Download or read book Automated Microct Based Bone And Articular Cartilage Analysis Using Iterative Shape Averaging And Atlas Based Registration written by Lucas Junginger and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: INTRODUCTION: Micro-computed tomography (u00b5CT) is a gold standard modality for 3D assessment of bone. Contrast-enhanced (CE)-u00b5CT is emerging as a powerful technology for 3D characterization of articular cartilage (AC) tissue, historically assessed via 2D histology. Volume-of-interest (VOI) selection of these tissues generally involves manual contouring, which is time consuming and leads to inter- and intra-observer variability. AC is also often analyzed in tandem with adjacent subchondral bone, further compounding these issues. The limitations of manual contouring can be mitigated by the application of semi-automated or fully automated segmentation, but given the inherent complexity of the joint tissues being imaged, few automated segmentation techniques have been described for u00b5CT imaging. Atlas-based tissue segmentation is an effective technique in which a pre-segmented, representative set of tissue volumes (an u201catlasu201d) is generated and registered onto an unknown image, automatically segmenting the tissues of the unknown image. Here we demonstrate the use of iterative shape averaging (ISA) to generate a multi-tissue atlas to automatically segment and analyze multiple tissues from u00b5CT data.METHODS: Under IACUC-approved protocols for unrelated studies, dissected distal femora from 50 adult Lewis rats (25 healthy limbs, 25 post-ACL rupture) were incubated in the contrast agent ioxaglate and underwent CE-u00b5CT imaging (u00b5CT-40, Scanco Medical) with 12 u00b5m voxel size. An experienced user performed manual VOI selection of epiphyseal trabecular bone and AC using manual contouring followed by intensity thresholding. These samples were then randomized into training sets of 1, 3, 5, 10, and 20 samples (n=10 sets/group), and all other samples in the set were assigned to the test group. For the 1-sample atlas, a randomly selected sample was chosen as a representative atlas and registered onto test images. For all other groups, the training images were used to generate an average atlas using ISA (Fig. 1A). Briefly, training images were rigidly co-registered onto a random reference image, and an initial average was created. Subsequent rounds of non-rigid registration (NRR) iteratively refined the average until it converged on an average image and corresponding average multi-tissue atlas. Each atlas was then registered onto 10 randomly selected test images to segment epiphyseal bone and AC volumes. Segmentations were assessed against manual VOIs in terms of Dice similarity coefficient (DSC), sensitivity, and specificity. Bone densitometry and morphometry and AC morphology measures were also calculated from each volume, and percent (%) error was calculated between atlas-based and manual segmentations. Differences were assessed via one-way ANOVA with a Bonferroni correction for multiple comparisons.RESULTS: Mean DSC and sensitivity for epiphyseal bone and AC increased with the number of input samples to the atlases, particularly DSC of AC tissue (Fig. 1B). Percent error for bone parameters and AC volume was within u00b15%, with decreased variance in atlases built from 10 or 20 training samples. Percent error in AC thickness was higher but remained within u00b110% (Fig. 1D). Atlases with 1, 3, and 5 inputs had rare cases of gross mal-registration of both bone and AC (Fig. 1C, D), whereas those from 10 and 20 inputs had no cases of mal-registration. The rate of highly accurate registration (DSC > 0.85) generally increased as more inputs were added (Fig. 1C).DISCUSSION: Automated segmentation of AC and bone from u00b5CT scans can be performed on healthy and degenerate femora with high accuracy via ISA and atlas-based segmentation. Atlases built from few samples were capable of accurate registration in most cases but were more prone to mal-registration. Incorporating more training images produced a more robust atlas, and 10 training images were sufficient to eliminate mal-registration. Bone morphometric and densitometric parameters all fell within u00b15% of those from manual segmentation. AC thickness was more variable u2013 within u00b110% error u2013 likely due to the much smaller tissue volume compared to epiphyseal bone. AC is generally adjacent to thicker tissues including ligament insertion sites and other soft tissues, and small differences in the tissue border can significantly impact resultant volume and thickness. Many parameters consistently exhibited positive or negative error, suggesting bias between manual and atlas-based segmentation, rather than inaccuracy, as the main source of error. In AC, where thickness increases near soft tissue borders, negative error in thickness and volume suggests that borders on atlas-derived VOIs may be more conservative than manual VOIs. This should not be taken to represent a weakness in either atlas-based or manual VOI selection, but rather an inherent difference in the two strategies.SIGNIFICANCE: Tissue segmentation is a highly time- and labor-intensive process and a source of variability in both preclinical and clinical imaging studies of joint tissues. Our work demonstrates that atlas-based segmentation could be a powerful tool to enable significantly faster and more consistent joint tissue segmentation of both healthy and degenerate limbs, accelerating the rate and sensitivity of imaging-based research.

