scholarly journals Advanced hepatic vasculobiliary imaging segmentation and 3D reconstruction as an aid in the surgical management of high biliary stenosis

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nuno Pereira da Silva ◽  
Inês Abreu ◽  
Marco Serôdio ◽  
Luís Ferreira ◽  
Henrique Alexandrino ◽  
...  
Keyword(s):  
3D Reconstruction ◽  
Surgical Planning ◽  
3D Model ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
3D Models ◽  
Anatomical Landmarks ◽  
Biliary Stenosis ◽  
Anatomical Structures ◽  
Ct And Mri

Abstract Background Three-dimensional (3D) models are increasingly used to help surgeons, guiding them through the complex hepatic vasculobiliary anatomy. The biliary tract is a relatively untapped territory with only a few case reports described in medical literature. Our aim is to present an innovative 3D reconstruction methodology for biliary imaging and surgical planning, applied to a case of iatrogenic biliary stricture, with fusion of segmented CT and MRI images. Case presentation A selected case of Bismuth type III iatrogenic biliary stenosis for 3D planning. CT and MR studies were acquired with dedicated protocols for segmentation. Two radiologists performed segmentation and 3D model post-processing, fusing both imaging techniques to faithfully render the anatomical structures. Measurements of anatomical landmarks were taken in both the CT/MRI and the 3D model to assure its accuracy and differences in measurement were calculated. The 3D model replicates anatomical structures and pathology with high accuracy, with only 2.2% variation between STL, CT and MRI measurements. The model was discussed with the surgical team and used in the surgical planning, improving confidence in this delicate procedure, due to the detailed prior knowledge of the patient's anatomy. Conclusion Three-dimensional reconstructions are a rapidly growing area of research with a significant impact in the personalized and precision medicine. The construction of 3D models that combine vascular and biliary anatomy, using different imaging techniques, respectively CT and MRI, will predictably contribute to a more rigorous planning of complex liver surgeries.

scholarly journals Application of Photogrammetric 3D Reconstruction to Scanning Electron Microscopy: Considerations for Volume Analysis

2020 ◽  
Author(s):  
William D. A. Rickard ◽  
Jéssica Fernanda Ramos Coelho ◽  
Joshua Hollick ◽  
Susannah Soon ◽  
Andrew Woods
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
3D Reconstruction ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
3D Models ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Operating Parameters ◽  
Scanning Electron

Photogrammetric three-dimensional (3D) reconstruction is an image processing technique used to develop digital 3D models from a series of two-dimensional images. This technique is commonly applied to optical photography though it can also be applied to microscopic imaging techniques such as scanning electron microscopy (SEM). The authors propose a method for the application of photogrammetry techniques to SEM micrographs in order to develop 3D models suitable for volumetric analysis. SEM operating parameters for image acquisition are explored and the relative effects discussed. This study considered a variety of microscopic samples, differing in size, geometry and composition, and found that optimal operating parameters vary with sample geometry. Evaluation of reconstructed 3D models suggests that the quality of the models strongly determines the accuracy of the volumetric measurements obtainable. In particular, they report on volumetric results achieved from a laser ablation pit and discuss considerations for data acquisition routines.

Application of Photogrammetric 3D Reconstruction to Scanning Electron Microscopy: Considerations for Volume Analysis

2021 ◽  
Vol 2021 (18) ◽  
pp. 60404-1-60404-9
Author(s):  
William D. A. Rickard ◽  
Jéssica Fernanda Ramos Coelho ◽  
Joshua Hollick ◽  
Susannah Soon ◽  
Andrew Woods
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
3D Reconstruction ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
3D Models ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Operating Parameters ◽  
Scanning Electron

Photogrammetric three-dimensional (3D) reconstruction is an image processing technique used to develop digital 3D models from a series of two-dimensional images. This technique is commonly applied to optical photography though it can also be applied to microscopic imaging techniques such as scanning electron microscopy (SEM). The authors propose a method for the application of photogrammetry techniques to SEM micrographs in order to develop 3D models suitable for volumetric analysis. SEM operating parameters for image acquisition are explored and the relative effects discussed. This study considered a variety of microscopic samples, differing in size, geometry and composition, and found that optimal operating parameters vary with sample geometry. Evaluation of reconstructed 3D models suggests that the quality of the models strongly determines the accuracy of the volumetric measurements obtainable. In particular, they report on volumetric results achieved from a laser ablation pit and discuss considerations for data acquisition routines.

