Comparison of virtual microscopy and glass slide microscopy among dermatology residents during a simulated in-training examination

Comparison of Digital Pathology and Light Microscopy Among Dermatology Residents: A Reappraisal Following Practice Changes

BACKGROUND

Following transition to digital pathology for primary diagnosis at our institution, dermatology residents have reduced exposure to light microscopy. This study compares resident competency with light microscopy versus digital pathology following practice changes.

METHODS

Twenty-one dermatology residents were administered a dermatopathology examination composed of 32 diagnoses evaluated using digital slides and 32 with light microscopy. Case difficulty was graded and balanced between modalities. Diagnostic accuracy was measured using the number of correct diagnoses for each modality. Participants were surveyed regarding their experience and preferences.

RESULTS

Diagnostic accuracy was higher with digital pathology than light microscopy (22/32 vs. 18/32, P < 0.001). Diagnostic accuracy with digital pathology increased with years of training, but accuracy with light microscopy did not. Residents with previous light microscopy experience achieved an average score of 19/32 on glass, as compared with 10/32 for those without experience (P = 0.039). Digital pathology was preferred over light microscopy (18/21, 85.7%).

CONCLUSIONS

Trainees had better diagnostic proficiency with digital pathology and preferred this modality. Most practices at this time continue to use light microscopy. Therefore, we need to maintain proficiency in microscopy during training while concurrently preparing trainees for a digital future.

Dermatology residents' perspectives on virtual dermatopathology education

BACKGROUND

Dermatopathology education accounts for 30% of U.S. dermatology residency training. The COVID-19 pandemic expedited the implementation of virtual dermatopathology in place of traditional microscopy for resident education. This study examined U.S. dermatology residents' perceptions of virtual dermatopathology, as research in this area is lacking.

METHODS

An anonymous, confidential, institutional review board-approved survey was electronically distributed to U.S. dermatology residents consisting of 16 questions comparing attitudes towards virtual and traditional dermatopathology education. Responses were n = 59. Statistical analysis was performed using SAS software.

RESULTS

Participants believe virtual imaging is superior to conventional microscopy in schedule flexibility (96.6% vs. 1.7%, p < 0.0001), lecture convenience (94.8% vs. 0.0%, p < 0.0001), personal review (96.6% vs. 0.0%, p < 0.0001), cost-effectiveness (64.4% vs. 6.8%, p < 0.0001), and board exam preparation (52.5% vs. 16.9%, p = 0.0005). Conventional microscopy was favored for image quality (50.8% vs. 25.4%, p = 0.0127) and overall utility (50.8% vs. 27.1%, p = 0.0195).

CONCLUSIONS

Our study supports virtual dermatopathology utilization as a valuable tool in dermatology residency training. Also it is shown that conventional microscopy training continues to play a key role. Further studies should examine whether, if ever, virtual dermatopathology could gradually replace conventional microscopy with the advent of newer and more powerful digital and scanning technology.

National resident survey in dermatopathology: The role of slide scanners in resident learning

BACKGROUND

Dermatology residents gain exposure to dermatopathology through a variety of educational modalities. While virtual pathology applications have risen dramatically, resident utilization of digital libraries, slide scanner availability, and comfort with virtual slides are not well-known. This study aims to assess the current landscape of educational resources used by dermatology residents.

METHODS

A 17-question survey was sent to dermatology residents through a national email database. The survey was a self-assessment of their experience in dermatopathology education and the use of departmental slide scanners.

RESULTS

The use of digital dermatopathology is high among trainees, despite only half of respondents reporting slide scanner access. Residents report using virtual images more often in non-clinical dermatopathology didactics and independent studies compared to clinical dermatopathology rotations. Public slide set use was common, while professional society and departmental slide sets may be underutilized. Over half of respondents report being extremely or very comfortable navigating interactive scanned slides.

CONCLUSIONS

Survey data suggests digital slides are currently predominantly used in non-clinical dermatopathology rotations and independent studies. Incorporation of slide scanners into departments may benefit resident education through the development of high-quality, curated departmental slide sets.

