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Keywords:

  • computer;
  • education;
  • medical school;
  • histology;
  • microscope;
  • virtual microscopy

Abstract

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

During the interim between the 2003 and 2004 academic years, the cell and tissue biology and integrated medical neuroscience courses at the Medical College of Wisconsin made a complete and rapid switch from light microscopy- to virtual microscopy-based histology laboratories. This switch was prompted by the difficulties in maintaining and the cost of replacing the college's microscopes and microscope slides, and primarily by the desire to promote and streamline learning for our large classes (n > 200) of first-year medical students. A group of students who used the virtual microscope, another group of students who used the light microscope, and faculty with experience using both tools rated the effectiveness of the virtual microscope for learning and teaching. Also, to determine whether virtual microscopy affected student learning, laboratory examination scores for the 2004 class (n = 209) were compared with those of four previous classes that used light microscopes exclusively (n = 811). The switch from light microscopy to virtual microscopy was very favorably received by both students and faculty. More importantly, data from examination scores and course evaluation surveys indicated that use of the virtual microscope may significantly improve student performance and learning efficiency. Procedures for successfully implementing this change are described. Anat Rec (Part B: New Anat) 285B:19–25, 2005. © 2005 Wiley-Liss, Inc.


INTRODUCTION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

Virtual microscopy is an emerging technology for use in telepathology and histologic/pathologic education. Virtual microscopy image acquisition involves digitally photographing tissue sections on microscope slides using one or more microscope objectives at one or more focal planes. Using computer software, the large image files are tiled together, generating a composite image for viewing on computer monitors. In practice, students move the computer mouse to scan the digital specimen, mimicking scanning of the corresponding tissue section under a light microscope. Magnification and focus can be adjusted by clicking the mouse buttons.

Previous reports describe histology teaching programs that partly incorporated virtual microscopy while retaining light microscopy for selected aspects of the course (Heidger et al., 2002). Others made a gradual transition from light microscopy to virtual microscopy (Blake et al., 2003). At the Medical College of Wisconsin (MCW), we recently monitored the effect of adopting virtual microscopy in rapid and complete fashion for a large class of first-year medical students (n > 200). During the interim between the 2003 and 2004 academic years, the entire histology laboratory component of two first-year medical student (M1) courses—cell and tissue biology (CTB) and integrated medical neuroscience (neuro)—was changed from the exclusive use of light microscopy to the exclusive use of virtual microscopy.

The purpose of this study was to ascertain whether the complete and rapid switch from light microscopy to virtual microscopy affected student learning and faculty teaching. We hypothesized that the effects of this change would be positive. Results from surveys administered to students and faculty indicate that virtual microscopy was very favorably received. More importantly, data from examination scores and course evaluation surveys indicate that virtual microscopy may significantly improve learning efficiency and performance. Necessary steps for implementing this technology are described.

ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

WebSlide Production

MCW has a large collection of aging microscope slides for teaching histology that were generated in-house by histotechnologists. This collection is supplemented by a small number of commercially prepared specimens. More than 100 identical sets of teaching slides were loaned to pairs of students for use in histology laboratories. The slide sets were used annually between 1964 and 2003.

To generate a digital set of teaching slides, several microscope slides of each tissue in the teaching set were evaluated. One high-quality copy of each slide was selected for digitizing. More than 120 slides were sent to Bacus Laboratories (http://www.bacuslabs.com) for digitizing. The digital images were returned via hard disk drive to MCW, where they were transferred to the server hard drive. Bacus Laboratories provided WebSlide server software, which allowed individual images to be tiled together into a composite image.

Infrastructure/Network Specifications

A dedicated server computer was required to store the large images used by the virtual microscope. MCW purchased a server computer equipped with dual Xeon 2.8 GHz processors and 1.5 GB SDRAM. The server has five 36.4 GB 15 K rpm hard drives with hot swap spare and one 128 MB RAID controller to allow the hard drives to function together.

