laboratory courses in the anatomical disciplines (Fitzharris, 1998 ... courses, general histology for medical students, and .... Adobe Photoshop. Edited tiff images.
THE ANATOMICAL RECORD (NEW ANAT.) 269:107–112, 2002
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Integrated Approach to Teaching and Testing in Histology With Real and Virtual Imaging PAUL M. HEIDGER, JR,* FRED DEE, DANIEL CONSOER, TIMOTHY LEAVEN, JAMES DUNCAN, CLARENCE KREITER
AND
The University of Iowa College of Medicine histology teaching laboratory incorporates extensive Web- and computerbased teaching modalities, including the Virtual Microscope (VM), as emerging learning aids in histology and pathology laboratory instruction. We report here our experience in offering a multiple resource-based approach to laboratory instruction while retaining the opportunity and requirement of examining actual microscopic slide preparations with the microscope. Acceptance of this approach has been high among our students and faculty, and performance levels established over years of teaching histology by traditional means have been maintained. Anat Rec (New Anat) 269:107–112, 2002. © 2002 Wiley-Liss, Inc. KEY WORDS: education; histology; microscope; virtual microscope; computer-assisted learning; CAL; medical curriculum; survey; teaching
INTRODUCTION In recent years, major revisions within the medical teaching curricula of many institutions have placed se-
Dr. Heidger is Professor of Anatomy and Cell Biology in the University of Iowa College of Medicine, has directed medical and graduate histology at Iowa for several years, and has been recognized by both the students and the university for teaching excellence and curricular innovation. Dr. Dee, Professor of Pathology in the College of Medicine directs the Pathology course at Iowa, and as a Curriculum Director has been a leader in the revitalization of the Iowa medical curriculum. Mr. Consoer is the research assistant and computer resource person responsible for acquiring and digitizing specimens and for overseeing the day-to-day maintenance and operation of the Virtual Microscope Laboratory and the Virtual Slide Box of Histology projects. Mr. Leaven of the Pathology Department created the HTML design for the Virtual Microscope. Mr. Duncan, MLIS, directs the Information Commons Computer Laboratories at the Hardin Library for Health Sciences. Dr. Kreiter is an Assistant Professor, Department of Family Medicine, and Consultant with the Office of Consultation and Research in Medical Education and has participated in data evaluation. *Correspondence to: Paul M. Heidger, Jr., Department of Anatomy and Cell Biology, University of Iowa College of Medicine, Iowa City, IA 52242. Fax: 319-335-7198; E-mail: paul-heidger@uiowa. edu DOI 10.1002/ar.10078 Published online in Wiley InterScience (www.interscience.wiley.com).
© 2002 Wiley-Liss, Inc.
vere constraints upon the time allocated to the teaching of traditional laboratory courses in the anatomical disciplines (Fitzharris, 1998; Hightower et al., 1999; Cotter, 2001). Specifically at the University of Iowa College of Medicine, a 30% reduction in laboratory contact time in histology was mandated when the departmentally based courses, general histology for medical students, and medical physiology, were folded into a single structure/function course entitled human organ systems (HOS). The strength of such courses, in concept, is the integrated presentation in one setting of structure/function concepts and the application of factual material within a clinical context with the aid of clinician/scientists lecturing in the course. Included among the many practical challenges of such curricular offerings is coordination and avoidance of duplication of effort and material presented by participating faculty drawn from diverse basic science and clinical backgrounds. Testing is another critical area of concern, if student evaluation is to be accomplished successfully in an optimally integrated manner, by using carefully constructed USMLE board-format, clinical vignette questions. And, certainly, not least among the challenges is maintaining a hands-on laboratory
experience sufficient to ensure that students cement lecture concepts in the laboratory and are well-prepared for the pathology laboratory course that follows in their second year. At Iowa, histology offers the only laboratory experience in HOS. The faculty in physiology and biophysics discontinued its animal teaching/demonstration laboratory some years ago but has recently reintroduced computersimulated group tutorials in the cardiac, respiratory, and renal physiology instructional units. Creative approaches to accommodate such reduced time allocations for teaching histology at other institutions have included early attempts at using 35 mm projection slides in selfstudy modules (Bauer et al., 1976); a variety of virtual and multimediabased approaches, including QuickTime VR and other computer applications (Trelease et al., 2000; Cotter, 2001); laser disc image banking technology (Downing, 1995); photomicrographic image banking with bar-code retrieval (Olgivie, 1995); and digitized photomicrographic exhibits derived from, and linked to, traditional laboratory slide sets (McMillan, 2001). At the University of Iowa, several initiatives have been undertaken by the histology faculty to increase efficiency of presentation and mastery of
