Use of remote video microscopy (telepathology) as an adjunct to neurosurgical frozen section consultation

Telemedicine Utilization in an Outpatient Pediatric Neurosurgical Clinic: A Prospective Survey of Patient and Family Preferences

OBJECTIVE

After becoming widespread during the COVID-19 pandemic, telemedicine continues to play an important role in outpatient neurosurgical care. Nevertheless, the factors that influence individual decisions to choose telemedicine versus in-person appointments remain understudied. Here, we performed a prospective survey of pediatric neurosurgical patients and caregivers presenting for telemedicine or in-person outpatient visits, to identify factors associated with appointment choice.

METHODS

All patients and caregivers with an outpatient pediatric neurosurgical encounter at Connecticut Children's between January 31st and May 20th, 2022, were invited to participate in this survey. Data related to demographics, socioeconomics, technological access, COVID-19 vaccination status, and appointment preferences were collected.

RESULTS

During the study period, there were 858 unique pediatric neurosurgical outpatient encounters (86.1% in-person and 13.9% telemedicine). A total of 212 (24.7%) respondents completed the survey. Those with a telemedicine appointment were more likely to be white (P = 0.005), not Hispanic or Latino (P = 0.020), have private insurance (P = 0.003), be established patients (P < 0.001), have a household income >$80,000 (P = 0.005), and have caregivers who completed a 4-year college degree (P < 0.001). Those who were seen in-person cited the patient's condition, quality of care, and communication as important factors, whereas those who were seen via telemedicine cited time, travel, and convenience.

CONCLUSIONS

While convenience influences some to choose telemedicine, concerns regarding the quality of care persist among those who prefer in-person encounters. Recognizing these factors will minimize barriers to care, better define the appropriate populations/contexts for each encounter type, and improve the integration of telemedicine within an outpatient neurosurgical setting.

[Remote intraoperative frozen section diagnosis in pathology with high definition video transmission through YouTube and Twitch]

INTRODUCTION

Remote diagnosis of frozen sections is an important asset for hospitals that do not have full-time pathologists. Ongoing advances in information technology are constantly being incorporated and we have used real time high-definition video.

MATERIAL AND METHODS

Our microscope was connected to a video camera with a 1080p resolution and its signal sent to the computer where OBS software encoded and transmitted video streams to YouTube and Twitch distribution platforms.

RESULTS

The high-quality image thus achieved allows an accurate, remote evaluation of frozen sections. Access through web pages allows them to be reviewed anywhere from any device with an Internet connection.

DISCUSSION

Remote intraoperative diagnosis is a challenge for pathologists and image quality is a critical requirement for its implementation, which can be solved by video streaming technology. The proper training of technicians is essential. This system can also be applied to many other areas of pathology, such as teaching and consultation.

Predictors of Telemedicine Utilization in a Pediatric Neurosurgical Population During the COVID-19 Pandemic

OBJECTIVE

In the wake of the COVID-19 pandemic, telemedicine has become rapidly adopted by the neurosurgical community; however, few studies have examined predictors of telemedicine utilization. Here, we analyze patient variables associated with the acceptance of a telemedicine encounter by a pediatric neurosurgical population during the early phases of the COVID-19 pandemic.

METHODS

All patients seen in a single institution's outpatient pediatric neurosurgery clinic between April 1, 2020 and July 31, 2020 were retrospectively reviewed. Demographic variables were collected for each patient's first completed encounter. Patients participating in telemedicine were compared with those seen in person. Univariate analysis was performed using the Wilcoxon rank sum test for continuous variables and Fischer exact test for categorical variables. A logistic regression multivariable analysis was then performed.

RESULTS

We included 682 patients (374 telemedicine and 308 in person). Univariate analysis demonstrated that telemedicine visits were more likely to occur at earlier study dates (P < 0.001) and that patients participating in telemedicine visits were more likely to be established rather than new patients (P < 0.001), White or Caucasian (P < 0.001), not Hispanic or Latino (P < 0.001), English-speaking (P < 0.001), non-Medicare/Medicaid recipients (P < 0.001), have lower no-show rates (P = 0.006), and live farther from the hospital (P = 0.005). Multivariable analysis demonstrated older age (P = 0.031), earlier appointment date (P < 0.01), established patient status (P < 0.001), English-speaking (P < 0.02), and non-Medicare/Medicaid insurance (P < 0.05) were significant predictors of telemedicine utilization.

