3D MRI Models of the Musculoskeletal System

2021 ◽  
Vol 25 (03) ◽  
pp. 388-396
Author(s):  
Mohammad Samim
Keyword(s):  
Clinical Practice ◽  
3D Model ◽  
Three Dimensional ◽  
3D Models ◽  
Shoulder Injuries ◽  
3D Mri ◽  
Acquisition Strategies ◽  
Structure Morphology ◽  
Computer Based ◽  
Magnetic Resonance Imaging Mri

AbstractComputed tomography (CT) is most commonly used to produce three-dimensional (3D) models for evaluating bone and joint morphology in clinical practice. However, 3D models created from magnetic resonance imaging (MRI) data can be equally effective for comprehensive and accurate assessment of osseous and soft tissue structure morphology and pathology. The quality of 3D MRI models has steadily increased over time, with growing potential to replace 3D CT models in various musculoskeletal (MSK) applications. In practice, a single MRI examination for two-dimensional and 3D assessments can increase the value of MRI and simplify the pre- and postoperative imaging work-up. Multiple studies have shown excellent performance of 3D MRI models in shoulder injuries, in the hip in the setting of femoroacetabular impingement, and in the knee for the creation of bone surface models. Therefore, the utility of 3D MRI postprocessed models is expected to continue to rise and broaden in applications. Computer-based and artificial intelligence–assisted postprocessing techniques have tremendous potential to improve the efficiency of 3D model creation, opening many research avenues to validate the applicability of 3D MRI and establish 3D-specific quantitative assessment criteria. We provide a practice-focused overview of 3D MRI acquisition strategies, postprocessing techniques for 3D model creation, MSK applications of 3D MRI models, and an illustration of cases from our daily clinical practice.

scholarly journals Segmentación de mallas 3d de edificios históricos para levantamiento arquitectónico

2018 ◽  
Vol 9 (18) ◽  
pp. 66
Author(s):  
Borja Javier Herráez ◽  
Eduardo Vendrell
Keyword(s):  
Feature Detection ◽  
3D Model ◽  
Three Dimensional ◽  
Recognition Algorithm ◽  
Mesh Segmentation ◽  
Historic Buildings ◽  
3D Mesh ◽  
Fields Of Study ◽  
Computer Based ◽  
3D Acquisition

<p>Advances in three-dimensional (3D) acquisition systems have introduced this technology to more fields of study, such as archaeology or architecture. In the architectural field, scanning a building is one of the first possible steps from which a 3D model can be obtained and can be later used for visualisation and/or feature analysis, thanks to computer-based pattern recognition tools. The automation of these tools allows for temporal savings and has become a strong aid for professionals, so that more and more methods are developed with this objective. In this article, a method for 3D mesh segmentation focused  on  the representation  of  historic  buildings  is  proposed.  This  type  of  buildings is characterised  by  having singularities  and features in  façades, such  as  doors  or  windows. The  main  objective  is  to  recognise  these  features, understanding them as those parts of the model that differ from the main structure of the building. The idea is to use a recognition algorithm for planar faces that allows users to create a graph showing the connectivity between them, therefore allowing the reflection of the shape of the 3Dmodel. At a later step, this graph is matched against some pre-defined graphs that  represent  the  patterns  to  look  for. Each  coincidence  between  both  graphs  indicate  the  position  of  one  of  the characteristics sought. The developed method has proved to be effective for feature detection and suitable for inclusion in architectural surveying applications.</p>

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.

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.

scholarly journals Fully Automatic Knee Bone Detection and Segmentation on Three-Dimensional MRI

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 123
Author(s):  
Rania Almajalid ◽  
Ming Zhang ◽  
Juan Shan
Keyword(s):  
Bone Structure ◽  
Three Dimensional ◽  
Training Data ◽  
3D Mri ◽  
Detection Model ◽  
Biological Images ◽  
Medical Sector ◽  
Fully Automatic ◽  
Magnetic Resonance Imaging Mri ◽  
Bone Structures

In the medical sector, three-dimensional (3D) images are commonly used like computed tomography (CT) and magnetic resonance imaging (MRI). The 3D MRI is a non-invasive method of studying the soft-tissue structures in a knee joint for osteoarthritis studies. It can greatly improve the accuracy of segmenting structures such as cartilage, bone marrow lesion, and meniscus by identifying the bone structure first. U-net is a convolutional neural network that was originally designed to segment the biological images with limited training data. The input of the original U-net is a single 2D image and the output is a binary 2D image. In this study, we modified the U-net model to identify the knee bone structures using 3D MRI, which is a sequence of 2D slices. A fully automatic model has been proposed to detect and segment knee bones. The proposed model was trained, tested, and validated using 99 knee MRI cases where each case consists of 160 2D slices for a single knee scan. To evaluate the model’s performance, the similarity, dice coefficient (DICE), and area error metrics were calculated. Separate models were trained using different knee bone components including tibia, femur, patella, as well as a combined model for segmenting all the knee bones. Using the whole MRI sequence (160 slices), the method was able to detect the beginning and ending bone slices first, and then segment the bone structures for all the slices in between. On the testing set, the detection model accomplished 98.79% accuracy and the segmentation model achieved DICE 96.94% and similarity 93.98%. The proposed method outperforms several state-of-the-art methods, i.e., it outperforms U-net by 3.68%, SegNet by 14.45%, and FCN-8 by 2.34%, in terms of DICE score using the same dataset.

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.