Download or read book MRI Quantification of Cartilage of the Knee written by Julio Carballido Gamio and published by . This book was released on 2005 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Osteoarthritis (OA) of the knee is a chronic disease that is characterized by degeneration of articular cartilage. Magnetic resonance imaging (MRI) allows the visualization and quantification of this degeneration in vivo. In this dissertation the development of new image processing techniques and application of existing ones to perform inter-subject comparison of knee cartilage thickness are presented. The main characteristic of the proposed method is the registration of cartilage surfaces based on the registration of the corresponding bones. The process is semi-automatic since steps involving segmentation require interaction. Cartilage is segmented using Bezier splines and edge detection, and its shape is then interpolated using a morphing technique to create isotropic voxels. The bones corresponding to the segmented cartilage are segmented with a similar approach and registered based on landmarks. The registration can be rigid-body for intra-subject or elastic for inter-subject comparisons. Landmarks are automatically selected based on shape matching using 3D shape-contexts. Visualization of cartilage thickness maps in three dimensions or overlaid on the MR images is also demonstrated. The cartilage segmentation and the morphing technique were validated visually and based on volumetric measurements of images of porcine knees which cartilage volumes were directly measured using a water displacement method. The registration techniques were validated visually and using manual landmark registration. Results showed a good agreement between the digital volumetric measurement from the morphed cartilage and the water displacement method with correlation values of 8.3 (p

Download or read book Cell Based Approaches for Modulating Cartilage and Bone Phenotype written by Roberto Narcisi and published by Frontiers Media SA. This book was released on 2021-12-22 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Atlas based Segmentation of Temporal Bone Anatomy written by Tong Liang and published by . This book was released on 2017 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this research, we proposed an atlas-based automated segmentation approach which used 6 manually traced CT volumes (including the reference CT volume) to construct the atlas. We then registered the test CT volumes to a single reference volume. A series of morphological processes were implemented to segment the temporal bone anatomy. A 3D-view based tracing tool `VolEditor’ was used to provide the manual tracing results of the test data to compare with our automatic segmentations. The validation results of our method on 20 test clinical CT volumes (10 left, 10 right) resulted in average DICE similarity coefficients over 0.6 for cochlea, malleus and incus and ranged from 0.46 to 0.64 for facial nerve, semi-circular canals and vestibule. The proposed method didn’t reach the precision required for surgical planning but was effective for segmenting structures required in surgical simulation software. Additionally, we determined that the 3D manual tracing tool, used in this study, resulted in segmentation errors that caused degradation of the validation results.

Download or read book Automated and Computationally Efficient Joint Motion Analysis Using Low Quality Fluoroscopy Images written by Soheil Ghafurian and published by . This book was released on 2017 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt: The kinematic analysis of joint motion has proven to significantly improve orthopedic surgeries by enhancing surgery assessment, prosthesis design, and pathology diagnosis. This analysis is usually performed by a three to two dimensional (3D/2D) registration of the 3D bone model to a 2D radiographic video from C-arm fluoroscopy imaging machines. However, the practicality of such analysis is undermined due to lengthy and user-dependent 3D/2D image registration algorithms and the high cost of C-arm fluoroscopy imaging machines. Mini C-arm fluoroscopic machines are a more affordable alternative, but the low quality of their images has hindered their use in this application. In this thesis, we propose a novel 3D/2D image registration algorithm for the kinematic analysis of joint bones using mini C-arm fluoroscopy machines with significantly improved speed, despite their low quality images. This method performs a fast registration through a novel algorithm for quick and high-quality generation of digitally reconstructed radiographs (DRR), which is the bottleneck in such processes. Moreover, the dependency of the results on the user has been reduced as a new feature-based registration algorithm replaced the previously manual initialization phase of the process. This algorithm is able to reach the true registration from within 90 degrees of it, which is a substantial improvement over the existing methods. In addition, our algorithm performs the registration in significantly reduced time due to a smaller number of generated DRRs.