CONCLUSIONS

Significant demographic differences exist among pediatric patients who participated in telemedicine versus those who requested an in-person visit at our institution. Addressing barriers to access will be crucial for promoting health equity in continued utilization of telemedicine.

The Next Generation Robotic Microscopy for Intraoperative Teleneuropathology Consultation

Introduction

Teleneuropathology at our institution evolved over the last 17 years from using static to dynamic robotic microscopy. Historically (2003-2007), using older technology, the deferral rate was 19.7%, and the concordance was 81% with the final diagnosis. Two years ago, we switched to use hybrid robotic devices to perform these intraoperative (IO) consultations because our older devices were obsolete. The aim of this study was to evaluate the impact this change had on our deferral and concordance rates with teleneuropathology using this newer instrument.

Materials and Methods

Aperio LV1 4-slide capacity hybrid robotic scanners with an attached desktop console (Leica Biosystems, Vista, CA, USA) and GoToAssist (v4.5.0.1620, Boston, MA, USA) were used for IO telepathology cases. A cross-sectional comparative study was conducted comparing teleneuropathology from three remote hospitals (193 cases) to IO neuropathology consultation performed by conventional glass slide examination at a light microscope (310 cases) from the host hospital. Deferral and concordance rates were compared to final histopathological diagnoses.

Results

The deferral rate for IO teleneuropathology was 26% and conventional glass slide 24.24% (P = 0.58). The concordance rate for teleneuropathology was 93.94%, which was slightly higher than 89.09% for conventional glass slides (P = 0.047).

Conclusion

The new hybrid robotic device for performing IO teleneuropathology interpretations at our institution was as effective as conventional glass slide interpretation. While we did observe a noticeable change in the deferral rate compared to prior years, we did appreciate the marked improvement of the concordance rate using this new hybrid scanner.

Systematic Review of the Use of Telepathology During Intraoperative Consultation

OBJECTIVE

To compare studies that used telepathology systems vs conventional microscopy for intraoperative consultation (frozen-section) diagnosis.

METHODS

A total of 56 telepathology studies with 13,996 cases in aggregate were identified through database searches.

RESULTS

The concordance of telepathology with the reference standard was generally excellent, with a weighted mean of 96.9%. In comparison, we identified seven studies using conventional intraoperative consultation that showed a weighted mean concordance of 98.3%. Evaluation of the risk of bias showed that most of these studies were low risk.

CONCLUSIONS

Despite limitations such as variation in reporting and publication bias, this systematic review provides strong support for the safety of using telepathology for intraoperative consultations.

Review of the use of telepathology for intraoperative consultation

INTRODUCTION

The use of telepathology in intraoperative consultations has been increasing due to limited time and availability of pathologists, and the demand for increased access to pathology subspecialists in difficult cases. The five main categories of telepathology are (1) static, (2) dynamic, (3) robotic, (4) whole slide imaging (WSI), and (5) hybrid methods. The majority of these methods have been found to offer diagnostic accuracy rates similar to conventional microscopy, at the cost of slightly prolonged time to evaluate slides.

AREAS COVERED

Herein we discuss the salient features of each telepathology method and provide examples of their performance reported in the literature.

EXPERT COMMENTARY

Telepathology systems from any of the aforementioned categories can be employed to achieve timely and accurate diagnoses as long as they meet clinical needs and are validated for the intended use case. The decision to purchase a particular system depends on the clinical application, specific needs and budget of the laboratory, as well as the personal preference of the telepathologists involved. The adoption of telepathology practice is likely to expand in order to meet the increasing demand for subspecialist consultation and as technology advances to improve diagnostic accuracy and workflow.

Frozen section evaluation via dynamic real-time nonrobotic telepathology system in a university cancer center by resident/faculty cooperation team

Frozen section telepathology interpretation experience has been largely limited to practices with locations significantly distant from one another with sporadic need for frozen section diagnosis. In 2010, we established a real-time nonrobotic telepathology system in a very active cancer center for daily frozen section service. Herein, we evaluate its accuracy compared to direct microscopic interpretation performed in the main hospital by the same faculty and its cost-efficiency over a 1-year period. From 643 (1,416 parts) cases requiring intraoperative consultation, 333 cases (690 parts) were examined by telepathology and 310 cases (726 parts) by direct microscopy. Corresponding discrepancy rates were 2.6% (18 cases: 6 [0.9%] sampling and 12 [1.7%] diagnostic errors) and 3.2% (23 cases: 8 [1.1%] sampling and 15 [2.1%] diagnostic errors), P = .63. The sensitivity and specificity of intraoperative frozen diagnosis were 0.92 and 0.99, respectively, in telepathology and 0.90 and 0.99, respectively, in direct microscopy. There was no correlation of error incidence with postgraduate year level of residents involved in the telepathology service. Cost analysis indicated that the time saved by telepathology was $19,691.00 over 1 year of the study period, whereas the capital cost for establishing the system was $8,924.00. Thus, real-time nonrobotic telepathology is a reliable and easy-to-use tool for frozen section evaluation in busy clinical settings, especially when frozen section service involves more than one hospital, and it is cost-efficient when travel is a component of the service.

