Validation of a Geant4 model of the X-ray fluorescence microprobe at the Australian Synchrotron.

A Geant4 Monte Carlo simulation of the X-ray fluorescence microprobe (XFM) end-station at the Australian Synchrotron has been developed. The simulation is required for optimization of the scan configuration and reconstruction algorithms. As part of the simulation process, a Gaussian beam model was developed. Experimental validation of this simulation has tested the efficacy for use of the low-energy physics models in Geant4 for this synchrotron-based technique. The observed spectral distributions calculated in the 384 pixel Maia detector, positioned in the standard back-scatter configuration, were compared with those obtained from experiments performed at three incident X-ray beam energies: 18.5, 11.0 and 6.8 keV. The reduced χ-squared (\chi^{2}_{\rm{red}}) was calculated for the scatter and fluorescence regions of the spectra and demonstrates that the simulations successfully reproduce the scatter distributions. Discrepancies were shown to occur in the multiple-scatter tail of the Compton continuum. The model was shown to be particularly sensitive to the impurities present in the beryllium window of the Maia detector and their concentrations were optimized to improve the \chi^{2}_{\rm{red}} parametrization in the low-energy fluorescence regions of the spectra.

Immersive virtual reality simulated learning environment versus role-play for empathic clinical communication training.

INTRODUCTION: The use of immersive virtual reality simulated learning environments (VR SLEs) for improving clinical communication can offer desirable qualities including repetition and determinism in a safe environment. The aim of this study was to establish whether the mode of delivery, VR SLE versus clinical role-play, could have a measurable effect on clinical empathic communication skills for MRI scenarios. METHODS: A split-cohort study was performed with trainee practitioners (n = 70) and qualified practitioners (n = 9). Participants were randomly assigned to four groups: clinician VR (CVR), clinician role-play (CRP), trainee VR (TVR), and trainee RP (TRP). Clinical communication skills were assessed using two methods: firstly, a self-reported measure - the SE-12 communication questionnaire and, secondly, a training and assessment tool developed by a panel of experts. RESULTS: Participants in the VR trainee (TVR) and clinician (CVR) groups reported 11% (P < 0.05) and 7.2% (P < 0.05) improvements in communication confidence post training, whereas trainees assigned to the role-play (TRP) intervention reported a 4.3% (P < 0.05) improvement. Empirical assessment of communication training scores assessing a participant's ability to select empathic statements showed the TVR group performed 5% better on average than their role-play counterparts (P < 0.05). CONCLUSION: The accuracy of participant's selection of appropriate empathic responses was shown to differ significantly following the training intervention designed to improve interactions with patients that present for an MRI scan. The results may demonstrate the capacity for immersion into an emotional narrative in a VR environment to increase the user's susceptibility for recalling and selecting empathic terminology.

Quantification of Student Radiographic Patient Positioning Using an Immersive Virtual Reality Simulation.

INTRODUCTION: Immersive virtual reality (VR) simulation environments facilitate novel ways for users to visualize anatomy and quantify performance relative to expert users. The ability of software to provide positional feedback before a practitioner progresses with subsequent stages of examinations has broad implications for primary and allied healthcare professionals, particularly with respect to health and safety (eg, exposing to x-rays). The effect of training student-radiographers (radiology technicians), with a VR simulation environment was quantitatively assessed. METHODS: Year 1 radiography students (N = 76) were randomly split into 2 cohorts, each of which were trained at performing the same tasks relating to optimal hand positioning for projection x-ray imaging; group 1 was trained using the CETSOL VR Clinic software, whereas group 2 was trained using conventional simulated role-play in a real clinical environment. All participants completed an examination 3 weeks after training. The examination required both posterior-anterior and oblique hand x-ray positioning tasks to be performed on a real patient model. The analysis of images from the examination enabled quantification of the students' performance. The results were contextualized through a comparison with 4 expert radiographers. RESULTS: Students in group 1 performed on average 36% (P < 0.001) better in relation to digit separation, 11% (P ≤ 0.001) better in terms of palm flatness and 23% (P < 0.05) better in terms of central ray positioning onto the third metacarpal. CONCLUSION: A significant difference in patient positioning was evident between the groups; the VR clinic cohort demonstrated improved patient positioning outcomes. The observed improvement is attributed to the inherent task deconstruction and variety of visualization mechanisms available in immersive VR environments.