Comparison of four different displays for identification of select pathologic features extracted from whole slide images of surgical pathology cases

BACKGROUND

The establishment of minimum standards for display selection for the whole slide image (WSI) interpretation has not been fully defined. Recently, pathologists have increasingly preferred using remote displays for clinical diagnostics. Our study aims to assess and compare the performance of three fixed work displays and one remote personal display in accurately identifying ten selected pathologic features integrated into WSIs.

DESIGN

Hematoxylin and eosin-stained glass slides were digitized using Philips scanners. Seven practicing pathologists and three residents reviewed ninety WSIs to identify ten pathologic features using the LG, Dell, and Samsung and an optional consumer-grade display. Ten pathologic features included eosinophils, neutrophils, plasma cells, granulomas, necrosis, mucin, hemosiderin, crystals, nucleoli, and mitoses.

RESULTS

The accuracy of the identification of ten features on different types of displays did not significantly differ among the three types of "fixed" workplace displays. The highest accuracy was observed for the identification of neutrophils, eosinophils, plasma cells, granuloma, and mucin. On the other hand, a lower accuracy was observed for the identification of crystals, mitoses, necrosis, hemosiderin, and nucleoli. Participant pathologists and residents preferred the use of larger displays (>30″) with a higher pixel count, resolution, and luminance.

CONCLUSION

Most features can be identified using any display. However, certain features posed more challenges across the three fixed display types. Furthermore, the use of a remote personal consumer-grade display chosen according to the pathologists' preference showed similar feature identification accuracy. Several factors of display characteristics seemed to influence pathologists' display preferences such as the display size, color, contrast ratio, pixel count, and luminance calibration. This study supports the use of standard "unlocked" vendor-agnostic displays for clinical digital pathology workflow rather than purchasing "locked" and more expensive displays that are part of a digital pathology system.

Virtual Microscopy Goes Global: The Images Are Virtual and the Problems Are Real

For the last two centuries, the scholarly education of histology and pathology has been based on technology, initially on the availability of low-cost, high-quality light microscopes, and more recently on the introduction of computers and e-learning approaches to biomedical education. Consequently, virtual microscopy (VM) is replacing glass slides and the traditional light microscope as the main instruments of instruction in histology and pathology laboratories. However, as with most educational changes, there are advantages and disadvantages associated with a new technology. The use of VM for the teaching of histology and pathology requires an extensive infrastructure and the availability of computing devices to all learners, both posing a considerable financial strain on schools and students. Furthermore, there may be valid reasons for practicing healthcare professionals to maintain competency in using light microscopes. In addition, some educators may be reluctant to embrace new technologies. These are some of the reasons why the introduction of VM as an integral part of histology and pathology instruction has been globally uneven. This paper compares the teaching of histology and pathology using traditional or VM in five different countries and their adjacent regions, representing developed, as well as developing areas of the globe. We identify general and local roadblocks to the introduction of this still-emerging didactic technology and outline solutions for overcoming these barriers.

Applications of Telemedicine in Dermatology

Telemedicine is a technological tool that enhances well-being all around the globe. Practicing medicine or performing a clinical examination from a distance was a mere thought until this decade's pandemic hit the world. Telemedicine is practicing medicine sitting on one side of a globe and diagnosing and treating a different individual from the opposite part of the world. There is a long way to go for medical practitioners to execute an entire clinical examination analogous to an accurate clinical examination. Telemedicine is a supplement to a patient's total care, not a replacement for in-person doctor visits. Family doctors can easily access specialists using telemedicine, which enables them to monitor their patients closely. Numerous telemedicine systems, including store and forward, real-time and remote, or self-monitoring, are used worldwide for education, healthcare delivery and control, sickness screening, and disaster management. Even if telemedicine cannot solve every issue, it can significantly lessen the strain on the healthcare system. Nevertheless, investigations performed via telemedicine have started incorporating various medical instruments called telemedicine peripherals, including electronic stethoscopes, teleophthalmoscopes, and video-otoscopes. The prevailing disease around the globe of coronavirus has remarkably debilitated the medical infrastructure in providing diagnosis, treatment, monitoring, and follow-ups. As a result, there is a significant change in the way of practicing medicine and managing patients. Telemedicine provides timely patient care and reduces the risk of exposure to various communicable diseases offered to medical practitioners. The development of imaging technologies has significantly impacted dermatology, a specialty that relies on visual signals. Reviewing dermatology's existing situation and potential digital future, in brief, is the goal of this study. This study provides brief information on telemedicine, its application and scope in dermatology, and how it can alter the healthcare system.