Telepathology Impacts and Implementation Challenges: A Scoping Review

CONTEXT

Telepathology is a particular form of telemedicine that fundamentally alters the way pathology services are delivered. Prior reviews in this area have mostly focused on 2 themes, namely technical feasibility issues and diagnosis accuracy.

OBJECTIVES

To synthesize the literature on telepathology implementation challenges and broader organizational and societal impacts and to propose a research agenda to guide future efforts in this domain.

DATA SOURCES

Two complementary databases were systematically searched: MEDLINE (PubMed) and ABI/INFORM (ProQuest). Peer-reviewed articles and conference proceedings were considered. The final sample consisted of 159 papers published between 1992 and 2013.

CONCLUSIONS

This review highlights the diversity of telepathology networks and the importance of considering these distinctions when interpreting research findings. Various network structures are associated with different benefits. Although the dominant rationale in single-site projects is financial, larger centralized and decentralized telepathology networks are targeting a more diverse set of benefits, including extending access to pathology to a whole region, achieving substantial economies of scale in workforce and equipment, and improving quality by standardizing care. Importantly, our synthesis reveals that the nature and scale of encountered implementation challenges also varies depending on the network structure. In smaller telepathology networks, organizational concerns are less prominent, and implementers are more focused on usability issues. As the network scope widens, organizational and legal issues gain prominence.

Application of telepathology for neuropathologic intraoperative consultations

The demand for expert neuropathologic intraoperative diagnoses often exceeds the available supply and geographic distribution of neuropathology centers. Telepathology has therefore been implemented in recent years to meet this demand. Herein, we draw on our experience with 4 generations of telepathology systems over the past 8 years to discuss the design, initiation and maintenance of an effective telepathology service for neuropathologists, including when to change systems. In addition to workflow efficiency, unique advantages of telepathology include integration into other informatics modalities, quality assurance/quality control (QA/QC) maintenance and the potential for visual data to be readily available to clinicians. Given the improvements in technology and the multiple uses of telepathology, this method for delivering patient care will undoubtedly continue to grow over time.

Comparison of telepathology systems in neuropathological intraoperative consultations

Telepathology has emerged in recent years as a viable solution for providing rapid expert subspecialty consultations to geographically dispersed sites. The Neuropathology Division at the University of Pittsburgh Medical Center has utilized telepathology systems for the past 7 years to perform intraoperative consultations for neurosurgeons at a separate hospital. In 2007 the division switched to a next-generation dynamic robotic system with additional features, including higher resolution, faster image transmission speed, fine-focus control using the mouse fingerwheel, and multiple slide holding capacity. The diagnostic outcomes from a total of 262 intraoperative consultations performed using this new system are compared with 159 consultations using the prior system in 2006 and with outcomes from over 900 conventional consultations from 2006-2008. These results show that telepathology can be used to diagnose challenging tumors, and that differences in outcomes are as much a function of the different surgeries performed at different sites as is the diagnostic modality used.

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.

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.

Telemedicine and neurosciences

It is well known that in most countries there is a perennial shortage of specialists in neurosciences. The available neurologists and neurosurgeons are clustered in the metropolitan, urban areas. Those living in suburban and rural areas may have limited or no access to neurological care. Concurrently, there has been an unprecedented growth in information and communication technology (ICT). In this article, the author will demonstrate how the practice of neurosciences will change, with increasing use of telemedicine and ICT. In addition to presenting the author's personal experience, the literature on telemedicine in neurosciences is reviewed.

