Mental visualization of objects from cross-sectional images

Virtual Reality for Preoperative Surgical Planning in Complex Pediatric Oncology

Background: Virtual reality modeling (VRM) is a 3-dimensional simulation created from patient-specific 2-dimensional (2D) imaging. VRM creates a more accurate representation of the patient anatomy and can improve anatomical perception. We surveyed surgeons on their operative plan in complex pediatric oncology cases based on review of 2D imaging and subsequently after review of VRM. We hypothesized that the confidence level would increase with the use of virtual reality and that VRM may change the operative plan. Methods: Patients were selected and enrolled based on age (<18) and oncological diagnosis. VRM was created based on the 2D imaging. Surgeons identified surgical plans based on 2D imaging and again after VRM. A blinded surgeon not involved with the case also gave opinions on surgical plans after viewing both the 2D and the VRM imaging. These assessments were compared with the actual operation. Results: A total of 12 patients were enrolled. Diagnoses included six neuroblastomas, two Wilms tumors, one Ewing's sarcoma, one pseudopapillary tumor of the pancreas, one rhabdomyosarcoma, and one mediastinal germ cell tumor. VRM increased the operating surgeon's confidence 63% of the time. The operative plan changed 8.3% of the time after VRM. Conclusion: VRM is useful to help clarify operative plans for more complex pediatric cases.

Virtual reality applications in pediatric surgery

Virtual reality modeling (VRM) is a 3-dimensional (3D) simulation. It is a powerful tool and has multiple uses and applications in pediatric surgery. Patient-specific 2-dimensional imaging can be used to generate a virtual reality model, which can improve anatomical perception and understanding, and can aid in preoperative planning for complex operations. VRM can also be used for realistic training and simulation. It has also proven effective in distraction for pediatric patients experiencing pain and/or anxiety. We detail the technical requirements and process required for VRM generation, the applications, and future directions.

Multimodal Three-Dimensional Visualization Enhances Novice Learner Interpretation of Basic Cross-Sectional Anatomy

While integrated delivery of anatomy and radiology can support undergraduate anatomical education, the interpretation of complex three-dimensional spatial relationships in cross-sectional and radiological images is likely to be demanding for novices. Due to the value of technology-enhanced and multimodal strategies, it was hypothesized that simultaneous digital and physical learning could enhance student understanding of cross-sectional anatomy. A novel learning approach introduced at a United Kingdom university medical school combined visualization table-based thoracic cross-sections and digital models with a three-dimensional printed heart. A mixed-method experimental and survey approach investigated student perceptions of challenging anatomical areas and compared the multimodal intervention to a two-dimensional cross-section control. Analysis of seven-point Likert-type responses of new medical students (n = 319) found that clinical imaging (mean 5.64 SD ± 1.20) was significantly more challenging (P < 0.001) than surface anatomy (4.19 ± 1.31) and gross anatomy (4.92 ± 1.22). Pre-post testing of students who used the intervention during their first anatomy class at medical school (n = 229), identified significant increases (P < 0.001) in thoracic cross-sectional anatomy interpretation performance (mean 31.4% ± 15.3) when compared to the subsequent abdominal control activity (24.1% ± 17.6). Student test scores were independent of mental-rotation ability. As depicted on a seven-point Likert-type scale, the intervention may have contributed to students considering cross-sectional interpretation of thoracic images (4.2 ± 1.23) as significantly less challenging (P < 0.001) than comparable abdominal images (5.59 ± 1.14). These findings could have implications for how multimodal cross-sectional anatomy learning approaches are implemented within medical curricula.