The MCW Computer Instruction Laboratory is equipped with 110 computer workstations running Windows XP using standard integrated video cards with 512 MB RAM. Half of the workstations have Pentium 4 processors and run at 2.4 GHz; the other half have Pentium 3 processors and run at 1 GHz. Active X software was downloaded onto each workstation. Software leased from Bacus Laboratories, called WebSlide Active X controller, automatically downloads onto each workstation from the server computer when students first access the virtual microscope.

Areas of the MCW network infrastructure (i.e., wiring connecting the server to the computer laboratory and eventually to the workstations) vary from 100 to 1,000 MB. The server has three network interface cards (NICs) at 1 Gig each and a 3 GB Input/Output capacity. The remaining connections have gigabyte capacity except the connection from the final wire closet to the desktop computers, which has 100 MB capacity.

Web Site Development

Dreamweaver MX Software (http://www.macromedia.com) with Active X controls and Visual Basic Script (http://www.microsoft.com) were used to design a Web site that allowed slides to be grouped by course and laboratory. This minimized the amount of scrolling required by students to find a slide of interest.

Surveys

First-year medical students (M1s) who used the virtual microscope for histology laboratories in the 2004 CTB and neuro courses were asked to complete a survey regarding its use. Second-year medical students (M2s) who had exclusively used the light microscope and glass slides for histology laboratories in the CTB and neuro courses were given directions for the virtual microscope and asked to complete a similar survey. Faculty who teach histology laboratories in the CTB and/or neuro courses were surveyed regarding the effectiveness of using the virtual microscope for teaching and in regard to their preference for its use in teaching versus the light microscope. In addition, data from surveys annually administered at the conclusion of M1 courses by the MCW Curriculum and Evaluation Committee were analyzed to evaluate learning efficiency. These instruments are described in Tables.

Analysis of Laboratory Examination Scores, Virtual Microscope Survey Data, and Course Evaluation Survey Data

Computer-based laboratory examination scores were compared by the Wilcoxon rigned-rank test. A general linear model was used to estimate least square means and confidence intervals. Survey results were presented as summarized group sizes and percentages. Survey results were compared by calculating odds ratios and confidence intervals using the chi-square or Fisher's exact tests for 2 × 2 tables. Statistical analyses were performed using SAS statistical software (http://www.sas.com) and StatXact software (http://www.cytel.com) by the MCW Biostatistics Consulting Service.

EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

To assess the educational impact of changing from light microscopy to virtual microscopy, mean laboratory examination scores of students who learned via virtual microscopy (2004) were compared with those of students who learned via the light microscope (2000–2003). During each year, four computer-based laboratory examinations were administered. We compared scores from examinations 2–4 only, because laboratory examination 1 involves electron microscopic rather than light microscopic images. For all years, laboratory examination format was the same; examination content was similar but not identical. Results in Table 1 show that the mean score on laboratory examinations 2 and 3 was similar whether students learned via virtual microscopy (2004) or light microscopy (2000–2003). However, for examination 4, the mean laboratory examination score of students who learned via virtual microscopy (2004) was significantly higher than that of students who learned via the light microscope (2000–2003).

Table 1. Comparison of examination scores: virtual vs. light microscopy*
 2000–2003 laboratory examination scores (X ± SD), light microscopy2004 laboratory examination scores (X ± SD), virtual microscopy
  • *

    As shown in the columns, two groups of scores are compared: those of students who learned via light microscopes and glass slides (years 2000–2003) and those of students who learned via the virtual microscope (2004).

  • a

    A statistically significant difference using the Wilcoxon signed-rank test (P < 0.0009).

Examination 287.76 ± 9.294 (n = 811)87.84 ± 8.861 (n = 209)
Examination 390.18 ± 8.349 (n = 811)90.69 ± 6.974 (n = 209)
Examination 493.53 ± 6.308 (n = 809)95.13a ± 5.155 (n = 208)

The ease of using the virtual microscope was assessed by surveying M1s (n = 206) upon completion of the CTB and neuro courses. Although this group had no MCW experience with light microscopes, most of the students (89.3%) had prior experience using light microscopes during the past year (n = 49; 23.8%) or the past 5 years (n = 135; 65.5%). One hundred percent of the M1 class responded to the survey. Responses regarding ease of using the virtual microscope are shown in Table 2.

