Visualization of stereoscopic anatomic models of the paranasal sinuses and cervical vertebrae from the surgical and procedural perspective

Resident Training in Spine Surgery: A Systematic Review of Simulation-Based Educational Models

OBJECTIVE

With the increasing prevalence of spine surgery, ensuring effective resident training is becoming of increasing importance. Training safe, competent surgeons relies heavily on effective teaching of surgical indications and adequate practice to achieve a minimum level of technical proficiency before independent practice. American Council of Graduate Medical Education work-hour restrictions have complicated the latter, forcing programs to identify novel methods of surgical resident training. Simulation-based training is one such method that can be used to complement traditional training. The present review aims to evaluate the educational success of simulation-based models in the spine surgical training of residents.

METHODS

Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, the PubMed, Web of Science, and Google Scholar databases were systematically screened for English full-text studies examining simulation-based spine training curricula. Studies were categorized based on simulation model class, including animal-cadaveric, human-cadaveric, physical/3-dimensional, and computer-based/virtual reality. Outcomes studied included participant feedback regarding the simulator and competency metrics used to evaluate participant performance.

RESULTS

Seventy-two studies were identified. Simulators displayed high face validity and were useful for spine surgery training. Objective measures used to evaluate procedural performance included implant placement evaluation, procedural time, and technical skill assessment, with numerous simulators demonstrating a learning effect.

CONCLUSIONS

While simulation-based educational models are one potential means of training residents to perform spine surgery, traditional in-person operating room training remains pivotal. To establish the efficacy of simulators, future research should focus on improving study quality by leveraging longitudinal study designs and correlating simulation-based training with clinical outcome measures.

Creating Virtual Models and 3D Movies Using DemoMaker for Anatomical Education

Three-dimensional (3D) anatomy models have been used for education in health professional schools globally. Virtual technology has become more popular for online teaching since the COVID-19 pandemic. This chapter will describe a project in which a series of virtual anatomical models of organs and structures were developed for educational purposes, and it will describe in detail how to build three-dimensional (3D) movies using DemoMaker. Although setting up the 3D system was complicated and challenging, the process of reconstructing 3D models from radiographic images and the steps of creating animations and 3D movies are exponentially simpler. These efforts require minimal training, thus allowing most people to be able to engage in this modeling process and utilize the moviemaking steps. Amira® software and computed tomographic angiography (CTA) data were used to create 3D models of the lungs, heart, liver, stomach, kidney, etc. The anatomical locations of these structures within the body can be identified and visualized by recording information from multiple CTA slices using volume and surface segmentation. Ultimately, these virtual 3D models can be displayed via dual projectors onto a specialized silver screen and visualized stereoscopically by viewers as long as they wear 3D polarized glasses. Once these 3D movies are created, they can be played automatically on a computer screen, silver screen, 3D system playback screen, and video player, and they can be embedded into PowerPoint lecture slides. Both virtual models and movies are suitable for self-directed learning, face-to-face class teaching, and virtual anatomy education. Model animations and 3D movie displays offer students the opportunities to learn about anatomy and the anatomical positions of organs in the body and their 3D relationships to one another. By observing and studying these 3D models, students have the potential to be able to compartmentalize the anatomical information and retain it at a higher level than students learning corresponding anatomy without similar resources.

Learning in Stereo: The Relationship Between Spatial Ability and 3D Digital Anatomy Models