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Figure 1. Screen shot of a Virtual Microscope (VM) Laboratory Web page. Depicted in the upper-left frame of the screen is a scan-power, “whole mount” view of the specimen (seminal vesicle) as it appears on the original glass microscope slide. The box overlay indicates the area of the slide digitized and, therefore, capable of being retrieved on the VM. Underlying this frame is the slide description taken from the lab syllabus for the convenience of the student. Also in this frame is the Web address to the General Histology Slide Index, which gives one-click access to the labeled collection of photomicrographs taken of the same slide. The large frame to the right is the working screen of the Virtual Microscope. Navigational tools (lower left) permit manipulation of the virtual slide. Six levels of magnification (1.25⫻; 2.5⫻; 5⫻; 10⫻; 20⫻; and 40⫻) are possible, starting at the scan view presented. A “click and drag” feature permits translation of the image across its full dimension, at any selected magnification, closely simulating stage movement capability of the traditional microscope.
traditional slide box material. These have included detailed prelaboratory orientations preceding all laboratory sessions; creation of an archival 35 mm Histology Image Index on the departmental and course Web sites of all slides presented in the prelaboratory sessions; and creation of an interactive teaching Web site, Histology!, to supplement the laboratory experience. Still further reduction in formal laboratory contact time has been achieved this past year by using the Virtual Microscope (VM), as conceived by Fred Dee and colleagues at Iowa, the methodology and initial evaluation of which has been reported previously (Harris et al., 2001). Our continuing experience with this methodology is the subject of the present report.
METHODOLOGY A detailed explanation of the methodology of collecting, processing, and presenting images with the Virtual Microscope is contained in our earlier paper (Harris et al., 2001). Since the appearance of this earlier report, we have digitized all slides from our comprehensive histology student slide col-
lection of nearly 130 slides and demonstration preparations. The slides were digitized by using MicroBrightField Virtual Slice software (www. microbrightfield.com) interfaced with a Leica DM microscope, Ludl motorized stage with auto-focus, Optronics videocamera, and Pentium III computer with 2 GB of RAM. Editing of tiff images was accomplished by using Adobe Photoshop. Edited tiff images were subsequently saved and highly compressed in a FlashPix image file format (fpx), by using MGI software (www.mgisoft.com). Delivery of the fpx files to the Web in standard HTML frames is accomplished by using MGI server software. The images may then be opened by using Windows with Internet Explorer or Netscape. A viewer plug-in (free from the MGI site) allows navigation of the images through several zoom levels of magnification (1.25 through 40⫻), as well as translation through the x-y axis of the image at any magnification. In addition to the digitized tissue specimen, each Web page displays a reduced image of the entire glass microscope slide with a box designating the region of the slide that has been digitized, together with a copy of the slide description
contained in the Histology Laboratory Manual. Figure 1 depicts a typical Web page layout and image. A demonstration of virtual slides may be viewed at the following Web address: http://128. 255.152.44/cgi-bin-pub/fpx_search.cgi
COURSE LOGISTICS: PAST AND PRESENT Careful coordination of the physiology and histology lectures in our course ensures that a lecture or series of lectures on the structural features of an organ or organ system precedes both the physiology lectures on the topic and the accompanying laboratory exercise. We stress the desirability to students, therefore, of faithful lecture attendance, as well as attendance at the prelaboratory, or “lab warm-up” session immediately preceding the assigned laboratory. These are conducted in a lecture room convenient to the laboratory by the histology faculty member leading the unit of study and consist of approximately 20-min reviews of structural features and hallmark identifiers of the tissues or organs to be studied in the particular laboratory session. This presentation is accomplished by an integrated