Implementation of an interactive virtual microscope laboratory system in teaching oral histopathology

Laboratory course acts as a key component of histopathology education. Recent trends of incorporating visual and interactive technology in active and inquiry-based learning pedagogical methods have led to significant improvement of histopathology laboratory courses. The present work aimed to describe interactive virtual microscope laboratory system (IVMLS) as a virtual platform for teaching histopathology in order to improve the quality and efficiency of teaching. The system is based on interactive technology and consists of interactive software, slide-reading software, teaching resources and integrated auxiliary equipment. It allows real-time interaction between teachers and students and provides students with a wealth of learning and review materials. In order to evaluate the effectiveness of the system, we conducted a comparative study with the use of light microscope (LM) as a method. Specifically, we compared the results of six assignments and one laboratory final exam between IVMLS group and LM group to analyse the impact of IVMLS on students' academic performance. A questionnaire survey was also conducted to obtain students' attitudes and views on this system. There was no overall difference in assignment performance between IVMLS group and LM group. But laboratory final test grades increased from a mean of 62% (43.8–80.0, 95% CI) before to 83% (71.0–94.2, 95% CI) after implement IVMLS, suggesting highly significant (p < 0.001) improvement on students' histopathology laboratory performance. Feedback of the questionnaire was positive, indicating that students were satisfied with the system, which they believed improved student communication and teacher-student interaction, increased learning resources, increased their focus on learning, and facilitated their independent thinking process. This study proves that IVMLS is an efficient and feasible teaching technology and improves students' academic performance.

The use of digital microscopy as a teaching method for human pathology: a systematic review

Since digital microscopy (DM) has become a useful alternative to conventional light microscopy (CLM), several approaches have been used to evaluate students' performance and perception. This systematic review aimed to integrate data regarding the use of DM for education in human pathology, determining whether this technology can be an adequate learning tool, and an appropriate method to evaluate students' performance. Following a specific search strategy and eligibility criteria, three electronic databases were searched and several articles were screened. Eight studies involving medical and dental students were included. The test of performance comprised diagnostic and microscopic description, clinical features, differential, and final diagnoses of the specimens. The students' achievements were equivalent, similar or higher using DM in comparison with CLM in four studies. All publications employed question surveys to assess the students' perceptions, especially regarding the easiness of equipment use, quality of images, and preference for one method. Seven studies (87.5%) indicated the students' support of DM as an appropriate method for learning. The quality assessment categorized most studies as having a low bias risk (75%). This study presents the efficacy of DM for human pathology education, although the high heterogeneity of the included articles did not permit outlining a specific method of performance evaluation.

Optical Versus Virtual Microscope for Medical Education: A Systematic Review

Many technological innovations have changed the traditional practice of medical education and clinical practice. Whole slide imaging (WSI) technology provided an unique way of viewing conventional glass slides in histology and pathology laboratories. The WSI technology digitalized glass slide images and made them readily accessible via the Internet using tablets or computers. Users utilized the pan-and-zoom function to view digital images of slides, also referred to as the virtual microscope (VM), simulating use of an optical microscope (OM). Several articles have reported various outcomes on the utility of VM in teaching laboratories. Recently, the Royal College of Physicians and Surgeons of Canada certification examinations for anatomical pathologists ha completely adopted VM for the national licensing examination. To better inform medical educators, there is an urgent need for more structured reviews to draw evidence-based conclusions on the effectiveness of VM and learner's perceptions, in comparison to OM. The current study provides a descriptive summary of published outcomes using the systematic review approach. In conclusion, medical students' performance was improved with adoption of VM into the curriculum and recognized as a preferred learning modality, compared to OM. On the contrary, resident learners' performance was comparable between using OM and VM, with OM being the favored slide-viewing modality.

