25 research outputs found

    Metricizing\u27 non-metric craniofacial traits: Application of three dimensional geometric morphometric analysis to ancestral identification

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    Non-metric traits are commonly used by anthropologists to distinguish between groups for such things as age, sex, and even ancestry. However, many non-metric traits cannot be measured with traditional osteological tools. While these traditional methods are useful, they do not take individual variation into account. This thesis uses geometric morphometric coordinate data to \u27metricize\u27 such traits and to evaluate their accuracy of correctly assigning unknown individuals to statistically defined groups; A 3-D digitizer was used to collect data from 39 craniofacial landmarks to capture the form of several phenotypic facial characteristics. The sample consisted of individuals from four different geographic locations (Precontact Peru, Historical China, Ancient Nubia, and Modern India). Principal Components Analysis confirmed that geographic groupings could be identified, while Procrustes Analysis and Thin-Plate Splines were used to assess the nature of form variation within and between groups. Discriminant functions calculated the probability of accurately assigning new individuals to their correct geographic group. The results indicate that phenotypic patterns, while variable, can be distinguished in certain populations and used successfully to predict group membership

    Institutional Strategies to Maintain and Grow Imaging Research During the COVID-19 Pandemic

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    Understanding imaging research experiences, challenges, and strategies for academic radiology departments during and after COVID-19 is critical to prepare for future disruptive events. We summarize key insights and programmatic initiatives at major academic hospitals across the world, based on literature review and meetings of the Radiological Society of North America Vice Chairs of Research (RSNA VCR) group. Through expert discussion and case studies, we provide suggested guidelines to maintain and grow radiology research in the postpandemic era

    Clinical situations for which 3D printing is considered an appropriate representation or extension of data contained in a medical imaging examination: Neurosurgical and otolaryngologic conditions

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    BACKGROUND: Medical three dimensional (3D) printing is performed for neurosurgical and otolaryngologic conditions, but without evidence-based guidance on clinical appropriateness. A writing group composed of the Radiological Society of North America (RSNA) Special Interest Group on 3D Printing (SIG) provides appropriateness recommendations for neurologic 3D printing conditions. METHODS: A structured literature search was conducted to identify all relevant articles using 3D printing technology associated with neurologic and otolaryngologic conditions. Each study was vetted by the authors and strength of evidence was assessed according to published guidelines. RESULTS: Evidence-based recommendations for when 3D printing is appropriate are provided for diseases of the calvaria and skull base, brain tumors and cerebrovascular disease. Recommendations are provided in accordance with strength of evidence of publications corresponding to each neurologic condition combined with expert opinion from members of the 3D printing SIG. CONCLUSIONS: This consensus guidance document, created by the members of the 3D printing SIG, provides a reference for clinical standards of 3D printing for neurologic conditions

    The Human in 3D: Advanced Morphometric Analysis of High-Resolution Anatomically Accurate Computed Models

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    Computed virtual models of anatomical structures are proving to be of increasing value in clinical medicine, education and research. With a variety of fields focused on craniofacial and pelvic anatomy there is a need for accurate anatomical models. Recent technological advancements in computer and medical imaging technologies have provided the tools necessary to develop three-dimensional (3D) functional models of human anatomy for use in medicine (surgical planning and education), forensics and engineering (computer-aided design (CAD) and finite element analysis). Traditionally caliper methodologies are used in the quantitative analysis of human anatomy. In order for experts in anatomy and morphometrics to accept a transition to 3D volumetric data, it must be first validated as anatomically accurate. The purpose of this project was to create anatomically accurate models of modern human anatomy through the use of 3D medical imaging, such as multislice computed tomography (CT), and 3D computer modeling and reconstruction. This dissertation attempts to validate the models and address current morphometric methodologies with four separate studies. The important results found in these studies were: 1) Medical image data such as computed tomography scans can be used to create high-resolution anatomically accurate 3D models for education and research purposes. These models can be used in morphometric studies through virtual quantitative analyses. 2) 3D virtual models of the human pelvis are 100% accurate in the estimation of sex in the pelvis, which represents an increase in accuracy over current field methods. 3) 3D virtual models of the human skull are 95.1% accurate in estimating sex in the skull, which represents an increase in accuracy over current field methods. 4) 3D models of craniofacial anatomy can be used for soft tissue depth analysis studies and clinical image data is more representative of living individuals. By testing the imaging and 3D modeling technologies at several levels, we developed new methods for accurately analyzing virtual anatomy for an array of disciplines

