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Sample records for high-resolution temporal bone

  1. Integration of High-resolution Data for Temporal Bone Surgical Simulations

    PubMed Central

    Wiet, Gregory J.; Stredney, Don; Powell, Kimerly; Hittle, Brad; Kerwin, Thomas

    2016-01-01

    Purpose To report on the state of the art in obtaining high-resolution 3D data of the microanatomy of the temporal bone and to process that data for integration into a surgical simulator. Specifically, we report on our experience in this area and discuss the issues involved to further the field. Data Sources Current temporal bone image acquisition and image processing established in the literature as well as in house methodological development. Review Methods We reviewed the current English literature for the techniques used in computer-based temporal bone simulation systems to obtain and process anatomical data for use within the simulation. Search terms included “temporal bone simulation, surgical simulation, temporal bone.” Articles were chosen and reviewed that directly addressed data acquisition and processing/segmentation and enhancement with emphasis given to computer based systems. We present the results from this review in relationship to our approach. Conclusions High-resolution CT imaging (≤100μm voxel resolution), along with unique image processing and rendering algorithms, and structure specific enhancement are needed for high-level training and assessment using temporal bone surgical simulators. Higher resolution clinical scanning and automated processes that run in efficient time frames are needed before these systems can routinely support pre-surgical planning. Additionally, protocols such as that provided in this manuscript need to be disseminated to increase the number and variety of virtual temporal bones available for training and performance assessment. PMID:26762105

  2. The Prevalence of Persistent Petrosquamosal Sinus and Other Temporal Bone Anatomical Variations on High-Resolution Temporal Bone Computed Tomography

    PubMed Central

    Bożek, Paweł; Kluczewska, Ewa; Misiołek, Maciej; Ścierski, Wojciech; Lisowska, Grażyna

    2016-01-01

    Background The aim of the study was to determine the prevalence of petrosquamosal sinus (PSS) and other temporal bone (TB) anatomical variations in various patients using high-resolution computed tomography (CT). Material/Methods We reviewed clinical and consecutively obtained CT data for 276 TBs of 138 patients. The incidence of TB anatomical variations was compared among patients with radiological markers of chronic otitis media (RCOM) and non-RCOM. Results The PSS incidence in our sample was 6.9%, and it was significantly higher in TBs with RCOM (14.6%). Selected anatomical variations of RCOM TBs were observed: lateral sigmoid sinus (14.5%), prominent sigmoid sinus (23.6%), PSS (14.6%), and high jugular bulb (17.3%). Lateral sigmoid sinus and prominent sigmoid sinus (p<0.01), high jugular bulb (p<0.05), and PSS (p<0.01) were observed more often in RCOM than in non-RCOM TBs. Conclusions The TB vascular and anatomical variations, including PSS, a high jugular bulb, and a laterally and prominent placed sigmoid sinus, were more often observed in TBs with RCOM. Presurgical imaging and CT-based navigation techniques for TB surgery can offer remarkable value for understanding the altered anatomy of this complex structure and can localize rare anatomical variations. PMID:27811834

  3. Temporal Bone CT: Improved Image Quality and Potential for Decreased Radiation Dose Using an Ultra-High-Resolution Scan Mode with an Iterative Reconstruction Algorithm.

    PubMed

    Leng, S; Diehn, F E; Lane, J I; Koeller, K K; Witte, R J; Carter, R E; McCollough, C H

    2015-09-01

    Radiation dose in temporal bone CT imaging can be high due to the requirement of high spatial resolution. In this study, we assessed whether CT imaging of the temporal bone by using an ultra-high-resolution scan mode combined with iterative reconstruction provides higher spatial resolution and lower image noise than a z-axis ultra-high-resolution mode. Patients with baseline temporal bone CT scans acquired by using a z-axis ultra-high-resolution protocol and a follow-up scan by using the ultra-high-resolution-iterative reconstruction technique were identified. Images of left and right temporal bones were reconstructed in the axial, coronal, and Poschl planes. Three neuroradiologists assessed the spatial resolution of the following structures: round and oval windows, incudomallear and incudostapedial joints, basal turn spiral lamina, and scutum. The paired z-axis ultra-high-resolution and ultra-high-resolution-iterative reconstruction images were displayed side by side in random order, with readers blinded to the imaging protocol. Image noise was compared in ROIs over the posterior fossa. We identified 8 patients, yielding 16 sets of temporal bone images (left and right). Three sets were excluded because the patient underwent surgery between the 2 examinations. Spatial resolution was comparable (Poschl) or slightly better (axial and coronal planes) with ultra-high-resolution-iterative reconstruction than with z-axis ultra-high-resolution. A paired t test indicated that noise was significantly lower with ultra-high-resolution-iterative reconstruction than with z-axis ultra-high-resolution (P < .001), with a mean noise reduction of 37% (range, 18%-49%). The ultra-high-resolution-iterative reconstruction scan mode has similar or slightly better resolution relative to the z-axis ultra-high-resolution mode for CT of the temporal bone but significantly (P < .01) lower image noise, which may enable the dose to be reduced by approximately 50%. © 2015 by American Journal of

  4. Initial results of a new generation dual source CT system using only an in-plane comb filter for ultra-high resolution temporal bone imaging.

    PubMed

    Meyer, Mathias; Haubenreisser, Holger; Raupach, Rainer; Schmidt, Bernhard; Lietzmann, Florian; Leidecker, Christianne; Allmendinger, Thomas; Flohr, Thomas; Schad, Lothar R; Schoenberg, Stefan O; Henzler, Thomas

    2015-01-01

    To prospectively evaluate radiation dose and image quality of a third generation dual-source CT (DSCT) without z-axis filter behind the patient for temporal bone CT. Forty-five patients were either examined on a first, second, or third generation DSCT in an ultra-high-resolution (UHR) temporal bone-imaging mode. On the third generation DSCT system, the tighter focal spot of 0.2 mm(2) removes the necessity for an additional z-axis-filter, leading to an improved z-axis radiation dose efficiency. Images of 0.4 mm were reconstructed using standard filtered-back-projection or iterative reconstruction (IR) technique for previous generations of DSCT and a novel IR algorithm for the third generation DSCT. Radiation dose and image quality were compared between the three DSCT systems. The statistically significantly highest subjective and objective image quality was evaluated for the third generation DSCT when compared to the first or second generation DSCT systems (all p < 0.05). Total effective dose was 63%/39% lower for the third generation examination as compared to the first and second generation DSCT. Temporal bone imaging without z-axis-UHR-filter and a novel third generation IR algorithm allows for significantly higher image quality while lowering effective dose when compared to the first two generations of DSCTs. • Omitting the z-axis-filter allows a reduction in radiation dose of 50% • A smaller focal spot of 0.2 mm (2) significantly improves spatial resolution • Ultra-high-resolution temporal-bone-CT helps to gain diagnostic information of the middle/inner ear.

  5. High resolution films for bone regeneration evaluation.

    PubMed

    Jammal, María V; Territoriale, Erika B; Abate, Carlos M; Missana, Liliana R

    2010-01-01

    Diagnostic imaging techniques (DIxT) seem to be a useful tool for evaluating bone formation in both human and animal models. There is little evidence on the use of Soft X-Rays (sXR) with high-resolution films for studying the healing process in critical bone size defects (CSD). The aim of this study was to evaluate the ability of soft X-Ray - High Resolution Films (sXR) to distinguish bone regeneration in CSDs. A CSD was created in each of 16 Wistar rat calvariae. The animals were euthanized at 1, 3 and 6 weeks after surgery. The samples were submitted to cXR (conventional X-rays), sXR techniques and histological procedures (HP). Bone formation was observed at CSD edges at all periods of time. At 6 week there was also new bone in the central area. The CSD was not fully regenerated after any period of time. Histometric results were 0.16%; 0.75% and 0.89% new bone formed at weeks 1, 3 and 6 respectively; radiometric results at cXR were 0% in all samples. Evaluation of sXR shows 0.4%; 0.50% and 3.64% bone at weeks 1, 3 and 6. Mean and Standard Deviation were calculated. The data were submitted to statistical analysis using the Pearson product-moment correlation coefficient test. The r value was 0.581. Under these experimental conditions, sXR was found to be a suitable method for detecting new bone formation, based on the positive correlation between sXR and HP during the bone healing process of CSDs in rat calvaria. Furthermore, the sXR technique allowed us to obtain samples with appropriate spatial orientation.

  6. Topological Data Analysis of High-Resolution Temporal Rainfall

    NASA Astrophysics Data System (ADS)

    Carsteanu, Alin Andrei; Fernández Méndez, Félix; Vásquez Aguilar, Raciel

    2017-04-01

    This study applies topological data analysis (TDA) to the state space representations of high-resolution temporal rainfall intensity data from Iowa City (IIHR, U of Iowa). Using a sufficient embedding dimension, topological properties of the underlying manifold are depicted.

  7. High resolution bone mineral densitometry with a gamma camera

    NASA Technical Reports Server (NTRS)

    Leblanc, A.; Evans, H.; Jhingran, S.; Johnson, P.

    1983-01-01

    A technique by which the regional distribution of bone mineral can be determined in bone samples from small animals is described. The technique employs an Anger camera interfaced to a medical computer. High resolution imaging is possible by producing magnified images of the bone samples. Regional densitometry of femurs from oophorectomised and bone mineral loss.

  8. Persistence Diagrams of High-Resolution Temporal Rainfall

    NASA Astrophysics Data System (ADS)

    Fernández Méndez, F.; Carsteanu, A. A.

    2015-12-01

    This study applies Topological Data Analysis (TDA), by generating persistence diagrams to uncover patterns in the data of high-resolution temporal rainfall intensities from Iowa City (IIHR, U of Iowa). Persistence diagrams are a way to identify essential cycles in state-space representations of the data.

  9. Homology Groups of High-Resolution Temporal Rainfall

    NASA Astrophysics Data System (ADS)

    Vásquez Aguilar, R.; Carsteanu, A. A.

    2015-12-01

    Using high-resolution temporal rainfall intensities from Iowa City, IA (IIHR, U of Iowa), we perform an analysis of the homology groups generated by data connectivity in state space, and attempt a qualitative interpretation of the first and second homology groups. Let us note that homology groups are generated, in the context of topological data analysis (TDA), by representing the data in n-dimensional state space and building a connectivity diagram according to the respective distances between the data points. Subsequently, the topological invariants of the resulting connected structures are being analyzed.

  10. High resolution temporal rainfall data generation for climate change studies

    NASA Astrophysics Data System (ADS)

    Rehan Anis, Muhammad; Rode, Michael

    2010-05-01

    The lack of temporal high-resolution rainfall data is one of the most prominent limiting factors in hydrological and water quality simulations. Most climate change models predict that precipitation patterns will change and that extreme meteorological events are likely to occur more frequently. For climate change studies future climate scenarios are needed which are generally available on daily or six hourly time step. Fine timescale rainfall data of at least 30 minute is required for soil erosion and sediment transport calculations. However, such data are not available for future climate conditions. Therefore it is necessary to develop a disaggregation procedure which is applicable for a wide range of daily and hourly rainfall data. This study evaluates the generation of high-resolution rainfall data at a point location. We use the coupling of the Hyetos and Cascade approach to disaggregate the daily rainfall data up to 10 minute rainfall intensities. In this study we developed a criteria by dividing the daily rainfall data into four different categories according to their magnitude, i.e. 1-10 mm, 11-25 mm, 26-50 mm and 51-above mm and disaggregate each category according to the following three steps: (1) calculating the Bartlett-Lewis Rectangular Pulse Parameter (BLRP) from historical data, (2) disaggregate the future statistically downscaled data (WETTREG Model) using historical BLRP parameters and Hyetos disaggregation model (disaggregate from daily to hourly); and (3) further disaggregation of hourly data into sub-hourly up to 10 minute rainfall intensity using random multiplicative cascade approach. The combination of two models, Hyetos and Cascade approach are successfully applied on the complete range of precipitation. We tested this technique on summer and winter precipitation on different amounts for selected stations with varying elevations to cover a range of rainfall pattern. Dividing the rainfall amount into magnitude categories gives us good result

  11. Temporal bone meningiomas.

    PubMed

    Hooper, R; Siu, K; Cousins, V

    1990-10-01

    Meningiomas should be considered in the differential diagnosis of space-occupying lesions of the temporal bone. Five cases of meningiomas of the temporal bone are described and the literature reviewed. These tumours may stimulate Schwannomas and glomus tumours in their presentation and radiological findings. The tumours were managed by combining standard neurosurgical approaches with temporal bone and skull base techniques.

  12. High resolution autofocus for spatial temporal biomedical research

    NASA Astrophysics Data System (ADS)

    Li, Sihong; Cui, Xiaodong; Huang, Wei

    2013-11-01

    Maintaining focus has been a critical but challenging issue in optical microscopy, particularly for microscopic imaging systems currently used in biomedical research. During live cell imaging, environmental temperature fluctuations and other factors contribute to the unavoidable focus drift. For single molecular imaging and super resolution, focus drift can be significant even over short durations. The current commercial and experimental solutions are either optically complicated, expensive, or with limited axial resolution. Here, we present a simple autofocus solution based on low cost solid state laser and imaging sensor. By improving the optical train design and using real-time data analysis, improvement in axial resolution by approximately two orders of magnitudes over the focal depth of microscope objectives can be achieved. This solution has been tested for prolonged live cell imaging for fast ramping up in environmental chamber temperature and large daily swing in room temperature. In addition, this system can be used to spatial-temporally measure the surface for three-dimensional cell culture and tissue engineering, with flexibility that exceeds commercially available systems.

  13. High-resolution bone imaging for osteoporosis diagnostics and therapy monitoring using clinical MDCT and MRI.

    PubMed

    Baum, T; Karampinos, D C; Liebl, H; Rummeny, E J; Waldt, S; Bauer, J S

    2013-01-01

    Osteoporosis is classified as a public health problem due to its increased risk for fragility fractures. Osteoporotic fractures, in particular spine and hip fractures, are associated with a high morbidity and mortality, and generate immense financial cost. The World Health Organisation (WHO) based the diagnosis of osteoporosis on the measurement of bone mineral density (BMD) using dual-energy X-ray absorptiometry (DXA). However, BMD values of subjects with versus without osteoporotic fractures overlap. Furthermore, it was reported that the anti-fracture effects of drugs could be only partially explained by their effects on BMD. Bone strength reflects the integration of BMD and bone quality. The later can be partly determined by measurements of bone microstructure. Therefore, substantial research efforts have been undertaken to assess bone microstructure by using high-resolution imaging techniques, including high-resolution peripheral quantitative computed tomography (hr-pQCT), high-resolution multi-detector computed tomography (MDCT), and high-resolution magnetic resonance imaging (MRI). Clinical MDCT and MRI systems are broadly available and allow an adequate depiction of the bone microstructure at the clinically most important fracture sites, i.e. radius, spine and hip. Bone microstructure parameters and finite element models can be computed in high-resolution MDCT and MR images. These measurements improved the prediction of bone strength beyond the DXA-derived BMD and revealed pharmacotherapy effects, which are partly not captured by BMD. Therefore, high-resolution bone imaging using clinical MDCT and MRI may be beneficial for osteoporosis diagnostics and allow a highly sensitive monitoring of drug treatment, which plays an important role in the prevention of fragility fractures.

  14. Object Manifold Alignment for Multi-Temporal High Resolution Remote Sensing Images Classification

    NASA Astrophysics Data System (ADS)

    Gao, G.; Zhang, M.; Gu, Y.

    2017-05-01

    Multi-temporal remote sensing images classification is very useful for monitoring the land cover changes. Traditional approaches in this field mainly face to limited labelled samples and spectral drift of image information. With spatial resolution improvement, "pepper and salt" appears and classification results will be effected when the pixelwise classification algorithms are applied to high-resolution satellite images, in which the spatial relationship among the pixels is ignored. For classifying the multi-temporal high resolution images with limited labelled samples, spectral drift and "pepper and salt" problem, an object-based manifold alignment method is proposed. Firstly, multi-temporal multispectral images are cut to superpixels by simple linear iterative clustering (SLIC) respectively. Secondly, some features obtained from superpixels are formed as vector. Thirdly, a majority voting manifold alignment method aiming at solving high resolution problem is proposed and mapping the vector data to alignment space. At last, all the data in the alignment space are classified by using KNN method. Multi-temporal images from different areas or the same area are both considered in this paper. In the experiments, 2 groups of multi-temporal HR images collected by China GF1 and GF2 satellites are used for performance evaluation. Experimental results indicate that the proposed method not only has significantly outperforms than traditional domain adaptation methods in classification accuracy, but also effectively overcome the problem of "pepper and salt".

  15. Congenital malformations of the temporal bone.

    PubMed

    Mukerji, Shraddha S; Parmar, Hemant A; Ibrahim, Mohannad; Mukherji, Suresh K

    2011-08-01

    Congenital ear or temporal bone malformations are a diagnostic challenge to radiologists and surgeons alike. Newer imaging techniques can detect subtle changes in middle ear and cochlear anatomy. This information is invaluable with increasing use of hearing restoration surgeries and/or cochlear implants in such patients. This article discusses the embryogenesis, classification system, and salient imaging findings of congenital outer, middle ear, and inner ear anomalies in children. Both high-resolution computerized tomography and magnetic resonance imaging scans of the temporal bones are described.

  16. Clinical use of high-resolution ultrasonography for the diagnosis of type II accessory navicular bone.

    PubMed

    Chuang, Yi-Wen; Tsai, Wen-San; Chen, Kai-Hua; Hsu, Hung-Chih

    2012-02-01

    Medial foot pain is a common complaint in rehabilitation clinics. The differential diagnoses include many musculoskeletal disorders like tendonitis and inflammation of ossicles. Posterior tibialis tendonitis is a common cause of foot pain in adults. The accessory navicular (AN) bone is occasionally observed and considered as a secondary ossification center of the navicular bone. Occasionally, posterior tibialis tendonitis and AN bone may cause acute or chronic medial foot pain with varying degrees of dysfunction. Previously, the diagnosis of an AN bone in a painful medial foot was based on clinical presentation and radiographic examinations such as plain radiography, bone scintigraphy, and magnetic resonance imaging. However, the application of soft-tissue ultrasonography for the diagnosis of posterior tibialis tendonitis associated with an AN bone has not been documented. Here, we report the case of a 60-yr-old woman with painful medial foot which had a diagnosis of posterior tibialis tendonitis associated with an AN bone by high-resolution ultrasonography.

  17. Imaging of the temporal bone.

    PubMed

    Abele, Travis A; Wiggins, Richard H

    2015-01-01

    A variety of congenital, infectious, inflammatory, vascular, and benign and malignant neoplastic pathology affects the temporal bone. Knowledge of normal temporal bone anatomy and space-specific differential diagnoses is key to imaging interpretation of temporal bone. Correlation with clinical history and physical examination is vital to making the correct diagnosis or providing an appropriate differential. Computed tomography and magnetic resonance imaging are complementary imaging modalities in the evaluation of temporal bone abnormalities.

  18. Feasibility of fabricating personalized 3D-printed bone grafts guided by high-resolution imaging

    NASA Astrophysics Data System (ADS)

    Hong, Abigail L.; Newman, Benjamin T.; Khalid, Arbab; Teter, Olivia M.; Kobe, Elizabeth A.; Shukurova, Malika; Shinde, Rohit; Sipzner, Daniel; Pignolo, Robert J.; Udupa, Jayaram K.; Rajapakse, Chamith S.

    2017-03-01

    Current methods of bone graft treatment for critical size bone defects can give way to several clinical complications such as limited available bone for autografts, non-matching bone structure, lack of strength which can compromise a patient's skeletal system, and sterilization processes that can prevent osteogenesis in the case of allografts. We intend to overcome these disadvantages by generating a patient-specific 3D printed bone graft guided by high-resolution medical imaging. Our synthetic model allows us to customize the graft for the patients' macro- and microstructure and correct any structural deficiencies in the re-meshing process. These 3D-printed models can presumptively serve as the scaffolding for human mesenchymal stem cell (hMSC) engraftment in order to facilitate bone growth. We performed highresolution CT imaging of a cadaveric human proximal femur at 0.030-mm isotropic voxels. We used these images to generate a 3D computer model that mimics bone geometry from micro to macro scale represented by STereoLithography (STL) format. These models were then reformatted to a format that can be interpreted by the 3D printer. To assess how much of the microstructure was replicated, 3D-printed models were re-imaged using micro-CT at 0.025-mm isotropic voxels and compared to original high-resolution CT images used to generate the 3D model in 32 sub-regions. We found a strong correlation between 3D-printed bone volume and volume of bone in the original images used for 3D printing (R2 = 0.97). We expect to further refine our approach with additional testing to create a viable synthetic bone graft with clinical functionality.

  19. High Resolution Peripheral Quantitative Computed Tomography for Assessment of Bone Quality

    NASA Astrophysics Data System (ADS)

    Kazakia, Galateia

    2014-03-01

    The study of bone quality is motivated by the high morbidity, mortality, and societal cost of skeletal fractures. Over 10 million people are diagnosed with osteoporosis in the US alone, suffering 1.5 million osteoporotic fractures and costing the health care system over 17 billion annually. Accurate assessment of fracture risk is necessary to ensure that pharmacological and other interventions are appropriately administered. Currently, areal bone mineral density (aBMD) based on 2D dual-energy X-ray absorptiometry (DXA) is used to determine osteoporotic status and predict fracture risk. Though aBMD is a significant predictor of fracture risk, it does not completely explain bone strength or fracture incidence. The major limitation of aBMD is the lack of 3D information, which is necessary to distinguish between cortical and trabecular bone and to quantify bone geometry and microarchitecture. High resolution peripheral quantitative computed tomography (HR-pQCT) enables in vivo assessment of volumetric BMD within specific bone compartments as well as quantification of geometric and microarchitectural measures of bone quality. HR-pQCT studies have documented that trabecular bone microstructure alterations are associated with fracture risk independent of aBMD.... Cortical bone microstructure - specifically porosity - is a major determinant of strength, stiffness, and fracture toughness of cortical tissue and may further explain the aBMD-independent effect of age on bone fragility and fracture risk. The application of finite element analysis (FEA) to HR-pQCT data permits estimation of patient-specific bone strength, shown to be associated with fracture incidence independent of aBMD. This talk will describe the HR-pQCT scanner, established metrics of bone quality derived from HR-pQCT data, and novel analyses of bone quality currently in development. Cross-sectional and longitudinal HR-pQCT studies investigating the impact of aging, disease, injury, gender, race, and

  20. Visualizing the root-PDL-bone interface using high-resolution microtomography

    NASA Astrophysics Data System (ADS)

    Dalstra, Michel; Cattaneo, Paolo M.; Herzen, Julia; Beckmann, Felix

    2008-08-01

    The root/periodontal ligament/bone (RPB) interface is important for a correct understanding of the load transfer mechanism of masticatory forces and orthodontic loads. It is the aim of this study to assess the three-dimensional structure of the RPB interface using high-resolution microtomography. A human posterior jaw segment, obtained at autopsy from a 22-year old male donor was first scanned using a tomograph at the HASYLAB/DESY synchrotron facility (Hamburg, Germany) at 31μm resolution. Afterwards the first molar and its surrounding bone were removed with a 10mm hollow core drill. From this cylindrical sample smaller samples were drilled out in the buccolingual direction with a 1.5mm hollow core drill. These samples were scanned at 4μm resolution. The scans of the entire segment showed alveolar bone with a thin lamina dura, supported by an intricate trabecular network. Although featuring numerous openings between the PDL and the bone marrow on the other side to allow blood vessels to transverse, the lamina dura seems smooth at this resolution. First at high resolution, however, it becomes evident that it is irregular with bony spiculae and pitted surfaces. Therefore the stresses in the bone during physiological or orthodontic loading are much higher than expected from a smooth continuous alveolus.

  1. [High resolution peripheral quantitative computed tomography for the assessment of morphological and mechanical bone parameters].

    PubMed

    Fuller, Henrique; Fuller, Ricardo; Pereira, Rosa Maria R

    2015-01-01

    High resolution peripheral quantitative computed tomography (HR-pQCT) is a new technology commercially available for less than 10 years that allows performing in vivo assessment of bone parameters. HR-pQCT assesses the trabecular thickness, trabecular separation, trabecular number and connectivity density and, in addition, cortical bone density and thickness and total bone volume and density in high-definition mode, which additionally allows obtaining digital constructs of bone microarchitecture. The application of mathematics to captured data, a method called finite element analysis (FEA), allows the estimation of the physical properties of the tissue, simulating supported loads in a non-invasive way. Thus, HR-pQCT simultaneously acquires data previously provided separately by dual energy x-ray absorptiometry (DXA), magnetic resonance imaging and histomorphometry, aggregating biomechanical estimates previously only possible in extracted tissues. This method has a satisfactory reproducibility, with coefficients of variation rarely exceeding 3%. Regarding accuracy, the method shows a fair to good agreement (r(2) = 0.37-0.97). The main clinical application of this method is in the quantification and monitoring of metabolic bone disorders, more fully evaluating bone strength and fracture risk. In rheumatoid arthritis patients, this allows gauging the number and size of erosions and cysts, in addition to joint space. In osteoarthritis, it is possible to characterize the bone marrow edema-like areas that show a correlation with cartilage breakdown. Given its high cost, HR-pQCT is still a research tool, but the high resolution and efficiency of this method reveal advantages over the methods currently used for bone assessment, with a potential to become an important tool in clinical practice.

  2. A new high-resolution computed tomography (CT) segmentation method for trabecular bone architectural analysis.

    PubMed

    Scherf, Heike; Tilgner, Rico

    2009-09-01

    In the last decade, high-resolution computed tomography (CT) and microcomputed tomography (micro-CT) have been increasingly used in anthropological studies and as a complement to traditional histological techniques. This is due in large part to the ability of CT techniques to nondestructively extract three-dimensional representations of bone structures. Despite prior studies employing CT techniques, no completely reliable method of bone segmentation has been established. Accurate preprocessing of digital data is crucial for measurement accuracy, especially when subtle structures such as trabecular bone are investigated. The research presented here is a new, reproducible, accurate, and fully automated computerized segmentation method for high-resolution CT datasets of fossil and recent cancellous bone: the Ray Casting Algorithm (RCA). We compare this technique with commonly used methods of image thresholding (i.e., the half-maximum height protocol and the automatic, adaptive iterative thresholding procedure). While the quality of the input images is crucial for conventional image segmentation, the RCA method is robust regarding the signal to noise ratio, beam hardening, ring artifacts, and blurriness. Tests with data of extant and fossil material demonstrate the superior quality of RCA compared with conventional thresholding procedures, and emphasize the need for careful consideration of optimal CT scanning parameters.

  3. Review of congenital inner ear abnormalities on CT temporal bone.

    PubMed

    Yiin, R S Z; Tang, P H; Tan, T Y

    2011-09-01

    The aetiology of profound hearing loss in children is complex and multifactorial. Congenital inner ear abnormality is a major cause of hearing loss in children. CT temporal bone imaging is the modality of choice in the investigation of hearing loss. Recognising the congenital abnormalities of the inner ear guides the clinician's management of the condition. This pictorial essay illustrates the congenital abnormalities of the inner ear on high resolution CT temporal bone images and correlation with developmental arrest during embryology.

  4. Accuracy of high-resolution peripheral quantitative computed tomography for measurement of bone quality.

    PubMed

    MacNeil, Joshua A; Boyd, Steven K

    2007-12-01

    The introduction of three-dimensional high-resolution peripheral in vivo quantitative computed tomography (HR-pQCT) (XtremeCT, Scanco Medical, Switzerland; voxel size 82 microm) provides a new approach to monitor micro-architectural bone changes longitudinally. The accuracy of HR-pQCT for three important determinants of bone quality, including bone mineral density (BMD), architectural measurements and bone mechanics, was determined through a comparison with micro-computed tomography (microCT) and dual energy X-ray absorptiometry (DXA). Forty measurements from 10 cadaver radii with low bone mass were scanned using the three modalities, and image registration was used for 3D data to ensure identical regions were analyzed. The areal BMD of DXA correlated well with volumetric BMD by HR-pQCT despite differences in dimensionality (R(2) = 0.69), and the correlation improved when non-dimensional bone mineral content was assessed (R(2) = 0.80). Morphological parameters measured by HR-pQCT in a standard patient analysis, including bone volume ratio, trabecular number, derived trabecular thickness, derived trabecular separation, and cortical thickness correlated well with muCT measures (R(2) = 0.59-0.96). Additionally, some non-metric parameters such as connectivity density (R(2) = 0.90) performed well. The mechanical stiffness assessed by finite element analysis of HR-pQCT images was generally higher than for microCT data due to resolution differences, and correlated well at the continuum level (R(2) = 0.73). The validation here of HR-pQCT against gold-standards microCT and DXA provides insight into the accuracy of the system, and suggests that in addition to the standard patient protocol, additional indices of bone quality including connectivity density and mechanical stiffness may be appropriate to include as part of a standard patient analysis for clinical monitoring of bone quality.

  5. A hyper-temporal remote sensing protocol for high-resolution mapping of ecological sites

    PubMed Central

    Karl, Jason W.

    2017-01-01

    sites) spectral variability through time, 2) field sampling protocols that accurately characterize key soil properties (e.g., texture, depth) need to be adopted, and 3) additional environmental covariates (e.g. terrain attributes) need to be evaluated that may help further differentiate sites with similar spectral signals. Finally, the proposed hyper-temporal remote sensing framework may provide a standardized approach to evaluate and test our ecological site concepts through examining differences in vegetation dynamics in response to climatic variability and other drivers of land-use change. Results from this study demonstrate the efficacy of the hyper-temporal remote sensing approach for high resolution mapping of ecological sites, and highlights its utility in terms of reduced cost and time investment relative to traditional manual mapping approaches. PMID:28414731

  6. A hyper-temporal remote sensing protocol for high-resolution mapping of ecological sites.

    PubMed

    Maynard, Jonathan J; Karl, Jason W

    2017-01-01

    ) spectral variability through time, 2) field sampling protocols that accurately characterize key soil properties (e.g., texture, depth) need to be adopted, and 3) additional environmental covariates (e.g. terrain attributes) need to be evaluated that may help further differentiate sites with similar spectral signals. Finally, the proposed hyper-temporal remote sensing framework may provide a standardized approach to evaluate and test our ecological site concepts through examining differences in vegetation dynamics in response to climatic variability and other drivers of land-use change. Results from this study demonstrate the efficacy of the hyper-temporal remote sensing approach for high resolution mapping of ecological sites, and highlights its utility in terms of reduced cost and time investment relative to traditional manual mapping approaches.

  7. High Resolution Spatial and Temporal Mapping of Traffic-Related Air Pollutants

    PubMed Central

    Batterman, Stuart; Ganguly, Rajiv; Harbin, Paul

    2015-01-01

    Vehicle traffic is one of the most significant emission sources of air pollutants in urban areas. While the influence of mobile source emissions is felt throughout an urban area, concentrations from mobile emissions can be highest near major roadways. At present, information regarding the spatial and temporal patterns and the share of pollution attributable to traffic-related air pollutants is limited, in part due to concentrations that fall sharply with distance from roadways, as well as the few monitoring sites available in cities. This study uses a newly developed dispersion model (RLINE) and a spatially and temporally resolved emissions inventory to predict hourly PM2.5 and NOx concentrations across Detroit (MI, USA) at very high spatial resolution. Results for annual averages and high pollution days show contrasting patterns, the need for spatially resolved analyses, and the limitations of surrogate metrics like proximity or distance to roads. Data requirements, computational and modeling issues are discussed. High resolution pollutant data enable the identification of pollutant “hotspots”, “project-level” analyses of transportation options, development of exposure measures for epidemiology studies, delineation of vulnerable and susceptible populations, policy analyses examining risks and benefits of mitigation options, and the development of sustainability indicators integrating environmental, social, economic and health information. PMID:25837345

  8. Large-scale, high-resolution neurophysiological maps underlying FMRI of macaque temporal lobe.

    PubMed

    Issa, Elias B; Papanastassiou, Alex M; DiCarlo, James J

    2013-09-18

    Maps obtained by functional magnetic resonance imaging (fMRI) are thought to reflect the underlying spatial layout of neural activity. However, previous studies have not been able to directly compare fMRI maps to high-resolution neurophysiological maps, particularly in higher level visual areas. Here, we used a novel stereo microfocal x-ray system to localize thousands of neural recordings across monkey inferior temporal cortex (IT), construct large-scale maps of neuronal object selectivity at subvoxel resolution, and compare those neurophysiology maps with fMRI maps from the same subjects. While neurophysiology maps contained reliable structure at the sub-millimeter scale, fMRI maps of object selectivity contained information at larger scales (>2.5 mm) and were only partly correlated with raw neurophysiology maps collected in the same subjects. However, spatial smoothing of neurophysiology maps more than doubled that correlation, while a variety of alternative transforms led to no significant improvement. Furthermore, raw spiking signals, once spatially smoothed, were as predictive of fMRI maps as local field potential signals. Thus, fMRI of the inferior temporal lobe reflects a spatially low-passed version of neurophysiology signals. These findings strongly validate the widespread use of fMRI for detecting large (>2.5 mm) neuronal domains of object selectivity but show that a complete understanding of even the most pure domains (e.g., faces vs nonface objects) requires investigation at fine scales that can currently only be obtained with invasive neurophysiological methods.

  9. Multi-temporal database of High Resolution Stereo Camera (HRSC) images

    NASA Astrophysics Data System (ADS)

    Erkeling, G.; Luesebrink, D.; Hiesinger, H.; Reiss, D.

    2013-09-01

    Image data transmitted to Earth by Martian spacecraft since the 1970s, for example by Mariner and Viking, Mars Global Surveyor (MGS), Mars Express (MEx) and the Mars Reconnaissance Orbiter (MRO) showed, that the surface of Mars has changed dramatically and actually is continually changing [e.g., 1-8]. The changes are attributed to a large variety of atmospherical, geological and morphological processes, including eolian processes [9,10], mass wasting processes [11], changes of the polar caps [12] and impact cratering processes [13]. In addition, comparisons between Mariner, Viking and Mars Global Surveyor images suggest that more than one third of the Martian surface has brightened or darkened by at least 10% [6]. Albedo changes can have effects on the global heat balance and the circulation of winds, which can result in further surface changes [14-15]. In particular, the High Resolution Stereo Camera (HRSC) [16,17] on board Mars Express (MEx) covers large areas at high resolution and is therefore suited to detect the frequency, extent and origin of Martian surface changes. Since 2003 HRSC acquires high-resolution images of the Martian surface and contributes to Martian research, with focus on the surface morphology, the geology and mineralogy, the role of liquid water on the surface and in the atmosphere, on volcanism, as well as on the proposed climate change throughout the Martian history and has improved our understanding of the evolution of Mars significantly [18-21]. The HRSC data are available at ESA's Planetary Science Archive (PSA) as well as through the NASA Planetary Data System (PDS). Both data platforms are frequently used by the scientific community and provide additional software and environments to further generate map-projected and geometrically calibrated HRSC data. However, while previews of the images are available, there is no possibility to quickly and conveniently see the spatial and temporal availability of HRSC images in a specific region

  10. Multi-temporal database of High Resolution Stereo Camera (HRSC) images - Alpha version

    NASA Astrophysics Data System (ADS)

    Erkeling, G.; Luesebrink, D.; Hiesinger, H.; Reiss, D.; Jaumann, R.

    2014-04-01

    Image data transmitted to Earth by Martian spacecraft since the 1970s, for example by Mariner and Viking, Mars Global Surveyor (MGS), Mars Express (MEx) and the Mars Reconnaissance Orbiter (MRO) showed, that the surface of Mars has changed dramatically and actually is continually changing [e.g., 1-8]. The changes are attributed to a large variety of atmospherical, geological and morphological processes, including eolian processes [9,10], mass wasting processes [11], changes of the polar caps [12] and impact cratering processes [13]. In addition, comparisons between Mariner, Viking and Mars Global Surveyor images suggest that more than one third of the Martian surface has brightened or darkened by at least 10% [6]. Albedo changes can have effects on the global heat balance and the circulation of winds, which can result in further surface changes [14-15]. The High Resolution Stereo Camera (HRSC) [16,17] on board Mars Express (MEx) covers large areas at high resolution and is therefore suited to detect the frequency, extent and origin of Martian surface changes. Since 2003 HRSC acquires highresolution images of the Martian surface and contributes to Martian research, with focus on the surface morphology, the geology and mineralogy, the role of liquid water on the surface and in the atmosphere, on volcanism, as well as on the proposed climate change throughout the Martian history and has improved our understanding of the evolution of Mars significantly [18-21]. The HRSC data are available at ESA's Planetary Science Archive (PSA) as well as through the NASA Planetary Data System (PDS). Both data platforms are frequently used by the scientific community and provide additional software and environments to further generate map-projected and geometrically calibrated HRSC data. However, while previews of the images are available, there is no possibility to quickly and conveniently see the spatial and temporal availability of HRSC images in a specific region, which is

  11. High Resolution Satellite Multi-Temporal Interferometry for Landslide and Subsidence Hazard Assessment: An Overview

    NASA Astrophysics Data System (ADS)

    Wasowski, J.; Bovenga, F.; Nitti, D. O.; Nutricato, R.; Chiaradia, M.

    2014-12-01

    The new and planned satellite missions can not only provide global capacity for research-oriented and practical applications such as mapping, characterizing and monitoring of areas affected by slope and subsidence hazards, but also offer a possibility to push the research frontier and prompt innovative detailed-scale studies on ground movement dynamics and processes. Among a number of emerging space-based remote sensing techniques, synthetic aperture radar (SAR), multi-temporal interferometry (MTI) seems the most promising for important innovation in landslide and subsidence hazards assessment and monitoring. MTI is appealing to those concerned with terrain instability hazards because it can provide very precise information on slow displacements of the ground surface over vast areas with limited vegetation cover. Although MTI techniques are considered to have already reached the operational level, it is apparent that in both research and practice we are at present only beginning to benefit from the high-resolution imagery that is currently acquired by the new generation radar satellites (e.g. COSMO-SkyMed, TerraSAR-X). In this overview we illustrate the great potential of high resolution MTI and explain what this technique can deliver in terms of detection and monitoring of slope and subsidence hazards. This is done by considering different areas characterized by a wide range of geomorphic, climatic and vegetation conditions, and presenting selected case study examples of local to regional scale MTI applications from Europe, China and Haiti. We envision that the current approach to assessment of hazard can be transformed by capitalizing more on the presently underexploited advantage of the MTI technique, i.e. the capability to provide regularly spatially-dense quantitative information for large areas currently unaffected by instabilities, but where the terrain geomorphology and geology may indicate potential for future ground failures.

  12. High Resolution Temporal Normalized Difference Vegetation Indices for Specific Crop Identification

    NASA Astrophysics Data System (ADS)

    Upadhyay, P.; Ghosh, S. K.; Kumar, A.

    2013-05-01

    In many applications of the remote sensing, an user is often interested in identifying specific land cover only while other classes may be of no interest. In the present study, high resolution WorldView-2 image having spatial resolution of 1.84 meter has been used for identifying wheat crop for a test site located in Roorkee, India. WorldView-2 data consists of a total of eight spectral bands out of which last four spectral bands i.e. Red (630-690 nm), Red edge (705-745 nm), NIR 1 (770-895 nm) and NIR 2 (860-1040 nm) are useful for the vegetation related studies. Since Normalized Difference Vegetation Index (NDVI) which is formulated by the Red and NIR band, is well known for vegetation related studies. Therefore, in the present research the above four bands has been used to generate all the four possible combinations of NDVI viz. Red - NIR1, Red edge - NIR 1, Red - NIR 2 and Red edge - NIR 2. Further to study the temporal behaviour of crops, two date WorldView-2 data was taken to make the temporal NDVI. These temporal NDVI were then classified using fuzzy based Possibilistic c-Means (PCM) soft classification. The weighting exponent (or fuzzifier) m was optimized to get the best PCM soft classification output. Wheat crop is represented as the fraction image output of the PCM soft classification corresponding to each temporal NDVI. To check the accuracy of these fraction images, the entropy method was used. The entropy values were calculated for a total of 150 known pixels in each output. It is found that the outputs corresponding to low entropy values have sufficiently high membership values for wheat class, hence these outputs are more accurate. Further, it is observed that the average entropy values found for the temporal NDVI corresponding to the Red - NIR 1, Red edge - NIR 1, Red - NIR 2 and Red edge - NIR 2 are 0.065, 0.089, 0.075 and 0.055 respectively. Thus, it can be concluded that temporal NDVI generated by using a combination of Red edge and NIR-2 bands

  13. Decoding Multiple Sound Categories in the Human Temporal Cortex Using High Resolution fMRI

    PubMed Central

    Zhang, Fengqing; Wang, Ji-Ping; Kim, Jieun; Parrish, Todd; Wong, Patrick C. M.

    2015-01-01

    Perception of sound categories is an important aspect of auditory perception. The extent to which the brain’s representation of sound categories is encoded in specialized subregions or distributed across the auditory cortex remains unclear. Recent studies using multivariate pattern analysis (MVPA) of brain activations have provided important insights into how the brain decodes perceptual information. In the large existing literature on brain decoding using MVPA methods, relatively few studies have been conducted on multi-class categorization in the auditory domain. Here, we investigated the representation and processing of auditory categories within the human temporal cortex using high resolution fMRI and MVPA methods. More importantly, we considered decoding multiple sound categories simultaneously through multi-class support vector machine-recursive feature elimination (MSVM-RFE) as our MVPA tool. Results show that for all classifications the model MSVM-RFE was able to learn the functional relation between the multiple sound categories and the corresponding evoked spatial patterns and classify the unlabeled sound-evoked patterns significantly above chance. This indicates the feasibility of decoding multiple sound categories not only within but across subjects. However, the across-subject variation affects classification performance more than the within-subject variation, as the across-subject analysis has significantly lower classification accuracies. Sound category-selective brain maps were identified based on multi-class classification and revealed distributed patterns of brain activity in the superior temporal gyrus and the middle temporal gyrus. This is in accordance with previous studies, indicating that information in the spatially distributed patterns may reflect a more abstract perceptual level of representation of sound categories. Further, we show that the across-subject classification performance can be significantly improved by averaging the f

  14. Decoding multiple sound categories in the human temporal cortex using high resolution fMRI.

    PubMed

    Zhang, Fengqing; Wang, Ji-Ping; Kim, Jieun; Parrish, Todd; Wong, Patrick C M

    2015-01-01

    Perception of sound categories is an important aspect of auditory perception. The extent to which the brain's representation of sound categories is encoded in specialized subregions or distributed across the auditory cortex remains unclear. Recent studies using multivariate pattern analysis (MVPA) of brain activations have provided important insights into how the brain decodes perceptual information. In the large existing literature on brain decoding using MVPA methods, relatively few studies have been conducted on multi-class categorization in the auditory domain. Here, we investigated the representation and processing of auditory categories within the human temporal cortex using high resolution fMRI and MVPA methods. More importantly, we considered decoding multiple sound categories simultaneously through multi-class support vector machine-recursive feature elimination (MSVM-RFE) as our MVPA tool. Results show that for all classifications the model MSVM-RFE was able to learn the functional relation between the multiple sound categories and the corresponding evoked spatial patterns and classify the unlabeled sound-evoked patterns significantly above chance. This indicates the feasibility of decoding multiple sound categories not only within but across subjects. However, the across-subject variation affects classification performance more than the within-subject variation, as the across-subject analysis has significantly lower classification accuracies. Sound category-selective brain maps were identified based on multi-class classification and revealed distributed patterns of brain activity in the superior temporal gyrus and the middle temporal gyrus. This is in accordance with previous studies, indicating that information in the spatially distributed patterns may reflect a more abstract perceptual level of representation of sound categories. Further, we show that the across-subject classification performance can be significantly improved by averaging the f

  15. Agro-hydrology and multi temporal high resolution remote sensing: toward an explicit spatial processes calibration

    NASA Astrophysics Data System (ADS)

    Ferrant, S.; Gascoin, S.; Veloso, A.; Salmon-Monviola, J.; Claverie, M.; Rivalland, V.; Dedieu, G.; Demarez, V.; Ceschia, E.; Probst, J.-L.; Durand, P.; Bustillo, V.

    2014-07-01

    The recent and forthcoming availability of high resolution satellite image series offers new opportunities in agro-hydrological research and modeling. We investigated the perspective offered by improving the crop growth dynamic simulation using the distributed agro-hydrological model, Topography based Nitrogen transfer and Transformation (TNT2), using LAI map series derived from 105 Formosat-2 (F2) images during the period 2006-2010. The TNT2 model (Beaujouan et al., 2002), calibrated with discharge and in-stream nitrate fluxes for the period 1985-2001, was tested on the 2006-2010 dataset (climate, land use, agricultural practices, discharge and nitrate fluxes at the outlet). A priori agricultural practices obtained from an extensive field survey such as seeding date, crop cultivar, and fertilizer amount were used as input variables. Continuous values of LAI as a function of cumulative daily temperature were obtained at the crop field level by fitting a double logistic equation against discrete satellite-derived LAI. Model predictions of LAI dynamics with a priori input parameters showed an temporal shift with observed LAI profiles irregularly distributed in space (between field crops) and time (between years). By re-setting seeding date at the crop field level, we proposed an optimization method to minimize efficiently this temporal shift and better fit the crop growth against the spatial observations as well as crop production. This optimization of simulated LAI has a negligible impact on water budget at the catchment scale (1 mm yr-1 in average) but a noticeable impact on in-stream nitrogen fluxes (around 12%) which is of interest considering nitrate stream contamination issues and TNT2 model objectives. This study demonstrates the contribution of forthcoming high spatial and temporal resolution products of Sentinel-2 satellite mission in improving agro-hydrological modeling by constraining the spatial representation of crop productivity.

  16. Pan-Tropical Forest Mapping by Exploiting Textures of Multi-Temporal High Resolution SAR Data

    NASA Astrophysics Data System (ADS)

    Knuth, R.; Eckardt, R.; Richter, N.; Schmullius, C.

    2012-12-01

    radar images were processed using an operational processing chain that includes radiometric transformation, noise reduction, and georeferencing of the SAR data. In places with pronounced topography both satellites were used as single pass interferometer to derive a digital surface model in order to perform an orthorectification followed by a topographic normalization of the SAR backscatter values. As prescribed by the FAO, the final segment-based classification algorithm was fed by multi-temporal backscatter information, a set of textural features, and information on the degree of coherence between the multi-temporal acquisitions. Validation with available high resolution optical imagery suggests that the produced forest maps possess an overall accuracy of 75 percent or higher.

  17. Evaluation of high-resolution microarray platforms for genomic profiling of bone tumours

    PubMed Central

    2010-01-01

    Background Several high-density oligonucleotide microarray platforms are available for genome-wide single nucleotide polymorphism (SNP) detection and microarray-based comparative genomic hybridisation (array CGH), which may be used to detect copy number aberrations in human tumours. As part of the EuroBoNeT network of excellence for research on bone tumours (eurobonet.eu), we have evaluated four different commercial high-resolution microarray platforms in order to identify the most appropriate technology for mapping DNA copy number aberrations in such tumours. Findings DNA from two different cytogenetically well-characterized bone sarcoma cell lines, representing a simple and a complex karyotype, respectively, was tested in duplicate on four high-resolution microarray platforms; Affymetrix Genome-Wide Human SNP Array 6.0, Agilent Human Genome CGH 244A, Illumina HumanExon510s-duo and Nimblegen HG18 CGH 385 k WG tiling v1.0. The data was analysed using the platform-specific analysis software, as well as a platform-independent analysis algorithm. DNA copy number was measured at six specific chromosomes or chromosomal regions, and compared with the expected ratio based on available cytogenetic information. All platforms performed well in terms of reproducibility and were able to delimit and score small amplifications and deletions at similar resolution, but Agilent microarrays showed better linearity and dynamic range. The platform-specific analysis software provided with each platform identified in general correct copy numbers, whereas using a platform-independent analysis algorithm, correct copy numbers were determined mainly for Agilent and Affymetrix microarrays. Conclusions All platforms performed reasonably well, but Agilent microarrays showed better dynamic range, and like Affymetrix microarrays performed well with the platform-independent analysis software, implying more robust data. Bone tumours like osteosarcomas are heterogeneous tumours with complex

  18. Determination of Destructed and Infracted Forest Areas with Multi-temporal High Resolution Satellite Images

    NASA Astrophysics Data System (ADS)

    Seker, D. Z.; Unal, A.; Kaya, S.; Alganci, U.

    2015-12-01

    Migration from rural areas to city centers and their surroundings is an important problem of not only our country but also the countries that under development stage. This uncontrolled and huge amount of migration brings out urbanization and socio - economic problems. The demand on settling the industrial areas and commercial activities nearby the city centers results with a negative change in natural land cover on cities. Negative impacts of human induced activities on natural resources and land cover has been continuously increasing for decades. The main human activities that resulted with destruction and infraction of forest areas can be defined as mining activities, agricultural activities, industrial / commercial activities and urbanization. Temporal monitoring of the changes in spatial distribution of forest areas is significantly important for effective management and planning progress. Changes can occur as spatially large destructions or small infractions. Therefore there is a need for reliable, fast and accurate data sources. At this point, satellite images proved to be a good data source for determination of the land use /cover changes with their capability of monitoring large areas with reasonable temporal resolutions. Spectral information derived from images provides discrimination of land use/cover types from each other. Developments in remote sensing technology in the last decade improved the spatial resolution of satellites and high resolution images were started to be used to detect even small changes in the land surface. As being the megacity of Turkey, Istanbul has been facing a huge migration for the last 20 years and effects of urbanization and other human based activities over forest areas are significant. Main focus of this study is to determine the destructions and infractions in forest areas of Istanbul, Turkey with 2.5m resolution SPOT 5 multi-temporal satellite imagery. Analysis was mainly constructed on threshold based classification of

  19. Large-Scale, High-Resolution Neurophysiological Maps Underlying fMRI of Macaque Temporal Lobe

    PubMed Central

    Papanastassiou, Alex M.; DiCarlo, James J.

    2013-01-01

    Maps obtained by functional magnetic resonance imaging (fMRI) are thought to reflect the underlying spatial layout of neural activity. However, previous studies have not been able to directly compare fMRI maps to high-resolution neurophysiological maps, particularly in higher level visual areas. Here, we used a novel stereo microfocal x-ray system to localize thousands of neural recordings across monkey inferior temporal cortex (IT), construct large-scale maps of neuronal object selectivity at subvoxel resolution, and compare those neurophysiology maps with fMRI maps from the same subjects. While neurophysiology maps contained reliable structure at the sub-millimeter scale, fMRI maps of object selectivity contained information at larger scales (>2.5 mm) and were only partly correlated with raw neurophysiology maps collected in the same subjects. However, spatial smoothing of neurophysiology maps more than doubled that correlation, while a variety of alternative transforms led to no significant improvement. Furthermore, raw spiking signals, once spatially smoothed, were as predictive of fMRI maps as local field potential signals. Thus, fMRI of the inferior temporal lobe reflects a spatially low-passed version of neurophysiology signals. These findings strongly validate the widespread use of fMRI for detecting large (>2.5 mm) neuronal domains of object selectivity but show that a complete understanding of even the most pure domains (e.g., faces vs nonface objects) requires investigation at fine scales that can currently only be obtained with invasive neurophysiological methods. PMID:24048850

  20. Usher's syndrome, temporal bone pathology.

    PubMed

    Cremers, C W; Delleman, W J

    1988-10-01

    The histological findings in the right temporal bone of a 65-year-old deaf and blind man are presented. The subject suffered from the autosomal recessive Usher's syndrome, as did 2 of his 5 siblings. They are the offspring of a consanguineous marriage. This man died from an intra-abdominal hemorrhage. Within 3 h after death the temporal bones were donated for study and were processed for histopathological examination.

  1. Chondroblastoma of the Temporal Bone

    PubMed Central

    Selesnick, Samuel H.; Levine, Jennifer M.

    1999-01-01

    The objective of this study is to describe the presentation and clinical course of two patients with temporal bone chondroblastoma, and to review the literature on temporal bone chondroblastoma to identify characteristic clinical and radiological presentations, and optimal treatment regimens. MEDLINE literature searches covering the period from 1966 to January 1998, in all languages, were performed as well as a review of the bibliographies of the identified studies. Strict inclusion criteria were upheld, In total 18 studies had patients whose data could be analyzed. From the 18 studies, 34 patients were identified, but only 21 cases met the inclusion criteria. Demographic, clinical presentation, radiological, operative and treatment parameters were analyzed in this cohort of patients. Ninety-five percent of patients were found to have invasion of the middle cranial fossa and 76% were found to have erosion into the superior aspect of the external auditory canal by temporal bone chondroblastoma. The characteristic growth pattern of temporal bone chondroblastoma may result from embryonal or cartilagenous rests entrapped in the tympanosquamous suture line in the middle fossa floor. Temporal bone chondroblastoma represents a pathology that does not arise from, or have a growth pattern resembling other pathologies in the temporal bone. ImagesFigure 1Figure 2 PMID:17171120

  2. The Impact of Horizontal and Temporal Resolution on Convection and Precipitation with High-Resolution GEOS-5

    NASA Technical Reports Server (NTRS)

    Putman, William P.

    2012-01-01

    Using a high-resolution non-hydrostatic version of GEOS-5 with the cubed-sphere finite-volume dynamical core, the impact of spatial and temporal resolution on cloud properties will be evaluated. There are indications from examining convective cluster development in high resolution GEOS-5 forecasts that the temporal resolution within the model may playas significant a role as horizontal resolution. Comparing modeled convective cloud clusters versus satellite observations of brightness temperature, we have found that improved. temporal resolution in GEOS-S accounts for a significant portion of the improvements in the statistical distribution of convective cloud clusters. Using satellite simulators in GEOS-S we will compare the cloud optical properties of GEOS-S at various spatial and temporal resolutions with those observed from MODIS. The potential impact of these results on tropical cyclone formation and intensity will be examined as well.

  3. A high resolution temporal study of phytoplankton bloom dynamics in the eutrophic Taw Estuary (SW England).

    PubMed

    Maier, Gerald; Glegg, Gillian A; Tappin, Alan D; Worsfold, Paul J

    2012-09-15

    The Taw Estuary (SW England) is eutrophic as a result of enhanced nutrient inputs from its catchment. However, factors influencing the timing and extent of phytoplankton bloom formation are not fully understood in this system. In this study, high resolution chemical and biological sampling was undertaken in late-winter/spring and summer 2008 in order to gain further insights into bloom dynamics in the Taw Estuary. Temporal variations in chlorophyll a maxima in the upper and middle estuary during summer were controlled by river flow and tidal amplitude, with nutrient limitation probably less important. Concentrations of chlorophyll a were highest during low river flow and neap tides. Increased river flows advected the chlorophyll maximum to the outer estuary, and under highest river discharges, chlorophyll a concentrations were further reduced. This feature was even more pronounced when spring tides coincided with high flows. The main bloom species were the diatoms Asterionellopsis glacialis and Thalassiosira guillardii. Using two multivariate statistical techniques in combination, five distinct physical and biogeochemical states in the Taw estuarine waters were identified. These states can be summarised as: A(1), high chlorophyll a, high temperature, long residence times, nutrient depletion; A(2), strong coastal water influence; B(1), decreasing chlorophyll a, increasing river flow and/or spring tides; B(2), transitional between states A(1) and B(3); B(3), high river flow. It was thus possible to differentiate between contrasting environmental conditions that were either beneficial or detrimental for the development of algal blooms. A conceptual model of diatom - dominated primary production for the Taw Estuary is proposed which describes how physical controls (river flow, tidal state) moderate plankton biomass production in the upper and mid - estuarine regions. Copyright © 2011 Elsevier B.V. All rights reserved.

  4. Improved reproducibility of high-resolution peripheral quantitative computed tomography for measurement of bone quality.

    PubMed

    MacNeil, Joshua A; Boyd, Steven K

    2008-07-01

    A human high-resolution peripheral quantitative computed tomography scanner (HR-pQCT) (XtremeCT, Scanco Medical, Switzerland) capable of measuring three important indicators of bone quality (micro-architectural morphology, mineralization and mechanical stiffness) has been developed. The goal of this study was to evaluate the reproducibility of male and female HR-pQCT in vivo measurements, and elucidate the causes of error in these measurements through a comparison with in vitro measurements. The best possible short-term reproducibility was found using a set of 10 in vitro measurements without repositioning, and a set of 10 with repositioning. Subsequently, in vivo measurements were performed on 15 male and 15 female subjects at baseline and follow-ups of 1 week and 4 months to determine the short- and long-term reproducibility of the system. In addition to the 2D area matching method used in the standard evaluation protocol, a custom developed 3D registration method was used to find the common region between repeated scans. The best possible reproducibility without movement artifacts and repositioning error was less than 0.5%, while the reproducibility with repositioning error was less than 1.5%. The in vivo reproducibility of density (<1%), morphological (<4.5%) and stiffness (<3.5) measurements was consistently poorer than the reproducibility of cadaver measurements, presumably due to small movement artifacts and repositioning errors. Using 3D image registration, repositioning error was reduced on average by 23% and 8% for measurements of the radius and tibia sites, respectively. This study has provided bounds for the reproducibility of HR-pQCT to monitor bone quality longitudinally, and a basis for clinical study design to determine detectable changes.