scholarly journals Current Applications, Opportunities, and Limitations of AI for 3D Imaging in Dental Research and Practice

2020 ◽  
Vol 17 (12) ◽  
pp. 4424
Author(s):  
Kuofeng Hung ◽  
Andy Wai Kan Yeung ◽  
Ray Tanaka ◽  
Michael M. Bornstein
Keyword(s):  
Treatment Planning ◽  
3D Imaging ◽  
Imaging Techniques ◽  
Current Trend ◽  
Three Dimensional ◽  
Image Data ◽  
Anatomical Landmarks ◽  
Automated Diagnosis ◽  
Dental Practitioners ◽  
Facial Scanning

The increasing use of three-dimensional (3D) imaging techniques in dental medicine has boosted the development and use of artificial intelligence (AI) systems for various clinical problems. Cone beam computed tomography (CBCT) and intraoral/facial scans are potential sources of image data to develop 3D image-based AI systems for automated diagnosis, treatment planning, and prediction of treatment outcome. This review focuses on current developments and performance of AI for 3D imaging in dentomaxillofacial radiology (DMFR) as well as intraoral and facial scanning. In DMFR, machine learning-based algorithms proposed in the literature focus on three main applications, including automated diagnosis of dental and maxillofacial diseases, localization of anatomical landmarks for orthodontic and orthognathic treatment planning, and general improvement of image quality. Automatic recognition of teeth and diagnosis of facial deformations using AI systems based on intraoral and facial scanning will very likely be a field of increased interest in the future. The review is aimed at providing dental practitioners and interested colleagues in healthcare with a comprehensive understanding of the current trend of AI developments in the field of 3D imaging in dental medicine.

scholarly journals Performance of Cone Beam Computed Tomography Systems in Visualizing the Cortical Plate in 3D Image Reconstruction: An In Vitro Study

2018 ◽  
Vol 12 (1) ◽  
pp. 586-595 ◽  
Author(s):  
Abbas Shokri ◽  
Mohammad Reza Jamalpour ◽  
Amir Eskandarloo ◽  
Mostafa Godiny ◽  
Payam Amini ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
3D Reconstruction ◽  
Cortical Bone ◽  
Three Dimensional ◽  
Cortical Plate ◽  
3D Image ◽  
Bone Thickness ◽  
Anatomical Structures ◽  
3D Image Reconstruction ◽  
Dental Procedures

Introduction: Cortical bone is an important anatomical structure and its thickness needs to be determined prior to many dental procedures to ensure treatment success. Imaging modalities are necessarily used in dentistry for treatment planning and dental procedures. Three-dimensional image reconstruction not only provides visual information but also enables accurate measurement of anatomical structures; thus, it is necessarily required for maxillofacial examination and in case of skeletal problems in this region. Aims: This study aimed to assess the ability of three Cone Beam Computed Tomography (CBCT) systems including Cranex 3D, NewTom 3G and 3D Promax for Three-Dimensional (3D) image reconstruction of the cortical plate with variable thicknesses. Methods: Depending on the cortical bone thickness, samples were evaluated in three groups of ≤ 0. 5 mm, 0.6 -1 mm and 1.1-1.5 mm cortical bone thickness. The CBCT scans were obtained from each sample using three systems, their respective FOVs, and 3D scans were reconstructed using their software programs. Two observers viewed the images twice with a two-week interval. The ability of each system in the 3D reconstruction of different thicknesses of cortical bone was determined based on its visualization on the scans. The data were analyzed using SPSS and Kappa test. Results: The three systems showed the greatest difference in the 3D reconstruction of cortical bone with < 0.5 mm thickness. Cranex 3D with 4×6 cm2 FOV had the highest and 3D Promax with 8×8 cm2 FOV had the lowest efficacy for 3D reconstruction of cortical bone. Cranex 3D with 4×6 cm2 and 6×8 cm2 FOVs and NewTom 3G with 5×5 cm2 and 8×5 cm2 FOVs showed significantly higher efficacy for 3D reconstruction of cortical bone with 0.6-1mm thickness while 3D Promax followed by NewTom 3G with 8×8 cm2 FOV had the lowest efficacy for this purpose. Conclusion: Most CBCT systems have high efficacy for 3D image reconstruction of cortical bone with thicknesses over 1 mm while they have poor efficacy for image reconstruction of cortical bone with less than 0.5 mm thickness. Thus, for accurate visualization of anatomical structures on CBCT scans, systems with smaller FOVs and consequently smaller voxel size are preferred.

