Computer Assisted Education using Whole Slide Images (aka virtual slides/V.S.) Fred R. Dee, MD Department of Pathology The University of Iowa, Iowa City, Iowa Virtual slide education at Iowa has been supported by: Iowa College of Medicine Educational Developmental Funds Iowa Student Computing Fees Award Universities Associated for Research and Education in Pathology National Library of Medicine Information Systems Grants I have no financial or consultative relationship with any commercial entity, nor have I had any in the past. Outline of presentation Implementation in University of Iowa courses Histology for medical students Pathology for medical students Basics for decisions in education Cytology education Implementation in the AACR Pathobiology of Cancer Course Implementation in Iowa Courses 2000-2005 First year Histology (~110 annotated virtual slides + on-line syllabus) Virtual Histology Laboratory Heidger P, Dee FR, Consoer D, Leaven T, Kreiter C. An Integrated Approach to Teaching and Testing in Histology with Real and Virtual Imaging. The Anatomical Record (The New Anatomist) 269:107-112, 2002. Second year Pathology (stand alone two semesters 10 s.h.) Case Analysis Virtual Slidebox of Histopathology Dee (Dick) FR. Web-based Virtual Microscope Laboratories. Pathol Education 25:58-62, 2001. (a GRIPE publication) Kumar RK, Velan GM, Korell SO, Kandara M, Dee FR, Wakefield D. Virtual microscopy for learning and assessment in Pathology. Journal of Pathology 204:613-618, 2004. (in collaboration with Univ. of New South Wales) Case Analysis In lieu of of “Path Lab” we teach morphology in pathology case based learning exercises 22 two-hour sessions ~3-4 cases/week Eight students + one “facilitator” Students prepare cases before class (~2-4 hr) and then students present in small group Students examine ~70 slides in the 2 semester course Case Analysis content is integrated with about 76 lectures. Traditional Case Analysis materials 1970-1999 virtual version of Case Analysis 2000-2005 Preparation for small group before and after 2000 Students presenting in Case Analysis small group Virtual Slidebox of Histopathology www.path.uiowa.edu/virtualslidebox An atlas of 570 “core” virtual histopathology slides for medical students General Path slides are annotated Students use this resource to prepare for Case Analysis Independently study morphologic objectives that are not covered in Case Analysis Outcomes (Histology and Pathology) A significant increase in efficiency and accessibility expressed by both students and faculty. Increase in student skill in presenting morphologic findings on “slides” in Case Analysis (subjective evaluation by their facilitator) Students continue to learn traditional microscopy in Microbiology and Histology and are tested in histology No change in student performance on photomicrograph or glass slide exams Laboratory space utilization has markedly decreased. Student interest in Pathology as a career has increased Univ. of Iowa educational web interface Web pages are dynamically generated by Perl scripts from a MySQL database which contains: The name and location of the virtual slide file & viewer/server/annotator The address of gross and other jpeg images Multiple text entry fields All data content is entered into the database via a Perl scripted web-based editor The Perl scripts and database were developed in house. The virtual slide scanner (Aperio) and viewer/server/annotator (MicroBrightField) were purchased. Basics for decisions: Recommendations for other educators Slide Scanner Make certain the file format(s) output is non-proprietary and convertible to other formats. Serving and viewing: Should be able to view a number of file formats, especially non-proprietary ones Educational interface: Can be purchased from vendors (bundled with the viewer). Or create your own Advantage: you have not built your entire course around one vendor Keep it simple until there is more standardization in the industry. Why consider alternatives to traditional microscopy in teaching histology and Pathology? Laboratory time reduced in “new” curricula, virtual microscopy is more efficient and accessible Cost to replace and maintain microscopes and glass slides Competition for lab space From both computer labs and research labs The total cost for slides, microscopes, and space for a 50 student traditional laboratory is approximately $100,000 per year. What important traditional microscopy features are retained with virtual microscopy? Change magnification (zoom) and explore (pan) the entire section, independently find structures, discover relationships, and draw conclusions Focus (z-axis or 3-D) microscopy: microbiology, urinalysis, cytology Note: The above cannot be done with photomicrographs What can you do with traditional microscopy that you can’t with virtual microscopy? Teach students how to examine slides with a traditional microscope. See better detail at low power Other Discern refractiveness (e.g. eosinophil granules) Adjust image with condenser, diaphragm, polarizer What can you do with virtual microscopy that you can’t with traditional microscopy or video- microscopy? Computer assisted instruction Whole slide view (<<2.5x) The best or rare slides can independently be accessed and viewed by many Enhance image quality (sharpness and contrast) Computer assisted instruction Accessibility Removable media or the web. Efficiency Slides available at the click of mouse with proper light and condenser students can examine a larger number of slides in a shorter time. Interactivity Integrate into computerized Case Based Learning Links to gross, radiology, etc Side by side comparison with normal slides, etc Annotations for independent learning Other Self-assessment quizzes