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presentation of Virtual Microscope images and 35 mm slides of the slide box material, cataloged in our Histology Image Index, which is also easily intranet accessible through the VM Web page or the HOS class Web page. In an effort to promote efficiency of study, particular attention is given to orienting the students to those portions of the slides that will yield the information or structures called for in the Histology Laboratory Manual. These prelaboratory sessions also allow our graduate assistants to gain experience in presenting before a large group of students. Having had the general region to be studied (and extraneous fat, artifact, and other histologic pitfalls to be avoided) explained to them, our students are enabled to move more efficiently and effectively through the day’s laboratory objectives. This approach frees them—and the faculty and graduate assistants—to spend more time in small group or individual discussions about structure/function relationships and the clinical significance of the material under study. The Histology Laboratory Manual is a traditional compilation of study objectives and features to be found on the slides available for study, written by the course faculty. Thought-questions and structure/function correlates are also included within the text of the manual. Importantly to the students, the manual also includes a list of testable lab objectives, which guide the faculty in the selection of laboratory practical examination questions. Immediately before the melding of the medical histology and physiology courses into the unified structure/ function course, human organ systems, the histology course consisted of 64 h of laboratory and 32 h of lecture, for a total of 96 contact hours over one semester. Under the HOS structure, histology is allotted 22 lectures covering basic morphology of cells, tissues, and organs, together with 13, two-h labs, over the course of the semester. Therefore, the formal contact hours total 48. However, the increased flexibility for student individual, small group, or home study on the Web has reduced the hours that most students spend in the laboratory. This is seen as positive in the sense that prior preparation on the Virtual
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Microscope Web site or other computer-based materials enhances efficiency when examining slides with the microscope. One advantage of selfstudy capability and less frequent laboratory attendance is that our faculty no longer must teach duplicate lab sessions as in the past, just to accommodate the number of students capable of being seated in our teaching facilities (labs and electronic classrooms) at any one time. Our teaching staff consists of five professors who team-teach both the lecture and laboratory portions of the course, assisted in the laboratory by three senior graduate students. A concise textbook is required, as are an atlas of histology and laboratory syllabus. Up to the point of dismissal from
Careful coordination of the physiology and histology lectures in our course ensures lectures on the structural features of an organ system precede both the physiology lectures on the topic and the accompanying laboratory exercise. introductory prelaboratory sessions, the students’ laboratory day does not differ appreciably from that experienced by the preceding 20 or more classes of medical students. However, with the increased emphasis on computer-based learning in histology has evolved the option of three venues for laboratory, chosen by students on the basis of their personalized study preferences and learning styles. Two venues, the Ingram Learning Center in Anatomy and Cell Biology and the Electronic Classrooms of the Information Commons at the Hardin Library for the Health Sciences, emphasize study of the material by using the Virtual Microscope, the labeled Web images of our Histology Slide Index, and the interactive histology Web site
Histology!, developed as a joint effort of our teaching faculty in medical and dental histology. Several commercially available CD-ROM and laser disc compilations of histology images are licensed for campus use (e.g., HistoTime, Stephen Downing) and serve as important supplements to our own collection of images. Importantly, each of these venues has quality binocular microscopes and slide sets that may be set up between computer stations for simultaneous study of real and virtual images. The third venue, the Pathology Learning Center, offers these same capabilities, in addition to multi-port microscopes and small conference room settings equipped with microscope image projectors, as well as projected Web image capability. The latter are used extensively by students engaging the faculty in small group learning, and for group review. Groups are not assigned; not infrequently, the study partners from the preceding semester in gross anatomy choose to team up in learning microscopic anatomy, as well. The sequence of learning the lab material that is encouraged by the faculty and adopted by most students is as follows: 1. Attending lecture and prelaboratory (which is highly recommended) . 2. Acquainting oneself with the material through the labeled slides of the Histology Image Index, in concert with study of the slides with the Virtual Microscope. 3. Transferring this information and extending observations by using real imaging and the through-focus capability of the light microscope, either individually, or at the multiport teaching scopes. 4. Reviewing the material repeatedly by using the “instant access” to the Virtual Histology Lab over the Web at home or any of the campus learning centers. 5. Expanding familiarity with a diversity of histo-images by using Web sites from sister institutions, the histology image banks, and virtual microscope images digitized from institutions participating in our database, The Virtual Slide Box of Histology.