Intérêt de la télépathologie dans le diagnostic rapide des spécimens neurochirurgicaux

To determine whether still digital images of neurosurgical specimens sent by e-mail are an effective and safe way of obtaining an emergency pathological diagnosis, representative images from 48 neurosurgical smear specimens were digitized, compressed and sent by electronic mail to our consultant neuropathologist with relevant clinical and radiological information. The time to select, digitize, compress and send the images for each case was recorded. Comparison was made between diagnosis made from digital images (DI) and historical smear (HS) using the original permanent section (PS) diagnosis as the gold standard. A diagnosis of normal vs. abnormal, neoplastic vs. non-neoplastic, primary vs. secondary and tumor grade was made in each case. The mean time for selection and digitalization of each case was 9.51 minutes. The number of correct pathological diagnosis was 41/48 using DI and 48/48 using HS, giving an accuracy rate of 85.4% and 100% respectively. DI was 100% sensitive in recognizing neoplastic tissue but only 98% specific. Most inaccuracies were in grading and caused by problems with field selection and familiarity with the technique. We conclude that static digital images are reliable and safe method of interpreting tissue during neurosurgical procedures. This corresponds with the findings of previous studies.

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.

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.

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.

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.

Robotic telepathology for intraoperative remote diagnosis using a still-imaging-based system

The aim of the present study was to assess whether a telemicroscopy system based on static imaging could provide a remote intraoperative frozen section service. Three pathologists evaluated 70 consecutive frozen section cases (for a total of 210 diagnoses) using a static telemicroscopy system (STeMiSy) and light microscopy (LM). STeMiSy uses a robotic microscope, enabling full remote control by consultant pathologists in a near real-time manner. Clinically important concordance between STeMiSy and LM was 98.6% (95.2% overall concordance), indicating very good agreement. The rates of deferred diagnoses given by STeMiSy and LM were comparable (11.0% and 9.5%, respectively). Compared with the consensus diagnosis, the diagnostic accuracy of STeMiSy and LM was 95.2% and 96.2%. The mean viewing time per slide was 3.6 minutes, and the overall time to make a diagnosis by STeMiSy was 6.2 minutes, conforming to intraoperative practice requirements. Our study demonstrates that a static imaging active telepathology system is comparable to dynamic telepathology systems and can provide a routine frozen section service.

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.

Case triage model for the practice of telepathology

OBJECTIVE

To implement and evaluate a practice model for telepathology.

METHODS

A case triage practice model was devised in which general pathologists review all cases and refer them to subspecialists only when necessary. In 1993, the Arizona-International Telemedicine Network (AITN), a high-resolution static imaging telepathology diagnostic network, linking six sites to the University of Arizona in Tucson, began testing the model. Work flow through the network was analyzed, and diagnostic concordance was assessed in 150 surgical cases by comparing the diagnoses of the referring (transmitting) pathologists with diagnoses of the consulting (receiving) telepathologists as well as by comparing the referring pathologists' diagnoses with the consensus diagnoses reached by an independent review panel. Data analysis was controlled for subspecialty case type. Telepathologists had access to the referring pathologists' preliminary diagnoses, and the review panel had access to the original glass slides and the surgical pathology reports prior to rendering their respective diagnoses.

RESULTS

The triage pathologist completed the telepathology consultation without the assistance of a subspecialty pathologist in 66% of the cases. The review panel examined the original glass slides from 134 cases by light microscopy. Concordance rates of the telepathologists' or review panel's diagnoses with the referring pathologists' diagnoses were not statistically different (93.1% v 83.6%, respectively; P > 0.05).

CONCLUSION

The case triage model is suitable for the practice of telepathology. It significantly reduces the need for subspecialty pathologists. Static imaging telepathology is useful and reasonably efficient for rendering diagnostic opinions in the majority of referred cases. Tissue sampling limitations imposed by static imaging occasionally resulted in diagnostic errors.

Current issues in telepathology

Telepathology involves rendering diagnostic opinions on specimens at remote locations using computer and telecommunications technologies. Consultations are a routine practice pattern in pathology, as there is a large amount of diagnostic and prognostic information available from the examination of biopsy material that requires an extensive knowledge of diseases and their clinical implications. Pathologists therefore frequently request opinions from those who subspecialize in various diseases. The use of video technology to examine and consult on microscopical slides has been validated, although sparsely and with a number of technical issues as yet unresolved. There are two principal paradigms for telepathology: remote dynamic screening by robotic video microscopy and remote diagnosis from selected still video microscopical images. The former is more appealing to most pathologists; however, it requires very high speed telecommunications links that are expensive and may not be available in a given location. The latter method entails a significant reduction in the data on which the diagnosis is rendered, as one is dependent on the fields selected at the remote location. In addition, there are hybrid systems that combine limited robotic capabilities with high-resolution still images. Image compression can increase the number of images that can be transmitted over an otherwise-limiting telecommunications infrastructure. JPEG is the current standard for such compression. Despite certain limitations, telepathology has been demonstrated successfully at several sites around the world. As this technology matures, systems will offer higher resolution, standardization of file formats, and better compression at lower cost.

