Simulation of scattered radiation during intraoperative imaging in a virtual reality learning environment

X-ray scatter in projection radiography

Projection radiography is the most common radiological modality, and radiation safety of it concerns both radiation workers and the public. We measured and generated a series of scattered radiation maps for projection radiography and estimated effective doses of the supporting person during exposure. Measured adult patient protocols included chest posterior-anterior, chest lateral, pelvis anterior-posterior (AP), abdomen AP and bedside chest AP. Maps concretise spatial distribution and the scattered radiation dose rates in different imaging protocols. Highest and lowest rates were measured in abdomen AP and bedside chest AP protocols, respectively. The effective dose of supporting person in abdomen AP examination at distance of 0.5 m was 300 nSv and in bedside supine chest AP examination at distance of 0.7 m was 0.5 nSv. The estimated annual effective dose of emergency unit radiographer was 0.11 mSv. The obtained effective dose values are small compared to annual dose limits of radiation workers and the public.

Questionnaire survey of virtual reality experiences of digestive surgery at a rural academic institute: A pilot study for pre-surgical education

We developed a prototype VR platform, VECTORS L&M (VLM), aiming to enhance the understanding of digestive surgery for students, interns, and young surgeons by limiting costs. Its efficacy was assessed via questionnaires before implementation in surgical education. The VLM provides nine-minute VR views of surgeries, from both 180- and 360-degree angles. It was created with L.A.B. Co., Ltd. and incorporates surgery videos from biliary malignancy patients. Following VLM development, a survey was conducted among surgeons who had experienced it. Twenty-eight participants (32% of observers) responded to the survey. A majority (81%) reported positive experiences with the VR content and showed interest in VR video production, though some reported sickness. Most respondents were experienced surgeons, and nearly all believed VR was important for medical education with a mean score of 4.14 on a scale of up to 5. VR was preferred over 3D printed models due to its application versatility. Participants expressed the desire for future VR improvements, such as increased mobility, cloud connectivity, cost reduction, and better resolution. The VLM platform, coupled with this innovative teaching approach, offers experiential learning in intraabdominal surgery, effectively enriching the knowledge of students and surgeons ahead of surgical education and training.

Real-time mixed reality display of dual particle radiation detector data

Radiation source localization and characterization are challenging tasks that currently require complex analyses for interpretation. Mixed reality (MR) technologies are at the verge of wide scale adoption and can assist in the visualization of complex data. Herein, we demonstrate real-time visualization of gamma ray and neutron radiation detector data in MR using the Microsoft HoloLens 2 smart glasses, significantly reducing user interpretation burden. Radiation imaging systems typically use double-scatter events of gamma rays or fast neutrons to reconstruct the incidence directional information, thus enabling source localization. The calculated images and estimated 'hot spots' are then often displayed in 2D angular space projections on screens. By combining a state-of-the-art dual particle imaging system with HoloLens 2, we propose to display the data directly to the user via the head-mounted MR smart glasses, presenting the directional information as an overlay to the user's 3D visual experience. We describe an open source implementation using efficient data transfer, image calculation, and 3D engine. We thereby demonstrate for the first time a real-time user experience to display fast neutron or gamma ray images from various radioactive sources set around the detector. We also introduce an alternative source search mode for situations of low event rates using a neural network and simulation based training data to provide a fast estimation of the source's angular direction. Using MR for radiation detection provides a more intuitive perception of radioactivity and can be applied in routine radiation monitoring, education & training, emergency scenarios, or inspections.

The impact of 3D virtual reality radiography practice on student performance in clinical practice

INTRODUCTION

Simulation-based learning plays an integral role in preparing students for clinical practice. This study investigated the impact of immersive three-dimensional (3D) virtual reality (VR) simulation-based learning on first-year radiography students' performance in the clinical setting.

METHODS

A retrospective analysis of first-year radiography clinical assessments was carried out to compare performance pre-and post-introduction of VR. The stage one cohort with no VR education was considered the control group (n = 93). The VR group (n = 98) had seven hours of practice in the immersive VR suite (Virtual Medical Coaching). Experienced clinical tutors assessed first-year students performing an extremity radiographic examination in the clinical setting. Assessment criteria were ranked on a 5-point Likert scale from poor to excellent. Mann Whitney U Tests were applied to compare performance across cohorts.

RESULTS

Students trained with VR performed better across 20 of the 22 assessment criteria. VR-trained students performed significantly better (more ranked as 'very good' or 'excellent') than the control group in the following criteria; positioning patients for X-rays (19% difference) (U = 3525, z = -2.66, p < 0.05), selecting exposure factors (12% difference) (U = 3680, z = -3.13, p < 0.05), image appraisal of patient positioning (27% difference) (U = 3448, z = -2.9, p < 0.05) and image appraisal of image quality (18% difference) (U = 3514, z = -2.6, p < 0.05). Their comprehension of clinical indications, equipment set up and explanation of the procedure was also significantly better (p < 0.05).