Effect of 3D Manipulatives on Students with Visual Impairments Who Are Learning Chemistry Constructs: A Pilot Study

2020 ◽  
Vol 114 (5) ◽  
pp. 370-381
Author(s):  
Derrick W. Smith ◽  
Sandra A. Lampley ◽  
Bob Dolan ◽  
Greg Williams ◽  
David Schleppenbach ◽  
...  
Keyword(s):  
Stem Education ◽  
3D Model ◽  
Atomic Orbital ◽  
Visual Impairments ◽  
Three Dimensional ◽  
3D Models ◽  
Specific Content ◽  
3D Printed ◽  
Printed Materials ◽  
Tactile Graphics

Introduction: The emerging technology of three-dimensional (3D) printing has the potential to provide unique 3D modeling to support specific content in science, technology, engineering, and mathematics (STEM) education, particularly chemistry. Method: Seventeen ( n = 17) students with visual impairments were provided direct instruction on chemistry atomic orbital content and allowed to use either print or tactile graphics or 3D models in rotating order. Participants were asked specific content questions based upon the atomic orbitals. Results: The students were asked two sets of comprehension questions: general and specific. Overall, students’ responses for general questions increased per iteration regardless of which manipulative was used. For specific questions, the students answered more questions correctly when using the 3D model regardless of order. When asked about their perceptions toward the manipulatives, the students preferred the 3D model over print or tactile graphics. Discussion: The findings show the potential for 3D printed materials in learning complex STEM content. Although the students preferred the 3D models, they all mentioned that a combination of manipulatives helped them better understand the material. Implications for practitioners: Practitioners should consider the use of manipulatives that include 3D printed materials to support STEM education.

The Relationship of Transepicondylar Width with the Distal and Posterior Femoral Condyles and Its Clinical Implications: A Three-Dimensional Study

2020 ◽  
Author(s):  
Merrill Lee ◽  
Jade Pei Yuik Ho ◽  
Jerry Yongqiang Chen ◽  
Chung Kia Ng ◽  
Seng Jin Yeo ◽  
...  
Keyword(s):  
Three Dimensional ◽  
3D Models ◽  
Ct Images ◽  
Revision Total Knee Arthroplasty ◽  
Joint Line ◽  
Lower Limbs ◽  
Anatomical Landmarks ◽  
Medial Condyle ◽  
Lateral Epicondyle ◽  
Femoral Condyles

Abstract Background Restoration of the anatomical joint line, while important for clinical outcomes, is difficult to achieve in revision total knee arthroplasty (rTKA) due to distal femoral bone loss. The objective of this study was to determine a reliable method of restoring the anatomical joint line and posterior condylar offset in the setting of rTKA based on three-dimensional (3D) reconstruction of computed tomography (CT) images of the distal femur. Methods CT scans of 50 lower limbs were analyzed. Key anatomical landmarks such as the medial epicondyle (ME), lateral epicondyle, and transepicondylar width (TEW) were determined on 3D models constructed from the CT images. Best-fit planes placed on the most distal and posterior loci of points on the femoral condyles were used to define the distal and posterior joint lines, respectively. Statistical analysis was performed to determine the relationships between the anatomical landmarks and the distal and posterior joint lines. Results There was a strong correlation between the distance from the ME to the distal joint line of the medial condyle (MEDC) and the distance from the ME to the posterior joint line of the medial condyle (MEPC) (p < 0.001; r = 0.865). The mean ratio of MEPC to MEDC was 1.06 (standard deviation [SD]: 0.07; range: 0.88–1.27) and that of MEPC to TEW was 0.33 (SD: 0.03; range: 0.25–0.38). Conclusions Our findings suggest that the fixed ratios of MEPC to TEW (0.33) and that of MEPC to MEDC (1.06) provide a reliable means for the surgeon to determine the anatomical joint line when used in combination.

Models partition for 3D printing objects using skeleton

2017 ◽  
Vol 23 (1) ◽  
pp. 54-64 ◽  
Author(s):  
Xiaotong Jiang ◽  
Xiaosheng Cheng ◽  
Qingjin Peng ◽  
Luming Liang ◽  
Ning Dai ◽  
...  
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Principal Component ◽  
3D Models ◽  
Sweep Method ◽  
Final Model ◽  
Content Type ◽  
Working Volume ◽  
Minima Rule ◽  
The Greedy Algorithm