Table 2. Students' responses to survey statements regarding ease of using the virtual microscope*
 Selecting a slide or changing from one slide to another is easy using the virtual microscopeScanning a slide is easy using the virtual microscopeChanging magnification is easy using the virtual microscopeAdjusting focus is easy using the virtual microscope
  • *

    The number of students responding in each category; percentages are shown in parentheses.

Strongly agree190 (92.2%)160 (77.7%)174 (84.5%)83 (40.3%)
Agree11 (5.3%)43 (20.9%)28 (13.6%)73 (34.4%)
Disagree1 (0.5%)0 (0%)2 (1.0%)45 (21.8%)
Strongly disagree3 (1.5%)0 (0%)0 (0%)2 (1.0%)
No response1 (0.5%)3 (1.5%)2 (1.0%)3 (1.5%)

Students were then asked to estimate subjectively the overall effectiveness of the virtual microscope for learning. As shown in Table 3, s overwhelmingly (98.5%) rated the effectiveness of the virtual microscope for learning as excellent or good.

Table 3. Results of M1 responses to the survey statement. “overall, I rate the effectiveness of the virtual microscope for learning as … ”
 NumberPercent
Excellent18690.3%
Good178.2%
Fair10.5%
Poor00.0%
No response21.0%
Total206100.0%

Because most students had prior experience using the light microscope, they were also asked to indicate their preferred learning mode. A large majority of M1 students (96.6%) agreed or strongly agreed with a statement indicating they preferred learning via the virtual microscope over the light microscope (Table 4).

Table 4. Results of M1 responses to the survey statement: “I prefer using the virtual microscope (over the student light microscope and glass slides) for learning histology for the CTB and neuro courses”
 NumberPercent
Strongly agree18991.8%
Agree104.8%
No preference21.0%
Disagree00.0%
Strongly disagree00.0%
No experience with LM41.9%
No response10.5%
Total206100.0%

The survey also included a space for personal student comments, revealing that M1s were essentially uniform in their strong enthusiasm for the virtual microscope. Their comments included adjectives such as “awesome,” “amazing,” “fantastic,” “easier,” and “convenient.” Comments that were particularly encouraging included the following: “[The virtual microscope] eliminated a lot of frustration I have had in the past with other microscopes… . Easier to ask questions and discuss slides with other people since we could all look at the same thing.” “The ease of use probably contributed to me studying slides more than I would have with conventional microscopy.” “This may have been the greatest transition/update one could possibly make.”

Given the very favorable response of M1s to the virtual microscope, we were interested in comparing their impressions with those of students who had used light microscopes and glass slides for histology laboratories in the CTB and neuro courses during the previous academic year (2003). All second-year medical students (M2s) were asked to become familiar with the virtual microscope at their convenience, then respond to the same survey statement (Table 5). M2s were given instructions on how to access the Web site and use the virtual microscope. Although they did not use the virtual microscope during their pathology course, some were familiar with Web-based virtual microscopy consequent to its having been referenced as optional material for two CTB laboratory sessions in 2003. Among 198 M2s who had taken the CTB course in 2003, 147 (74%) familiarized themselves with the virtual microscope and responded to the survey statement. In comparison with 96.6% of M1s who agreed or strongly agreed with the survey statement, 72.8% of M2s selected this response (Table 5).

Table 5. Results of M2 responses to the survey statement: “I prefer using the virtual microscope (over the student light microscope and glass slides) for learning histology for the CTB and neuro courses”
 NumberPercent
Strongly agree6644.9%
Agree4127.9%
No preference149.5%
Disagree138.8%
Strongly disagree21.4%
No experience with LM10.7%
No response106.8%
Total147100.0%

Whereas none of the M1 students disagreed or strongly disagreed with the statement “I prefer using the virtual microscope over the student light microscope and glass slides for learning histology for the CTB and neuro courses” (Table 4), 10.2% of the M2s expressed disagreement or strong disagreement (Table 5). Statistical analysis of the respective M1 and M2 student responses to this statement indicated that M1 students, who had course experience using the virtual microscope, exhibited a stronger preference for virtual microscopy compared to M2 students who became familiar with the virtual microscope but did not use it in their coursework (Table 6). Hence, while both M1s and M2s expressed a high degree of preference for virtual microscopy, those students having actual course experience with this teaching mode were significantly (P < 0.0001) more enthusiastic.

