Chiropractic Student Perspectives on The Use of Virtual Radiography Simulation An Observational Study Reporting on Chiropractic Students’ Perception on The Use of Virtual Radiography as A Clinical Learning Tool

Background Virtual radiography provides students with an opportunity to practise their clinical skills in patient positioning and evaluating radiographic images. The purpose of this pilot study was to introduce Projection VR™, a software radiography simulation program, into a student chiropractic program and evaluate its potential application as a teaching and learning tool. Methods Undergraduate chiropractic students, enrolled in a radiographic course (unit within the chiropractic program), were invited to attend a scheduled laboratory where they were introduced to, and undertook purposefully designed activities using the radiography simulation. At the end of this activity, students were asked to complete an online survey to describe their perceptions of the educational value of the software program. Descriptive and inferential statistics were used to evaluate outcomes. Results Responses were received from 44 out of the 47 students who attended the scheduled laboratory (response rate 92%). Overall students were positive about this simulation identifying that it was easy to use (95%) and that they could control the equipment as needed (95%). The main reported benets included students being enabled to repeat tasks until they were satised with the results (98%) and being able to quickly assess images and determine if changes needed to be made (98%). Participants reported improvement in their understanding of the effect of exposure factors on patient radiation dose (93%) as well as their technical image evaluation (84%) and problem-solving skills (80%). Conclusions The results of this study suggest that virtual radiography is a valuable complementary resource in providing chiropractic students with radiographic knowledge and skills.


Background
Radiography has been integrated into chiropractic teaching programs since 1910 when B.J. Palmer purchased an x-ray unit for the Palmer School of Chiropractic in Davenport, Iowa [1]. It has been used as a diagnostic tool in the biomechanical evaluation of the spine and pelvis and to help identify contraindications to manual therapy.
It continues to be taught as a core course in all chiropractic programs in Australia and most chiropractic programs throughout the world [2][3][4].
Maintaining the quality of imaging whilst minimising the radiation dose to patients is a priority which is highlighted by the Australian Radiation Protection and Nuclear Safety Agency [5] and one which is emphasised in clinical radiographic training and radiology courses (MEDS2144 Introduction to Diagnostic Imaging, MEDS2143 Advanced Diagnostic Imaging and REHA2203 Chiropractic 6 Theory) at RMIT University [6].
The opportunity to participate in simulated radiography is complementary to rigorous training in the theoretical and clinical aspects of plain lm diagnostic imaging.
In recent years, computer-based simulation radiography has been introduced in undergraduate radiography programs with promising results [7,8] .However, its usefulness in achieving clinical learning outcomes in pre-clinical undergraduate chiropractic programs has not been previously evaluated.
This study aimed to introduce a software radiography simulation tool called Projection VR™ into a chiropractic, pre-clinical undergraduate setting and gather student feedback about its application as a clinical learning tool and strategy.

Methods
The Human Research Ethics Committee of the Royal Melbourne Institute of Technology (RMIT) University (BSEHAPP 06-15) approved the project, including its design and recruitment methods.

Participants:
Chiropractic students in the second semester of year four of the program in 2016 were recruited as part of their traditional practical sessions in radiography. Informed consent was obtained in the rst test item of an online survey, with respondents able to exit at this point if they so preferred.

Procedure:
Participating chiropractic students were scheduled to attend one laboratory session which used the computer-based virtual radiography simulation software Projection VR™. Projection VR™ simulation in this university setting could be adequately delivered via Windows 8 or 7 (64 or 32 bit) with a graphics processor of at least DirectX and Shader Model 3.0 or 4.0 hardware support and 512 megabytes or more of dedicated video RAM. The standard computer laboratory equipment at the university met or exceeded these requirements.
A worksheet on simulated radiography of the lumbar spine was developed for chiropractic students using Projection VR™. No training was conducted prior to using the simulated radiography system as students learned to use the technology while they undertook the activity under the guidance of an experienced lecturer in radiography. The detailed worksheet allowed the students to use the technology as they undertook the laboratory activity. Each student used the simulation individually.
There were three key areas of focus for this activity. Firstly, for each student to simulate patient positioning and technical set up in preparation for taking the Anterior to Posterior lumbopelvic image and to generate an AP lumbopelvic (APLP) image ( Figure 1).
Secondly, having produced an unrotated APLP, students were then asked to rotate their patient so that the patient's right posterior side was closer to the image receptor ( Figure 2). Before generating the image, students were asked what distinguishing anatomical features they expected to see on the image ( Figure 2). This strategy was used to support active and engage critical thinking as students consciously paused and re ected before they undertook their next action [9]. Thirdly, the effect of exposure factor selection on the digital image as well as patient dose was investigated. This was tested using two methods, namely application of the 15% rule and the effect of decreasing and increasing milliamp seconds (mAs) on digital images. Increasing kilo volt peak (kVp) with a concomitant decrease in mAs is expressed as the 15% kVp rule. The 15% rule states that a 15% increase in kVp is the equivalent of doubling the exposure received at the image receptor [10,11]. To maintain exposure at the image receptor, the mAs is halved. The increase in kVp, when applying the 15% rule, is variable and dependent on the original kVp. For example, at 60 kVp, the calculated change in kVp is be 9 kVp whereas at 80 kVp, the required change is 12 kVp. Studies examining application of the 15% kVp rule demonstrate a considerable reduction in patient dose (22% -60%) without adversely affecting image quality [12,13]. This is an important nding as increasing kVp reduces subject contrast and could therefore potentially negatively impact image quality [10,11] . Before generating the image acquired using the 15% rule, students were asked what change if any they may expect to see on the image ( Figure 3) and what impact, if any, applying the 15% rule would have on patient dose. Technical data available in Projection VR™ relating to radiation dose for the two images generated is provided in Figure 4. Entrance surface dose (ESD) measurements were compared for the two exposure techniques. The nal aspect of selection of exposure factors on digital images was undertaken by asking students what difference they would expect to see on the radiographic image and on patient dose if they were to half or double the mAs. Generated images are provided in Figure 5.
Throughout the session, students were asked to predict the outcome of each change in patient position or exposure factors before they generated and saw images or technical data. This method was used to encourage students to think critically in applying their decision-making skills in a clinical setting and has been found to reinforce learning by other authors [9,14,15] .

