232,656 research outputs found

    Histological features of the distal third metacarpal bone in thoroughbred racehorses, with and without lateral condylar fractures

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    A detailed histopathological study of the distal third metacarpal bone of Thoroughbred racehorses was undertaken to characterize lesions observed previously on magnetic resonance imaging (MRI). The bones were selected and grouped on the basis of MRI features. Representative sections in different planes were processed for histopathology. All lesions observed in the articular cartilage (AC) and subchondral bone (SCB) were recorded and graded with a scoring system, based partially on the Osteoarthritis Research Society International grading system. The scoring system included the severity of the lesion. Descriptive statistics and linear mixed effects models were performed. A positive correlation was observed between the severity of histopathological changes in the superficial and deeper osteochondral tissues, and between the number of race starts and AC score. Age was not correlated with AC or SCB score. A moderate variation in AC and SCB scores was observed between the groups; however, there were differences within individual bones. Bones with focal palmar necrosis (FPN) showed significant differences in the histological scoring of the AC compared with bones without FPN. Bones with incomplete fractures or larger areas of bone remodelling showed significant differences in SCB pathology when compared with bones with FPN. Haematoidin was detected in areas with excessive SCB and cancellous bone sclerosis and/or irregular bone density. This finding is suggestive of poor blood perfusion in these areas

    Evaluation of Salmon (<i>Salmo salar</i>) and Rainbow Trout (<i>Oncorhynchus mykiss</i>) pin bones using textural analysis and micro X-ray computational tomography

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    Industrially, common problems arise with the deboning pin bone process, where Atlantic Salmon (Salmo salar) and Rainbow Trout (Oncorhynchus mykiss) fillets, post rigor, are subjected to a pulling process to remove the pin bones from the fillet. This study measured the length of pin bones from two species of fish and two different industrial graded weights, and then used a texture analyser and lCT X-ray to measure the pulling force, break point and volume of the pin bones of both species of fish. Results showed that salmon pin bones required significantly higher pulling force to remove pin bones from the fish fillet when compared with Trout pin bones. Interestingly Trout pin bones were significantly longer and stronger than Salmon pin bones, but had significantly lower volume. This research has progressed the issues surrounding pin boning industrially, however, more studies are required in order to understand if these differences affect the overall deboning pin bone process

    Predictive Modelling of Bone Age through Classification and Regression of Bone Shapes

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    Bone age assessment is a task performed daily in hospitals worldwide. This involves a clinician estimating the age of a patient from a radiograph of the non-dominant hand. Our approach to automated bone age assessment is to modularise the algorithm into the following three stages: segment and verify hand outline; segment and verify bones; use the bone outlines to construct models of age. In this paper we address the final question: given outlines of bones, can we learn how to predict the bone age of the patient? We examine two alternative approaches. Firstly, we attempt to train classifiers on individual bones to predict the bone stage categories commonly used in bone ageing. Secondly, we construct regression models to directly predict patient age. We demonstrate that models built on summary features of the bone outline perform better than those built using the one dimensional representation of the outline, and also do at least as well as other automated systems. We show that models constructed on just three bones are as accurate at predicting age as expert human assessors using the standard technique. We also demonstrate the utility of the model by quantifying the importance of ethnicity and sex on age development. Our conclusion is that the feature based system of separating the image processing from the age modelling is the best approach for automated bone ageing, since it offers flexibility and transparency and produces accurate estimate

    Effect of space flight on sodium, copper, manganese and magnesium content in the skeletal bones

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    Sodium content decreased in the human skeletal bones and rose in the rat bones following space flight. In man copper content rose in the femoral bone and decreased in the vertebral body and the sternum, but was unchanged in the rest of the bones. Magnesium content was decreased in the femoral bone and the sternum, and in the vertebrae, but remained unchanged in the rest of the bones. Possible mechanisms of the changes detected are discussed

    Decision Tree Analysis as a Supplementary Tool to Enhance Histomorphological Differentiation when Distinguishing Human from Non-human Cranial Bone in both Burnt and Unburnt States: A feasibility study

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    This feasibility study was undertaken to describe and record the histological characteristics of burnt and unburnt cranial bone fragments from human and non-human bones. Reference series of fully mineralised, transverse sections of cranial bone, from all variables and specimen states were prepared by manual cutting and semi-automated grinding and polishing methods. A photomicrograph catalogue reflecting differences in burnt and unburnt bone from human and non-humans was recorded and qualitative analysis was performed using an established classification system based on primary bone characteristics. The histomorphology associated with human and non-human samples was, for the main part, preserved following burning at high temperature. Clearly, fibro-lamellar complex tissue subtypes, such as plexiform or laminar primary bone, were only present in non-human bones. A decision tree analysis based on histological features provided a definitive identification key for distinguishing human from non-human bone, with an accuracy of 100%. The decision tree for samples where burning was unknown was 96% accurate, and multi-step classification to taxon was possible with 100% accuracy. The results of this feasibility study, strongly suggest that histology remains a viable alternative technique if fragments of cranial bone require forensic examination in both burnt and unburnt states. The decision tree analysis may provide an additional, but vital tool to enhance data interpretation. Further studies are needed to assess variation in histomorphology taking into account other cranial bones, ontogeny, species and burning conditions