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6. Self-testing using our interactive site Histology! and small group microscope or projected VM images. 7. Passing histology with honors(!) and hopefully gaining a deeper appreciation not only of structural biology but of the functions subserved by these structures.
TESTING FORMAT AND RESULTS Over several years, our histology course administered three practical exams. The first covered basic cell and tissue concepts, and the second and third addressed the histology of organs and organ systems. The third examination included an approximate 10% comprehensive component, principally concentrating on challenging tissue identifications, and not organspecific concepts. All examinations consisted of combinations of projected 35 mm Kodachrome slides and glass microscope slides examined individually by students with the microscope. This testing format continued after the incorporation of histology into HOS until last year, when we embarked upon computer-based testing for the unit examinations and maintained a microscope and glass slide comprehensive final examination. Each faculty member responsible for a given teaching unit digitized images from a variety of sources, and these were presented individually by means of computer to students in the electronic classroom settings available to us. Identifications of cells, tissues, and organs were required from these images, as were statements of structure/ function correlates. The tests were timed, initially on a 1-min-per-image basis (from our experience with giving a lock-step, 1 min at each microscope station in the traditional lab-testing venue). However, in response to student input (see later discussion), the later practicals were designed to give students flexibility in the time spent on each identification/response, with a total time allotted equal to 1 min per question. Images were presented one at a time, and students were not permitted to return to images once a response was selected. Students were required to write their responses on answer sheets provided, and these were hand-graded to ensure that syn-
onyms and misspellings did not result in loss of credit (as might be the case in using an expanded multiple choice format) and so that partial credit might be assigned when deserved. A distinct advantage of this format of testing is the ease with which make-up examinations may be given, and the ability to “bank” testable images over a period of years. No critical study of paired student responses on computer-administered vs. traditionally administered examinations has been made. However, the mean of the practical examinations for the preceding 3 years was 86%, and students scored within a percent or two of this mean on each of the computer-administered examinations. We empirically concluded that the mode of administration had no obvious effect on student performance, and embraced the ease of setup and administration, and the prospect of building a large image bank for future use in testing.
STUDENT PERCEPTIONS OF TEACHING AND LEARNING As reported by us previously (Harris et al., 2001), students rated the availability, ease of use, and quality of imaging with the VM highly in our formative evaluation conducted after the introduction of the VM capability into our laboratory teaching 2 years ago. Full implementation this past year of the VM as an option for studying and learning histology elicited similar enthusiastic acceptance, as judged by class responses to an optional course evaluation administered at the close of the semester, with 40% of the class responding. Table 1 summarizes numerical student ratings of several parameters. The rating scale was 1 ⫽ unacceptable; 2 ⫽ poor; 3 ⫽ fair; 4⫽ good; and 5 ⫽ excellent. Data are expressed as means, with both the range of responses and standard deviations indicated. In addition to providing numeric ratings, the students were encouraged to submit comments, some of which are included in the discussion of the Tables.
Traditional Microscope In Table 1A are recorded student perceptions with respect to quality and
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educational value of using the traditional student microscope. Responses supported that resolution and ease of use were favorable, but overall educational value was rated fair to good. It is noteworthy that the range of responses to this item touched both extremes— unacceptable and excellent! Students with microscope experience offered that “although the computer videodisks are often more convenient for studying purposes, the microscope (traditional or VM) is still an important learning tool.” For another, “More microscope practice should be encouraged.” Another student indicated, “I used mostly the computer and the laser disk, as I had used microscopes a lot in undergraduate school, so I had no trouble using them.” Students with limited microscope experience expressed that the microscope was to them an “excellent resource to use right before the test; initial learning is slow.” And to another, comparing the ease of computer-based resources to the microscope, the latter is “just too time-consuming and your slide might not have the structure.”