    A review of visualization techniques of post-mortem computed tomography data for forensic death investigations

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    Postmortem computed tomography (PMCT) is a standard image modality used in forensic death investigations. Case- and audience-specific visualizations are vital for identifying relevant findings and communicating them appropriately. Different data types and visualization methods exist in 2D and 3D, and all of these types have specific applications. 2D visualizations are more suited for the radiological assessment of PMCT data because they allow the depiction of subtle details. 3D visualizations are better suited for creating visualizations for medical laypersons, such as state attorneys, because they maintain the anatomical context. Visualizations can be refined by using additional techniques, such as annotation or layering. Specialized methods such as 3D printing and virtual and augmented reality often require data conversion. The resulting data can also be used to combine PMCT data with other 3D data such as crime scene laser scans to create crime scene reconstructions. Knowledge of these techniques is essential for the successful handling of PMCT data in a forensic setting. In this review, we present an overview of current visualization techniques for PMCT

    Reduction splint for edentulous patients

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    An off-the-shelf oral splint that is operatively secured to the maxilla and mandible to assist in reduction and provide maintenance of reduction of maxillary and mandibular fractures in the edentulous or partially edentulous patient. The oral splint is fabricated into a plurality of standardized sizes. These sizes are determined by imaging a population of jaws, measuring dimensions thereof, manipulating (e.g., calculating the mean) these dimensions, and generating a size that is representative of a subset of that population. This can be done for all sizes that would represent individuals in that population. The splint itself is fabricated virtually by creating “U-shapesâ€, splitting them horizontally into halves, creating an evacuation channel, and generating a coupling mechanism to hold the halves together. The splint can then be printed or otherwise manufactured

    Custom reduction splint for edentulous patients

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    A custom oral splint that is operatively secured to the maxilla and mandible of a subject/patient to assist in reduction and provide maintenance of reduction of maxillary and mandibular fractures in the edentulous or partially edentulous subject/patient. In this difficult patient population, there are very limited options for maxillomandibular fixation, and none provide stable reduction of fractures. The novel device minimizes operative time and equipment, as well as offers the ability to transition the patient from rigid fixation to elastics postoperatively. The novel device is custom-designed for each patient\u27s degree of bone atrophy, ensuring a high quality, and effective product

    Reduction splint for edentulous patients

    No full text
    An off-the-shelf oral splint that is operatively secured to the maxilla and mandible to assist in reduction and provide maintenance of reduction of maxillary and mandibular fractures in the edentulous or partially edentulous patient. The oral splint is fabricated into a plurality of standardized sizes. These sizes are determined by imaging a population of jaws, measuring dimensions thereof, manipulating (e.g., calculating the mean) these dimensions, and generating a size that is representative of a subset of that population. This can be done for all sizes that would represent individuals in that population. The splint itself is fabricated virtually by creating “U-shapesâ€, splitting them horizontally into halves, creating an evacuation channel, and generating a coupling mechanism to hold the halves together. The splint can then be printed or otherwise manufactured

    Potential use of deep learning techniques for postmortem imaging

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    The use of postmortem computed tomography in forensic medicine, in addition to conventional autopsy, is now a standard procedure in several countries. However, the large number of cases, the large amount of data, and the lack of postmortem radiology experts have pushed researchers to develop solutions that are able to automate diagnosis by applying deep learning techniques to postmortem computed tomography images. While deep learning techniques require a good understanding of image analysis and mathematical optimization, the goal of this review was to provide to the community of postmortem radiology experts the key concepts needed to assess the potential of such techniques and how they could impact their work
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