Interdimensional Travel: Visualisation of 3D-2D Transitions in Anatomy Learning

Clinical image interpretation is one of the most challenging activities for students when they first arrive at medical school. Interpretation of clinical images concerns the identification of three-dimensional anatomical features in two-dimensional cross-sectional computed tomography (CT) and magnetic resonance imaging (MRI) images in axial, sagittal and coronal planes, and the recognition of structures in ultrasound and plain radiographs. We propose that a cognitive transition occurs when initially attempting to interpret clinical images, which requires reconciling known 3D structures with previously unknown 2D visual information. Additionally, we propose that this 3D-2D transition is required when integrating an understanding of superficial 2D surface landmarks with an appreciation of underlying 3D anatomical structures during clinical examinations.Based on educational theory and research findings, we recommend that 3D and 2D approaches should be simultaneously combined within radiological and surface anatomy education. With a view to this, we have developed and utilised digital and art-based methods to support the 3D-2D transition. We outline our observations and evaluations, and describe our practical implementation of these approaches within medical curricula to serve as a guide for anatomy educators. Furthermore, we define the theoretical underpinnings and evidence supporting the integration of 3D-2D approaches and the value of our specific activities for enhancing the clinical image interpretation and surface anatomy learning of medical students.

Visual completion from 2D cross-sections: Implications for visual theory and STEM education and practice

Accurately inferring three-dimensional (3D) structure from only a cross-section through that structure is not possible. However, many observers seem to be unaware of this fact. We present evidence for a 3D amodal completion process that may explain this phenomenon and provide new insights into how the perceptual system processes 3D structures. Across four experiments, observers viewed cross-sections of common objects and reported whether regions visible on the surface extended into the object. If they reported that the region extended, they were asked to indicate the orientation of extension or that the 3D shape was unknowable from the cross-section. Across Experiments 1, 2, and 3, participants frequently inferred 3D forms from surface views, showing a specific prior to report that regions in the cross-section extend straight back into the object, with little variance in orientation. In Experiment 3, we examined whether 3D visual inferences made from cross-sections are similar to other cases of amodal completion by examining how the inferences were influenced by observers’ knowledge of the objects. Finally, in Experiment 4, we demonstrate that these systematic visual inferences are unlikely to result from demand characteristics or response biases. We argue that these 3D visual inferences have been largely unrecognized by the perception community, and have implications for models of 3D visual completion and science education.

Virtual Sectioning and Haptic Exploration of Volumetric Shapes in the Absence of Visual Feedback

The reduced behavior for exploration of volumetric data based on the virtual sectioning concept was compared with the free scanning at the use of the StickGrip linkage-free haptic device. Profiles of the virtual surface were simulated through the penholder displacements in relation to the pen tip of the stylus. One or two geometric shapes (cylinder, trapezoidal prism, ball, and torus) or their halves and the ripple surface were explored in the absence of visual feedback. In the free scanning, the person physically moved the stylus. In the parallel scanning, cross-sectional profiles were generated automatically starting from the location indicated by the stylus. Analysis of the performance of 18 subjects demonstrated that the new haptic visualization and exploration technique allowed to create accurate mental images, to recognize and identify virtual shapes. The mean number of errors was about 2.5% in the free scanning mode and 1.9% and 1.5% in the parallel scanning mode at the playback velocity of 28 mm/s and 42 mm/s, respectively. All participants agreed that the haptic visualization of the 3D virtual surface presented as the cross-sectional slices of the workspace was robust and easy to use. The method was developed for visualization of spatially distributed data collected by sensors.

In-lab three-dimensional printing: an inexpensive tool for experimentation and visualization for the field of organogenesis

The development of the microscope in 1590 by Zacharias Janssenby and Hans Lippershey gave the world a new way of visualizing details of morphogenesis and development. More recent improvements in this technology including confocal microscopy, scanning electron microscopy (SEM) and optical projection tomography (OPT) have enhanced the quality of the resultant image. These technologies also allow a representation to be made of a developing tissue’s three-dimensional (3-D) form. With all these techniques however, the image is delivered on a flat two-dimensional (2-D) screen. 3-D printing represents an exciting potential to reproduce the image not simply on a flat screen, but in a physical, palpable three-dimensional structure. Here we explore the scope that this holds for exploring and interacting with the structure of a developing organ in an entirely novel way. As well as being useful for visualization, 3-D printers are capable of rapidly and cost-effectively producing custom-made structures for use within the laboratory. We here describe the advantages of producing hardware for a tissue culture system using an inexpensive in-lab printer.