Three-dimensional (3D) digital anatomical models show potential to demonstrate complex anatomical relationships; however, the literature is inconsistent as to whether they are effective in improving the anatomy performance, particularly for students with low spatial visualization ability (Vz). This study investigated the educational effectiveness of a 3D stereoscopic model of the pelvis, and the relationship between learning with 3D models and Vz. It was hypothesized that participants learning with a 3D pelvis model would outperform participants learning with a two-dimensional (2D) visualization or cadaveric specimen on a spatial anatomy test, particularly when comparing those with low Vz. Participants (n = 64) were stratified into three experimental groups, who each attended a learning session with either a 3D stereoscopic model (n = 21), 2D visualization (n = 21), or cadaveric specimen (n = 22) of the pelvis. Medical and pre-medical student participants completed a multiple-choice pre-test and post-test during their respective learning session, and a long-term retention (LTR) test 2 months later. Results showed no difference in anatomy test improvement or LTR performance between the experimental groups. A simple linear regression analysis showed that within the 3D group, participants with high Vz tended to retain more than those with low Vz on the LTR test (R²  = 0.31, P = 0.01). The low Vz participants may be cognitively overloaded by the complex spatial cues from the 3D stereoscopic model. Results of this study should inform resource selection and curriculum design for health professional students, with attention to the impact of Vz on learning.

Virtual Reality in Medical Students' Education: Scoping Review

BACKGROUND

Virtual reality (VR) produces a virtual manifestation of the real world and has been shown to be useful as a digital education modality. As VR encompasses different modalities, tools, and applications, there is a need to explore how VR has been used in medical education.

OBJECTIVE

The objective of this scoping review is to map existing research on the use of VR in undergraduate medical education and to identify areas of future research.

METHODS

We performed a search of 4 bibliographic databases in December 2020. Data were extracted using a standardized data extraction form. The study was conducted according to the Joanna Briggs Institute methodology for scoping reviews and reported in line with the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews) guidelines.

RESULTS

Of the 114 included studies, 69 (60.5%) reported the use of commercially available surgical VR simulators. Other VR modalities included 3D models (15/114, 13.2%) and virtual worlds (20/114, 17.5%), which were mainly used for anatomy education. Most of the VR modalities included were semi-immersive (68/114, 59.6%) and were of high interactivity (79/114, 69.3%). There is limited evidence on the use of more novel VR modalities, such as mobile VR and virtual dissection tables (8/114, 7%), as well as the use of VR for nonsurgical and nonpsychomotor skills training (20/114, 17.5%) or in a group setting (16/114, 14%). Only 2.6% (3/114) of the studies reported the use of conceptual frameworks or theories in the design of VR.

CONCLUSIONS

Despite the extensive research available on VR in medical education, there continue to be important gaps in the evidence. Future studies should explore the use of VR for the development of nonpsychomotor skills and in areas other than surgery and anatomy.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

RR2-10.1136/bmjopen-2020-046986.

Combination of volume-rendering 3D surface modeling and medical illustration to capture the living fetus

OBJECTIVE

A good medical illustration renders essential aspects of a procedure or condition faithfully, yet idealizes it enough to make it widely applicable. Unfortunately, the live fetus is generally hidden from sight, and illustrating it relies either on autopsy material or manipulated newborn images. High-definition volume rendering of diagnostic imaging data can represent hidden conditions with an almost lifelike realism but is limited by the resolution and artifacts of the data capture. We have combined both approaches to enhance the accuracy and didactic value of illustrations of fetal conditions.

METHODS

Three examples, of increasing complexity, are presented to demonstrate the creation of medical illustrations of the fetus based on semiautomatic computerized posthoc manipulation of diagnostic images.

RESULTS

The end product utilizes the diagnostic accuracy of ultrasound and magnetic resonance imaging of the fetuses and the spatial manipulation of 3D models to create a lifelike, accurate and informative image of the fetal anomalies.

CONCLUSION

Volume-rendering and 3D surface modeling can be combined with medical illustration to create realistic and informative images of the developing fetus, using a level of detail that is tailored to the intended audience.

Comparison of Magnetic Resonance Angiography and Computed Tomography Angiography Stereoscopic Cerebral Vascular Models

In this paper, we will discuss and compare the stereoscopic models developed from two types of radiographic data, Magnetic Resonance Angiography (MRA) images and Computed Tomography Angiography (CTA) images. Stereoscopic models were created using surface or volume segmentation and semi-auto combined segmentation techniques. Although, the CTA data were found to improve the speed and quality of constructing virtual vascular models compared to conventional CT data, small blood vessels were difficult to capture during the imaging and reconstruction process thereby limiting the fidelity of the stereoscopic models. Thus, high contrast Magnetic Resonance Angiography (MRA) images offer better resolution to visualize and capture the smaller branches of the cerebral vasculature than CTA images.

