telepathology diagnostic accuracy is comparable to conventional microscopy and may therefore be envisaged as an alternative to conventional light microscopy for more rapid proficiency testing in breast screening (and perhaps other) quality assurance schemes.

The UICC Telepathology Consultation Center. International Union Against Cancer. A global approach to improving consultation for pathologists in cancer diagnosis

BACKGROUND

The morphologic diagnosis of tumor specimens with precise tumor typing, staging, and grading remains the basis of almost all cancer treatments. Thus, in each tumor case, a histologic diagnosis of the highest quality should be the physician's priority. In approximately 10-20% of tumor cases, diagnostic uncertainty remains to some degree, requiring a second opinion in determining the biologic behavior, the histogenesis, the grade of dedifferentiation, or any other parameter. Facilitating the communication between pathologists and the exchange of cases, telepathology gains more and more importance. To benefit from this technical development, the International Union Against Cancer (UICC) has decided to establish a Telepathology Consultation Center (UICC-TPCC) for interested pathologists around the world.

METHODS

The communication and exchange of histologic images works via the Internet. To ensure constant documentation, a case-based data base and image archive is used. Special TPCC software handles all requests to the TPCC and controls the interaction among requesting pathologists, TPCC, and UICC experts (transferring, reading, answering, logging, storing, etc.). All necessary data for controlling the telepathology service are stored in a customized SQL data base. The necessary equipment for the requesting pathologist is a personal computer; a digital or television camera/frame grabber, which is attached to a microscope; and access to the Internet. The requesting party contacts the TPCC's World Wide Web server and uploads the images and the clinical data of their case. To ensure uninterrupted functioning, the hardware will be part of a high-level communication center, which is connected via ATM (asynchronous transfer mode, 155 megabits per second) to the Internet.

RESULTS

The UICC has decided to establish the TPCC at the Institute of Pathology at the Charité, Humboldt-University, Berlin, Germany. The TPCC will not make the diagnoses itself but will involve an affiliated specialized expert pathologist. He or she will be on the panel of UICC experts who will constitute the "diagnostic backbone" of the TPCC. The center will function as follows: If a pathologist anywhere on the globe is confronted with the diagnosis of a difficult tumor case, he takes digitized histologic images (5-40 in number) and sends them along with sufficient clinical data to the server of the UICC-TPCC, asking for a second opinion. The center checks the case and transfers it to one of the UICC experts. This expert makes his or her diagnostic suggestion, which is then transferred back to the requesting pathologist via the UICC-TPCC.

CONCLUSIONS

The UICC-TPCC will be able to provide rapid and inexpensive diagnostic aid to pathologists all over the world, offering the possibility of a second opinion in accordance with the UICC-TNM and World Health Organization (WHO) standards. During the first and second year, the UICC-TPCC will be financed by sponsors. Telepathology makes the distribution of new developments of diagnostic standards, e.g., of the TNM system, WHO terminology, new tumor classifications, and updated information on actual technologies, globally accessible in a direct and rapid way. It also enables a high quality of education and teaching.

Telepathology: a diagnostic tool for the millennium?

Many developments in science have their origins in science fiction and telepathology is no exception. The concept was first illustrated in 1924 in the magazine 'Radio News'. It was not until 1980, however, that the first working telepathology system was demonstrated. Although the system was shown to work, it required special hardware, dedicated software and special microwave transmission links to be installed. Little interest was shown worldwide because of the very high cost and the inability of many people to replicate such a system. Ten years later, the personal computer (PC) was able to provide more than adequate performance at low cost for both image display quality and speed, and the development of video technology had resulted in high quality images being produced by television cameras that were now easily affordable. Microscopes were also relatively cheaper. Thus, by 1993 or 1994, all the hardware necessary to produce a telepathology system was available at reasonable cost. Telepathology can now be used for remote primary diagnosis, remote referral to a specialist pathologist, remote teaching, remote presentation of post-mortem or microscopic findings, quality assurance image circulation and feedback, and consensus diagnosis for pathological review in clinical trials. There are two residual problems. The first concerns the speed of data transmission, commonly referred to as the bandwidth. The second is that the software provided by most of the manufacturers and suppliers of these systems is not entirely suitable to the task and the systems are not interoperable. It is clear that the approach of the manufacturers is at present unlikely to produce telepathology systems which pathologists feel comfortable in using. A somewhat different approach is illustrated by the accompanying article in this issue from the Berlin group, where a relatively simple Java-based applet and the Internet are used to allow single or multiple users to view slides on a robotic microscope. This could form the basis for a truly useful system, but still needs modification for some applications.