  5. High resolution bone material property assignment yields robust subject specific finite element models of complex thin bone structures.

    PubMed

    Pakdel, Amirreza; Fialkov, Jeffrey; Whyne, Cari M

    2016-06-14

    Accurate finite element (FE) modeling of complex skeletal anatomy requires high resolution in both meshing and the heterogeneous mapping of material properties onto the generated mesh. This study introduces Node-based elastic Modulus Assignment with Partial-volume correction (NMAP) as a new approach for FE material property assignment to thin bone structures. The NMAP approach incorporates point spread function based deblurring of CT images, partial-volume correction of CT image voxel intensities and anisotropic interpolation and mapping of CT intensity assignment to FE mesh nodes. The NMAP procedure combined with a derived craniomaxillo-facial skeleton (CMFS) specific density-isotropic elastic modulus relationship was applied to produce specimen-specific FE models of 6 cadaveric heads. The NMAP procedure successfully generated models of the complex thin bone structures with surface elastic moduli reflective of cortical bone material properties. The specimen-specific CMFS FE models were able to accurately predict experimental strains measured under in vitro temporalis and masseter muscle loading (r=0.93, slope=1.01, n=5). The strength of this correlation represents a robust validation for CMFS FE modeling that can be used to better understand load transfer in this complex musculoskeletal system. The developed methodology offers a systematic process-flow able to address the complexity of the CMFS that can be further applied to create high-fidelity models of any musculoskeletal anatomy. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Temporal bone chondroblastoma: a review.

    PubMed

    Bian, Liu-Guan; Sun, Qing-Fang; Zhao, Wei-Guo; Shen, Jian-Kang; Tirakotai, Wuttipong; Bertalanffy, Helmult

    2005-06-01

    The objective of this paper was to review temporal bone chondroblastomas in regard to their presentation, radiographic findings, histopathology, and treatment. A case report of a 38-year-old man who presented with the left-sided hearing impairment and temporal swelling was reviewed. A CT scan revealed an osteolytic lobulated expansile mass. MRI depicted two cystic components with fluid-fluid level and enhanced solid mass. Immunohistochemical study of S-100 was performed using avidinbiotin-complex method. The tumor was totally removed, with eroded squamous bone and temporal muscle, via the left zygomatic-extended middle fossa approach. The pathology of the tumor showed that the tumor cell was spindle-shaped, along with multinucleated giant cells. These cells had oval to polygonal nuclei; some cells showed grooved nuclei. Intercelluar calcification and hemorrhagic components were also observed in the tumor. Tumor cells were strongly positive for S-100 protein. Temporal bone chondroblastomas are extremely rare osseous tumors with only 45 cases previously reported in the published literature. They may be confused with more common lesions seen in the temporal bone. Diagnostic radiology, including CT and/or MRI, as well as immunohistochemical staining with S-100 protein, may assist in making the diagnosis. Treatment is complete surgical excision with preservation of vital neurovascular structures.

  7. Decoding Overlapping Memories in the Medial Temporal Lobes Using High-Resolution fMRI

    ERIC Educational Resources Information Center

    Chadwick, Martin J.; Hassabis, Demis; Maguire, Eleanor A.

    2011-01-01

    The hippocampus is proposed to process overlapping episodes as discrete memory traces, although direct evidence for this in human episodic memory is scarce. Using green-screen technology we created four highly overlapping movies of everyday events. Participants were scanned using high-resolution fMRI while recalling the movies. Multivariate…

  8. Decoding Overlapping Memories in the Medial Temporal Lobes Using High-Resolution fMRI

    ERIC Educational Resources Information Center

    Chadwick, Martin J.; Hassabis, Demis; Maguire, Eleanor A.

    2011-01-01

    The hippocampus is proposed to process overlapping episodes as discrete memory traces, although direct evidence for this in human episodic memory is scarce. Using green-screen technology we created four highly overlapping movies of everyday events. Participants were scanned using high-resolution fMRI while recalling the movies. Multivariate…

  9. A Novel Temporal Bone Simulation Model Using 3D Printing Techniques.

    PubMed

    Mowry, Sarah E; Jammal, Hachem; Myer, Charles; Solares, Clementino Arturo; Weinberger, Paul

    2015-09-01

    An inexpensive temporal bone model for use in a temporal bone dissection laboratory setting can be made using a commercially available, consumer-grade 3D printer. Several models for a simulated temporal bone have been described but use commercial-grade printers and materials to produce these models. The goal of this project was to produce a plastic simulated temporal bone on an inexpensive 3D printer that recreates the visual and haptic experience associated with drilling a human temporal bone. Images from a high-resolution CT of a normal temporal bone were converted into stereolithography files via commercially available software, with image conversion and print settings adjusted to achieve optimal print quality. The temporal bone model was printed using acrylonitrile butadiene styrene (ABS) plastic filament on a MakerBot 2x 3D printer. Simulated temporal bones were drilled by seven expert temporal bone surgeons, assessing the fidelity of the model as compared with a human cadaveric temporal bone. Using a four-point scale, the simulated bones were assessed for haptic experience and recreation of the temporal bone anatomy. The created model was felt to be an accurate representation of a human temporal bone. All raters felt strongly this would be a good training model for junior residents or to simulate difficult surgical anatomy. Material cost for each model was $1.92. A realistic, inexpensive, and easily reproducible temporal bone model can be created on a consumer-grade desktop 3D printer.

  10. Protocol for volumetric segmentation of medial temporal structures using high-resolution 3-D magnetic resonance imaging.

    PubMed

    Bonilha, Leonardo; Kobayashi, Eliane; Cendes, Fernando; Min Li, Li

    2004-06-01

    Quantitative analysis of brain structures in normal subjects and in different neurological conditions can be carried out in vivo through magnetic resonance imaging (MRI) volumetric studies. The use of high-resolution MRI combined with image post-processing that allows simultaneous multiplanar view may facilitate volumetric segmentation of temporal lobe structures. We define a protocol for volumetric studies of medial temporal lobe structures using high-resolution MR images and we studied 30 healthy subjects (19 women; mean age, 33 years; age range, 21-55 years). Images underwent field non-homogeneity correction and linear stereotaxic transformation into a standard space. Structures of interest comprised temporopolar, entorhinal, perirhinal, parahippocampal cortices, hippocampus, and the amygdala. Segmentation was carried out with multiplanar assessment. There was no statistically significant left/right-sided asymmetry concerning any structure analyzed. Neither gender nor age influenced the volumes obtained. The coefficient of repeatability showed no significant difference of intra- and interobserver measurements. Imaging post-processing and simultaneous multiplanar view of high-resolution MRI facilitates volumetric assessment of the medial portion of the temporal lobe with strict adherence to anatomic landmarks. This protocol shows no significant inter- and intraobserver variations and thus is reliable for longitudinal studies.

  11. High-resolution-cone beam tomography analysis of bone microarchitecture in patients with acromegaly and radiological vertebral fractures.

    PubMed

    Maffezzoni, Filippo; Maddalo, Michele; Frara, Stefano; Mezzone, Monica; Zorza, Ivan; Baruffaldi, Fabio; Doglietto, Francesco; Mazziotti, Gherardo; Maroldi, Roberto; Giustina, Andrea

    2016-11-01

    Vertebral fractures are an emerging complication of acromegaly but their prediction is still difficult occurring even in patients with normal bone mineral density. In this study we evaluated the ability of high-resolution cone-beam computed tomography to provide information on skeletal abnormalities associated with vertebral fractures in acromegaly. 40 patients (24 females, 16 males; median age 57 years, range 25-72) and 21 healthy volunteers (10 females, 11 males; median age 60 years, range: 25-68) were evaluated for trabecular (bone volume/trabecular volume ratio, mean trabecular separation, and mean trabecular thickness) and cortical (thickness and porosity) parameters at distal radius using a high-resolution cone-beam computed tomography system. All acromegaly patients were evaluated for morphometric vertebral fractures and for mineral bone density by dual-energy X-ray absorptiometry at lumbar spine, total hip, femoral neck, and distal radius. Acromegaly patients with vertebral fractures (15 cases) had significantly (p < 0.05) lower bone volume/trabecular volume ratio, greater mean trabecular separation, and higher cortical porosity vs. nonfractured patients, without statistically significant differences in mean trabecular thickness and cortical thickness. Fractured and nonfractured acromegaly patients did not have significant differences in bone density at either skeletal site. Patients with acromegaly showed lower bone volume/trabecular volume ratio (p = 0.003) and mean trabecular thickness (p < 0.001) and greater mean trabecular separation (p = 0.02) as compared to control subjects, without significant differences in cortical thickness and porosity. This study shows for the first time that abnormalities of bone microstructure are associated with radiological vertebral fractures in acromegaly. High-resolution cone-beam computed tomography at the distal radius may be useful to evaluate and predict the effects of acromegaly on bone

  12. Combining high-resolution micro-computed tomography with material composition to define the quality of bone tissue.

    PubMed

    Judex, Stefan; Boyd, Steve; Qin, Yi-Xian; Miller, Lisa; Müller, Ralph; Rubin, Clinton

    2003-06-01

    Atraumatic fractures of the skeleton in osteoporotic patients are directly related to a deterioration of bone strength. However, the failure of the bone tissue to withstand functional load bearing cannot be explained as a simple decrease in bone mineral density (quantity); strength is also significantly dependent upon bone quality. While a formal definition of bone quality is somewhat elusive, at the very least, it incorporates architectural, physical, and biologic factors that are critical to bone strength. Such factors include bone morphology (ie, trabecular connectivity, cross-sectional geometry, longitudinal curvature); the tissue's material properties (eg, stiffness, strength); its chemical composition and architecture (eg, ratio of calcium to other components of the organic and/or inorganic phase, collagen orientation, porosity, permeability); and the viability of the tissue (eg, responsivity of the bone cell population). Combining high-resolution structural indices of bone, as determined by micro-computed tomography; material properties determined by nanoindentation; and the chemical make-up of bone, as determined by infrared spectroscopy, helps to provide critical information toward a more comprehensive assessment of the interdependence of bone quality, quantity, and fracture risk.

  13. High dynamic, high resolution and wide range single shot temporal pulse contrast measurement.

    PubMed

    Oksenhendler, Thomas; Bizouard, Pierre; Albert, Olivier; Bock, Stefan; Schramm, Ulrich

    2017-05-29

    A novel apparatus for the single-shot measurement of the temporal pulse contrast of modern ultra-short pulse lasers is presented, based on a simple yet conceptual refinement of the self-referenced spectral interferometry (SRSI) approach. The introduction of the spatial equivalent of a temporal delay by tilted beams analyzed with a high quality imaging spectrometer, enables unprecedented performance in dynamic, temporal range and resolution simultaneously. Demonstrated consistently in simulation and experiment at the front-end of the PW laser Draco, the full range of the ps temporal contrast defining the quality of relativistic laser-solid interaction could be measured with almost 80 dB dynamic range, 18ps temporal window, and 18fs temporal resolution. Additionally, spatio-temporal coupling as in the case of a pulse front tilt can be quantitatively explored.

  14. Children and adolescents with cystic fibrosis display moderate bone microarchitecture abnormalities: data from high-resolution peripheral quantitative computed tomography.

    PubMed

    Braun, C; Bacchetta, J; Braillon, P; Chapurlat, R; Drai, J; Reix, P

    2017-08-09

    We investigated whether bone microstructure assessed by high-resolution peripheral quantitative tomography (HR-pQCT) could be altered in children and teenagers with cystic fibrosis (CF). In comparison to their healthy counterparts, bone microstructure was mildly affected at the tibial level only. Cystic fibrosis-related bone disease (CFBD) may alter bone health, ultimately predisposing patients to bone fractures. Our aim was to assess bone microstructure using high-resolution peripheral quantitative tomography (HR-pQCT) in a cohort of children and teenagers with CF in comparison to age-, puberty-, and gender-matched healthy volunteers (HVs). In this single-center, prospective, cross-sectional study, we evaluated the HR-pQCT bone parameters of CF patients and compared them to those of the healthy volunteers. At a median age of 15.4 [range, 10.5-17.9] years, 37 CF patients (21 boys) with 91% [range, 46-138%] median forced expiratory volume in 1 s were included. At the ultradistal tibia, CF patients had a smaller bone cross-sectional area (579 [range, 399-1087] mm(2)) than HVs (655 [range, 445-981] mm(2)) (p = 0.027), related to a decreased trabecular area, without any significant differences for height. No other differences were found (trabecular number, separation, thickness, or distribution) at the radial or tibial levels. Bone structure was different in patients receiving ursodeoxycholic acid and those bearing two F508del mutations. In our cohort of children and teenagers with good nutritional and lung function status, bone microstructure evaluated with HR-pQCT was not severely affected. Minimal microstructure abnormalities observed at the tibial level may be related to the cystic fibrosis transmembrane conductance regulator defect alone; the long-term consequences of such impairment will require further evaluation.

  15. The evolution of active Lavina di Roncovetro landslides by multi-temporal high-resolution topographic data

    NASA Astrophysics Data System (ADS)

    Isola, Ilaria; Fornaciai, Alessandro; Favalli, Massimiliano; Gigli, Giovanni; Nannipieri, Luca; Mucchi, Lorenzo; Intrieri, Emanuele; Pizziolo, Marco; Bertolini, Giovanni; Trippi, Federico; Casagli, Nicola; Schina, Rosa; Carnevale, Ennio

    2017-04-01

    High-resolution topographic data has been collected over the Lavina di Roncovetro active landslide (Reggio Emilia, Italy) for about 3 years by using various methods and technologies. Tha Lavina di Roncovetro landslide can be considered as a fluid-viscous mudflow, which can reach a down flow maximum rate of 10 m/day. The landslide started between the middle and the end of the XIX century and since then it has had a rapid evolution mainly characterized by the rapid retrogression of the crown to the extent that now reaches the top of Mount Staffola. In the frame of EU Wireless Sensor Network for Ground Instability Monitoring - Wi-GIM project (LIFE12ENV/IT/001033) the Lavina di Roncovetro landslide has been periodically tracked using technologies that span from the LiDAR, both terrestrial and aerial, to the Structure from Motion (SfM) photogrammetry method based on Unmanned Aerial Vehicle (UAV) and aerial survey. These data are used to create six high-resolution Digital Terrain Models (DEMs), which imaged the landslide surface on March 2014, October 2014, June 2015, July 2015, January 2016 and December 2016. Multi-temporal high-resolution topographic data have been used for qualitative and quantitative morphometric analysis and topographic change detection of the landslide with the aim to estimate and map the volume of removed and/or accumulated material, the average rates of vertical and horizontal displacement and the deformation structures affecting the landslide over the investigated period.

  16. Visual short-term memory for high resolution associations is impaired in patients with medial temporal lobe damage.

    PubMed

    Koen, Joshua D; Borders, Alyssa A; Petzold, Michael T; Yonelinas, Andrew P

    2017-02-01

    The medial temporal lobe (MTL) plays a critical role in episodic long-term memory, but whether the MTL is necessary for visual short-term memory is controversial. Some studies have indicated that MTL damage disrupts visual short-term memory performance whereas other studies have failed to find such evidence. To account for these mixed results, it has been proposed that the hippocampus is critical in supporting short-term memory for high resolution complex bindings, while the cortex is sufficient to support simple, low resolution bindings. This hypothesis was tested in the current study by assessing visual short-term memory in patients with damage to the MTL and controls for high resolution and low resolution object-location and object-color associations. In the location tests, participants encoded sets of two or four objects in different locations on the screen. After each set, participants performed a two-alternative forced-choice task in which they were required to discriminate the object in the target location from the object in a high or low resolution lure location (i.e., the object locations were very close or far away from the target location, respectively). Similarly, in the color tests, participants were presented with sets of two or four objects in a different color and, after each set, were required to discriminate the object in the target color from the object in a high or low resolution lure color (i.e., the lure color was very similar or very different, respectively, to the studied color). The patients were significantly impaired in visual short-term memory, but importantly, they were more impaired for high resolution object-location and object-color bindings. The results are consistent with the proposal that the hippocampus plays a critical role in forming and maintaining complex, high resolution bindings. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  17. Can high-resolution peripheral quantitative computed tomography imaging of subchondral and cortical bone predict condylar fracture in Thoroughbred racehorses?

    PubMed

    Trope, G D; Ghasem-Zadeh, A; Anderson, G A; Mackie, E J; Whitton, R C

    2015-07-01

    High-resolution 3D imaging may improve the prediction and/or early identification of condylar fractures of the distal metacarpus/tarsus and reduce the frequency of breakdown injury in racehorses. To test the hypotheses that horses suffering condylar fractures have higher bone volume fraction (BV/TV) of the distal metacarpal epiphysis, greater subchondral bone thickness at the fracture site and higher second moment of inertia in the metacarpal midshaft as identified with high-resolution 3D imaging. Cross-sectional study using cadaver material. Thoroughbreds that died on racetracks were grouped as: 1) horses with third metacarpal (McIII) fractures with a condylar component (cases, n = 13); 2) horses with no limb fracture (controls, n = 8); 3) horses with fractures in other bones or suspensory apparatus disruption (other fatal injuries, n = 16). The palmar condyles of McIII and the midshaft were examined with high resolution peripheral quantitative computed tomography (HR-pQCT). Statistical analysis included logistic regression and Spearman's correlation. There were no significant differences in BV/TV of distal McIII and second moment of inertia of the midshaft between cases and controls. Epiphyseal bone BV/TV was greater in injured limbs of horses with any fatal limb injury (Groups 1 and 3 combined) compared with controls (odds ratio = 1.20, 95% confidence interval 1.01-1.42, P = 0.034). An epiphyseal BV/TV>0.742 resulted in a sensitivity of 82.8% and specificity of 62.5% in identifying horses with fatal limb injury. In horses without condylar fracture, increased subchondral bone thickness was associated with palmar osteochondral disease lesions in the adjacent condyle (rs = 0.65, P<0.001). Increased BV/TV of the distal metacarpus may have some value for identifying horses at risk of any fatal breakdown injury but not metacarpal condylar fractures. Measurement of parasagittal groove subchondral bone thickness is complicated by adjacent palmar osteochondral disease

  18. High-resolution measurements of the spatial and temporal scalar structure of a turbulent plume

    NASA Astrophysics Data System (ADS)

    Crimaldi, J. P.; Koseff, J. R.

    Two techniques are described for measuring the scalar structure of turbulent flows. A planar laser-induced fluorescence technique is used to make highly resolved measurements of scalar spatial structure, and a single-point laser-induced fluorescence probe is used to make highly resolved measurements of scalar temporal structure. The techniques are used to measure the spatial and temporal structure of an odor plume released from a low-momentum, bed-level source in a turbulent boundary layer. For the experimental setup used in this study, a spatial resolution of 150μm and a temporal resolution of 1,000Hz are obtained. The results show a wide range of turbulent structures in rich detail; the nature of the structure varies significantly in different regions of the plume.

  19. Multi-temporal high resolution monitoring of debris-covered glaciers using unmanned aerial vehicles

    NASA Astrophysics Data System (ADS)

    Kraaijenbrink, Philip; Immerzeel, Walter; de Jong, Steven; Shea, Joseph; Pellicciotti, Francesca; Meijer, Sander; Shresta, Arun

    2016-04-01

    Debris-covered glaciers in the Himalayas are relatively unstudied due to the difficulties in fieldwork caused by the inaccessible terrain and the presence of debris layers, which complicate in situ measurements. To overcome these difficulties an unmanned aerial vehicle (UAV) has been deployed multiple times over two debris covered glaciers in the Langtang catchment, located in the Nepalese Himalayas. Using differential GPS measurements and the Structure for Motion algorithm the UAV imagery was processed into accurate high-resolution digital elevation models and orthomosaics for both pre- and post-monsoon periods. These data were successfully used to estimate seasonal surface flow and mass wasting by using cross-correlation feature tracking and DEM differencing techniques. The results reveal large heterogeneity in mass loss and surface flow over the glacier surfaces, which are primarily caused by the presence of surface features such as ice cliffs and supra-glacial lakes. Accordingly, we systematically analyze those features using an object-based approach and relate their characteristics to the observed dynamics. We show that ice cliffs and supra-glacial lakes are contributing to a significant portion of the melt water of debris covered glaciers and we conclude that UAVs have great potential in understanding the key surface processes that remain largely undetected by using satellite remote sensing.

  20. Temporal Dynamics of Motivation-Cognitive Control Interactions Revealed by High-Resolution Pupillometry

    PubMed Central

    Chiew, Kimberly S.; Braver, Todd S.

    2013-01-01

    Motivational manipulations, such as the presence of performance-contingent reward incentives, can have substantial influences on cognitive control. Previous evidence suggests that reward incentives may enhance cognitive performance specifically through increased preparatory, or proactive, control processes. The present study examined reward influences on cognitive control dynamics in the AX-Continuous Performance Task (AX-CPT), using high-resolution pupillometry. In the AX-CPT, contextual cues must be actively maintained over a delay in order to appropriately respond to ambiguous target probes. A key feature of the task is that it permits dissociable characterization of preparatory, proactive control processes (i.e., utilization of context) and reactive control processes (i.e., target-evoked interference resolution). Task performance profiles suggested that reward incentives enhanced proactive control (context utilization). Critically, pupil dilation was also increased on reward incentive trials during context maintenance periods, suggesting trial-specific shifts in proactive control, particularly when context cues indicated the need to overcome the dominant target response bias. Reward incentives had both transient (i.e., trial-by-trial) and sustained (i.e., block-based) effects on pupil dilation, which may reflect distinct underlying processes. The transient pupillary effects were present even when comparing against trials matched in task performance, suggesting a unique motivational influence of reward incentives. These results suggest that pupillometry may be a useful technique for investigating reward motivational signals and their dynamic influence on cognitive control. PMID:23372557

  1. High Resolution Temporal and Spectral Monitoring of Eta Carinae's X-Ray Emission the June Eclipse

    NASA Technical Reports Server (NTRS)

    Corcoran, M. F.; Hamaguchi, K.; Henley, D.; Pittard, J. M.; Gull, T. R.; Davidson, K.; Swank, J. H.; Petre, R.; Ishibashi, K.

    2004-01-01

    The supermassive and luminous star Eta Carinae undergoes strong X-ray variations every 5.5 years when its 2-10 keV X-ray emission brightens rapidly with wild fluctuations before dropping by a factor of 100 to a minimum lasting 3 months. The most recent X-ray "eclipse" began in June 2003 and during this time Eta Carinae was intensely observed throughout the electromagnetic spectrum. Here we report the first results of frequent monitoring of the 2-10 keV band X-ray emission by the Rossi X-ray Timing Explorer along wit high resolution X-ray spectra obtained with the transmission gratings on the Chandra X-ray Observatory. We compare these observations to those results obtained during the previous X-ray eclipse in 1998, and interpret the variations in the X-ray brightness, in the amount of absorption, in the X-ray emission measure and in the K-shell emission lines in terms of a colliding wind binary model.

  2. Temporal dynamics of motivation-cognitive control interactions revealed by high-resolution pupillometry.

    PubMed

    Chiew, Kimberly S; Braver, Todd S

    2013-01-01

    Motivational manipulations, such as the presence of performance-contingent reward incentives, can have substantial influences on cognitive control. Previous evidence suggests that reward incentives may enhance cognitive performance specifically through increased preparatory, or proactive, control processes. The present study examined reward influences on cognitive control dynamics in the AX-Continuous Performance Task (AX-CPT), using high-resolution pupillometry. In the AX-CPT, contextual cues must be actively maintained over a delay in order to appropriately respond to ambiguous target probes. A key feature of the task is that it permits dissociable characterization of preparatory, proactive control processes (i.e., utilization of context) and reactive control processes (i.e., target-evoked interference resolution). Task performance profiles suggested that reward incentives enhanced proactive control (context utilization). Critically, pupil dilation was also increased on reward incentive trials during context maintenance periods, suggesting trial-specific shifts in proactive control, particularly when context cues indicated the need to overcome the dominant target response bias. Reward incentives had both transient (i.e., trial-by-trial) and sustained (i.e., block-based) effects on pupil dilation, which may reflect distinct underlying processes. The transient pupillary effects were present even when comparing against trials matched in task performance, suggesting a unique motivational influence of reward incentives. These results suggest that pupillometry may be a useful technique for investigating reward motivational signals and their dynamic influence on cognitive control.

  3. High Resolution Temporal and Spectral Monitoring of Eta Carinae's X-Ray Emission the June Eclipse

    NASA Technical Reports Server (NTRS)

    Corcoran, M. F.; Hamaguchi, K.; Henley, D.; Pittard, J. M.; Gull, T. R.; Davidson, K.; Swank, J. H.; Petre, R.; Ishibashi, K.

    2004-01-01

    The supermassive and luminous star Eta Carinae undergoes strong X-ray variations every 5.5 years when its 2-10 keV X-ray emission brightens rapidly with wild fluctuations before dropping by a factor of 100 to a minimum lasting 3 months. The most recent X-ray "eclipse" began in June 2003 and during this time Eta Carinae was intensely observed throughout the electromagnetic spectrum. Here we report the first results of frequent monitoring of the 2-10 keV band X-ray emission by the Rossi X-ray Timing Explorer along wit high resolution X-ray spectra obtained with the transmission gratings on the Chandra X-ray Observatory. We compare these observations to those results obtained during the previous X-ray eclipse in 1998, and interpret the variations in the X-ray brightness, in the amount of absorption, in the X-ray emission measure and in the K-shell emission lines in terms of a colliding wind binary model.

  4. Temporal High-Resolution Computed Tomography and Magnetic Resonance Imaging of Congenital Inner Ear Anomalies in Children.

    PubMed

    Palabiyik, Figen Bakirtas; Hacikurt, Kadir

    2016-10-01

    Imaging plays an important role in determining indications of cochlear implantation and choosing candidates for the procedure in children. Temporal high-resolution computed tomography (HRCT) and magnetic resonance imaging (MRI) can display precisely the complex anatomic structure of inner ear. Although HRCT permits detailed imaging of bony structures, MRI gives valuable information about membranous labyrinth, internal acoustic canal, and vestibulocochlear nerve. Magnetic resonance imaging examination of the brain should be performed at the same time to evaluate any coexistent brain parenchymal abnormality. These imaging modalities are complementary methods in evaluating congenital inner ear anomalies. The aim of this pictorial essay is to reviewing temporal HRCT and MRI findings of congenital inner ear anomalies.

  5. Stochastic multiscale modelling of cortical bone elasticity based on high-resolution imaging.

    PubMed

    Sansalone, Vittorio; Gagliardi, Davide; Desceliers, Christophe; Bousson, Valérie; Laredo, Jean-Denis; Peyrin, Françoise; Haïat, Guillaume; Naili, Salah

    2016-02-01

    Accurate and reliable assessment of bone quality requires predictive methods which could probe bone microstructure and provide information on bone mechanical properties. Multiscale modelling and simulation represent a fast and powerful way to predict bone mechanical properties based on experimental information on bone microstructure as obtained through X-ray-based methods. However, technical limitations of experimental devices used to inspect bone microstructure may produce blurry data, especially in in vivo conditions. Uncertainties affecting the experimental data (input) may question the reliability of the results predicted by the model (output). Since input data are uncertain, deterministic approaches are limited and new modelling paradigms are required. In this paper, a novel stochastic multiscale model is developed to estimate the elastic properties of bone while taking into account uncertainties on bone composition. Effective elastic properties of cortical bone tissue were computed using a multiscale model based on continuum micromechanics. Volume fractions of bone components (collagen, mineral, and water) were considered as random variables whose probabilistic description was built using the maximum entropy principle. The relevance of this approach was proved by analysing a human bone sample taken from the inferior femoral neck. The sample was imaged using synchrotron radiation micro-computed tomography. 3-D distributions of Haversian porosity and tissue mineral density extracted from these images supplied the experimental information needed to build the stochastic models of the volume fractions. Thus, the stochastic multiscale model provided reliable statistical information (such as mean values and confidence intervals) on bone elastic properties at the tissue scale. Moreover, the existence of a simpler "nominal model", accounting for the main features of the stochastic model, was investigated. It was shown that such a model does exist, and its relevance

  6. Challenges of High Resolution Diffusion Imaging of the Human Medial Temporal Lobe in Alzheimer's Disease

    PubMed Central

    Zeineh, Michael M.; Holdsworth, Samantha; Skare, Stefan; Atlas, Scott W.; Bammer, Roland

    2011-01-01

    The human medial temporal lobe performs an essential role in memory formation and retrieval. Diseases involving the hippocampus such as Alzheimer's disease present a unique opportunity for advanced imaging techniques to detect abnormalities at an early stage. In particular, it is possible that diffusion imaging may measure abnormal microarchitecture beyond the realm of macroscopic imaging. However, this task is formidable because of the detailed anatomy of the medial temporal lobe, the difficulties in obtaining high quality diffusion images of adequate resolution, and challenges in diffusion data processing. Moreover, it is unclear if any differences will be significant for an individual patient or simply groups of patients. Successful endeavors will need to address each of these challenges in an integrated fashion. The rewards of such analysis may be detection of microscopic disease in vivo, which could represent a landmark accomplishment for the field of neuroradiology. PMID:22158129

  7. Using high resolution satellite multi-temporal interferometry for landslide hazard detection in tropical environments: the case of Haiti

    NASA Astrophysics Data System (ADS)

    Wasowski, Janusz; Nutricato, Raffaele; Nitti, Davide Oscar; Bovenga, Fabio; Chiaradia, Maria Teresa; Piard, Boby Emmanuel; Mondesir, Philemon

    2015-04-01

    Synthetic aperture radar (SAR) multi-temporal interferometry (MTI) is one of the most promising satellite-based remote sensing techniques for fostering new opportunities in landslide hazard detection and assessment. MTI is attractive because it can provide very precise quantitative information on slow slope displacements of the ground surface over huge areas with limited vegetation cover. Although MTI is a mature technique, we are only beginning to realize the benefits of the high-resolution imagery that is currently acquired by the new generation radar satellites (e.g., COSMO-SkyMed, TerraSAR-X). In this work we demonstrate the potential of high resolution X-band MTI for wide-area detection of slope instability hazards even in tropical environments that are typically very harsh (eg. coherence loss) for differential interferometry applications. This is done by presenting an example from the island of Haiti, a tropical region characterized by dense and rapidly growing vegetation, as well as by significant climatic variability (two rainy seasons) with intense precipitation events. Despite the unfavorable setting, MTI processing of nearly 100 COSMO-SkyMed (CSK) mages (2011-2013) resulted in the identification of numerous radar targets even in some rural (inhabited) areas thanks to the high resolution (3 m) of CSK radar imagery, the adoption of a patch wise processing SPINUA approach and the presence of many man-made structures dispersed in heavily vegetated terrain. In particular, the density of the targets resulted suitable for the detection of some deep-seated and shallower landslides, as well as localized, very slow slope deformations. The interpretation and widespread exploitation of high resolution MTI data was facilitated by Google EarthTM tools with the associated high resolution optical imagery. Furthermore, our reconnaissance in situ checks confirmed that MTI results provided useful information on landslides and marginally stable slopes that can represent a

  8. Snowpack spatial and temporal variability assessment using SMP high-resolution penetrometer

    NASA Astrophysics Data System (ADS)

    Komarov, Anton; Seliverstov, Yuriy; Sokratov, Sergey; Grebennikov, Pavel

    2017-04-01

    This research is focused on study of spatial and temporal variability of structure and characteristics of snowpack, quick identification of layers based on hardness and dispersion values received from snow micro penetrometer (SMP). We also discuss the detection of weak layers and definition of their parameters in non-alpine terrain. As long as it is the first SMP tool available in Russia, our intent is to test it in different climate and weather conditions. During two separate snowpack studies in plain and mountain landscapes, we derived density and grain size profiles by comparing snow density and grain size from snowpits and SMP measurements. The first case study was MSU meteorological observatory test site in Moscow. SMP data was obtained by 6 consecutive measurements along 10 m transects with a horizontal resolution of approximately 50 cm. The detailed description of snowpack structure, density, grain size, air and snow temperature was also performed. By comparing this information, the detailed scheme of snowpack evolution was created. The second case study was in Khibiny mountains. One 10-meter-long transect was made. SMP, density, grain size and snow temperature data was obtained with horizontal resolution of approximately 50 cm. The high-definition profile of snowpack density variation was acquired using received data. The analysis of data reveals high spatial and temporal variability in snow density and layer structure in both horizontal and vertical dimensions. It indicates that the spatial variability is exhibiting similar spatial patterns as surface topology. This suggests a strong influence from such factors as wind and liquid water pressure on the temporal and spatial evolution of snow structure. It was also defined, that spatial variation of snowpack characteristics is substantial even within homogeneous plain landscape, while in high-latitude mountain regions it grows significantly.

  9. Vestibular Schwannoma Atypically Invading Temporal Bone

    PubMed Central

    Park, Soo Jeong; Yang, Na-Rae

    2015-01-01

    Vestibular schwannoma (VS) usually present the widening of internal auditory canal (IAC), and these bony changes are typically limited to IAC, not extend to temporal bone. Temporal bone invasion by VS is extremely rare. We report 51-year-old man who revealed temporal bone destruction beyond IAC by unilateral VS. The bony destruction extended anteriorly to the carotid canal and inferiorly to the jugular foramen. On histopathologic examination, the tumor showed typical benign schwannoma and did not show any unusual vascularity or malignant feature. Facial nerve was severely compressed and distorted by tumor, which unevenly eroded temporal bone in surgical field. Vestibular schwannoma with atypical invasion of temporal bone can be successfully treated with combined translabyrinthine and lateral suboccipiral approach without facial nerve dysfunction. Early detection and careful dissection of facial nerve with intraoperative monitoring should be considered during operation due to severe adhesion and distortion of facial nerve by tumor and eroded temporal bone. PMID:25932298

  10. High-resolution temporal analysis of deep subseafloor microbial communities inhabiting basement fluids

    NASA Astrophysics Data System (ADS)

    Jungbluth, S.; Lin, H. T.; Hsieh, C. C.; Rappe, M. S.

    2014-12-01

    The temporal variation in microbial communities inhabiting the anoxic, sediment-covered basaltic ocean basement is largely uncharacterized due to the inaccessible nature of the environment and difficulties associated with collection of samples from low-biomass microbial habitats. Here, a deep sea instrumented platform was employed on the Juan de Fuca Ridge in the summer of 2013 to collect 46 samples of basement fluids from the most recent generation of borehole observatories (U1362A and B), which feature multiple sampling horizons at a single location and fluid delivery lines manufactured using stainless steel or inert polytetrafluoroethylene (PTFE) parts. Included were three time-series deployments of the GEOmicrobe sled meant to resolve the fine-scale (i.e. hourly) temporal variation within in situ crustal microbial communities. Illumina technology was used to sequence small subunit ribosomal RNA (SSU rRNA) gene fragments from sediment, seawater, and subseafloor fluids. Similar to has been reported previously, basic differences in the three environments was observed. Fluid samples from depth horizons extending 30, 70, and ~200 meters sub-basement revealed differences in the observed microbial communities, indicating potential depth-specific zonation of microorganisms in the basaltic basement fluids. Extensive overlap between microorganisms collected from a single depth horizon but using two fluid delivery lines manufactured with different materials was observed, though some differences were also noted. Several archaeal (e.g. THSCG, MCG, MBGE, Archaeoglobus) and bacterial (e.g. Nitrospiraceae, OP8, KB1) lineages detected in previous years of basement fluid sampling nearby were found here, which further supports the notion that these microorganisms are stable residents of anoxic basaltic subseafloor fluids. Direct cell enumeration of samples collected from U1362A and U1362B revealed an elevated biomass compared to samples at these locations from previous years

  11. High-resolution temporal analysis reveals a functional timeline for the molecular regulation of cytokinesis.

    PubMed

    Davies, Tim; Jordan, Shawn N; Chand, Vandana; Sees, Jennifer A; Laband, Kimberley; Carvalho, Ana X; Shirasu-Hiza, Mimi; Kovar, David R; Dumont, Julien; Canman, Julie C

    2014-07-28

    To take full advantage of fast-acting temperature-sensitive mutations, thermal control must be extremely rapid. We developed the Therminator, a device capable of shifting sample temperature in ~17 s while simultaneously imaging cell division in vivo. Applying this technology to six key regulators of cytokinesis, we found that each has a distinct temporal requirement in the Caenorhabditis elegans zygote. Specifically, myosin-II is required throughout cytokinesis until contractile ring closure. In contrast, formin-mediated actin nucleation is only required during assembly and early contractile ring constriction. Centralspindlin is required to maintain division after ring closure, although its GAP activity is only required until just prior to closure. Finally, the chromosomal passenger complex is required for cytokinesis only early in mitosis, but not during metaphase or cytokinesis. Together, our results provide a precise functional timeline for molecular regulators of cytokinesis using the Therminator, a powerful tool for ultra-rapid protein inactivation.

  12. High-resolution temporal analysis reveals a functional timeline for the molecular regulation of cytokinesis

    PubMed Central

    Davies, Tim; Jordan, Shawn N.; Chand, Vandana; Sees, Jennifer A.; Laband, Kimberley; Carvalho, Ana; Shirasu-Hiza, Mimi; Kovar, David R.; Dumont, Julien; Canman, Julie C.

    2014-01-01

    Summary To take full advantage of fast-acting temperature-sensitive mutations, thermal control must be extremely rapid. We developed the Therminator, a device capable of shifting sample temperature in ~17s while simultaneously imaging cell division in vivo. Applying this technology to six key regulators of cytokinesis, we found that each has a distinct temporal requirement in the C. elegans zygote. Specifically, myosin-II is required throughout cytokinesis until contractile ring closure. In contrast, formin-mediated actin nucleation is only required during assembly and early contractile ring constriction. Centralspindlin is required to maintain division after ring closure, though its GAP activity is only required until just prior to closure. Finally, the Chromosomal Passenger Complex is required for cytokinesis only early in mitosis, but not during metaphase or cytokinesis. Together, our results provide a precise functional timeline for molecular regulators of cytokinesis using the Therminator, a powerful tool for ultra-rapid protein inactivation. PMID:25073157

  13. High-resolution (spatial and temporal) Hydrodynamic Modeling in the Lower Mississippi River Delta

    NASA Astrophysics Data System (ADS)

    Karadogan, E.; Danchuk, S.; Berger, C.; Brown, G.; Willson, C.

    2007-12-01

    The lower Mississippi River is a highly engineered system existing in one of the world's largest deltas. This system is subject to a variety of spatial and temporal forcings due to its large watershed (drains about 41% of the continental U.S.) and from the Gulf of Mexico. Future perturbations on this system are anticipated due to the impacts of global climate change (e.g., rising eustatic sea level, changes in weather patterns) and from proposed modifications to the system such as diversion structures aimed at providing freshwater nutrients and sediments to the rapidly degrading coastal wetlands. Numerical modeling will play a large role in improving our understanding and management of the system and the ability to properly design future structural features. These models will need to have the necessary spatial and temporal resolution to account for the many important processes in the river, the Gulf of Mexico, and in the wetland areas where small distributary channels will form and wetting/drying must be accounted for. This paper will investigate the ability of a 2D shallow water and sediment model to reproduce the complex distributary development associated with flow diversions into quiescent bays. A reach of the Lower Mississippi River from Point a la Hache to the Gulf of Mexico was used as a test domain to evaluate the performance and capabilities of the U.S. Army Corps of Engineers ADaptive Hydraulics (ADH) model. ADH is an unstructured finite element modeling system that includes unsaturated Richards' equations for groundwater, Navier Stokes for nonhydrostatic flow calculations, and Shallow Water equations. ADH conducts automated refinement and coarsening of the mesh based upon flow characteristics. In this case the 2D shallow water model is being used. It includes coupled flow and sedimentation. An unstructured mesh was developed for the study area which includes detailed bathymetry and topography from available survey data. The mesh is fine enough to capture

  14. A high resolution method for soil moisture mapping at large spatial and temporal scales

    NASA Astrophysics Data System (ADS)

    moreno, D.; Sayde, C.; Ochsner, T. E.; Sorin, C.; Selker, J. S.

    2013-12-01

    Soil moisture is a critical component of the planet's water budget, yet precise measurement of its dynamics across the critical scales of 0.1-1,000 m continues to be an area of great uncertainty. Here we present the preliminary results for a large scale installation of soil moisture quantification based on the work of Sayde et al. (2010) using actively heated fiber optic with a DTS system capable of soil moisture measurements at high spatial (reporting every 0.125 m) and temporal resolution (read as frequently as each 15 min)). The fiber optic (FO) sensing cables were installed in 2 sections: 1) a highly resolved multi-scale spiral 75m x 65m in size, 530 m total path length, and 2) a 770 m transect in the foot print of the cosmos cosmic ray probe installed at the site. In each of those 2 sections, the FO cables were deployed at 3 depths: 5, 10, and 15 cm. In this system the FO sensing system provides measurements of soil moisture at >39,000 locations simultaneously for each heat pulse. In addition, six soil monitoring stations along the fiber optic path were installed to provide additional validation and calibration of the DTS data. Finally, gravimetric soil moisture and soil thermal samplings were performed periodically to provide additional distributed validation and calibration of the DTS data. The ability of this DTS FO system to provide soil moisture measurements over four orders of magnitude in spatial scale (0.1 - 1,000m) will allow better understanding of the spatio-temporal variability in soil moisture in the field, which is essential to develop protocols for calibration and validation of large scale soil moisture remote sensing data (such as NASA airMOSS soil moisture air flights). The material is based upon work supported by NASA under award NNX12AP58G, with equipment and assistance also provided by CTEMPs.org with support from the National Science Foundation under Grant Number 1129003. Any opinions, findings, and conclusions or recommendations expressed

  15. Mapping temporal changes in connectivity using high-resolution aerial data and object based image analysis

    NASA Astrophysics Data System (ADS)

    Masselink, Rens; Anders, Niels; Keesstra, Saskia; Seeger, Manuel

    2014-05-01

    Within the field of geomorphology mapping has always been an important tool to interpret spatial and temporal distributions of phenomena and processes at the surface. In the field of connectivity however, although throughout the past decade many articles have been published, there are only very few that go into the mapping of connectivity. This study aimed at developing a new, automated method for mapping connectivity within agricultural catchments. The method, which is a combination of Object-Based Image Analysis (OBIA) and traditional geomorphological field mapping, was applied to two agricultural catchments in Navarre, Spain, both with an area of approximately 2 sq.km. An unmanned aerial vehicle (UAV) was used to take aerial photographs with a resolution of 6 cm, of which a DEM with a 12 cm resolution was created using structure-from-motion photogrammetry. Connectivity was mapped within the study areas using OBIA using a top down method, meaning that connectivity was mapped at different scale levels, starting at the largest scale. Firstly sub-catchments were automatically delineated, after which several characteristics and features that affect connectivity within the sub-catchments were classified, e.g. landuse, landslides, rills, gullies, riparian vegetation, changes in slope, ploughing direction etc. In two consecutive years (2013-2014) photographs were taken and connectivity of both catchments of both years will be compared. Future work will include a quantification of the mapped connectivity (highly connected years vs. low connected years), causes and consequences of these differences in connectivity, comparison to existing connectivity indices and comparison of mapped connectivity in sub-catchments and measured discharge.

  16. Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography

    NASA Astrophysics Data System (ADS)

    Kerckhofs, G.; Durand, M.; Vangoitsenhoven, R.; Marin, C.; van der Schueren, B.; Carmeliet, G.; Luyten, F. P.; Geris, L.; Vandamme, K.

    2016-10-01

    High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging.

  17. Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography

    PubMed Central

    Kerckhofs, G.; Durand, M.; Vangoitsenhoven, R.; Marin, C.; Van der Schueren, B.; Carmeliet, G.; Luyten, F. P.; Geris, L.; Vandamme, K.

    2016-01-01

    High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging. PMID:27759061

  18. Changes in bone macro- and microstructure in diabetic obese mice revealed by high resolution microfocus X-ray computed tomography.

    PubMed

    Kerckhofs, G; Durand, M; Vangoitsenhoven, R; Marin, C; Van der Schueren, B; Carmeliet, G; Luyten, F P; Geris, L; Vandamme, K

    2016-10-19

    High resolution microfocus X-ray computed tomography (HR-microCT) was employed to characterize the structural alterations of the cortical and trabecular bone in a mouse model of obesity-driven type 2 diabetes (T2DM). C57Bl/6J mice were randomly assigned for 14 weeks to either a control diet-fed (CTRL) or a high fat diet (HFD)-fed group developing obesity, hyperglycaemia and insulin resistance. The HFD group showed an increased trabecular thickness and a decreased trabecular number compared to CTRL animals. Midshaft tibia intracortical porosity was assessed at two spatial image resolutions. At 2 μm scale, no change was observed in the intracortical structure. At 1 μm scale, a decrease in the cortical vascular porosity of the HFD bone was evidenced. The study of a group of 8 week old animals corresponding to animals at the start of the diet challenge revealed that the decreased vascular porosity was T2DM-dependant and not related to the ageing process. Our results offer an unprecedented ultra-characterization of the T2DM compromised skeletal micro-architecture and highlight an unrevealed T2DM-related decrease in the cortical vascular porosity, potentially affecting the bone health and fragility. Additionally, it provides some insights into the technical challenge facing the assessment of the rodent bone structure using HR-microCT imaging.

  19. Basement membrane of mouse bone marrow sinusoids shows distinctive structure and proteoglycan composition: a high resolution ultrastructural study.

    PubMed

    Inoue, S; Osmond, D G

    2001-11-01

    Venous sinusoids in bone marrow are the site of a large-scale traffic of cells between the extravascular hemopoietic compartment and the blood stream. The wall of the sinusoids consists solely of a basement membrane interposed between a layer of endothelial cells and an incomplete covering of adventitial cells. To examine its possible structural specialization, the basement membrane of bone marrow sinusoids has now been examined by high resolution electron microscopy of perfusion-fixed mouse bone marrow. The basement membrane layer was discontinuous, consisting of irregular masses of amorphous material within a uniform 60-nm-wide space between apposing endothelial cells and adventitial cell processes. At maximal magnifications, the material was resolved as a random arrangement of components lacking the "cord network" formation seen in basement membranes elsewhere. Individual components exhibited distinctive ultrastructural features whose molecular identity has previously been established. By these morphological criteria, the basement membrane contained unusually abundant chondroitin sulfate proteoglycan (CSPG) revealed by 3-nm-wide "double tracks," and moderate amounts of both laminin as dense irregular coils and type IV collagen as 1-1.5-nm-wide filaments, together with less conspicuous amounts of amyloid P forming pentagonal frames. In contrast, 4.5-5-nm-wide "double tracks" characteristic of heparan sulfate proteoglycan (HSPG) were absent. The findings demonstrate that, in comparison with "typical" basement membranes in other tissues, the bone marrow sinusoidal basement membrane is uniquely specialized in several respects. Its discontinuous nature, lack of network organization, and absence of HSPG, a molecule that normally helps to maintain membrane integrity, may facilitate disassembly and reassembly of basement membrane material in concert with movements of adventitial cell processes as maturing hemopoietic cells pass through the sinusoidal wall: the

  20. Bilateral Asymmetry of Radius and Tibia Bone Macroarchitecture and Microarchitecture: A High-Resolution Peripheral Quantitative Computed Tomography Study.

    PubMed

    Hildebrandt, Erin M; Manske, Sarah L; Hanley, David A; Boyd, Steven K

    2016-01-01

    Studies assessing bone health often select the dominant or nondominant limb to scan, but not both, for efficiency reasons. New scanning technology allows 3-dimensional (3D) visualization of the microarchitecture in bone, but it is not well understood whether there are differences between the dominant and nondominant limbs. Using 3D high-resolution peripheral quantitative computed tomography (HR-pQCT), the aim of this study is to investigate the effect of limb dominance on bone macroarchitecture and microarchitecture. Healthy male and female participants (N=100; 59 female, 41 male), mean age 30.7±12.1 years, were scanned at both radii and tibiae using HR-pQCT. Hand and foot dominance were determined by the participant's self-report. Most participants were right hand dominant (94.0%) and right foot dominant (91.0%). In the pooled cohort, the dominant radius had significantly greater cortical area (2.11%; p=0.002) and failure load (3.00%; p=0.001). At the tibia, the dominant foot had significantly lower bone mineral density (-0.77%; p=0.042), cortical area (-1.05%; p=0.031), and thickness (-1.51%; p=0.017). For females, there were no differences at the radius, but at the tibia, the dominant side had greater cross-sectional area (1.03%; p=0.044). Our data suggest that dominance has a small yet significant effect on macroarchitecture at both the ultradistal radius and tibia but not microarchitecture. This work emphasizes that it is important to be consistent in the selection of either dominant or nondominant limbs for HR-pQCT cohort studies; however, in the case where the opposite limb needs to be scanned, there would be small differences in macroarchitecture and no significant differences in microarchitecture anticipated.

  1. Semi-automatic verification of cropland and grassland using very high resolution mono-temporal satellite images

    NASA Astrophysics Data System (ADS)

    Helmholz, Petra; Rottensteiner, Franz; Heipke, Christian

    2014-11-01

    Many public and private decisions rely on geospatial information stored in a GIS database. For good decision making this information has to be complete, consistent, accurate and up-to-date. In this paper we introduce a new approach for the semi-automatic verification of a specific part of the, possibly outdated GIS database, namely cropland and grassland objects, using mono-temporal very high resolution (VHR) multispectral satellite images. The approach consists of two steps: first, a supervised pixel-based classification based on a Markov Random Field is employed to extract image regions which contain agricultural areas (without distinction between cropland and grassland), and these regions are intersected with boundaries of the agricultural objects from the GIS database. Subsequently, GIS objects labelled as cropland or grassland in the database and showing agricultural areas in the image are subdivided into different homogeneous regions by means of image segmentation, followed by a classification of these segments into either cropland or grassland using a Support Vector Machine. The classification result of all segments belonging to one GIS object are finally merged and compared with the GIS database label. The developed approach was tested on a number of images. The evaluation shows that errors in the GIS database can be significantly reduced while also speeding up the whole verification task when compared to a manual process.

  2. Bi-Temporal Analysis of High-Resolution Satellite Imagery in Support of a Forest Conservation Program in Western Uganda

    NASA Astrophysics Data System (ADS)

    Thomas, N.; Lambin, E.; Audy, R.; Biryahwaho, B.; de Laat, J.; Jayachandran, S.

    2014-12-01

    Recent studies in land use sustainability have shown the conservation value of even small forest fragments in tropical smallholder agricultural regions. Forest patches provide important ecosystem services, wildlife habitat, and support human livelihoods. Our study incorporates multiple dates of high-resolution Quickbird imagery to map forest disturbance and regrowth in a smallholder agricultural landscape in western Uganda. This work is in support of a payments for ecosystem services (PES) project which uses a randomized controlled trial to assess the efficacy of PES for enhancing forest conservation. The research presented here details the remote sensing phase of this project. We developed an object-based methodology for detecting forest change from high-resolution imagery that calculates per class image reflectance and change statistics to determine persistent forest, non-forest, forest gain, and forest loss classes. The large study area (~ 2,400 km2) necessitated using a combination of 10 different image pairs of varying seasonality, sun angle, and viewing angle. We discuss the impact of these factors on mapping results. Reflectance data was used in conjunction with texture measures and knowledge-driven modeling to derive forest change maps. First, baseline Quickbird images were mapped into tree cover and non-tree categories based on segmented image objects and field inventory data, applied through a classification and regression tree (CART) classifier. Then a bi-temporal segmentation layer was generated and a series of object metrics from both image dates were extracted. A sample set of persistent forest objects that remained undisturbed was derived from the tree cover map and the red band (B3) change values. We calculated a variety of statistical indices for these persistent tree cover objects from the post- survey imagery to create maps of both forest cover loss and forest cover gain. These results are compared to visually assessed image objects in addition

  3. Evaluation of bone microarchitecture by high-resolution peripheral quantitative computed tomography (HR-pQCT) in hemodialysis patients.

    PubMed

    Negri, A L; Del Valle, E E; Zanchetta, M B; Nobaru, M; Silveira, F; Puddu, M; Barone, R; Bogado, C E; Zanchetta, J R

    2012-10-01

    Hemodialyzed patients have decreased bone strength not completely characterized. We evaluated bone microarchitecture in hemodialysis patients and compared it to that of subjects without renal disease by high-resolution peripheral quantitative computed tomography (HR-pQCT). Hemodialysis patients have a marked decreased in cortical density, thickness, and area with significant reduction in trabecular parameters that correlated with the severity of secondary hyperparathyroidism only in women. Although fracture risk is greatly increased in dialysis patients, the corresponding decreased in bone strength has not been completely characterized. We evaluated volumetric bone mineral density (vBMD) and bone microstructure by HR-pQCT at the distal radius and tibia in 50 hemodialyzed (HD) patients (30 females, mean age 53.2 ± 6 years and 20 males, mean age 59.1 ± 11 years) and 50 sex- and age-matched controls. At the distal radius HD, women showed a 29% reduction in total and trabecular density and trabecular bone volume fraction (p < 0.0001) compared to controls. Trabecular number was reduced by 25% (p < 0.0001), while trabecular separation was increased by 51%. Cortical thickness (-40%, p < 0.0001) and cortical area (-42%, p < 0.0001) were the parameters most reduced, while compact density was the parameter least reduced (-15%, p < 0.0001). Similar findings were found at the tibia. In HD men, HR-pQCT at the distal radius and tibia showed a reduction in volumetric density and microstructure parameters to a lesser extent than in women. In the hemodialyzed group, cortical thickness at the radius was negatively correlated with age both in women and men. At the distal radius and tibia, we found significant negative correlations between Log iPTH and total alkaline phosphatase with cortical vBMD(r = -0.48, p < 0.01; r = -0.69, p < 0.001), thickness (-0.37, p < 0.05; r = -0.60, p < 0.001), and area ((r = -0.43, p = 0

  4. Schneiderian papilloma of the temporal bone.

    PubMed

    van der Putten, Lisa; Bloemena, Elisabeth; Merkus, Paul; Hensen, Erik F

    2013-12-05

    Temporal bone Schneiderian papilloma may present as a primary tumour originating from the middle ear and mastoid process, or an extension from sinonasal disease. Both forms are rare, this being only the 18th case of primary temporal bone Schneiderian papilloma described to date. Although the current patient has remained disease free after excision of the papilloma, the reported recurrence rate is high, comparable to sinonasal Schneiderian papilloma with extrasinus extension. Malignant progression of primary Schneiderian papillomas is significantly reduced as compared to Schneiderian papillomas that extend from the sinonasal tract into the temporal bone. A positive human papilloma virus status, as found in this case, is a common feature and prognostic factor of sinonasal Schneiderian papilloma but an infrequent finding in temporal bone disease. Owing to the high recurrence rate, the risk of malignant progression and the absence of reliable prognostic markers, stringent follow-up consisting of otoscopy, nasendoscopy and imaging is essential.

  5. Agro-hydrology and multi-temporal high-resolution remote sensing: toward an explicit spatial processes calibration

    NASA Astrophysics Data System (ADS)

    Ferrant, S.; Gascoin, S.; Veloso, A.; Salmon-Monviola, J.; Claverie, M.; Rivalland, V.; Dedieu, G.; Demarez, V.; Ceschia, E.; Probst, J.-L.; Durand, P.; Bustillo, V.