Design Modification of Additive Manufacturing Parts Using Texture Information of 3D Model

2019 ◽  
Vol 825 ◽  
pp. 19-30
Author(s):  
Tsung Chien Wu ◽  
Jiing Yih Lai ◽  
Yu Wen Tseng ◽  
Chao Yaug Liao ◽  
Ju Yi Lee
Keyword(s):  
Additive Manufacturing ◽  
3D Model ◽  
Three Dimensional ◽  
Texture Mapping ◽  
3D Models ◽  
Surface Shape ◽  
Design Features ◽  
Design Modification ◽  
Texture Information ◽  
Triangular Model

Additive manufacturing (AM) has been commonly used for the prototyping of three-dimensional (3D) models. The input model of the AM technology is a triangular model representing the surface shape of an object. The design features on a triangular model are generally not clear as the vertices are irregularly distributed. If design modification is necessary, it is difficult to segment and extract the meshes from the model. The objective of this study is to propose a method for extracting the design features on an object model by using the texture information. A 3D color model including a triangular model representing the object shape and a texture map describing the object texture is employed. The 3D model is generated by using a set of object images captured from different views surrounding the object. A texture mapping algorithm is then employed to generate the texture map corresponding to the 3D model. With both meshes and texture displayed in a texture mode, a region extraction technique is employed to extract the design features. All parts separated can then be fabricated with an AM machine, and assembled for checking the feasibility of design modification. Several products are employed to demonstrate the feasibility of the proposed technique.

3D MRI of the Hip Joint: Technical Considerations, Advantages, Applications, and Current Perspectives

2021 ◽  
Vol 25 (03) ◽  
pp. 488-500
Author(s):  
Oganes Ashikyan ◽  
Joel Wells ◽  
Avneesh Chhabra
Keyword(s):  
Acetabular Dysplasia ◽  
Three Dimensional ◽  
Resonance Imaging ◽  
3D Mri ◽  
Great Precision ◽  
Conventional Mri ◽  
Labral Tears ◽  
Technical Details ◽  
Magnetic Resonance Imaging Mri ◽  
Technical Considerations

AbstractMagnetic resonance imaging (MRI) is a common choice among various imaging modalities for the evaluation of hip conditions. Conventional MRI with two-dimensional acquisitions requires a significant amount of time and is limited by partial-volume artifacts and suboptimal fluid-to-cartilage contrast. Recent hardware and software advances have resulted in development of novel isotropic three-dimensional (3D) single-acquisition protocols that cover the volume of the entire hip and can be reconstructed in arbitrary planes for submillimeter assessment of bony and labro-cartilaginous structures in their planes of orientation. This technique facilitates superior identification of small labral tears and other hip lesions with better correlations with arthroscopy. In this review, we discuss technical details related to 3D MRI of the hip, its advantages, and its role in commonly encountered painful conditions that can be evaluated with great precision using this technology. The entities described are femoroacetabular impingement with acetabular labral tears, acetabular dysplasia, avascular necrosis, regional tendinopathies and tendon tears, bursitis, and other conditions.

3D MRI in Musculoskeletal Oncology

2021 ◽  
Vol 25 (03) ◽  
pp. 418-424
Author(s):  
Blake C. Jones ◽  
Shivani Ahlawat ◽  
Laura M. Fayad
Keyword(s):  
Tumor Imaging ◽  
Imaging Techniques ◽  
Three Dimensional ◽  
Motion Artifact ◽  
Whole Body ◽  
Acquisition Time ◽  
3D Mri ◽  
Isotropic Resolution ◽  
3D Acquisition ◽  
Magnetic Resonance Imaging Mri

AbstractAdvances in magnetic resonance imaging (MRI) technology now enable the feasible three-dimensional (3D) acquisition of images. With respect to the imaging of musculoskeletal (MSK) tumors, literature is beginning to accumulate on the use of 3D MRI acquisition for tumor detection and characterization. The benefits of 3D MRI, including general advantages, such as decreased acquisition time, isotropic resolution, and increased image quality, are not only inherently useful for tumor imaging, but they also contribute to the feasibility of more specialized tumor-imaging techniques, such as whole-body MRI, and are reviewed here. Disadvantages of 3D acquisition, such as motion artifact and equipment requirements, do exist and are also discussed. Although further study is needed, 3D MRI acquisition will likely prove increasingly useful in the evaluation of patients with tumors of the MSK system.

3D MRI of the Knee

2021 ◽  
Vol 25 (03) ◽  
pp. 455-467
Author(s):  
Faysal Altahawi ◽  
Jason Pierce ◽  
Mercan Aslan ◽  
Xiaojuan Li ◽  
Carl S. Winalski ◽  
...  
Keyword(s):  
Imaging Techniques ◽  
Spin Echo ◽  
Three Dimensional ◽  
Volume Averaging ◽  
Fast Spin Echo ◽  
3D Mri ◽  
Multiplanar Reconstructions ◽  
Out Of Plane ◽  
Magnetic Resonance Imaging Mri ◽  
3D Sequences

AbstractThree-dimensional (3D) magnetic resonance imaging (MRI) of the knee is widely used in musculoskeletal (MSK) imaging. Currently, 3D sequences are most commonly used for morphological imaging. Isotropic 3D MRI provides higher out-of-plane resolution than standard two-dimensional (2D) MRI, leading to reduced partial volume averaging artifacts and allowing for multiplanar reconstructions in any plane with any thickness from a single high-resolution isotropic acquisition. Specifically, isotropic 3D fast spin-echo imaging, with options for tissue weighting similar to those used in multiplanar 2D FSE imaging, is of particular interest to MSK radiologists. New applications for 3D spatially encoded sequences are also increasingly available for clinical use. These applications offer advantages over standard 2D techniques for metal artifact reduction, quantitative cartilage imaging, nerve imaging, and bone shape analysis. Emerging fast imaging techniques can be used to overcome the long acquisition times that have limited the adoption of 3D imaging in clinical protocols.

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