"Virtual microscopy" and the internet as telepathology consultation tools: diagnostic accuracy in evaluating melanocytic skin lesions

The Internet offers a widely available, inexpensive tool for telepathology consultations. It allows the transfer of image and text files through electronic mail (e-mail) or file transfer protocols (FTP), using a variety of microcomputer platforms. We studied the use of the Internet and "virtual microscopy" tools for the diagnosis of 35 skin biopsies, including a variety of benign and malignant melanocytic lesions. Digitized images from these lesions were obtained at 40x and 100x optical magnification, using a high resolution digital camera (Microlumina, Leaf Systems, Southborough, MA), a light microscope with a phototube adapter and a microcomputer with a Pentium 166 MHz microprocessor. Two to four images of each case were arranged on a "canvas" to represent the majority or an entire biopsy level, using Photoshop software (Adobe Systems Inc., San Jose, CA). The images were compressed using Joint Photographers Expert Group (JPEG) format. The images were then viewed on a computer video monitor in a manner that closely resembles light microscopy, including scrolling by using the "hand tool" of Photoshop and changing magnification digitally up to 4 times without visible image degradation. The image files, ranging in size from 700 kilobytes to 2.1 megabytes (average 1.6 megabytes) were attached to e-mail messages that contained clinical information, using standard Multipurpose Internet Mail Extension (MIME) protocols and sent through the Internet, for interpretation by a dermatopathologist. The consultant could open the images from the e-mail message, using Microsoft Outlook Express (Microsoft Corp., Redmond, WA) and Photoshop software, scroll them, change magnification and render a diagnosis in a manner that closely simulates light microscopy. One hundred percent concordance was obtained between the telepathology and traditional hematoxylin and eosin slide diagnoses. The Internet and relatively inexpensive "virtual microscopy" tools offer a novel technology for dermatopathology consultations. Potential applications of this technology to pathology and technical problems posed by the use of an open, widely distributed network to share sensitive medical information are discussed.

Virtual microscopy: high resolution digital photomicrography as a tool for light microscopy simulation

Recent advances in microcomputers and high resolution digital video cameras provide pathologists the opportunity to combine precision optics with digital imaging technology and develop new educational and research tools. We review recent advances in virtual microscopy and describe techniques for viewing digital images using a microcomputer-based workstation to simulate light microscopic examination, including scanning at low power to select features of interest and zooming to increase magnification. Hardware and software components necessary to acquire digital images of histological and cytological slides, and closely simulate their examination under a light microscope are discussed. The workstation is composed of a MicroLumina digital scanning camera (Leaf Systems, Southborough, MA), light microscope (Olympus Optical Co., Lake Success, NY), Pentium (Intel Corp., Santa Clara, CA) 166 MHz microcomputer configured with 64 megabytes of random access memory (RAM), a MGA Millenium Powerdesk graphics card (Matrox Graphics, Inc., Montreal, Canada) and Photoshop software (Adobe Systems Inc., San Jose, CA) running in a Windows 95 (Microsoft Corp., Redmond, WA) environment. Images with spatial resolutions of up to 2700 x 3400 pixels in 36-bit color, can be displayed simultaneously as distinct images in a montage, or merged into a single composite image file to highlight significant features of a histological or cytological slide. These image files are saved in Joint Photographers Experts Group (JPEG) format using compression ratios of up to 80:1 without detectable visual degradation. The advantages and technical limitations of various workstation components are addressed and applications of this technology for pathology education, proficiency testing, telepathology, and database development are discussed.

Secure transmission of urologic images and records over the Internet

PURPOSE

Telemedicine has become a common method for the transmission of images and patient data across long distances. Our goal was to assess the efficiency and accuracy of Photomailer MD software, a store-and-forward telemedicine system, in the urologic setting.

METHODS

Photomailer MD software was loaded on two computers in the host institution, one with a T1 connection to the Internet and the other with a dial-up modem connection (24,000 bits/second), and computers at three remote sites. A total of 14 clinical cases, comprised of digitized histories and radiographic images, were sent to the remote institutions four separate times using the four transmission modes available: nonencrypted, 56-bit encryption, 128-bit encryption, and 128-bit encryption with password. The following data points were recorded: file size before and after encryption, file transmission times, and diagnostic accuracy of the remote urologists. One-way ANOVA was used to compare mean values statistically, while the z-test was used to compare diagnostic accuracies.