Telemicrobiology: feasibility study

BACKGROUND

Rural hospitals generally lack staffing with infectious disease specialists or pathologists. Without on-site pathologists, the range of microbiology services offered by clinical laboratories may be limited as well.

OBJECTIVE

To study the feasibility of using static-image telepathology to evaluate Gram stains of microbiologic preparations.

MATERIALS AND METHODS

In this retrospective feasibility study, three pathologists evaluated Gram stains of slides from 50 cases by two viewing modalities: static-image telepathology and conventional light microscopy. Digital video images of slides were captured at two magnifications (using 40x and 100x objective lenses) at 1024 x 768 x 24-bit color and transmitted over standard telephone lines at 14,400 kbps. Pathology reports and culture results served as "truth diagnoses." Categories of interpretations were correct, minor discrepancy, or major discrepancy with regard to the implications for patient care.

RESULTS

The diagnostic accuracy of video image readings and conventional light microscopy readings were nearly identical, with no statistically significant differences in the performances of specialty and nonspecialty pathologists (P > 0.05). The mean accuracies of readings of the video images and light microscopy images were 95.3% and 95.4%, respectively. Taking into account the time required by a referring pathologist to capture video digital images, telemicrobiology was somewhat less efficient than conventional light microscopy.

CONCLUSIONS

Pathologists can accurately evaluate digital video images of preselected fields on Gram-stained slides. In clinical practice, however, a limiting factor may be the availability of local personnel qualified to select the microscopic fields for evaluation by telepathologists. The adequacy of the video images suggests that telepathology may also be used for remote supervision of quality assurance programs in microbiology laboratories, as well as for remote proficiency training of laboratory personnel.

Diagnostic accuracy of a rural live video telepathology system

Accuracy of diagnoses rendered using a live video telepathology network was assessed for permanent sections of surgical pathology specimens. To determine accuracy, telepathology diagnoses were compared with those obtained by directly viewing the glass slide using a standard microscope. A total of 294 cases were read via both telepathology and glass slide by attending pathologists at a tertiary care medical center. Overall accuracy was defined as exact concordance between diagnoses. Clinically insignificant differences in diagnoses were excluded to determine clinically significant accuracy. For the 285 cases with complete data, the overall accuracy for telepathology was 0.912 (95% confidence interval [CI], 0.872-0.941), whereas the overall accuracy for glass slide readings was 0.968 (95% CI, 0.939-0.985). This difference is statistically significant (p = 0.009). When focusing on clinically significant discrepancies, where the difference in diagnosis might affect therapeutic decisions, the video accuracy was only slightly less than the glass slide accuracy (0.965 [95% CI, 0.934-0.982] vs. 0.982 [95% CI, 0.957-0.994], respectively), but this difference is not statistically significant (p = 0.302). Most of the cases with clinically significant differences involved lesions with inherently high interobserver variation. Certainty of diagnosis did not differ between video and glass slide readings (p = 0.911), but there was an association between certainty of diagnosis and diagnostic accuracy for video (p = 0.003 for clinically significant accuracies). Based on these findings, we recommend when using this telepathology system that only preliminary diagnoses should be given in the following situations: for diagnostic areas with known high interobserver variability; when the consultant has any degree of uncertainty about the presence or absence of the lesion in question; and when there is insufficient experience using telepathology as a diagnostic medium.

Static image analysis of skin specimens: the application of telepathology to frozen section evaluation

Although the ability to transmit high-resolution images of histopathological sections could have a profound impact on the practice of pathology, the application of video microscopy to the daily activities of surgical pathology has not been rigorously evaluated. In particular, certain aspects of video microscopy relating to frozen section evaluation have not been adequately assessed. We conducted a retrospective analysis of 48 excisional skin biopsy specimens encompassing a spectrum of benign and malignant lesions. To simulate an actual frozen section evaluation, only original frozen section slides were evaluated. Fields were selected and digitized (Roche Image Analysis System) by a pathology resident. Two sets of diagnoses were subsequently rendered by a surgical pathologist, the first set based on the digitized images and the second based on direct microscopic examination of the histological slides. The two sets of diagnoses were compared, and the concordance rates were as follows: malignant diagnoses, 100%; benign diagnoses, 100%; positive margins, 96%; negative margins, 99%. One (4%) of the 25 positive margins was indexed as negative by image analysis. Conversely, one (1%) of the 121 negative margins was indexed as positive by image analysis. In both of these cases, error was attributable to selection and digitization of an inappropriate field. We conclude that telepathology of static images is an accurate method of evaluating frozen sections of skin lesions. Potentially, this technology could be applied to the frozen section evaluation of other lesions as well. Static image analysis is, however, susceptible to errors induced by inappropriate field selection, emphasizing the need for trained and skillful personnel on both sides of the video camera.

