Rapid-prototyped temporal bone and inner-ear models replicated by adjusting computed tomography thresholds

2007 ◽  
Vol 121 (11) ◽  
pp. 1025-1028 ◽  
Author(s):  
M Suzuki ◽  
A Hagiwara ◽  
Y Ogawa ◽  
H Ono

AbstractPurpose:This study aimed to investigate the validity of adjusting computed tomography thresholds in order to replicate a temporal bone model suitable for dissection training and education.Materials and methods:A simulated three-dimensional model of a human temporal bone was prototyped using selective laser sintering. The powder layers were laser-fused, based on detailed computed tomography data, and accumulated to create a three-dimensional structure. The computed tomography threshold value of the stapes was modified on standard triangular language file in order to replicate the stapes. The intensity value was determined to select the fluid lumen of the inner ear and the bone surface, in order to replicate the inner ear.Results:The model could be shaved, using surgical instruments, in the same manner as during real surgery. The stapes could be reproduced, making this model even more realistic than a previous version. The inner ear was recreated, along with the surrounding bony wall and the ossicles.Conclusion:This model facilitates dissection training and easy understanding of the relation between the labyrinth and the surrounding structures.

2009 ◽  
Vol 124 (5) ◽  
pp. 564-568 ◽  
Author(s):  
M Suzuki ◽  
Y Ogawa ◽  
T Hasegawa ◽  
S Kawaguchi ◽  
K Yukawa ◽  
...  

AbstractAim:To examine the usefulness of a three-dimensional model for surgical navigation of cholesteatoma.Materials and method:A three-dimensional model was prototyped using selective laser sintering. Based on detailed computed tomography data, powder layers were laser-fused and accumulated to create a three-dimensional structure. The computed tomography threshold was adjusted to simultaneously replicate bony structures and soft tissues.Results:The cholesteatoma, major vessels and bony structures were well replicated. This laser-sintered model was used to aid surgery for recurrent cholesteatoma. The cholesteatoma, which extended from the hypotympanum through the styloid process sheath and the internal carotid artery sheath, was removed safely via a minimal skin incision.Conclusion:The laser-sintered model was useful for surgical planning and navigation in a cholesteatoma case involving complex bony structures and soft tissue.


Author(s):  
Beomcho Jun ◽  
Sunwha Song

Abstract Objective This paper describes the construction of portals for electrode placement during cochlear implantation and emphasises the utility of pre-operative temporal bone three-dimensional computed tomography. Methods Temporal bone three-dimensional computed tomography was used to plan portal creation for electrode insertion. Results Pre-operative temporal bone three-dimensional computed tomography can be used to determine the orientation of temporal bone structures, which is important for mastoidectomy, posterior tympanotomy and cochleostomy, and when using the round window approach. Conclusion It is essential to create appropriate portals (from the mastoid cortex to the cochlea) in a step-by-step manner, to ensure the safe insertion of electrodes into the scala tympani. Pre-operative three-dimensional temporal bone computed tomography is invaluable in this respect.


2021 ◽  
pp. 205141582110002
Author(s):  
Lorenz Berger ◽  
Aziz Gulamhusein ◽  
Eoin Hyde ◽  
Matt Gibb ◽  
Teele Kuusk ◽  
...  

Objective: Surgical planning for robotic-assisted partial nephrectomy is widely performed using two-dimensional computed tomography images. It is unclear to what extent two-dimensional images fully simulate surgical anatomy and case complexity. To overcome these limitations, software has been developed to reconstruct three-dimensional models from computed tomography data. We present the results of a feasibility study, to explore the role and practicality of virtual three-dimensional modelling (by Innersight Labs) in the context of surgical utility for preoperative and intraoperative use, as well as improving patient involvement. Methods: A prospective study was conducted on patients undergoing robotic-assisted partial nephrectomy at our high volume kidney cancer centre. Approval from a research ethics committee was obtained. Patient demographics and tumour characteristics were collected. Surgical outcome measures were recorded. The value of the three-dimensional model to the surgeon and patient was assessed using a survey. The prospective cohort was compared against a retrospective cohort and cases were individually matched using RENAL (radius, exophytic/endophytic, nearness to collecting system or sinus, anterior/posterior, location relative to polar lines) scores. Results: This study included 22 patients. Three-dimensional modelling was found to be safe for this prospective cohort and resulted in good surgical outcome measures. The mean (standard deviation) console time was 158.6 (35) min and warm ischaemia time was 17.3 (6.3) min. The median (interquartile range) estimated blood loss was 125 (50–237.5) ml. Two procedures were converted to radical nephrectomy due to the risk of positive margins during resection. The median (interquartile range) length of stay was 2 (2–3) days. No postoperative complications were noted and all patients had negative surgical margins. Patients reported improved understanding of their procedure using the three-dimensional model. Conclusion: This study shows the potential benefit of three-dimensional modelling technology with positive uptake from surgeons and patients. Benefits are improved perception of vascular anatomy and resection approach, and procedure understanding by patients. A randomised controlled trial is needed to evaluate the technology further. Level of evidence: 2b


2017 ◽  
Vol 2017 ◽  
pp. 1-13
Author(s):  
Xin Wan ◽  
Ximing Liu ◽  
Jichen Miao ◽  
Peng Cong ◽  
Yuai Zhang ◽  
...  