    2014-12-01

    The growing availability of high-resolution satellite image series offers new opportunities in agro-hydrological research and modeling. We investigated the possibilities offered for improving crop-growth dynamic simulation with the distributed agro-hydrological model: topography-based nitrogen transfer and transformation (TNT2). We used a leaf area index (LAI) map series derived from 105 Formosat-2 (F2) images covering the period 2006-2010. The TNT2 model (Beaujouan et al., 2002), calibrated against discharge and in-stream nitrate fluxes for the period 1985-2001, was tested on the 2005-2010 data set (climate, land use, agricultural practices, and discharge and nitrate fluxes at the outlet). Data from the first year (2005) were used to initialize the hydrological model. A priori agricultural practices obtained from an extensive field survey, such as seeding date, crop cultivar, and amount of fertilizer, were used as input variables. Continuous values of LAI as a function of cumulative daily temperature were obtained at the crop-field level by fitting a double logistic equation against discrete satellite-derived LAI. Model predictions of LAI dynamics using the a priori input parameters displayed temporal shifts from those observed LAI profiles that are irregularly distributed in space (between field crops) and time (between years). By resetting the seeding date at the crop-field level, we have developed an optimization method designed to efficiently minimize this temporal shift and better fit the crop growth against both the spatial observations and crop production. This optimization of simulated LAI has a negligible impact on water budgets at the catchment scale (1 mm yr-1 on average) but a noticeable impact on in-stream nitrogen fluxes (around 12%), which is of interest when considering nitrate stream contamination issues and the objectives of TNT2 modeling. This study demonstrates the potential contribution of the forthcoming high spatial and temporal resolution

  6. Imaging innovations in temporal bone disorders.

    PubMed

    Corrales, C Eduardo; Fischbein, Nancy; Jackler, Robert K

    2015-04-01

    The development of new imaging techniques coupled with new treatment algorithms has created new possibilities in treating temporal bone diseases. This article provides an overview of recent imaging innovations that can be applied to temporal bone diseases. Topics covered include the role of magnetic resonance (MR) diffusion-weighted imaging in cholesteatomas and skull base epidermoids, whole-body molecular imaging in paragangliomas of the jugular foramen, and MR arterial spin labeling perfusion for dural arteriovenous fistulas and arteriovenous malformations.

  7. Comparison of computed tomography and pluridirectional tomography of the temporal bone

    SciTech Connect

    Lufkin, R.; Barni, J.J.; Glen, W.; Mancuso, A.; Canalis, R.; Hanafee, W.

    1982-06-01

    During pluridirectional tomography dense bone creates ghost shadows that simulate chronic disease and soft-tissue masses within the middle ear cavity. This effect was demonstrated in three dried skulls. Cholesteatomas were simulated in three more temporal bones with a mixture of 2% iodine in paraffin. Three different high-resolution computed tomographic scanners clearly demonstrated middle ear anatomy and the simulated soft-tissue masses in the skulls.

  8. A high-resolution temporal record of environmental changes in the Eastern Caribbean (Guadeloupe) from 40 to 10 ka BP

    NASA Astrophysics Data System (ADS)

    Royer, Aurélien; Malaizé, Bruno; Lécuyer, Christophe; Queffelec, Alain; Charlier, Karine; Caley, Thibaut; Lenoble, Arnaud

    2017-01-01

    In neotropical regions, fossil bat guano accumulated over time as laminated layers in caves, hence providing a high-resolution temporal record of terrestrial environmental changes. Additionally, cave settings have the property to preserve such organic sediments from processes triggered by winds (deflation, abrasion and sandblasting) and intense rainfall (leaching away). This study reports both stable carbon and nitrogen isotope compositions of frugivorous bat guano deposited in a well-preserved stratigraphic succession of Blanchard Cave on Marie-Galante, Guadeloupe. These isotopic data are discussed with regard to climate changes and its specific impact on Eastern Caribbean vegetation during the Late Pleistocene from 40 to 10 ka cal. BP. Guano δ13C values are higher than modern ones, suggesting noticeable vegetation changes. This provides also evidence for overall drier environmental conditions during the Pleistocene compared to today. Meanwhile, within this generally drier climate, shifts between wetter and drier conditions can be observed. Large temporal amplitudes in both δ13C and δ15N variations reaching up to 5.9‰ and 16.8‰, respectively, also indicate these oceanic tropical environments have been highly sensitive to regional or global climatic forcing. Stable isotope compositions of bat guano deposited from 40 to 35 ka BP, the Last Glacial Maximum and the Younger-Dryas reveal relatively wet environmental conditions whereas, at least from the end of the Heinrich event 1 and the Bølling period the region experienced drier environmental conditions. Nevertheless, when considering uncertainties in the model age, the isotopic record of Blanchard Cave show relatively similar variations with known proxy records from the northern South America and Central America, suggesting thus that the Blanchard Cave record is a robust proxy of past ITCZ migration. Teleconnections through global atmospheric pattern suggest that islands of the eastern Caribbean Basin could

  9. A Retrospective Review of Temporal Bone Imaging With Respect to Bone-Anchored Hearing Aid Placement.

    PubMed

    Baker, Aaron R; Fanelli, David G; Kanekar, Sangam; Isildak, Huseyin

    2017-01-01

    Current bone-anchored hearing aid (BAHA) guidelines recommend placement of the titanium implant 5 to 7 cm posterior to the ear canal. Previous studies show that bone conducted hearing is maximized the closer the transducer is to the cochlea. We aim to investigate the position of the sigmoid sinus with respect to BAHA implants to determine whether they may be safely placed closer to the ear canal in patients with chronic ear disease, enhancing the amplification available to the patient. We performed a retrospective review of high-resolution temporal bone computed tomographies (CTs), comparing multiple measurements between ears with chronic ear disease and normal controls. Images were obtained at a single academic medical center. Eighty patients (160 ears) with temporal bone CTs performed between 2006 and 2009 were measured. Patients with chronic ear disease were identified by international statistical classification of diseases and related health problems, revision 9 code and confirmation by review of the imaging. Measurements were made on axial CT slices from a point 1 cm posterior to the sigmoid sinus to the posterior margin of the external canal. The squamous temporal bone thickness was also measured at this point. Forty-seven patients (55 ears) had chronic ear disease. Distance from the posterior canal was significantly different between normal and diseased ears (36.3 mm versus 33.5 mm, p < 0.001). Squamous temporal bone thickness varied widely, and was similar between groups (6.9 mm versus 6.8 mm, p = 0.76). According to our data, titanium implants for bone-anchored hearing aids may be safely placed closer to the external canal than the current recommendations. This could allow for better transduction as well as sound localization in BAHA patients.

  10. Quality control for bone quality parameters affected by subject motion in high-resolution peripheral quantitative computed tomography.

    PubMed

    Pauchard, Yves; Liphardt, Anna-Maria; Macdonald, Heather M; Hanley, David A; Boyd, Steven K

    2012-06-01

    Subject motion during high-resolution peripheral quantitative computed tomography (HR-pQCT) causes image artifacts that affect morphological analysis of bone quality. The aim of our study was to determine effectiveness of techniques for quality control in the presence of motion in vivo including automated and manual approaches. First, repeatability of manual grading was determined within and between laboratories. Given proper training using a standardized scale and training images (provided by the manufacturer), we found that manual grading is suitable for repeatable image quality grading within and across sites (ICC>0.7). Both a new automated technique providing motion measures based on projection moments, and traditional manual grading (1=best, 5=worst) were subsequently used to assess subject data for motion in N=137 image pairs (scan/re-scan) from the Canadian Multicentre Osteoporosis Study (CaMos) Calgary cohort. High quality image pairs were selected and measurement precision was estimated by calculating the coefficient of variation (CV). Consistent with previous data, density parameters (e.g. total bone mineral density) are more robust than structural (e.g. trabecular number) or finite element parameters (e.g. failure load). To obtain acceptable measurement precision, images should not exceed a manual grading of 3 (on a scale from 1 to 5) or an automatic (ε(T)) grading of 1.2. Automatic and manual grading provide comparable quality control, but the advantage of the automated technique is its ability to provide a motion value at scan time (providing a basis for real time decision regarding re-scan requirements), and the assessment is objective. Notably, automatic motion measurement can be performed retrospectively based on original scan data, and is therefore well suited for multi-center studies as well as any research where objective quality control is paramount.

  11. High resolution structures of the bone morphogenetic protein type II receptor in two crystal forms: Implications for ligand binding

    SciTech Connect

    Mace, Peter D.; Cutfield, John F.; Cutfield, Sue M. . E-mail: sue.cutfield@otago.ac.nz

    2006-12-29

    BMPRII is a type II TGF-{beta} serine threonine kinase receptor which is integral to the bone morphogenetic protein (BMP) signalling pathway. It is known to bind BMP and growth differentiation factor (GDF) ligands, and has overlapping ligand specificity with the activin type II receptor, ActRII. In contrast to activin and TGF-{beta} type ligands, BMPs bind to type II receptors with lower affinity than type I receptors. Crystals of the BMPRII ectodomain were grown in two different forms, both of which diffracted to high resolution. The tetragonal form exhibited some disorder, whereas the entire polypeptide was seen in the orthorhombic form. The two structures retain the basic three-finger toxin fold of other TGF-{beta} receptor ectodomains, and share the main hydrophobic patch used by ActRII to bind various ligands. However, they present different conformations of the A-loop at the periphery of the proposed ligand-binding interface, in conjunction with rearrangement of a disulfide bridge within the loop. This particular disulfide (Cys94-Cys117) is only present in BMPRII and activin receptors, suggesting that it is important for their likely shared mode of binding. Evidence is presented that the two crystal forms represent ligand-bound and free conformations of BMPRII. Comparison with the solved structure of ActRII bound to BMP2 suggests that His87, unique amongst TGF-{beta} receptors, may play a key role in ligand recognition.

  12. A new temporal bone and cadaver head holder for temporal bone surgical technique training.

    PubMed

    Feng, Guodong; Lv, Wei; Tian, Xu; Wu, Haiyan; Gao, Zhiqiang

    2013-01-01

    To design a new temporal bone and cadaver head holder, overcoming the drawbacks of the bowl-type holder and other existing holders for dissection, and thereby benefiting training and research on temporal bone surgery. We designed and fabricated a novel holder with a horizontal arm that can be connected with an object holder specific for the temporal bone or a three-pin fixture specific for cadaver heads. A separate hand support helps to stabilize the hand during examinations on the temporal bone and skull base. The use of the temporal bone and cadaver head holder by 30 trainees during our temporal bone surgical technique courses held by the Department of Otolaryngology, Peking Union Medical College Hospital (PUMCH) worked better than other holders and saved laboratory time. It has become the standard equipment of the Temporal Bone Laboratory of PUMCH. The temporal bone and cadaver head holder we describe is compact, stable and easily adjustable. It offers considerable advantages to trainees. © 2013 S. Karger AG, Basel.

  13. Unsaturation level decreased in bone marrow fat of postmenopausal women with low bone density using high resolution magic angle spinning (HRMAS) (1)H NMR spectroscopy.

    PubMed

    Li, Xiaojuan; Shet, Keerthi; Xu, Kaipin; Rodríguez, Juan Pablo; Pino, Ana María; Kurhanewicz, John; Schwartz, Ann; Rosen, Clifford J

    2017-08-18

    There are increasing evidences suggesting bone marrow adiposity tissue (MAT) plays a critical role in affecting both bone quantity and quality. However, very limited studies that have investigated the association between the composition of MAT and bone mineral density (BMD). The goal of this study was to quantify MAT unsaturation profile of marrow samples from post-menopausal women using ex vivo high-resolution magic angle spinning (HRMAS) proton nuclear magnetic resonance ((1)H NMR) spectroscopy, and to investigate the relationship between MAT composition and BMD. Bone marrow samples were obtained by iliac crest aspiration during surgical procedures from 24 postmenopausal women (65-89years) who had hip surgery due to bone fracture or arthroplasty. Marrow fat composition parameters, in particular, unsaturation level (UL), mono-unsaturation level (MUL) and saturation level (SL), were quantified using HRMAS (1)H NMR spectroscopy. The patients were classified into three groups based on the DXA BMD T-scores: controls, osteopenia and osteoporosis. Marrow fat composition was compared between these three groups as well as between subjects with and without factures using ANOCOVA, adjusted for age. Subjects with lower BMD (n=17) had significantly lower MUL (P=0.003) and UL (P=0.039), and significantly higher SL (P=0.039) compared to controls (n=7). When separating lower BMD into osteopenia (n=9) and osteoporosis (n=8) groups, subjects with osteopenia had significantly lower MUL (P=0.002) and UL (P=0.010), and significantly higher SL (P=0.010) compared to healthy controls. No significant difference was observed between subjects with osteopenia and osteoporosis. Using HRMAS (1)H NMR, significantly lower unsaturation and significantly higher saturation levels were observed in the marrow fat of subjects with lower BMD. HRMAS (1)H NMR was shown to be a powerful tool for identifying novel MR markers of marrow fat composition that are associated with bone quality and potentially

  14. High-resolution fMRI of Content-sensitive Subsequent Memory Responses in Human Medial Temporal Lobe

    PubMed Central

    Preston, Alison R.; Bornstein, Aaron M.; Hutchinson, J. Benjamin; Gaare, Meghan E.; Glover, Gary H.; Wagner, Anthony D.

    2009-01-01

    The essential role of the medial temporal lobe (MTL) in long-term memory for individual events is well established, yet important questions remain regarding the mnemonic functions of the component structures that constitute the region. Within the hippocampus, recent functional neuroimaging findings suggest that formation of new memories depends on the den tate gyrus and the CA3 field, whereas the contribution of the subiculum may be limited to retrieval. During encoding, it has been further hypothesized that structures within MTL cortex contribute to encoding in a content-sensitive manner, whereas hippocampal structures may contribute to encoding in a more domain-general manner. In the current experiment, high-resolution fMRI techniques were utilized to assess novelty and subsequent memory effects in MTL subregions for two classes of stimuli—faces and scenes. During scanning, participants performed an incidental encoding (target detection) task with novel and repeated faces and scenes. Subsequent recognition memory was indexed for the novel stimuli encountered during scanning. Analyses revealed voxels sensitive to both novel faces and novel scenes in all MTL regions. However, similar percentages of voxels were sensitive to novel faces and scenes in perirhinal cortex, entorhinal cortex, and a combined region comprising the dentate gyrus, CA2, and CA3, whereas parahippocampal cortex, CA1, and subiculum demonstrated greater sensitivity to novel scene stimuli. Paralleling these findings, subsequent memory effects in perirhinal cortex were observed for both faces and scenes, with the magnitude of encoding activation being related to later memory strength, as indexed by a graded response tracking recognition confidence, whereas subsequent memory effects were scene-selective in parahippocampal cortex. Within the hippocampus, encoding activation in the subiculum correlated with subsequent memory for both stimulus classes, with the magnitude of encoding activation varying

  15. High Resolution Spatio Temporal Moments Analysis of Solute Migration Captured using Pre-clinical Medical Imaging Techniques

    NASA Astrophysics Data System (ADS)

    Dogan, M.; Moysey, S. M.; Powell, B. A.; DeVol, T. A.

    2016-12-01

    Advances in medical imaging technologies are continuously expanding the range of applications enabled within the earth sciences. While computed x-ray tomography (CT) scans have traditionally been used for investigating the structure of geologic materials, it is now possible to perform 3D time-lapse imaging of dynamic processes, such as monitoring the infiltration of water into a soil, with sub-millimeter resolution. Likewise, single photon emission computed tomography (SPECT) can provide information on the evolution of solute transport with spatial resolution on the order of a millimeter by tracking the migration of gamma-ray emitting isotopes like 99mTc and 111In. While these imaging techniques are revolutionizing our ability to look within porous media, techniques for the analysis of such rich and large data sets are limited. The spatial and temporal moments of a plume have long been used to provide quantitative measures to describe plume movement in a wide range of settings from the lab to field. Moment analysis can also be used to estimate the hydrologic properties of the porous media. In this research, we investigate the use of moments for analyzing a high resolution 4D SPECT data set collected during a 99mTc transport experiment performed in a heterogeneous column. The 4D nature of the data set makes it amenable to the use of data mining and pattern recognition methods, such as cluster analysis, to identify regions or zones within the data that exhibit abnormal or unexpected behaviors. We then compare anomalous features within the SPECT data to similar features identified within the CT image to relate the flow behavior to pore-scale structures, such as porosity differences and macropores. Such comparisons help to identify whether these features are good predictors of preferential transport. Likewise, we evaluate whether local analysis of moments can be used to infer apparent parameters governing non-conservative transport in a heterogeneous porous media, such

  16. A High-Resolution Study of Hippocampal and Medial Temporal Lobe Correlates of Spatial Context and Prospective Overlapping Route Memory

    PubMed Central

    Brown, Thackery I.; Hasselmo, Michael E.; Stern, Chantal E.

    2015-01-01

    When navigating our world we often first plan or retrieve an ideal route to our goal, avoiding alternative paths that lead to other destinations. The medial temporal lobe (MTL) has been implicated in processing contextual information, sequence memory, and uniquely retrieving routes that overlap or “cross paths.” However, the identity of subregions of the hippocampus and neighboring cortex that support these functions in humans remains unclear. The present study used high-resolution functional magnetic resonance imaging (hr-fMRI) in humans to test whether the CA3/DG hippocampal subfield and para-hippocampal cortex are important for processing spatial context and route retrieval, and whether the CA1 subfield facilitates prospective planning of mazes that must be distinguished from alternative overlapping routes. During hr-fMRI scanning, participants navigated virtual mazes that were well-learned from prior training while also learning new mazes. Some routes learned during scanning shared hallways with those learned during pre-scan training, requiring participants to select between alternative paths. Critically, each maze began with a distinct spatial contextual Cue period. Our analysis targeted activity from the Cue period, during which participants identified the current navigational episode, facilitating retrieval of upcoming route components and distinguishing mazes that overlap. Results demonstrated that multiple MTL regions were predominantly active for the contextual Cue period of the task, with specific regions of CA3/DG, parahippocampal cortex, and perirhinal cortex being consistently recruited across trials for Cue periods of both novel and familiar mazes. During early trials of the task, both CA3/DG and CA1 were more active for overlapping than non-overlapping Cue periods. Trial-by-trial Cue period responses in CA1 tracked subsequent overlapping maze performance across runs. Together, our findings provide novel insight into the contributions of MTL

  17. Pediatric temporal bone fractures: A case series.

    PubMed

    Waissbluth, S; Ywakim, R; Al Qassabi, B; Torabi, B; Carpineta, L; Manoukian, J; Nguyen, L H P

    2016-05-01

    Temporal bone fractures are relatively common findings in patients with head trauma. The aim of this study was to evaluate the characteristics of temporal bone fractures in the pediatric population. Retrospective case series. Tertiary care pediatric academic medical center. The medical records of patients aged 18 years or less diagnosed with a temporal bone fracture at the Montreal Children's Hospital from January 2000 to August 2014 were reviewed. Patient demographics, clinical presentation, mechanism of injury and complications were analyzed. Imaging studies and audiograms were also evaluated. Out of 323 patients presenting to the emergency department with a skull fracture, 61 presented with a temporal bone fracture. Of these, 5 presented with bilateral fractures. 47 patients had associated fractures, and 3 patients deceased. We observed a male to female ratio of 2.8:1, and the average age was 9.5 years. Motor vehicle accidents were the primary mechanism of injury (53%), followed by falls (21%) and bicycle or skateboard accidents (10%). The most common presenting signs included hemotympanum, decreased or loss of consciousness, facial swelling and nausea and vomiting. 8 patients had otic involvement on computed tomography scans, and 30 patients had documented hearing loss near the time of accident with a majority being conductive hearing loss. 17 patients underwent surgical management of intracranial pressure. In children, fractures of the temporal bone were most often caused by motor vehicle accidents and falls. It is common for these patients to have associated fractures. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  18. Spatial and Temporal Analysis of inundation and Freeze /Thaw states in Alaska Using High Resolution ALOS PALSAR Observations

    NASA Astrophysics Data System (ADS)

    Azarderakhsh, M.; McDonald, K. C.; Schroeder, R.; Steiner, N.; Podest, E.

    2013-12-01

    Monitoring freeze -thaw transitions and mapping the extent and dynamics of wetlands in high latitudes are critical to enhancing our knowledge about the biogeochemical transitions, carbon dynamics and prediction of boreal-arctic ecosystem. The upcoming Soil Moisture Active/Passive (SMAP) mission, scheduled for launch in October 2014, will have an L-band active / passive sensor package which will allow determination of soil moisture and the timing of landscape seasonal freeze/thaw states across the globe. In line with these ongoing efforts, this study aims to monitor inundation and Freeze and Thaw states in Alaska using Advanced Land Observing Satellite Phased Array L-Band SAR (ALOS PALSAR) ScanSAR observations. Four years of PALSAR measurements from 2007 to 2010 were acquired over the state of Alaska. Although wide-swath ScanSAR products, offer increased temporal coverage relative to standard narrow-beam SAR datasets, , they have a high variation of radar backscatter in across track because of the large swath width. We investigate the effect of incidence angle on radiometrically calibrated and terrain corrected ScanSAR data as a function of land surface (vegetation and roughness) and moisture content. These effects and their seasonal variation are used in classifiying inundated areas. The wetlands extent and inundation dynamics are crucial as they are an important component of the carbon cycle in Arctic regions. We apply pixel-based and object oriented-based classification methods to derive inundation maps during the thaw season. The dynamic inundation maps then are developed at 100m resolution. JERS and PALSAR Fine Beam mode based static wetlands map and Landsat Based land cover data (NLCD) are used to train and assess the classification at high resolution along with other ancillary data sets. The inundated areas obtained from wetland classification are then used to separate from other land cover types in F/T algorithm. We use a model based on Lambert's cosine

  19. Management of complication from temporal bone fractures.

    PubMed

    Cvorovic, Ljiljana; Ljiljana, Cvorovic; Jovanovic, Milan B; Markovic, Marko; Milutinovic, Zoran; Strbac, M

    2012-02-01

    The objective of the study is to review clinical findings and outcomes in patients with temporal bone fractures, and to show an incidence and management of complications. It is the retrospective clinical study and the study took place at tertiary referral center. Fifty-two patients with temporal bone fractures. Data were collected from patients' charts and clinical review. Patients were classified into five groups according to the CT scan. The primary endpoint of study was to show management of possible complication from temporal bone fractures and to analyze association with intracranial injuries. The second endpoint was to show incompleteness of traditionally classification of fracture type. Of the 52 patients with 54 fractures, 27 (50%) had longitudinal fractures, 4 (7.4%) had transverse fractures, 17 (31.5%) had temporal squama-mastoid fractures, 4 (7.4%) had mixed fractures and 2 (3.7%) had isolated meatal fracture. Fifty-eight percent of patients had at least one intracranial pathologic finding, of which 11% had two or more. Persistent conductive hearing loss was noted in 8 of 16 affected patients. The facial paralysis occurred in seven patients. One patient had benign paroxysmal positional vertigo developed 3 weeks after injury. In conclusion, rarely temporal bone fractures are isolated injures. The squama-mastoid fracture in most cases associated with intracranial injuries. Coordination between the neurosurgeon and otologist is essential in the care of such patients. Further large studies will be done to give a more complete classification of temporal bone fractures which will include all fracture patterns and predict clinical outcome.

  20. Comparison of temporal bone fractures in children and adults.

    PubMed

    Kang, Ho Min; Kim, Myung Gu; Hong, Seok Min; Lee, Ho Yun; Kim, Tae Hyun; Yeo, Seung Geun

    2013-05-01

    Contrary to our expectation, that the clinical characteristics of temporal bone fracture would differ in children and adults, we found that the two groups were similar. Most studies of temporal bone fractures have been performed in adults. To our knowledge, no study has investigated differences in temporal bone fractures in children and adults. We therefore investigated differences in temporal bone fractures in adults and children by examining the manifestations and clinical symptoms of temporal bone fractures in pediatric patients. The demographic and clinical characteristics were assessed in 32 children and 186 adults with temporal bone fractures. All patients underwent computed tomography of the temporal bone. Causes of fracture, gender distribution, manifestations of temporal bone fracture, and clinical symptoms were similar in adults and children (p > 0.05 each). Petrous fracture, ear fullness, dizziness, and tinnitus were significantly more frequent in adults than in children (p < 0.05 each).

  1. Convective rain cells: spatio-temporal characteristics, synoptic patterns and a high resolution synoptically conditioned weather generator

    NASA Astrophysics Data System (ADS)

    Peleg, Nadav; Morin, Efrat

    2014-05-01

    Information on rain cell features was extracted from high-resolution weather radar data for a total of 191,586 radar volume scans from 12 hydrological years. The convective rain cell features (i.e., cell area, rainfall intensity and cell orientation) were obtained using cell segmentation technique and cell tracking algorithm was used to analyze the changes of those features over time. Three synoptic types were defined for the study area (northen Israel), two extratropical winter lows: deep Cyprus low and a shallow low, and a tropical intrusion: Active Red Sea Trough. Empirical distributions were computed to describe the spatiotemporal characteristics of convective rain cells for these synoptic systems. Those empirical distributions were used for the development of the HiReS-WG (high-resolution synoptically conditioned weather generator). This weather generator is a stochastic model that generates high resolution rainfall fields (5 min and 0.25 km2). The WG is composed of four modules: the synoptic generator, the motion vector generator, the convective rain cell generator and the low-intensity rainfall generator. The weather generator was evaluated for annual rain depth, season timing, wet-/dry-period duration, rain-intensity distributions and spatial correlations using 300 years of simulated rainfall data. It was found that the weather generator well-represented the above properties compared to radar and rain-gauge observations from the studied region. The HiReS-WG is a good tool to study catchments' hydrological responses to variations in rainfall, especially small- to medium-size catchments, and it can also be linked to climate models to force the prevailing synoptic conditions.

  2. Application of the Minkowski functionals in 3D to high-resolution MR images of trabecular bone: prediction of the biomechanical strength by nonlinear topological measures

    NASA Astrophysics Data System (ADS)

    Boehm, Holger F.; Link, Thomas M.; Monetti, Roberto A.; Mueller, Dirk; Rummeny, Ernst J.; Newitt, David; Majumdar, Sharmila; Raeth, Christoph W.

    2004-05-01

    Multi-dimensional convex objects can be characterized with respect to shape, structure, and the connectivity of their components using a set of morphological descriptors known as the Minkowski functionals. In a 3D Euclidian space, these correspond to volume, surface area, mean integral curvature, and the Euler-Poincaré characteristic. We introduce the Minkowski functionals to medical image processing for the morphological analysis of trabecular bone tissue. In the context of osteoporosis-a metabolic disorder leading to a weakening of bone due to deterioration of micro-architecture-the structure of bone increasingly gains attention in the quantification of bone quality. The trabecular architecture of healthy cancellous bone consists of a complex 3D system of inter-connected mineralised elements whereas in osteoporosis the micro-structure is dominated by gaps and disconnections. At present, the standard parameter for diagnosis and assessment of fracture risk in osteoporosis is the bone mineral density (BMD) - a bulk measure of mineralisation irrespective of structural texture characteristics. With the development of modern imaging modalities (high resolution MRI, micro-CT) with spatial resolutions allowing to depict individual trabeculae bone micro-architecture has successfully been analysed using linear, 2- dimensional structural measures adopted from standard histo-morphometry. The preliminary results of our study demonstrate that due to the complex - i.e. the non-linear - network of trabecular bone structures non-linear measures in 3D are superior to linear ones in predicting mechanical properties of trabecular bone from structural information extracted from high resolution MR image data.

  3. [Computed tomography and magnetic resonance imaging of congenital abnormalities of the temporal bone].

    PubMed

    Czerny, C; Gstöttner, W; Imhof, H

    2003-03-01

    Congenital abnormalities of the temporal bone are mostly accompanied by conductive or sensori-neural hearing loss. Before any therapeutic procedures are done high resolution CT (HRCT) and magnetic resonance imaging (MRI) should be performed to establish the correct diagnosis and to plan the potentially surgical intervention. HRCT best depicts osseous changes especially those of the external auditory canal and the middle ear containing the ossicles and the osseous structures of the temporal bone and the petrous bone containing the inner ear. MRI excellently shows soft tissue changes of the inner ear especially on the high resolution 3DT2-weighted sequences which give a superb contrast between the nerves and the cerebro-spinal fluid. Malformations of the external auditory canal consists of aplasia or hypoplasia and those of the middle ear range form extreme hypoplasia or aplasia to very mild deformations of the ossicles. Malformations of the inner ear also range form complete aplasia to very mild hypoplasia of the organs of the inner ear as well as malformations concerning the nerves in the internal auditory canal range from aplasia to hypoplasia. Malformations of the temporal bone can either occur isolated or in combination in which malformations of the external and middle ear may be accompanied by those of the inner ear. Furthermore, malformations of the temporal bone may also occur in otofacial, otocervical or otoskeletal syndromes. These syndromes may be accompanied by certain malformations of the temporal bone. HRCT and MRI are both excellent methods to depict congenital abnormalities of the temporal bone and of the inner ear and should be used as complementary methods because HRCT best depicts osseous changes and MRI superbly depicts soft tissue changes. Both methods are important to establish the correct diagnosis to plan the therapeutic procedures.

  4. Non-invasive predictors of human cortical bone mechanical properties: T(2)-discriminated H NMR compared with high resolution X-ray.

    PubMed

    Horch, R Adam; Gochberg, Daniel F; Nyman, Jeffry S; Does, Mark D

    2011-01-21

    Recent advancements in magnetic resonance imaging (MRI) have enabled clinical imaging of human cortical bone, providing a potentially powerful new means for assessing bone health with molecular-scale sensitivities unavailable to conventional X-ray-based diagnostics. To this end, (1)H nuclear magnetic resonance (NMR) and high-resolution X-ray signals from human cortical bone samples were correlated with mechanical properties of bone. Results showed that (1)H NMR signals were better predictors of yield stress, peak stress, and pre-yield toughness than were the X-ray derived signals. These (1)H NMR signals can, in principle, be extracted from clinical MRI, thus offering the potential for improved clinical assessment of fracture risk.

  5. Massive acquired cholesteatoma of the temporal bone.

    PubMed

    Wright, J L; Colman, B H; Connor, A F

    1976-03-01

    Nine patients with massive acquired cholesteatoma of the temporal bone were treated by radical mastoidectomy, facial nerve decompression, and excision of the inner ear. The commonest presenting symptoms were otorrhea and deafness, but otalgia, vertigo, external swelling and facial nerve palsies were also seen. Polytomography was helpful in assessing the degree of bone erosion preoperatively. The large cavity present following cholesteatoma excision was partially obliterated by a superiorly based temporalis muscle pedicle which helped to seal the internal auditory meatus and prevented the development of a cerebral hernia. Those patients with preoperative facial nerve palsies showed evidence of nerve degeneration and had incomplete recovery at a one year follow-up.

  6. A quantitative method for the evaluation of three-dimensional structure of temporal bone pneumatization

    PubMed Central

    Hill, Cheryl A.; Richtsmeier, Joan T.

    2010-01-01

    Temporal bone pneumatization has been included in lists of characters used in phylogenetic analyses of human evolution. While studies suggest that the extent of pneumatization has decreased over the course of human evolution, little is known about the processes underlying these changes or their significance. In short, reasons for the observed reduction and the potential reorganization within pneumatized spaces are unknown. Technological limitations have limited previous analyses of pneumatization in extant and fossil species to qualitative observations of the extent of temporal bone pneumatization. In this paper, we introduce a novel application of quantitative methods developed for the study of trabecular bone to the analysis of pneumatized spaces of the temporal bone. This method utilizes high-resolution X-ray computed tomography (HRXCT) images and quantitative software to estimate three-dimensional parameters (bone volume fractions, anisotropy, and trabecular thickness) of bone structure within defined units of pneumatized spaces. We apply this approach in an analysis of temporal bones of diverse but related primate species, Gorilla gorilla, Pan troglodytes, Homo sapiens, and Papio hamadryas anubis, to illustrate the potential of these methods. In demonstrating the utility of these methods, we show that there are interspecific differences in the bone structure of pneumatized spaces, perhaps reflecting changes in the localized growth dynamics, location of muscle attachments, encephalization, or basicranial flexion. PMID:18715622

  7. Bilateral Facial Paralysis Caused by Temporal Bone Fracture: A Case Report

    PubMed Central

    Ghiasi, Samad; Banaei, Mehdi

    2016-01-01

    Introduction Although bilateral facial nerve palsy is a rare condition, its etiology is more detectable than the unilateral type. A temporal bone fracture is one cause of bilateral facial nerve palsy, contributing in 3% of the cases. Case Presentation Here, we report the case of a 35-year-old man complaining of bilateral incomplete eye closure, two weeks after a closed head injury caused by a motor vehicle accident. Conclusions The high resolution computed tomography findings revealed a bilateral temporal bone fracture line, which extended to the fallopian canal. With regard to treatment, near complete recovery was obvious after two weeks of treatment with oral corticosteroids. Overall, bilateral facial palsy is hard to diagnose; therefore, clinical suspicion and the early detection of facial nerve injuries is necessary for good nerve recovery in temporal bone fractures. PMID:27679786

  8. Analysis of high resolution temperature observation for spatial and temporal soil moisture variation in an unstable slope

    NASA Astrophysics Data System (ADS)

    Krzeminska, D. M.; Steele-Dunne, S. C.; Rutten, M. M.; Bogaard, T. A.; Sailhac, P.; Géraud, Y.

    2009-04-01

    Hydrological processes control the behaviour of many unstable slopes hence their importance for landslide hazard is generally accepted. The unsaturated zone buffers precipitation and moisture conditions of this zone affect distribution, intensity and time delay of ground water recharges. Therefore, high resolution monitoring of hydrological features of the near surface soil layer is necessary, especially when studying rainfall triggered landslides. The aim of our research is to test the use of temperature as a tracer for soil moisture distribution. Recently, much research attention has been given to the temperature measurements as surveying technique in the hydrological studies. We applied so-called distributed temperature sensing (DTS) fibre optic cable to obtain high resolution soil temperature observation. Two cables were installed in the soil (approximately at 25 cm depth) at different location within the landslide to measure the near surface soil temperature with 2 m spatial resolution and 3 minutes time step. We will present the result obtained during the field campaigns that took place at Super-Sauze landslide, French Alps. Phase and amplitude shifts of temperature signal will be analyzed and related to the soil moisture dynamics. Moreover, the temperature signals will be confronted with the coupled soil heat flux and soil moisture flux model. Furthermore, the temperature data set will be used to evaluate the time variation of the soil moisture content and position of ground water level based on the determination of the soil thermal parameters fluctuation. Our work will discuss the applicability of distributed temperature sensing for hydrological studies, especially to monitor soil moisture distribution and development of preferential flow paths in a landslide area.

  9. Primary Ameloblastoma of the Temporal Bone.

    PubMed

    Košec, Andro; Ajduk, Jakov; Ries, Mihael; Trotić, Robert

    2017-06-01

    Ameloblastoma is a locally aggressive tumor derived from odontogenic epithelium. Although benign, its clinical behavior can often exhibit malignant characteristics. It is marked by slow and persistent growth with infiltration of adjacent tissues. Almost 70% occur in the mandible in patients older than 30 years. Recurrence of ameloblastoma from inadequate treatment is frequent. Because of its slow growth, recurrences can present decades after primary surgery. A primary ameloblastoma in an area outside the mandibular, maxillary, and infratemporal fossa regions has not been described in detail to date, with only 1 possible case mentioned in the literature. The authors present a case of primary temporal bone ameloblastoma in a 17-year-old boy. The tumor originated in the left mastoid, infiltrated the lateral semicircular canal, facial nerve, and cochlea, and adhered to the sigmoid sinus and posterior cranial fossa dura. Although invasion of multiple structures in the infratemporal fossa and temporal bone leads to variable disease presentation, this case is unique because the first symptom of disease was sudden and recurring unilateral sensorineural hearing loss. Surgery required transection of the facial nerve. Histopathology confirmed primary temporal bone ameloblastoma. The difficulties in achieving wide surgical margins, diagnostics, and further management are addressed. Copyright © 2017 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  10. In vivo application of 3D-line skeleton graph analysis (LSGA) technique with high-resolution magnetic resonance imaging of trabecular bone structure.

    PubMed

    Pothuaud, Laurent; Newitt, David C; Lu, Ying; MacDonald, Brian; Majumdar, Sharmila

    2004-05-01

    Over the last several years magnetic resonance (MR) imaging has emerged as a means of measuring in vivo 3D trabecular bone structure. In particular, MR based diagnosis could be used to complement standard bone mineral density (BMD) methods for assessing osteoporosis and evaluating longitudinal changes. The aim of this study was to demonstrate the feasibility of using the 3D-LSGA technique for the evaluation of trabecular bone structure of high-resolution MR images, particularly for assessing longitudinal changes, in vivo. First, the reproducibility of topological 3D-LSGA based measurements was evaluated in a set of seven volunteers, and coefficients of variations ranged from 3.5% to 6%. Second, high-resolution MR images of the radius in 30 postmenopausal women from a placebo controlled drug study (Idoxifene), divided into placebo ( n=9) and treated ( n=21) groups, were obtained at baseline (BL) and after 1 year of treatment (follow-up, FU). In addition, dual X-ray absorptiometry (DXA) measures of BMD were obtained in the distal radius. Standard morphological measurements based on the mean intercept length (MIL) technique as well as 3D-LSGA based measurements were applied to the 3D MR images. Significant changes from BL to FU were detected, in the treated group, using the topological 3D-LSGA based measurements, morphological measures of volume of connected trabeculae and App Tb.N from MIL analysis. The duration of the study was short, and the number of patients remaining in the study was small, hence these results cannot be interpreted with regard to a true therapeutic response. Furthermore, the site (wrist) and the drug (idoxifene) are not optimal for follow-up study. However, this paper demonstrated the feasibility of using 3D-LSGA based evaluation coupled with in vivo high-resolution MR imaging as a complementary approach for the monitoring of trabecular bone changes in individual subjects.

  11. Non-invasive bone competence analysis by high-resolution pQCT: an in vitro reproducibility study on structural and mechanical properties at the human radius.

    PubMed

    Mueller, Thomas L; Stauber, Martin; Kohler, Thomas; Eckstein, Felix; Müller, Ralph; van Lenthe, G Harry

    2009-02-01

    Osteoporosis is defined as a skeletal disorder characterized by compromised bone strength. Bone strength depends, among others, on bone density, bone geometry and its internal architecture. With the recent introduction of a new generation high-resolution 3D peripheral quantitative computed tomography (HR-pQCT) system, direct quantification of structural bone parameters has become feasible. Furthermore, it has recently been demonstrated that bone mechanical competence can be derived from HR-pQCT based micro-finite element modeling (microFE). However, reproducibility data for HR-pQCT-derived mechanical indices is not well-known. Therefore, the aim of this study was to quantify reproducibility of HR-pQCT-derived indices. We measured 14 distal formalin-fixed cadaveric forearms three times and analyzed three different regions for each measurement. For each region cortical and trabecular parameters were determined. Reproducibility was assessed with respect to precision error (PE) and intraclass correlation coefficient (ICC). Reproducibility values were found to be best in all three regions for the full bone compartment with an average PE of 0.79%, followed by the cortical compartment (PE=1.19%) and the trabecular compartment with an average PE of 2.31%. The mechanical parameters showed similar reproducibility (PE=0.48%-2.93% for bone strength and stiffness, respectively). ICC showed a very high reproducibility of subject-specific measurements, ranging from 0.982 to 1.000, allowing secure identification of individual donors ranging from healthy to severely osteoporotic subjects. From these in vitro results we conclude that HR-pQCT derived morphometric and mechanical parameters are highly reproducible such that differences in bone structure and strength can be detected with a reproducibility error smaller than 3%; hence, the technique has a high potential to become a tool for detecting bone quality and bone competence of individual subjects.

  12. Arabidopsis Defense against Botrytis cinerea: Chronology and Regulation Deciphered by High-Resolution Temporal Transcriptomic Analysis[C][W

    PubMed Central

    Windram, Oliver; Madhou, Priyadharshini; McHattie, Stuart; Hill, Claire; Hickman, Richard; Cooke, Emma; Jenkins, Dafyd J.; Penfold, Christopher A.; Baxter, Laura; Breeze, Emily; Kiddle, Steven J.; Rhodes, Johanna; Atwell, Susanna; Kliebenstein, Daniel J.; Kim, Youn-sung; Stegle, Oliver; Borgwardt, Karsten; Zhang, Cunjin; Tabrett, Alex; Legaie, Roxane; Moore, Jonathan; Finkenstadt, Bärbel; Wild, David L.; Mead, Andrew; Rand, David; Beynon, Jim; Ott, Sascha; Buchanan-Wollaston, Vicky; Denby, Katherine J.

    2012-01-01

    Transcriptional reprogramming forms a major part of a plant’s response to pathogen infection. Many individual components and pathways operating during plant defense have been identified, but our knowledge of how these different components interact is still rudimentary. We generated a high-resolution time series of gene expression profiles from a single Arabidopsis thaliana leaf during infection by the necrotrophic fungal pathogen Botrytis cinerea. Approximately one-third of the Arabidopsis genome is differentially expressed during the first 48 h after infection, with the majority of changes in gene expression occurring before significant lesion development. We used computational tools to obtain a detailed chronology of the defense response against B. cinerea, highlighting the times at which signaling and metabolic processes change, and identify transcription factor families operating at different times after infection. Motif enrichment and network inference predicted regulatory interactions, and testing of one such prediction identified a role for TGA3 in defense against necrotrophic pathogens. These data provide an unprecedented level of detail about transcriptional changes during a defense response and are suited to systems biology analyses to generate predictive models of the gene regulatory networks mediating the Arabidopsis response to B. cinerea. PMID:23023172

  13. Investigation of double tropopause spatial and temporal global variability utilizing High Resolution Dynamics Limb Sounder temperature observations

    NASA Astrophysics Data System (ADS)

    Peevey, Tanya R.; Gille, John C.; Randall, Cora E.; Kunz, Anne

    2012-01-01

    This study examines the seasonal variation of the double tropopause (DT) using data from the High Resolution Dynamics Limb Sounder. The combination of high data density and high vertical resolution available with this satellite instrument allows for the detailed analysis of fine-scale structures such as the DT. The spatial distribution of DT frequency is examined for all seasons from 2005 to 2007. Global analysis of this distribution reveals that DTs have a strong tendency to follow the zonal wind pattern and are present all year over the Andes. Moreover, during Northern Hemisphere winter/spring, there is a 15% decrease in the DT frequency over the eastern Pacific and western Atlantic, two regions of wave breaking produced from a weakening of the zonal flow. Significant DT thickness values are also present over these regions, but are found to extend further poleward than the corresponding frequency pattern. A time series of DT frequencies is analyzed and shows an increase in daily frequencies during 2006 that highlights the interannual variability of this thermal structure. For the first time, DT duration is investigated in the extratropics utilizing a Hovmöller diagram of DT frequency. This representation highlights two preferred regions of formation, the Pacific and Atlantic. The slope of the feature gives it a speed of 18 m/s in the Northern Hemisphere and a slightly faster speed for the Southern Hemisphere. These speeds and the corresponding structures highlight a potential connection between upper tropospheric waves and DTs.

  14. High-resolution imaging-guided electroencephalography source localization: temporal effect regularization incorporation in LORETA inverse solution

    NASA Astrophysics Data System (ADS)

    Boughariou, Jihene; Zouch, Wassim; Slima, Mohamed Ben; Kammoun, Ines; Hamida, Ahmed Ben

    2015-11-01

    Electroencephalography (EEG) and magnetic resonance imaging (MRI) are noninvasive neuroimaging modalities. They are widely used and could be complementary. The fusion of these modalities may enhance some emerging research fields targeting the exploration better brain activities. Such research attracted various scientific investigators especially to provide a convivial and helpful advanced clinical-aid tool enabling better neurological explorations. Our present research was, in fact, in the context of EEG inverse problem resolution and investigated an advanced estimation methodology for the localization of the cerebral activity. Our focus was, therefore, on the integration of temporal priors to low-resolution brain electromagnetic tomography (LORETA) formalism and to solve the inverse problem in the EEG. The main idea behind our proposed method was in the integration of a temporal projection matrix within the LORETA weighting matrix. A hyperparameter is the principal fact for such a temporal integration, and its importance would be obvious when obtaining a regularized smoothness solution. Our experimental results clearly confirmed the impact of such an optimization procedure adopted for the temporal regularization parameter comparatively to the LORETA method.

  15. Spatial-Temporal Dynamics of High-Resolution Animal Networks: What Can We Learn from Domestic Animals?

    PubMed

    Chen, Shi; Ilany, Amiyaal; White, Brad J; Sanderson, Michael W; Lanzas, Cristina

    2015-01-01

    Animal social network is the key to understand many ecological and epidemiological processes. We used real-time location system (RTLS) to accurately track cattle position, analyze their proximity networks, and tested the hypothesis of temporal stationarity and spatial homogeneity in these networks during different daily time periods and in different areas of the pen. The network structure was analyzed using global network characteristics (network density), subgroup clustering (modularity), triadic property (transitivity), and dyadic interactions (correlation coefficient from a quadratic assignment procedure) at hourly level. We demonstrated substantial spatial-temporal heterogeneity in these networks and potential link between indirect animal-environment contact and direct animal-animal contact. But such heterogeneity diminished if data were collected at lower spatial (aggregated at entire pen level) or temporal (aggregated at daily level) resolution. The network structure (described by the characteristics such as density, modularity, transitivity, etc.) also changed substantially at different time and locations. There were certain time (feeding) and location (hay) that the proximity network structures were more consistent based on the dyadic interaction analysis. These results reveal new insights for animal network structure and spatial-temporal dynamics, provide more accurate descriptions of animal social networks, and allow more accurate modeling of multiple (both direct and indirect) disease transmission pathways.

  16. Spatial-Temporal Dynamics of High-Resolution Animal Networks: What Can We Learn from Domestic Animals?

    PubMed Central

    Chen, Shi; Ilany, Amiyaal; White, Brad J.; Sanderson, Michael W.; Lanzas, Cristina

    2015-01-01

    Animal social network is the key to understand many ecological and epidemiological processes. We used real-time location system (RTLS) to accurately track cattle position, analyze their proximity networks, and tested the hypothesis of temporal stationarity and spatial homogeneity in these networks during different daily time periods and in different areas of the pen. The network structure was analyzed using global network characteristics (network density), subgroup clustering (modularity), triadic property (transitivity), and dyadic interactions (correlation coefficient from a quadratic assignment procedure) at hourly level. We demonstrated substantial spatial-temporal heterogeneity in these networks and potential link between indirect animal-environment contact and direct animal-animal contact. But such heterogeneity diminished if data were collected at lower spatial (aggregated at entire pen level) or temporal (aggregated at daily level) resolution. The network structure (described by the characteristics such as density, modularity, transitivity, etc.) also changed substantially at different time and locations. There were certain time (feeding) and location (hay) that the proximity network structures were more consistent based on the dyadic interaction analysis. These results reveal new insights for animal network structure and spatial-temporal dynamics, provide more accurate descriptions of animal social networks, and allow more accurate modeling of multiple (both direct and indirect) disease transmission pathways. PMID:26107251

  17. Micro-finite element analysis applied to high-resolution MRI reveals improved bone mechanical competence in the distal femur of female pre-professional dancers.

    PubMed

    Chang, G; Rajapakse, C S; Diamond, M; Honig, S; Recht, M P; Weiss, D S; Regatte, R R

    2013-04-01

    Micro-finite element analysis applied to high-resolution (0.234-mm length scale) MRI reveals greater whole and cancellous bone stiffness, but not greater cortical bone stiffness, in the distal femur of female dancers compared to controls. Greater whole bone stiffness appears to be mediated by cancellous, rather than cortical bone adaptation. The purpose of this study was to compare bone mechanical competence (stiffness) in the distal femur of female dancers compared to healthy, relatively inactive female controls. This study had institutional review board approval. We recruited nine female modern dancers (25.7±5.8 years, 1.63±0.06 m, 57.1±4.6 kg) and ten relatively inactive, healthy female controls matched for age, height, and weight (32.1±4.8 years, 1.6±0.04 m, 55.8±5.9 kg). We scanned the distal femur using a 7-T MRI scanner and a three-dimensional fast low-angle shot sequence (TR/TE=31 ms/5.1 ms, 0.234 mm×0.234 mm×1 mm, 80 slices). We applied micro-finite element analysis to 10-mm-thick volumes of interest at the distal femoral diaphysis, metaphysis, and epiphysis to compute stiffness and cross-sectional area of whole, cortical, and cancellous bone, as well as cortical thickness. We applied two-tailed t-tests and ANCOVA to compare groups. Dancers demonstrated greater whole and cancellous bone stiffness and cross-sectional area at all locations (p<0.05). Cortical bone stiffness, cross-sectional area, and thickness did not differ between groups (>0.08). At all locations, the percent of intact whole bone stiffness for cortical bone alone was lower in dancers (p<0.05). Adjustment for cancellous bone cross-sectional area eliminated significant differences in whole bone stiffness between groups (p>0.07), but adjustment for cortical bone cross-sectional area did not (p<0.03). Modern dancers have greater whole and cancellous bone stiffness in the distal femur compared to controls. Elevated whole bone stiffness in dancers may be mediated via cancellous, rather

  18. Micro-finite element analysis applied to high-resolution MRI reveals improved bone mechanical competence in the distal femur of female pre-professional dancers

    PubMed Central

    Rajapakse, C. S.; Diamond, M.; Honig, S.; Recht, M. P.; Weiss, D. S.; Regatte, R. R.

    2013-01-01

    Summary Micro-finite element analysis applied to high-resolution (0.234-mm length scale) MRI reveals greater whole and cancellous bone stiffness, but not greater cortical bone stiffness, in the distal femur of female dancers compared to controls. Greater whole bone stiffness appears to be mediated by cancellous, rather than cortical bone adaptation. Introduction The purpose of this study was to compare bone mechanical competence (stiffness) in the distal femur of female dancers compared to healthy, relatively inactive female controls. Methods This study had institutional review board approval. We recruited nine female modern dancers (25.7± 5.8 years, 1.63±0.06 m, 57.1±4.6 kg) and ten relatively inactive, healthy female controls matched for age, height, and weight (32.1±4.8 years, 1.6±0.04 m, 55.8±5.9 kg). We scanned the distal femur using a 7-T MRI scanner and a three-dimensional fast low-angle shot sequence (TR/TE= 31 ms/5.1 ms, 0.234 mm×0.234 mm×1 mm, 80 slices). We applied micro-finite element analysis to 10-mm-thick volumes of interest at the distal femoral diaphysis, metaphysis, and epiphysis to compute stiffness and cross-sectional area of whole, cortical, and cancellous bone, as well as cortical thickness. We applied two-tailed t-tests and ANCOVA to compare groups. Results Dancers demonstrated greater whole and cancellous bone stiffness and cross-sectional area at all locations (p< 0.05). Cortical bone stiffness, cross-sectional area, and thickness did not differ between groups (>0.08). At all locations, the percent of intact whole bone stiffness for cortical bone alone was lower in dancers (p<0.05). Adjustment for cancellous bone cross-sectional area eliminated significant differences in whole bone stiffness between groups (p>0.07), but adjustment for cortical bone cross-sectional area did not (p<0.03). Conclusions Modern dancers have greater whole and cancellous bone stiffness in the distal femur compared to controls. Elevated whole bone stiffness

  19. Magnetic resonance imaging of trabecular and cortical bone in mice: comparison of high resolution in vivo and ex vivo MR images with corresponding histology.

    PubMed

    Weber, Michael H; Sharp, Jonathan C; Latta, Peter; Sramek, Milos; Hassard, H Thomas; Orr, F William

    2005-01-01

    Measurements of bone morphometry and remodeling have been shown to reflect bone strength and can be used to diagnose degenerative bone disease. In this study, in vivo and ex vivo magnetic resonance imaging (MRI) techniques to assess trabecular and cortical bone properties have been compared to each other and to histology as a novel means for the quantification of bone. Femurs of C57Bl/6 mice were examined both in vivo and ex vivo on an 11.7 T MRI scanner, followed by histologic processing and morphometry. A thresholding analysis technique was applied to the MRI images to generate contour lines and to delineate the boundaries between bone and marrow. Using MRI, an optimal correlation with histology was obtained with an in vivo longitudinal sectioned short echo time gradient-echo versus an in vivo long echo time spin-echo sequence or an ex vivo pulse sequence. Gradient-echo images were acquired with a maximum in-plane resolution of 35 microm. Our results demonstrated that in both the in vivo and ex vivo data sets, the percent area of marrow increases and percent area of trabecular bone and cortical bone thickness decreases moving from the epiphyseal growth plate to the diaphysis. These changes, observed with MRI, correlate with the histological data. Investigations using in vivo MRI gradient-echo sequences consistently gave the best correlation with histology. Our quantitative evaluation using both ex vivo and in vivo MRI was found to be an effective means to visualize non-invasively the normal variation in trabecular and cortical bone as compared to a histological "gold standard" The experiments validated in vivo MRI as a potential high resolution technique for investigating both soft tissue, such as marrow, and bone without radiation exposure.

  20. Serial Scanning and Registration of High Resolution Quantitative Computed Tomography Volume Scans for the Determination of Local Bone Density Changes

    NASA Technical Reports Server (NTRS)

    Whalen, Robert T.; Napel, Sandy; Yan, Chye H.

    1996-01-01

    Progress in development of the methods required to study bone remodeling as a function of time is reported. The following topics are presented: 'A New Methodology for Registration Accuracy Evaluation', 'Registration of Serial Skeletal Images for Accurately Measuring Changes in Bone Density', and 'Precise and Accurate Gold Standard for Multimodality and Serial Registration Method Evaluations.'

  1. Abbreviated breast magnetic resonance protocol: Value of high-resolution temporal dynamic sequence to improve lesion characterization.

    PubMed

    Oldrini, Guillaume; Fedida, Benjamin; Poujol, Julie; Felblinger, Jacques; Trop, Isabelle; Henrot, Philippe; Darai, Emile; Thomassin-Naggara, Isabelle

    2017-10-01

    To evaluate the added value of ULTRAFAST-MR sequence to an abbreviated FAST protocol in comparison with FULL protocol to distinguish benign from malignant lesions in a population of women, regardless of breast MR imaging indication. From March 10th to September 22th, 2014, we retrospectively included a total of 70 consecutive patients with 106 histologically proven lesions (58 malignant and 48 benign) who underwent breast MR imaging for preoperative breast staging (n=38), high-risk screening (n=7), problem solving (n=18), and nipple discharge (n=4) with 12 time resolved imaging of contrast kinetics (TRICKS) acquisitions during contrast inflow interleaved in a regular high-resolution dynamic MRI protocol (FULL protocol). Two readers scored MR exams as either positive or negative and described significant lesions according to Bi-RADS lexicon with a TRICKS images (ULTRAFAST), an abbreviated protocol (FAST) and all images (FULL protocol). Sensitivity, specificity, positive and negative predictive values, and accuracy were calculated for each protocol and compared with McNemar's test. For all readers, the combined FAST-ULTRAFAST protocol significantly improved the reading with a specificity of 83.3% and 70.8% in comparison with FAST protocol or FULL protocol, respectively, without change in sensitivity. By adding ULTRAFAST protocol to FAST protocol, readers 1 and 2 were able to correctly change the diagnosis in 22.9% (11/48) and 10.4% (5/48) of benign lesions, without missing any malignancy, respectively. Both interpretation and image acquisition times for combined FAST-ULTRAFAST protocol and FAST protocol were shorter compared to FULL protocol (p<0.001). Compared to FULL protocol, adding ULTRAFAST to FAST protocol improves specificity, mainly in correctly reclassifying benign masses and reducing interpretation and acquisition time, without decreasing sensitivity. Copyright © 2017 Elsevier B.V. All rights reserved.

  2. Analyses of the temporal and spatial structures of heavy rainfall from a catalog of high-resolution radar rainfall fields

    NASA Astrophysics Data System (ADS)

    Thorndahl, Søren; Smith, James A.; Baeck, Mary Lynn; Krajewski, Witold F.

    2014-07-01

    In this paper, we develop a storm catalog of heavy rainfall events for a region centered on the Milwaukee, Wisconsin WSR-88D (Weather Surveillance Radar - 1988 Doppler) radar. The study region includes portions of southern Wisconsin, northern Illinois and Lake Michigan. The long-term objective of this study is to develop rainfall frequency analysis methods based on a storm catalog of major rain events. The specific objectives of this study are to develop a long-term catalog of high-resolution radar rainfall fields and characterize key features of the space-time variability of rainfall. The research questions that underlie these objectives are: 1) What are the spatial heterogeneities of rainfall over the study region for major flood-producing storm systems? 2) What are the key elements of storm evolution that control the scale-dependent properties of extreme rainfall? The storm catalog contains a record of the 50 “largest” storm days during the 1996-2011 observation period. We show that mean rainfall for the 50 largest storm days exhibits pronounced spatial heterogeneity with a broad maximum in western Wisconsin and a minimum in the eastern portion of the study region over Lake Michigan. We also show that there is a narrow line of maximum mean rainfall extending from west to east along the Wisconsin-Illinois border. This feature is tied to a maximum in the probability of daily rainfall exceeding 100 mm. There are characteristic elements to the storm life cycle of heavy rainfall days that relate to size, structure and evolution of heavy rainfall. Extreme rainfall is also linked with severe weather (tornados, large hail and damaging wind). The diurnal cycle of rainfall for heavy rain days is characterized by an early peak in the largest rainfall rates, an afternoon-evening peak in rain area exceeding 25 mm h- 1 and development of a large stratiform rain area during the night and early morning.