Emerging paradigm of virtual-microscopy for histopathology diagnosis: survey of US and Canadian oral pathology trainees

Objectives/Aims:

The application of virtual microscopy (VM) to research, pre-doctoral medical and dental educational training, and diagnostic surgical and anatomic pathology is well-documented but its application to the field of oral and maxillofacial pathology has not been explored. This is the first study to evaluate the enthusiasm and readiness of US-/Canada-based oral and maxillofacial pathology (OMFP) residents toward employing VM use over conventional microscopy (CM) for diagnostic purposes.

Materials and Methods:

All 46 current US-/Canada-based OMFP residents were invited to participate in an anonymous electronic survey via ‘Survey Monkey’ in 2015. The survey comprised sixteen multiple choice questions and two ‘free text’ questions.

Results:

14% of respondents of the 22 (48%) respondents who completed the survey indicated a willingness to substitute CM with VM in <5 years, and 33% within 10 years. 52% reported they would never substitute CM with VM. Approximately 10 and 57% of respondents thought VM will become an acceptable sole diagnostic tool in most centers within 5 and 10 years, respectively. These findings are irrespective of the fact that overall, 90% of respondents reported being familiar with VM use.

Discussion:

VM technology is unlikely to substitute CM in diagnostic oral and maxillofacial histopathology practice among future OMFP practitioners in the foreseeable future.

Feasibility study in teledermatopathology: An examination of the histopathologic features of mycosis fungoides and spongiotic dermatitis

BACKGROUND

Digital pathology offers numerous advantages, allowing remote information sharing using whole slide imaging (WSI) to digitize an entire glass slide (GS) at high resolution, creating a digital slide (DS).

METHODS

In this study, we examine the concordance in diagnoses made on 40 digital slides (DSs) vs traditional GSs in differentiating between spongiotic dermatitis (SD) and patch/plaque-stage mycosis fungoides (MF).

RESULTS

Greater interobserver concordance rate in final diagnosis of SD vs MF was observed with the utilization of DS (86.7%) compared with the utilization of GS (80%). Intraobserver concordance rate between the diagnoses rendered by a particular dermatopathologist on GS and DS was 86.7%. For all histopathological criteria, a correlation in the magnitudes of interobserver vs intraobserver discordances suggests that discordance between glass vs digital evaluation of these criteria may be largely expected subjective read variation independent of the media. Discordance in identification of histopathological features did not have a statistically significant link to discordance in diagnosis for 7 out of the 8 features.

CONCLUSIONS

The similarity between interobserver and intraobserver discordances suggests that WSI does not introduce additional barriers or variability to accurately identify histopathologic feature and to discriminate between MF and SD beyond interobserver variability.

An update on the validation of whole slide imaging systems following FDA approval of a system for a routine pathology diagnostic service in the United States

Pathologists have used light microscopes and glass slides to interpret the histologic appearance of normal and diseased tissues for more than 150 years. The quality of both microtomes used to cut tissue sections and microscopes has improved significantly during the past few decades, but the process of rendering diagnoses has changed little. By contrast, major advances in digital technology have occurred since the introduction of hand held electronic devices, including the development of whole slide imaging (WSI) systems with software packages that can convert microscope images into virtual (digital) slides that can be viewed on computer monitors and via the internet. To date, however, these technological developments have had minimal impact on the way pathologists perform their daily work, with the exception of using computers to access electronic medical records and scholarly web sites for pertinent information to assist interpretation of cases. Traditional practice is likely to change significantly during the next decade, especially since the Federal Drug Administration in the USA has approved the first WSI system for routine diagnostic practice. I review here the development and slow acceptance of WSI by pathology departments. I focus on recent advances in validation of WSI systems that is required for routine diagnostic reporting of pathology cases using this technology.

Dermatopathology education in the era of modern technology

Continuing technological advances are inevitably impacting the study and practice of dermatopathology (DP). We are seeing the transition from glass slide microscopy to virtual microscopy, which is serving both as an accessible educational medium for medical students, residents and fellows in the form of online databases and atlases, as well as a research tool to better inform us regarding the development of visual diagnostic expertise. Expansion in mobile technology is simplifying slide image attainment and providing greater opportunities for phone- and tablet-based microscopy, including teledermatopathology instruction and consultation in resource-poor areas with lack of specialists. Easily accessible mobile and computer-based applications ("apps"), including myDermPath and Clearpath, are providing an interactive medium for DP instruction. The Internet and social networking sites are enabling rapid global communication of DP information and image-sharing, promoting collaborative diagnostic research and scholastic endeavors.