Purpose It is a challenge to print a model with the size that is larger than the working volume of a three-dimensional (3D) printer. The purpose of this paper is to present a feasible approach to divide a large model into small printing parts to fit the volume of a printer and then assemble these parts into the final model. Design/methodology/approach The proposed approach is based on the skeletonization and the minima rule. The skeleton of a printing model is first extracted using the mesh contraction and the principal component analysis. The 3D model is then partitioned preliminarily into many smaller parts using the space sweep method and the minima rule. The preliminary partition is finally optimized using the greedy algorithm. Findings The skeleton of a 3D model can effectively represent a simplified version of the geometry of the 3D model. Using a model’s skeleton to partition the model is an efficient way. As it is generally desirable to have segmentations at concave creases and seams, the cutting position should be located in the concave region. The proposed approach can partition large models effectively to well retain the integrity of meaningful parts. Originality/value The proposed approach is new in the rapid prototyping field using the model skeletonization and the minima rule. Based on the authors’ knowledge, there is no method that concerns the integrity of meaningful parts for partitioning. The proposed method can achieve satisfactory results by the integrity of meaningful parts and assemblability for most 3D models.

METHDOS OF EFFECTIVE DESIGN FOR CREATING OF PARAMETRIC 3D-MODELS OF PRODUCTS USING THE INTERNAL CAPABILITIES OF CAD-PROGRAMS

2020 ◽  
Author(s):  
E. A. Petrakova
Keyword(s):  
Programming Languages ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Parametric Modeling ◽  
Effective Control ◽  
Model Parameters ◽  
Internal Capabilities ◽  
Program Components ◽  
Effective Design

It is known that the development of a three-dimensional parametric model is a creative process, since the same 3D-model can be built in various ways. In the article the methods for effective design of parametric 3D-models with the help of internal capabilities of CAD-program without the use of programming languages (macros) is developed. Using the methods and recommendations discussed in the article on the example of Autodesk Inventor functionality will allow the engineer to design parametric three-dimensional products in CAD-programs in the most rational way, reducing the number of errors. Recommendations for effective control of 3D-model parameters during creating of Assembly parts and 2D-drawings are given. Using the functionality discussed in the article will be useful for engineers using parametric modeling methods to create typical products, optimization and analysis of structures, development of their own database of standard products that are not in the library of CAD-program components.

Computational fluid dynamics in a model of the total cavopulmonary connection reconstructed using magnetic resonance images

2005 ◽  
Vol 15 (S3) ◽  
pp. 61-67 ◽  
Author(s):  
Laura Socci ◽  
Francesca Gervaso ◽  
Francesco Migliavacca ◽  
Giancarlo Pennati ◽  
Gabriele Dubini ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Magnetic Resonance Images ◽  
Total Cavopulmonary Connection ◽  
Anatomical Structures ◽  
Human Bones ◽  
Dimensional Reconstruction ◽  
Recent Developments ◽  
Cavopulmonary Connection

The recent developments in imaging techniques have created new opportunities to give an accurate description of the three-dimensional morphology of vessels. Such three-dimensional reconstruction of anatomical structures from medical images has achieved importance in several applications, such as the reconstruction of human bones, spine portions, and vascular districts.

scholarly journals Influence of Geometric Features Associativity of CAD Class Models on the Process of Their Updating – Comparative Analysis

2021 ◽  
Author(s):  
Grzegorz Świaczny
Keyword(s):  
3D Model ◽  
Three Dimensional ◽  
Optimal Solution ◽  
3D Models ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Initial Design ◽  
The Individual ◽  
Class Models ◽  
Positive Effect

This article deals with the topic of one of the most important features of modern CAx class systems – associativity. The term refers to the ability to form relations (links) between two or more objects (in terms of their selected features), and with the consequence creating an associative (linked) three-dimensional model. The author pays special attention to the very process of creating relations between objects, as it has a key impact on the structural stability of CAD class models, and thus on their susceptibility to possible modifications. To show that not all associativity brings a positive effect, the author presents two examples of its implementation. In order to emphasize the influence of the method of linking individual elements, both examples are based on the same 3D model – a thin-walled part with a positioning pin. That means the geometric form of the default part is the same, whereas only relations of the individual objects of the 3D model change. In the first scenario, correctly defined relations between objects make that the positioning pin offset does not affect the initial design conditions. The second scenario shows an incorrect implementation of associativity, as a result of which the same operation of positioning pin offset gives non-compliance with the initial design conditions and with the consequence an undesirable change in its geometry. The article is an attempt to draw attention to the fact that the associative structure of 3D models is not always equal to the optimal solution. Only the well-thought-out nature of associativity allows to use all its advantages.

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