Effect of Display Resolution on Time to Diagnosis with Virtual Pathology Slides in a Systematic Search Task

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

Telepathology: frozen section diagnosis at a distance

Telepathology may be used to provide a frozen section service to hospitals without a department or institute of pathology. We have developed a telepathology system using the commercially available Integrated Services Digital Network (ISDN). The main software and hardware elements of our system are: Apple Macintosh workstations, a program for simultaneous transfer of image, voice and data, and a data bank for storage of patients' data and microscopic images. A picture instrument manager (PIM) makes remote control of microscopes or other instruments possible. The system connects the Department of Pathology of the University of Basel with the Regional Hospital of Samedan, 250 km away, and the Regional Hospital of Burgdorf, 100 km away. During a period of 20 months, frozen sections with the hospitals in Samedan and Burgdorf were performed in 53 patients. Between 54 and 58 s were required for the transfer of a diagnostic 8-bit grey level image containing 341±26.1 (standard error) kbytes (n=13) or a diagnostic 24-bit colour image containing 165±16.9 kbytes (n=40). Frozen section diagnosis was completed in 20–40 min. True-positive diagnoses of malignant tumours were achieved in 85.7% of cases (sensitivity=0.857). No false-positive diagnosis was made. In 3 of the 53 cases telepathological diagnosis was not possible for technical reasons.     

Telepathy: maximizing resident exposure to surgical pathology decision making

BACKGROUND: General surgery residents are often not present for the critical intraoperative discussion between surgeon and pathologist regarding surgical pathology findings. METHODS: A prospective pilot study analyzed general surgery resident exposure to surgical pathology. Thereafter, an operating room was equipped to view frozen section images in real time and verbally communicate with the pathologist (TelePATHy). Total operative cases, cases using frozen sections, and use of TelePATHy were recorded. RESULTS: Most residents (78%) reported they were exposed to frozen-section surgical pathology < or =10% of the time. Overall, 202 operations were performed over the 123-day period. Forty-four cases had frozen-section specimens. General surgery residents were present for 40 cases. TelePATHy was successfully used in 32 cases (80%). CONCLUSIONS: General surgery resident exposure to intraoperative pathology findings increased from a reported < or =10% to an observed 80%. TelePATHy is a novel intraoperative tool capable of maximizing the intraoperative experience of the surgical resident.     

Assessment of diagnostic accuracy and feasibility of dynamic telepathology in China

To assess the feasibility, including diagnostic accuracy and time cost, of a real-time telepathology system with pathologic slides, 600 cases covering a wide spectrum of lesions from 16 organ systems were tested. The "correct" diagnosis (gold standard) was established as a consensus by 2 experienced pathologists. The cases were first examined by 4 pathologists at different levels of experience with dynamic telepathology. Cases were then reviewed by the same pathologists using light microscopy in a blinded fashion 3 weeks to 2 months later. A diagnosis, together with reading times for telepathology and light microscopy, was recorded for each case. Diagnostic accuracy by telepathology was 94.8% (569/600), 93.3% (560/600), 91.6% (550/600), and 97% (388/400) for pathologists A, B, C, and D, respectively. Telepathologic diagnosis was concordant with the gold standard and with direct microscopy, with a mean of 94.2% and 99.26%, respectively. Most cases (510 or 85%) were diagnosed in 15 to 40 minutes by telepathology, with a mean of 17.0 minutes. The time needed to review a slide by telepathology was 3 to 4 times longer than that of standard light microscopy. All 4 pathologists were able to render a diagnosis in all cases. Our results showed that robotic telepathology is sufficiently accurate for primary diagnosis in surgical pathology, but modifications in laboratory protocols, telepathology hardware, and internet speed are needed to reduce the time necessary for diagnosis by telepathology before this method may be deemed suitable for use in a busy practice.     

Utility of whole slide imaging and virtual microscopy in prostate pathology

Whole slide imaging (WSI) has been used in conjunction with virtual microscopy (VM) for training or proficiency testing purposes, multicentre research, remote frozen section diagnosis and to seek specialist second opinion in a number of organ systems. The feasibility of using WSI/VM for routine surgical pathology reporting has also been explored. In this review, we discuss the utility and limitations of WSI/VM technology in the histological assessment of specimens from the prostate. Features of WSI/VM that are particularly well suited to assessment of prostate pathology include the ability to examine images at different magnifications as well as to view histology and immunohistochemistry side-by-side on the screen. Use of WSI/VM would also solve the difficulty in obtaining multiple identical copies of small lesions in prostate biopsies for teaching and proficiency testing. It would also permit annotation of the virtual slides, and has been used in a study of inter-observer variation of Gleason grading to facilitate precise identification of the foci on which grading decisions had been based. However, the large number of sections examined from each set of prostate biopsies would greatly increase time required for scanning as well as the size of the digital file, and would also be an issue if digital archiving of prostate biopsies is contemplated. Z-scanning of glass slides, a process that increases scanning time and file size would be required to permit focusing a virtual slide up and down to assess subtle nuclear features such as nucleolar prominence. The common use of large blocks to process prostatectomy specimens would also be an issue, as few currently available scanners can scan such blocks. A major component of proficiency testing of prostate biopsy assessment involves screening of the cores to detect small atypical foci. However, screening virtual slides of wavy fragmented prostate cores using a computer mouse aided by an overview image is very different from screening glass slides using a microscope stage. Hence, it may be more appropriate in this setting to mark the lesional area and focus only on the interpretation component of competency testing. Other issues limiting the use of digital pathology in prostate pathology include the cost of high quality slide scanners for WSI and high resolution monitors for VM as well as the requirement for fast Internet connection as even a subtle delay in presentation of images on the screen may be very disturbing for a pathologist used to the rapid viewing of glass slides under a microscope. However, these problems are likely to be overcome by technological advances in the future.