CONCLUSION

This is the first study to investigate the translation of VR learning into radiography clinical practice. VR learning had a positive impact on the performance of first-year students in their clinical assessment, especially with respect to patient positioning, exposure parameter selection and image appraisal.

IMPLICATIONS FOR PRACTICE

VR is a valuable educational tool in preparing novice radiography students for clinical practice. It is particularly useful to enhance student knowledge in the areas of patient positioning, exposure factor selection and radiographic image appraisal.

Learning-based occupational x-ray scatter estimation

Objective. During x-ray-guided interventional procedures, the medical staff is exposed to scattered ionizing radiation caused by the patient. To increase the staff’s awareness of the invisible radiation and monitor dose online, computational scatter estimation methods are convenient. However, such methods are usually based on Monte Carlo (MC) simulations, which are inherently computationally expensive. Yet, in the interventional environment, immediate feedback to the personnel is desirable. Approach. In this work, we propose deep neural networks to mitigate the computational effort of MC simulations. Our learning-based models consider detailed models of the (outer) patient shape and (inner) anatomy, additional objects in the room, and the x-ray tube spectrum to cover imaging settings encountered in real interventional settings. We investigate two cases of scatter prediction. First, we employ network architectures to estimate the full three-dimensional (3D) scatter distribution. Second, we investigate the prediction of two-dimensional (2D) intensity projections that facilitate the intra-procedural visualization. Main results. Depending on the dimensionality of the estimated scatter distribution and the network architecture, the mean relative error of each network is in the range of 12% and 14% compared to MC simulations. However, 3D scatter distributions can be estimated within 60 ms and 2D distributions within 15 ms. Significance. Overall, our method is suitable to support the online assessment of scattered ionizing radiation in the interventional environment and can help to lower the occupational radiation risk.

Development and evaluation of the effectiveness of educational material for radiological protection that uses augmented reality and virtual reality to visualise the behaviour of scattered radiation

Understanding the behaviour of scattered radiation is important for learning appropriate radiation protection methods, but many existing visualisation systems for radiation require special devices, making it difficult to use them in education. The purpose of this study was to develop teaching material for radiation protection that can help visualise the scattered radiation with augmented reality (AR) and virtual reality (VR) on a web browser, develop a method for using it in education and examine its effectiveness. The distribution of radiation during radiography was calculated using Monte Carlo simulation, and teaching material was created. The material was used in a class for department of radiological technology students and its influence on motivation was evaluated using a questionnaire based on the evaluation model for teaching materials. In addition, text mining was used to evaluate impressions objectively. Educational material was developed that can be used in AR and VR for studying the behaviour of scattered radiation. The results of the questionnaire showed that the average value of each item was more than four on a five-point scale, indicating that the teaching material attracted the interest of users. Through text mining, it could be concluded that there was improved understanding of, and confidence in, radiation protection.

3D virtual reality simulation in radiography education: The students' experience

Introduction

Simulation forms a key element of undergraduate Radiography education as it enables students to develop their clinical skills in a safe environment. In this study, an immersive three-dimensional (3D) virtual radiography simulation tool was piloted in an undergraduate Radiography curriculum and user feedback retrieved.

Methods

The 3D virtual simulation tool by Virtual Medical Coaching Ltd was introduced to first year radiography students (n = 105). This technology guided students through a comprehensive process of learning anatomy, radiographic positioning and pathology. Students then X-rayed a virtual patient in the VR suite using HTC Vive Pro™ headsets and hand controllers. Instant feedback was provided. An online survey was later disseminated to students to gather user feedback. Thematic and descriptive statistical analyses were applied.

Results

A response rate of 79% (n = 83) was achieved. Most respondents (58%) reported enjoying VR simulation, whilst some felt indifferent towards it (27%). Ninety-four percent would recommend this tool to other students. The mean length of time it took for students to feel comfortable using the technology was 60 min (10–240 min). Most respondents (58%) desired more VR access. Students attributed enhanced confidence in the areas of beam collimation (75%), anatomical marker placement (63%), centring of the X-ray tube (64%) and exposure parameter selection (56%) to their VR practice. Many students (55%) advocated the use of VR in formative or low stakes assessments. Issues flagged included technical glitches, inability to palpate patient and lack of constructive feedback.

Conclusion

Student feedback indicates that 3D virtual radiography simulation is a valuable pedagogical tool in radiography education

Implications for practice

3D immersive VR simulation is perceived by radiography students to be a valuable learning resource. VR needs to be strategically implemented into curricula to maximise its benefits.