  3. Feasibility study for reconstructing the spatial-temporal structure of TIDs from high-resolution backscatter ionograms

    NASA Astrophysics Data System (ADS)

    Nickisch, L. J.; Fridman, Sergey; Hausman, Mark; San Antonio, Geoffrey S.

    2016-05-01

    Over-the-horizon radar (OTHR) utilizes the reflective "sky wave" property of the ionosphere for high-frequency radiowaves to illuminate targets at ranges extending to several thousand kilometers. However, the ionospheric "mirror" is not static but exhibits geographic, diurnal, seasonal, and solar cycle variations. NorthWest Research Associates has developed an ionospheric data assimilation capability called Global Positioning Satellite Ionospheric Inversion (GPSII; pronounced "gypsy") that allows real-time modeling of the ionospheric structure for the purpose of accurate coordinate registration (CR; OTHR geolocation). However, the ionosphere is routinely subjected to traveling ionospheric disturbances (TIDs), and the deflection of HF sky wave signals by unmodeled TIDs remains a troubling source of CR errors (tens of kilometers). Traditional OTHR tools for ionospheric sounding (vertical and backscatter ionograms) do not resolve the fine spatial structure associated with TIDs. The collection of backscatter ionograms using the full aperture of the OTHR was recently demonstrated, thus providing enhanced resolution in radar azimuth in comparison with conventional OTHR backscatter soundings that utilize only a fraction of the OTHR receiver array. Leading edges of such backscatter ionograms demonstrate prominent spatial features associated with TIDs. We investigate the feasibility of recovering TID perturbations of ionospheric electron density from high-resolution backscatter ionograms. We incorporated a model of naturally occurring TIDs into a numerical ray tracing code that allows the generation of synthetic OTHR data. We augmented GPSII to assimilate time series of full-aperture backscatter ionogram leading edge data. Results of the simulation show that GPSII is able to reproduce the TID structure used to generate the backscatter ionograms reasonably well.

  4. Human-Impacted Waters: Temporal Evolution of Human Proximity to Rivers from Global High Resolution Nighttime Lights

    NASA Astrophysics Data System (ADS)

    Montanari, A.; Ceola, S.; Laio, F.

    2015-12-01

    The human presence close to streams and rivers is known to have consistently increased worldwide, therefore introducing dramatic anthropogenic and environmental changes. However, a spatio-temporal detailed analysis is missing to date. In this analysis, we propose a novel method to quantify the temporal evolution and the spatial distribution of the anthropogenic presence along streams and rivers and in their immediate proximity at the global scale and at a high spatial resolution (i.e., nearly 1 km at the equator). We use satellite images of nocturnal lights, available as yearly snapshots from 1992 to 2013, and identify five distinct distance classes from the river network position. Our results show a temporal enhancement of human presence across the considered distance classes. In particular, we observed a higher human concentration in the vicinity of the river network, even though the frequency distribution of human beings in space has not significantly changed in the last two decades. Our results prove that fine scale remotely sensed data, as nightlights, may provide new perspectives in water science, improving our understanding of the human impact on water resources and water-related environments.

  5. High Resolution Measurement of Rhizosphere Priming Effects and Temporal Variability of CO2 Fluxes under Zea Mays

    NASA Astrophysics Data System (ADS)

    Splettstößer, T.; Pausch, J.

    2016-12-01

    Plant induced increase of soil organic matter turnover rates contribute to carbon emissions in agricultural land use systems. In order to better understand these rhizosphere priming effects, we conducted an experiment, which enabled us to monitor CO2 fluxes under zea mays plants with high resolution. The experiment was conducted in a climate chamber where the plants were grown in thin, tightly sealed boxes for 40 days and CO2 efflux from soil was measured twice a day. 13C-CO2 was introduced to allow differentiation between plant and soil derived CO2.This enabled us to monitor root respiration and soil organic matter turnover in the early stages of plant growth and to highlight changes in soil CO2 emissions and priming effects between day and night. The measurements were conducted with a PICARRO G2131-I δ13C high-precision isotopic CO2 Analyzer (PICARRO INC.) utilizing an automated valve system governed by a CR1000 data logger (Campbell Scientific). After harvest roots and shoots were analyzed for 13C content. Microbial biomass, root length density and enzymatic activities in soil were measured and linked to soil organic matter turnover rates. In order to visualize the spatial distribution of carbon allocation to the root system a few plants were additionally labeled with 14C and 14C distribution was monitored by 14C imaging of the root systems over 4 days. Based on the 14C distribution a grid was chosen and the soil was sampled from each square of the grid to investigate the impact of carbon allocation hotspots on enzymatic activities and microbial biomass. First initial results show an increase of soil CO2 efflux in the night periods, whereby the contribution of priming is not fully analyzed yet. Additionally, root tips were identified as hotspots of short term carbon allocation via 14C imaging and an in increase in microbial biomass could be measured in this regions. The full results will be shown at AGU 2016.

  6. Audiometric Outcomes in Pediatric Temporal Bone Trauma.

    PubMed

    Schell, Amy; Kitsko, Dennis

    2016-01-01

    To characterize pediatric temporal bone trauma, focusing on audiometric outcomes. Case series with chart review. Tertiary care children's hospital. Cases were reviewed of children (<18 years) presenting over a 3-year period with computed tomography-proven temporal bone fracture and audiology examination. All scans were read by a neuroradiologist and reviewed by a pediatric otolaryngologist. Demographics, fracture pattern, and audiometric data were recorded. Fifty-eight patients (60 fractures) met inclusion criteria. The majority (93%) were otic capsule-sparing fractures. The types and severity of hearing loss were significantly different between the 2 fracture patterns. Based on pure-tone average, all otic capsule-violating fractures had abnormal initial audiograms; 75% of these losses were severe. Approximately half (54%) of otic capsule-sparing fractures had abnormal initial audiograms; a majority were mild losses (85%). All classifiable losses in otic capsule-violating cases were of mixed type, whereas the majority (75%) of losses in otic capsule-sparing cases were conductive. Regardless of classification, 72% of patients with otic capsule-sparing fractures and initially abnormal audiograms improved to normal levels at a mean of 48 days posttrauma; this increased to 83% when only conductive losses were considered. Hearing loss type and severity differ in otic capsule-sparing and otic capsule-violating temporal bone fractures. A majority of children with otic capsule-sparing fractures and associated hearing loss improve to normal levels in about 6 weeks, especially if the original loss is classified as solely conductive. Children who do not improve within this time frame may warrant early investigation into surgically correctable causes. © American Academy of Otolaryngology-Head and Neck Surgery Foundation 2015.

  7. The Multi-Temporal Database of High Resolution Stereo Camera (HRSC) and Planetary Images of Mars (MUTED): A Tool to Support the Identification of Surface Changes

    NASA Astrophysics Data System (ADS)

    Erkeling, G.; Luesebrink, D.; Hiesinger, H.; Reiss, D.; Jaumann, R.

    2015-10-01

    Image data transmitted to Earth by Martian spacecraft since the 1970s, for example by Mariner and Viking, Mars Global Surveyor (MGS), Mars Express (MEx) and the Mars Reconnaissance Orbiter (MRO) showed, that the surface of Mars has changed dramatically and actually is continually changing [e.g., 1-8]. The changes are attributed to a large variety of atmospherical, geological and morphological processes, including eolian processes [9,10], mass wasting processes [11], changes of the polar caps [12] and impact cratering processes [13]. The detection of surface changes in planetary image data is closely related to the spatial and temporal availability of images in a specific region. While previews of the images are available at ESA's Planetary Science Archive (PSA), through the NASA Planetary Data System (PDS) and via other less frequently used databases, there is no possibility to quickly and conveniently see the spatial and temporal availability of HRSC images and other planetary image data in a specific region, which is important to detect the surface changes that occurred between two or more images. In addition, it is complicated to get an overview of the image quality and label information for images covering the same area. However, the investigation of surface changes represents a key element in martian research and has implications for the geologic, morphologic and climatic evolution of Mars. In order to address these issues, we developed the "Multi- Temporal Database of High Resolution Stereo Camera (HRSC) Images" (MUTED), which represents a tool for the identification of the spatial and multi-temporal coverage of planetary image data from Mars. Scientists will be able to identify the location, number, and time range of acquisition of overlapping HRSC images. MUTED also includes images of other planetary image datasets such as those of the Context Camera (CTX), the Mars Orbiter Camera (MOC), the Thermal Emission Imaging System (THEMIS), and the High Resolution

  8. Temporal bone arrangements in turtles: an overview.

    PubMed

    Werneburg, Ingmar

    2012-06-01

    The temporal region of turtles is characterized by significant anatomical diversity. Turtles show a pure anapsid morphotype that exhibits various different marginal reductions known as emarginations. As a result of this diversity, turtles can be taken as a model by which to understand the processes that may have resulted in the highly debated anatomy of the amniote temporal region in general. In this review on almost forgotten literature, I summarize ten potential factors that may act on the skull to shape the temporal region of turtles. These are: (1) phylogenetic constraints, (2) skull weights, (3) type of food, (4) skull dimensions, (5) muscle bulging, (6) ear anatomy and jaw muscle bending mechanisms, (7) extent and nature of muscle attachment sites, (8) internal forces within the jaw adductor chamber, (9) environmental pressure, and (10) neck bending mechanisms. Particular focus is laid on the interrelationship of the jaw musculature and the dermatocranial armour, which were assumed to influence each other to a certain degree. In the literature, cranial dimensions were assumed to influence temporal bone formation within major tetrapod groups. Among these, turtles seem to represent a kind of intermixture, a phenomenon that may be reflected in their specific anatomy. The references presented should be understood as product of the scientific environment in which they developed and the older literature does not always insist current empirical demands. However, the intuitive and creative ideas and the comprehensive anatomical considerations of these authors may inspire future studies in several fields related to this topic.

  9. Postnatal temporal bone ontogeny in Pan, Gorilla, and Homo, and the implications for temporal bone ontogeny in Australopithecus afarensis.

    PubMed

    Terhune, Claire E; Kimbel, William H; Lockwood, Charles A

    2013-08-01

    Assessments of temporal bone morphology have played an important role in taxonomic and phylogenetic evaluations of fossil taxa, and recent three-dimensional analyses of this region have supported the utility of the temporal bone for testing taxonomic and phylogenetic hypotheses. But while clinical analyses have examined aspects of temporal bone ontogeny in humans, the ontogeny of the temporal bone in non-human taxa is less well documented. This study examines ontogenetic allometry of the temporal bone in order to address several research questions related to the pattern and trajectory of temporal bone shape change during ontogeny in the African apes and humans. We further apply these data to a preliminary analysis of temporal bone ontogeny in Australopithecus afarensis. Three-dimensional landmarks were digitized on an ontogenetic series of specimens of Homo sapiens, Pan troglodytes, Pan paniscus, and Gorilla gorilla. Data were analyzed using geometric morphometric methods, and shape changes throughout ontogeny in relation to size were compared. Results of these analyses indicate that, despite broadly similar patterns, African apes and humans show marked differences in development of the mandibular fossa and tympanic portions of the temporal bone. These findings indicate divergent, rather than parallel, postnatal ontogenetic allometric trajectories for temporal bone shape in these taxa. The pattern of temporal bone shape change with size exhibited by A. afarensis showed some affinities to that of humans, but was most similar to extant African apes, particularly Gorilla. Copyright © 2013 Wiley Periodicals, Inc.

  10. Investigation of spatial resolution and temporal performance of SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout) with integrated electrostatic focusing

    NASA Astrophysics Data System (ADS)

    Scaduto, David A.; Lubinsky, Anthony R.; Rowlands, John A.; Kenmotsu, Hidenori; Nishimoto, Norihito; Nishino, Takeshi; Tanioka, Kenkichi; Zhao, Wei

    2014-03-01

    We have previously proposed SAPHIRE (scintillator avalanche photoconductor with high resolution emitter readout), a novel detector concept with potentially superior spatial resolution and low-dose performance compared with existing flat-panel imagers. The detector comprises a scintillator that is optically coupled to an amorphous selenium photoconductor operated with avalanche gain, known as high-gain avalanche rushing photoconductor (HARP). High resolution electron beam readout is achieved using a field emitter array (FEA). This combination of avalanche gain, allowing for very low-dose imaging, and electron emitter readout, providing high spatial resolution, offers potentially superior image quality compared with existing flat-panel imagers, with specific applications to fluoroscopy and breast imaging. Through the present collaboration, a prototype HARP sensor with integrated electrostatic focusing and nano- Spindt FEA readout technology has been fabricated. The integrated electron-optic focusing approach is more suitable for fabricating large-area detectors. We investigate the dependence of spatial resolution on sensor structure and operating conditions, and compare the performance of electrostatic focusing with previous technologies. Our results show a clear dependence of spatial resolution on electrostatic focusing potential, with performance approaching that of the previous design with external mesh-electrode. Further, temporal performance (lag) of the detector is evaluated and the results show that the integrated electrostatic focusing design exhibits comparable or better performance compared with the mesh-electrode design. This study represents the first technical evaluation and characterization of the SAPHIRE concept with integrated electrostatic focusing.

  11. High resolution spatio-temporal mapping of NO2 pollution for estimating personal exposures of the Dutch population

    NASA Astrophysics Data System (ADS)

    Soenario, Ivan; Helbich, Marco; Schmitz, Oliver; Strak, Maciek; Hoek, Gerard; Karssenberg, Derek

    2017-04-01

    Air pollution has been associated with adverse health effects (e.g., cardiovascular and respiration diseases) in the urban environments. Therefore, the assessment of people's exposure to air pollution is central in epidemiological studies. The estimation of exposures on an individual level can be done by combining location information across space and over time with spatio-temporal data on air pollution concentrations. When detailed information on peoples' space-time paths (e.g. commuting patterns calculated by means of spatial routing algorithms or tracked through GPS) and peoples' major activity locations (e.g. home location, work location) are available, it is possible to calculate more precise personal exposure levels depending on peoples' individual space-time mobility patterns. This requires air pollution values not only at a high level of spatial accuracy and high temporal granularity but such data also needs to be available on a nation-wide scale. As current data is seriously limited in this respect, we introduce a novel data set of NO2 levels across the Netherlands. The provided NO2 concentrations are accessible on hourly timestamps on a 5 meter grid cell resolution for weekdays and weekends, and each month of the year. We modeled a single Land Use Regression model using a five year average of NO2 data from the Dutch NO2 measurement network consisting of N=46 sampling locations distributed over the country. Predictor variables for this model were selected in a data-driven manner using an Elastic Net and Best Subset Selection procedure from 70 candidate predictors including traffic, industry, infrastructure and population-based variables. Subsequently, to model NO2 for each time scale (hour, week, month), the LUR coefficients were fitted using the NO2 data, aggregated per time scale. Model validation was grounded on independent data collected in an ad hoc measurement campaign. Our results show a considerable difference in urban concentrations between

  12. Temporal bone anatomy in Panthera tigris

    NASA Astrophysics Data System (ADS)

    Walsh, Edward J.; Ketten, Darlene R.; Arruda, Julie; Armstrong, Douglas L.; Curro, Thomas; Simmons, Lee G.; Wang, Lily M.; McGee, Joann

    2004-05-01

    Preliminary findings suggest that members of Panthera tigris subspecies may rely on low-frequency acoustic cues when communicating with conspecifics either in the field or in captivity. This view is supported by the observation that individuals are sensitive to tone bursts in the 300-500-Hz range and produce significant acoustic energy in an overlapping frequency band in the case of close encounter roars. Other utterances within the vocal repertoire of tigers also contain, and are often dominated by, low frequency acoustic energy that can extend into the infrasonic range. Efforts to determine temporal bone correlates of P. tigris bioacoustical features were recently initiated using computerized tomography to assess key aspects of middle and inner ear morphology from a small set of adult Siberian tigers (P. tigris altaica) and one neonate. Obvious peripheral auditory specializations were not observed and structures comprising the auditory periphery were consistent with the anatomical character of felids generally. Although cochlear dimensions appeared to be adultlike, or nearly so, in the case of the neonate, other temporal bone features were grossly immature. The relationship between acoustic sensitivity, the spectral character of a subset of close encounter calls and cochlear dimensions will be considered.

  13. Application of high resolution pQCT analysis for the assessment of a bone lesion: a technical note.

    PubMed

    Rubinacci, A; Tresoldi, D; Villa, I; Rizzo, G; Gaudio, D; De Angelis, D; Gibelli, D; Cattaneo, C

    2015-01-01

    Peripheral quantitative computed tomography (pQCT) has found new fields of application in bone medicine, but none of them concerns the forensic practice. This study exposes the potential of pQCT applied to a penetrating lesion in a vertebral body. A pQCT scanner was used for the measurements (XCT Research SA+; Stratec Medizintechnik GmbH, Pforzheim, Germany). A more precise reconstruction of the path of the lesion within the trabecular bone was reached, with more details concerning the morphological characteristics of the lesion inside the vertebral body, and the elaboration of a 3D model was created, which allowed the operator to define the volume of the lack of tissues related to the lesion. The application of pQCT scan proved to be a potentially useful tool for the assessment of bone lesions, although further studies are needed in order to verify its applicability to forensic context.

  14. Temporal measurement and analysis of high-resolution spectral signatures of plants and relationships to biophysical characteristics

    NASA Astrophysics Data System (ADS)

    Bostater, Charles R., Jr.; Rebbman, Jan; Hall, Carlton; Provancha, Mark; Vieglais, David

    1995-11-01

    Measurements of temporal reflectance signatures as a function of growing season for sand live oak (Quercus geminata), myrtle oak (Q. myrtifolia, and saw palmetto (Serenoa repens) were collected during a two year study period. Canopy level spectral reflectance signatures, as a function of 252 channels between 368 and 1115 nm, were collected using near nadir viewing geometry and a consistent sun illumination angle. Leaf level reflectance measurements were made in the laboratory using a halogen light source and an environmental optics chamber with a barium sulfate reflectance coating. Spectral measurements were related to several biophysical measurements utilizing optimal passive ambient correlation spectroscopy (OPACS) technique. Biophysical parameters included percent moisture, water potential (MPa), total chlorophyll, and total Kjeldahl nitrogen. Quantitative data processing techniques were used to determine optimal bands based on the utilization of a second order derivative or inflection estimator. An optical cleanup procedure was then employed that computes the double inflection ratio (DIR) spectra for all possible three band combinations normalized to the previously computed optimal bands. These results demonstrate a unique approach to the analysis of high spectral resolution reflectance signatures for estimation of several biophysical measures of plants at the leaf and canopy level from optimally selected bands or bandwidths.

  15. A high resolution spatial and temporal multiple Doppler analysis of a microburst and its application to aircraft flight simulation

    NASA Technical Reports Server (NTRS)

    Elmore, K. L.; Mccarthy, J.; Frost, W.; Chang, H. P.

    1986-01-01

    Multiple Doppler radar data collected during the Joint Airport Weather Studies (JAWS) Project is used to synthesize the three-dimensional wind in the region of a microburst. The particular microburst used in this study is the strongest one to date for which three-dimensional winds have been recovered. As a diagnostic tool, a six-DOF numerical aircraft model having characteristics similar to 727 series aircraft is used to investigate jet transport aircraft response to observed microburst winds during simulated approaches and departures. Simple pilot control laws are used to adjust thrust, pitch, roll, and yaw so as to maintain given approach or departure parameters. Generally, when horizontal wind shear along the approach or departure path is 0.01/s or greater, the model is unable to maintain the desired approach path and suffers a significant reduction in climb performance during a go-around or departure. Although the mean wind shear along a path gives a good qualitative measure of the wind shear threat to a jet transport, different paths with similar mean shears can yield markedly different results, as do the same paths through the microburst at different times. These findings are a direct consequence of the fine temporal and spatial scale of microburst winds. During any given modeled aircraft traverse through the region of highest horizontal shear, time variations in the microburst wind field are shown to have an insignificant effect on the modeled flight path. This is because the traverse period is short (30 s) compared to the lifetime of a microburst (300-600 s).

  16. Sensitivity of Honeybee Hygroreceptors to Slow Humidity Changes and Temporal Humidity Variation Detected in High Resolution by Mobile Measurements

    PubMed Central

    Tichy, Harald; Kallina, Wolfgang

    2014-01-01

    The moist cell and the dry cell on the antenna of the male honeybee were exposed to humidities slowly rising and falling at rates between –1.5%/s and +1.5%/s and at varying amplitudes in the 10 to 90% humidity range. The two cells respond to these slow humidity oscillations with oscillations in impulse frequency which depend not only on instantaneous humidity but also on the rate with which humidity changes. The impulse frequency of each cell was plotted as a function of these two parameters and regression planes were fitted to the data points of single oscillation periods. The regression slopes, which estimate sensitivity, rose with the amplitude of humidity oscillations. During large-amplitude oscillations, moist and dry cell sensitivity for instantaneous humidity and its rate of change was high. During small-amplitude oscillations, their sensitivity for both parameters was low, less exactly reflecting humidity fluctuations. Nothing is known about the spatial and temporal humidity variations a honeybee may encounter when flying through natural environments. Microclimatic parameters (absolute humidity, temperature, wind speed) were measured from an automobile traveling through different landscapes of Lower Austria. Landscape type affected extremes and mean values of humidity. Differences between peaks and troughs of humidity fluctuations were generally smaller in open grassy fields or deciduous forests than in edge habitats or forest openings. Overall, fluctuation amplitudes were small. In this part of the stimulus range, hygroreceptor sensitivity is not optimal for encoding instantaneous humidity and the rate of humidity change. It seems that honeybee's hygroreceptors are specialized for detecting large-amplitude fluctuations that are relevant for a specific behavior, namely, maintaining a sufficiently stable state of water balance. The results suggest that optimal sensitivity of both hygroreceptors is shaped not only by humidity oscillation amplitudes but also

  17. Sensitivity of honeybee hygroreceptors to slow humidity changes and temporal humidity variation detected in high resolution by mobile measurements.

    PubMed

    Tichy, Harald; Kallina, Wolfgang

    2014-01-01

    The moist cell and the dry cell on the antenna of the male honeybee were exposed to humidities slowly rising and falling at rates between -1.5%/s and +1.5%/s and at varying amplitudes in the 10 to 90% humidity range. The two cells respond to these slow humidity oscillations with oscillations in impulse frequency which depend not only on instantaneous humidity but also on the rate with which humidity changes. The impulse frequency of each cell was plotted as a function of these two parameters and regression planes were fitted to the data points of single oscillation periods. The regression slopes, which estimate sensitivity, rose with the amplitude of humidity oscillations. During large-amplitude oscillations, moist and dry cell sensitivity for instantaneous humidity and its rate of change was high. During small-amplitude oscillations, their sensitivity for both parameters was low, less exactly reflecting humidity fluctuations. Nothing is known about the spatial and temporal humidity variations a honeybee may encounter when flying through natural environments. Microclimatic parameters (absolute humidity, temperature, wind speed) were measured from an automobile traveling through different landscapes of Lower Austria. Landscape type affected extremes and mean values of humidity. Differences between peaks and troughs of humidity fluctuations were generally smaller in open grassy fields or deciduous forests than in edge habitats or forest openings. Overall, fluctuation amplitudes were small. In this part of the stimulus range, hygroreceptor sensitivity is not optimal for encoding instantaneous humidity and the rate of humidity change. It seems that honeybee's hygroreceptors are specialized for detecting large-amplitude fluctuations that are relevant for a specific behavior, namely, maintaining a sufficiently stable state of water balance. The results suggest that optimal sensitivity of both hygroreceptors is shaped not only by humidity oscillation amplitudes but also

  18. Imaging of ancient Egyptian mummies' temporal bones with digital volume tomography.

    PubMed

    Dalchow, C V; Schmidt, C; Harbort, J; Knecht, R; Grzyska, U; Muenscher, A

    2012-10-01

    The radiographic imaging of ancient Egyptian mummies has always been of great interest. Computed tomography is the method of choice to demonstrate bony pathologies with high quality. As digital volume tomography (DVT) is an extension of panoramic tomography with a very high resolution, its qualities were evaluated by examination of temporal bones of Egyptian mummy skulls. Ten Egyptian mummy skulls from the Zoological Collection Marburg, estimated 1,700-5,000 years of age, from Abydos, Philae, Theben-West and Sakkarah, were examined by DVT (3D Accuitomo, Morita, Japan). Through a rotation 360° of the X-ray source around the region of interest, a cylinder of 3 × 4 cm was captured as a three-dimensional volume. The gained data were analyzed with the help of special software on a PC. The angles of the axial, coronal and sagittal sections were arbitrarily changed to represent single structures with high resolution of 0.125 mm to analyze specific anatomical structures. In all skulls, conditions of the temporal bone and its anatomical structures were evaluated and normal as well as pathological findings evaluated in detail. The analysis of special landmarks such as the ossicular chain, cochlea, external, and internal auditory canal, facial nerve canal, and semicircular canals showed an intact ossicular chain in six temporal bones, while only isolated and dislocated ossicles were found in eight temporal bones. Besides one dehiscence of the superior semicircular canal in one temporal bone which might have led to vertigo and deafness at lifetime, all other findings were normal. Fragments of foreign bodies additionally found in the labyrinth, external ear canal and intracranially were attributed to postmortem damage. Digital volume tomography extends the imaging possibilities of CT for paleoradiological evaluation of temporal bones. With its high resolution, geometric accuracy, reconstruction capabilities, rapidness, and comparably low costs, even small bony pathologies are

  19. Constructing a High-Resolution Temporal Record of Spreading-Rate Variations Along the Mid-Atlantic Ridge

    NASA Astrophysics Data System (ADS)

    Carchedi, C. J. W.; Dalton, C. A.; Herbert, T.

    2016-12-01

    Paleoclimate records provide an opportunity to investigate links between major changes in Earth's climate and long-term forcing mechanisms. While changes in atmospheric CO2 appear to drive trends in climate, global ocean cooling in the late Miocene remains an enigma: most CO2 proxies do not show a corresponding decline over this period. To improve constraints on the global carbon cycle over this time, we are constructing a new global synthesis of variations in ridge spreading rates with high temporal resolution over the past 20 Myr. We utilize newly available compilations of seafloor fabric and marine magnetic anomalies that are provided by the Global Seafloor Fabric and Magnetic Lineation Data Base Project (Matthews et al., 2011; Seton et al., 2014). Our initial focus is the northern Mid-Atlantic Ridge, where spreading is preserved on both ridge flanks, and dense data sets of magnetic anomalies are available. To obtain accurate and precise values of time, we use a new orbital timescale for magnetic reversal ages. Tectonic flow lines are generated from seafloor fabric, using continuous fracture zones extending from transform faults along the current ridge out to seafloor > 30 Myr. The cumulative distance each point on the flow line has traveled from the ridge is computed. Nearby magnetic anomalies are projected onto the flow line along lines normal to the flow line. Spreading rate as a function of seafloor age is then determined from age-distance relationships; both ridge flanks are treated separately to investigate spreading asymmetry. To improve the profiles' signal to noise ratios, we then stack the anomaly crossings onto composite east and west spreading profiles. Our preliminary analysis shows that spreading rates have decreased significantly from the mid-Miocene to the present, beginning around 15 Ma and experiencing a pronounced reduction during 8 to 5 Ma. This trend mirrors the decline observed in global sea surface temperatures, suggesting that tectonic

  20. Use of high resolution dual-energy x-ray absorptiometry-region free analysis (DXA-RFA) to detect local periprosthetic bone remodeling events.

    PubMed

    Wilkinson, J Mark; Morris, Richard M; Martin-Fernandez, Miguel A; Pozo, Jose M; Frangi, Alejandro F; Maheson, Marci; Yang, Lang

    2015-05-01

    Dual-energy x-ray absorptiometry (DXA) is the gold standard method for measuring periprosthetic bone remodeling, but relies on a region of interest (ROI) analysis approach. While this addresses issues of anatomic variability, it is insensitive to bone remodeling events at the sub-ROI level. We have validated a high-spatial resolution tool, termed DXA-region free analysis (DXA-RFA) that uses advanced image processing approaches to allow quantitation of bone mineral density (BMD) at the individual pixel (data-point) level. Here we compared the resolution of bone remodeling measurements made around a stemless femoral prosthesis in 18 subjects over 24 months using ROI-based analysis versus that made using DXA-RFA. Using the ROI approach the regional pattern of BMD change varied by region, with greatest loss in ROI5 (20%, p < 0.001), and largest gain in ROI4 (6%, p < 0.05). Analysis using DXA-RFA showed a focal zone of increased BMD localized to the prosthesis-bone interface (30-40%, p < 0.001) that was not resolved using conventional DXA analysis. The 20% bone loss observed in ROI5 with conventional DXA was resolved to a focal area adjacent to the cut surface of the infero-medial femoral neck (up to 40%, p < 0.0001). DXA-RFA enables high resolution analysis of DXA datasets without the limitations incurred using ROI-based approaches. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  1. [Modern imaging of the temporal bone].

    PubMed

    Kösling, S

    2017-06-01

    This article describes the current significance of computed tomography (CT), magnetic resonance imaging (MRI), cone beam CT, digital subtraction angiography (DSA), and special X‑rays in the diagnostics of temporal bone diseases. The latter is obsolete for diagnostic intentions. Possibilities and limitations in terms of detection and/or depiction of the extent of inflammatory, traumatic, tumorous, and postoperative pathologies are discussed. A concrete question and conveyance of clinical findings influence the choice of the method to be applied in the individual case. Malformations of the middle ear can only be detected noninvasively by CT or cone beam CT. These are also the methods that may support the diagnosis of otosclerosis in clinically unclear cases. MRI is the method of choice for pathologies of the inner ear and internal auditory canal, including inner ear malformations. At present, only in few institutions is a successful visualization of endolymphatic hydrops in Menière's disease realized.

  2. Bone geometry, density, and microarchitecture in the distal radius and tibia in adults with osteogenesis imperfecta type I assessed by high-resolution pQCT.

    PubMed

    Folkestad, Lars; Hald, Jannie Dahl; Hansen, Stinus; Gram, Jeppe; Langdahl, Bente; Abrahamsen, Bo; Brixen, Kim

    2012-06-01

    Osteogenesis imperfecta (OI) is a hereditary disorder characterized by decreased biosynthesis or impaired morphology of type I collagen that leads to decreased bone mass and increased bone fragility. We hypothesized that patients with OI have altered bone microstructure and bone geometry. In this cross-sectional study we compared patients with type I OI to age- and gender-matched healthy controls. A total of 39 (13 men and 26 women) patients with OI, aged 53 (range, 21-77) years, and 39 controls, aged 53 (range, 21-77) years, were included in the study. Twenty-seven of the patients had been treated with bisphosphonates. High-resolution peripheral quantitative computed tomography (HR-pQCT) at the distal radius and distal tibia and dual-energy X-ray absorptiometry of total hip, femoral neck, trochanteric region, and the lumbar spine (L1-L4) were performed. The patients were shorter than the controls (159 ± 10 cm versus 170 ± 9 cm, p < 0.001), but had similar body weight. In OI, areal bone mineral density (aBMD) was 8% lower at the hip (p < 0.05) and 13% lower at the spine (p < 0.001) compared with controls. The trabecular volumetric bone mineral density (vBMD) was 28% lower in radius (p < 0.001) and 38% lower in tibia (p < 0.001) in OI compared with controls. At radius, total bone area was 5% lower in OI than in controls (p < 0.05). In the tibia, cortical bone area was 18% lower in OI (p < 0.001). In both radius and tibia the number of trabeculae was lower in patients compared to the controls (35% and 38%, respectively, p < 0.001 at both sites). Furthermore, trabecular spacing was 55% higher in OI in both tibia and radius (p < 0.001 at both sites) when compared with controls. We conclude that patients with type I OI have lower aBMD, vBMD, bone area, and trabecular number when compared with healthy age- and gender-matched controls.

  3. Comparison of pixel and sub-pixel based techniques to separate Pteronia incana invaded areas using multi-temporal high resolution imagery

    NASA Astrophysics Data System (ADS)

    Odindi, John; Kakembo, Vincent

    2009-08-01

    Remote Sensing using high resolution imagery (HRI) is fast becoming an important tool in detailed land-cover mapping and analysis of plant species invasion. In this study, we sought to test the separability of Pteronia incana invader species by pixel content aggregation and pixel content de-convolution using multi-temporal infrared HRI. An invaded area in Eastern Cape, South Africa was flown in 2001, 2004 and 2006 and HRI of 1x1m resolution captured using a DCS 420 colour infrared camera. The images were separated into bands, geo-rectified and radiometrically corrected using Idrisi Kilimanjaro GIS. Value files were extracted from the bands in order to compare spectral values for P. incana, green vegetation and bare surfaces using the pixel based Perpendicular Vegetation Index (PVI), while Constrained Linear Spectral Unmixing (CLSU) surface endmembers were used to generate sub-pixel land surface image fractions. Spectroscopy was used to validate spectral trends identified from HRI. The PVI successfully separated the multi-temporal imagery surfaces and was consistent with the unmixed surface image fractions from CLSU. Separability between the respective surfaces was also achieved using reflectance measurements.

  4. Effects of temporal dimensional instability on the Advanced X-ray Astrophysics Facility (AXAF-I) high-resolution mirror assembly (HRMA)

    NASA Astrophysics Data System (ADS)

    Cohen, Lester M.

    1995-06-01

    The NASA Advanced X-ray Astrophysics Facility-Imaging (AXAF-I), one of NASA's Great Observatories, will be launched in 1998. The AXAF-I High Resolution Mirror Assembly (HRMA) will provide sub-arc second imaging resolution over the expected mission life of five years. During assembly and operational life of the telescope, small dimensional changes of the structural support system can degrade the telescopes resolving power by introducing unwanted forces. The forces that are introduced depend, in part, on the long term temporal dimensional stability of the materials that are used in the telescope. A year-long stability study carried out at the university of Arizona Dimensional Stability Laboratory recently concluded. Cyanate ester-based composites, 7050-T7451 aluminum, LR-35 invar, 6Al-4V titanium, 6061-T6 aluminum and Zerodur were studied. The Zerodur material was found to be stable to better than 0.03 ppm/yr. The titanium was found to be stable to better than 0.5 ppm/yr. The 7050- T7451 aluminum and cyanate ester-based composites were found relatively unstable but their instability improved significantly with time. Monte-Carlo and deterministic techniques were used to predict the effects of the instability on the telescopes' performance. Temporal instability effects were within the systems top level requirements.

  5. Reconstructing Large-Scale Brain Resting-State Networks from High-Resolution EEG: Spatial and Temporal Comparisons with fMRI.

    PubMed

    Yuan, Han; Ding, Lei; Zhu, Min; Zotev, Vadim; Phillips, Raquel; Bodurka, Jerzy

    2016-03-01

    Functional magnetic resonance imaging (fMRI) studies utilizing measures of hemodynamic signal, such as the blood oxygenation level-dependent (BOLD) signal, have discovered that resting-state brain activities are organized into multiple large-scale functional networks, coined as resting-state networks (RSNs). However, an important limitation of the available fMRI studies is that hemodynamic signals only provide an indirect measure of the neuronal activity. In contrast, electroencephalography (EEG) directly measures electrophysiological activity of the brain. However, little is known about the brain-wide organization of such spontaneous neuronal population signals at the resting state. It is not entirely clear if or how the network structure built upon slowly fluctuating hemodynamic signals is represented in terms of fast, dynamic, and spontaneous neuronal activity. In this study, we investigated the electrophysiological representation of RSNs from simultaneously acquired EEG and fMRI data in the resting human brain. We developed a data-driven analysis approach that reconstructed multiple large-scale electrophysiological networks from high-resolution EEG data alone. The networks derived from EEG were then compared with RSNs independently derived from simultaneously acquired fMRI in their spatial structures as well as temporal dynamics. Results reveal spatially and temporally specific electrophysiological correlates for the fMRI-RSNs. Findings suggest that the spontaneous activity of various large-scale cortical networks is reflected in macroscopic EEG potentials.

  6. CT Findings in Temporal Bone Osteoradionecrosis

    PubMed Central

    Ahmed, Salmaan; Gupta, Nakul; Hamilton, Jackson D.; Garden, Adam S.; Gidley, Paul W.; Ginsberg, Lawrence E.

    2014-01-01

    Purpose The goal of this study is to describe CT findings in patients with clinically proven temporal bone osteoradionecrosis (TB-ORN). Methods and materials CT scans of twenty patients were retrospectively evaluated for bony and soft tissue abnormalities. Clinical severity was graded based on level of therapy administered: mild (observation), moderate (antibiotics/hyperbaric oxygen), or severe (surgery). Results Radiation dose to the primary tumor ranged from 30 to 75.6 Gy. Time to onset of ORN from completion of radiation therapy was 2 to 22 years (median=7yrs). Clinical findings: Exposed bone=20/20, otorrhea=17/20, hearing loss=11/20, otalgia=10/20, facial nerve paralysis=2/20, gait imbalance=2/20. CT findings: EAC erosions=18/20, mastoid effusion=18/20, mastoid bony coalescence=5/20, enhancing soft tissue=6/20, soft tissue gas=6/20, temporomandibular joint/condylar erosion=3/20. 3 patients developed an abscess. Conclusion Mastoid effusion and EAC erosions are commonly seen with TB-ORN. Clinically moderate or severe cases of TB-ORN are more likely to demonstrate enhancing soft tissue (p=0.002), soft tissue gas (p=0.002), and temporomandibular joint involvement (p=0.07). PMID:24834883

  7. Chemodectomas arising in temporal bone structures

    SciTech Connect

    Dickens, W.J.; Million, R.R.; Cassisi, N.J.; Singleton, G.T.

    1982-02-01

    Eighteen patients with chemodectomas arising in temporal bone structures were evaluated and treated at the University of Florida. Seventeen patients have each been followed a minimum of 3 years. Patients were retrospectively staged as having ''local'' or ''advanced'' disease, depending on the presence or absence of bone destruction and/or cranial nerve involvement. Fourteen of the patients received radiation therapy as all or part of their therapy; 6 patients were treated with radiation therapy alone, 3 patients were irradiated immediately postoperatively for residual disease, and 5 patients had radiation therapy for recurrence after operation. They were treated with cobalt-60 radiation with doses ranging from 3760 to 5640 rad. All irradiated patients demonstrated evidence of tumor regression, and none have had tumor recurrence with followup of 3-12 years. Of the 8 patients with cranial nerve paralysis prior to therapy, 5 had return of function of 1 or more cranial nerves. One of 6 patients treated initially with radiation therapy had a complication, while 6 of 8 patients irradiated postoperatively had complications. None of the complications were fatal. Three patients treated by operation for early disease limited to the hypotympanum had the disease controlled for 11-12 years. Guidelines for the selection of initial therapy are discussed.

  8. Correlation among external auditory canal anomaly, temporal bone malformation, and hearing levels in patients with microtia.

    PubMed

    Chen, Kun; Liu, Liu; Shi, Runjie; Wang, Peihua; Chen, Dong; Xiao, Hua

    2017-06-01

    We conducted a retrospective study to evaluate the relationship between external auditory canal (EAC) anomaly, temporal bone abnormality, and hearing levels using objective scoring systems in Chinese patients with microtia. The study population consisted of 106 ears of 94 Chinese patients (67 male and 27 female) aged 5 to 45 years (mean: 12.6) with microtia. The EAC abnormalities were classified into 4 types according to Schuknecht's criteria: type A, type B, type C, and type D. Developmental anomalies of the temporal bone were evaluated by Jahrsdoerfer computed tomography (CT) scoring system using high-resolution CT scans of the temporal bone. Temporal bone malformation parameters were divided into 4 subgroups: ossicular chain development, windows connected to the cochlea, aeration development of the middle ear, and facial nerve aberration. Hearing levels (air conduction and bone conduction) were examined. Outcomes parameters included correlation coefficients (r) and a number of other variables. The total points (10 points) and subtotal points related to ossicles (4 points), windows (2 points), aeration (2 points), and facial nerve (1 point) correlated inversely with the EAC abnormalities. The hearing levels (air conduction, r = 0.396, p <0.01; bone conduction, r = 0.21, p = 0.03) correlated significantly with the EAC abnormalities of Schuknecht's classification. We conclude that the better developed the external auditory canal, the better developed the temporal bone and the better developed the external auditory canal, the better hearing level. The hearing level also can serve as an indicator to determine whether a patient will be suitable for reconstructive surgery.

  9. Towards widespread exploitation of high resolution multi-temporal interferometry for monitoring landslide activity: a case-study of Southern Gansu, China

    NASA Astrophysics Data System (ADS)

    Wasowski, Janusz; Bovenga, Fabio; Dijkstra, Tom; Meng, Xingmin; Nutricato, Raffaele; Chiaradia, Maria Teresa

    2014-05-01

    Although Multi-Temporal Interferometry (MTI) techniques are considered to have already reached the operational level, it is apparent that, in both research and practice, we are only just beginning to benefit from the high resolution imagery that is currently acquired by the new generation of radar satellites. MTI techniques are not applicable in any environment, but, nonetheless, we foresee a strong possibility that in the future these techniques will see widespread exploitation in support of slope hazard assessments. MTI applications will become increasingly important in cases where little or no conventional monitoring is feasible (e.g. remote locations and limited funds). The tremendous potential of MTI is illustrated using selected examples of applications ranging from local to catchment scales. A particular focus is on the use of MTI for the investigation of slope instability in the remote high mountain region of Zhouqu, Southern Gansu, known to be affected by large magnitude (M7-8) earthquakes and catastrophic mass movements. The MTI processing of high resolution (~3 m) COSMO/SkyMed (CSK) satellite images produced spatially dense information (more than 1000 radar targets/km2) on ground surface displacements. A substantial portion of the radar targets showed significant displacements (from few to over 100 mm/yr), denoting widespread slope instability. In particular, the MTI results provided valuable information on the activity of some very large, apparently slow moving landslides that represent a persistent hazard to the local population and infrastructure, particularly as these landslides are known to undergo periods of increased activity resulting in river damming and disastrous flooding. Given the general lack of field monitoring data on slope instability in Southern Gansu, the MTI-derived displacements offer a unique form of remote displacement monitoring that provides valuable information to experts tasked with formulating strategies for hazard management

  10. Multi-platform validation of a high-resolution model in the Western Mediterranean Sea: insight into spatial-temporal variability

    NASA Astrophysics Data System (ADS)

    Aguiar, Eva; Mourre, Baptiste; Heslop, Emma; Juza, Mélanie; Escudier, Romain; Tintoré, Joaquín

    2017-04-01

    This study focuses on the validation of the high resolution Western Mediterranean Operational model (WMOP) developed at SOCIB, the Balearic Islands Coastal Observing and Forecasting System. The Mediterranean Sea is often seen as a small scale ocean laboratory where energetic eddies, fronts and circulation features have important ecological consequences. The Medclic project is a program between "La Caixa" Foundation and SOCIB which aims at characterizing and forecasting the "oceanic weather" in the Western Mediterranean Sea, specifically investigating the interactions between the general circulation and mesoscale processes. We use a WMOP 2009-2015 free run hindcast simulation and available observational datasets (altimetry, moorings and gliders) to both assess the numerical simulation and investigate the ocean variability. WMOP has a 2-km spatial resolution and uses CMEMS Mediterranean products as initial and boundary conditions, with surface forcing from the high-resolution Spanish Meteorological Agency model HIRLAM. Different aspects of the spatial and temporal variability in the model are validated from local to regional and basin scales: (1) the principal axis of variability of the surface circulation using altimetry and moorings along the Iberian coast, (2) the inter-annual changes of the surface flows incorporating also glider data, (3) the propagation of mesoscale eddies formed in the Algerian sub-basin using altimetry, and (4) the statistical properties of eddies (number, rotation, size) applying an eddy tracker detection method in the Western Mediterranean Sea. With these key points evaluated in the model, EOF analysis of sea surface height maps are used to investigate spatial patterns of variability associated with eddies, gyres and the basis-scale circulation and so gain insight into the interconnections between sub-basins, as well as the interactions between physical processes at different scales.

  11. Radiation injury to the temporal bone

    SciTech Connect

    Guida, R.A.; Finn, D.G.; Buchalter, I.H.; Brookler, K.H.; Kimmelman, C.P. )

    1990-01-01

    Osteoradionecrosis of the temporal bone is an unusual sequela of radiation therapy to the head and neck. Symptoms occur many years after the radiation is administered, and progression of the disease is insidious. Hearing loss (sensorineural, conductive, or mixed), otalgia, otorrhea, and even gross tissue extrusion herald this condition. Later, intracranial complications such as meningitis, temporal lobe or cerebellar abscess, and cranial neuropathies may occur. Reported here are five cases of this rare malady representing varying degrees of the disease process. They include a case of radiation-induced necrosis of the tympanic ring with persistent squamous debris in the external auditory canal and middle ear. Another case demonstrates the progression of radiation otitis media to mastoiditis with bony sequestration. Further progression of the disease process is seen in a third case that evolved into multiple cranial neuropathies from skull base destruction. Treatment includes systemic antibiotics, local wound care, and debridement in cases of localized tissue involvement. More extensive debridement with removal of sequestrations, abscess drainage, reconstruction with vascularized tissue from regional flaps, and mastoid obliteration may be warranted for severe cases. Hyperbaric oxygen therapy has provided limited benefit.

  12. Visual grading of motion induced image degradation in high resolution peripheral computed tomography: impact of image quality on measures of bone density and micro-architecture.

    PubMed

    Pialat, J B; Burghardt, A J; Sode, M; Link, T M; Majumdar, S

    2012-01-01

    Motion artifacts are a common finding during high-resolution peripheral quantitative computed tomography (HR-pQCT) image acquisitions. To date it is not clear (i) when to repeat an acquisition, (ii) when to exclude a motion-degraded dataset post hoc, and (iii) how motion induced artifacts impact measures of trabecular and cortical parameters. In this study we present inter- and intra-observer reproducibility of a qualitative image quality grading score and report the prevalence of repeat acquisitions in our population. Finally the errors in bone density and micro-architectural parameters estimated from repeat acquisitions with and without motion degradation are presented. The relationship between these errors and the image quality grade is evaluated for each parameter. Repeat acquisitions performed due to operator-observed motion in the reconstructed image occurred for 22.7% of the exams (29.7% radius, 15.7% tibia). Of this subset, 88 exams with repeat acquisitions had at least one acquisition graded 1 (best quality). In this subset, the percent differences in bone density and micro-architecture measures tended to increase as the relative image quality decreased. Micro-architectural parameters were more sensitive to motion compared to geometric and densitometric parameters. These results provide estimates of the error in bone quality measures due to motion artifacts and provide an initial framework for developing standardized quality control criteria for cross-sectional and longitudinal HR-pQCT studies.

  13. Cancer of the external auditory canal and temporal bone.

    PubMed

    Kuhel, W I; Hume, C R; Selesnick, S H

    1996-10-01

    Malignant tumors involving the structures of the temporal bone represent formidable diagnostic and therapeutic challenges for clinicians involved in the treatment of otologic disease. This article offers a perspective on the current understanding of the biology of malignancies involving the external auditory canal, middle ear space, and temporal bone, and reviews the often confusing and contradictory literature on this topic.

  14. Distal radius plate of CFR-PEEK has minimal effect compared to titanium plates on bone parameters in high-resolution peripheral quantitative computed tomography: a pilot study.

    PubMed

    de Jong, Joost J A; Lataster, Arno; van Rietbergen, Bert; Arts, Jacobus J; Geusens, Piet P; van den Bergh, Joop P W; Willems, Paul C

    2017-02-27

    Carbon-fiber-reinforced poly-ether-ether-ketone (CFR-PEEK) has superior radiolucency compared to other orthopedic implant materials, e.g. titanium or stainless steel, thus allowing metal-artifact-free postoperative monitoring by computed tomography (CT). Recently, high-resolution peripheral quantitative CT (HRpQCT) proved to be a promising technique to monitor the recovery of volumetric bone mineral density (vBMD), micro-architecture and biomechanical parameters in stable conservatively treated distal radius fractures. When using HRpQCT to monitor unstable distal radius fractures that require volar distal radius plating for fixation, radiolucent CFR-PEEK plates may be a better alternative to currently used titanium plates to allow for reliable assessment. In this pilot study, we assessed the effect of a volar distal radius plate made from CFR-PEEK on bone parameters obtained from HRpQCT in comparison to two titanium plates. Plates were instrumented in separate cadaveric human fore-arms (n = 3). After instrumentation and after removal of the plates duplicate HRpQCT scans were made of the region covered by the plate. HRpQCT images were visually checked for artifacts. vBMD, micro-architectural and biomechanical parameters were calculated, and compared between the uninstrumented and instrumented radii. No visible image artifacts were observed in the CFR-PEEK plate instrumented radius, and errors in bone parameters ranged from -3.2 to 2.6%. In the radii instrumented with the titanium plates, severe image artifacts were observed and errors in bone parameters ranged between -30.2 and 67.0%. We recommend using CFR-PEEK plates in longitudinal in vivo studies that monitor the healing process of unstable distal radius fractures treated operatively by plating or bone graft ingrowth.

  15. Registration-based autofocusing technique for automatic correction of motion artifacts in time-series studies of high-resolution bone MRI.

    PubMed

    Zhang, Ning; Magland, Jeremy F; Song, Hee Kwon; Wehrli, Felix W

    2015-04-01

    To develop a registration-based autofocusing (RAF) motion correction technique for high-resolution trabecular bone (TB) imaging and to evaluate its performance on in vivo MR data. The technique combines serial registration with a previously developed motion correction technique - autofocusing - for automatic correction of subject movement degradation of MR images acquired in longitudinal studies. The method was tested on in vivo images of the distal radius to measure improvements in serial reproducibility of parameters in 12 women (ages 50-75 years), and to compare with the navigator echo-based correction and autofocusing. Furthermore, the technique's ability to optimize the sensitivity to detect simulated bone loss was ascertained. The new technique yielded superior reproducibility of image-derived structural and mechanical parameters. Average coefficient of variation across all parameters improved by 12.5%, 27.0%, 33.5%, and 37.0%, respectively, following correction by navigator echoes, autofocusing, and the RAF technique (without and with correction for rotational motion); average intra-class correlation coefficient increased by 1.2%, 2.2%, 2.8%, and 3.2%, respectively. Furthermore, simulated bone loss (5%) was well recovered independent of the choice of reference image (4.71% or 4.86% with respect to using either the original or the image subjected to bone loss) in the time series. The data suggest that our technique simultaneously corrects for intra-scan motion corruption while improving inter-scan registration. Furthermore, the technique is not biased by small changes in bone architecture between time-points. © 2014 Wiley Periodicals, Inc.

  16. Temporal fossa bone grafts: a new technique in craniofacial surgery.

    PubMed

    Spear, S L; Wiegering, C E

    1987-04-01

    The calvarium has become an increasingly popular bone-graft donor site. Previously described harvesting techniques are often difficult to perform and may produce unsatisfactory bone fragments. However, full-thickness bone grafts taken from the region of the temporal fossa, beneath the temporaiis muscle, have proven to be of high quality and technically easy to obtain. In our experience with eight patients, temporal fossa bone grafts were used primarily around the orbit, including reconstruction of the orbital floor, frontal bone, and zygoma. The procedure begins with a hemicoronal or bicoronal incision; the temporalis muscle is reflected, and an underlying bone plate up to 4 X 6 cm is removed. The resulting bone graft is consistently 3 to 4 mm in thickness. The cranial defect is packed with bone debris, and the muscle is replaced. This technique has proven to be safe, technically simple, consistently productive of high-quality bone grafts, and within discernible donor-site deformity.

  17. Three-dimensional reconstruction of the temporal bone.

    PubMed

    Green, J D; Marion, M S; Erickson, B J; Robb, R A; Hinojosa, R

    1990-01-01

    Study of the complex anatomy and pathology of the temporal bone has traditionally used microscopy which permits analysis in only two dimensions. Recent advances in bioimaging technology have permitted visualization and reconstruction of computed tomography images in three dimensions. We have developed a technique that applies this technology in the imaging and reconstruction of human temporal bones. Data taken from serial histologic sections of the temporal bone are entered into a computer. The sections are edited and, through the use of specially developed software, a realistic three-dimensional reconstruction is produced. The reconstructed image can be rotated along any of three axes, and structures within the temporal bone can be isolated for more detailed analysis. Applications for the study of pathologic conditions of the temporal bone will be discussed.

  18. Forest fuel treatment detection using multi-temporal airborne Lidar data and high resolution aerial imagery ---- A case study at Sierra Nevada, California

    NASA Astrophysics Data System (ADS)

    Su, Y.; Guo, Q.; Collins, B.; Fry, D.; Kelly, M.

    2014-12-01

    Forest fuel treatments (FFT) are often employed in Sierra Nevada forest (located in California, US) to enhance forest health, regulate stand density, and reduce wildfire risk. However, there have been concerns that FFTs may have negative impacts on certain protected wildlife species. Due to the constraints and protection of resources (e.g., perennial streams, cultural resources, wildlife habitat, etc.), the actual FFT extents are usually different from planned extents. Identifying the actual extent of treated areas is of primary importance to understand the environmental influence of FFTs. Light detection and ranging (Lidar) is a powerful remote sensing technique that can provide accurate forest structure measurements, which provides great potential to monitor forest changes. This study used canopy height model (CHM) and canopy cover (CC) products derived from multi-temporal airborne Lidar data to detect FFTs by an approach combining a pixel-wise thresholding method and a object-of-interest segmentation method. We also investigated forest change following the implementation of landscape-scale FFT projects through the use of normalized difference vegetation index (NDVI) and standardized principle component analysis (PCA) from multi-temporal high resolution aerial imagery. The same FFT detection routine was applied on the Lidar data and aerial imagery for the purpose of comparing the capability of Lidar data and aerial imagery on FFT detection. Our results demonstrated that the FFT detection using Lidar derived CC products produced both the highest total accuracy and kappa coefficient, and was more robust at identifying areas with light FFTs. The accuracy using Lidar derived CHM products was significantly lower than that of the result using Lidar derived CC, but was still slightly higher than using aerial imagery. FFT detection results using NDVI and standardized PCA using multi-temporal aerial imagery produced almost identical total accuracy and kappa coefficient

  19. Temporal Variability in Vertical Groundwater Fluxes and the Effect of Solar Radiation on Streambed Temperatures Based on Vertical High Resolution Distributed Temperature Sensing

    NASA Astrophysics Data System (ADS)

    Sebok, E.; Karan, S.; Engesgaard, P. K.; Duque, C.

    2013-12-01

    Due to its large spatial and temporal variability, groundwater discharge to streams is difficult to quantify. Methods using vertical streambed temperature profiles to estimate vertical fluxes are often of coarse vertical spatial resolution and neglect to account for the natural heterogeneity in thermal conductivity of streambed sediments. Here we report on a field investigation in a stream, where air, stream water and streambed sediment temperatures were measured by Distributed Temperature Sensing (DTS) with high spatial resolution to; (i) detect spatial and temporal variability in groundwater discharge based on vertical streambed temperature profiles, (ii) study the thermal regime of streambed sediments exposed to different solar radiation influence, (iii) describe the effect of solar radiation on the measured streambed temperatures. The study was carried out at a field site located along Holtum stream, in Western Denmark. The 3 m wide stream has a sandy streambed with a cobbled armour layer, a mean discharge of 200 l/s and a mean depth of 0.3 m. Streambed temperatures were measured with a high-resolution DTS system (HR-DTS). By helically wrapping the fiber optic cable around two PVC pipes of 0.05 m and 0.075 m outer diameter over 1.5 m length, temperature measurements were recorded with 5.7 mm and 3.8 mm vertical spacing, respectively. The HR-DTS systems were installed 0.7 m deep in the streambed sediments, crossing both the sediment-water and the water-air interface, thus yielding high resolution water and air temperature data as well. One of the HR-DTS systems was installed in the open stream channel with only topographical shading, while the other HR-DTS system was placed 7 m upstream, under the canopy of a tree, thus representing the shaded conditions with reduced influence of solar radiation. Temperature measurements were taken with 30 min intervals between 16 April and 25 June 2013. The thermal conductivity of streambed sediments was calibrated in a 1D flow

  20. Lean mass and fat mass have differing associations with bone microarchitecture assessed by high resolution peripheral quantitative computed tomography in men and women from the Hertfordshire Cohort Study.