Evaluation of virtual radiography
Students who were enrolled in the radiographic positioning course in the chiropractic program were invited to participate anonymously in an online Qualtrics survey during the session. The survey comprised a mix of quantitative and qualitative items including Likert scales and open-ended questions. This assessed the ease with which students used Projection VR™ and the extent to which they developed program skills. Survey data were then entered for analysis.
Data Analysis: The survey data were entered into SPSS 21.0® and descriptive and inferential statistics were used for analysis. Cross tabulations were performed using age group and gender and self-reported con dence using computer technology to determine if relationships existed. Differences between groups were examined using chi-square analysis and Fisher's exact test.
Analysis of survey data was descriptive only as this research involved an exploratory snap-shot process -that is, the survey was only administered once [16] .

Results
Responses were received from 44 out of 47 participants in the practical sessions. The gender and age characteristics of the responding students are presented in Table 1.  (16) The majority of students were female (68%) (M = 14, F = 30). All age groups were represented in this sample and included both high school leavers and mature aged students.

Technology
Given that Projection VR™ involves computer-based simulation, participants were asked about their con dence in using this technology as part of their learning strategy. Eighty-two% (n = 36) of responding participants described themselves as con dent or moderately con dent in the use of computer technology. Only 18% (eight students) reported that they had previous experience using computer-based simulation. No relationship was shown to exist (p > .05) between gender or age and students' perception of their con dence in the use of computer technology.
Students' perceptions of ease of use of Projection VR™ are summarised in Table 2. Overall, students were positive regarding ease of use of the simulation software and their ability to control the equipment during the learning activity. Some students commented that the simulation could be improved by making it easier to use, with one student specifying "some of the keys made it hard to set up accurately".
Chiropractic students' perceptions of use of Projection VR™ as a learning tool for radiography is displayed in Table 3. Students generally perceived Projection VR™ as a worthwhile educational tool that quickly generated radiographic images and enabled them to re ne the process until they were con dent in its application. Student comments described bene ts of using the simulation including "Easy and quick visualisation of an x-ray image", "It was a good simulation to be able to see what we're actually imaging" and "you can visualise anything you want to, at whatever angle you want to. Very helpful especially for visual learners like myself".
Students also reported that using the program encouraged them to think more about radiographic technique and it facilitated their problem-solving skills. Student comments included "made me think about what I was doing", "helped me to think wisely on how the image should be produced" and "enabled me to produce images and see where I needed to correct myself to get a better image".
In addition, students identi ed that the simulation activity enhanced their understanding of technical factor selection and radiation dose. For example, students stated that using the simulation "helped me to understand the exposure", "helped me understand the technical side, not just positioning" and it "gave us extra information on patient dose and levels of radiation".
Students also perceived the use of this simulation program as enhancing their learning opportunities. Their comments included "it combines the theory and practical context taught during Chiropractic Theory 6 whilst introducing a new way of expanding our skills and knowledge through technology" and "regular practice sessions with the computers would be great to assist the physical learning". Students also recognised that this simulation provided a safe learning environment as it did not require the use of radiation "being able to redo and correct any mistakes without worry".
Students did report limitations of the simulation including that, as movement of x-ray tube was controlled by computer keys, "some buttons are di cult to nd" and "some of the keys made it hard to set up accurately". It was also noted that as you are unable to palpate the virtual patient "more bony landmarks on patient" were needed.