Table 6. Comparison of numbers of M1 and M2 students whose responses were positive or indifferent/negative to the statement: “I prefer using the virtual microscope (over the student light microscope and glass slides) for learning histology for the CTB and neuro courses”*
 M1 (used virtual microscopy in CTB and neuro)M2 (used light microscopy and glass slides in CTB and neuro)
  • *

    These data were grouped from the positive (strongly agree, disagree) and negative (no preference, disagree, strongly disagree) responses presented in Tables 4 and 5. Note that the other responses (no experience with LM, no response) were not included. A chi-square test performed on this 2 × 2 table revealed a statistically significant difference in the strength of preference between these two groups (P < 0.0001).

Strongly agree or agreen = 199n = 107
No preference, disagree, or strongly disagreen = 2n = 29

Although M2s had only a brief encounter with the virtual microscope, their written comments were mostly enthusiastic: “This program is phenomenal.” “I wish all histology could have been this clear when I took it.” “I'm jealous I didn't get it for CTB.” “I actually used the virtual scope when I did my board review histology.” However, some M2s expressed concern that M1s should obtain experience using the light microscope in order to be prepared for the microbiology course in the M2 year: “Using the actual light microscope in histo and neuro was key in order to be able to use it in micro lab, where the opportunity to learn about the microscope is not available.” Some M2s also expressed concern that use of the light microscope should be taught at some point in the curriculum: “Students are losing something by not actually using a microscope. Hopefully they will still feel comfortable with a microscope when they go into the clinics and need to look at wet preps, etc.”

Faculty involved in teaching histology laboratories in the CTB and neuro courses (n = 12) were also surveyed regarding their experience with the virtual microscope. All faculty had extensive previous experience using the light microscope for teaching the histological portion of these courses. When asked whether they prefer teaching with the light microscope or virtual microscope, nearly all indicated a strong preference for virtual microscopy (Table 7). The faculty member who disagreed explained, “I prefer the less sterilized view obtained with the microscope and glass slides because the experience reveals the difficulties that underlie the interpretation of images. I believe the struggle in their training makes them better doctors by challenging them to separate fact and artifact and more fully understand how much weight they can put on microscopic results when determining the diagnosis and recommending treatment.”

Table 7. Results of faculty responses to the survey statement: “I prefer using the virtual microscope (over student light microscopes and glass slides) for teaching histology for the CTB/neuro course”
 NumberPercent
Strongly agree1083.3%
Agree00.0%
No preference18.3%
Disagree18.3%
Strongly disagree00.0%
Total12100.0%

With the exception of that thought-provoking sentiment, all faculty comments were positive, expressing sentiments that virtual microscopy eliminated problems associated with light microscope-based teaching such as malfunction due to poor microscope maintenance, inability of students to master microscope skills, and variable slide quality. Faculty were also impressed that virtual microscopy reduced more substantive student frustrations. For example, a chronic problem in previous years was that most students did not complete the challenging light microscopic search-and-identify exercise on hematopoiesis despite having step-by-step written instructions that encourage interaction with faculty. By contrast, it was our impression that virtual microscope-based teaching of hematopoiesis (using identical instructions) enabled all students to complete this exercise within the allotted time of the laboratory session. Furthermore, when teaching hematopoiesis with the virtual microscope, students asked incisive mechanistic questions regarding differentiation of the various blood lineages. In addition, virtual microscopy diminished student frustration. For example, whereas previously the light microscope's focus and interocular distance required constant adjustment as faculty and/or members of the student laboratory group alternately viewed structures of interest, the virtual microscope enabled faculty and/or small groups of students to discuss structures of interest seen simultaneously on a single computer monitor. The faculty strongly believes that this is a distinct advantage of virtual microscopy that significantly increases teaching efficiency in the histology laboratory.

