Immersive Surgical Anatomy of the Retrosigmoid Approach

BACKGROUND: Understanding the anatomy of the human cerebrum, cerebellum, and brainstem and their 3-dimensional (3D) relationships is critical for neurosurgery. Although 3D photogrammetric models of cadaver brains and 2-dimensional images of postmortem brain slices are available, neurosurgeons lack free access to 3D models of cross-sectional anatomy of the cerebrum, cerebellum, and brainstem that can be simulated in both augmented reality (AR) and virtual reality (VR). OBJECTIVE:To create 3D models and AR/VR simulations from 2-dimensional images of cross-sectionally dissected cadaveric specimens of the cerebrum, cerebellum, and brainstem. METHODS:The Klingler method was used to prepare 3 cadaveric specimens for dissection in the axial, sagittal, and coronal planes. A series of 3D models and AR/VR simulations were then created using 360°photogrammetry.RESULTS: High-resolution 3D models of cross-sectional anatomy of the cerebrum, cerebellum, and brainstem were obtained and used in creating AR/VR simulations. Eleven axial, 9 sagittal, and 7 coronal 3D models were created. The sections were planned to show important deep anatomic structures. These models can be freely rotated, projected onto any surface, viewed from all angles, and examined at various magnifications.CONCLUSION: To our knowledge, this detailed study is the first to combine up-to-date technologies (photogrammetry, AR, and VR) for high-resolution 3D visualization of the cross-sectional anatomy of the entire human cerebrum, cerebellum, and brainstem. The resulting 3D images are freely available for use by medical professionals and students for better comprehension of the 3D relationship of the deep and superficial brain anatomy.

Section: Discussionmentioning

confidence: 99%

“…10,11,13,17,18 Others used realistic textures but lacked complete 360°maneuverability. 12,14,15,[19][20][21][22] By contrast, our study models combine realistic features with 360°movement.…”

Section: Techniques For Producing 3d Visualization and Modelsmentioning

confidence: 96%

Three-Dimensional Modeling and Extended Reality Simulations of the Cross-Sectional Anatomy of the Cerebrum, Cerebellum, and Brainstem

Gurses

Hanalıoğlu

Mignucci-Jiménez

et al. 2023

“…Blender was the sole 3D software used to process our 3D models, whereas other investigators have used more commercial software solutions. 2,9,10,21 Compared with other 3D modeling methods, our suggested algorithm does not require knowledge from a dedicated technician. The refined algorithm only required average photographic skills and basic-to-mid-level 3D modeling abilities and relatively few working hours with primarily background computer processing time.…”

Section: Optimizing Technique For Presentation Of Neuroanatomymentioning

confidence: 99%

“…Although, it would have required an unproportionate amount of funds and working hours when comparing with the sufficient quality in the resulting models from our suggested method. We imagine that these different approaches 4,9,10,18,21 to photogrammetric methods could supplement one another and be a feasible and easy-accessible method for rapid production of complete 3D models of all the cranial nerves. This approach needs to be studied further in more cadaver specimens and fine tuning.…”

Section: Limitations and Future Perspectivesmentioning

confidence: 99%

Simplified Easy-Accessible Smartphone-Based Photogrammetry for 3-Dimensional Anatomy Presentation Exemplified With a Photorealistic Cadaver-Based Model of the Intracranial and Extracranial Course of the Facial Nerve

Krogager

Fugleholm

Mathiesen

et al. 2023

BACKGROUND AND OBJECTIVES: Smartphone-based photogrammetry (SMPhP) was recently presented as a practical and simple algorithm to create photorealistic 3-dimensional (3D) models that benefit from volumetric presentation of real anatomic dissections. Subsequently, there is a need to adapt the techniques for realistic depiction of layered anatomic structures, such as the course of cranial nerves and deep intracranial structures; the feasibility must be tested empirically. This study sought to adapt and test the technique for visualization of the combined intracranial and extracranial course of the facial nerve's complex anatomy and analyze feasibility and limitations. METHODS: We dissected 1 latex-injected cadaver head to depict the facial nerve from the meatal to the extracranial portion. A smartphone camera alone was used to photograph the specimen, and dynamic lighting was applied to improve presentation of deep anatomic structures. Three-dimensional models were created with a cloud-based photogrammetry application. RESULTS: Four 3D models were generated. Two models showed the extracranial portions of the facial nerve before and after removal of the parotid gland; 1 model showed the facial nerve in the fallopian canal after mastoidectomy, and 1 model showed the intratemporal segments. Relevant anatomic structures were annotated through a web-viewer platform. The photographic quality of the 3D models provided sufficient resolution for imaging of the extracranial and mastoid portions of the facial nerve, whereas imaging of the meatal segment only lacked sufficient precision and resolution. CONCLUSION: A simple and accessible SMPhP algorithm allows 3D visualization of complex intracranial and extracranial neuroanatomy with sufficient detail to realistically depict superficial and deeper anatomic structures.

“…Immersive anatomy experiences of cranial approaches developed with photogrammetry have been reported by Rodriguez Rubio et al and others. [24][25][26][27] Similarly, Qlone, an app that performs 360°photogrammetry using mobile devices, has been used to create macroscopic and sectional 3D models of the brain and brainstem. 7,28 However, a caveat of photogrammetry is that it is difficult to create 3D models that accurately represent a microsurgical perspective.…”

Section: Photogrammetry: Traditional Vs Our Novel Techniquementioning

confidence: 99%

Anatomic Depth Estimation and Three-Dimensional Reconstruction of Microsurgical Anatomy Using Monoscopic High-Definition Photogrammetry and Machine Learning

González-Romo

Hanalıoğlu

Mignucci-Jiménez

et al. 2022

BACKGROUND: Immersive anatomic environments offer an alternative when anatomic laboratory access is limited, but current three-dimensional (3D) renderings are not able to simulate the anatomic detail and surgical perspectives needed for microsurgical education. OBJECTIVE: To perform a proof-of-concept study of a novel photogrammetry 3D reconstruction technique, converting high-definition (monoscopic) microsurgical images into a navigable, interactive, immersive anatomy simulation. METHODS: Images were acquired from cadaveric dissections and from an open-access comprehensive online microsurgical anatomic image database. A pretrained neural network capable of depth estimation from a single image was used to create depth maps (pixelated images containing distance information that could be used for spatial reprojection and 3D rendering). Virtual reality (VR) experience was assessed using a VR headset, and augmented reality was assessed using a quick response code-based application and a tablet camera. RESULTS: Significant correlation was found between processed image depth estimations and neuronavigation-defined coordinates at different levels of magnification. Immersive anatomic models were created from dissection images captured in the authors' laboratory and from images retrieved from the Rhoton Collection. Interactive visualization and magnification allowed multiple perspectives for an enhanced experience in VR. The quick response code offered a convenient method for importing anatomic models into the real world for rehearsal and for comparing other anatomic preparations side by side. CONCLUSION: This proof-of-concept study validated the use of machine learning to render 3D reconstructions from 2-dimensional microsurgical images through depth estimation. This spatial information can be used to develop convenient, realistic, and immersive anatomy image models.