Telepathology diagnosis of prostrate needle biopsies

We conducted a prospective analysis of the diagnostic accuracy of a static-image telepathology system (Roche RIAS, Elon College, NC) in the interpretation of needle biopsies of the prostate (NBx). Two hundred consecutive cases received in consultation were included. Each case was examined by one of the researchers (MHW), and images were captured either according to the areas of concern designated by the referring pathologist (set A; 100 cases) or according to the judgment of MHW (set B; 100 cases). The other researcher (JIE) daily rendered diagnoses first on the video images and then by direct microscopy. Accuracy of video diagnosis was categorized as 0 (correct), 1 (minor error), 2 (major error), or 3 (deferred). An average of 5.49 images were captured per case in set A, and 5.28 for set B. Seventy-seven, 9, 9, and 5 cases were categorized as 0, 1, 2, and 3, respectively, for set A, and 78, 17, 1, and 4 cases, respectively, for set B. Video versus direct diagnoses for the type 2 errors were five carcinoma versus markedly atypical, two carcinoma versus atypical, one carcinoma versus nonspecific granulomatous prostatitis, and two benign versus atypical. In these difficult NBx, telepathology allowed an essentially correct diagnosis in almost all of the cases. The number of images required was reasonable, and the images were of excellent quality. However, the accuracy varied from set A to set B, with the fractions of nondeferred cases that were given an essentially correct video diagnosis totaling 91% and 99%, respectively (P < .01). Accuracy of telepathology diagnosis using static images may depend on the person capturing the images, even in the case of small biopsies.

Transcontinental consults in surgical pathology via the Internet

An efficient and inexpensive electronic system to submit surgical pathology cases in consultation via the Internet is presented. A transcontinental pilot study showed a high degree of concordance between the diagnosis provided by the consultant on the basis of the pathology images and that given after examining the corresponding microscopic slides.

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.

Telepathology diagnosis by means of digital still images: an international validation study

Telepathology affords the means to provide pathological diagnosis and consultation to remote sites. However, before telepathology can become an acceptable medical tool, it will be vital to determine the diagnostic accuracy of this technology. We report the results of a single-blind study of the accuracy of diagnosis performed using computerized still images obtained from a telepathology workstation used in a French telepathology network. Four pathologists, each working alone, reviewed a total of 200 cases of routine surgical pathology (50 cases each), and performed diagnosis based on both computer CD-ROM still images (CD) and conventional glass slides (GS). Concordance between GS and CD diagnosis, as well as accuracy, were determined. Other factors related to performance were also measured, including diagnostic certainty, reasons for uncertainty, and causes of diagnostic error. Overall, there was good agreement between CS and CD diagnosis. There was 87.5% concordance between CS and CD diagnosis, and comparison to consensus (correct) diagnosis showed accuracy of 95.5% and 88.5% for GS and CD diagnosis, respectively. Marked variability in accuracy of CD diagnosis was observed among the four pathologists, and issues related to image selection and/or quality appeared responsible for 60% of the diagnostic errors. The lack of sufficient images and clinical information were frequently cited as reasons for diagnostic uncertainty, as well as feelings of insufficient expertise. It is likely that the opportunity for interaction with the referring pathologist and the use of subspecialty consultants would likely improve the performance of telepathology.

Current status of telepathology

Telepathology is moving from the experimental stage to become a regular feature of pathology practice. This has been made possible by technical advances in telecommunications and image processing. Since 1990 the University Hospital of Tromsø has provided local hospitals in northern Norway with a remote frozen section service and with access to video conferences for the review of microscopic findings and for the discussion of major diagnostic issues. Several other hospitals in Norway are now participating in this development and practical relations among pathology laboratories for the purpose of consultation and education will be the next step in the procedure. Similar developments in telepathology have taken place in other countries. Standardization of network and telepathology workstations will be needed before extensive international collaboration can be achieved. Progress in high quality video devices, high capacity telecommunication lines and improved image compression techniques will increase the usage of telepathology services and make them cost-effective. Thus, telepathology will contribute to the development of pathology services in the next century.