Although we were impressed that virtual microscopy improved faculty teaching efficiency, it was of paramount importance to ascertain whether this teaching mode affected student learning efficiency. We evaluated student responses to a query in the course evaluation survey annually administered upon completion of the cell and tissue biology course by the MCW Curriculum and Evaluation Committee. This question, analyzed here as one criterion of learning efficiency, asks students to indicate approximately how many total hours per week they spent studying for CTB. We compared responses to this question between students who learned histology via light microscopy (2003) versus students who learned histology via virtual microscopy (2004). As shown in Table 8, the number of students who spent less than 15 hr per week studying CTB in 2004 was significantly increased in comparison with 2003 student responses (P = 0.0002). This result indicates that the virtual microscope may improve student learning efficiency, reducing the number of hours per week that students spend studying cell and tissue biology.

Table 8. Student responses to the MCW Curriculum and Evaluation Committee CTB course evaluation survey question: “Approximately how many total hours per week did you study for this class (e.g., preparing for class, completing assignments, reading material)?”*
 2004 (used virtual microscopy in CTB)2003 (used light microscopy in CTB)
  • *

    Responses in two categories are compared: < 15 hr per week vs. > 15 hr per week. Frequencies of student response and percentages are listed for each category. A chi-square test performed on this 2 × 2 table revealed a statistically significant difference between the student responses in the different years (P = 0.0002).

<15 hr spent studying CTB per weekn = 160 (79.2%)n = 117 (61.9%)
>15 hr spent studying CTB per weekn = 42 (20.8%)n = 72 (38.1%)

DISCUSSION

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

The complete and rapid switch from light microscopy-based to virtual microscopy-based teaching in the histology portion of the Medical College of Wisconsin's cell and tissue biology and integrated medical neuroscience courses for first-year medical students invites several important questions, paramount among which is: Can virtual microscopy effectively replace light microscopy as a teaching and learning vehicle? Based on our combination of student and faculty impressions and, more concretely, on data from student and faculty questionnaires and student performance, we conclude that the virtual microscope can effectively replace the light microscope for teaching histology. For example, students who exclusively used virtual microscopy to learn histology (2004) were overwhelmingly positive about this teaching mode (Tables 2–4; although slightly less enthusiastic, students who had learned histology via light microscopy (2003) indicated a strong preference for virtual microscope-based learning (Tables 5 and 6). Faculty responses also indicated an overwhelming preference for teaching via the virtual microscope (Table 7). Moreover, use of the virtual microscope may streamline learning, as indicated by a decline in hours expended per week in study for the cell and tissue biology course (Table 8). Most importantly, the change to virtual microscopy clearly did not compromise student performance on histology laboratory examinations. In the instance of one laboratory examination, performance was improved as indicated by a significantly higher mean score (Table 1). Continued monitoring of student performance on histology examinations during subsequent years will indicate whether performance of the 2004 class indicates the onset of a statistically positive trend.

Consistent with our findings, previous studies have shown that light microscopy can be replaced by other instructional modes without diminishing student performance on laboratory examinations. As early as 1976, Bauer et al. reported that the use of Kodachrome slides with accompanying text and audio cassettes constituted “an effective substitute for a traditional histology laboratory.” More recently, Cotter (1997) described how computer-assisted instruction (not virtual microscopy) could replace microscope exercises in a medical histology course, reporting that computer-based learning was as effective as microscopes at improving the difference between students' pre- and postlaboratory quiz scores and sometimes improved student learning efficiency by reducing the average amount of time spent on some laboratory sessions. Prior to selecting the virtual microscope, we had evaluated Kodachrome slides, videotapes, and static computer images as supplements or replacements for microscope-based teaching. Each of these teaching modes was rejected because it eliminated the requirement for students to scan tissue preparations proactively in order to identify appropriate histological structures for study, a requirement we consider conducive toward gaining a full appreciation for histological complexity. The virtual microscope was selected because its use simulates the scan-and-find requirement of light microscope/slide-based learning. In this regard, it is worth emphasizing that as recently as 2001, Cotter reported that digitized computer images (not virtual microscopy) were inferior to teaching from images obtained using the light microscope. However, since that time, advances in virtual microscope technology, including the ability to focus and scan the entire slide, now more exactly simulate the light microscope experience. These advances enabled retention of the discovery-based format of traditional light microscope-based laboratory exercises; in fact, adapting the laboratory manual previously used for light microscope-based laboratories for use in virtual microscope laboratories required only minor revision.