Download or read book Medical Imaging 2008 written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Medical Imaging Systems written by Andreas Maier and published by Springer. This book was released on 2018-08-02 with total page 263 pages. Available in PDF, EPUB and Kindle. Book excerpt: This open access book gives a complete and comprehensive introduction to the fields of medical imaging systems, as designed for a broad range of applications. The authors of the book first explain the foundations of system theory and image processing, before highlighting several modalities in a dedicated chapter. The initial focus is on modalities that are closely related to traditional camera systems such as endoscopy and microscopy. This is followed by more complex image formation processes: magnetic resonance imaging, X-ray projection imaging, computed tomography, X-ray phase-contrast imaging, nuclear imaging, ultrasound, and optical coherence tomography.

Download or read book Micro computed Tomography micro CT in Medicine and Engineering written by Kaan Orhan and published by Springer. This book was released on 2019-07-25 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on applications of micro CT, CBCT and CT in medicine and engineering, comprehensively explaining the basic principles of these techniques in detail, and describing their increasing use in the imaging field. It particularly highlights the scanning procedure, which represents the most crucial step in micro CT, and discusses in detail the reconstruction process and the artifacts related to the scanning processes, as well as the imaging software used in analysis. Written by international experts, the book illustrates the application of micro CT in different areas, such as dentistry, medicine, tissue engineering, aerospace engineering, geology, material engineering, civil engineering and additive manufacturing. Covering different areas of application, the book is of interest not only to specialists in the respective fields, but also to broader audience of professionals working in the fields of imaging and analysis, as well as to students of the different disciplines.

Download or read book Small Animal Imaging written by Fabian Kiessling and published by Springer. This book was released on 2017-05-22 with total page 871 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is a practical guide to the use of small animal imaging in preclinical research that will assist in the choice of imaging modality and contrast agent and in study design, experimental setup, and data evaluation. All established imaging modalities are discussed in detail, with the assistance of numerous informative illustrations. While the focus of the new edition remains on practical basics, it has been updated to encompass a variety of emerging imaging modalities, methods, and applications. Additional useful hints are also supplied on the installation of a small animal unit, study planning, animal handling, and cost-effective performance of small animal imaging. Cross-calibration methods and data postprocessing are considered in depth. This new edition of Small Animal Imaging will be an invaluable aid for researchers, students, and technicians involved in research into and applications of small animal imaging.

Download or read book Deep Learning in Medical Image Analysis written by Gobert Lee and published by Springer Nature. This book was released on 2020-02-06 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents cutting-edge research and applications of deep learning in a broad range of medical imaging scenarios, such as computer-aided diagnosis, image segmentation, tissue recognition and classification, and other areas of medical and healthcare problems. Each of its chapters covers a topic in depth, ranging from medical image synthesis and techniques for muskuloskeletal analysis to diagnostic tools for breast lesions on digital mammograms and glaucoma on retinal fundus images. It also provides an overview of deep learning in medical image analysis and highlights issues and challenges encountered by researchers and clinicians, surveying and discussing practical approaches in general and in the context of specific problems. Academics, clinical and industry researchers, as well as young researchers and graduate students in medical imaging, computer-aided-diagnosis, biomedical engineering and computer vision will find this book a great reference and very useful learning resource.

Download or read book Micro Tomographic Atlas of the Mouse Skeleton written by Itai A. Bab and published by Springer Science & Business Media. This book was released on 2007-12-27 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Micro-Tomographic Atlas of the Mouse Skeleton provides a unique systematic description of all calcified components of the mouse. It includes about 200 high resolution, two and three dimensional m CT images of the exterior and interiors of all bones and joints. In addition, the spatial relationship of bones within complex skeletal units is also described. The images are accompanied by detailed explanatory text, thus highlighting special features and newly reported structures. The Atlas fulfils an emerging need for a comprehensive reference to assist both trained and in-training researchers.

Download or read book Information Processing in Medical Imaging written by Chris Taylor and published by Springer Science & Business Media. This book was released on 2003-07-11 with total page 714 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the refeered proceedings of the 18th Interational Conference on Information Processing in Medical Imaging, IPMI 2003, held in UK, in July 2003. The 57 revised full papers presented were carefully reviewed and selected from submissions. The papers are organized in topical sections shape modeling, shape analysis, segmentation, color, performance characterization, registration and modeling similarity, registration and modeling deformation, cardiac motion, fMRI analysis, and diffusion imaging and tractography.