Discussion
The aim of this study was to explore chiropractic students' perceptions of the Projection VR TM to assist in developing their radiographic skills and con dence in a laboratory setting. This study suggested that the simulation did improve students' learning experience.
The Projection VR™ was previously incorporated into the Medical Imaging program in the School of Health and Biomedical Sciences (SHBS) at RMIT University with most technical complications being resolved by the time the simulation program was trialled with chiropractic students. In general, the program supported students' skill development and enhanced con dence levels. Moreover, gender and age have been reported as possible barriers to using computer technology. In this study, differences in con dence levels were not associated with gender and age.
Another potential application of this program is remote access by students. The advantages of such access include the exible delivery of learning and teaching, overcoming geographical barriers in terms of travel as well as students being able to acquire skills and knowledge at their own pace [17].
Students in this study identi ed that remote access to this simulation would be a bene cial change e.g. "simulation of practicals into computers makes practice easier and more accessible", "make it readily available to practise at home" and "use of it at home via RMIT website, lists of views required for exam so we can practice".
Given that there is variety in the reported levels of con dence, computer skills and abilities among students, the option of their being able to progress through simulation activities at their own pace is likely to facilitate the learning experience.

Con dence and skill development
In general, the introduction of Projection VR™ increased students' con dence in patient positioning procedures and their ability to evaluate radiographic images. It has been reported that enhancing students' clinical radiographic skills as they make the transition from their pre-clinical undergraduate education to clinical practice may help to alleviate the stress associated with this transition [18].
Having acquired the skills to con dently set up radiographic procedures and evaluate images, students have reported being able to better focus their energies on re ning their communication and patient-interaction skills [19].
Students also described that participating in the Projection VR™ simulation positively in uenced their ability to problem solve.
These ndings are consistent with other published reports that highlight the value of students critically re ecting on their perceived strengths and weaknesses as a step to solving future clinical challenges and contributing to a range of other important clinical and professional standards [20,21].
Ninety-three percent of students identi ed that the simulation activity enhanced their understanding of the effect of changing radiographic exposure factors on patient dose. Chiropractors who perform radiography have a responsibility to select exposure parameters which minimise patient dose when producing clinically diagnostic images. Key parameters that a chiropractor controls and can manipulate for radiographic examinations include tube voltage (kVp), tube current and time (mAs) and source to image distance (SID). If SID is traditionally xed at 150 cm for chiropractic planar imaging [22], then student chiropractors should develop a good understanding of 15% rule as a radiation dose reduction strategy. Projection VR™ simulation provides similar percent dose reduction measurements to direct dosimetry measurements when assessing application of the 15% rule [23]. Student comments also highlighted the value of using this simulation to better understand technical factor selection for planar radiography "It helped me learn more about the technical side of medical imaging, such as kVp and dosages" and "gave us extra information on patient dose". Projection VR™ is a useful educational tool to support student learning focussed on exposure parameters and dose reduction technique in planar radiography. Potential applications of the simulation program within the chiropractic curriculum may include: a) assist in providing a blended learning approach to teaching radiographic positioning that includes the theoretical basis of radiography in chiropractic practice, face-to-face practicals and virtual radiography to complement and reinforce these more traditional approaches to teaching and learning; b) help students to better understand how positioning in uences radiation exposure (including factors such as skin dose and absorbed dose); c) provide a cost-effective and e cient mechanism to 'practice' positioning; d) assist in demonstrating how positioning in uences radiographic anatomy; e) currently none of the four chiropractic programs in Australia incorporate virtual radiography in their curricula and the preliminary ndings of this study demonstrate the potential to incorporate virtual chiropractic radiography into their curricula as part of an effective blended learning approach to learning and teaching.

Study limitations
This study explored the students' perceptions of virtual radiography in the undergraduate pre-clinical radiography course as part of a university chiropractic program.
Previous authors have noted that student performance may be in uenced by a variety of factors [7,19] and this interplay of factors may confound the ability to independently evaluate the role of speci c potential enablers such as simulated teaching. This is particularly true when an innovative teaching tool or strategy is introduced into a new learning environment [19].
Documenting the student usage patterns of innovative teaching programs such as simulated radiography may also provide valuable information about how to best achieve exibly delivered, clinical educational programs such as this in the future.

Conclusion
The Projection VR™ software was adapted for use in an undergraduate university chiropractic radiography program.
The introduction of this software was associated with multiple bene ts including an increase in skills and con dence in students' ability to effectively prepare their patients for radiographic positioning and quality imaging while minimising their exposure to irradiation dose.
The software also promoted their problem-solving skills in preparation for their transition to professional practice.   Technical data display available when using Projection VR™ allowing for comparison of Entrance Surface Dose (ESD) with 15% rule applied. Image on right 81 kVp, 40 mAs and image on left 93 kVp, 20 mAs.