The switch from light microscopy to virtual microscopy was favorably received by MCW faculty and students. The MCW class size (n > 200), which is well above the U.S. mean (X = 136) (Hightower et al., 1999), provides an opportunity to obtain statistically relevant assessments. Within this large sample, 98.5% of M1s rated the effectiveness of the virtual microscope for learning as excellent or good, while 96.6% of M1s agreed or strongly agreed that they preferred the virtual microscope over the light microscope/slides. While acknowledging the limitation that these sentiments were expressed by students who had not received a similar educational experience using the light microscope, this sentiment is overwhelmingly positive. The somewhat less enthusiastic response of M2 students to virtual microscopy may have resulted from their lack of a similar instructional experience with the virtual microscope.

We do not believe that such a positive outcome could have been achieved in the absence of adequate institutional infrastructure, which at MCW includes the availability of a computer instruction laboratory containing 110 workstations. In addition, MCW's infrastructure makes the virtual microscope highly accessible, inasmuch as the computer instruction laboratory is open 24/7, except during the 24-hr period prior to administration of computerized examinations. Even when the computer instruction laboratory is closed, students can access the virtual microscope Web site via 32 MCW library computers or from remote sites if these are equipped with a cable or DSL internet connection. In this regard, approximately 50% of MCW students indicated they have off-campus access to a computer equipped with a high-speed Internet connection, a percentage that will likely rise in the future. Additionally, MCW infrastructure enables students to exploit facilely the technological features of virtual microscopy, as indicated by 97% of M1s having agreed or strongly agreed that selecting and scanning slides, and changing magnification, was easy (Table 2); this outcome is attributed to the simplicity of the customized MCW Web site design, as well as to the technological competence of the students. Although only 74.4% of M1s agreed or strongly agreed that the virtual microscope was easy to focus (Table 2), this lower percentage was likely due to the slow loading time of the focusing window, a problem that should be ameliorated by installation of a new Cisco switch and increased bandwidth at the server level from 300 MB to 3 GB, and an upgrade of the ethernet cable from cat 5 to cat 6, which allows for giga-speed transfers.

Nearly all faculty who teach histology laboratories were enthusiastic about the switch from light to virtual microscopy (Table 7). Most felt the virtual microscope made teaching easier and more efficient. The most prominent advantage was deemed to be the virtual microscope's ability to enable small groups of faculty and students to view simultaneously structures of interest on the same computer monitor. This was in contrast to the time-consuming, inefficient practice of using a pointer in the light microscope ocular to identify remarkable structures, a process requiring each student to view individually the structure after making necessary adjustments to interocular distance and binocular focus.

The most significant issue raised in opposition to virtual microscopy-based learning was that of the MCW faculty member who expressed concern that its “less sterilized view” might compromise image interpretation. This concern is similar to that of Cotter (2001), who expressed concern that “students [using computer-aided instruction, not virtual microscopy] do not learn the thought processes and strategies that are used in analyzing real specimens.” We agree that students cannot learn to “read” a slide by viewing static images, computer or otherwise, based on our previous experience during which some of the light microscope-based exercises were replaced by static images in a program of computer-assisted instruction (CAI). Because faculty members were impressed that student learning was less than satisfactory using this modality, CAI was abandoned and the use of light microscopes was reinstituted. However, because virtual microscopy, with its ability to scan, change magnification, and focus on slide-based images is far superior to the passive examination of static images, we believe that the concern that students cannot learn to read slides is greatly reduced by the use of virtual microscopy.