Download or read book Shape in Medical Imaging written by Martin Reuter and published by Springer Nature. This book was released on 2020-10-02 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book constitutes the proceedings of the International Workshop on Shape in Medical Imaging, ShapeMI 2020, which was held in conjunction with the 23rd International Conference on Medical Image Computing and Computer Assistend Intervention, MICCAI 2020, in October 2020. The conference was planned to take place in Lima, Peru, but changed to a virtual format due to the COVID-19 pandemic. The 12 full papers included in this volume were carefully reviewed and selected from 18 submissions. They were organized in topical sections named: methods; learning; and applications.

Download or read book Skeletal Tissue Mechanics written by R. Bruce Martin and published by Springer. This book was released on 2015-10-29 with total page 513 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook describes the biomechanics of bone, cartilage, tendons and ligaments. It is rigorous in its approach to the mechanical properties of the skeleton yet it does not neglect the biological properties of skeletal tissue or require mathematics beyond calculus. Time is taken to introduce basic mechanical and biological concepts, and the approaches used for some of the engineering analyses are purposefully limited. The book is an effective bridge between engineering, veterinary, biological and medical disciplines and will be welcomed by students and researchers in biomechanics, orthopedics, physical anthropology, zoology and veterinary science. This book also: Maximizes reader insights into the mechanical properties of bone, fatigue and fracture resistance of bone and mechanical adaptability of the skeleton Illustrates synovial joint mechanics and mechanical properties of ligaments and tendons in an easy-to-understand way Provides exercises at the end of each chapter

Download or read book Fish Physiology Fish Biomechanics written by Robert E. Shadwick and published by Elsevier. This book was released on 2006-02-02 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first in two decades to exclusively integrate physiological and biomechanical studies of fish locomotion, feeding and breathing, making this book both comprehensive and unique. Fish Physiology: Fish Biomechanics reviews and integrates recent developments in research on fish biomechanics, with particular emphasis on experimental results derived from the application of innovative new technologies to this area of research, such as high-speed video, sonomicrometry and digital imaging of flow fields. The collective chapters, written by leaders in the field, provide a multidisciplinary view and synthesis of the latest information on feeding mechanics, breathing mechanics, sensory systems, stability and maueverability, skeletal systems, muscle structure and performance, and hydrodynamics of steady and burst swimming, including riverine passage of migratory species. Book presents concepts in biomechanics, a rapidly expanding area of research First volume in over twenty years on this subject Multi-author volume with contributions by leaders in the field Clear explanations of basic biomechanical principles used in fish research Well illustrated with summary figures and explanatory color diagrams

Download or read book Medical Image Computing and Computer Assisted Intervention MICCAI 2012 written by Nicholas Ayache and published by Springer. This book was released on 2012-08-28 with total page 645 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three-volume set LNCS 7510, 7511, and 7512 constitutes the refereed proceedings of the 15th International Conference on Medical Image Computing and Computer-Assisted Intervention, MICCAI 2012, held in Nice, France, in October 2012. Based on rigorous peer reviews, the program committee carefully selected 252 revised papers from 781 submissions for presentation in three volumes. The third volume includes 79 papers organized in topical sections on diffusion imaging: from acquisition to tractography; image acquisition, segmentation and recognition; image registration; neuroimage analysis; analysis of microscopic and optical images; image segmentation; diffusion weighted imaging; computer-aided diagnosis and planning; and microscopic image analysis.

Download or read book A Practical Guide to Frozen Section Technique written by Stephen R. Peters and published by Springer Science & Business Media. This book was released on 2010-03-20 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Practical Guide to Frozen Section Technique offers an easy to learn approach to frozen section technique in the form of a highly illustrated handbook intended for onsite use in the laboratory. The book begins with a novel, clearly delineated, step by step approach to learning continuous motion brush technique. Emphasis is placed on recognizing and correcting artifacts during the preparation process. The book addresses all of the steps in the preparation of slides from cutting through cover-slipping. The author’s unique, original techniques for tissue embedding including face down embedding in steel well bars, frozen block cryoembedding and paper cryoembedding are detailed. Variables key to the quality of the preparation including block temperature, tissue properties and section thickness are detailed. The book also covers understanding the cryostat and basic maintenance and care.Sections covering techniques used in Mohs dermatologic surgery, and techniques used in basic animal and human research are discussed by noted experts in their field. A Practical Guide to Frozen Section Technique will be of great value to pathologists, pathology residents in training and also experimental pathology researchers that rely upon this methodology to perform tissue analysis in research.