Use Stereoscopic Model in Interventional and Surgical Procedures

The 3-dimensional (3D) stereoscopic modeling software allows anatomists to create high-resolution 3D models from computed tomography (CT) images. In this paper, we used high resolution CT images from a cadaver and a patient to develop clinically relevant anatomic models that can be used to teach surgical trainees different surgical procedures and approaches. The model facilitates visualization, manipulation, and interaction. It can be presented in stereoscopic 3D in a virtual environment, either in a classroom setting or immediately preceding a surgical procedure.

Anatomy Visualizations Using Stereopsis: Current Methodologies in Developing Stereoscopic Virtual Models in Anatomical Education

Technology for developing three-dimensional (3D) virtual models in anatomical sciences education has seen a great improvement in recent years. Various data used for creating stereoscopic virtual models have also been constantly improving. This paper focuses specifically on the methodologies of creating stereoscopic virtual models and the techniques and materials used in developing stereoscopic virtual models from both our previous studies and other published literature. The presentation and visualization of stereoscopic models are highlighted, and the benefits and limitations of stereoscopic models are discussed. The practice of making 3D measurements on the lengths, angles, and volumes of models can potentially be used to help predict typical measurement parameters of anatomical structures and for the placement of surgical instruments. Once stereoscopic virtual models have been constructed, their visualization and presentation can be implemented in anatomy education and clinical surgical trainings.

NASAL INTERNAL AND EXTERNAL AERODYNAMICS FOR HEALTHY AND BLOCKED CAVITIES

Human nasal airflow in a healthy and partially blocked cavities is investigated using computational and experimental means. While previous studies focused on the flow inside the nasal cavity, this study also looks at the external air stream coming out of the nostrils. The aim is to investigate the airflow subject to partial blocking in the nasal cavity and assess the potential of using a flow visualization method to identify abnormal nasal geometry. Two methods of study are used: Computational Fluid Dynamics (CFD) and experiment based on Particle Image Velocimetry (PIV). Nasal cavity geometry is reconstructed from CT scans. The flow visualization Schileren method is also demonstrated. The computational results agree well with the previous results in terms of Nasal Resistance (NR) and character of the internal flow. Good agreement is also found in the external aerodynamics during expiration between the computational and experimental results. Several generic partial blockages are investigated to show changes in NR, turbulence energy and the air stream leaving the nostrils during expiration. Anterior blockages are found to have more profound effects on all these three aspects, but all show effects on the external air stream. A possible universal angle for the external air stream emitted by a healthy nasal cavity is discussed.

Three-Dimensional Printed Skull Base Simulation for Transnasal Endoscopic Surgical Training

OBJECTIVE

Transnasal endoscopic skull base surgery (SBS) presents a major challenge for inexperienced neurosurgeons because of the complicated anatomic structures, 2-dimensional endoscopic view, limited operative field, and required skills. We designed a personalized multimaterial and multicolor three-dimensional (3D)-printed SBS simulation to reproduce the complex anatomy of the skull base. The fidelity and feasibility for anatomic education and surgical training were assessed.

METHODS

Two-dimensional computer tomography and magnetic resonance images were collected from a 42-year-old healthy male volunteer. After 3D modeling and spatial alignment, personalized SBS simulations were produced using a multimaterial 3D printer. The fidelity of the models was assessed by 3 experienced neurosurgeons, and the effects for anatomic education and surgical training were evaluated by 10 resident trainees. Both evaluations were based on 5-point Likert questionnaires.

RESULTS

The mean scores for fidelity of tissue structure ranged from 3.7 to 4.7, and scores for aid in anatomic education and surgical training ranged from 3.5 to 4.9.

CONCLUSION

The 3D-printed SBS simulation is a practical, economical, high-fidelity model. It has great potential for anatomic education and operative training in transnasal endoscopic surgery.