    PubMed

    Edwards, Mark H; Ward, Kate A; Ntani, Georgia; Parsons, Camille; Thompson, Jennifer; Sayer, Avan A; Dennison, Elaine M; Cooper, Cyrus

    2015-12-01

    Understanding the effects of muscle and fat on bone is increasingly important in the optimisation of bone health. We explored relationships between bone microarchitecture and body composition in older men and women from the Hertfordshire Cohort Study. 175 men and 167 women aged 72-81 years were studied. High resolution peripheral quantitative computed tomography (HRpQCT) images (voxel size 82 μm) were acquired from the non-dominant distal radius and tibia with a Scanco XtremeCT scanner. Standard morphological analysis was performed for assessment of macrostructure, densitometry, cortical porosity and trabecular microarchitecture. Body composition was assessed using dual energy X-ray absorptiometry (DXA) (Lunar Prodigy Advanced). Lean mass index (LMI) was calculated as lean mass divided by height squared and fat mass index (FMI) as fat mass divided by height squared. The mean (standard deviation) age in men and women was 76 (3) years. In univariate analyses, tibial cortical area (p<0.01), cortical thickness (p<0.05) and trabecular number (p<0.01) were positively associated with LMI and FMI in both men and women. After mutual adjustment, relationships between cortical area and thickness were only maintained with LMI [tibial cortical area, β (95% confidence interval (CI)): men 6.99 (3.97,10.01), women 3.59 (1.81,5.38)] whereas trabecular number and density were associated with FMI. Interactions by sex were found, including for the relationships of LMI with cortical area and FMI with trabecular area in both the radius and tibia (p<0.05). In conclusion, LMI and FMI appeared to show independent relationships with bone microarchitecture. Further studies are required to confirm the direction of causality and explore the mechanisms underlying these tissue-specific associations.

  1. Cluster Analysis of Bone Microarchitecture from High Resolution Peripheral Quantitative Computed Tomography Demonstrates two Separate Phenotypes Associated with High Fracture Risk in Men and Women

    PubMed Central

    Edwards, MH; Robinson, DE; Ward, KA; Javaid, MK; Walker-Bone, K; Cooper, C; Dennison, EM

    2016-01-01

    Osteoporosis is a major healthcare problem which is conventionally assessed by dual energy x-ray absorptiometry (DXA). New technologies such as high resolution peripheral quantitative computed tomography (HRpQCT) also predict fracture risk. HRpQCT measures a number of bone characteristics that may inform specific patterns of bone deficits. We used cluster analysis to define different bone phenotypes and their relationships to fracture prevalence and areal bone mineral density (BMD). 177 men and 159 women, in whom fracture history was determined by self-report and vertebral fracture assessment, underwent HRpQCT of the distal radius and femoral neck DXA. Five clusters were derived with two clusters associated with elevated fracture risk. “Cluster 1” contained 26 women (50.0% fractured) and 30 men (50.0% fractured) with a lower mean cortical thickness and cortical volumetric BMD, and in men only, a mean total and trabecular area more than the sex-specific cohort mean. “Cluster 2” contained 20 women (50.0% fractured) and 14 men (35.7% fractured) with a lower mean trabecular density and trabecular number than the sex-specific cohort mean. Logistic regression showed fracture rates in these clusters to be significantly higher than the lowest fracture risk cluster (5) (p<0.05). Mean femoral neck areal BMD was significantly lower than cluster 5 in women in cluster 1 and 2 (p<0.001 for both), and in men, in cluster 2 (p<0.001) but not 1 (p=0.220). In conclusion, this study demonstrates two distinct high risk clusters in both men and women which may differ in etiology and response to treatment. As cluster 1 in men does not have low areal BMD, these men may not be identified as high risk by conventional DXA alone. PMID:27130873

  2. Cluster analysis of bone microarchitecture from high resolution peripheral quantitative computed tomography demonstrates two separate phenotypes associated with high fracture risk in men and women.

    PubMed

    Edwards, M H; Robinson, D E; Ward, K A; Javaid, M K; Walker-Bone, K; Cooper, C; Dennison, E M

    2016-07-01

    Osteoporosis is a major healthcare problem which is conventionally assessed by dual energy X-ray absorptiometry (DXA). New technologies such as high resolution peripheral quantitative computed tomography (HRpQCT) also predict fracture risk. HRpQCT measures a number of bone characteristics that may inform specific patterns of bone deficits. We used cluster analysis to define different bone phenotypes and their relationships to fracture prevalence and areal bone mineral density (BMD). 177 men and 159 women, in whom fracture history was determined by self-report and vertebral fracture assessment, underwent HRpQCT of the distal radius and femoral neck DXA. Five clusters were derived with two clusters associated with elevated fracture risk. "Cluster 1" contained 26 women (50.0% fractured) and 30 men (50.0% fractured) with a lower mean cortical thickness and cortical volumetric BMD, and in men only, a mean total and trabecular area more than the sex-specific cohort mean. "Cluster 2" contained 20 women (50.0% fractured) and 14 men (35.7% fractured) with a lower mean trabecular density and trabecular number than the sex-specific cohort mean. Logistic regression showed fracture rates in these clusters to be significantly higher than the lowest fracture risk cluster [5] (p<0.05). Mean femoral neck areal BMD was significantly lower than cluster 5 in women in cluster 1 and 2 (p<0.001 for both), and in men, in cluster 2 (p<0.001) but not 1 (p=0.220). In conclusion, this study demonstrates two distinct high risk clusters in both men and women which may differ in etiology and response to treatment. As cluster 1 in men does not have low areal BMD, these men may not be identified as high risk by conventional DXA alone.

  3. 3D Fast Spin Echo With Out-of-Slab Cancellation: A Technique for High-Resolution Structural Imaging of Trabecular Bone at 7 Tesla

    PubMed Central

    Magland, Jeremy F.; Rajapakse, Chamith S.; Wright, Alexander C.; Acciavatti, Raymond; Wehrli, Felix W.

    2016-01-01

    Spin-echo-based pulse sequences are desirable for the application of high-resolution imaging of trabecular bone but tend to involve high-power deposition. Increased availability of ultrahigh field scanners has opened new possibilities for imaging with increased signal-to-noise ratio (SNR) efficiency, but many pulse sequences that are standard at 1.5 and 3 T exceed specific absorption rate limits at 7 T. A modified, reduced specific absorption rate, three-dimensional, fast spin-echo pulse sequence optimized specifically for in vivo trabecular bone imaging at 7 T is introduced. The sequence involves a slab-selective excitation pulse, low-power nonselective refocusing pulses, and phase cycling to cancel undesired out-of-slab signal. In vivo images of the distal tibia were acquired using the technique at 1.5, 3, and 7 T field strengths, and SNR was found to increase at least linearly using receive coils of identical geometry. Signal dependence on the choice of refocusing flip angles in the echo train was analyzed experimentally and theoretically by combining the signal from hundreds of coherence pathways, and it is shown that a significant specific absorption rate reduction can be achieved with negligible SNR loss. PMID:20187181

  4. MR neurographic orthopantomogram: Ultrashort echo-time imaging of mandibular bone and teeth complemented with high-resolution morphological and functional MR neurography.

    PubMed

    Manoliu, Andrei; Ho, Michael; Nanz, Daniel; Dappa, Evelyn; Boss, Andreas; Grodzki, David M; Liu, Wei; Chhabra, Avneesh; Andreisek, Gustav; Kuhn, Felix P

    2016-08-01

    Panoramical radiographs or cone-beam computed tomography (CT) are the standard-of-care in dental imaging to assess teeth, mandible, and mandibular canal pathologies, but do not allow assessment of the inferior alveolar nerve itself nor of its branches. We propose a new technique for "MR neurographic orthopantomograms" exploiting ultrashort echo-time (UTE) imaging of bone and teeth complemented with high-resolution morphological and functional MR neurography. The Institutional Review Board approved the study in 10 healthy volunteers. Imaging of the subjects mandibles at 3.0T (Magnetom Skyra, Siemens-Healthcare) using a 64-channel head coil with isotropic spatial resolution for subsequent multiplanar reformatting, was performed. Bone images were acquired using a 3D PETRA sequence (TE, 0.07 msec). Morphological nerve imaging was performed using a dedicated 3D PSIF and 3D SPACE STIR sequence. Functional MR neurography was accomplished using a new accelerated diffusion-tensor-imaging (DTI) prototype sequence (2D SMS-accelerated RESOLVE). Qualitative and quantitative image analysis was performed and descriptive statistics are provided. Image acquisition and subsequent postprocessing into the MR neurographic orthopantomogram by overlay of morphological and functional images were feasible in all 10 volunteers without artifacts. All mandibular bones and mandibular nerves were assessable and considered normal. Fiber tractography with quantitative evaluation of physiological diffusion properties of mandibular nerves yielded the following mean ± SD values: fractional anisotropy, 0.43 ± 0.07; mean diffusivity (mm(2) /s), 0.0014 ± 0.0002; axial diffusivity, 0.0020 ± 0.0002, and radial diffusivity, 0.0011 ± 0.0001. The proposed technique of MR neurographic orthopantomogram exploiting UTE imaging complemented with high-resolution morphological and functional MR neurography was feasible and allowed comprehensive assessment of osseous texture and neural

  5. Temporal bone dissection practice using a chicken egg.

    PubMed

    Meléndez García, José Manuel; Araujo Da Costa, Ana Sofía; Rivera Schmitz, Teresa; Chiesa Estomba, Carlos Miguel; Hamdan Zavarce, Miriam Ileana

    2014-07-01

    Temporal bone drilling practice constitutes an essential stage in training for the surgical approach to this complex anatomic structure. To facilitate adaptation and surgical skills in otologic surgery, we recall the easy cost-effective practice of drilling a chicken egg. The resident in training must master the use of the surgical microscope, the burr, and fine drilling instruments used in dissection. Animal models, plastic temporal bones, prototyped temporal bones, and virtual reality temporal bones have all been used. This article describes a method of training residents' otologic skills by drilling a chicken egg. We used basic support materials found in a typical temporal bone dissection laboratory, with a surgical microscope, a desk, and a drilling system. Practice includes drilling and dissection of the eggshell, preserving the natural eggshell membrane. Learning temporal bone drilling on an egg, using basic materials, allows the surgeon to simulate surgery on a physical model using the same instrumentation that is used in surgery, obviating the need for laboratory conditions required for cadaveric dissection. Simulation is emerging as a mandatory component of surgical training. The egg is an excellent cost-effective model for drilling and dissection training and helps in improving surgical skills, enables learning of fine motor skills, and allows repeated practice. Although this method of training does help one control a drill and manual instrumentation, it does not help with temporal bone anatomy knowledge.

  6. Dynamics in mangroves assessed by high-resolution and multi-temporal satellite data: a case study in Zhanjiang Mangrove National Nature Reserve (ZMNNR), P. R. China

    NASA Astrophysics Data System (ADS)

    Leempoel, K.; Satyaranayana, B.; Bourgeois, C.; Zhang, J.; Chen, M.; Wang, J.; Bogaert, J.; Dahdouh-Guebas, F.

    2013-08-01

    Mangrove forests are declining across the globe, mainly because of human intervention, and therefore require an evaluation of their past and present status (e.g. areal extent, species-level distribution, etc.) to implement better conservation and management strategies. In this paper, mangrove cover dynamics at Gaoqiao (P. R. China) were assessed through time using 1967, 2000 and 2009 satellite imagery (sensors Corona KH-4B, Landsat ETM+, GeoEye-1 respectively). Firstly, multi-temporal analysis of satellite data was undertaken, and secondly biotic and abiotic differences were analysed between the different mangrove stands, assessed through a supervised classification of a high-resolution satellite image. A major decline in mangrove cover (-36%) was observed between 1967 and 2009 due to rice cultivation and aquaculture practices. Moreover, dike construction has prevented mangroves from expanding landward. Although a small increase of mangrove area was observed between 2000 and 2009 (+24%), the ratio mangrove / aquaculture kept decreasing due to increased aquaculture at the expense of rice cultivation in the vicinity. From the land-use/cover map based on ground-truth data (5 × 5 m plot-based tree measurements) (August-September, 2009) as well as spectral reflectance values (obtained from pansharpened GeoEye-1), both Bruguiera gymnorrhiza and small Aegiceras corniculatum are distinguishable at 73-100% accuracy, whereas tall A. corniculatum was correctly classified at only 53% due to its mixed vegetation stands with B. gymnorrhiza (overall classification accuracy: 85%). In the case of sediments, sand proportion was significantly different between the three mangrove classes. Overall, the advantage of very high resolution satellite images like GeoEye-1 (0.5 m) for mangrove spatial heterogeneity assessment and/or species-level discrimination was well demonstrated, along with the complexity to provide a precise classification for non-dominant species (e.g. Kandelia obovata

  7. Surgical management of osteoradionecrosis of the temporal bone

    SciTech Connect

    Kveton, J.F.

    1988-03-01

    The surgical management of osteoradionecrosis of the temporal bone has met with limited success because of the difficulty in accurate assessment of the viability of nonnecrotic bone intraoperatively. Failure to resect all nonviable bone results in recurrence of a necrotic focus. With the use of hyperbaric oxygen therapy to stabilize marginal bone and oral tetracycline to label viable bone preoperatively, removal of all nonviable bone can be accomplished. Postoperatively, a second course of hyperbaric therapy enhances wound healing, thus assuring a successful outcome. This article details a successful systematic approach that was developed to resect a necrotic focus in the temporal bone of a 10-year-old boy who had undergone a full course of radiotherapy for treatment of a rhabdomyosarcoma.

  8. Temporal response of bone to unloading

    SciTech Connect

    Globus, R.K.; Bikle, D.D.; Morey-Holton, E.

    1986-02-01

    A model of weightlessness in which the hindlimbs of rats are elevated by their tails at a 40 degrees angle to unload the hindlimbs while maintaining normal weight bearing on the forelimbs has been used to simulate certain conditions of space flight. When we used this model in growing rats, we found that growth in bone weight ceased by 1 week in the hindlimbs and lumbar vertebrae, whereas growth in bone weight in the forelimbs and cervical vertebrae remained unaffected. Within 2 weeks, however, the accretion of bone weight in the hindlimbs and lumbar vertebrae returned to normal despite continued skeletal unloading. Since bone weight in the growing rat is primarily determined by bone formation (bone resorption is modest), we investigated the effects of selective skeletal unloading on bone formation during 2 weeks of hindlimb elevation using radioisotope incorporation (with /sup 45/Ca and (/sup 3/H)proline) and histomorphometry (with tetracycline labeling). The studies using radioisotope incorporation showed that bone formation was inhibited by the fifth day of skeletal unloading. By the 10th to 12th day, bone formation had returned toward normal. In comparison with cortical bone, cancellous bone (lumbar vertebrae and proximal tibiae) incorporated more /sup 45/Ca and (/sup 3/H)proline (indicating greater metabolic activity) and had a greater absolute response to skeletal unloading. The results of these studies were confirmed by histomorphometric measurements of bone formation using triple tetracycline labeling. We conclude that this model of simulated weightlessness results in an initial inhibition of bone formation in the unloaded bones. This temporary cessation of bone formation is followed by a cessation in the accretion of bone weight, which then resumes at a normal rate by 14 days despite continued skeletal unloading.

  9. [CT findings of the temporal bones in Waardenburg's syndrome].

    PubMed

    Irie, K; Ogata, H; Mitsudome, A

    1990-05-01

    We reported three cases of Waardenburg's syndrome and discussed CT findings of the temporal bones. Two cases of these patients were mother and daughter. Case 1, a two-year-old girl, had lateral displacement of the medial canthi, a broad nasal root, hetero-chromic iridis, left ptosis, albinotic fundus, and bilateral congenital deafness. CT findings of the temporal bones showed enlarged vestibules, short lateral semicircular canal, and absent right posterior semicircular canal. The mother had congenital deafness, heterochromia iridis, and a white forelock and showed similar abnormal CT findings of the temporal bones. Case 2, a one-year-old boy, had lateral displacement of the medial canthi, a broad nasal root, partial heterochromia iridis, albinotic fundus, and bilateral congenital deafness. CT findings of the temporal bones showed enlarged vestibules and absence of semicircular canals except the right lateral semicircular canal. These cases were diagnosed as Waardenburg's syndrome on the basis of the characteristic features.

  10. Spatial and Temporal Controls on Concentration-Discharge Relationships in Intensively Managed Catchments: An Exploration of High-Resolution Nitrate Data from the U.S. Midwest

    NASA Astrophysics Data System (ADS)

    Van Meter, K. J.; Basu, N. B.

    2016-12-01

    Watersheds have been shown to demonstrate a range of both chemostatic and chemodynamic responses to changes in discharged based on land use, solute species and hydrologic regime as well as the presence or absence of large solute mass stores within the watershed. The dynamics of solute export, as captured by concentration-discharge patterns, have been described mathematically based on a power-law concentration discharge relationship of the form where a purely chemostatic system is characterized by a b value equal to 0. In practice, however, catchments across a range of land uses and geologic conditions as well may exhibit a distribution of solute export behaviors, and may exhibit both seasonal and interannual variability. It is our hypothesis that different solute export regimes are created primarily as a function of solute mass stores in different compartments of the landscape, e.g. the vadose zone or groundwater, and that these regimes may vary temporally based on the triggering of these compartments as a function of stochastic forcing within and between years. In the present work we synthesize high-resolution nitrate concentration data to better our understanding of the variations in concentration-discharge relationships as a function of land use, surface geology, climate and management controls. We then develop a parsimonious model to explain these patterns as a function not only of solute mass stores, but also of the triggering of fast and slow transport pathways across a range of precipitation dynamics. Specifically, we have developed a modeling framework to address the following questions: (1) How do C-Q relationships vary across climate and land-use gradients? (2) Is there any seasonality to C-Q patterns? (3) Can C-Q patterns be explained as a function of fast and slow hydrologic pathways in response to stochastic, hydro-climatic forcing? (4) How do these interactions lead to the development of hot spots and hot moments in catchment biogeochemical processing?

  11. Polarity and Temporality of High-Resolution Y-Chromosome Distributions in India Identify Both Indigenous and Exogenous Expansions and Reveal Minor Genetic Influence of Central Asian Pastoralists

    PubMed Central

    Sengupta, Sanghamitra; Zhivotovsky, Lev A.; King, Roy; Mehdi, S. Q.; Edmonds, Christopher A.; Chow, Cheryl-Emiliane T.; Lin, Alice A.; Mitra, Mitashree; Sil, Samir K.; Ramesh, A.; Usha Rani, M. V.; Thakur, Chitra M.; Cavalli-Sforza, L. Luca; Majumder, Partha P.; Underhill, Peter A.

    2006-01-01

    Although considerable cultural impact on social hierarchy and language in South Asia is attributable to the arrival of nomadic Central Asian pastoralists, genetic data (mitochondrial and Y chromosomal) have yielded dramatically conflicting inferences on the genetic origins of tribes and castes of South Asia. We sought to resolve this conflict, using high-resolution data on 69 informative Y-chromosome binary markers and 10 microsatellite markers from a large set of geographically, socially, and linguistically representative ethnic groups of South Asia. We found that the influence of Central Asia on the pre-existing gene pool was minor. The ages of accumulated microsatellite variation in the majority of Indian haplogroups exceed 10,000–15,000 years, which attests to the antiquity of regional differentiation. Therefore, our data do not support models that invoke a pronounced recent genetic input from Central Asia to explain the observed genetic variation in South Asia. R1a1 and R2 haplogroups indicate demographic complexity that is inconsistent with a recent single history. Associated microsatellite analyses of the high-frequency R1a1 haplogroup chromosomes indicate independent recent histories of the Indus Valley and the peninsular Indian region. Our data are also more consistent with a peninsular origin of Dravidian speakers than a source with proximity to the Indus and with significant genetic input resulting from demic diffusion associated with agriculture. Our results underscore the importance of marker ascertainment for distinguishing phylogenetic terminal branches from basal nodes when attributing ancestral composition and temporality to either indigenous or exogenous sources. Our reappraisal indicates that pre-Holocene and Holocene-era—not Indo-European—expansions have shaped the distinctive South Asian Y-chromosome landscape. PMID:16400607

  12. Polarity and temporality of high-resolution y-chromosome distributions in India identify both indigenous and exogenous expansions and reveal minor genetic influence of Central Asian pastoralists.

    PubMed

    Sengupta, Sanghamitra; Zhivotovsky, Lev A; King, Roy; Mehdi, S Q; Edmonds, Christopher A; Chow, Cheryl-Emiliane T; Lin, Alice A; Mitra, Mitashree; Sil, Samir K; Ramesh, A; Usha Rani, M V; Thakur, Chitra M; Cavalli-Sforza, L Luca; Majumder, Partha P; Underhill, Peter A

    2006-02-01

    Although considerable cultural impact on social hierarchy and language in South Asia is attributable to the arrival of nomadic Central Asian pastoralists, genetic data (mitochondrial and Y chromosomal) have yielded dramatically conflicting inferences on the genetic origins of tribes and castes of South Asia. We sought to resolve this conflict, using high-resolution data on 69 informative Y-chromosome binary markers and 10 microsatellite markers from a large set of geographically, socially, and linguistically representative ethnic groups of South Asia. We found that the influence of Central Asia on the pre-existing gene pool was minor. The ages of accumulated microsatellite variation in the majority of Indian haplogroups exceed 10,000-15,000 years, which attests to the antiquity of regional differentiation. Therefore, our data do not support models that invoke a pronounced recent genetic input from Central Asia to explain the observed genetic variation in South Asia. R1a1 and R2 haplogroups indicate demographic complexity that is inconsistent with a recent single history. Associated microsatellite analyses of the high-frequency R1a1 haplogroup chromosomes indicate independent recent histories of the Indus Valley and the peninsular Indian region. Our data are also more consistent with a peninsular origin of Dravidian speakers than a source with proximity to the Indus and with significant genetic input resulting from demic diffusion associated with agriculture. Our results underscore the importance of marker ascertainment for distinguishing phylogenetic terminal branches from basal nodes when attributing ancestral composition and temporality to either indigenous or exogenous sources. Our reappraisal indicates that pre-Holocene and Holocene-era--not Indo-European--expansions have shaped the distinctive South Asian Y-chromosome landscape.

  13. Temporal Bone Histopathology in NOG-Symphalangism Spectrum Disorder

    PubMed Central

    Quesnel, Alicia M.; Nadol, Joseph B.; Nielsen, G. Petur; Curtin, Hugh D.; Lesperance, Marci M.

    2015-01-01

    Objective To describe the human temporal bone histopathology in NOG-related Symphalangism Spectrum Disorder, a spectrum of congenital stapes fixation syndromes caused by mutations in the NOG gene. To discuss implications for clinical management. Patient A patient with a mutation in the NOG gene Intervention(s) Removal of temporal bones, post-mortem temporal bone computed tomography, histologic processing and review of temporal bones Main Outcome Measure(s) Temporal bone histopathology, and correlation with clinical, genetic, audiologic, and radiologic evaluations Results Both temporal bones demonstrated fixation of the stapes footplate to the otic capsule due to a circumferential bridge of calcified cartilage. In the right ear (unoperated), there was no additional abnormality of the ossicles or ossicular joints. In the left ear, fenestrations of the stapes footplate and the lateral semicircular canal were seen, consistent with a history of stapedectomy and fenestration procedure. Severe loss of spiral ganglion neurons (SGN) throughout the left cochlea accounted for the profound sensorineural hearing loss; there was a normal number of SGN in the right ear. In both ears, the cochleae demonstrated grossly preserved organs of Corti. Conclusion The temporal bone pathologic correlate for conductive hearing loss in this patient with a NOG mutation was circumferentially calcified cartilage bridging the stapedo-vestibular joint space. The temporal bone histopathology findings suggest that conductive hearing loss related to NOG mutation should be improved after stapedectomy; however, care must be taken in extrapolating to all patients with NOG mutations, as there may be variability in the pathology, especially given the variability of NOG spectrum disorders. PMID:26474326

  14. The temporal response of bone to unloading

    NASA Technical Reports Server (NTRS)

    Globus, R. K.; Bikle, D. D.; Morey-Holton, E.

    1984-01-01

    Rats were suspended by their tails with the forelimbs bearing the weight load to simulate the weightlessness of space flight. Growth in bone mass ceased by 1 week in the hindlimbs and lumbar vertebrae in growing rats, while growth in the forelimbs and cervical vertebrae remained unaffected. The effects of selective skeletal unloading on bone formation during 2 weeks of suspension was investigated using radio iostope incorporation (with Ca-45 and H-3 proline) and histomorphometry (with tetracycline labeling). The results of these studies were confirmed by histomorphometric measurements of bone formation using triple tetracycline labeling. This model of simulated weightlessness results in an initial inhibition of bone formation in the unloaded bones. This temporary cessation of bone formation is followed in the accretion of bone mass, which then resumes at a normal rate by 14 days, despite continued skeletal unloading. This cycle of inhibition and resumption of bone formation has profound implication for understanding bone dynamics durng space flight, immobilization, or bed rest and offers an opportunity to study the hormonal and mechanical factors that regulate bone formation.

  15. 3D assessment of cortical bone porosity and tissue mineral density using high-resolution µCT: effects of resolution and threshold method.

    PubMed

    Palacio-Mancheno, Paolo E; Larriera, Adriana I; Doty, Stephen B; Cardoso, Luis; Fritton, Susannah P

    2014-01-01

    Current micro-computed tomography (µCT) systems allow scanning bone at resolutions capable of three-dimensional (3D) characterization of intracortical vascular porosity and osteocyte lacunae. However, the scanning and reconstruction parameters along with the image segmentation method affect the accuracy of the measurements. In this study, the effects of scanning resolution and image threshold method in quantifying small features of cortical bone (vascular porosity, vascular canal diameter and separation, lacunar porosity and density, and tissue mineral density) were analyzed. Cortical bone from the tibia of Sprague-Dawley rats was scanned at 1-µm and 4-µm resolution, reconstructions were density-calibrated, and volumes of interest were segmented using approaches based on edge-detection or histogram analysis. In 1-µm resolution scans, the osteocyte lacunar spaces could be visualized, and it was possible to separate the lacunar porosity from the vascular porosity. At 4-µm resolution, the vascular porosity and vascular canal diameter were underestimated, and osteocyte lacunae were not effectively detected, whereas the vascular canal separation and tissue mineral density were overestimated compared to 1-µm resolution. Resolution had a much greater effect on the measurements than did threshold method, showing partial volume effects at resolutions coarser than 2 µm in two separate analyses, one of which assessed the effect of resolution on an object of known size with similar architecture to a vascular pore. Although there was little difference when using the edge-detection versus histogram-based threshold approaches, edge-detection was somewhat more effective in delineating canal architecture at finer resolutions (1-2 µm). In addition, use of a high-resolution (1 µm) density-based threshold on lower resolution (4 µm) density-calibrated images was not effective in improving the lower-resolution measurements. In conclusion, if measuring cortical vascular

  16. A New Hybrid Spatio-temporal Model for Estimating Daily Multi-year PM2.5 Concentrations Across Northeastern USA Using High Resolution Aerosol Optical Depth Data

    NASA Technical Reports Server (NTRS)

    Kloog, Itai; Chudnovsky, Alexandra A.; Just, Allan C.; Nordio, Francesco; Koutrakis, Petros; Coull, Brent A.; Lyapustin, Alexei; Wang, Yujie; Schwartz, Joel

    2014-01-01

    The use of satellite-based aerosol optical depth (AOD) to estimate fine particulate matter PM(sub 2.5) for epidemiology studies has increased substantially over the past few years. These recent studies often report moderate predictive power, which can generate downward bias in effect estimates. In addition, AOD measurements have only moderate spatial resolution, and have substantial missing data. We make use of recent advances in MODIS satellite data processing algorithms (Multi-Angle Implementation of Atmospheric Correction (MAIAC), which allow us to use 1 km (versus currently available 10 km) resolution AOD data.We developed and cross validated models to predict daily PM(sub 2.5) at a 1X 1 km resolution across the northeastern USA (New England, New York and New Jersey) for the years 2003-2011, allowing us to better differentiate daily and long term exposure between urban, suburban, and rural areas. Additionally, we developed an approach that allows us to generate daily high-resolution 200 m localized predictions representing deviations from the area 1 X 1 km grid predictions. We used mixed models regressing PM(sub 2.5) measurements against day-specific random intercepts, and fixed and random AOD and temperature slopes. We then use generalized additive mixed models with spatial smoothing to generate grid cell predictions when AOD was missing. Finally, to get 200 m localized predictions, we regressed the residuals from the final model for each monitor against the local spatial and temporal variables at each monitoring site. Our model performance was excellent (mean out-of-sample R(sup 2) = 0.88). The spatial and temporal components of the out-of-sample results also presented very good fits to the withheld data (R(sup 2) = 0.87, R(sup)2 = 0.87). In addition, our results revealed very little bias in the predicted concentrations (Slope of predictions versus withheld observations = 0.99). Our daily model results show high predictive accuracy at high spatial resolutions

  17. A New Hybrid Spatio-Temporal Model For Estimating Daily Multi-Year PM2.5 Concentrations Across Northeastern USA Using High Resolution Aerosol Optical Depth Data

    PubMed Central

    Kloog, Itai; Chudnovsky, Alexandra A.; Just, Allan C.; Nordio, Francesco; Koutrakis, Petros; Coull, Brent A.; Lyapustin, Alexei; Wang, Yujie; Schwartz, Joel

    2017-01-01

    Background The use of satellite-based aerosol optical depth (AOD) to estimate fine particulate matter (PM2.5) for epidemiology studies has increased substantially over the past few years. These recent studies often report moderate predictive power, which can generate downward bias in effect estimates. In addition, AOD measurements have only moderate spatial resolution, and have substantial missing data. Methods We make use of recent advances in MODIS satellite data processing algorithms (Multi-Angle Implementation of Atmospheric Correction (MAIAC), which allow us to use 1 km (versus currently available 10 km) resolution AOD data. We developed and cross validated models to predict daily PM2.5 at a 1×1km resolution across the northeastern USA (New England, New York and New Jersey) for the years 2003–2011, allowing us to better differentiate daily and long term exposure between urban, suburban, and rural areas. Additionally, we developed an approach that allows us to generate daily high-resolution 200 m localized predictions representing deviations from the area 1×1 km grid predictions. We used mixed models regressing PM2.5 measurements against day-specific random intercepts, and fixed and random AOD and temperature slopes. We then use generalized additive mixed models with spatial smoothing to generate grid cell predictions when AOD was missing. Finally, to get 200 m localized predictions, we regressed the residuals from the final model for each monitor against the local spatial and temporal variables at each monitoring site. Results Our model performance was excellent (mean out-of-sample R2=0.88). The spatial and temporal components of the out-of-sample results also presented very good fits to the withheld data (R2=0.87, R2=0.87). In addition, our results revealed very little bias in the predicted concentrations (Slope of predictions versus withheld observations = 0.99). Conclusion Our daily model results show high predictive accuracy at high spatial resolutions

  18. Assessment of bone microarchitecture in chronic kidney disease: a comparison of 2D bone texture analysis and high-resolution peripheral quantitative computed tomography at the radius and tibia.

    PubMed

    Bacchetta, Justine; Boutroy, Stéphanie; Vilayphiou, Nicolas; Fouque-Aubert, Anne; Delmas, Pierre D; Lespessailles, Eric; Fouque, Denis; Chapurlat, Roland

    2010-11-01

    Bone microarchitecture can be studied noninvasively using high-resolution peripheral quantitative computed tomography (HR-pQCT). However, this technique is not widely available, so more simple techniques may be useful. BMA is a new 2D high-resolution digital X-ray device, allowing for bone texture analysis with a fractal parameter (H(mean)). The aims of this study were (1) to evaluate the reproducibility of BMA at two novel sites (radius and tibia) in addition to the conventional site (calcaneus), (2) to compare the results obtained with BMA at all of those sites, and (3) to study the relationship between H(mean) and trabecular microarchitecture measured with an in vivo 3D device (HR-pQCT) at the distal tibia and radius. BMA measurements were performed at three sites (calcaneus, distal tibia, and radius) in 14 healthy volunteers to measure the short-term reproducibility and in a group of 77 patients with chronic kidney disease to compare BMA results to HR-pQCT results. The coefficient of variation of H(mean) was 1.2, 2.1, and 4.7% at the calcaneus, radius, and tibia, respectively. We found significant associations between trabecular volumetric bone mineral density and microarchitectural variables measured by HR-pQCT and H(mean) at the three sites (e.g., Pearson correlation between radial trabecular number and radial H(mean) r = 0.472, P < 0.001). This study demonstrated a significant but moderate relationship between 2D bone texture and 3D trabecular microarchitecture. BMA is a new reproducible technique with few technical constraints. Thus, it may represent an interesting tool for evaluating bone structure, in association with biological parameters and DXA.

  19. Virtual Temporal Bone Dissection System: Development and Testing

    PubMed Central

    Wiet, Gregory J.; Stredney, Don; Kerwin, Thomas; Hittle, Bradley; Fernandez, Soledad A.; Welling, D. Bradley

    2012-01-01

    Objectives/Hypothesis The objective of this project was to develop a virtual temporal bone dissection system that would provide an enhanced educational experience for the training of otologic surgeons. Study Design A randomized, controlled, multi-institutional single blinded validation study. Methods The project encompassed 4 areas of emphasis: structural data acquisition, integration of the system, dissemination of the system, and validation. Results Structural acquisition was performed on multiple imaging platforms. Integration achieved a cost effective system. Dissemination was achieved on different levels including casual interest, downloading of software, and full involvement in development and validation studies. A validation study was performed at 8 different training institutions across the country using a two arm, randomized trial where study subjects were randomized to a two-week practice session using either the virtual temporal bone or standard cadaveric temporal bones. Eighty subjects were enrolled and randomized to one of the two treatment arms, 65 completed the study. There was no difference between the two groups using a blinded rating tool to assess performance after training. Conclusions 1. A virtual temporal bone dissection system has been developed and compared to cadaveric temporal bones for practice using a multi-center trial. 2. There is no statistical difference seen between practice on the current simulator when compared to practice on human cadaveric temporal bones. 3. Further refinements in structural acquisition and interface design have been identified which can be implemented prior to full incorporation into training programs and use for objective skills assessment. PMID:22294268

  20. Chondroblastoma of the temporal bone: consistent middle fossa involvement.

    PubMed

    Selesnick, S H; Levine, J M

    1999-01-01

    The objective of this study is to describe the presentation and clinical course of two patients with temporal bone chondroblastoma, and to review the literature on temporal bone chondroblastoma to identify characteristic clinical and radiological presentations, and optimal treatment regimens. MEDLINE literature searches covering the period from 1966 to January 1998, in all languages, were performed as well as a review of the bibliographies of the identified studies. Strict inclusion criteria were upheld, In total 18 studies had patients whose data could be analyzed. From the 18 studies, 34 patients were identified, but only 21 cases met the inclusion criteria. Demographic, clinical presentation, radiological, operative and treatment parameters were analyzed in this cohort of patients. Ninety-five percent of patients were found to have invasion of the middle cranial fossa and 76% were found to have erosion into the superior aspect of the external auditory canal by temporal bone chondroblastoma. The characteristic growth pattern of temporal bone chondroblastoma may result from embryonal or cartilagenous rests entrapped in the tympanosquamous suture line in the middle fossa floor. Temporal bone chondroblastoma represents a pathology that does not arise from, or have a growth pattern resembling other pathologies in the temporal bone.

  1. Bilateral Non-Hodgkin's Lymphoma of the Temporal Bone: A Rare and Unusual Presentation

    PubMed Central

    Jadhav, Jyoti; Chandorkar, Aparna

    2016-01-01

    Primary lymphoma of the temporal bone is an unusual finding in clinical practice and bilateral affection is even more rare. To the best of our knowledge, there are no reports of bilateral primary temporal bone lymphoma without middle ear involvement in the English medical literature so far. We report, for the first time, a case of primary lymphoma involving both temporal bones which presented with left-sided infranuclear facial palsy. A combination of contrast enhanced magnetic resonance imaging (MRI) and high resolution computed tomography (HRCT) was used to characterize and to map the extent of the lesion, as well as to identify the exact site of facial nerve affection. An excision biopsy and immunohistochemistry revealed diffuse large B-cell non-Hodgkin's lymphoma (DLBCL). Whole body fluorodeoxyglucose (FDG) positron emission tomography-computed tomography study (PET-CT) was performed to stage the disease. The patient was treated with chemotherapy and radiation therapy and is now on regular follow-up. The patient is alive and asymptomatic without disease progression for the last twenty months after initial diagnosis. PMID:28116198

  2. 3D Assessment of Cortical Bone Porosity and Tissue Mineral Density Using High-Resolution Micro-CT: Effects of Resolution and Threshold Method

    PubMed Central

    Palacio-Mancheno, Paolo E.; Larriera, Adriana I.; Doty, Stephen B.; Cardoso, Luis; Fritton, Susannah P.

    2013-01-01

    Current micro-CT systems allow scanning bone at resolutions capable of three-dimensional characterization of intracortical vascular porosity and osteocyte lacunae. However, the scanning and reconstruction parameters along with the image segmentation method affect the accuracy of the measurements. In this study, the effects of scanning resolution and image threshold method in quantifying small features of cortical bone (vascular porosity, vascular canal diameter and separation, lacunar porosity and density, and tissue mineral density) were analyzed. Cortical bone from the tibia of Sprague-Dawley rats was scanned at 1-µm and 4-µm resolutions, reconstructions were density-calibrated, and volumes of interest were segmented using approaches based on edge-detection or histogram analysis. With 1-µm resolution scans, the osteocyte lacunar spaces could be visualized, and it was possible to separate the lacunar porosity from the vascular porosity. At 4-µm resolution, the vascular porosity and vascular canal diameter were underestimated, and osteocyte lacunae were not effectively detected, whereas the vascular canal separation and tissue mineral density were overestimated compared to 1-µm resolution. Resolution had a much greater effect on the measurements than did threshold method, with partial volume effects at resolutions coarser than 2 µm demonstrated in two separate analyses, one of which assessed the effect of resolution on an object of known size with similar architecture to a vascular pore. Although there was little difference when using the edge-detection versus histogram-based threshold approaches, edge-detection was somewhat more effective in delineating canal architecture at finer resolutions (1 – 2 µm). In addition, use of a high-resolution (1-µm) density-based threshold on lower resolution (4-µm) density-calibrated images was not effective in improving the lower-resolution measurements. In conclusion, if measuring cortical vascular microarchitecture

  3. Final Technical Report for "High-resolution temporal variations in groundwater chemistry: Tracing the links between climate, hydrology, and element mobility in the vadose zone"

    SciTech Connect

    Jay L. Banner

    2002-04-23

    In spite of a developing emphasis on geochemical methods in studies of modern hydrologic systems, there have been few attempts to examine temporal fluctuations in groundwater chemistry and element mobility in the near-surface environment. Relatively little is known regarding how groundwaters evolve over 10 to 10,000 year scales, yet this knowledge provides a critical framework for understanding the links between climate and hydrology, the evolution of soils, and element migration in the vadose environment. Recent analytical advances allow U-series measurements to be applied to developing high-resolution chronologies of Pleistocene and Holocene carbonates. The potential of these new tools is examined through an analysis of two well-defined, active karst systems in (1) Barbados and (2) Texas. (1) The research effort on Barbados has developed methods of estimating recharge and inferring the spatial and seasonal distribution of recharge to the Pleistocene limestone aquifer on Barbados. A new method has been developed to estimate recharge based on oxygen isotope variations in rainwater and groundwater. Inter-annual recharge variations indicate that recharge is dependent on the distribution of rainfall throughout the year rather than total annual rainfall. Consequently, a year when rainfall occurs primarily during the peak wet season months (August through November) may have more recharge than a year when rainfall is more evenly distributed through the year. These results lay important groundwork for analysis of rainfall/recharge variations over different time scales based on isotopic records presently being constructed using Barbados speleothems from the same aquifer. (2) The chronology of speleothems (cave calcite deposits) from three caves across 130 kilometers in central Texas provides a 71,000-year record of temporal changes in hydrology and climate. Fifty-three ages were determined by mass spectrometric 238U - 230Th and 235U - 231Pa analyses. The accuracy of the

  4. Malignant tumors of the temporal bone - our experience.

    PubMed

    da Silva, Ana Pereira; Breda, Eduardo; Monteiro, Eurico

    2016-01-01

    Malignant tumors of the temporal bone are rare, with an estimated incidence of about 0.8-1.0 per 1,000,000 inhabitants per year. The vast majority of these tumors are squamous cell carcinomas and their treatment is eminently surgical. This study is an attempt at systematizing the forms of clinical presentation, the therapeutic possibilities, and oncological outcomes of patients with malignant tumors of the temporal bone in a tertiary hospital in Portugal. The authors present a retrospective study of temporal bone tumors treated and followed during otorhinolaryngology consultations between 2004 and 2014. A review of the literature is also included. Of the 18 patients included in the study, 16 had a primary tumor of the temporal bone, in most cases with squamous cell carcinoma histology. Of these, 13 patients were treated with curative intent that always included the surgical approach. Disease persistence was observed in one patient and local recurrence in five patients, on average 36.8 months after the initial treatment. The anatomical complexity of the temporal bone and the close associations with vital structures make it difficult to perform tumor resection with margins of safety and thus, tumor relapses are almost always local. A high level of suspicion is crucial for early diagnosis, and stringent and prolonged follow-up after treatment is essential for diagnosis and timely treatment of recurrances. Copyright © 2015 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  5. Imaging Modality of Choice for Pre-Operative Cochlear Imaging: HRCT vs. MRI Temporal Bone

    PubMed Central

    Solanki, Rajendra N.; Shah, Dipali C.; Vishwakarma, Rajesh; Kumar, Sandeep

    2016-01-01

    Introduction Congenital inner ear malformations occur as a result of the arrest or aberrance of inner ear development due to the heredity, gene mutation or other factors. Ever since the availability of cochlear implants, pre-operative evaluation by imaging of temporal bone has gained much attention. Precise selection of the candidate for cochlear implant dependent on preoperative radiological investigations. Only CT (Computed Tomography) and MRI (Magnetic Resonance Imaging) can provide a better picture of anatomy and pathology. Aim To compare pre-operative imaging findings of both MRI and High Resolution Computed Tomography (HRCT) temporal bone and to find the best modality of choice in patients with bilateral profound Sensorineural Hearing Loss (SNHL). Materials and Methods This was a prospective, longitudinal, observational study conducted between June 2010 to November 2012. A total of 144 temporal bones were evaluated in 72 children with bilateral profound SNHL with congenital inner ear malformations. Each temporal bone was considered as a single case (144 cases). All the patients underwent HRCT and high field MRI study. MRI study included T2 W axial 3D FIESTA (Fast Imaging Employing Steady-state Acquisition) sequence. Anatomic abnormalities in each temporal bone were described and noted. For complete and better evaluation of Vestibulo-Cochlear Nerve (VCN) additional 3D oblique parasagittal view was taken perpendicular to the internal auditory canal with a small Field Of View (FOV). Results HRCT and MRI allowed accurate detection of inner ear malformations in children with bilateral SNHL. Majority of the patients presented with multiple structural abnormalities of inner ear. The common pathologies detected in the study were semicircular canal abnormality (89/144) followed by cochlear abnormalities (39/144). Most common cochlear abnormality was Mondini’s deformity (14/144). MRI demonstrated absent of vestibulo-cochlear nerve in 15 cases. Conclusion Few

  6. Contralateral Cochlear Labyrinthine Concussion without Temporal Bone Fracture: Unusual Posttraumatic Consequence

    PubMed Central

    Méndez, D.; Silva, J. M. Duque; del Álamo, P. Ortega

    2016-01-01

    Introduction. Labyrinthine concussion is a term used to describe a rare cause of sensorineural hearing loss with or without vestibular symptoms occurring after head trauma. Isolated damage to the inner ear without involving the vestibular organ would be designated as a cochlear labyrinthine concussion. Hearing loss is not a rare finding in head trauma that involves petrous bone fractures. Nevertheless it generally occurs ipsilateral to the side of the head injury and extraordinarily in the contralateral side and moreover without the presence of a fracture. Case Report. The present case describes a 37-year-old patient with sensorineural hearing loss and tinnitus in his right ear after a blunt head trauma of the left-sided temporal bone (contralateral). Otoscopy and radiological images showed no fractures or any abnormalities. A severe sensorineural hearing loss was found in his right ear with a normal hearing of the left side. Conclusion. The temporal bone trauma requires a complete diagnostic battery which includes a neurotologic examination and a high resolution computed tomography scan in the first place. Hearing loss after a head injury extraordinarily occurs in the contralateral side of the trauma as what happened in our case. In addition, the absence of fractures makes this phenomenon even more unusual. PMID:27738540

  7. Massive Cerebrospinal Fluid Leak of the Temporal Bone

    PubMed Central

    Manno, Alessandra; Pasqualitto, Emanuela; Ciofalo, Andrea; Angeletti, Diletta; Pasquariello, Benedetta

    2016-01-01

    Cerebrospinal fluid (CSF) leakage of the temporal bone region is defined as abnormal communications between the subarachnoidal space and the air-containing spaces of the temporal bone. CSF leak remains one of the most frequent complications after VS surgery. Radiotherapy is considered a predisposing factor for development of temporal bone CSF leak because it may impair dural repair mechanisms, thus causing inadequate dural sealing. The authors describe the case of a 47-year-old man with a massive effusion of CSF which extended from the posterior and lateral skull base to the first cervical vertebrae; this complication appeared after a partial enucleation of a vestibular schwannoma (VS) with subsequent radiation treatment and second operation with total VS resection. PMID:27597915

  8. Massive Cerebrospinal Fluid Leak of the Temporal Bone.

    PubMed

    Iannella, Giannicola; Manno, Alessandra; Pasqualitto, Emanuela; Ciofalo, Andrea; Angeletti, Diletta; Pasquariello, Benedetta; Magliulo, Giuseppe

    2016-01-01

    Cerebrospinal fluid (CSF) leakage of the temporal bone region is defined as abnormal communications between the subarachnoidal space and the air-containing spaces of the temporal bone. CSF leak remains one of the most frequent complications after VS surgery. Radiotherapy is considered a predisposing factor for development of temporal bone CSF leak because it may impair dural repair mechanisms, thus causing inadequate dural sealing. The authors describe the case of a 47-year-old man with a massive effusion of CSF which extended from the posterior and lateral skull base to the first cervical vertebrae; this complication appeared after a partial enucleation of a vestibular schwannoma (VS) with subsequent radiation treatment and second operation with total VS resection.

  9. Evaluation of Software Tools for Segmentation of Temporal Bone Anatomy.

    PubMed

    Hassan, Kowther; Dort, Joseph C; Sutherland, Garnette R; Chan, Sonny

    2016-01-01

    Surgeons are increasingly relying on 3D medical image data for planning interventions. Virtual 3D models of intricate anatomy, such as that found within the temporal bone, have proven useful for surgical education, planning, and rehearsal, but such applications require segmentation of surgically relevant structures in the image data. Four publicly available software packages, ITK-SNAP, MITK, 3D Slicer, and Seg3D, were evaluated for their efficacy in segmenting temporal bone anatomy from CT and MR images to support patient-specific surgery simulation. No single application provided efficient means to segment every structure, but a combination of the tools evaluated enables creation of a complete virtual temporal bone model from raw image data with reasonably minimal effort.

  10. Human Temporal Bone Removal: The Skull Base Block Method.

    PubMed

    Dinh, Christine; Szczupak, Mikhaylo; Moon, Seo; Angeli, Simon; Eshraghi, Adrien; Telischi, Fred F

    2015-08-01

    Objectives To describe a technique for harvesting larger temporal bone specimens from human cadavers for the training of otolaryngology residents and fellows on the various approaches to the lateral and posterolateral skull base. Design Human cadaveric anatomical study. The calvarium was excised 6 cm above the superior aspect of the ear canal. The brain and cerebellum were carefully removed, and the cranial nerves were cut sharply. Two bony cuts were performed, one in the midsagittal plane and the other in the coronal plane at the level of the optic foramen. Setting Medical school anatomy laboratory. Participants Human cadavers. Main Outcome Measures Anatomical contents of specimens and technical effort required. Results Larger temporal bone specimens containing portions of the parietal, occipital, and sphenoidal bones were consistently obtained using this technique of two bone cuts. All specimens were inspected and contained pertinent surface and skull base landmarks. Conclusions The skull base block method allows for larger temporal bone specimens using a two bone cut technique that is efficient and reproducible. These specimens have the necessary anatomical bony landmarks for studying the complexity, utility, and limitations of lateral and posterolateral approaches to the skull base, important for the education of otolaryngology residents and fellows.

  11. High Resolution Computed Tomography

    DTIC Science & Technology

    1992-07-31

    samples. 14. SUBJECTTERMS 15. NUMBER OF PAGES 38 High Resolution, Microfocus , Characterization, X - Ray , Micrography, Computed Tomography (CT), Failure...high resolutions (50 g.tm feature sensitivity) when a small field of view (50 mm) is used [11]. Specially designed detectors and a microfocus X - ray ...Wright Laboratories. Feldkamp [14] at Ford used a microfocus X - ray source and an X - ray image intensifier to develop a system capable of 20 g.m

  12. Three-dimensional modeling of the temporal bone for surgical training.

    PubMed

    Bakhos, David; Velut, Stéphane; Robier, Alain; Al zahrani, Musaed; Lescanne, Emmanuel

    2010-02-01

    The anatomy of the temporal bone (TB) can only be mastered by repeated surgical and anatomic dissections, and surgical teaching initiative had a major effect on outcomes. The aim of this study was to investigate the validity of an artificial TB model devoted to surgical training and education. A helical computed tomographic (CT) scan was used to acquire high-resolution data of cadaveric TB. Digital imaging and communications in medicine (DICOM) data were converted into.stl files after data processing. Cadaveric TBs were prototyped using stereolithography. The validation of the prototype needed several steps. First of all, we have studied on CT scan the positional relationship between the facial nerve and other structures of the cadaveric TBs and prototyped bones. Otoendoscopy of the middle ear and the internal acoustic canal and visualization of anatomic landmarks during TB drilling of the cadaveric TBs and prototyped bones were also performed. Seven normal CT scans of cadaveric TB were selected to make prototyped bone using stereolithography. Measurements of volume and distance showed no significant difference between prototypes and cadaver TBs. Classic mastoid surgical procedures were performed in the Anatomy Department: exposing sigmoid sinus, facial nerve, labyrinth, dura mater, jugular bulb, and internal carotid artery. Two simulations of implantable middle ear prosthesis were made successfully. These prototypes made using stereolithography seem to be a good anatomic model for surgical training. This model could also be interesting for surgical planning in congenital ear anomalies before middle ear prosthesis implantation.

  13. High-resolution MRI vessel wall imaging: spatial and temporal patterns of reversible cerebral vasoconstriction syndrome and central nervous system vasculitis.

    PubMed

    Obusez, E C; Hui, F; Hajj-Ali, R A; Cerejo, R; Calabrese, L H; Hammad, T; Jones, S E

    2014-08-01

    High-resolution MR imaging is an emerging tool for evaluating intracranial artery disease. It has an advantage of defining vessel wall characteristics of intracranial vascular diseases. We investigated high-resolution MR imaging arterial wall characteristics of CNS vasculitis and reversible cerebral vasoconstriction syndrome to determine wall pattern changes during a follow-up period. We retrospectively reviewed 3T-high-resolution MR imaging vessel wall studies performed on 26 patients with a confirmed diagnosis of CNS vasculitis and reversible cerebral vasoconstriction syndrome during a follow-up period. Vessel wall imaging protocol included black-blood contrast-enhanced T1-weighted sequences with fat suppression and a saturation band, and time-of-flight MRA of the circle of Willis. Vessel wall characteristics including enhancement, wall thickening, and lumen narrowing were collected. Thirteen patients with CNS vasculitis and 13 patients with reversible cerebral vasoconstriction syndrome were included. In the CNS vasculitis group, 9 patients showed smooth, concentric wall enhancement and thickening; 3 patients had smooth, eccentric wall enhancement and thickening; and 1 patient was without wall enhancement and thickening. Six of 13 patients had follow-up imaging; 4 patients showed stable smooth, concentric enhancement and thickening; and 2 patients had resoluton of initial imaging findings. In the reversible cerebral vasoconstriction syndrome group, 10 patients showed diffuse, uniform wall thickening with negligible-to-mild enhancement. Nine patients had follow-up imaging, with 8 patients showing complete resolution of the initial findings. Postgadolinium 3T-high-resolution MR imaging appears to be a feasible tool in differentiating vessel wall patterns of CNS vasculitis and reversible cerebral vasoconstriction syndrome changes during a follow-up period. © 2014 by American Journal of Neuroradiology.

  14. Cost effective use of audiograms after pediatric temporal bone fractures.

    PubMed

    Frisenda, Julia L; Schroeder, James W; Ryan, Maura E; Valika, Taher S; Billings, Kathleen R

    2015-11-01

    To identify the relationship of pediatric temporal fractures to the incidence and type of hearing loss present. To analyze the timing and utility of audiometric testing in children with temporal bone fractures. Retrospective case series of 50 pediatric patients with temporal bone fractures who were treated at an urban, tertiary care children's hospital from 2008 to 2014. A statistical analysis of predictors of hearing loss after temporal bone fracture was performed. Fifty-three fractures (69.7%) in 50 patients involved the petrous portion of the temporal bone. The mean age of patients was 7.13 years, and 39 (73.6%) were male. A fall was the most common mechanism of injury in 28 (52.8%) patients, followed by crush injury (n=14, 26.2%), and vehicular trauma (n=10, 18.9%). All otic capsule violating fractures were associated with a sensorineural hearing loss (n=4, 7.5%, p=0.002). Three of four otic capsule sparing fractures were associated with ossicular dislocation, with a corresponding mixed or conductive hearing loss on follow up audiometric testing. The majority of otic capsule sparing fracture patients (n=19/43, 44.2%) who had follow up audiograms had normal hearing, and those with otic capsule violating fractures were statistically more likely to have persistent hearing loss than those with otic capsule sparing fractures (p=0.01). Patients with otic capsule violating fractures or those with ossicular disruption are at higher risk for persistent hearing loss. Cost-saving may be accrued by selecting only those patients at high risk for persistent hearing loss for audiometric testing after temporal bone fractures. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  15. Temporal bone verrucous carcinoma: outcomes and treatment controversy

    PubMed Central

    Martin, Neil; Juillard, Guy F.; Bhuta, Sunita; Ishiyama, Akira

    2010-01-01

    Verrucous carcinoma is a rare tumor that presents in the head and neck with the most common sites being the oral cavity and larynx. Fourteen cases of verrucous carcinoma of the temporal bone have been described in literature; this study aims to examine treatment outcomes and discuss the controversy surrounding postoperative radiation. The study design included a literature review along with individual case report in the setting of a tertiary care medical center. Outcome analysis of all cases of verrucous carcinoma of the temporal bone, which are documented in the English literature, and presentation of a single patient report including gross, histologic and radiologic analyses were performed. The longest recorded survival for verrucous carcinoma of the temporal bone occurs in patients treated with surgery alone. Poorer outcomes for patients treated with adjuvant (chemo)radiation may be due to more advanced stage of disease at the time of treatment. Early reports of radiation leading to tumor dedifferentiation or early recurrence are not supported by more recent studies. Whether adjuvant radiation therapy is indicated in verrucous carcinoma of the temporal bone remains controversial. PMID:20502907

  16. Giant Cell Reparative Granuloma of the Petrous Temporal Bone

    PubMed Central

    Williams, Joy C.; Thorell, William E.; Treves, John S.; Fidler, Mary E.; Moore, Gary F.; Leibrock, Lyal G.

    2000-01-01

    Giant cell reparative granuloma (GCRG) is an unusual, benign bone lesion that most commonly affects the maxilla and mandible; skull involvement is rare. The etiology is uncertain but may be related to trauma. GCRG is difficult to distinguish from giant cell tumor of the bone and has a lower recurrence rate. Thirteen reports of temporal bone GCRG in 11 patients have been reported. One report of a petrous GCRG in a 3-year-old girl has been identified. A 38-year-old male presented with a 2-year history of fullness in his left ear, ipsilateral hearing loss, and intermittent cacosmia. Computed tomography and magnetic resonance imaging revealed a large left-sided anterior temporal extradural mass. The patient underwent a left frontotemporal craniotomy and resection of a left temporal fossa tumor that involved the petrous and squamous parts of the temporal bone. The patient's post-operative course was uneventful, except for increased hearing loss secondary to opening of the epitympanum. Follow-up at one month revealed no other problems. Histopathology of the specimen was consistent with a giant cell reparative granuloma. ImagesFigure 1Figure 2p91-aFigure 3 PMID:17171108

  17. Annual to sub-annual 3D surface evolution of an Antarctic blue-ice moraine using multi-platform, multi-temporal high resolution topography

    NASA Astrophysics Data System (ADS)

    Westoby, Matthew; Dunning, Stuart; Woodward, John; Hein, Andrew; Marrero, Shasta; Winter, Kate; Sugden, David

    2016-04-01

    High-resolution topographic data products are now routinely used for the geomorphological characterisation of Earth surface landforms and landscapes, whilst the acquisition and differencing of such datasets are swiftly becoming the preferred method for quantifying the transfer of mass through landscapes at the spatial scales of observation at which many processes operate. In this research, we employ 3-D differencing of repeat high-resolution topography to quantify the surface evolution of a 0.3 km2 blue-ice moraine complex in front of Patriot Hills, Antarctica. We used terrestrial laser scanning (TLS) to acquire multiple overlapping 3D datasets of the moraine surface at the beginning and end of the austral summer season in 2012/2013 and during a resurvey campaign in 2014. An additional topographic dataset was acquired at the end of season 1 through the application of a Structure-from-Motion with Multi-View Stereo (SfM-MVS) workflow to a set of aerial photographs acquired during a single unmanned aerial vehicle (UAV) sortie. 3D cloud-to-cloud differencing was undertaken using the M3C2 algorithm. The results of 3D differencing revealed net uplift (median ~0.05 m) and lateral (xy) movement (median 0.02 m) of the moraine crests within season 1. Analysis of results from the longest differencing epoch (start of season 1 to season 2) suggests gradual but persistent surface uplift (median ~0.11 m) and sustained lateral movement (median ~0.05 m). Locally, lowering of a similar magnitude to uplift was observed in inter-moraine troughs and close to the current ice margin. This research demonstrates that it is possible to detect dynamic surface topographic change across glacial moraines over short timescales through the acquisition and differencing of high-resolution topographic datasets. Such data and methods of analysis offer new opportunities to understand glaciological and geomorphological process linkages in remote glacial environments.