Light microscopes are used at MCW in the microbiology course during the second year of the curriculum. In response to the concern expressed by some M2 students that M1s should learn to use the light microscope in the CTB course as preparation for the second-year microbiology course, or for any other course in the curriculum, such an objective is not part of the CTB course's teaching mission. Most (89.3%) of the M1 students indicated they had used a light microscope within the past 5 years. We anticipate that, resultant from their broad educational experience, students progressing to upper-division medical school courses, as well as to the clinical setting, should be able, when required, to acquire adequate expertise facilely and rapidly using the light microscope. While the attainment of light microscope skills might be desirable within an unconstrained medical school curriculum, we agree with Harris et al. (2001) that “the goal of microscopic anatomy and pathology education is to teach students normal and abnormal human structure, not how to use the microscope.”

Although our primary motivation for switching from light to virtual microscopy-based histology laboratories was the desire to facilitate and streamline student learning, an additional motivation for this change was the desire to eliminate the expense and difficulty of maintaining a collection of high-quality glass microscope slides for teaching 200+ students. Commercially available slides that we examined were of low quality. Although slides produced in-house by the MCW pathology service were high quality, it was neither feasible nor within the mission of this clinical enterprise to accommodate such educational needs, especially since more than 100 copies of each slide were required. Moreover, the requirement of the laboratory director and office staff to monitor student use and abuse of slide sets was bothersome, a situation that likely generated student comments on course evaluations indicating they were hesitant to use microscope slides for fear of breaking them and incurring replacement costs. In contrast with these problems, a clear advantage of virtual microscopy is an ability to maintain, expand, and update the digital slide set, for which purpose only a single high-quality microscope slide is required. Also, the annual lease agreement with Bacus Laboratories allows us to access slide collections from other subscribing institutions.

A related cost-saving advantage of virtual microscopy is that light microscopes no longer must be purchased or maintained. Traditionally, MCW has loaned more than 400 light microscopes to its students free of charge. This microscope collection, comprised of various manufacturers, is 17–26 years old. Despite maintenance provided by MCW personnel and outside repair services, many of the microscopes have exhausted their usefulness, causing understandable complaints from frustrated student users. We shunned the prospect of requiring groups of students to share microscopes due to high replacement cost (≤ $1,500 × 400 students = $600,000). Considering these issues, virtual microscopy has provided a very cost-effective alternative, especially since MCW was already equipped with appropriate network infrastructure and a state-of-the art computer instruction laboratory. Histology teachers wanting to incorporate virtual microscopy at cost savings may wish to investigate free virtual microscopy resources (Harris et al., 2001). However, appropriate infrastructure at both the origination and destination institutions must be established prior to using any virtual microscope technology. Although we have not compared the educational impact of the virtual microscopy system used at MCW versus any other virtual microscopy system, our experience suggests that a positive educational impact requires a virtual microscopy system having the following features: ability to scan an entire slide; ability to focus on a slide; availability of high magnification (e.g., up to 60× for blood and bone marrow); precise alignment of individual images to form a composite image; and ability to present specific slides (e.g., from the institution's collection) in an institution-specific format (e.g., institution-designed Web site).

In conclusion, we have found that, for the purpose of teaching and learning histology at the level of first-year medical students, virtual microscopy is a highly effective and popular substitute for light microscopes and glass slides. The virtual microscope offers the advantages of reduced cost and maintenance while retaining the positive features of light microscope-based instruction. Although data to be acquired during subsequent years will be required to verify the initial observations reported here, learning via virtual microscopy may significantly improve learning efficiency as well as student performance.

Acknowledgements

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED

Supported by grants from the MCW Learning Resources Fund (to J.L.). The encouragement and support of Dr. Joseph C. Besharse and Mr. Brent E. Seifert are gratefully acknowledged.

LITERATURE CITED

  1. Top of page
  2. Abstract
  3. INTRODUCTION
  4. ESTABLISHING AND ASSESSING VIRTUAL MICROSCOPE TECHNOLOGY
  5. EDUCATIONAL IMPACT OF VIRTUAL MICROSCOPY
  6. DISCUSSION
  7. Acknowledgements
  8. LITERATURE CITED