A Systematic Analysis of Discordant Diagnoses in Digital Pathology Compared With Light Microscopy

CONTEXT

- Relatively little is known about the significance and potential impact of glass-digital discordances, and this is likely to be of importance when considering digital pathology adoption.

OBJECTIVE

- To apply evidence-based medicine to collect and analyze reported instances of glass-digital discordance from the whole slide imaging validation literature.

DESIGN

- We used our prior systematic review protocol to identify studies assessing the concordance of light microscopy and whole slide imaging between 1999 and 2015. Data were extracted and analyzed by a team of histopathologists to classify the type, significance, and potential root cause of discordances.

RESULTS

- Twenty-three studies were included, yielding 8069 instances of a glass diagnosis being compared with a digital diagnosis. From these 8069 comparisons, 335 instances of discordance (4%) were reported, in which glass was the preferred diagnostic medium in 286 (85%), and digital in 44 (13%), with no consensus in 5 (2%). Twenty-eight discordances had the potential to cause moderate/severe patient harm. Of these, glass was the preferred diagnostic medium for 26 (93%). Of the 335 discordances, 109 (32%) involved the diagnosis or grading of dysplasia. For these cases, glass was the preferred diagnostic medium in 101 cases (93%), suggesting that diagnosis and grading of dysplasia may be a potential pitfall of digital diagnosis. In 32 of 335 cases (10%), discordance on digital was attributed to the inability to find a small diagnostic/prognostic object.

CONCLUSIONS

- Systematic analysis of concordance studies reveals specific areas that may be problematic on whole slide imaging. It is important that pathologists are aware of these areas to ensure patient safety.

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

BACKGROUND

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

OBJECTIVE

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

METHOD

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

RESULTS

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

LIMITATIONS

Efficiency and other logistical WSI parameters were not evaluated.

CONCLUSION

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

Comparing whole slide digital images versus traditional glass slides in the detection of common microscopic features seen in dermatitis

BACKGROUND

The quality and limitations of digital slides are not fully known. We aimed to estimate intrapathologist discrepancy in detecting specific microscopic features on glass slides and digital slides created by scanning at ×20.

METHODS

Hematoxylin and eosin and periodic acid-Schiff glass slides were digitized using the Mirax Scan (Carl Zeiss Inc., Germany). Six pathologists assessed 50-71 digital slides. We recorded objective magnification, total time, and detection of the following: Mast cells; eosinophils; plasma cells; pigmented macrophages; melanin in the epidermis; fungal bodies; neutrophils; civatte bodies; parakeratosis; and sebocytes. This process was repeated using the corresponding glass slides after 3 weeks. The diagnosis was not required.

RESULTS

The mean time to assess digital slides was 176.77 s and 137.61 s for glass slides (P < 0.001, 99% confidence interval [CI]). The mean objective magnification used to detect features using digital slides was 18.28 and 14.07 for glass slides (P < 0.001, 99.99% CI). Parakeratosis, civatte bodies, pigmented macrophages, melanin in the epidermis, mast cells, eosinophils, plasma cells, and neutrophils, were identified at lower objectives on glass slides (P = 0.023-0.001, 95% CI). Average intraobserver concordance ranged from κ = 0.30 to κ = 0.78. Features with poor to fair average concordance were: Melanin in the epidermis (κ = 0.15-0.58); plasma cells (κ = 0.15-0.49); and neutrophils (κ = 0.12-0.48). Features with moderate average intrapathologist concordance were: parakeratosis (κ = 0.21-0.61); civatte bodies (κ = 0.21-0.71); pigment-laden macrophages (κ = 0.34-0.66); mast cells (κ = 0.29-0.78); and eosinophils (κ = 0.31-0.79). The average intrapathologist concordance was good for sebocytes (κ = 0.51-1.00) and fungal bodies (κ = 0.47-0.76).