  18. Dual immunofluorescence staining of proteoglycans in human temporal bones.

    PubMed

    Markaryan, Adam; Nelson, Erik G; Kohut, Robert I; Hinojosa, Raul

    2011-07-01

    Immunofluorescence staining methods have been developed to study the distribution of macromolecules in archival formalin-fixed celloidin-embedded human temporal bone tissues. The aim of this study was to investigate the feasibility of utilizing this approach to evaluate the codistribution of more than one molecule of interest in a single tissue section. Retrospective study of proteoglycan codistribution in archival human temporal bone tissues. The chondroitin sulfate and keratan sulfate proteoglycans were selected for evaluating this methodology. Human tissues with known proteoglycan staining patterns were studied as controls. Thirty-one formalin-fixed celloidin-embedded archival human temporal bones were evaluated, and the observations in 11 specimens are described. A dual immunofluorescence staining method was developed using primary antibodies of differing isotypes and secondary antibodies labeled with fluorophores having nonoverlapping emission characteristics. The specificity of the dual immunofluorescence technique for chondroitin sulfate and keratan sulfate proteoglycans was demonstrated in control tissues and confirmed through inhibition studies. The normal human tectorial membrane exhibited intense chondroitin sulfate staining. Cochlear and vestibular hair cells exhibited predominantly keratan sulfate staining. Keratan sulfate staining predominated in spiral ganglion cell bodies and fibers. Alterations in the normal distribution pattern of proteoglycans were observed in cases of presbycusis and otosclerosis. The dual immunofluorescence staining methodology can be used to study archival formalin-fixed celloidin-embedded human temporal bone tissues. This technique may be applied to the evaluation of other molecules in archival human temporal bone tissues and lead to improvement in our understanding of the function of these molecules and their role in disease processes. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  19. Multimodal imaging of the human temporal bone: A comparison of CT and optical scanning techniques

    NASA Astrophysics Data System (ADS)

    Voie, Arne H.; Whiting, Bruce; Skinner, Margaret; Neely, J. Gail; Lee, Kenneth; Holden, Tim; Brunsden, Barry

    2003-10-01

    A collaborative effort between Washington University in St. Louis and Spencer Technologies in Seattle, WA has been undertaken to create a multimodal 3D reconstruction of the human cochlea and vestibular system. The goal of this project is to improve the accuracy of in vivo CT reconstructions of implanted cochleae, and to expand the knowledge of high-resolution anatomical detail provided by orthogonal-plane optical sectioning (OPFOS). At WUSL, computed tomography (CT) images of the cochlea are used to determine the position of cochlear implant electrodes relative to target auditory neurons. The cochlear implant position is determined using pre- and post-operative CT scans. The CT volumes are cross-registered to align the semicircular canals and internal auditory canal, which have a unique configuration in 3-D space. The head of a human body donor was scanned with a clinical CT device, after which the temporal bones were removed, fixed in formalin and trimmed prior to scanning with a laboratory Micro CT scanner. Following CT, the temporal bones were sent to the OPFOS Imaging Lab at Spencer Technologies for a further analysis. 3-D reconstructions of CT and OPFOS imaging modalities were compared, and results are presented. [Work supported by NIDCD Grants R44-03623-5 and R01-00581-13.

  20. Post-Traumatic Bilateral Facial Paralysis Associated with Temporal Bone Fracture.

    PubMed

    Habib, Syed Shahid; Al Rouq, Fawzia; Meo, Imran

    2015-10-01

    Bilateral traumatic facial paralysis is a very rare clinical condition. Loss of taste sensation, associated with bilateral traumatic paralysis, is even rarer and has not been well described in the literature. In this report, a 23-year old male, who developed bilateral facial paralysis with loss of taste sensation and hearing impairment, following a motor vehicle accident, is presented. He had initially presented with unconsciousness for about 2 hours after he sustained closed head injury after a motor vehicle accident. Initial Computed Tomography (CT) scans revealed a small epidural hematoma, right temporal bone fracture and air densities around the basal cistern. On the 4th day after trauma, he was noted to have incomplete closure of both eyes and was feeling difficulty with chewing and drooling of saliva. Electrodiagnostic testing confirmed the diagnosis of bilateral facial paralysis-House-Brackmann (HB) grade V. Electroneuronography (ENoG) showed degeneration of 90% nerve fibres bilaterally. The high-resolution CT scans showed bilateral temporal bone fractures. At 3 months of follow-up, the patient had partial recovery of facial nerve function bilaterally and improvement in HB classification to grade III and ENoG of 60% was observed.

  1. Temporal bone characterization and cochlear implant feasibility in the common marmoset (Callithrix jacchus).

    PubMed

    Johnson, Luke A; Della Santina, Charles C; Wang, Xiaoqin

    2012-08-01

    The marmoset (Callithrix jacchus) is a valuable non-human primate model for studying behavioral and neural mechanisms related to vocal communication. It is also well suited for investigating neural mechanisms related to cochlear implants. The purpose of this study was to characterize marmoset temporal bone anatomy and investigate the feasibility of implanting a multi-channel intracochlear electrode into the marmoset scala tympani. Micro computed tomography (microCT) was used to create high-resolution images of marmoset temporal bones. Cochlear fluid spaces, middle ear ossicles, semicircular canals and the surrounding temporal bone were reconstructed in three-dimensional space. Our results show that the marmoset cochlea is ∼16.5 mm in length and has ∼2.8 turns. The cross-sectional area of the scala tympani is greatest (∼0.8 mm(2)) at ∼1.75 mm from the base of the scala, reduces to ∼0.4 mm(2) at 5 mm from the base, and decreases at a constant rate for the remaining length. Interestingly, this length-area profile, when scaled 2.5 times, is similar to the scala tympani of the human cochlea. Given these dimensions, a compatible multi-channel implant electrode was identified. In a cadaveric specimen, this electrode was inserted ¾ turn into the scala tympani through a cochleostomy at ∼1 mm apical to the round window. The depth of the most apical electrode band was ∼8 mm. Our study provides detailed structural anatomy data for the middle and inner ear of the marmoset, and suggests the potential of the marmoset as a new non-human primate model for cochlear implant research.

  2. "Bones of Contention". The donation of temporal bones for dissection after the organ-retention scandals.

    PubMed

    Morris, D P; Benbow, E W; Ramsden, R T

    2001-09-01

    It is essential for the Otologist in training to become familiar with the anatomy of the temporal bone. Generations of trainees have acquired this knowledge, together with basic surgical skills and techniques by dissection of cadaver temporal bones. In recent years, however, the supply of temporal bones for dissection has become a contentious issue in many British hospitals. Media and public attention has recently focused on issues surrounding the retention of human tissues following post-mortem examinations. In response, the Chief Medical Officer, the Royal College of Pathologists in the UK, the Faculty of Pathology of the Royal College of Physicians in Ireland, the British Medical Association, and other bodies have issued new guidelines that are of relevance to the Otolaryngologist. This paper gives details of some of the UK guidelines and where they can be accessed. A copy of the Royal College of Pathologists preferred post-mortem consent form is presented. The authors' experience in Manchester is discussed and details of an information leaflet on the subject of temporal bone donation are given. It is concluded that, with knowledge of the existing guidelines and good communication with other hospital colleagues, as well as families of the deceased, it is still possible legally to obtain temporal bones for dissection.

  3. High-resolution headlamp

    NASA Astrophysics Data System (ADS)

    Gut, Carsten; Cristea, Iulia; Neumann, Cornelius

    2016-04-01

    The following article shall describe how human vision by night can be influenced. At first, front lighting systems that are already available on the market will be described, followed by their analysis with respect to the positive effects on traffic safety. Furthermore, how traffic safety by night can be increased since the introduction of high resolution headlamps shall be discussed.

  4. Temporal bone dissection simulator for training pediatric otolaryngology surgeons

    NASA Astrophysics Data System (ADS)

    Tabrizi, Pooneh R.; Sang, Hongqiang; Talari, Hadi F.; Preciado, Diego; Monfaredi, Reza; Reilly, Brian; Arikatla, Sreekanth; Enquobahrie, Andinet; Cleary, Kevin

    2017-03-01

    Cochlear implantation is the standard of care for infants born with severe hearing loss. Current guidelines approve the surgical placement of implants as early as 12 months of age. Implantation at a younger age poses a greater surgical challenge since the underdeveloped mastoid tip, along with thin calvarial bone, creates less room for surgical navigation and can result in increased surgical risk. We have been developing a temporal bone dissection simulator based on actual clinical cases for training otolaryngology fellows in this delicate procedure. The simulator system is based on pre-procedure CT (Computed Tomography) images from pediatric infant cases (<12 months old) at our hospital. The simulator includes: (1) simulation engine to provide the virtual reality of the temporal bone surgery environment, (2) a newly developed haptic interface for holding the surgical drill, (3) an Oculus Rift to provide a microscopic-like view of the temporal bone surgery, and (4) user interface to interact with the simulator through the Oculus Rift and the haptic device. To evaluate the system, we have collected 10 representative CT data sets and segmented the key structures: cochlea, round window, facial nerve, and ossicles. The simulator will present these key structures to the user and warn the user if needed by continuously calculating the distances between the tip of surgical drill and the key structures.

  5. Osteoradionecrosis of the Temporal Bone Leading to Cerebellar Abscess

    PubMed Central

    2017-01-01

    Squamous cell carcinoma of the temporal bone is a rare and destructive malignancy and represents both diagnostic and therapeutic challenge. The complex regional anatomy of the temporal bone requires equally intricate surgical techniques to adequately resect the tumour mass during surgical excision. Adjuvant radiotherapy is offered to patients with advanced disease and has been showed to confer a survival benefit in carefully selected patients. One feared complication of radiotherapy is osteoradionecrosis and is a major obstacle faced in the treatment of head and neck cancers. The case presented here is a rare example of a patient who was successfully treated for SCC of the temporal with both surgical resection and adjuvant radiotherapy who subsequently developed two major complications: first, osteoradionecrosis of the temporal bone that leads to penetrating osteomyelitis; second, the formation of a large cerebellar abscess that required surgical drainage. This case is a rare example of the complications that are possible following radiotherapy to the head and the close follow-up that is required in patients. PMID:28326215

  6. Osteoradionecrosis of the Temporal Bone Leading to Cerebellar Abscess.

    PubMed

    Layton, Thomas B

    2017-01-01

    Squamous cell carcinoma of the temporal bone is a rare and destructive malignancy and represents both diagnostic and therapeutic challenge. The complex regional anatomy of the temporal bone requires equally intricate surgical techniques to adequately resect the tumour mass during surgical excision. Adjuvant radiotherapy is offered to patients with advanced disease and has been showed to confer a survival benefit in carefully selected patients. One feared complication of radiotherapy is osteoradionecrosis and is a major obstacle faced in the treatment of head and neck cancers. The case presented here is a rare example of a patient who was successfully treated for SCC of the temporal with both surgical resection and adjuvant radiotherapy who subsequently developed two major complications: first, osteoradionecrosis of the temporal bone that leads to penetrating osteomyelitis; second, the formation of a large cerebellar abscess that required surgical drainage. This case is a rare example of the complications that are possible following radiotherapy to the head and the close follow-up that is required in patients.

  7. Rapid decalcification of temporal bones with preservation of ultrastructure.

    PubMed

    Madden, V J; Henson, M M

    1997-09-01

    Decalcification of temporal bones, especially from primates, has routinely required long periods of time and has been a major deterrent to many types of morphological studies. In this investigation, temporal bones from the monkey, Macaca fuscata, were decalcified with ethylene diamine tetraacetic acid (EDTA) in a microwave oven. To isolate effects of microwaves on decalcification, tissue was fixed and embedded using routine methods; only decalcification was carried out in the microwave oven. The procedure is described in detail. Instead of months, decalcification was complete in two working days. Control procedures included decalcification at room temperature and use of a regular oven at a temperature equal to that reached in the microwave. The ultrastructure of cochlear tissue was equal to or better than that obtained with routine decalcification.

  8. High resolution data acquisition

    DOEpatents

    Thornton, G.W.; Fuller, K.R.

    1993-04-06

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock, pulse train, and analog circuitry for generating a triangular wave synchronously with the pulse train (as seen in diagram on patent). The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  9. High resolution data acquisition

    DOEpatents

    Thornton, Glenn W.; Fuller, Kenneth R.

    1993-01-01

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock (38) pulse train (37) and analog circuitry (44) for generating a triangular wave (46) synchronously with the pulse train (37). The triangular wave (46) has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter (18, 32) forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter (26) counts the clock pulse train (37) during the interval to form a gross event interval time. A computer (52) then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  10. Panoramic High Resolution Spectroscopy

    NASA Astrophysics Data System (ADS)

    Freeman, K.; Bland-Hawthorn, J.

    2008-10-01

    Stellar populations in galaxies are vast repositories of fossil information. In recent years it has become possible to consider high resolution spectroscopic surveys of millions of stars. New high resolution multi-object spectrographs on 4-8m class telescopes (HERMES, WFMOS) will allow us for the first time to make large and detailed chemical abundance surveys of stars in the Galactic disk, bulge and halo, and apply the techniques of chemical tagging to recovering the fossil information left over from galaxy assembly. These instruments will have strong synergies with the GAIA astrometric satellite due to launch in 2011. The level of detail made possible by these future facilities will be necessary if we are to fully understand the physical processes involved in galaxy formation.

  11. High resolution data acquisition

    SciTech Connect

    Thornton, G.W.; Fuller, K.R.

    1992-12-31

    A high resolution event interval timing system measures short time intervals such as occur in high energy physics or laser ranging. Timing is provided from a clock pulse train and analog circuitry for generating a triangular wave synchronously with the pulse train. The triangular wave has an amplitude and slope functionally related to the time elapsed during each clock pulse in the train. A converter forms a first digital value of the amplitude and slope of the triangle wave at the start of the event interval and a second digital value of the amplitude and slope of the triangle wave at the end of the event interval. A counter counts the clock pulse train during the interval to form a gross event interval time. A computer then combines the gross event interval time and the first and second digital values to output a high resolution value for the event interval.

  12. High-Resolution Autoradiography

    NASA Technical Reports Server (NTRS)

    Towe, George C; Gomberg, Henry J; Freemen, J W

    1955-01-01

    This investigation was made to adapt wet-process autoradiography to metallurgical samples to obtain high resolution of segregated radioactive elements in microstructures. Results are confined to development of the technique, which was perfected to a resolution of less than 10 microns. The radioactive samples included carbon-14 carburized iron and steel, nickel-63 electroplated samples, a powder product containing nickel-63, and tungsten-185 in N-155 alloy.

  13. Ultra high resolution tomography

    SciTech Connect

    Haddad, W.S.

    1994-11-15

    Recent work and results on ultra high resolution three dimensional imaging with soft x-rays will be presented. This work is aimed at determining microscopic three dimensional structure of biological and material specimens. Three dimensional reconstructed images of a microscopic test object will be presented; the reconstruction has a resolution on the order of 1000 A in all three dimensions. Preliminary work with biological samples will also be shown, and the experimental and numerical methods used will be discussed.

  14. Bilateral congenital cholesteatoma of the temporal bone in Crouzon syndrome.

    PubMed

    Djerić, Dragoslava; Čvorović, Ljiljana; Blažić, Srbislav

    2015-01-01

    Crouzon syndrome is an autosomal dominant genetic disease characterized by bicoronal craniosynostosis, exorbitism with hypertelorism, and maxillary hypoplasia with mandibular prognathism. We present the first reported case of Crouzon syndrome associated with a bilateral con- genital cholesteatoma of the temporal bone and discuss about the potential pathogenesis. Early diagnosis and management are crucial to prevent complications and an otologist should be an integral part of the multidisciplinary team.

  15. High resolution three-dimensional (256 to the 3rd) spatio-temporal measurements of the conserved scalar field in turbulent shear flows

    NASA Astrophysics Data System (ADS)

    Dahm, Werner J. A.; Buch, Kenneth A.

    Results from highly resolved three-dimensional spatio-temporal measurements of the conserved scalar field zeta(x,t) in a turbulent shear flow. Each of these experiments consists of 256 to the 3rd individual point measurements of the local instantaneous conserved scalar value in the flow. The spatial and temporal resolution of these measurements reach beyond the local Kolmogorov scale and resolve the local strain-limited molecular diffusion scale in the flow. The results clearly show molecular mixing occurring in thin strained laminar diffusion layers in a turbulent flow.

  16. Use of Aerial high resolution visible imagery to produce large river bathymetry: a multi temporal and spatial study over the by-passed Upper Rhine

    NASA Astrophysics Data System (ADS)

    Béal, D.; Piégay, H.; Arnaud, F.; Rollet, A.; Schmitt, L.

    2011-12-01

    Aerial high resolution visible imagery allows producing large river bathymetry assuming that water depth is related to water colour (Beer-Bouguer-Lambert law). In this paper we aim at monitoring Rhine River geometry changes for a diachronic study as well as sediment transport after an artificial injection (25.000 m3 restoration operation). For that a consequent data base of ground measurements of river depth is used, built on 3 different sources: (i) differential GPS acquisitions, (ii) sounder data and (iii) lateral profiles realized by experts. Water depth is estimated using a multi linear regression over neo channels built on a principal component analysis over red, green and blue bands and previously cited depth data. The study site is a 12 km long reach of the by-passed section of the Rhine River that draws French and German border. This section has been heavily impacted by engineering works during the last two centuries: channelization since 1842 for navigation purposes and the construction of a 45 km long lateral canal and 4 consecutive hydroelectric power plants of since 1932. Several bathymetric models are produced based on 3 different spatial resolutions (6, 13 and 20 cm) and 5 acquisitions (January, March, April, August and October) since 2008. Objectives are to find the optimal spatial resolution and to characterize seasonal effects. Best performances according to the 13 cm resolution show a 18 cm accuracy when suspended matters impacted less water transparency. Discussions are oriented to the monitoring of the artificial reload after 2 flood events during winter 2010-2011. Bathymetric models produced are also useful to build 2D hydraulic model's mesh.

  17. Spatial and temporal variability of column-integrated CO2: identifying drivers and variations from high-resolution model simulations and OCO-2 observations

    NASA Astrophysics Data System (ADS)

    Chatterjee, A.; Ott, L.; Wennberg, P. O.; Kawa, S. R.; O'Dell, C.; Osterman, G. B.; Wunch, D.

    2015-12-01

    Isolating the drivers and variations in column-averaged dry air mole fraction of carbon dioxide (XCO2) is essential for mining information from space-based remote-sensing observations, such as those available from the Orbiting Carbon Observatory-2 (OCO-2). Contrary to the large number of studies analyzing the variability of surface CO2 concentrations, studies analyzing the spatiotemporal variability of XCO2 are relatively limited. More importantly, these results are either based on a sparse network of ground-based total column observations (i.e., from the Total Column Carbon Observing Network - TCCON) or derived from low-resolution model simulations. In this study, using the high-resolution (~7 km) GEOS-5 model simulated fields and the high-density observations from OCO-2, we investigate how variability in surface fluxes and/or meteorological drivers impact the observed XCO2 variability across a range of scales. The study focuses on ~13:30 LT and is designed to highlight the significant contributors to local and regional scale XCO2 variability from daily to seasonal timescales. In collaboration with the OCO-2 Validation team, the variability information is also being used to identify small geographical areas (<1° or ~100km) where the XCO2 is expected to be relatively constant. These small areas then serve as target regions for examining the potential of external variables (for e.g., surface reflectance, aerosol) to generate biases (variability) in the XCO2 retrievals in those regions. We will also show comparison results of the model-based variability analyses with the variability statistics derived from actual OCO-2 retrievals. This comparison serves as an important consistency check for the simulated fields from the GEOS-5 model. Finally, we will review these results in terms of assessing and quantifying representation errors as well as developing and implementing data thinning/'superobbing' algorithms for OCO-2 retrievals.

  18. Primary Ewing's Sarcoma of the temporal bone in an infant.

    PubMed

    Goudarzipour, Kourosh; Shamsian, Shahin; Alavi, Samin; Nourbakhsh, Kazem; Aghakhani, Roxana; Eydian, Zahra; Arzanian, Mohammad Taghi

    2015-04-01

    Introduction : Ewing's sarcoma is the second most common primary malignant tumor of bone found in children after Osteosarcoma. It accounts for 4-9% of primary malignant bone tumors and it affects bones of the skull or face in only 1-4% of cases. Hence it rarely affects the head and neck. Subject and Method : In this case report, we describe a case of primary Ewing's sarcoma occurring in the temporal bone. The tumor was surgically excised, and the patient underwent chemotherapy for ten months. Results : Neither recurrence nor distant metastasis was noted in these 10 months after surgery but about 18 months after surgery our patient was expired. Conclusion : Although the prognosis of Ewing's sarcoma is generally poor because of early metastasis to the lungs and to other bones, a review of the article suggested that Ewing's sarcoma occurring in the skull can often be successfully managed by intensive therapy with radical excision and chemotherapy. This result was supported by the case reported here.

  19. High-resolution measurements of the spatial and temporal evolution of megagauss magnetic fields created in intense short-pulse laser-plasma interactions

    SciTech Connect

    Chatterjee, Gourab Singh, Prashant Kumar; Adak, Amitava; Lad, Amit D.; Kumar, G. Ravindra

    2014-01-15

    A pump-probe polarimetric technique is demonstrated, which provides a complete, temporally and spatially resolved mapping of the megagauss magnetic fields generated in intense short-pulse laser-plasma interactions. A normally incident time-delayed probe pulse reflected from its critical surface undergoes a change in its ellipticity according to the magneto-optic Cotton-Mouton effect due to the azimuthal nature of the ambient self-generated megagauss magnetic fields. The temporal resolution of the magnetic field mapping is typically of the order of the pulsewidth, limited by the laser intensity contrast, whereas a spatial resolution of a few μm is achieved by this optical technique. High-harmonics of the probe can be employed to penetrate deeper into the plasma to even near-solid densities. The spatial and temporal evolution of the megagauss magnetic fields at the target front as well as at the target rear are presented. The μm-scale resolution of the magnetic field mapping provides valuable information on the filamentary instabilities at the target front, whereas probing the target rear mirrors the highly complex fast electron transport in intense laser-plasma interactions.

  20. Saturn's rings - high resolution

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Voyager 2 obtained this high-resolution picture of Saturn's rings Aug. 22, when the spacecraft was 4 million kilometers (2.5 million miles) away. Evident here are the numerous 'spoke' features, in the B-ring; their very sharp, narrow appearance suggests short formation times. Scientists think electromagnetic forces are responsible in some way for these features, but no detailed theory has been worked out. Pictures such as this and analyses of Voyager 2's spoke movies may reveal more clues about the origins of these complex structures. The Voyager project is managed for NASA by the Jet Propulsion Laboratory, Pasadena, Calif.

  1. The Pitfalls and Important Distances in Temporal Bone HRCT of the Subjects with High Jugular Bulbs - Preliminary Report.

    PubMed

    Inal, Mikail; Muluk, Nuray B; Dağ, Ersel; Arıkan, Osman K; Kara, Simay A

    2015-01-01

    High jugular bulb (HJB) may be detected unilaterally or bilaterally in temporal bone high resolution computerized tomography (HRCT). In this retrospective study, we investigated the pitfalls and important surgical distances in patients with unilateral and bilateral HJB via temporal bone HRCT. In this preliminary report, the study group consisted of 20 adult patients (12 male, 8 female), or 40 ears, all of which underwent temporal bone HRCT. We divided them into groups that consisted of bilateral HJB (14 ears), unilateral HJB (13 ears), and control (No HJB, 13 ears). The anotomical relationships of the sigmoid sinus, jugular bulb, and carotid artery with several landmarks in the temporal bone were studied via temporal bone axial and coronal HRCT. The shortest distances between certain points were measured. These measurements were analyzed in respect to pneumatization. Dehiscence on the jugular bulb (JB) and internal carotid artery (ICA) and the dominance of JB were also evaluated for all of the groups. In the axial sections of the temporal bone HRCTs, the sigmois sinus (SS)-external auditory canal (EAC) distance of the bilateral HJB group (14.00±1.17 mm) was significantly lower than that of the control group (16.46±2.14 mm). The JB-posteromedial points of the umbo on the ear drum (ED) distance of the bilateral HJB (6.28±1.72 mm) and the unilateral HJB groups (7.23±2.00 mm) were significantly lower than that of the control group (11.15±2.30 mm). In the coronal sections of the temporal bone HRCT, the JB-F distance of the bilateral HJB group (5.42±2.10 mm) was significantly lower than that of the control group (8.30±2.28 mm). As the mastoid pneumatisation and mastoid volume increased, the percentage of ICA-dehiscence and the percentage of JB-dehiscence increased. In subjects with well-pneumatised mastoids, the doctors should be aware of the increased risk of ICA-dehiscence and JB-dehiscence. These measurements should be done in greater series to yield more

  2. Pediatric Temporal Bone Fractures: A 10-Year Experience.

    PubMed

    Wexler, Sonya; Poletto, Erica; Chennupati, Sri Kiran

    2016-01-16

    The aim of the study was to compare the traditional and newer temporal bone fracture classification systems and their reliability in predicting serious outcomes of hearing loss and facial nerve (FN) injury. We queried the medical record database for hospital visits from 2002 to 2013 related to the search term temporal. A total of 1144 records were identified, and of these, 46 records with documented temporal bone fractures were reviewed for patient age, etiology and classification of the temporal bone fracture, FN examination, and hearing status. Of these records, radiology images were available for 38 patients and 40 fractures. Thirty-eight patients with accessible radiologic studies, aged 10 months to 16 years, were identified as having 40 temporal bone fractures for which the otolaryngology service was consulted. Twenty fractures (50.0%) were classified as longitudinal, 5 (12.5%) as transverse, and 15 (37.5%) as mixed. Using the otic capsule sparing (OCS)/violating nomenclature, 32 (80.0%) of fractures were classified as OCS, 2 (5.0%) otic capsule violating (OCV), and 6 (15.0%) could not be classified using this system. The otic capsule was involved in 1 (5%) of the longitudinal fractures, none of the transverse fractures, and 1 (6.7%) of the mixed fractures. Sensorineural hearing loss was found in only 2 fractures (5.0%) and conductive hearing loss (CHL) in 6 fractures (15.0%). Two fractures (5.0%) had ipsilateral facial palsy but no visualized fracture through the course of the FN canal. Neither the longitudinal/transverse/mixed nor OCS/OCV classifications were predictors of sensorineural hearing loss (SNHL), CHL, or FN involvement by Fisher exact statistical analysis (for SNHL: P = 0.37 vs 0.16; for CHL: P = 0.71 vs 0.33; for FN: P = 0.62 vs 0.94, respectively). In this large pediatric series, neither classification system of longitudinal/transverse/mixed nor OCS/OCV was predictive of SNHL, CHL, or FN palsy. A more robust database of audiologic results would

  3. High-Resolution X-Ray Techniques as New Tool to Investigate the 3D Vascularization of Engineered-Bone Tissue

    PubMed Central

    Bukreeva, Inna; Fratini, Michela; Campi, Gaetano; Pelliccia, Daniele; Spanò, Raffaele; Tromba, Giuliana; Brun, Francesco; Burghammer, Manfred; Grilli, Marco; Cancedda, Ranieri; Cedola, Alessia; Mastrogiacomo, Maddalena

    2015-01-01

    The understanding of structure–function relationships in normal and pathologic mammalian tissues is at the basis of a tissue engineering (TE) approach for the development of biological substitutes to restore or improve tissue function. In this framework, it is interesting to investigate engineered bone tissue, formed when porous ceramic constructs are loaded with bone marrow stromal cells (BMSC) and implanted in vivo. To monitor the relation between bone formation and vascularization, it is important to achieve a detailed imaging and a quantitative description of the complete three-dimensional vascular network in such constructs. Here, we used synchrotron X-ray phase-contrast micro-tomography to visualize and analyze the three-dimensional micro-vascular networks in bone-engineered constructs, in an ectopic bone formation mouse-model. We compared samples seeded and not seeded with BMSC, as well as samples differently stained or unstained. Thanks to the high quality of the images, we investigated the 3D distribution of both vessels and collagen matrix and we obtained quantitative information for all different samples. We propose our approach as a tool for quantitative studies of angiogenesis in TE and for any pre-clinical investigation where a quantitative analysis of the vascular network is required. PMID:26442248

  4. High-Resolution X-Ray Techniques as New Tool to Investigate the 3D Vascularization of Engineered-Bone Tissue.

    PubMed

    Bukreeva, Inna; Fratini, Michela; Campi, Gaetano; Pelliccia, Daniele; Spanò, Raffaele; Tromba, Giuliana; Brun, Francesco; Burghammer, Manfred; Grilli, Marco; Cancedda, Ranieri; Cedola, Alessia; Mastrogiacomo, Maddalena

    2015-01-01

    The understanding of structure-function relationships in normal and pathologic mammalian tissues is at the basis of a tissue engineering (TE) approach for the development of biological substitutes to restore or improve tissue function. In this framework, it is interesting to investigate engineered bone tissue, formed when porous ceramic constructs are loaded with bone marrow stromal cells (BMSC) and implanted in vivo. To monitor the relation between bone formation and vascularization, it is important to achieve a detailed imaging and a quantitative description of the complete three-dimensional vascular network in such constructs. Here, we used synchrotron X-ray phase-contrast micro-tomography to visualize and analyze the three-dimensional micro-vascular networks in bone-engineered constructs, in an ectopic bone formation mouse-model. We compared samples seeded and not seeded with BMSC, as well as samples differently stained or unstained. Thanks to the high quality of the images, we investigated the 3D distribution of both vessels and collagen matrix and we obtained quantitative information for all different samples. We propose our approach as a tool for quantitative studies of angiogenesis in TE and for any pre-clinical investigation where a quantitative analysis of the vascular network is required.

  5. Linking innovative measurement technologies (ConMon and Dataflow© systems) for high-resolution temporal and spatial dissolved oxygen criteria assessment.

    PubMed

    O'Leary, C A; Perry, E; Bayard, A; Wainger, L; Boynton, W R

    2015-10-01

    One consequence of nutrient-induced eutrophication in shallow estuarine waters is the occurrence of hypoxia and anoxia that has serious impacts on biota, habitats, and biogeochemical cycles of important elements. Because of the important role of dissolved oxygen (DO) on these ecosystem features, a variety of DO criteria have been established as indicators of system condition. However, DO dynamics are complex and vary on time scales ranging from diel to decadal and spatial scales from meters to multiple kilometers. Because of these complexities, determining DO criteria attainment or failure remains difficult. We propose a method for linking two common measurement technologies for shallow water DO criteria assessment using a Chesapeake Bay tributary as a test case. Dataflow© is a spatially intensive (30-60-m collection intervals) system used to map surface water conditions at the whole estuary scale, and ConMon is a high-frequency (15-min collection intervals) fixed station approach. The former technology is effective with spatial descriptions but poor regarding temporal resolution, while the latter provides excellent temporal but very limited spatial resolution. Our methodology for combining the strengths of these measurement technologies involved a sequence of steps. First, a statistical model of surface water DO dynamics, based on temporally intense ConMon data, was developed. The results of this model were used to calculate daily DO minimum concentrations. Second, this model was then inserted into Dataflow©-generated spatial maps of DO conditions and used to adjust measured DO concentrations to daily minimum concentrations. This information was used to assess DO criteria compliance at the full tributary scale. Model results indicated that it is vital to consider the short-term time scale DO criteria across both space and time concurrently. Large fluctuations in DO occurred within a 24-h time period, and DO dynamics varied across the length and width of the

  6. Interactive Web-based learning module on CT of the temporal bone: anatomy and pathology.

    PubMed

    Phillips, Grace S; LoGerfo, Sung E; Richardson, Michael L; Anzai, Yoshimi

    2012-01-01

    An interactive Web-based learning module on the temporal bone has been developed. It shows normal temporal bone anatomy in four imaging planes: axial, coronal, and parallel and perpendicular to the long axis of the petrous bone. After reviewing the normal anatomy, users should be able to identify key imaging features of pathologic conditions of the temporal bone. Children with congenital abnormalities of the temporal bone may present with conductive or sensorineural hearing loss or both and may have a genetic syndrome. Acute otitis media is the most common infection of the temporal bone and is most prevalent among children. Although imaging is unnecessary in uncomplicated otitis media, it is important for evaluation of infectious complications. Classically, temporal bone fractures were described as longitudinal or transverse with respect to the long axis of the petrous bone. However, it is increasingly recognized that many fractures have both longitudinal and transverse components. Patients with temporal bone fractures may have conductive or sensorineural hearing loss in addition to other complications. The most common tumor of the temporal bone at the cerebellopontine angle is the vestibular schwannoma. Paraganglioma is the second most common tumor of the temporal bone and the most common tumor of the middle ear. Supplemental material available at http://uwmsk.org/temporalbone/atlas.html. RSNA, 2012

  7. Using high-resolution soil moisture modelling to assess the uncertainty of microwave remotely sensed soil moisture products at the correct spatial and temporal support

    NASA Astrophysics Data System (ADS)

    Wanders, N.; Karssenberg, D.; Bierkens, M. F. P.; Van Dam, J. C.; De Jong, S. M.

    2012-04-01

    Soil moisture is a key variable in the hydrological cycle and important in hydrological modelling. When assimilating soil moisture into flood forecasting models, the improvement of forecasting skills depends on the ability to accurately estimate the spatial and temporal patterns of soil moisture content throughout the river basin. Space-borne remote sensing may provide this information with a high temporal and spatial resolution and with a global coverage. Currently three microwave soil moisture products are available: AMSR-E, ASCAT and SMOS. The quality of these satellite-based products is often assessed by comparing them with in-situ observations of soil moisture. This comparison is however hampered by the difference in spatial and temporal support (i.e., resolution, scale), because the spatial resolution of microwave satellites is rather low compared to in-situ field measurements. Thus, the aim of this study is to derive a method to assess the uncertainty of microwave satellite soil moisture products at the correct spatial support. To overcome the difference in support size between in-situ soil moisture observations and remote sensed soil moisture, we used a stochastic, distributed unsaturated zone model (SWAP, van Dam (2000)) that is upscaled to the support of different satellite products. A detailed assessment of the SWAP model uncertainty is included to ensure that the uncertainty in satellite soil moisture is not overestimated due to an underestimation of the model uncertainty. We simulated unsaturated water flow up to a depth of 1.5m with a vertical resolution of 1 to 10 cm and on a horizontal grid of 1 km2 for the period Jan 2010 - Jun 2011. The SWAP model was first calibrated and validated on in-situ data of the REMEDHUS soil moisture network (Spain). Next, to evaluate the satellite products, the model was run for areas in the proximity of 79 meteorological stations in Spain, where model results were aggregated to the correct support of the satellite

  8. Analysing and Quantifying Vegetation Responses to Rainfall with High Resolution Spatio-Temporal Time Series Data for Different Ecosystems and Ecotones in Queensland

    NASA Astrophysics Data System (ADS)

    Schmidt, M.; Udelhoven, T.

    2012-07-01

    Vegetation responses and ecosystem function are spatially variable and influenced by climate variability. The Spatial and Temporal Adaptive Reflectance Fusion Model (STARFM) was used to combine MODIS (Moderate Resolution Imaging Spectrometer) and Landsat TM/ETM+ (Thematic Mapper/ Enhanced Thematic Mapper plus) imagery for an 8 year dataset (2000-2007) at 30m spatial resolution with 8 day intervals. This dataset allows for a functional analysis of ecosystem responses, suitable for heterogeneous landscapes. Derived vegetation index information in form of the NDVI (Normalised Difference Vegetation Index) was used to investigate the relationship between vegetation responses and gridded rainfall data for regional ecosystems. A hierarchical decomposition of the time series has been carried out in which relationships among the time-series were individually assessed for deterministic time-series components (trend component and seasonality) as well as for the stochastic seasonal anomalies. While no common long-term trends in NDVI and rainfall data in the time period considered exist, there is however, a strong concurrence in the seasonally of NDVI and rainfall data. This component accounts for the majority of variability in the time-series. On the level of seasonal anomalies, these relationships are more subtle. The statistical analysis required, among others, the removal of temporal autocorrelation for an unbiased assessment of significance. Significant lagged correlations between rainfall and NDVI were found in complex Queensland savannah vegetation communities. For grasslands and open woodlands, significant relationships with lag times between 8 and 16 days were found. For denser, evergreen vegetation communities greater lag times of up to 2.5 months were found. The derived distributed lag models may be used for short-term NDVI and biomass predictions on the spatial resolution scale of Landsat (30m).

  9. Aneurysmal Bone Cyst of the Temporal Bone Presenting with Headache and Partial Facial Palsy

    PubMed Central

    Kletke, Stephanie N.; Popovic, Snezana; Algird, Almunder; Alobaid, Abdullah; Reddy, Kesava K. V.

    2015-01-01

    Background Aneurysmal bone cysts (ABCs) are benign bony lesions that rarely affect the skull base. Very few cases of temporal bone ABCs have been reported. We describe the first case of a temporal bone ABC that was thought to be consistent with a meningioma based on preoperative magnetic resonance imaging (MRI) findings. Clinical Presentation An otherwise healthy 23-year-old woman presented with a pulsatile noise in her left ear and a 4-week history of throbbing headache with nausea. There was no associated emesis, visual or auditory changes, or other neurologic features. Neurologic examination revealed a left lower motor neuron facial paresis. Computed tomography and MRI studies demonstrated a large lesion in the left middle cranial fossa skull base with erosion of the petrous temporal bone. Based on the presence of a “dural tail” on preoperative contrast-enhanced T1-weighted imaging, the lesion was interpreted to likely be consistent with a meningioma. An orbitozygomatic approach was utilized for surgical excision. Histopathologic evaluation was consistent with an ABC. Conclusion Postoperatively the patient had improvement in the lower motor neuron facial paresis. It is important to consider ABC in the differential diagnosis of intracranial lesions accompanied by the dural tail sign on MRI. PMID:26251800

  10. High resolution ultrasonic densitometer

    SciTech Connect

    Dress, W.B.

    1983-01-01

    The velocity of torsional stress pulses in an ultrasonic waveguide of non-circular cross section is affected by the temperature and density of the surrounding medium. Measurement of the transit times of acoustic echoes from the ends of a sensor section are interpreted as level, density, and temperature of the fluid environment surrounding that section. This paper examines methods of making these measurements to obtain high resolution, temperature-corrected absolute and relative density and level determinations of the fluid. Possible applications include on-line process monitoring, a hand-held density probe for battery charge state indication, and precise inventory control for such diverse fluids as uranium salt solutions in accountability storage and gasoline in service station storage tanks.

  11. High resolution hypernuclear spectroscopy

    SciTech Connect

    F. Garibaldi

    2005-02-01

    Hypernuclear spectroscopy provides fundamental information for understanding the effective ?-Nucleon interaction. Jefferson Laboratory experiment E94-107 was designed to perform high resolution hypernuclear spectroscopy by electroproduction of strangeness in four 1p-shell nuclei: 12C, 9Be, 16O, and 7Li. The first part of the experiment on 12C and 9Be has been performed in January and April-May 2004 in Hall A at Jefferson Lab. Significant modifications were made to the standard Hall A apparatus for this challenging experiment: two septum magnets and a RICH detector have been added to get reasonable counting rates and excellent particle identification, as required for the experiment. A description of the apparatus and the preliminary analysis results are presented here.

  12. Mixed reality temporal bone surgical dissector: mechanical design.

    PubMed

    Hochman, Jordan Brent; Sepehri, Nariman; Rampersad, Vivek; Kraut, Jay; Khazraee, Milad; Pisa, Justyn; Unger, Bertram

    2014-08-08

    The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations. Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue. Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill's passage between real and virtual components of the model. No issues with registration at model boundaries were encountered. These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone simulator.

  13. Mixed reality temporal bone surgical dissector: mechanical design

    PubMed Central

    2014-01-01

    Objective The Development of a Novel Mixed Reality (MR) Simulation. An evolving training environment emphasizes the importance of simulation. Current haptic temporal bone simulators have difficulty representing realistic contact forces and while 3D printed models convincingly represent vibrational properties of bone, they cannot reproduce soft tissue. This paper introduces a mixed reality model, where the effective elements of both simulations are combined; haptic rendering of soft tissue directly interacts with a printed bone model. This paper addresses one aspect in a series of challenges, specifically the mechanical merger of a haptic device with an otic drill. This further necessitates gravity cancelation of the work assembly gripper mechanism. In this system, the haptic end-effector is replaced by a high-speed drill and the virtual contact forces need to be repositioned to the drill tip from the mid wand. Previous publications detail generation of both the requisite printed and haptic simulations. Method Custom software was developed to reposition the haptic interaction point to the drill tip. A custom fitting, to hold the otic drill, was developed and its weight was offset using the haptic device. The robustness of the system to disturbances and its stable performance during drilling were tested. The experiments were performed on a mixed reality model consisting of two drillable rapid-prototyped layers separated by a free-space. Within the free-space, a linear virtual force model is applied to simulate drill contact with soft tissue. Results Testing illustrated the effectiveness of gravity cancellation. Additionally, the system exhibited excellent performance given random inputs and during the drill’s passage between real and virtual components of the model. No issues with registration at model boundaries were encountered. Conclusion These tests provide a proof of concept for the initial stages in the development of a novel mixed-reality temporal bone

  14. Temporal bone rhabdomyosarcoma presenting as acute peripheral facial nerve paralysis.

    PubMed

    Reid, Samuel R; Hetzel, Thomas; Losek, Joseph

    2006-10-01

    Facial palsy is not an uncommon presentation to an emergency department. Whereas most patients will ultimately receive a diagnosis of Bell palsy (idiopathic peripheral seventh cranial nerve palsy), a subset will have an identifiable cause for their facial paralysis. Children are more likely to have an identifiable cause than are adults. We present a case in which a child presented with acute peripheral facial nerve palsy and was found to have temporal bone rhabdomyosarcoma. The key clinical finding was the presence of both 7th and 12th cranial nerve palsy.

  15. Sport Injuries of the Ear and Temporal Bone.

    PubMed

    Osetinsky, L Mariel; Hamilton, Grant S; Carlson, Matthew L

    2017-04-01

    In cases of head trauma, the ear should be evaluated in all of its components. A good understanding of otologic and skull base anatomy enables a thorough trauma assessment of this complex anatomic region. Auricular laceration, abrasion, avulsion, hematoma, frostbite, otitis externa, exostosis, tympanic membrane perforation, ossicular discontinuity, perilymphatic fistula, labyrinthine concussion, temporal bone fracture, facial nerve paresis, and sensorineural hearing loss are a few of the more common otologic injuries seen in active patients. Prevention of otologic trauma by wearing protective equipment during activity is the best way of maintaining the long-term health of the ear and audiovestibular function. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Inferring runoff generation processes through high resolution spatial and temporal UV-Vis absorbance measurements in a mountainous headwater catchment in Southern Ecuador

    NASA Astrophysics Data System (ADS)

    Windhorst, David; Schob, Sarah; Zang, Carina; Crespo, Patricio; Breuer, Lutz

    2015-04-01

    The alpine grassland páramo - typically occurring in the headwater catchments of the Andes - plays an important role in flow regulation, hydropower generation and local water supply. However, hydrological and hydro-biogeochemical processes in the páramo and their potential reactions to climate and land use change are largely unknown. Therefore, we used a UV-Vis absorbance spectrometer to investigate fluxes of biochemical oxygen demand (BOD), chemical oxygen demand (COD), turbidity and nitrate (NO3-N) in a small headwater catchment (91.31 km²) in the páramo in south Ecuador on a 5 min temporal and 100 m spatial resolution to gain first insights in its hydrological functioning. Spatial sampling was realized during three snapshot sampling campaigns along the 14.2 km long stream between October 2013 and January 2014, while temporal sampling took place at a permanent sampling site within the catchment between February and June 2014. To identify the runoff generation processes the spatial patterns have been associated with local site specific (e.g. fish ponds) and sub-catchment wide (e.g. land use) characteristics. Storm flow events within the time series allowed to further study temporal changes and rotational patterns of concentration-discharge relations (hysteresis). In total, 35 events were identified to be suitable for analyzing hysteresis effects of BOD, COD, and turbidity. Nitrate concentrations could be studied for 20 events. Regardless of the flow conditions nitrate leaching increased with a growing share of non-native pine forests or pastures in the study area. During low flow conditions, the high water holding capacity of the upstream páramo areas ensured a continuous supply of BOD to the stream. Pasture and pine forest sites, mostly occurring in the downstream section of the stream, contributed to BOD only during discharge events. Contradicting the expectations the trout farms along the lower part of the streams had a relatively closed nutrient cycle and

  17. Monitoring of the Spatial Distribution and Temporal Dynamics of the Green Vegetation Fraction of Croplands in Southwest Germany Using High-Resolution RapidEye Satellite Images

    NASA Astrophysics Data System (ADS)

    Imukova, Kristina; Ingwersen, Joachim; Streck, Thilo

    2014-05-01

    The green vegetation fraction (GVF) is a key input variable to the evapotranspiration scheme applied in the widely used NOAH land surface model (LSM). In standard applications of the NOAH LSM, the GVF is taken from a global map with a 15 km×15 km resolution. The central objective of the present study was (a) to derive gridded GVF data in a high spatial and temporal resolution from RapidEye images for a region in Southwest Germany, and (b) to improve the representation of the GVF dynamics of croplands in the NOAH LSM for a better simulation of water and energy exchange between land surface and atmosphere. For the region under study we obtained monthly RapidEye satellite images with a resolution 5 m×5 m by the German Aerospace Center (DLR). The images hold five spectral bands: blue, green, red, red-edge and near infrared (NIR). The GVF dynamics were determined based on the Normalized Difference Vegetation Index (NDVI) calculated from the red and near-infrared bands of the satellite images. The satellite GVF data were calibrated and validated against ground truth measurements. Digital colour photographs above the canopy were taken with a boom-mounted digital camera at fifteen permanently marked plots (1 m×1 m). Crops under study were winter wheat, winter rape and silage maize. The GVF was computed based on the red and the green band of the photographs according to Rundquist's method (2002). Based on the obtained calibration scheme GVF maps were derived in a monthly resolution for the region. Our results confirm a linear relationship between GVF and NDVI and demonstrate that it is possible to determine the GVF of croplands from RapidEye images based on a simple two end-member mixing model. Our data highlight the high variability of the GVF in time and space. At the field scale, the GVF was normally distributed with a coefficient of variation of about 32%. Variability was mainly caused by soil heterogeneities and management differences. At the regional scale the GVF

  18. 10 Yr Spatial and Temporal Trends of PM2.5 Concentrations in the Southeastern US Estimated Using High-resolution Satellite Data

    NASA Technical Reports Server (NTRS)

    Hu, X.; Waller, L. A.; Lyapustin, A.; Wang, Y.; Liu, Y.

    2013-01-01

    Long-term PM2.5 exposure has been reported to be associated with various adverse health outcomes. However, most ground monitors are located in urban areas, leading to a potentially biased representation of the true regional PM2.5 levels. To facilitate epidemiological studies, accurate estimates of spatiotemporally continuous distribution of PM2.5 concentrations are essential. Satellite-retrieved aerosol optical depth (AOD) has been widely used for PM2.5 concentration estimation due to its comprehensive spatial coverage. Nevertheless, an inherent disadvantage of current AOD products is their coarse spatial resolutions. For instance, the spatial resolutions of the Moderate Resolution Imaging Spectroradiometer (MODIS) and the Multiangle Imaging SpectroRadiometer (MISR) are 10 km and 17.6 km, respectively. In this paper, a new AOD product with 1 km spatial resolution retrieved by the multi-angle implementation of atmospheric correction (MAIAC) algorithm was used. A two-stage model was developed to account for both spatial and temporal variability in the PM2.5-AOD relationship by incorporating the MAIAC AOD, meteorological fields, and land use variables as predictors. Our study area is in the southeastern US, centered at the Atlanta Metro area, and data from 2001 to 2010 were collected from various sources. The model was fitted for each year individually, and we obtained model fitting R2 ranging from 0.71 to 0.85, MPE from 1.73 to 2.50 g m3, and RMSPE from 2.75 to 4.10 g m3. In addition, we found cross validation R2 ranging from 0.62 to 0.78, MPE from 2.00 to 3.01 g m3, and RMSPE from 3.12 to 5.00 g m3, indicating a good agreement between the estimated and observed values. Spatial trends show that high PM2.5 levels occurred in urban areas and along major highways, while low concentrations appeared in rural or mountainous areas. A time series analysis was conducted to examine temporal trends of PM2.5 concentrations in the study area from 2001 to 2010. The results showed

  19. Simultaneous 3D segmentation of three bone compartments on high resolution knee MR images from osteoarthritis initiative (OAI) using graph cuts

    NASA Astrophysics Data System (ADS)

    Shim, Hackjoon; Kwoh, C. Kent; Yun, Il Dong; Lee, Sang Uk; Bae, Kyongtae

    2009-02-01

    Osteoarthritis (OA) is associated with degradation of cartilage and related changes in the underlying bone. Quantitative measurement of those changes from MR images is an important biomarker to study the progression of OA and it requires a reliable segmentation of knee bone and cartilage. As the most popular method, manual segmentation of knee joint structures by boundary delineation is highly laborious and subject to user-variation. To overcome these difficulties, we have developed a semi-automated method for segmentation of knee bones, which consisted of two steps: placement of seeds and computation of segmentation. In the first step, seeds were placed by the user on a number of slices and then were propagated automatically to neighboring images. The seed placement could be performed on any of sagittal, coronal, and axial planes. The second step, computation of segmentation, was based on a graph-cuts algorithm where the optimal segmentation is the one that minimizes a cost function, which integrated the seeds specified by the user and both the regional and boundary properties of the regions to be segmented. The algorithm also allows simultaneous segmentation of three compartments of the knee bone (femur, tibia, patella). Our method was tested on the knee MR images of six subjects from the osteoarthritis initiative (OAI). The segmentation processing time (mean+/-SD) was (22+/-4)min, which is much shorter than that by the manual boundary delineation method (typically several hours). With this improved efficiency, our segmentation method will facilitate the quantitative morphologic analysis of changes in knee bones associated with osteoarthritis.

  20. Towards a Methodology for Estimating Surface Pollutant Mixing Ratios from High Spatial and Temporal Resolution Retrievals, and its Applicability to High-Resolution Space Based Observations

    NASA Astrophysics Data System (ADS)

    Knepp, T.; Pippin, M.; Crawford, J.; Szykman, J.; Long, R.; Neil, D.; Fishman, J.

    2012-11-01

    A ground-based sun-tracking spectrometer system (Pandora) is used to retrieve high time and spatial resolution total-column nitrogen dioxide. These column observations are compared with data from a surface NOx instrument that employs a photolytic converter. The column data are inverted (via the EDAS-40 model) to yield surface mole fractions (i.e.ppb) that have typically high coefficients of correlation (e.g. R = 0.80) with surface data. Translating these column observations into boundary-layer mole fractions provides a direct NO2 data set that can significantly improve the understanding of emission, chemical transportation, effectiveness of control strategies, and predictive capabilities. Preliminary results regarding the relation of surface and column NO2 were presented. Total-column NO2 was recorded using a Pandora sun-tracking spectrometer system [1]. The Pandora instrument provides high-temporal resolution data, with a retrieval done every ~90s under clear-sky conditions. Surface NO2 was recorded using a Teledyne API 200EU with a photolytic converter.

  1. High-Resolution Analyses of Human Leukocyte Antigens Allele and Haplotype Frequencies Based on 169,995 Volunteers from the China Bone Marrow Donor Registry Program

    PubMed Central

    Zhou, Xiao-Yang; Zhu, Fa-Ming; Li, Jian-Ping; Mao, Wei; Zhang, De-Mei; Liu, Meng-Li; Hei, Ai-Lian; Dai, Da-Peng; Jiang, Ping; Shan, Xiao-Yan; Zhang, Bo-Wei; Zhu, Chuan-Fu; Shen, Jie; Deng, Zhi-Hui; Wang, Zheng-Lei; Yu, Wei-Jian; Chen, Qiang; Qiao, Yan-Hui; Zhu, Xiang-Ming; Lv, Rong; Li, Guo-Ying; Li, Guo-Liang; Li, Heng-Cong; Zhang, Xu; Pei, Bin; Jiao, Li-Xin; Shen, Gang; Liu, Ying; Feng, Zhi-Hui; Su, Yu-Ping; Xu, Zhao-Xia; Di, Wen-Ying; Jiang, Yao-Qin; Fu, Hong-Lei; Liu, Xiang-Jun; Liu, Xiang; Zhou, Mei-Zhen; Du, Dan; Liu, Qi; Han, Ying; Zhang, Zhi-Xin; Cai, Jian-Ping

    2015-01-01

    Allogeneic hematopoietic stem cell transplantation is a widely used and effective therapy for hematopoietic malignant diseases and numerous other disorders. High-resolution human leukocyte antigen (HLA) haplotype frequency distributions not only facilitate individual donor searches but also determine the probability with which a particular patient can find HLA-matched donors in a registry. The frequencies of the HLA-A, -B, -C, -DRB1, and -DQB1 alleles and haplotypes were estimated among 169,995 Chinese volunteers using the sequencing-based typing (SBT) method. Totals of 191 HLA-A, 244 HLA-B, 146 HLA-C, 143 HLA-DRB1 and 47 HLA-DQB1 alleles were observed, which accounted for 6.98%, 7.06%, 6.46%, 9.11% and 7.91%, respectively, of the alleles in each locus in the world (IMGT 3.16 Release, Apr. 2014). Among the 100 most common haplotypes from the 169,995 individuals, nine distinct haplotypes displayed significant regionally specific distributions. Among these, three were predominant in the South China region (i.e., the 20th, 31st, and 81sthaplotypes), another three were predominant in the Southwest China region (i.e., the 68th, 79th, and 95th haplotypes), one was predominant in the South and Southwest China regions (the 18th haplotype), one was relatively common in the Northeast and North China regions (the 94th haplotype), and one was common in the Northeast, North and Northwest China (the 40th haplotype). In conclusion, this is the first to analyze high-resolution HLA diversities across the entire country of China, based on a detailed and complete data set that covered 31 provinces, autonomous regions, and municipalities. Specifically, we also evaluated the HLA matching probabilities within and between geographic regions and analyzed the regional differences in the HLA diversities in China. We believe that the data presented in this study might be useful for unrelated HLA-matched donor searches, donor registry planning, population genetic studies, and anthropogenesis

  2. Inter- and intra-observer agreement of high-resolution ultrasonography and power Doppler in assessment of joint inflammation and bone erosions in patients with rheumatoid arthritis.