RESULTS

Encryption increased the file size by a mean of 37.8%, with the three encryption modes increasing file sizes by the same number of kilobytes. When a dial-up modem was used, encrypted files required a significantly longer transmission time (P < 0.05) than the unencrypted files. The same trend was seen with the T1 connection, although the differences often were not significant. When T1 transmission times were compared with modem times with other variables held constant, modem times were significantly longer (P < 0.05). Diagnostic accuracies for each of the three remote centers ranged from 85.7% to 100%. Differences in accuracy rates between attending physicians and residents were not significant.

CONCLUSIONS

Photomailer MD provides a secure, convenient, and affordable method of transmitting patient images and records via the Internet. Transmission speed was significantly greater when using a T1 line and also tended to be faster when files were not encrypted. There was no significant difference in transmission time among the three encryption modes; therefore, 128-bit encryption with a password should be used to maximize security. Diagnostic accuracies were comparable to those in the literature. In general, 640 x 480-pixel resolution was adequate for urologic diagnoses, although higher-resolution images may improve accuracy.

Atypical small acinar proliferation suspicious for malignancy in prostate needle biopsies: clinical significance in 33 cases

Prostate needle biopsies occasionally contain an atypical small acinar proliferation (ASAP) that is suspicious for, but not diagnostic of, adenocarcinoma. The histologic features and clinical significance of this finding are unexplored. We evaluated 33 cases of ASAP with at least one follow-up needle biopsy seen at Mayo Clinic from 1993 to 1996. Numerous histologic and clinical features were assessed to determine their predictive value for adenocarcinoma on subsequent biopsy. Mean patient age was 61.6 years (range 45-72). Adenocarcinoma was identified on follow-up biopsy in 15 of 33 patients (45%), with a median follow-up of 9 months (range 1-27). Gleason score varied from 4 to 7 (mean 5.9). Two patients (6%) had subsequent diagnoses of ASAP after one and three repeat biopsies. Digital rectal examination, serum prostate-specific antigen, and a variety of histologic findings were not predictive of cancer on follow-up biopsy. These histologic findings included number of biopsy cores (mean 5.5), number of acini per focus of ASAP (mean 7.9), number of foci (mean one), variation in acinar size, nuclear enlargement (none, 12% of cases; mild, 45%; moderate, 33%; severe, 10%), nucleolar enlargement (none, 27%; mild, 46%; moderate, 27%), luminal mucin (39%), crystalloids (6%), focal chronic inflammation (64%), adjacent atrophy (100%), and adjacent high-grade prostatic intraepithelial neoplasia (PIN) (42%). Stratification of suspicion in cases of ASAP without PIN into three categories ("favor benign, uncertain, and favor carcinoma") was somewhat predictive of subsequent cancer (20%, 25%, and 60% of cases with subsequent cancer, respectively), but the results were not significant. The high predictive value of ASAP for subsequent adenocarcinoma warrants repeat biopsy. No single clinical or pathologic feature appeared to increase the likelihood of subsequent cancer.

Diagnostic accuracy of an international static-imaging telepathology consultation service

Static-image and dynamic- (real-time) image telepathology are competing technologies. Although some studies suggest that the diagnostic accuracy of the dynamic-image telepathology approaches the accuracy of light microscopy, few reports have documented the diagnostic accuracy of static-image telepathology as used in the setting of an actual surgical pathology consultation practice. We report the results of an analysis of 171 telepathology consultation cases submitted to the Arizona-International Telemedicine Network (AITN). Digital images were submitted by pathologists from six participating institutions in Arizona, Mexico, and China. Telepathologists could render a telepathology diagnosis (TP) or defer rendering a diagnosis to obtain additional video images, glass slides for detailed analysis, or to obtain tissue blocks for special studies such as immunohistochemistry. The telepathologists rendered diagnoses for 144 cases and deferred 27 cases. Two pathologists retrospectively evaluated-glass slides from each case and rendered a consensus glass slide (GS) "truth" diagnosis. There was 88.2% concordance between TP and GS diagnoses (127 of 144 diagnoses). Concordance of 96.5% was achieved for clinically important diagnoses (139 of 144 diagnoses). Telepathologists deferred making a diagnosis to obtain glass slides for conventional light microscopy in 14 cases (8.1%) and for results of immunohistochemistry studies in 13 cases (7.6%). Thus, correct diagnoses were rendered by static-image telepathology in 127 of 171 cases (74.3%) at the time of telepathology diagnostic sessions. Inappropriate field selection and sampling biases of referring pathologists, as well as a tendency of static-image telepathologists to underestimate the complexity of some cases, may reduce the value of consultations based on the viewing of static images.