Virtual Microscope Table 1B presents ratings of the Virtual Microscope with respect to the same criteria. Resolution and quality of image were perceived as roughly comparable to those of the traditional microscope, but the ease of use was rated higher, as was overall educational value. A sample of student comments included the following: “Excellent tool.” “Excellent resource.” “The Virtual Microscope was an excellent resource for quizzing each other.” “Very time-efficient with actually quite good resolution. Very impressed with this.” Others noted that the technology of digitizing and matching imaged tissue regions is not perfect; that adding labels to a compilation of virtual images would be helpful (we are considering); and that the virtual imaging capability might be useful in class practical exams, as well as self-testing. Others correctly stated that for some specimens (e.g., ground bone preparation) the inability to through-focus with the VM was a detriment, but realized that the optimal use of the VM, like any
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TABLE 1. Human organ systems— histology laboratory resource evaluation data*
A. Rating the traditional microscope and glass slides with respect to Resolution and quality of the microscope image Ease of use Overall educational value B. Rating the virtual microscope on the Web with respect to Resolution and quality of the microscope image Ease of use Overall educational value C. Rating the general Histology Image Index on the Web with respect to Resolution and quality of the microscopic image Ease of use Overall educational value D. Rating the PLC videodisc (Histology: A Photographic Atlas) with respect to Resolution and quality of the microscopic image Ease of use Overall educational value
Min
Max
Avg
Count
SD
2
5
3.89
64
0.89
2 1
5 5
3.98 3.66
64 64
0.90 1.00
2
5
3.73
64
0.86
2 1
5 5
4.28 3.97
64 64
0.79 0.98
1
5
3.67
64
0.94
1 1
5 5
4.38 4.30
64 64
0.90 0.90
2
5
4.19
64
0.89
1 1
5 5
4.14 4.39
64 64
1.02 0.92
*Score key: 1, unacceptable; 2, poor; 3, fair; 4, good; 5, excellent.
other learning tool, is to recognize its limitations, and celebrate its many strengths. “Overall, a great learning tool.”
Web-Based Histology Images Table 1C shows data dealing with the collection of labeled photomicrographs of our student slide box specimens, termed the General Histology Image Index. This index is incorporated within the VM Histology Laboratory Web page and is easily accessed as a study resource. Again, resolution and quality of images were rated within the fair-to-good range, with ease of use and overall educational value rated higher, as good to excellent. Again, the range of responses hit both extremes. Sample student comments included the following: “Valuable resource! Much appreciated.” “Love it, just wished we could zoom in on the pictures.” “Great for starting out the histology study process.” “Very helpful—to look at the slides first with labels, then go to the microscope.” Engaging students in discussion concerning the wide range of responses seen in most categories of Ta-
bles 1A–C revealed not great dissatisfaction with a given resource, but a “what’s good for me” response from a student body highly diverse in its academic background, study habits, and learning behaviors. Providing a wide range of resources was seen as positive by those students who elected to partake of the available menu of resources, and in an order best suited to their particular learning styles.
ing both laser disc and other CD-ROM compilations of images included: “Excellent!!! The only problem here is that we need many more discs.” This is so great because you can see a hundred different examples of a structure in less than 10 minutes!“ ”Helpful review. I think people relied too much on it though.“ Faculty concurred that memorizing ”hundreds“ of images is neither a complete nor desirable end point in learning ”histology.“
Video Disc Atlas Table 1D reflects student enthusiasm for Web image catalogues, when they are well-labeled and carefully prepared with accompanying text. All categories received good to excellent ratings. Sample student comments concern-
Resource Utilization Table 2 addresses student perceptions of time spent using the various educational resources available to them. A bare 5 of 64 (8%) used the traditional light microscope as their primary study tool, and 10 of 64 (16%) used the VM
TABLE 2. Utilization of course resources by students At Which of the Following Did You Spend the Most Time? Traditional microscope and glass slides Virtual Microscope General Histology Image Index PLC videodisc (Histology: A Photographic Atlas)
Number of Times Chosen (of 64 Responses) 5 10 31 18
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this way. Thus nearly a quarter of the class used a microscope-based learning tool as their principal study tool. The other three quarters of the class emphasized study of labeled images on the Web, CD-ROMs, and laser discs. However, as a group, they succeeded in integrating static image study with microscopic study, as no one failed the final examination administered by using the traditional light microscope!