Computerized practical exams Display to large groups Should we completely abandon teaching traditional microscopy to medical students? No! Students need to have a concept of where the histological sections on a computer screen or in books and journals come from. Office practices frequently use microscopes for urine sediment, gram stains and blood smears Real microscopes are used in diagnostic pathology labs. Real microscopes are used in research labs. Will we have to partially or completely replace traditional microscope teaching laboratories? Probably, if it hasn‟t already happened Cytopathology Education Compelling reason to create cytology virtual slides Only one, or very few identical glass slides can be made –– especially applicable for testing and CE/CME. Special technical challenges Cytology cells do no lie flat on the slide thus z-axis (3- D) viewing is needed Light source must be adjustable to see into clumps of cells. The slide needs to be rapidly and systematically scanned by a technologist Revisit to previously identified cells is needed – i.e. marking Z-axis (3-D virtual focus) acquisition and viewing low- resolution/ low power Acquire multiple multi-resolution (pyramidal) image files 0.1u to 4u of focus apart, and perfectly aligned in high- the z-axis resolution/ high power pan and zoom, plus virtual focus by scrolling from one file to the next Cervical Cytology Education Project (NLM Funded project 2003-2006) Goals of the project Evaluate the effectiveness and validity of using virtual slides (V.S) in cervical cytology education, including testing and distance learning. Create a public assess educational web site Annotated atlas Locate and identify exercises Self-assessment Create a dataset of virtual cervical cytology slides which is freely available to educators Evaluation of diagnostic accuracy: Methods Stage 1: 2-D V.S. x-y axis (one level of focus) Web-based Stage 2: 3-D x-y-z axis V.S. (6 levels of focus) DVD-based 48 paid volunteer cytologists from 10 institutions 5 unknown slides V.S. covered about ¼ the „whole slide‟ of a liquid-based prep (at 40X) They examined the virtual side and committed to a Bethesda interpretation Then were given the glass slide, and added a glass slide diagnosis if different. Results Bethesda interpretations were reduced to 4 categories: negative, low grade, high grade, and endometrial carcinoma Diagnostic accuracy (2-D & 3-D were combined) Individual glass slide Dx. vs. consensus glass slide Dx. 95% Individual V. S. Dx. vs. individual glass slide Dx. 90% Individual V.S. Dx. vs. consensus glass slide Dx. 92% Most V.S. „mis-diagnoses‟ were under-calls Subjective evaluation Speed: ~5 minutes /glass slide ~7 minutes for virtual slide (2-D & 3-D) (¼ of the whole slide) Navigation and image quality: 3-D was more strongly endorsed than 2-D There was significant frustration with the inability to focus on all cells with 2-D slides. Suitability for education and testing: There was little support for using V.S. (even 3-D) for the yearly CLIA mandated proficiency testing. 3-D was strongly endorsed for distance education/CME 3-D would be an improvement on the BOR certifying exam which currently uses photomicrographs Virtual slides in cervical cytology Education: Summary Diagnostic accuracy is ~5% less than with glass slides Although diagnostic accuracy and speed were no different for 2-D and 3-D virtual slides, the subjective evaluation markedly favored 3-D. There was enthusiasm for the concept of using 3-D virtual slides in education and some testing. In the Locate and Identify exercises the learner locates and marks abnormal cells on the virtual slide, identifies them with text, enters an interpretation; and when finished, compares side-by-side the identical slide marked and interpreted by an expert. The Multiple choice examination evaluates learning. AACR Pathobiology of Cancer Workshop Laboratories (for graduate students) Goal : To evaluate the use of virtual slides vs. digital photomicrographs for teaching histopathology to students in a traditional pathology microscope laboratory setting Structured similar to Pathology Laboratories in many Medical schools 6 two-hour labs with: 18 students per lab 10-20 glass slides per lab (105 glass slides total) A microscope for each student Gross displays and photographs Faculty Illustrate slide content Circulate in the lab Human Pathology 34:430-436, 2003. The AACR Pathobiology of Cancer Workshop Laboratories Evaluation design: Students continued to use and learn from glass slides and a microscope in all labs. Variable: Virtual slides were created and used to illustrate slide content in one of the 6 labs (Genitourinary cancer) In the remaining 5 labs, slide content continued to be illustrated with photomicrographs by 2x2 carousel or PowerPoint. An AACR Workshop Laboratory Results (98 students) Compared to the traditional teaching technology used in the other laboratories (i.e. photomicrographs) the virtual slides… Strongly Agree About Disagree Strongly agree the same disagree Were of high image quality and resolution 59 21 4 0 0 Enhanced the instructor’s ability to point out cells and lesions that you were expected to see on the glass slide 79 9 1 0 0 Enhanced your overall ability to learn from the glass slides at the microscope 63 14 6 1 0 Results Students comments: “This definitely helped with identifying lesions better than normal projector slides” “It really helped to have instructors find structures” “I was better able to identify the specific features on my (glass) slide” “The digital equivalent of a multi-headed microscope” On the other hand, several students suggested that virtual slides projected in lab by faculty “can make you lazy” and some students “didn‟t look in detail at their own slides”.