    PubMed

    Chávez-López, Mario Alfredo; Hernández-Díaz, Cristina; Moya, Carlos; Pineda, Carlos; Ventura-Ríos, Lucio; Möller, Ingrid; Naredo, Esperanza; Espinosa, Rolando; Peña, Angélica; Rosas-Cabral, Alejandro; Filippucci, Emilio

    2013-01-01

    To assess the inter- and intra-observer reproducibility of musculoskeletal ultrasonography among rheumatologist in detecting inflammatory and morphostructural changes in small joints of the hands in patients with rheumatoid arthritis (RA). Five members of the "Escuela de Ecografía del Colegio Mexicano de Reumatología" tested their inter- and intra-observer reliabilities in the assessment of basic sonographic findings of joint inflammation and bone erosion. Their results were compared to those obtained by a group of international experts from European League Against Rheumatism. A clinical rheumatologist evaluated eight RA patients. Five Siemens Acuson Antares ultrasound machines (7-13 MHz linear probes) were used. The OMERACT preliminary definitions of joint effusion, synovial hypertrophy, bone erosions and tenosynovitis were adopted. Inter-observer and intra-observer agreement was calculated by overall agreement and kappa statistics. Mean kappa value for joint effusion was good, 0.654 (85%); synovial hypertrophy, 0.550 (77.2%); power Doppler signal, 0.550 (82.5%); bone erosions, 0.549 (81%); and tenosynovitis, 0.500 (91.5%). Mean and overall intra-observer agreement for semiquantitative score was good for joint effusion, 0.630 (77.2%) and bone erosions, 0.605 (56.25%); and moderate to synovial hypertrophy, 0.476 (65%) and power Doppler signal, 0.471 (80%). Mean kappa value for joint effusion was 0.381 (95%), synovial hypertrophy, 0.447 (72%); power Doppler signal, 0.496 (81%); bone erosions, 0.294 (81%); and tenosynovitis, 0.030 (66%). Mean and overall inter-observer agreement for semiquantitative score was poor for joint effusion, 0.325 (57%) and bone erosions, 0.360 (43%); and moderate to synovial hypertrophy, 0.431 (55%) and power Doppler signal, 0.496 (81%). Intra-observer variability reached the highest levels of agreement. Factors related to the experience of the rheumatologist, the time spent in each examination and knowledge of the software ultrasound

  3. Pediatric all-terrain vehicle related temporal bone fractures.

    PubMed

    Anfuso, Anthony; Weinberger, Paul M; McKinnon, Brian J

    2012-02-01

    To determine the prevalence of helmet use in children involved in all-terrain vehicles (ATV) accidents. Retrospective chart review. Tertiary Academic Medical Center. Retrospective review was performed using the trauma registry of an academic tertiary medical center identifying ATV injured patients under 13 years of age between 2003-2008. Data regarding age, gender, ethnicity, driver/passenger status, helmet status, length of hospital stay, Glascow Coma Scale, Injury Severity Score, Abbreviated Injury Score, and presence of temporal bone fracture were analyzed. Seventy-four ATV injured pediatric subjects were identified. Average age was 8.6 years, 62% male, 38 were drivers, 32 were passengers. Helmet use data were available on 47 (64%) subjects, of these 9 (19%) wore helmets, and 38 (81%) were not wearing helmets. There was no observed statistical difference between helmeted and unhelmeted riders when comparing age, gender, ethnicity, driver/passenger status, length of hospital stay, Glascow Coma Scale (GCS), Injury Severity Score, Abbreviated Injury Score, or presence of temporal bone fracture. This review found that documented helmet use in pediatric ATV injuries to be profoundly low (19%). Within our cohort no protective benefit from helmet use was identified, suggesting the inherent and potentially unalterable dangers of pediatric ATV recreation. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  4. Ossicular Bone Damage and Hearing Loss in Rheumatoid Arthritis: A Correlated Functional and High Resolution Morphometric Study in Collagen-Induced Arthritic Mice

    PubMed Central

    Barbe, Mary F.

    2016-01-01

    Globally, a body of comparative case-control studies suggests that rheumatoid arthritis (RA) patients are more prone to developing hearing loss (HL). However, experimental evidence that supports this hypothesis is still lacking because the human auditory organ is not readily accessible. The aim of this study was to determine the association between bone damage to the ossicles of the middle ear and HL, using a widely accepted murine model of collagen-induced arthritis (RA mice). Diarthrodial joints in the middle ear were examined with microcomputer tomography (microCT), and hearing function was assessed by auditory brainstem response (ABR). RA mice exhibited significantly decreased hearing sensitivity compared to age-matched controls. Additionally, a significant narrowing of the incudostapedial joint space and an increase in the porosity of the stapes were observed. The absolute latencies of all ABR waves were prolonged, but mean interpeak latencies were not statistically different. The observed bone defects in the middle ear that were accompanied by changes in ABR responses were consistent with conductive HL. This combination suggests that conductive impairment is at least part of the etiology of RA-induced HL in a murine model. Whether the inner ear sustains bone erosion or other pathology, and whether the cochlear nerve sustains pathology await subsequent studies. Considering the fact that certain anti-inflammatories are ototoxic in high doses, monitoring RA patients’ auditory function is advisable as part of the effort to ensure their well-being. PMID:27690307

  5. High-resolution mapping of a novel rat blood pressure locus on chromosome 9 to a region containing the Spp2 gene and colocalization of a QTL for bone mass

    PubMed Central

    Nie, Ying; Kumarasamy, Sivarajan; Waghulde, Harshal; Cheng, Xi; Mell, Blair; Czernik, Piotr J.; Lecka-Czernik, Beata

    2016-01-01

    Through linkage analysis of the Dahl salt-sensitive (S) rat and the spontaneously hypertensive rat (SHR), a blood pressure (BP) quantitative trait locus (QTL) was previously located on rat chromosome 9. Subsequent substitution mapping studies of this QTL revealed multiple BP QTLs within the originally identified logarithm of odds plot by linkage analysis. The focus of this study was on a 14.39 Mb region, the distal portion of which remained unmapped in our previous studies. High-resolution substitution mapping for a BP QTL in the setting of a high-salt diet indicated that an SHR-derived congenic segment of 787.9 kb containing the gene secreted phosphoprotein-2 (Spp2) lowered BP and urinary protein excretion. A nonsynonymous G/T polymorphism in the Spp2 gene was detected between the S and S.SHR congenic rats. A survey of 45 strains showed that the T allele was rare, being detected only in some substrains of SHR and WKY. Protein modeling prediction through SWISSPROT indicated that the predicted protein product of this variant was significantly altered. Importantly, in addition to improved cardiovascular and renal function, high salt-fed congenic animals carrying the SHR T variant of Spp2 had significantly lower bone mass and altered bone microarchitecture. Total bone volume and volume of trabecular bone, cortical thickness, and degree of mineralization of cortical bone were all significantly reduced in congenic rats. Our study points to opposing effects of a congenic segment containing the prioritized candidate gene Spp2 on BP and bone mass. PMID:27113531

  6. High Resolution Doppler Imager

    NASA Technical Reports Server (NTRS)

    Hays, Paul B.

    1999-01-01

    This report summarizes the accomplishments of the High Resolution Doppler Imager (HRDI) on UARS spacecraft during the period 4/l/96 - 3/31/99. During this period, HRDI operation, data processing, and data analysis continued, and there was a high level of vitality in the HRDI project. The HRDI has been collecting data from the stratosphere, mesosphere, and lower thermosphere since instrument activation on October 1, 1991. The HRDI team has stressed three areas since operations commenced: 1) operation of the instrument in a manner which maximizes the quality and versatility of the collected data; 2) algorithm development and validation to produce a high-quality data product; and 3) scientific studies, primarily of the dynamics of the middle atmosphere. There has been no significant degradation in the HRDI instrument since operations began nearly 8 years ago. HRDI operations are fairly routine, although we have continued to look for ways to improve the quality of the scientific product, either by improving existing modes, or by designing new ones. The HRDI instrument has been programmed to collect data for new scientific studies, such as measurements of fluorescence from plants, measuring cloud top heights, and lower atmosphere H2O.

  7. Primary aneurysmal bone cyst of the petrous temporal bone: A case report and review of literature

    PubMed Central

    Sharma, Mayur; Velho, Vernon; Kharosekar, Hrushikesh

    2016-01-01

    Aneurysmal bone cyst (ABC) arising in the petrous portion of the temporal bone is a rare entity with only five such reported cases in the literature. We report the case of a 28-year-old man who presented with a tender swelling in the right preauricular region with right ear discharge and conductive hearing loss of 4 years' duration. Computed tomography and Magnetic Resonance imaging showed a destructive lesion in the right petrous bone with cavitation consistent with the diagnosis of ABC. Gross total resection of the lesion was achieved and diagnosis was confirmed histologically. The patient had no recurrence at 12 months of follow-up. This report presents the unusual location of an uncommon bony tumor with a review of its clinical, radiological, and histopathological features as well as the treatment modalities available. PMID:27695554

  8. High resolution microscopic survey of third metacarpal articular calcified cartilage and subchondral bone in the juvenile horse: possible implications in chondro-osseous disease.

    PubMed

    Boyde, Alan; Firth, Elwyn C

    2008-06-01

    The aim was to survey articular calcified cartilage (ACC) and subchondral bone in the palmar and dorsal regions of the condyles of the third metacarpal bone (Mc3) of young horses with minimal or no signs of musculo-skeletal abnormality. Back-scattered electron scanning electron microscopy (BSE SEM) was conducted on polymethyl methacrylate-embedded mediolateral slices and macerated wedges of the right distal Mc3 from seven each of trained and untrained 2-year-old Thoroughbred horses. Furrows or grooves visible to the naked eye in the mineralizing front (MF) of ACC are the commonest "lesion" and are most common in the palmar portions of the medial and lateral condylar grooves. Cracks running predominantly in the parasagittal plane that infill with hypercalcified matrix are found in the same domain. Common to all these defects are deficiencies or absence of the ACC MF. Other anomalies include local excrescences or depressed areas of the MF. More important condylar lesions show displaced fragmented hypermineralized ACC with underlying excess resorption in the bone domain, leaving a thin ACC layer with cavernous space beneath it. The fragments may dislodge and displace to the joint space. Obvious although small lesions are present in horses that have undertaken little or no training. The nature and sites of the lesions indicate that they are possibly the earliest morphological evidence of changes that may lead to specific joint abnormalities. The lesions appear unlikely to be solely due to functional traumatic forces, and developmental influences are likely to be important in their initiation.

  9. Improving In Vivo High-Resolution CT Imaging of the Tumour Vasculature in Xenograft Mouse Models through Reduction of Motion and Bone-Streak Artefacts

    PubMed Central

    Kersemans, Veerle; Kannan, Pavitra; Beech, John S.; Bates, Russell; Irving, Benjamin; Gilchrist, Stuart; Allen, Philip D.; Thompson, James; Kinchesh, Paul; Casteleyn, Christophe; Schnabel, Julia; Partridge, Mike; Muschel, Ruth J.; Smart, Sean C.

    2015-01-01

    Introduction Preclinical in vivo CT is commonly used to visualise vessels at a macroscopic scale. However, it is prone to many artefacts which can degrade the quality of CT images significantly. Although some artefacts can be partially corrected for during image processing, they are best avoided during acquisition. Here, a novel imaging cradle and tumour holder was designed to maximise CT resolution. This approach was used to improve preclinical in vivo imaging of the tumour vasculature. Procedures A custom built cradle containing a tumour holder was developed and fix-mounted to the CT system gantry to avoid artefacts arising from scanner vibrations and out-of-field sample positioning. The tumour holder separated the tumour from bones along the axis of rotation of the CT scanner to avoid bone-streaking. It also kept the tumour stationary and insensitive to respiratory motion. System performance was evaluated in terms of tumour immobilisation and reduction of motion and bone artefacts. Pre- and post-contrast CT followed by sequential DCE-MRI of the tumour vasculature in xenograft transplanted mice was performed to confirm vessel patency and demonstrate the multimodal capacity of the new cradle. Vessel characteristics such as diameter, and branching were quantified. Results Image artefacts originating from bones and out-of-field sample positioning were avoided whilst those resulting from motions were reduced significantly, thereby maximising the resolution that can be achieved with CT imaging in vivo. Tumour vessels ≥ 77 μm could be resolved and blood flow to the tumour remained functional. The diameter of each tumour vessel was determined and plotted as histograms and vessel branching maps were created. Multimodal imaging using this cradle assembly was preserved and demonstrated. Conclusions The presented imaging workflow minimised image artefacts arising from scanner induced vibrations, respiratory motion and radiopaque structures and enabled in vivo CT imaging

  10. Compromised trabecular microarchitecture and lower finite element estimates of radius and tibia bone strength in adults with turner syndrome: a cross-sectional study using high-resolution-pQCT.

    PubMed

    Hansen, Stinus; Brixen, Kim; Gravholt, Claus H

    2012-08-01

    Although bone mass appear ample for bone size in Turner syndrome (TS), epidemiological studies have reported an increased risk of fracture in TS. We used high-resolution peripheral quantitative computed tomography (HR-pQCT) to measure standard morphological parameters of bone geometry and microarchitecture, as well as estimated bone strength by finite element analysis (FEA) to assess bone characteristics beyond bone mineral density (BMD) that possibly contribute to the increased risk of fracture. Thirty-two TS patients (median age 35, range 20-61 years) and 32 healthy control subjects (median age 36, range 19-58 years) matched with the TS participants with respect to age and body-mass index were studied. A full region of interest (ROI) image analysis and a height-matched ROI analysis adjusting for differences in body height between groups were performed. Mean bone cross-sectional area was lower in TS patients in radius (-15%) and tibia (-13%) (both p < 0.01) whereas cortical thickness was higher in TS patients in radius (18%, p < 0.01) but not in tibia compared to controls. Cortical porosity was lower in TS patients at both sites (-32% in radius, -36% in tibia, both p < 0.0001). Trabecular integrity was compromised in TS patients with lower bone volume per tissue volume (BV/TV) (-27% in radius, -22% in tibia, both p < 0.0001), trabecular number (-27% in radius, -12% in tibia, both p < 0.05), and higher trabecular spacing (54% in radius, 23% in tibia, both p < 0.01). In the height-matched ROI analysis, differences remained significant apart from total area at both sites, cortical thickness in radius, and trabecular number in tibia. FEA estimated failure load was lower in TS patients in both radius (-11%) and tibia (-16%) (both p < 0.01) and remained significantly lower in the height-matched ROI analysis. Conclusively, TS patients had compromised trabecular microarchitecture and lower bone strength at both skeletal sites, which may partly

  11. Helmholtz-pair transmit coil with integrated receive array for high-resolution MRI of trabecular bone in the distal tibia at 7 T

    NASA Astrophysics Data System (ADS)

    Wright, Alexander C.; Lemdiasov, Rostislav; Connick, Thomas J.; Bhagat, Yusuf A.; Magland, Jeremy F.; Song, Hee Kwon; Toddes, Steven P.; Ludwig, Reinhold; Wehrli, Felix W.

    2011-05-01

    A Helmholtz-pair local transmit RF coil with an integrated four-element receive array RF coil and foot immobilization platform was designed and constructed for imaging the distal tibia in a whole-body 7 T MRI scanner. Simulations and measurements of the B1 field distribution of the transmit coil are described, along with SAR considerations for operation at 7 T. Results of imaging the trabecular bone of three volunteers at 1.5 T, 3 T and 7 T are presented, using identical 1.5 T and 3 T versions of the 7 T four-element receive array. The spatially registered images reveal improved visibility for individual trabeculae and show average gains in SNR of 2.8× and 4.9× for imaging at 7 T compared to 3 T and 1.5 T, respectively. The results thus display an approximately linear dependence of SNR with field strength and enable the practical utility of 7 T scanners for micro-MRI of trabecular bone.

  12. High Resolution Formaldehyde Photochemistry

    NASA Astrophysics Data System (ADS)

    Ernest, C. T.; Bauer, D.; Hynes, A. J.

    2010-12-01

    Formaldehyde (HCHO) is the most abundant and most important organic carbonyl compound in the atmosphere. The sources of formaldehyde are the oxidation of methane, isoprene, acetone, and other volatile organic compounds (VOCs); fossil fuel combustion; and biomass burning. The dominant loss mechanism for formaldehyde is photolysis which occurs via two pathways: (R1) HCHO + hv → HCO + H (R2) HCHO + hv → H2 + CO The first pathway (R1) is referred to as the radical channel, while the second pathway (R2) is referred to as the molecular channel. The products of both pathways play a significant role in atmospheric chemistry. The CO that is produced in the molecular channel undergoes further oxidation to produce CO2. Under atmospheric conditions, the H atom and formyl radical that are produced in the radical channel undergo rapid reactions with O2 to produce the hydroperoxyl radical (HO2) via (R3) and (R4). (R3) HCO + O2 → HO2 + CO (R4) H + O2 → HO2 Thus, for every photon absorbed, the photolysis of formaldehyde can contribute one CO2 molecule to the global greenhouse budget or two HO2 radicals to the tropospheric HOx (OH + HO2) cycle. The HO2 radicals produced during formaldehyde photolysis have also been implicated in the formation of photochemical smog. The HO2 radicals act as radical chain carriers and convert NO to NO2, which ultimately results in the catalytic production of O3. Constraining the yield of HO2 produced via HCHO photolysis is essential for improving tropospheric chemistry models. In this study, both the absorption cross section and the quantum yield of the radical channel (R1) were measured at high resolution over the tropospherically relevant wavelength range 304-330 nm. For the cross section measurements a narrow linewidth Nd:YAG pumped dye laser was used with a multi-pass cell. Partial pressures of HCHO were kept below 0.3 torr. Simultaneous measurement of OH LIF in a flame allowed absolute calibration of the wavelength scale. Pressure

  13. Assessment of 3-month changes in bone microstructure under anti-TNFα therapy in patients with rheumatoid arthritis using high-resolution peripheral quantitative computed tomography (HR-pQCT).

    PubMed

    Shimizu, Tomohiro; Choi, Hyo Jin; Heilmeier, Ursula; Tanaka, Matthew; Burghardt, Andrew J; Gong, Jingshan; Chanchek, Nattagan; Link, Thomas M; Graf, Jonathan; Imboden, John B; Li, Xiaojuan

    2017-10-04

    Although one study showed minimal progression of erosions in patients with rheumatoid arthritis (RA) one year after TNFα inhibition therapy, no studies have investigated very early bone changes after initiation of anti-TNFα treatment. We investigated the effects of 3-month anti-TNFα treatment on bone erosion progression and bone microarchitecture in RA patients using high-resolution peripheral quantitative computed tomography (HR-pQCT). Patients with RA (n = 27) (17 in the anti-TNFα and 10 in the MTX-only group) underwent assessment of disease activity score in 28 joints (DAS-28), radiographs, 3-T magnetic resonance imaging (MRI) and HR-pQCT of metacarpophalangeal and wrist joints at baseline and 3 months. HR-pQCT-derived erosion volume, joint volume/width and bone microarchitecture were computed and joint destruction was assessed using Sharp and RAMRIS scorings on radiographs and MRI, respectively. Overall, 73 erosions were identified by HR-pQCT at baseline. Over 3 months, the anti-TNFα group had decreased mean erosion volume; increased erosion volume was observed in one clinical non-responder. The MTX-only group in contrast, trended toward increasing erosion volume despite low disease activity. In the anti-TNFα group, joint-space width and volume of MCP joints decreased significantly and was positively correlated with erosion volume changes (R (2) = 0.311, p = 0.013; R (2) = 0.527, p = 0.003, respectively). In addition, erosion volume changes were significantly negatively correlated with changes in trabecular bone mineral density (R (2) = 0.353, p = 0.020) in this group. We observed significant correlation between percentage change in erosion volume and change in DAS-28 erythrocyte sedimentation rate and C-reactive protein CRP scores (R (2) = 0.558, p < 0.001; R (2) = 0.745, p < 0.001, respectively) in all patients. Using HR-pQCT, our data suggest that anti-TNFα treatment prevents erosion progression and

  14. Melanotic neuroectodermal tumor of infancy arising in the temporal bone.

    PubMed

    Zhang, Jian-guo; Zhao, Rui-jiao; Kong, Ling-fei

    2015-04-01

    Melanotic neuroectodermal tumor of infancy is a rare melanin-containing neoplasm with locally aggressive and rapid expansile growth, usually involving the maxilla, skull, and mandible of early infancy. Radical surgery is critical for a long-term outcome. We present a case of 14-month-old girl with rapid-growing subcutaneous mass arising in the right temporal bone and extending intracranially on computed tomographic scan. Radical surgery was performed. A brownish-black tumor composed of large pigmented epithelioid cells, positive for cytokeratins and HMB-45, and nests of small neuroblast-like cells positive for neuron-specific enolase and synaptophysin, was diagnosed as melanotic neuroectodermal tumor of infancy. The patient remained well without evidence of recurrence for 1 year after surgery. Clinicopathological features, management alternatives and outcome were discussed. © The Author(s) 2013.

  15. High resolution time interval meter

    DOEpatents

    Martin, A.D.

    1986-05-09

    Method and apparatus are provided for measuring the time interval between two events to a higher resolution than reliability available from conventional circuits and component. An internal clock pulse is provided at a frequency compatible with conventional component operating frequencies for reliable operation. Lumped constant delay circuits are provided for generating outputs at delay intervals corresponding to the desired high resolution. An initiation START pulse is input to generate first high resolution data. A termination STOP pulse is input to generate second high resolution data. Internal counters count at the low frequency internal clock pulse rate between the START and STOP pulses. The first and second high resolution data are logically combined to directly provide high resolution data to one counter and correct the count in the low resolution counter to obtain a high resolution time interval measurement.

  16. Anatomy-Specific Virtual Reality Simulation in Temporal Bone Dissection.

    PubMed

    Locketz, Garrett D; Lui, Justin T; Chan, Sonny; Salisbury, Kenneth; Dort, Joseph C; Youngblood, Patricia; Blevins, Nikolas H

    2017-03-01

    Objective To evaluate the effect of anatomy-specific virtual reality (VR) surgical rehearsal on surgeon confidence and temporal bone dissection performance. Study Design Prospective pre- and poststudy of a novel virtual surgical rehearsal platform. Setting Academic otolaryngology-head and neck surgery residency training programs. Subjects and Methods Sixteen otolaryngology-head and neck surgery residents from 2 North American training institutions were recruited. Surveys were administered to assess subjects' baseline confidence in performing 12 subtasks of cortical mastoidectomy with facial recess. A cadaver temporal bone was randomly assigned to each subject. Cadaver specimens were scanned with a clinical computed tomography protocol, allowing the creation of anatomy-specific models for use in a VR surgical rehearsal platform. Subjects then rehearsed a virtual mastoidectomy on data sets derived from their specimens. Surgical confidence surveys were administered again. Subjects then dissected assigned cadaver specimens, which were blindly graded with a modified Welling scale. A final survey assessed the perceived utility of rehearsal on dissection performance. Results Of 16 subjects, 14 (87.5%) reported a significant increase in overall confidence after conducting an anatomy-specific VR rehearsal. A significant correlation existed between perceived utility of rehearsal and confidence improvement. The effect of rehearsal on confidence was dependent on trainee experience and the inherent difficulty of the surgical subtask. Postrehearsal confidence correlated strongly with graded dissection performance. Subjects rated anatomy-specific rehearsal as having a moderate to high contribution to their dissection performance. Conclusion Anatomy-specific virtual rehearsal improves surgeon confidence in performing mastoid dissection, dependent on surgeon experience and task difficulty. The subjective confidence gained through rehearsal correlates positively with subsequent

  17. Long-term results of surgery for temporal bone paragangliomas.

    PubMed

    Briner, H R; Linder, T E; Pauw, B; Fisch, U

    1999-04-01

    Assessment of the long-term results of surgery for temporal bone paragangliomas with special consideration of the patient's ability to cope with the functional deficits. Retrospective review of 36 patients who had undergone resection of a temporal bone paraganglioma 10 to 15 years previously. Assessment of the patients' subjective view of the functional outcome and quality of life by a questionnaire. Clinical records were reviewed regarding size of tumor, technique of surgery, supportive therapy, and tumor recurrence. Patients were sent a 50-item questionnaire evaluating their quality of life and the preoperative and postoperative function of cranial nerves VII through XII. A complete tumor removal was achieved in 30 patients (83%). There was only one tumor recurrence. The major negative effects of surgery involved hearing and dysphagia, which deterioriated in 14 and 12 patients, respectively. Thirty-five of the 36 patients (97%) reported that, despite deterioration, the cranial nerve deficits were still acceptable. Seventy-five percent of the patients regained their preoperative quality of life and 97% returned to their previous occupation in 1 to 2 years. The otologic extradural approach allowed complete tumor removal in 83%, with minimal perioperative morbidity. No surgically induced central nervous system lesions occured. Tracheostomy was avoided and all patients resumed oral feeding. Full rehabilitation after removal of class C and CD paragangliomas may take 1 to 2 years. However, the fact that 97% of the patients finally resumed normal social life showed the ability of most patients to cope with the sequelae of surgery even in class C and CD paragangliomas.

  18. Anatomic and Quantitative Temporal Bone CT for Preoperative Assessment of Branchio-Oto-Renal Syndrome.

    PubMed

    Ginat, D T; Ferro, L; Gluth, M B

    2016-12-01

    We describe the temporal bone computed tomography (CT) findings of an unusual case of branchio-oto-renal syndrome with ectopic ossicles that are partially located in the middle cranial fossa. We also describe quantitative temporal bone CT assessment pertaining to cochlear implantation in the setting of anomalous cochlear anatomy associated with this syndrome.

  19. Prevalence of Temporal Bone Fractures in Patients with Mandibular Fractures Using Multidetector-Row CT.

    PubMed

    Ogura, I; Kaneda, T; Sasaki, Y; Buch, K; Sakai, O

    2015-06-01

    Temporal bone fracture after mandibular trauma is thought to be rare, and its prevalence has not been reported in the literature. The purpose of this study was to investigate the prevalence of temporal bone fractures in patients with mandibular fractures and the relationship between temporal bone fractures and the mandibular fracture location using multidetector-row computed tomography (MDCT). A prospective study was performed in 201 patients with mandibular fractures who underwent 64-MDCT scans. The mandibular fracture locations were classified as median, paramedian, angle, and condylar types. Statistical analysis for the relationship between prevalence of temporal bone fractures and mandibular fracture locations was performed using χ(2) test with Fisher's exact test. A P-value < 0.05 was considered statistically significant. The percentage of cases with temporal bone fracture was 3.0 % of all patients with mandibular fractures and 19.0 % of those with multiple mandibular fractures of paramedian and condylar type. There was a significant relationship between the incidence of temporal bone fracture and the paramedian- and condylar-type mandibular fracture (P = 0.001). Multiple mandibular fractures of paramedian and condylar type may be a stronger indicator for temporal bone fractures. This study suggests that patients with mandibular fracture, especially the paramedian and condylar type, should be examined for coexisting temporal bone fracture using MDCT.

  20. Roller blade falls--a new cause of temporal bone fractures: case reports.

    PubMed

    Weinberger, D G; Selesnick, S H

    1994-09-01

    Skating on wheels-in-line skates (roller blading) is an increasingly popular activity. We present two cases of temporal bone fractures from roller blading falls, and review the literature on temporal bone fractures resulting from recreational activities. Since trauma from roller blading may result in significant morbidity, the use of helmets is strongly recommended.

  1. Primary pericranial Ewing's sarcoma on the temporal bone: A case report

    PubMed Central

    Kawano, Hiroto; Nitta, Naoki; Ishida, Mitsuaki; Fukami, Tadateru; Nozaki, Kazuhiko

    2016-01-01

    Background: Primary Ewing's sarcoma originating in the pericranium is an extremely rare disease entity. Case Description: A 9-year-old female patient was admitted to our department due to a left temporal subcutaneous mass. The mass was localized under the left temporal muscle and attached to the surface of the temporal bone. Head computed tomography revealed a mass with bony spicule formation on the temporal bone, however, it did not show bone destruction or intracranial invasion. F-18 fluorodeoxyglucose positron emission tomography showed no lesions other than the mass on the temporal bone. Magnetic resonance imaging showed that the mass was located between the temporal bone and the pericranium. The mass was completely resected with the underlying temporal bone and the overlying deep layer of temporal muscle, and was diagnosed as primary Ewing's sarcoma. Because the tumor was located in the subpericranium, we created a new classification, “pericranial Ewing's sarcoma,” and diagnosed the present tumor as pericranial Ewing's sarcoma. Conclusion: We herein present an extremely rare case of primary pericranial Ewing's sarcoma that developed on the temporal bone. PMID:27308095

  2. [A general review on the procedures in a human temporal bone laboratory].

    PubMed

    Oktay, Mehmet Faruk; Cüreoğlu, Sebahattin; Schachern, Patricia A; Paparella, Micheal M

    2006-01-01

    Structures of the human ear are usually inaccessible during life for examination of pathologic changes of the underlying disease, which is only possible with postmortem studies of the human temporal bone. Human temporal bone laboratories serve as a unique source of material for research in this respect. They enable comparison between histologic findings of temporal bone sections and the ear pathologies documented prior to death, as well as comparison of diseased ears with any selected temporal bone specimens, both of which provide invaluable knowledge to be shared among researchers and other laboratories. This article aims to provide insight into the functions of temporal bone laboratories and to familiarize the reader with histopathologic studies conducted therein.

  3. An individual drug-therapy and genetic testing report of temporal bone verrucous carcinoma

    PubMed Central

    Tan, Haolei; Liu, Yong; Zhu, Gangcai; Pi, Leiming; Huang, Donghai; Zhang, Xin

    2014-01-01

    Objective To investigate the pathology and pathogenesis of and treatment methods for temporal bone verrucous carcinoma. Materials and methods A single-patient report of verrucous carcinoma on the left external auditory canal is presented and analyzed along with all cases of temporal bone verrucous carcinoma that have been documented in the English literature. Results Most of the patients with verrucous carcinoma of the temporal bone have histories of surgery, trauma, or infection, and verrucous carcinomas are sensitive to antimicrotubule chemotherapeutic medicines. Adjuvant radiation therapy is not effective, but surgical treatment might be relatively more effective. Conclusion Temporal bone verrucous carcinoma has a poor prognosis; therefore, the preferred treatment is surgical resection facilitated with antimicrotubule chemotherapeutic treatment. Adjuvant radiation therapy is not a preferred treatment for temporal bone verrucous carcinoma. PMID:25214794

  4. An individual drug-therapy and genetic testing report of temporal bone verrucous carcinoma.

    PubMed

    Tan, Haolei; Liu, Yong; Zhu, Gangcai; Pi, Leiming; Huang, Donghai; Zhang, Xin

    2014-01-01

    To investigate the pathology and pathogenesis of and treatment methods for temporal bone verrucous carcinoma. A single-patient report of verrucous carcinoma on the left external auditory canal is presented and analyzed along with all cases of temporal bone verrucous carcinoma that have been documented in the English literature. Most of the patients with verrucous carcinoma of the temporal bone have histories of surgery, trauma, or infection, and verrucous carcinomas are sensitive to antimicrotubule chemotherapeutic medicines. Adjuvant radiation therapy is not effective, but surgical treatment might be relatively more effective. Temporal bone verrucous carcinoma has a poor prognosis; therefore, the preferred treatment is surgical resection facilitated with antimicrotubule chemotherapeutic treatment. Adjuvant radiation therapy is not a preferred treatment for temporal bone verrucous carcinoma.

  5. Case of bilateral pneumolabyrinth presenting as sudden, bilateral deafness, without temporal bone fracture, after a fall.

    PubMed

    Lee, E J; Yang, Y S; Yoon, Y J

    2012-07-01

    We report a case of bilateral pneumolabyrinth presenting as sudden, bilateral deafness, without temporal bone fracture, after a fall. A 49-year-old man presented with sudden, bilateral deafness and whirling vertigo, without any other neurological manifestations. Temporal bone computed tomography clearly demonstrated the presence of air in the vestibule and cochlea on both sides. However, there was no definite fracture line, ossicular chain anomaly or soft tissue density in the temporal bone or middle-ear cavity. The patient was treated conservatively. Unfortunately, there was no improvement in his hearing. Pneumolabyrinth is an uncommon condition in which air is present in the vestibule or cochlea. It is rarely found, even with fractures violating the otic capsule or with transverse fractures of the temporal bone. In addition, its bilateral occurrence is extremely rare. In this article, we describe a case of bilateral pneumolabyrinth presenting as sudden, bilateral deafness, without temporal bone fracture, an occurrence which has not previously been reported.

  6. Elastic properties and strain-to-crack-initiation of calcium phosphate bone cements: Revelations of a high-resolution measurement technique.

    PubMed

    Ajaxon, Ingrid; Acciaioli, Alice; Lionello, Giacomo; Ginebra, Maria-Pau; Öhman-Mägi, Caroline; Baleani, Massimiliano; Persson, Cecilia

    2017-10-01

    Calcium phosphate cements (CPCs) should ideally have mechanical properties similar to those of the bone tissue the material is used to replace or repair. Usually, the compressive strength of the CPCs is reported and, more rarely, the elastic modulus. Conversely, scarce or no data are available on Poisson's ratio and strain-to-crack-initiation. This is unfortunate, as data on the elastic response is key to, e.g., numerical model accuracy. In this study, the compressive behaviour of brushite, monetite and apatite cements was fully characterised. Measurement of the surface strains was done using a digital image correlation (DIC) technique, and compared to results obtained with the commonly used built-in displacement measurement of the materials testers. The collected data showed that the use of fixed compression platens, as opposed to spherically seated ones, may in some cases underestimate the compressive strength by up to 40%. Also, the built-in measurements may underestimate the elastic modulus by up to 62% as compared to DIC measurements. Using DIC, the brushite cement was found to be much stiffer (24.3 ± 2.3GPa) than the apatite (13.5 ± 1.6GPa) and monetite (7.1 ± 1.0GPa) cements, and elastic moduli were inversely related to the porosity of the materials. Poisson's ratio was determined to be 0.26 ± 0.02 for brushite, 0.21 ± 0.02 for apatite and 0.20 ± 0.03 for monetite. All investigated CPCs showed low strain-to-crack-initiation (0.17-0.19%). In summary, the elastic modulus of CPCs is substantially higher than previously reported and it is concluded that an accurate procedure is a prerequisite in order to properly compare the mechanical properties of different CPC formulations. It is recommended to use spherically seated platens and measuring the strain at a relevant resolution and on the specimen surface. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

  7. Hearing levels in patients with microtia: correlation with temporal bone malformation.

    PubMed

    Ishimoto, Shin-ichi; Ito, Ken; Karino, Shotaro; Takegoshi, Hideki; Kaga, Kimitaka; Yamasoba, Tatsuya

    2007-03-01

    To evaluate the relationship between hearing level and temporal bone abnormalities in patients with microtia. Retrospective case series study between 1992 and 2004. Academic, tertiary care referral medical center. We evaluated 115 ears of 89 patients (68 males, 21 females; mean age, 11 yr; range, 5-44 yr) with microtia. Hearing level was examined in patients with microtia. Developmental abnormalities of the temporal bone were evaluated by Jahrsdoerfer's computed tomography (CT) scoring system using high-resolution CT (HRCT) scans of the temporal bone. Temporal bone malformation scores were divided into four subgroups: ossicular development, windows connected to the cochlea, aeration of the middle ear cavity, and facial nerve aberration. Patients were divided into the stenosis and atresia groups on the basis of the appearance of the external auditory canal (EAC). We also evaluated the relationships between hearing level and four subtotal scores of the HRCT findings in the stenosis and atresia groups. There was no relationship between hearing level and total points of HRCT scoring system or between hearing level and severity of microtia scored by Marx classification. With regard to subtotal points related to ossicles (4 points), the hearing level in ears with low scores (<2) (64.7 +/- 1.6 dB) was significantly different (P = .03) from that in ears with high scores (> or =2) (54.0 +/- 2.8 dB) in the stenosis group. In the atresia group, the hearing level was 64.3 +/- 2.2 dB in ears with low scores and 62.3 +/- 1.1 in ears with high scores (P > .5). As for subtotal points related to the windows connected to cochlea (2 points), the hearing level was 64.8 +/- 2.6 dB in ears with low scores (0) and 55.9 +/- 2.4 dB in ears with high scores (> = 1) in the stenosis group. In the atresia group, the hearing level was 67.7 +/- 2.3 dB in ears with low scores and 61.5 +/- 1.0 in ears with high scores. There was significant difference between ears with low and high scores in the

  8. Assessment of skills using a virtual reality temporal bone surgery simulator.

    PubMed

    Linke, R; Leichtle, A; Sheikh, F; Schmidt, C; Frenzel, H; Graefe, H; Wollenberg, B; Meyer, J E

    2013-08-01

    Surgery on the temporal bone is technically challenging due to its complex anatomy. Precise anatomical dissection of the human temporal bone is essential and is fundamental for middle ear surgery. We assessed the possible application of a virtual reality temporal bone surgery simulator to the education of ear surgeons. Seventeen ENT physicians with different levels of surgical training and 20 medical students performed an antrotomy with a computer-based virtual temporal bone surgery simulator. The ease, accuracy and timing of the simulated temporal bone surgery were assessed using the automatic assessment software provided by the simulator device and additionally with a modified Final Product Analysis Scale. Trained ENT surgeons, physicians without temporal bone surgical training and medical students were all able to perform the antrotomy. However, the highly trained ENT surgeons were able to complete the surgery in approximately half the time, with better handling and accuracy as assessed by the significant reduction in injury to important middle ear structures. Trained ENT surgeons achieved significantly higher scores using both dissection analysis methods. Surprisingly, there were no significant differences in the results between medical students and physicians without experience in ear surgery. The virtual temporal bone training system can stratify users of known levels of experience. This system can be used not only to improve the surgical skills of trained ENT surgeons for more successful and injury-free surgeries, but also to train inexperienced physicians/medical students in developing their surgical skills for the ear.

  9. Differential Intracochlear Sound Pressure Measurements in Normal Human Temporal Bones

    NASA Astrophysics Data System (ADS)

    Nakajima, Hideko Heidi; Dong, Wei; Olson, Elizabeth S.; Merchant, Saumil N.; Ravicz, Michael E.; Rosowski, John J.

    2009-02-01

    We present the first simultaneous sound pressure measurements in scala vestibuli and scala tympani of the cochlea in human cadaveric temporal bones. Micro-scale fiberoptic pressure sensors enabled the study of differential sound pressure at the cochlear base. This differential pressure is the input to the cochlear partition, driving cochlear waves and auditory transduction. Results showed that: pressure of scala vestibuli was much greater than scala tympani except at low and high frequencies where scala tympani pressure affects the input to the cochlea; the differential pressure proved to be an excellent measure of normal ossicular transduction of sound (shown to decrease 30-50 dB with ossicular disarticulation, whereas the individual scala pressures were significantly affected by non-ossicular conduction of sound at high frequencies); the middle-ear gain and differential pressure were generally bandpass in frequency dependence; and the middle-ear delay in the human was over twice that of the gerbil. Concurrent stapes velocity measurements allowed determination of the differential impedance across the partition and round-window impedance. The differential impedance was generally resistive, while the round-window impedance was consistent with a compliance in conjunction with distributed inertia and damping. Our techniques can be used to study inner-ear conductive pathologies (e.g., semicircular dehiscence), as well as non-ossicular cochlear stimulation (e.g., round-window stimulation) - situations that cannot be completely quantified by measurements of stapes velocity or scala-vestibuli pressure by themselves.

  10. Histopathologic ear findings of syphilis: a temporal bone study.

    PubMed

    Hızlı, Ömer; Hızlı, Pelin; Kaya, Serdar; Monsanto, Rafael da Costa; Paparella, Michael M; Cureoglu, Sebahattin

    2016-09-01

    To the best of our knowledge, histopathologic studies of syphilitic ears have generally focused on hydropic changes; so far, no such studies have investigated peripheral vestibular otopathology using differential interference contrast microscopy, in patients with syphilis. For this study, we examined 13 human temporal bone samples from 8 patients with a history of syphilis. Using conventional light microscopy, we performed qualitative histopathologic assessment. In addition, using differential interference contrast microscopy, we performed type I and type II vestibular hair cell counts on each vestibular sense organ with minimal autolysis; in which the neuroepithelium was oriented perpendicular to the plane of section. We then compared vestibular hair cell densities (cells per 0.01 mm² surface area) in the syphilis group vs. the control group. In the syphilis group, we observed precipitate in the endolymphatic or perilymphatic spaces in 1 (7.7 %) of the samples and endolymphatic hydrops in eight (61.5 %) of the samples. Hydrops involved the cochlea (four samples) and/or saccule (four samples). In addition, the syphilis group experienced a significant loss of type II vestibular hair cells in the maculae of the utricle and saccule, and in the cristae of the lateral and posterior semicircular canals, as compared with the control group (P < 0.05).

  11. Pre-operative preparation for otologic surgery: temporal bone simulation

    PubMed Central

    Sethia, Rishabh; Wiet, Gregory J.

    2015-01-01

    Purpose of review The field of temporal bone simulation (TBS) has largely focused on the development and validation of simulators as training and assessment tools. However, as technology has progressed over the years, researchers have envisioned new clinical applications for simulators extending to pre-operative surgical planning and case rehearsal. The purpose of this article is to review the current state of the art in TBS and to highlight recent advancements in the field. Due to space limitations, we will limit our discussion to computer-based virtual reality (VR) simulators. Recent findings A review of the recent literature on TBS revealed very limited application of VR simulators for pre-operative preparation. Current evidence suggests limitations in fidelity preclude successful patient-specific case rehearsal using VR simulation. Further investigation and clinical evaluation are required to validate its use outside of training and skill assessment. Summary This article provides an overview of the current use of VR simulators with emphasis on pre-operative planning. We evaluate the limitations of the technology, and discuss potential areas of improvement for the future. More studies are necessary to assess the value of VR simulation for pre-operative preparation. PMID:26339966

  12. Outcomes of temporal bone resection for locally advanced parotid cancer.

    PubMed

    Mehra, Saral; Morris, Luc G; Shah, Jatin; Bilsky, Mark; Selesnick, Samuel; Kraus, Dennis H

    2011-11-01

    This study was conducted to report outcomes and identify factors predictive of survival and recurrence in patients undergoing lateral temporal bone resection (LTBR) as part of an extended radical parotidectomy for parotid cancer. This is a retrospective cohort study which includes all patients undergoing LTBR for parotid cancer between 1994 and 2010 at two affiliated academic centers. Survival and recurrence rates were analyzed using the Kaplan-Meier method and Cox multivariate regression. A total of 12 patients with median follow-up duration of 30.6 months were included: 6 de novo cases and 6 patients referred after local recurrence. Actuarial locoregional control at 2 years was 73%. Most patients (11; 92%) developed disease recurrence with distant metastases the most common site of first failure (83%). Overall and disease-specific survival rates were 80% at 2 years and 22.5% at 5 years. Recurrence-free survival (RFS) was 67% at 2 years and 8.3% at 5 years. On multivariate analysis, surgical margin status was an independent predictor of RFS (hazard ratio = 3.85, p = 0.045). In advanced parotid cancer, LTBR with a goal of gross total resection offers good locoregional control with an acceptable complication rate. The benefits of this surgery must be balanced with the morbidity and low likelihood of long-term survival, with most patients ultimately experiencing disease recurrence and death.

  13. Outcomes of Temporal Bone Resection for Locally Advanced Parotid Cancer

    PubMed Central

    Mehra, Saral; Morris, Luc G.; Shah, Jatin; Bilsky, Mark; Selesnick, Samuel; Kraus, Dennis H.

    2011-01-01

    This study was conducted to report outcomes and identify factors predictive of survival and recurrence in patients undergoing lateral temporal bone resection (LTBR) as part of an extended radical parotidectomy for parotid cancer. This is a retrospective cohort study which includes all patients undergoing LTBR for parotid cancer between 1994 and 2010 at two affiliated academic centers. Survival and recurrence rates were analyzed using the Kaplan-Meier method and Cox multivariate regression. A total of 12 patients with median follow-up duration of 30.6 months were included: 6 de novo cases and 6 patients referred after local recurrence. Actuarial locoregional control at 2 years was 73%. Most patients (11; 92%) developed disease recurrence with distant metastases the most common site of first failure (83%). Overall and disease-specific survival rates were 80% at 2 years and 22.5% at 5 years. Recurrence-free survival (RFS) was 67% at 2 years and 8.3% at 5 years. On multivariate analysis, surgical margin status was an independent predictor of RFS (hazard ratio = 3.85, p = 0.045). In advanced parotid cancer, LTBR with a goal of gross total resection offers good locoregional control with an acceptable complication rate. The benefits of this surgery must be balanced with the morbidity and low likelihood of long-term survival, with most patients ultimately experiencing disease recurrence and death. PMID:22547966

  14. Rusty green stained temporal bone associated with exposure to tetracycline: an unusual presentation of black bone disease.

    PubMed

    Farahnik, B; Zaghi, S; Hendizadeh, L; Gopen, Q

    2015-03-01

    To review the phenomenon and implications of temporal bone and craniofacial bone staining in the context of prolonged exposure to tetracycline antibiotic. Case report and literature review. A 52-year-old male with a 5-year history of tetracycline use presented to undergo tympanomastoidectomy and was found to have an unusual rusty green pigmentation of the entire aspect of the exposed temporal bone. A literature review revealed more than 20 cases of tetracycline-induced pigmentation of intraoral maxillary and mandibular bone, and 2 prior cases involving the cranial bones. Tissue and organ pigmentation is an unexpected and unfavourable consequence of the use of tetracyclines, particularly minocycline. Tetracycline is contraindicated in children because of the risk for dysosteogenesis and enamel hypoplasia. In adults, although the unusual staining may present as an unexpected dilemma upon surgical exposure, current research shows no significant clinical consequences for this type of pigmentation.

  15. Fuzzy logic structure analysis of trabecular bone of the calcaneus to estimate proximal femur fracture load and discriminate subjects with and without vertebral fractures using high-resolution magnetic resonance imaging at 1.5 T and 3 T.

    PubMed

    Patel, Priyesh V; Eckstein, Felix; Carballido-Gamio, Julio; Phan, Catherine; Matsuura, Maiko; Lochmüller, Eva-Maria; Majumdar, Sharmila; Link, Thomas M

    2007-10-01

    Newly developed fuzzy logic-derived structural parameters were used to characterize trabecular bone architecture in high-resolution magnetic resonance imaging (HR-MRI) of human cadaver calcaneus specimens. These parameters were compared to standard histomorphological structural measures and analyzed concerning performance in discriminating vertebral fracture status and estimating proximal femur fracture load. Sets of 60 sagittal 1.5 T and 3.0 T HR-MRI images of the calcaneus were obtained in 39 cadavers using a fast gradient recalled echo sequence. Structural parameters equivalent to bone histomorphometry and fuzzy logic-derived parameters were calculated using two chosen regions of interest. Calcaneal, spine, and hip bone mineral density (BMD) measurements were also obtained. Fracture status of the thoracic and lumbar spine was assessed on lateral radiographs. Finally, mechanical strength testing of the proximal femur was performed. Diagnostic performance in discriminating vertebral fracture status and estimating femoral fracture load was calculated using regression analyses, two-tailed t-tests of significance, and receiver operating characteristic (ROC) analyses. Significant correlations were obtained at both field strengths between all structural and fuzzy logic parameters (r up to 0.92). Correlations between histomorphological or fuzzy logic parameters and calcaneal BMD were mostly significant (r up to 0.78). ROC analyses demonstrated that standard structural parameters were able to differentiate persons with and without vertebral fractures (area under the curve [A(Z)] up to 0.73). However, none of the parameters obtained in the 1.5-T images and none of the fuzzy logic parameters discriminated persons with and without vertebral fractures. Significant correlations were found between fuzzy or structural parameters and femoral fracture load. Using multiple regression analysis, none of the structural or fuzzy parameters were found to add discriminative value to BMD

  16. Developing effective automated feedback in temporal bone surgery simulation.

    PubMed

    Wijewickrema, Sudanthi; Piromchai, Patorn; Zhou, Yun; Ioannou, Ioanna; Bailey, James; Kennedy, Gregor; O'Leary, Stephen

    2015-06-01

    We aim to test the effectiveness, accuracy, and usefulness of an automated feedback system in facilitating skill acquisition in virtual reality surgery. We evaluate the performance of the feedback system through a randomized controlled trial of 24 students allocated to feedback and nonfeedback groups. The feedback system was based on the Melbourne University temporal bone surgery simulator. The study was conducted at the simulation laboratory of the Royal Victorian Eye and Ear Hospital, Melbourne. The study participants were medical students from the University of Melbourne, who were asked to perform virtual cortical mastoidectomy on the simulator. The extent to which the drilling behavior of the feedback and nonfeedback groups differed was used to evaluate the effectiveness of the system. Its accuracy was determined through a postexperiment observational assessment of recordings made during the experiment by an expert surgeon. Its usability was evaluated using students' self-reports of their impressions of the system. A Friedman's test showed that there was a significant improvement in the drilling performance of the feedback group, χ(2)(1) = 14.450, P < .001. The postexperiment assessment demonstrated that the system provided timely feedback (when trainee behavior was detected) 88.6% of the time and appropriate feedback (accurate advice) 84.2% of the time. Participants' opinions about the usefulness of the system were highly positive. The automated feedback system was observed to be effective in improving surgical technique, and the provided feedback was found to be accurate and useful. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  17. High resolution extremity CT for biomechanics modeling

    SciTech Connect

    Ashby, A.E.; Brand, H.; Hollerbach, K.; Logan, C.M.; Martz, H.E.

    1995-09-23

    With the advent of ever more powerful computing and finite element analysis (FEA) capabilities, the bone and joint geometry detail available from either commercial surface definitions or from medical CT scans is inadequate. For dynamic FEA modeling of joints, precise articular contours are necessary to get appropriate contact definition. In this project, a fresh cadaver extremity was suspended in parafin in a lucite cylinder and then scanned with an industrial CT system to generate a high resolution data set for use in biomechanics modeling.

  18. Osteoradionecrosis of sphenoid and temporal bones in a patient with maxillary sinus carcinoma: A case report

    SciTech Connect

    Inokuchi, T.; Sano, K.; Kaminogo, M. )

    1990-09-01

    A case of radionecrosis of sphenoid and temporal bones is reported. The patient received a combination of surgery, radiotherapy, and chemotherapy for his left maxillary sinus carcinoma. After the combined therapy, necrosis accompanying inflammation developed in the maxillary and temporal regions. Excision of the necrotic tissues was done, and the left ascending ramus of the mandible was resected because of persistent tumor mass at the left infratemporal fossa. Although the excision wound of the maxilla healed by epithelialization, an area of nonvital bone remained exposed in the temporal region, where progressive osteonecrosis with infection led to breakdown of the skin. The necrotic bones of the zygomatic arch and the sphenotemporal sutural region became visible through the skin defect, and computerized tomography scan revealed bone necrosis involving the inferolateral area and the base of the skull. Excision of the necrotic bone and reconstruction with sternocleidomastoid myocutaneous flap were performed.

  19. A high-resolution imaging technique using a whole-body, research photon counting detector CT system

    NASA Astrophysics Data System (ADS)

    Leng, S.; Yu, Z.; Halaweish, A.; Kappler, S.; Hahn, K.; Henning, A.; Li, Z.; Lane, J.; Levin, D. L.; Jorgensen, S.; Ritman, E.; McCollough, C.

    2016-03-01

    A high-resolution (HR) data collection mode has been introduced to a whole-body, research photon-counting-detector CT system installed in our laboratory. In this mode, 64 rows of 0.45 mm x 0.45 mm detector pixels were used, which corresponded to a pixel size of 0.25 mm x 0.25 mm at the iso-center. Spatial resolution of this HR mode was quantified by measuring the MTF from a scan of a 50 micron wire phantom. An anthropomorphic lung phantom, cadaveric swine lung, temporal bone and heart specimens were scanned using the HR mode, and image quality was subjectively assessed by two experienced radiologists. High spatial resolution of the HR mode was evidenced by the MTF measurement, with 15 lp/cm and 20 lp/cm at 10% and 2% modulation. Images from anthropomorphic phantom and cadaveric specimens showed clear delineation of small structures, such as lung vessels, lung nodules, temporal bone structures, and coronary arteries. Temporal bone images showed critical anatomy (i.e. stapes superstructure) that was clearly visible in the PCD system. These results demonstrated the potential application of this imaging mode in lung, temporal bone, and vascular imaging. Other clinical applications that require high spatial resolution, such as musculoskeletal imaging, may also benefit from this high resolution mode.

  20. High-Resolution US of Rheumatologic Diseases.

    PubMed

    Taljanovic, Mihra S; Melville, David M; Gimber, Lana H; Scalcione, Luke R; Miller, Margaret D; Kwoh, C Kent; Klauser, Andrea S

    2015-01-01

    For the past 15 years, high-resolution ultrasonography (US) is being routinely and increasingly used for initial evaluation and treatment follow-up of rheumatologic diseases. This imaging technique is performed by using high-frequency linear transducers and has proved to be a powerful diagnostic tool in evaluation of articular erosions, simple and complex joint and bursal effusions, tendon sheath effusions, and synovitis, with results comparable to those of magnetic resonance imaging, excluding detection of bone marrow edema. Crystal deposition diseases including gouty arthropathy and calcium pyrophosphate deposition disease (CPPD) have characteristic appearances at US, enabling differentiation between these two diseases and from inflammatory arthropathies. Enthesopathy, which frequently accompanies psoriatic and reactive arthritis, also has a characteristic appearance at high-resolution US, distinguishing these two entities from other inflammatory and metabolic arthropathies. The presence of Doppler signal in examined joints, bursae, and tendon sheaths indicates active synovitis. Microbubble echo contrast agents augment detection of tissue vascularity and may act in the future as a drug delivery vehicle. Frequently, joint, tendon sheath, and bursal fluid aspirations and therapeutic injections are performed under US guidance. The authors describe the high-resolution US technique including gray-scale, color or power Doppler, and contrast agent-enhanced US that is used in evaluation of rheumatologic diseases of the wrist and hand and the ankle and foot in their routine clinical practice. This article demonstrates imaging findings of normal joints, rheumatoid arthritis, gouty arthritis, CPPD, psoriatic and reactive arthritis, and osteoarthritis.

  1. Temporal bone osteomyelitis and temporoparietal abscess secondary to malignant otitis externa.

    PubMed

    Alva, B; Prasad, K Chandra; Prasad, S Chandra; Pallavi, S

    2009-11-01

    We report an advanced presentation of osteomyelitis of the temporal bone secondary to malignant otitis externa. We present a case report and a review of the world literature concerning osteomyelitis of the temporal bone secondary to malignant otitis externa. A 60-year-old diabetic man developed osteomyelitis of the temporal bone and a temporoparietal abscess as advanced complications of malignant otitis externa. He was successfully treated in our institution using a post aural incision after draining the abscess and excising the fistula, a modified radical mastoidectomy with canal wall down procedure with sequesterectomy and debridement of surrounding area done. The terms 'osteomyelitis of the temporal bone', 'skull base osteomyelitis' and 'malignant otitis externa' have not been clearly defined, and have in the past often been used interchangeably in the literature. Osteomyelitis of the temporal bone can occur secondary to malignant otitis externa, acute otitis media, chronic suppurative otitis media or trauma. Here, we present the management of an advanced case of osteomyelitis of the temporal bone.

  2. High resolution digital delay timer

    DOEpatents

    Martin, Albert D.

    1988-01-01

    Method and apparatus are provided for generating an output pulse following a trigger pulse at a time delay interval preset with a resolution which is high relative to a low resolution available from supplied clock pulses. A first lumped constant delay (20) provides a first output signal (24) at predetermined interpolation intervals corresponding to the desired high resolution time interval. Latching circuits (26, 28) latch the high resolution data (24) to form a first synchronizing data set (60). A selected time interval has been preset to internal counters (142, 146, 154) and corrected for circuit propagation delay times having the same order of magnitude as the desired high resolution. Internal system clock pulses (32, 34) count down the counters to generate an internal pulse delayed by an interval which is functionally related to the preset time interval. A second LCD (184) corrects the internal signal with the high resolution time delay. A second internal pulse is then applied to a third LCD (74) to generate a second set of synchronizing data (76) which is complementary with the first set of synchronizing data (60) for presentation to logic circuits (64). The logic circuits (64) further delay the internal output signal (72) to obtain a proper phase relationship of an output signal (80) with the internal pulses (32, 34). The final delayed output signal (80) thereafter enables the output pulse generator (82) to produce the desired output pulse (84) at the preset time delay interval following input of the trigger pulse (10, 12).

  3. High-resolution electron microscope

    NASA Technical Reports Server (NTRS)

    Nathan, R.

    1977-01-01

    Employing scanning transmission electron microscope as interferometer, relative phases of diffraction maximums can be determined by analysis of dark field images. Synthetic aperture technique and Fourier-transform computer processing of amplitude and phase information provide high resolution images at approximately one angstrom.

  4. Advanced very high resolution radiometer

    NASA Technical Reports Server (NTRS)

    1976-01-01

    The advanced very high resolution radiometer development program is considered. The program covered the design, construction, and test of a breadboard model, engineering model, protoflight model, mechanical structural model, and a life test model. Special bench test and calibration equipment was also developed for use on the program.