GRADUATE EDUCATION IN HISTOLOGY We suspect our readers recoiled not a little—as did we—at the pragmatic tone of many of the comments shared from our medical students who embraced those learning resources that were the easiest, fastest, and got the best results for them in the testing arena, with seemingly little consideration for intellectual curiosity, or lasting, concept-grounded learning! It is for just these reasons and sentiments that, at Iowa, we have for many years required weekly participation in (and given appropriate credit for) a supplemental Graduate Emphasis Seminar for graduate students enrolled in HOS/histology. These sessions are designed by the course director and students and take the varied form of advanced topic seminars, tutorials, or workshops. They invariably include student presentations of papers from the current literature relating molecular concepts with tissue and organ morphology. As underscored by Askew and Heffelfinger (1998), graduate education in histology for our future “new anatomists” must address the lack of perspective often exhibited by even our best graduate students who unfortunately enter graduate programs well-versed in the molecular but not the broader concepts of organization of cells and tissues. As these authors observe: “Most entrylevel graduate students are unable to decipher anatomical detail in tissue sections, and they are largely unaware of the research applications of histology (Askew and Heffelfinger, 1998).” We submit that each graduate program in anatomy and cell biology must assess how it best provides opportunities for its students to remedy this serious disciplinary information gap.
CONCLUSION Incorporation of the Virtual Microscope in the teaching of histology and histopathology is, in our experience, an important new learning modality, fully justified in being included as an important learning resource for any modern course in microscopic anatomy. It links ease of use and quality of image with ultimate accessibility for study at home or any electronic classroom within the College of Medicine and with many of the advantages of the traditional light microscope. These include the valued aspect of translating the image and thus gaining perspective of the whole microscopic specimen, not just a single microscopic field. Its capability of zoom magnification to study features or structures at various magnifications is also a distinct advantage over static
We have for many years required weekly participation in a supplemental seminar for graduate students enrolled in human organ systems/histology. image banks. It is amenable to individual as well as small-group study venues and to tutorial use with the teaching staff. Since its full inclusion in our list of teaching resources, faculty teaching time has been reduced by almost half. Staffing of each learning center, however, remains at one professor and one graduate teaching assistant each. Our contention is that, despite the wealth of real and virtual imaging capabilities available to students of histology, the most important resource to stimulating learning remains the one-on-one or small group interactions of students with faculty.
ACKNOWLEDGMENTS We thank our colleagues and medical administration for encouragement and support, and our students, for
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they are both the inspiration behind our efforts to improve the teaching of microscopic anatomy and histopathology, and our most valued critics. The authors gratefully acknowledge grant support from the National Library of Medicine (F.D., Principal Investigator) and the University of Iowa College of Medicine Educational Development Fund; the assistance in the preparation of the manuscript of Ms. Jean Gardner; and the technical assistance of Mr. Paul Reimann and his Anatomy/Cell Biology Departmental Biomedical Photography Support Team.
LITERATURE CITED Askew DS, Heffelfinger S. 1998. Graduate education in microscopic anatomy. Anat Rec (New Anat) 253:143–146. Bauer T, Metcalf NF, Metcalf WK, Prentice ED. 1976. Auto-instruction in histology and cell biology as a substitute for traditional laboratory activities. J Physiol 258:54P–55P. Cotter JR. 2001. Laboratory instruction in histology at the University at Buffalo: Recent replacement of microscope exercises with computer applications. Anat Rec (New Anat) 265:212–221 Downing SW. 1995. A multimedia-based histology laboratory course: Elimination of the traditional microscope laboratory (abstract). Medinfo 8:1695. Fitzharris TP. 1998. Survey of gross anatomy courses in the United States and Canada. Anat Rec (New Anat) 253:163– 166. Harris T, Leaven T, Heidger P, Kreiter C, Duncan J, Dick F. 2001. Comparison of a virtual microscope laboratory to a regular microscope laboratory for teaching histology. Anat Rec (New Anat) 265:10 – 14. Hightower JA, Boockfor FR, Blake CA, Millett CF. 1999. The standard medical microscopic anatomy courses: Histology circa 1998. Anat Rec (New Anat) 257:96 – 101. McMillan PJ. 2001. Exhibits facilitate histology laboratory instruction: Student evaluation of learning resources. Anat Rec (New Anat) 265:222–227. Ogilvie RW. 1995. An interactive histology image-barcode manual for a videodisc image library (abstract). Medinfo 8:1698. Trelease RB, Nieder Gl, Dorup J, Hansen MS. 2000. Going virtual with QuickTime VR: New methods and standardized tools for interactive dynamic visualization of anatomical structures. Anat Rec (New Anat) 261:64 –77.