    The symptomatology of aneurysmal bone cyst : the value of diagnostic imaging

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    Background: An aneurysmal bone cyst (ABC) is a benign lesion occurring mainly in children. Generally it is found in the metaphyses of long bones and in flat bones. Osteolysis, bone expansion, thinning of the cortex, osseous septa and fluid levels belong to the typical imaging findings in ABC cases. The purpose of the study was to determine the value of imaging methods: plain x-ray films, US, CT and MRI for the diagnosis of aneurysmal bone cyst and to work out the diagnostic algorithm for an ABC suspected on plain radiograms. Material/Methods: The material consists of 72 patients (44 boys, 28 girls) aged 2-23 years (mean age 12 yrs) with bone lesions diagnosed as aneurysmal bone cysts on pathologic examination. In all patients, plain radiographs were performed, in 26 - sonography (US), in 41 - computed tomography (CT), in 8 - magnetic resonance imaging (MRI). All the examinations were analyzed according to own system of evaluation of typical presentation in the particular methods. The histopathological diagnosis was established after biopsy or surgery. Results: The aneurysmal bone cysts were most frequently located in the long bones of the lower limbs (43%), in the long bones of the upper limbs (26.4%) and in flat bones (25%). The localization was mainly in the bone methaphyses (56.6%). On pathological examination, primary ABC was diagnosed in 65.3% of cases, secondary ABC in 23.6%, ABC and concomitant osteitis in 7%, ABC and giant cell tumor in 2.7%, ABC and chondrosarcoma in 1.4%. The application of four methods resulted in 72.2% consistency between diagnostic imaging and pathological examination. In case of only one method used the consistency was 75% for MRI, 63% for CT, 55.4% for plain films and 50% for US. In 100% of misdiagnosed cases there were no septa within osteolytic lesions on plain films, whereas in 43.8% features of malignancy were found. In 53% of misdiagnosed cases no fluid levels were observed on CT and in 69% on US. Conclusions: 1. The diagnosis of aneurismal bone cyst based on plain radiography is possible in cases with typical radiological signs. 2. Application of other methods significantly increases the percentage of correct diagnoses. 3. Lack of fluid levels does not exclude the diagnosis of ABC. 4. Imaging features of malignancy do not exclude the diagnosis of ABC

    Skeletal responses to spaceflight

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    The role of gravity in the determination of bone structure is elucidated by observations in adult humans and juvenile animals during spaceflight. The primary response of bone tissue to microgravity is at the interface of the mineral and matrix in the process of biomineralization. This response is manifested by demineralization or retarded growth in some regions of the skeleton and hypermineralization in others. The most pronounced effects are seen in the heelbone and skull, the most distally located bones relative to the heart. Ground based flight simulation models that focus on changes in bone structure at the molecular, organ, and whole body levels are described and compared to flight results. On Earth, the morphologic and compositional changes in the unloaded bones are very similar to changes during flight; however, the ground based changes appear to be more transient. In addition, a redistribution of bone mineral in gravity-dependent bones occurs both in space and during head down positioning on Earth. Longitudinal data provided considerable information on the influence of endocrine and muscular changes on bone structure after unloading

    Segmentation of bone structures in 3D CT images based on continuous max- ow optimization

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    In this paper an algorithm to carry out the automatic segmentation of bone structures in 3D CT images has been implemented. Automatic segmentation of bone structures is of special interest for radiologists and surgeons to analyze bone diseases or to plan some surgical interventions. This task is very complicated as bones usually present intensities overlapping with those of surrounding tissues. This overlapping is mainly due to the composition of bones and to the presence of some diseases such as Osteoarthritis, Osteoporosis, etc. Moreover, segmentation of bone structures is a very time-consuming task due to the 3D essence of the bones. Usually, this segmentation is implemented manually or with algorithms using simple techniques such as thresholding and thus providing bad results. In this paper gray information and 3D statistical information have been combined to be used as input to a continuous max- ow algorithm. Twenty CT images have been tested and di erent coe cients have been computed to assess the performance of our implementation. Dice and Sensitivity values above 0.91 and 0.97 respectively were obtained. A comparison with Level Sets and thresholding techniques has been carried out and our results outperformed them in terms of accuracy.Ministerio de ciencia e innovación TEC2010-21619-C04-02Junta de Andalucía P11-TIC-772

    Early evidence of stone tool use in bone working activities at Qesem Cave, Israel

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    For a long while, the controversy surrounding several bone tools coming from pre-Upper Palaeolithic contexts favoured the view of Homo sapiens as the only species of the genus Homo capable of modifying animal bones into specialised tools. However, evidence such as South African Early Stone Age modified bones, European Lower Palaeolithic flaked bone tools, along with Middle and Late Pleistocene bone retouchers, led to a re-evaluation of the conception of Homo sapiens as the exclusive manufacturer of specialised bone tools. The evidence presented herein include use wear and bone residues identified on two flint scrapers as well as a sawing mark on a fallow deer tibia, not associated with butchering activities. Dated to more than 300 kya, the evidence here presented is among the earliest related to tool-assisted bone working intended for non-dietary purposes, and contributes to the debate over the recognition of bone working as a much older behaviour than previously thought. The results of this study come from the application of a combined methodological approach, comprising use wear analysis, residue analysis, and taphonomy. This approach allowed for the retrieval of both direct and indirect evidence of tool-assisted bone working, at the Lower Palaeolithic site of Qesem Cave (Israel)
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