CONCLUSIONS

Telepathology using digital slides scanned at ×20 is sufficient for detection of histopathologic features routinely encountered in dermatitis cases, though less efficient than glass slides.

The Diagnostic Concordance of Whole Slide Imaging and Light Microscopy: A Systematic Review

CONTEXT

-Light microscopy (LM) is considered the reference standard for diagnosis in pathology. Whole slide imaging (WSI) generates digital images of cellular and tissue samples and offers multiple advantages compared with LM. Currently, WSI is not widely used for primary diagnosis. The lack of evidence regarding concordance between diagnoses rendered by WSI and LM is a significant barrier to both regulatory approval and uptake.

OBJECTIVE

-To examine the published literature on the concordance of pathologic diagnoses rendered by WSI compared with those rendered by LM.

DATA SOURCES

-We conducted a systematic review of studies assessing the concordance of pathologic diagnoses rendered by WSI and LM. Studies were identified following a systematic search of Medline (Medline Industries, Mundelein, Illinois), Medline in progress (Medline Industries), EMBASE (Elsevier, Amsterdam, the Netherlands), and the Cochrane Library (Wiley, London, England), between 1999 and March 2015.

CONCLUSIONS

-Thirty-eight studies were included in the review. The mean diagnostic concordance of WSI and LM, weighted by the number of cases per study, was 92.4%. The weighted mean κ coefficient between WSI and LM was 0.75, signifying substantial agreement. Of the 30 studies quoting percentage concordance, 18 (60%) showed a concordance of 90% or greater, of which 10 (33%) showed a concordance of 95% or greater. This review found evidence to support a high level of diagnostic concordance. However, there were few studies, many were small, and they varied in quality, suggesting that further validation studies are still needed.

Digital slide viewing for primary reporting in gastrointestinal pathology: a validation study

Despite the increasing availability of digital slide viewing, and numerous advantages associated with its application, a lack of quality validation studies is amongst the reasons for poor uptake in routine practice. This study evaluated primary digital pathology reporting in the setting of routine subspecialist gastrointestinal pathology, commonplace in most tissue pathology laboratories and representing one of the highest volume specialties in most laboratories. Individual digital and glass slide diagnoses were compared amongst three pathologists reporting in a gastrointestinal subspecialty team, in a prospective series of 100 consecutive diagnostic cases from routine practice in a large teaching hospital laboratory. The study included a washout period of at least 6 months. Discordant diagnoses were classified, and the study evaluated against recent College of American Pathologists (CAP) recommendations for evaluating digital pathology systems for diagnostic use. The study design met all 12 of the CAP recommendations. The 100 study cases generated 300 pairs of diagnoses, comprising 100 glass slide diagnoses and 100 digital diagnoses from each of the three study pathologists. 286 of 300 pairs of diagnoses were concordant, representing intraobserver concordance of 95.3 %, broadly comparable to rates previously published in this field. In ten of the 14 discordant pairs, the glass slide diagnosis was favoured; in four cases, the digital diagnosis was favoured, but importantly, the 14 discordant intraobserver diagnoses were considered to be of minor clinical significance. Interobserver, or viewing modality independent, concordance was found in 94 of the total of 100 study cases, providing a comparable baseline discordance rate expected in any second viewing of pathology material. These overall results support the safe use of digital pathology in primary diagnostic reporting in this setting.

Comparison of the manual, semiautomatic, and automatic selection and leveling of hot spots in whole slide images for Ki-67 quantification in meningiomas

Background. This paper presents the study concerning hot-spot selection in the assessment of whole slide images of tissue sections collected from meningioma patients. The samples were immunohistochemically stained to determine the Ki-67/MIB-1 proliferation index used for prognosis and treatment planning. Objective. The observer performance was examined by comparing results of the proposed method of automatic hot-spot selection in whole slide images, results of traditional scoring under a microscope, and results of a pathologist's manual hot-spot selection. Methods. The results of scoring the Ki-67 index using optical scoring under a microscope, software for Ki-67 index quantification based on hot spots selected by two pathologists (resp., once and three times), and the same software but on hot spots selected by proposed automatic methods were compared using Kendall's tau-b statistics. Results. Results show intra- and interobserver agreement. The agreement between Ki-67 scoring with manual and automatic hot-spot selection is high, while agreement between Ki-67 index scoring results in whole slide images and traditional microscopic examination is lower. Conclusions. The agreement observed for the three scoring methods shows that automation of area selection is an effective tool in supporting physicians and in increasing the reliability of Ki-67 scoring in meningioma.