Pebble dynamics is important for the safe operation of pebble-bed high temperature gas-cooled reactors and is a complicated problem of great concern. To investigate it more authentically, a computed tomography pebble flow detecting (CT-PFD) system has been constructed, in which a three-dimensional model is simulated according to the ratio of 1 : 5 with the core of HTR-PM. A multislice helical CT is utilized to acquire the reconstructed cross-sectional images of simulated pebbles, among which special tracer pebbles are designed to indicate pebble flow. Tracer pebbles can be recognized from many other background pebbles because of their heavy kernels that can be resolved in CT images. The detecting principle and design parameters of the system were demonstrated by a verification experiment on an existing CT system in this paper. Algorithms to automatically locate the three-dimensional coordinates of tracer pebbles and to rebuild the trajectory of each tracer pebble were presented and verified. The proposed pebble-detecting and tracking technique described in this paper will be implemented in the near future.


2014 ◽  
Vol 128 (5) ◽  
pp. 416-420 ◽  
Author(s):  
N Ahmad ◽  
A Wright

AbstractObjective:To produce a high-resolution, three-dimensional temporal bone model from serial sections, using a personal computer.Method:Digital images were acquired from histological sections of the temporal bone. Image registration, segmentation and three-dimensional volumetric reconstruction were performed using a personal computer. The model was assessed for anatomical accuracy and interactivity by otologists.Results:An accurate, high-resolution, three-dimensional model of the temporal bone was produced, containing structures relevant to otological surgery. The facial nerve, labyrinth, internal carotid artery, jugular bulb and all of the ossicles were seen (including the stapes footplate), together with the internal and external auditory meati. Some projections also showed the chorda tympani nerve.Conclusion:A high-resolution, three-dimensional computer model of the complete temporal bone was produced using a personal computer. Because of the increasing difficulty in procuring cadaveric bones, this model could be a useful adjunct for training.


2020 ◽  
Vol 6 (4) ◽  
pp. 41-45
Author(s):  
Sergey V. Leonov ◽  
Julia P. Shakiryanova

Background: The article presents our own experience of using computer tomography for identification of individuals with known results. Aims: The aim of the study was to verify the possibility of performing an identification study using a three-dimensional model obtained from computed tomography of the head. Identification was performed using a three-dimensional model of the head, based on computer tomography sections made in various projections, with a step of 1.231.25 mm. Two-dimensional images of the face (photos) were used for comparison. All comparative studies were conducted using approved methods of craniofacial and portrait identification: by reference points and contours. The experiment used a computer program that allows you to export DICOM-files of computed tomography results to other formats (InVesalius), as well as computer programs that directly work with the research objects (Autodesk 3ds Max, alternative programs Adobe Photoshop, Smith Micro Poser Pro). Results: In the course of research, it was found that, having computer tomography data of the head, it is possible to conduct identification studies on the following parameters: on the reconstructed three-dimensional model of the soft tissues of the face, on the three-dimensional model of the skull (craniofacial identification), on the features of the structure of the ear. Conclusion: Positive results were obtained when comparing objects, which makes it advisable to use them in practical and scientific activities.


2005 ◽  
Vol 119 (9) ◽  
pp. 693-698 ◽  
Author(s):  
Beom-Cho Jun ◽  
Sun-Wha Song ◽  
Ju-Eun Cho ◽  
Chan-Soon Park ◽  
Dong-Hee Lee ◽  
...  

The aim of this study was to investigate the usefulness of a three-dimensional (3D) reconstruction of computed tomography (CT) images in determining the anatomy and topographic relationship between various important structures. Using 40 ears from 20 patients with various otological diseases, a 3D reconstruction based on the image data from spiral high-resolution CT was performed by segmentation, volume-rendering and surface-rendering algorithms on a personal computer. The 3D display of the middle and inner ear structures was demonstrated in detail. Computer-assisted measurements, many of which could not be easily measured in vivo, of the reconstructed structures provided accurate anatomic details that improved the surgeon’s understanding of spatial relationships. A 3D reconstruction of temporal bone CT might be useful for education and increasing understanding of the anatomical structures of the temporal bone. However, it will be necessary to confirm the correlation between the 3D reconstructed images and histological sections through a validation study.


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