Whole slide imaging: uses and limitations for surgical pathology and teaching

Advances in computer and software technology and in the quality of images produced by digital cameras together with development of robotic devices that can take glass histology slides from a cassette holding many slides and place them in a conventional microscope for electronic scanning have facilitated the development of whole slide imaging (WSI) systems during the past decade. Anatomic pathologists now have opportunities to test the utility of WSI systems for diagnostic, teaching and research purposes and to determine their limitations. Uses include rendering primary diagnoses from scanned hematoxylin and eosin stained tissues on slides, reviewing frozen section or routine slides from remote locations for interpretation or consultation. Also, WSI can replace physical storage of glass slides with digital images, storing images of slides from outside institutions, presenting slides at clinical or research conferences, teaching residents and medical students, and storing fluorescence images without fading or quenching of the fluorescence signal. Limitations include the high costs of the scanners, maintenance contracts and IT support, storage of digital files and pathologists' lack of familiarity with the technology. Costs are falling as more devices and systems are sold and cloud storage costs drop. Pathologist familiarity with the technology will grow as more institutions purchase WSI systems. The technology holds great promise for the future of anatomic pathology.

Observer performance in the use of digital and optical microscopy for the interpretation of tissue-based biomarkers

BACKGROUND

We conducted a validation study of digital pathology for the quantitative assessment of tissue-based biomarkers with immunohistochemistry.

OBJECTIVE

To examine observer agreement as a function of viewing modality (digital versus optical microscopy), whole slide versus tissue microarray (TMA) review, biomarker type (HER2 incorporating membranous staining and Ki-67 with nuclear staining), and data type (continuous and categorical).

METHODS

Eight pathologists reviewed 50 breast cancer whole slides (25 stained with HER2 and 25 with Ki-67) and 2 TMAs (1 stained with HER2, 1 with Ki-67, each containing 97 cores), using digital and optical microscopy.

RESULTS

Results showed relatively high overall interobserver and intermodality agreement, with different patterns specific to biomarker type. For HER2, there was better interobserver agreement for optical compared to digital microscopy for whole slides as well as better interobserver and intermodality agreement for TMAs. For Ki-67, those patterns were not observed.

CONCLUSIONS

The differences in agreement patterns when examining different biomarkers and different scoring methods and reviewing whole slides compared to TMA stress the need for validation studies focused on specific pathology tasks to eliminate sources of variability that might dilute findings. The statistical uncertainty observed in our analyses calls for adequate sampling for each individual task rather than pooling cases.

Concordance between digital pathology and light microscopy in general surgical pathology: a pilot study of 100 cases

AIM

(1) A pilot study to determine the accuracy of interpretation of whole slide digital images in a broad range of general histopathology cases of graded complexity. (2) To survey the participating histopathologists with regard to acceptability of digital pathology.

MATERIALS AND METHODS

Glass slides of 100 biopsies and minor resections were digitally scanned in their entirety, producing digital slides. These cases had been diagnosed by light microscopy at least 1 year previously and were subsequently reassessed by the original reporting pathologist (who was blinded to their original diagnosis) using digital pathology. The digital pathology-based diagnosis was compared with the original glass slide diagnosis and classified as concordant, slightly discordant (without clinical consequence) or discordant. The participants were surveyed at the end of the study.

RESULTS

There was concordance between the original light microscopy diagnosis and digital pathology-based diagnosis in 95 of the 100 cases while the remaining 5 cases showed only slight discordance (with no clinical consequence). None of the cases were categorised as discordant. Participants had mixed experiences using digital pathology technology.

CONCLUSIONS

In the broad range of cases we examined, digital pathology is a safe and viable method of making a primary histopathological diagnosis.