  5. High Resolution Orientation Imaging Microscopy

    DTIC Science & Technology

    2012-05-02

    Functions, ICCES 2010, Las Vegas. 17. David Fullwood, Brent Adams, Mike Miles, Stuart Rogers, Ali Khosravani, Raj Mishra, Design for Ductility : Defect... Pseudo -Symmetries by High Resolution EBSD Methods, MS&T. 2009: Pittsburgh. 27. Oliver Johnson, Calvin Gardner, David Fullwood, Brent Adams, George...applied to strain measurements ................................... 6 2.3 Recovery of Lattice Tetragonality and Pseudo -Symmetry Resolution

  6. Assessment of trabecular bone yield and post-yield behavior from high-resolution MRI-based nonlinear finite-element analysis at the distal radius of pre- and postmenopausal women susceptible to osteoporosis

    PubMed Central

    Zhang, Ning; Magland, Jeremy F.; Rajapakse, Chamith S.; Lam, ShingChun Benny

    2013-01-01

    Rationale and Objectives To assess the performance of a nonlinear micro-finite element model on predicting trabecular bone (TB) yield and post-yield behavior based on high-resolution in-vivo MR images via the serial reproducibility. Materials and Methods The nonlinear model captures material nonlinearity by iteratively adjusting tissue-level modulus based on tissue-level effective strain. It enables simulations of TB yield and post-yield behavior from micro-MR images at in-vivo resolution by solving a series of nonlinear systems via an iterative algorithm on a desktop computer. Measures of mechanical competence (yield strain/strength, ultimate strain/strength, modulus of resilience and toughness) were estimated at the distal radius of pre- and postmenopausal women (N=20; age 50–75) in whom osteoporotic fractures typically occur. Each subject underwent three scans (20.2±14.5 days). Serial reproducibility was evaluated via coefficients of variation (CV) and intra-class correlation coefficient (ICC). Results Nonlinear simulations were completed in an average of 14 minutes per 3D image data set involving analysis of 61 strain levels. The predicted yield strain/strength, ultimate strain/strength, modulus of resilience and toughness had a mean value of 0.78%, 3.09 MPa, 1.35%, 3.48 MPa, 14.30 kPa and 32.66 kPa, respectively, covering a substantial range by a factor of up to four. ICC ranged from 0.986 to 0.994 (average 0.991); CV ranged from 1.01% to 5.62% (average 3.6%), with yield strain and toughness having the lowest and highest CV values, respectively. Conclusion The data suggest that the yield and post-yield parameters have adequate reproducibility to evaluate treatment effects in interventional studies within short follow-up periods. PMID:24200486

  7. Benign paroxysmal positional vertigo after surgical drilling of the temporal bone.

    PubMed

    Park, Su-Kyoung; Kim, So Young; Han, Kyu-Hee; Hong, Sung Kwang; Kim, Ji Soo; Koo, Ja-Won

    2013-10-01

    To present the clinical characteristics of secondary BPPV after surgical drilling of the temporal bone. Retrospective study. Tertiary referral academic medical center. Ten patients who developed BPPV after surgical procedure of temporal bone drilling were identified from 965 subjects who underwent surgical drilling of the temporal bone at Seoul National University Bundang Hospital. The localization and lateralization of BPPV were based on positional test using video eye movement recording system and videonystagmography. Onset of BPPV after surgery, distributions of involved semicircular canals, response to particle repositioning maneuver and factors that may influence the development of secondary BPPV after surgical drilling of the temporal bone. Onset of positional vertigo was mostly within 3 days except 1 case (sixth postoperative day). Postoperative BPPV was usually in the contralateral ear in 9 cases (90%), which occurred predominantly on the contralateral horizontal canal in 8 patients (80%). Positional vertigo was resolved after repositioning maneuvers in every case. None of them showed aggravation of bone conduction threshold. The incidence of BPPV after surgical drilling of the temporal bone was around 1%, and the horizontal semicircular canal of the contralateral ear was predominantly involved. Head position during surgery (head restriction to contralateral ear down) as well as limitation of head movement due to compressive mastoid bandage after surgery seems to be responsible for such predominance.

  8. Chondroblastoma of the Temporal Bone: A Case Series, Review, and Suggested Management Strategy

    PubMed Central

    Reid, Luke B.; Wong, David S.; Lyons, Bernard

    2011-01-01

    Chondroblastoma of the temporal bone is a rare condition. Chondroblastomas account for less than 1% of primary bone tumors, and those involving the temporal bone represent a tiny fraction of these tumors with most arising from the knee, rib, and pelvis. We present a case series of two patients who presented with chondroblastomas of the temporal bone over a period of 8 years to the St. Vincent's Hospital in Melbourne, Victoria, Australia. In particular, we outline the presenting complaint, diagnostic imaging undertaken, and the importance of preoperative histopathology in coming to the diagnosis and subsequent resection undertaken. A review of the current literature is presented with a suggested management strategy for these tumors. PMID:23984206

  9. A computerized tomography study of the morphological interrelationship between the temporal bones and the craniofacial complex

    PubMed Central

    Costa, Helder Nunes; Slavicek, Rudolf; Sato, Sadao

    2012-01-01

    The hypothesis that the temporal bones are at the center of the dynamics of the craniofacial complex, directly influencing facial morphology, has been put forward long ago. This study examines the role of the spatial positioning of temporal bones (frontal and sagittal inclination) in terms of influencing overall facial morphology. Several 3D linear, angular and orthogonal measurements obtained through computerized analysis of virtual models of 163 modern human skulls reconstructed from cone-beam computed tomography images were analyzed and correlated. Additionally, the sample was divided into two subgroups based on the median value of temporal bone sagittal inclination [anterior rotation group (n = 82); posterior rotation group (n = 81)], and differences between groups evaluated. Correlation coefficients showed that sagittal inclination of the temporal bone was significantly (P < 0.01) related to midline flexion, transversal width and anterior–posterior length of the basicranium, to the anterior–posterior positioning of the mandible and maxilla, and posterior midfacial height. Frontal inclination of the temporal bone was significantly related (P < 0.01) to basicranium anterior–posterior and transversal dimensions, and to posterior midfacial height. In comparison with the posterior rotation group, the anterior rotation group presented a less flexed and anterior–posteriorly longer cranial base, a narrower skull, porion and the articular eminence located more superiorly and posteriorly, a shorter posterior midfacial height, the palatal plane rotated clockwise, a more retrognathic maxilla and mandible, and the upper posterior occlusal plane more inclined and posteriorly located. The results suggest that differences in craniofacial morphology are highly integrated with differences in the positional relationship of the temporal bones. The sagittal inclination of the temporal bone seems to have a greater impact on the 3D morphology of the craniofacial complex than

  10. Enhancing Realism of Wet Surfaces in Temporal Bone Surgical Simulation

    PubMed Central

    Kerwin, Thomas; Shen, Han-Wei; Stredney, Don

    2009-01-01

    We present techniques to improve visual realism in an interactive surgical simulation application: a mastoidectomy simulator that offers a training environment for medical residents as a complement to using a cadaver. As well as displaying the mastoid bone through volume rendering, the simulation allows users to experience haptic feedback and appropriate sound cues while controlling a virtual bone drill and suction/irrigation device. The techniques employed to improve realism consist of a fluid simulator and a shading model. The former allows for deformable boundaries based on volumetric bone data, while the latter gives a wet look to the rendered bone to emulate more closely the appearance of the bone in a surgical environment. The fluid rendering includes bleeding effects, meniscus rendering, and refraction. We incorporate a planar computational fluid dynamics simulation into our three-dimensional rendering to effect realistic blood diffusion. Maintaining real-time performance while drilling away bone in the simulation is critical for engagement with the system. PMID:19590102

  11. High-Resolution Radar Imaging

    DTIC Science & Technology

    1990-01-14

    vThe goal of this project is to formulate and investigate new approaches for forming images of radar targets from spotlight-mode, delay-doppler...the new methods we are studying. There are two modules in the program. The first module produces simulated radar back-scatter data. The simulation...gives the model and fundamental estimation equations for the method we are developing. The abstract is: "A new approach to high resolution radar

  12. Evaluation of a haptics-based virtual reality temporal bone simulator for anatomy and surgery training.

    PubMed

    Fang, Te-Yung; Wang, Pa-Chun; Liu, Chih-Hsien; Su, Mu-Chun; Yeh, Shih-Ching

    2014-02-01

    Virtual reality simulation training may improve knowledge of anatomy and surgical skills. We evaluated a 3-dimensional, haptic, virtual reality temporal bone simulator for dissection training. The subjects were 7 otolaryngology residents (3 training sessions each) and 7 medical students (1 training session each). The virtual reality temporal bone simulation station included a computer with software that was linked to a force-feedback hand stylus, and the system recorded performance and collisions with vital anatomic structures. Subjects performed virtual reality dissections and completed questionnaires after the training sessions. Residents and students had favorable responses to most questions of the technology acceptance model (TAM) questionnaire. The average TAM scores were above neutral for residents and medical students in all domains, and the average TAM score for residents was significantly higher for the usefulness domain and lower for the playful domain than students. The average satisfaction questionnaire for residents showed that residents had greater overall satisfaction with cadaver temporal bone dissection training than training with the virtual reality simulator or plastic temporal bone. For medical students, the average comprehension score was significantly increased from before to after training for all anatomic structures. Medical students had significantly more collisions with the dura than residents. The residents had similar mean performance scores after the first and third training sessions for all dissection procedures. The virtual reality temporal bone simulator provided satisfactory training for otolaryngology residents and medical students. Copyright © 2013. Published by Elsevier Ireland Ltd.

  13. Evaluating the Effect of Virtual Reality Temporal Bone Simulation on Mastoidectomy Performance: A Meta-analysis.

    PubMed

    Lui, Justin T; Hoy, Monica Y

    2017-06-01

    Background The increasing prevalence of virtual reality simulation in temporal bone surgery warrants an investigation to assess training effectiveness. Objectives To determine if temporal bone simulator use improves mastoidectomy performance. Data Sources Ovid Medline, Embase, and PubMed databases were systematically searched per the PRISMA guidelines. Review Methods Inclusion criteria were peer-reviewed publications that utilized quantitative data of mastoidectomy performance following the use of a temporal bone simulator. The search was restricted to human studies published in English. Studies were excluded if they were in non-peer-reviewed format, were descriptive in nature, or failed to provide surgical performance outcomes. Meta-analysis calculations were then performed. Results A meta-analysis based on the random-effects model revealed an improvement in overall mastoidectomy performance following training on the temporal bone simulator. A standardized mean difference of 0.87 (95% CI, 0.38-1.35) was generated in the setting of a heterogeneous study population ( I(2) = 64.3%, P < .006). Conclusion In the context of a diverse population of virtual reality simulation temporal bone surgery studies, meta-analysis calculations demonstrate an improvement in trainee mastoidectomy performance with virtual simulation training.

  14. CT findings of the temporal bone in CHARGE syndrome: aspects of importance in cochlear implant surgery.

    PubMed

    Vesseur, A C; Verbist, B M; Westerlaan, H E; Kloostra, F J J; Admiraal, R J C; van Ravenswaaij-Arts, C M A; Free, R H; Mylanus, E A M

    2016-12-01

    To provide an overview of anomalies of the temporal bone in CHARGE syndrome relevant to cochlear implantation (CI), anatomical structures of the temporal bone and the respective genotypes were analysed. In this retrospective study, 42 CTs of the temporal bone of 42 patients with CHARGE syndrome were reviewed in consensus by two head-and-neck radiologists and two otological surgeons. Anatomical structures of the temporal bone were evaluated and correlated with genetic data. Abnormalities that might affect CI surgery were seen, such as a vascular structure, a petrosquamosal sinus (13 %), an underdeveloped mastoid (8 %) and an aberrant course of the facial nerve crossing the round window (9 %) and/or the promontory (18 %). The appearance of the inner ear varied widely: in 77 % of patients all semicircular canals were absent and the cochlea varied from normal to hypoplastic. A stenotic cochlear aperture was observed in 37 %. The middle ear was often affected with a stenotic round (14 %) or oval window (71 %). More anomalies were observed in patients with truncating mutations than with non-truncating mutations. Temporal bone findings in CHARGE syndrome vary widely. Vascular variants, aberrant route of the facial nerve, an underdeveloped mastoid, aplasia of the semicircular canals, and stenotic round window may complicate cochlear implantation.

  15. Temporal Bone Osteomyelitis: The Relationship with Malignant Otitis Externa, the Diagnostic Dilemma, and Changing Trends

    PubMed Central

    Chen, Jia-Cheng; Yeh, Chien-Fu; Shiao, An-Suey; Tu, Tzong-Yang

    2014-01-01

    Fifty-five patients hospitalized for osteomyelitis of the temporal bone between 1990 and 2011 were divided into two study groups: group 1 was patients collected from 1990 to 2001 and group 2 was composed of patients between 2002 and 2011. Clinical diagnostic criteria and epidemiologic data were analyzed to illustrate the altering features of osteomyelitis of the temporal bone. Group 1 patients were characterized by high prevalence of diabetes and more commonly suffered from otalgia, otitis externa and granulation tissue in the external auditory canal and higher positive culture for Pseudomonas aeruginosa. Noticeable changing trends were found between both groups, including declining prevalence of diabetes, fewer patients complaining of pain or presenting with otitis externa, and canal granulation, and increased variety of pathogens in group 2. We should highlight the index of clinical suspicion for osteomyelitis of the temporal bone, even in nondiabetic or immunocompetent patients. Painless otorrhea patients were also at risk of osteomyelitis of the temporal bone, especially patients with previous otologic operation. Increased multiplicity of pathogens amplified the difficulty of diagnosis for osteomyelitis of the temporal bone. PMID:24963511

  16. Temporal bone osteomyelitis: the relationship with malignant otitis externa, the diagnostic dilemma, and changing trends.

    PubMed

    Chen, Jia-Cheng; Yeh, Chien-Fu; Shiao, An-Suey; Tu, Tzong-Yang

    2014-01-01

    Fifty-five patients hospitalized for osteomyelitis of the temporal bone between 1990 and 2011 were divided into two study groups: group 1 was patients collected from 1990 to 2001 and group 2 was composed of patients between 2002 and 2011. Clinical diagnostic criteria and epidemiologic data were analyzed to illustrate the altering features of osteomyelitis of the temporal bone. Group 1 patients were characterized by high prevalence of diabetes and more commonly suffered from otalgia, otitis externa and granulation tissue in the external auditory canal and higher positive culture for Pseudomonas aeruginosa. Noticeable changing trends were found between both groups, including declining prevalence of diabetes, fewer patients complaining of pain or presenting with otitis externa, and canal granulation, and increased variety of pathogens in group 2. We should highlight the index of clinical suspicion for osteomyelitis of the temporal bone, even in nondiabetic or immunocompetent patients. Painless otorrhea patients were also at risk of osteomyelitis of the temporal bone, especially patients with previous otologic operation. Increased multiplicity of pathogens amplified the difficulty of diagnosis for osteomyelitis of the temporal bone.

  17. Lack of Evidence for Nonotosclerotic Stapes Fixation in Human Temporal Bone Histopathology

    PubMed Central

    Quesnel, Alicia M.; Ishai, Reuven; Cureoglu, Sebahattin; Linthicum, Fred; Lopez, Ivan A.; Nadol, Joseph B.; McKenna, Michael J.

    2016-01-01

    Hypothesis Nonotosclerotic stapes fixation does not represent a significant cause of stapes ankylosis in patients undergoing stapedectomy; the vast majority have otosclerosis. Background Nonotosclerotic stapes fixation has been proposed as the diagnosis in 30 to 40% of patients undergoing stapedectomy (after excluding rare congenital, systemic, and syndromic causes of stapes fixation and tympanosclerosis). This finding was based on the histopathologic evaluation of total stapedectomy surgical specimens. Since these specimens do not include the surrounding otic capsule, the histopathologic evidence of otosclerosis may be missed. Methods Human temporal bone specimens from patients who underwent stapes mobilization, stapedotomy, or stapedectomy during life were evaluated for histologic evidence of otosclerosis. Cases with a history of temporal bone trauma, tympanosclerosis, and congenital, systemic, or syndromic causes of stapes fixation were excluded. Therefore most temporal bone donors carried a clinical diagnosis of otosclerosis. Results Two hundred and ten specimens from three temporal bone collections were independently evaluated. Otosclerosis was found on histology in 99% (207/210). Therefore, the incidence of nonotosclerotic stapes fixation was 1% (3/210). In 2 of the 3 cases that did not have otosclerosis, the contralateral temporal bone had otosclerosis on histopathologic evaluation. These cases may have had otosclerosis in the footplate only (which was removed at the time of surgery and not available for review). Conclusion Nonotosclerotic stapes fixation is not likely a distinct pathologic classification from otosclerosis. Most patients diagnosed with nonotosclerotic stapes fixation likely have otosclerosis, but do not have otosclerotic foci in the stapes itself. PMID:26905821

  18. Bilateral Facial Paralysis Caused by Bilateral Temporal Bone Fracture: A Case Report and a Literature Review

    PubMed Central

    Eliçora, Sultan Şevik; Dinç, Aykut Erdem; Bişkin, Sultan; Damar, Murat; Bilgin, Ergin

    2015-01-01

    Bilateral facial paralysis caused by bilateral temporal bone fracture is a rare clinical entity, with seven cases reported in the literature to date. In this paper, we describe a 40-year-old male patient with bilateral facial paralysis and hearing loss that developed after an occupational accident. On physical examination, House-Brackmann (HB) facial paralysis of grade 6 was observed on the right side and HB grade 5 paralysis on the left. Upon temporal bone computed tomography (CT) examination, a fracture line exhibiting transverse progression was observed in both petrous temporal bones. Our patient underwent transmastoid facial decompression surgery of the right ear. The patient refused a left-side operation. Such patients require extensive monitoring in intensive care units because the presence of multiple injuries means that facial functions are often very difficult to evaluate. Therefore, delays may ensue in both diagnosis and treatment of bilateral facial paralysis. PMID:26175920

  19. Bilateral Facial Paralysis Caused by Bilateral Temporal Bone Fracture: A Case Report and a Literature Review.

    PubMed

    Eliçora, Sultan Şevik; Dinç, Aykut Erdem; Bişkin, Sultan; Damar, Murat; Bilgin, Ergin

    2015-01-01

    Bilateral facial paralysis caused by bilateral temporal bone fracture is a rare clinical entity, with seven cases reported in the literature to date. In this paper, we describe a 40-year-old male patient with bilateral facial paralysis and hearing loss that developed after an occupational accident. On physical examination, House-Brackmann (HB) facial paralysis of grade 6 was observed on the right side and HB grade 5 paralysis on the left. Upon temporal bone computed tomography (CT) examination, a fracture line exhibiting transverse progression was observed in both petrous temporal bones. Our patient underwent transmastoid facial decompression surgery of the right ear. The patient refused a left-side operation. Such patients require extensive monitoring in intensive care units because the presence of multiple injuries means that facial functions are often very difficult to evaluate. Therefore, delays may ensue in both diagnosis and treatment of bilateral facial paralysis.

  20. Diagnostic Challenges in a Case of IgG4-RD Affecting the Temporal Bone.

    PubMed

    Vuncannon, Jackson Ross; Panella, Nicholas John; Magliocca, Kelly R; Mattox, Douglas E

    2017-03-01

    Immunoglobulin G4-related disease (IgG4-RD) is a recently described fibroinflammatory condition with a characteristic histology. While IgG4-RD can affect a great variety of anatomical sites, it has been seldom described in the temporal bone. Herein, a case IgG4-RD occurring in the temporal bone of a 35-year-old woman is reported. This case of IgG4-RD of the temporal bone proved a uniquely challenging diagnosis due to slightly atypical histology falling outside of "highly suggestive" criteria. We suggest that IgG4-RD remains a challenging diagnosis to reach despite increased awareness of the condition. We further suggest that clinicopathologic correlation remain the cornerstone of diagnosis as the spectrum of presentations of this newly described disease may be wider than previously anticipated.

  1. High Resolution Scanning Reflectarray Antenna

    NASA Technical Reports Server (NTRS)

    Romanofsky, Robert R. (Inventor); Miranda, Felix A. (Inventor)

    2000-01-01

    The present invention provides a High Resolution Scanning Reflectarray Antenna (HRSRA) for the purpose of tracking ground terminals and space craft communication applications. The present invention provides an alternative to using gimbaled parabolic dish antennas and direct radiating phased arrays. When compared to a gimbaled parabolic dish, the HRSRA offers the advantages of vibration free steering without incurring appreciable cost or prime power penalties. In addition, it offers full beam steering at a fraction of the cost of direct radiating arrays and is more efficient.

  2. High-resolution multiphoton cryomicroscopy.

    PubMed

    König, Karsten; Uchugonova, Aisada; Breunig, Hans Georg

    2014-03-15

    An ultracompact high-resolution multiphoton cryomicroscope with a femtosecond near infrared fiber laser has been utilized to study the cellular autofluorescence during freezing and thawing of cells. Cooling resulted in an increase of the intracellular fluorescence intensity followed by morphological modifications at temperatures below -10 °C, depending on the application of the cryoprotectant DMSO and the cooling rate. Furthermore, fluorescence lifetime imaging revealed an increase of the mean lifetime with a decrease in temperature. Non-destructive, label-free optical biopsies of biomaterial in ice can be obtained with sub-20 mW mean powers.

  3. Migration of bone marrow stromal cells in 3D: 4 color methodology reveals spatially and temporally coordinated events.

    PubMed

    Thibault, Marc M; Buschmann, Michael D

    2006-12-01

    The cytoskeleton plays a central role in many cell processes including directed cell migration. Since most previous work has investigated cell migration in two dimensions (2D), new methods are required to study movement in three dimensions (3D) while preserving 3D structure of the cytoskeleton. Most previous studies have labeled two cytoskeletal networks simultaneously, impeding an appreciation of their complex and dynamic interconnections. Here we report the development of a 4 color method to simultaneously image vimentin, actin, tubulin and the nucleus for high-resolution confocal microscopy of bone-marrow stromal cells (BMSCs) migrating through a porous membrane. Several methods were tested for structural preservation and labeling intensity resulting in identification of an optimized simultaneous fixation and permeabilization method using glutaraldehyde, paraformaldehyde and Triton X-100 followed by a quadruple fluorescent labeling method. This procedure was then applied at a sequence of time points to migrating cells, allowing temporal progression of migration to be assessed by visualizing all three networks plus the nucleus, providing new insights into 3D directed cell migration including processes such as leading edge structure, cytoskeletal distribution and nucleokinesis. Colocalization of actin and microtubules with distinct spatial arrangements at the cellular leading edge during migration, together with microtubule axial polarization supports recent reports indicating the pivotal role of microtubules in directed cell migration. This study also provides a foundation for 3D migration studies versus 2D studies, providing precise and robust methods to attain new insights into the cellular mechanisms of motility.

  4. Temporal Changes of Microarchitectural and Mechanical Parameters of Cancellous Bone in the Osteoporotic Rabbit

    PubMed Central

    Wen, Xin-Xin; Xu, Chao; Wang, Fa-Qi; Feng, Ya-Fei; Zhao, Xiong; Yan, Ya-Bo; Lei, Wei

    2015-01-01

    This study was aimed at elucidating the temporal changes of microarchitectural and mechanical parameters of cancellous bone in the osteoporotic rabbit model induced by ovariectomy (OVX) combined with glucocorticoid (GC) administration. Osteoporotic (OP) group received bilateral OVX combined with injections of GC, while sham group only received sham operation. Cancellous bone quality in vertebrae and femoral condyles in each group was assessed by DXA, μCT, nanoindentation, and biomechanical tests at pre-OVX and 4, 6, and 8 weeks after injection. With regard to femoral condyles, nanoindentation test could detect significant decline in tissue modulus and hardness at 4 weeks. However, BMD and microarchitecture of femoral condylar cancellous bone changed significantly at 6 weeks. In vertebrae, BMD, microarchitecture, nanoindentation, and biomechanical tests changed significantly at 4 weeks. Our data demonstrated that temporal changes of microarchitectural and mechanical parameters of cancellous bone in the osteoporotic rabbit were significant. The temporal changes of cancellous bone in different anatomical sites might be different. The nanoindentation method could detect the changes of bone quality at an earlier stage at both femoral condyle and vertebra in the osteoporotic rabbit model than other methods (μCT, BMD). PMID:25918705

  5. Temporal bone fracture following blunt trauma caused by a flying fish.

    PubMed

    Goldenberg, D; Karam, M; Danino, J; Flax-Goldenberg, R; Joachims, H Z

    1998-10-01

    Blunt trauma to the temporal region can cause fracture of the skull base, loss of hearing, vestibular symptoms and otorrhoea. The most common causes of blunt trauma to the ear and surrounding area are motor vehicle accidents, violent encounters, and sports-related accidents. We present an obscure case of a man who was struck in the ear by a flying fish while wading in the sea with resulting temporal bone fracture, sudden deafness, vertigo, cerebrospinal fluid otorrhoea, and pneumocephalus.

  6. A High Resolution CCD Multiplexer

    NASA Astrophysics Data System (ADS)

    Sheu, Larry S.; Kadekod i, Narayan; Nugroho, Yohanes; Lo, Mike; Mortz, Margaret; Ibrahim, Ali

    1983-11-01

    This paper describes a high resolution CCD multiplexer for focal plane imaging systems. The multiplexer incorporates quadrilinear readout registers to achieve two times the resolution of conventional bilinear structure while using the same design rules. Complete parallel charge transfer are ensured by a novel buried channel poly gate isolation scheme. A monolithic silicon photodiode array of 8 Am pitch, 3533 elements was designed with the multi-plexer. Video preprocessing circuits of high speed four to one channel stitching, compensated sample and hold and bad pixel deletion were integrated on chip for improved performance. The modulation transfer functions due to the geometry and the transfer inefficiency are discussed. The theoretically calculated total MTF agrees with the experimental result. At Nyquist frequency of 62.5 c/mm the total MTF is better than 0.6 in the absence of the diffusion MTF degradation. The noise spectrum of the CCD and the output amplifier are presented. The RMS noise of the CCD in dark is approximately 0.35 my over 1 MHz bandwidth. The CCD noise increases with light input attributed primarily to the shot noise. The low noise nature of the multiplexer makes it ideal for the high resolution low light level detection applications.

  7. Validation of Exposure Visualization and Audible Distance Emission for Navigated Temporal Bone Drilling in Phantoms

    PubMed Central

    Voormolen, Eduard H. J.; Woerdeman, Peter A.; van Stralen, Marijn; Noordmans, Herke Jan; Viergever, Max A.; Regli, Luca; van der Sprenkel, Jan Willem Berkelbach

    2012-01-01

    Background A neuronavigation interface with extended function as compared with current systems was developed to aid during temporal bone surgery. The interface, named EVADE, updates the prior anatomical image and visualizes the bone drilling process virtually in real-time without need for intra-operative imaging. Furthermore, EVADE continuously calculates the distance from the drill tip to segmented temporal bone critical structures (e.g. the sigmoid sinus and facial nerve) and produces audiovisual warnings if the surgeon drills in too close vicinity. The aim of this study was to evaluate the accuracy and surgical utility of EVADE in physical phantoms. Methodology/Principal Findings We performed 228 measurements assessing the position accuracy of tracking a navigated drill in the operating theatre. A mean target registration error of 1.33±0.61 mm with a maximum error of 3.04 mm was found. Five neurosurgeons each drilled two temporal bone phantoms, once using EVADE, and once using a standard neuronavigation interface. While using standard neuronavigation the surgeons damaged three modeled temporal bone critical structures. No structure was hit by surgeons utilizing EVADE. Surgeons felt better orientated and thought they had improved tumor exposure with EVADE. Furthermore, we compared the distances between surface meshes of the virtual drill cavities created by EVADE to actual drill cavities: average maximum errors of 2.54±0.49 mm and −2.70±0.48 mm were found. Conclusions/Significance These results demonstrate that EVADE gives accurate feedback which reduces risks of harming modeled critical structures compared to a standard neuronavigation interface during temporal bone phantom drilling. PMID:22848452

  8. Enhanced High Resolution RBS System

    SciTech Connect

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 A ring TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron registered accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  9. Enhanced High Resolution RBS System

    NASA Astrophysics Data System (ADS)

    Pollock, Thomas J.; Hass, James A.; Klody, George M.

    2011-06-01

    Improvements in full spectrum resolution with the second NEC high resolution RBS system are summarized. Results for 50 Å TiN/HfO films on Si yielding energy resolution on the order of 1 keV are also presented. Detector enhancements include improved pulse processing electronics, upgraded shielding for the MCP/RAE detector, and reduced noise generated from pumping. Energy resolution measurements on spectra front edge coupled with calculations using 0.4mStr solid angle show that beam energy spread at 400 KeV from the Pelletron® accelerator is less than 100 eV. To improve user throughput, magnet control has been added to the automatic data collection. Depth profiles derived from experimental data are discussed. For the thin films profiled, depth resolutions were on the Angstrom level with the non-linear energy/channel conversions ranging from 100 to 200 eV.

  10. High-resolution land topography

    NASA Astrophysics Data System (ADS)

    Massonnet, Didier; Elachi, Charles

    2006-11-01

    After a description of the background, methods of production and some scientific uses of high-resolution land topography, we present the current status and the prospect of radar interferometry, regarded as one of the best techniques for obtaining the most global and the most accurate topographic maps. After introducing briefly the theoretical aspects of radar interferometry - principles, limits of operation and various capabilities -, we will focus on the topographic applications that resulted in an almost global topographic map of the earth: the SRTM map. After introducing the Interferometric Cartwheel system, we will build on its expected performances to discuss the scientific prospects of refining a global topographic map to sub-metric accuracy. We also show how other fields of sciences such as hydrology may benefit from the products generated by interferometric radar systems. To cite this article: D. Massonnet, C. Elachi, C. R. Geoscience 338 (2006).

  11. HIRAS, high resolution IRAS images

    NASA Astrophysics Data System (ADS)

    Bontekoe, Tj. R.; Kester, D. J. M.; Wesselius, P. R.

    The IRAS Software Telescope allows everyone to obtain the state-of-the-art IRAS products (survey, pointed observations, as well as low-resolution spectra) from raw uncalibrated scan data to FITS maps and any stage in between, any size area up to five by five degree, within 24 hours response time, and without the tedious proposal and refereeing process. This is done via an electronic mail server, without manual interaction. High Resolution Images can also be made by running HIRAS, which drives the MemSys5 (Gull & Skilling 1991) maximum entropy package. Herewith a resolution of order one arc-minute, instead of the usual five arc-minutes, can be obtained.

  12. High-resolution interferometric spectrophotopolarimetry

    NASA Technical Reports Server (NTRS)

    Fymat, A. L.

    1981-01-01

    Spectrophotopolarimetric capability can be added to a laboratory interferometer-spectrometer by use of a specially designed module described herein. With the instrument so augmented, high-resolution spectra can be obtained of the Stokes parameters of the reference beam and the beams diffusely reflected or transmitted by a sample medium of interest. For any such beam, the exponential Fourier transforms of the two interferograms obtained with a polarizer-analyzer oriented along the 0 deg and the 90 deg directions provide the spectra of I and Q, separately. Within experimental (and numerical) noise, this I spectrum should be the same as the one obtained with the polarizer removed. The remaining Stokes parameters U and V are obtained with a third interferogram recorded with the polarizer along the 45 deg direction. The complete theory of this instrument is described including the detailed analysis of the polarization-interferograms it provides.

  13. High Resolution Thermometry for EXACT

    NASA Technical Reports Server (NTRS)

    Panek, J. S.; Nash, A. E.; Larson, M.; Mulders, N.

    2000-01-01

    High Resolution Thermometers (HRTs) based on SQUID detection of the magnetization of a paramagnetic salt or a metal alloy has been commonly used for sub-nano Kelvin temperature resolution in low temperature physics experiments. The main applications to date have been for temperature ranges near the lambda point of He-4 (2.177 K). These thermometers made use of materials such as Cu(NH4)2Br4 *2H2O, GdCl3, or PdFe. None of these materials are suitable for EXACT, which will explore the region of the He-3/He-4 tricritical point at 0.87 K. The experiment requirements and properties of several candidate paramagnetic materials will be presented, as well as preliminary test results.

  14. HRSC: High resolution stereo camera

    USGS Publications Warehouse

    Neukum, G.; Jaumann, R.; Basilevsky, A.T.; Dumke, A.; Van Gasselt, S.; Giese, B.; Hauber, E.; Head, J. W.; Heipke, C.; Hoekzema, N.; Hoffmann, H.; Greeley, R.; Gwinner, K.; Kirk, R.; Markiewicz, W.; McCord, T.B.; Michael, G.; Muller, Jan-Peter; Murray, J.B.; Oberst, J.; Pinet, P.; Pischel, R.; Roatsch, T.; Scholten, F.; Willner, K.

    2009-01-01

    The High Resolution Stereo Camera (HRSC) on Mars Express has delivered a wealth of image data, amounting to over 2.5 TB from the start of the mapping phase in January 2004 to September 2008. In that time, more than a third of Mars was covered at a resolution of 10-20 m/pixel in stereo and colour. After five years in orbit, HRSC is still in excellent shape, and it could continue to operate for many more years. HRSC has proven its ability to close the gap between the low-resolution Viking image data and the high-resolution Mars Orbiter Camera images, leading to a global picture of the geological evolution of Mars that is now much clearer than ever before. Derived highest-resolution terrain model data have closed major gaps and provided an unprecedented insight into the shape of the surface, which is paramount not only for surface analysis and geological interpretation, but also for combination with and analysis of data from other instruments, as well as in planning for future missions. This chapter presents the scientific output from data analysis and highlevel data processing, complemented by a summary of how the experiment is conducted by the HRSC team members working in geoscience, atmospheric science, photogrammetry and spectrophotometry. Many of these contributions have been or will be published in peer-reviewed journals and special issues. They form a cross-section of the scientific output, either by summarising the new geoscientific picture of Mars provided by HRSC or by detailing some of the topics of data analysis concerning photogrammetry, cartography and spectral data analysis.

  15. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-08-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  16. High resolution tomographic instrument development

    SciTech Connect

    Not Available

    1992-01-01

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefited greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  17. High resolution time interval counter

    NASA Technical Reports Server (NTRS)

    Zhang, Victor S.; Davis, Dick D.; Lombardi, Michael A.

    1995-01-01

    In recent years, we have developed two types of high resolution, multi-channel time interval counters. In the NIST two-way time transfer MODEM application, the counter is designed for operating primarily in the interrupt-driven mode, with 3 start channels and 3 stop channels. The intended start and stop signals are 1 PPS, although other frequencies can also be applied to start and stop the count. The time interval counters used in the NIST Frequency Measurement and Analysis System are implemented with 7 start channels and 7 stop channels. Four of the 7 start channels are devoted to the frequencies of 1 MHz, 5 MHz or 10 MHz, while triggering signals to all other start and stop channels can range from 1 PPS to 100 kHz. Time interval interpolation plays a key role in achieving the high resolution time interval measurements for both counters. With a 10 MHz time base, both counters demonstrate a single-shot resolution of better than 40 ps, and a stability of better than 5 x 10(exp -12) (sigma(sub chi)(tau)) after self test of 1000 seconds). The maximum rate of time interval measurements (with no dead time) is 1.0 kHz for the counter used in the MODEM application and is 2.0 kHz for the counter used in the Frequency Measurement and Analysis System. The counters are implemented as plug-in units for an AT-compatible personal computer. This configuration provides an efficient way of using a computer not only to control and operate the counters, but also to store and process measured data.

  18. High resolution tomographic instrument development

    NASA Astrophysics Data System (ADS)

    Our recent work has concentrated on the development of high-resolution PET instrumentation reflecting in part the growing importance of PET in nuclear medicine imaging. We have developed a number of positron imaging instruments and have the distinction that every instrument has been placed in operation and has had an extensive history of application for basic research and clinical study. The present program is a logical continuation of these earlier successes. PCR-I, a single ring positron tomograph was the first demonstration of analog coding using BGO. It employed 4 mm detectors and is currently being used for a wide range of biological studies. These are of immense importance in guiding the direction for future instruments. In particular, PCR-II, a volume sensitive positron tomograph with 3 mm spatial resolution has benefitted greatly from the studies using PCR-I. PCR-II is currently in the final stages of assembly and testing and will shortly be placed in operation for imaging phantoms, animals and ultimately humans. Perhaps the most important finding resulting from our previous study is that resolution and sensitivity must be carefully balanced to achieve a practical high resolution system. PCR-II has been designed to have the detection characteristics required to achieve 3 mm resolution in human brain under practical imaging situations. The development of algorithms by the group headed by Dr. Chesler is based on a long history of prior study including his joint work with Drs. Pelc and Reiderer and Stearns. This body of expertise will be applied to the processing of data from PCR-II when it becomes operational.

  19. Using a virtual reality temporal bone simulator to assess otolaryngology trainees.

    PubMed

    Zirkle, Molly; Roberson, David W; Leuwer, Rudolf; Dubrowski, Adam

    2007-02-01

    The objective of this study is to determine the feasibility of computerized evaluation of resident performance using hand motion analysis on a virtual reality temporal bone (VR TB) simulator. We hypothesized that both computerized analysis and expert ratings would discriminate the performance of novices from experienced trainees. We also hypothesized that performance on the virtual reality temporal bone simulator (VR TB) would differentiate based on previous drilling experience. The authors conducted a randomized, blind assessment study. Nineteen volunteers from the Otolaryngology-Head and Neck Surgery training program at the University of Toronto drilled both a cadaveric TB and a simulated VR TB. Expert reviewers were asked to assess operative readiness of the trainee based on a blind video review of their performance. Computerized hand motion analysis of each participant's performance was conducted. Expert raters were able to discriminate novices from experienced trainees (P < .05) on cadaveric temporal bones, and there was a trend toward discrimination on VR TB performance. Hand motion analysis showed that experienced trainees had better movement economy than novices (P < .05) on the VR TB. Performance, as measured by hand motion analysis on the VR TB simulator, reflects trainees' previous drilling experience. This study suggests that otolaryngology trainees could accomplish initial temporal bone training on a VR TB simulator, which can provide feedback to the trainee, and may reduce the need for constant faculty supervision and evaluation.

  20. Pneumatization of Mastoid Air Cells, Temporal Bone, Ethmoid and Sphenoid Sinuses. Any Correlation?

    PubMed

    Hindi, Khalid; Alazzawi, Sarmad; Raman, Rajagopalan; Prepageran, Narayanan; Rahmat, Kartini

    2014-12-01

    The aim of this study is to assess the pneumatization of the paranasal sinuses (PNS) and other parts of temporal bone such as mastoid air cells and to investigate if there was any association between the aeration of these structures among the three major ethnic groups in Malaysia (Malay, Chinese, Indian) as this would be representative of Asia. A retrospective review of 150 computed tomography (CT) scans of PNS and temporal bones was done and analysed. The pneumatization of each area was obtained and compared using statistical analysis. Patients with a history of previous medical or surgical problems in the intended areas were excluded from the study. The pneumatization of the mastoid air cells and other temporal bone parts were noted to be symmetrical in more than 75 %. There was a positive correlation between the pneumatization of mastoid air cells and that of the sphenoid sinus. The prevalence of Agger nasi, Haller's and Onodi cells was observed to be significantly higher in the Chinese group. Preoperative assessment of the temporal bone and PNS with CT scan may be helpful in the evaluation of their anatomical landmark and decrease the possibility of surgical complications related to 3D structures.

  1. Quantitative analysis of Neanderthal temporal bone morphology using three-dimensional geometric morphometrics.

    PubMed

    Harvati, Katerina

    2003-04-01

    The temporal bone is the location of several traits thought to differentiate Neanderthals from modern humans, including some proposed Neanderthal-derived traits. Most of these, however, are difficult to measure and are usually described qualitatively. This study applied the techniques of geometric morphometrics to the complex morphology of the temporal bone, in order to quantify the differences observed between Neanderthal and modern human anatomy. Two hundred and seventy modern human crania were measured, representing 9 populations of 30 individuals each, and spanning the extremes of the modern human geographical range. Twelve Neanderthal specimens, as well as Reilingen, Kabwe, Skhul 5, Qafzeh 9, and 4 Late Paleolithic European specimens, were included in the fossil sample. The data were collected in the form of three-dimensional (3-D) landmark coordinates, and specimen configurations were superimposed using generalized Procrustes analysis. The fitted coordinates were then analyzed by an array of multivariate statistical methods, including principal components analysis, canonical variates analysis, and Mahalanobis D(2). The temporal bone landmark analysis was very successful in separating Neanderthals from modern humans. Neanderthals were separated from modern humans in both the principal components and canonical variates analyses. They were much further in Mahalanobis distances from all modern human populations than any two modern human groups were from each other. Most of the previously described temporal bone traits contributed to this separation. Copyright 2003 Wiley-Liss, Inc.

  2. Cone beam computed tomography and histological evaluations of a straight electrode array positioning in temporal bones.

    PubMed

    Mosnier, Isabelle; Célérier, Charlotte; Bensimon, Jean-Loup; de Seta, Daniele; Sterkers, Olivier; Nguyen, Yann; Bernardeschi, Daniele

    2017-03-01

    CBCT allows a precise evaluation of the dimensions and of the shape of the cochlear duct that is of primary importance for the choice of the length and the design of the electrode array. This radio-histological study confirms that CBCT is a reliable tool to be used in clinical studies to evaluate the position of straight electrode arrays within the cochlear scala. To validate the reliability of cone beam computed tomography (CBCT) in the evaluation of cochlear anatomy and positioning of a straight electrode array, by comparing radiological images to histological analysis of cochlear implanted temporal bones. Eight temporal bones for four subjects were analysed before and after cochlear implantation with a straight electrode array. The size of the cochlea, the dimensions, and shape of the cochlear duct at 180° and 360° were evaluated on CBCT performed before implantation. Temporal bones then underwent histological analysis to determine the position of the electrode array. Scalar localization of the electrode array was assessed on CBCT performed after implantation, and compared with histological study. CBCT is a reliable radiological technique to differentiate variability not only of cochlear dimensions, but also of size and shape of the cochlea. Histological analysis confirmed the scalar position of the electrode array assessed by the CBCT in 7/8 temporal bones, but soft tissue trauma such as dissection of the spiral ligament was not identified by the CBCT.

  3. Temporal bone osteoradionecrosis after surgery and radiotherapy for malignant parotid tumors.

    PubMed

    Leonetti, John P; Marzo, Sam J; Zender, Chad A; Porter, Ryan G; Melian, Edward

    2010-06-01

    To assess the incidence of osteoradionecrosis (ORN) of the temporal bone after surgery with radiotherapy for malignant parotid tumors. A tertiary care, academic medical center. All patients who underwent surgical resection with postoperative radiotherapy (RT) for a malignant parotid tumor between July 1988 and July 2007. A retrospective chart analysis to determine the extent of surgery, the RT parameters, and the incidence of ORN of the temporal bone. The incidence of ORN in 3 subgroups of patients. The 221 patients with malignant parotid tumors who underwent surgical resection with postoperative RT were divided into groups 1, parotidectomy only; 2, parotidectomy with mastoidectomy; and 3, parotidectomy with subtotal petrosectomy. The overall incidence of temporal bone ORN in group 1 was 2 (2%) of 106; in group 2, 8 (13%) of 64; and in group 3, 0 (0%) of 51. The incidence of temporal bone ORN is higher after mastoidectomy for facial nerve identification or resection in patients undergoing parotidectomy with postoperative radiotherapy. Oversew of the ear canal with mastoid obliteration should be considered in this subgroup of patients to avoid this long-term complication of radiotherapy used in the treatment of malignant parotid tumors.

  4. Technical report: immunofluorescence and TUNEL staining of celloidin embedded human temporal bone tissues.

    PubMed

    Markaryan, Adam; Nelson, Erik G; Tretiakova, Maria; Hinojosa, Raul

    2008-07-01

    The large archival human temporal bone collections of the world have been fixed in formalin and embedded in celloidin. These treatments have created challenges to the use of contemporary probes, which are routinely used in the evaluation of fresh and frozen tissues, for the analysis of archival temporal bone tissues. Formalin alters the configuration of proteins and can obscure antigens by modifying the epitopes recognized by antibodies. Celloidin embedding provides superior support of the delicate membranous structures of the inner ear to maintain tissue integrity during sectioning, however, inadequate removal of celloidin may limit tissue permeability resulting in poor penetration of large molecules. Methods are described in this manuscript that have allowed reproducible immunofluorescence and TUNEL (terminal deoxynucleotidyl transferase mediated dUTP nick end labeling) staining results in these archival tissues. To our knowledge, successful immunofluorescence staining of type I collagen, immunofluorescence staining of cytochrome c oxidase subunit III (COX III), and TUNEL staining in archival human temporal bone tissues with confocal microscopy has not been previously reported. These results demonstrate the utility of developing techniques to evaluate the existing collections of archival temporal bones which remain our greatest source of tissue for investigating the causes of ear diseases.

  5. Epitympanum volume and tympanic isthmus area in temporal bones with retraction pockets.

    PubMed

    Monsanto, Rafael da Costa; Pauna, Henrique Furlan; Kaya, Serdar; Hızlı, Ömer; Kwon, Geeyoun; Paparella, Michael M; Cureoglu, Sebahattin

    2016-11-01

    To compare the volume of the epitympanic space, as well as the area of the tympanic isthmus, in human temporal bones with retraction pockets to those with chronic otitis media without retraction pockets and to those with neither condition. Comparative human temporal bone study. We generated a three-dimensional model of the bony epitympanum and measured the epitympanic space. We also compared the area of the tympanic isthmus. The mean total volume of the epitympanum was 40.55 ± 7.14 mm(3) in the retraction pocket group, 50.03 ± 8.49 mm(3) in the chronic otitis media group, and 48.03 ± 9.16 mm(3) in the neither condition group. The mean volume of the anterior, lateral, and medial compartments in temporal bones in the retraction pocket group was significantly smaller than in the two control groups (P < 0.05). Total epitympanic volume was also significantly smaller in the retraction pocket group than in both control groups (P < 0.05). The mean area of the tympanic isthmus was significantly smaller in the retraction pocket group (8.11 ± 2.44 mm(2) ) than in the chronic otitis media group (9.82 ± 2.06 mm(2) ) or the neither condition group (10.66 ± 1.78 mm(2) ) (P < 0.05). Our data indicate that temporal bones with retraction pockets have a smaller volume bony epitympanum and a smaller tympanic isthmus area as compared with temporal bones from both control groups. The smaller volume tympanic isthmus in the retraction pocket group may suggest that a blockage in the aeration pathways to the epitympanum could create dysventilation, resulting in negative pressure and ultimately in retraction pockets and cholesteatomas. NA Laryngoscope, 126:E369-E374, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  6. Systems-based identification of temporal processing pathways during bone cell mechanotransduction.

    PubMed

    Worton, Leah E; Ausk, Brandon J; Downey, Leah M; Bain, Steven D; Gardiner, Edith M; Srinivasan, Sundar; Gross, Ted S; Kwon, Ronald Y

    2013-01-01

    Bone has long been established to be a highly mechanosensitive tissue. When subjected to mechanical loading, bone exhibits profoundly different anabolic responses depending on the temporal pattern in which the stimulus is applied. This phenomenon has been termed temporal processing, and involves complex signal amplification mechanisms that are largely unidentified. In this study, our goal was to characterize transcriptomic perturbations arising from the insertion of intermittent rest periods (a temporal variation with profound effects on bone anabolism) in osteoblastic cells subjected to fluid flow, and assess the utility of these perturbations to identify signaling pathways that are differentially activated by this temporal variation. At the level of the genome, we found that the common and differential alterations in gene expression arising from the two flow conditions were distributionally distinct, with the differential alterations characterized by many small changes in a large number of genes. Using bioinformatics analysis, we identified distinct up- and down-regulation transcriptomic signatures associated with the insertion of rest intervals, and found that the up-regulation signature was significantly associated with MAPK signaling. Confirming the involvement of the MAPK pathway, we found that the insertion of rest intervals significantly elevated flow-induced p-ERK1/2 levels by enabling a second spike in activity that was not observed in response to continuous flow. Collectively, these studies are the first to characterize distinct transcriptomic perturbations in bone cells subjected to continuous and intermittent stimulation, and directly demonstrate the utility of systems-based transcriptomic analysis to identify novel acute signaling pathways underlying temporal processing in bone cells.

  7. Temporally controlled multiple-gene delivery in scaffolds: A promising strategy to enhance bone regeneration.

    PubMed

    Liu, Jinsong; Xu, Lihua; Li, Yiming; Ma, Jianfeng

    2011-02-01

    Bone defects sometimes require more effective repair regimens than conventional clinical therapies can provide. On account of this, tissue-engineered scaffolds have emerged as a promising alternative. Scaffolds that release genes encoding growth factors (GFs) offer additional benefits for bone regeneration in comparison with scaffolds providing protein delivery. The present gene delivery systems focus on unitary or dual genes delivery without controlled release. In the meantime, evidences indicate that bone formation is a complex cascade of events, in which time-dependent expression of multiple growth factors is involved. In our hypothesis, a temporally controlled, multi-gene delivery system embedded in a scaffold matrix can be fabricated; such a system is capable of mimicking the expression of growth factor profile in osteogenesis. Consequently, bone regeneration can be promoted by sequential gene expression of multiple growth factors.

  8. Integrated High Resolution Monitoring of Mediterranean vegetation

    NASA Astrophysics Data System (ADS)

    Cesaraccio, Carla; Piga, Alessandra; Ventura, Andrea; Arca, Angelo; Duce, Pierpaolo; Mereu, Simone

    2017-04-01

    The study of the vegetation features in a complex and highly vulnerable ecosystems, such as Mediterranean maquis, leads to the need of using continuous monitoring systems at high spatial and temporal resolution, for a better interpretation of the mechanisms of phenological and eco-physiological processes. Near-surface remote sensing techniques are used to quantify, at high temporal resolution, and with a certain degree of spatial integration, the seasonal variations of the surface optical and radiometric properties. In recent decades, the design and implementation of global monitoring networks involved the use of non-destructive and/or cheaper approaches such as (i) continuous surface fluxes measurement stations, (ii) phenological observation networks, and (iii) measurement of temporal and spatial variations of the vegetation spectral properties. In this work preliminary results from the ECO-SCALE (Integrated High Resolution Monitoring of Mediterranean vegetation) project are reported. The project was manly aimed to develop an integrated system for environmental monitoring based on digital photography, hyperspectral radiometry , and micrometeorological techniques during three years of experimentation (2013-2016) in a Mediterranean site of Italy (Capo Caccia, Alghero). The main results concerned the analysis of chromatic coordinates indices from digital images, to characterized the phenological patterns for typical shrubland species, determining start and duration of the growing season, and the physiological status in relation to different environmental drought conditions; then the seasonal patterns of canopy phenology, was compared to NEE (Net Ecosystem Exchange) patterns, showing similarities. However, maximum values of NEE and ER (Ecosystem respiration), and short term variation, seemed mainly tuned by inter annual pattern of meteorological variables, in particular of temperature recorded in the months preceding the vegetation green-up. Finally, green signals

  9. High Resolution Measurement of the Glycolytic Rate

    PubMed Central

    Bittner, Carla X.; Loaiza, Anitsi; Ruminot, Iván; Larenas, Valeria; Sotelo-Hitschfeld, Tamara; Gutiérrez, Robin; Córdova, Alex; Valdebenito, Rocío; Frommer, Wolf B.; Barros, L. Felipe

    2010-01-01

    The glycolytic rate is sensitive to physiological activity, hormones, stress, aging, and malignant transformation. Standard techniques to measure the glycolytic rate are based on radioactive isotopes, are not able to resolve single cells and have poor temporal resolution, limitations that hamper the study of energy metabolism in the brain and other organs. A new method is described in this article, which makes use of a recently developed FRET glucose nanosensor to measure the rate of glycolysis in single cells with high temporal resolution. Used in cultured astrocytes, the method showed for the first time that glycolysis can be activated within seconds by a combination of glutamate and K+, supporting a role for astrocytes in neurometabolic and neurovascular coupling in the brain. It was also possible to make a direct comparison of metabolism in neurons and astrocytes lying in close proximity, paving the way to a high-resolution characterization of brain energy metabolism. Single-cell glycolytic rates were also measured in fibroblasts, adipocytes, myoblasts, and tumor cells, showing higher rates for undifferentiated cells and significant metabolic heterogeneity within cell types. This method should facilitate the investigation of tissue metabolism at the single-cell level and is readily adaptable for high-throughput analysis. PMID:20890447

  10. Long-Term Results of Surgery for Temporal Bone Paraganglioma

    PubMed Central

    Gjuric, Mislav; Seidinger, Lynda; Wigand, Malte Erik

    1996-01-01

    The only way to resolve the dispute about the effectiveness of surgery versus radiation therapy for glomus tympanicum and jugulare tumors is adequate long-term studies. In a retrospective study with an average follow-up period of 15 years (range 11 to 23 years) we reassessed 11 patients with glomus tympanicum tumors and 11 patients with glomus jugulare tumors. Ten of 11 patients with glomus tympanicum tumor were tumor-free after surgery. A temporary facial palsy and an external meatal wall defect were the only surgical complications. The air-bone gap postoperatively closed to within 10 dB in three patients, to within 20 dB in six patients, and to more than 30 dB in one patient. Nine of 10 patients with glomus jugulare tumor receiving complete resection were tumor-free. Less than half the patients experienced new-onset cranial nerve function loss, and all made satisfactory recovery, eliminating the need for tracheostomy or gastrostomy. In two patients, the hearing could be preserved on the preoperative level, but the majority already presented with deafness. In the long-term, surgery remains a treatment of choice for glomus tympanicum tumors. It is also an extremely effective treatment with low morbidity for glomus jugulare tumors, including those with intracranial extension. PMID:17170971

  11. High resolution imaging at Palomar

    NASA Technical Reports Server (NTRS)

    Kulkarni, Shrinivas R.

    1992-01-01

    For the last two years we have embarked on a program of understanding the ultimate limits of ground-based optical imaging. We have designed and fabricated a camera specifically for high resolution imaging. This camera has now been pressed into service at the prime focus of the Hale 5 m telescope. We have concentrated on two techniques: the Non-Redundant Masking (NRM) and Weigelt's Fully Filled Aperture (FFA) method. The former is the optical analog of radio interferometry and the latter is a higher order extension of the Labeyrie autocorrelation method. As in radio Very Long Baseline Interferometry (VLBI), both these techniques essentially measure the closure phase and, hence, true image construction is possible. We have successfully imaged binary stars and asteroids with angular resolution approaching the diffraction limit of the telescope and image quality approaching that of a typical radio VLBI map. In addition, we have carried out analytical and simulation studies to determine the ultimate limits of ground-based optical imaging, the limits of space-based interferometric imaging, and investigated the details of imaging tradeoffs of beam combination in optical interferometers.

  12. High-resolution infrared imaging

    NASA Astrophysics Data System (ADS)

    Falco, Charles M.

    2010-08-01

    The hands and mind of an artist are intimately involved in the creative process of image formation, intrinsically making paintings significantly more complex than photographs to analyze. In spite of this difficulty, several years ago the artist David Hockney and I identified optical evidence within a number of paintings that demonstrated artists began using optical projections as early as c1425 - nearly 175 years before Galileo - as aids for producing portions of their images. In the course of our work, Hockney and I developed insights that I have been applying to a new approach to computerized image analysis. Recently I developed and characterized a portable high resolution infrared for capturing additional information from paintings. Because many pigments are semi-transparent in the IR, in a number of cases IR photographs ("reflectograms") have revealed marks made by the artists that had been hidden under paint ever since they were made. I have used this IR camera to capture photographs ("reflectograms") of hundreds of paintings in over a dozen museums on three continents and, in some cases, these reflectograms have provided new insights into decisions the artists made in creating the final images that we see in the visible.

  13. High resolution auditory perception system

    NASA Astrophysics Data System (ADS)

    Alam, Iftekhar; Ghatol, Ashok

    2005-04-01

    Blindness is a sensory disability which is difficult to treat but can to some extent be helped by artificial aids. The paper describes the design aspects of a high resolution auditory perception system, which is designed on the principle of air sonar with binaural perception. This system is a vision substitution aid for enabling blind persons. The blind person wears ultrasonic eyeglasses which has ultrasonic sensor array embedded on it. The system has been designed to operate in multiresolution modes. The ultrasonic sound from the transmitter array is reflected back by the objects, falling in the beam of the array and is received. The received signal is converted to a sound signal, which is presented stereophonically for auditory perception. A detailed study has been done as the background work required for the system implementation; the appropriate range analysis procedure, analysis of space-time signals, the acoustic sensors study, amplification methods and study of the removal of noise using filters. Finally the system implementation including both the hardware and the software part of it has been described. Experimental results on actual blind subjects and inferences obtained during the study have also been included.

  14. High resolution time interval counter

    DOEpatents

    Condreva, K.J.

    1994-07-26

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured. 3 figs.

  15. High resolution time interval counter

    DOEpatents

    Condreva, Kenneth J.

    1994-01-01

    A high resolution counter circuit measures the time interval between the occurrence of an initial and a subsequent electrical pulse to two nanoseconds resolution using an eight megahertz clock. The circuit includes a main counter for receiving electrical pulses and generating a binary word--a measure of the number of eight megahertz clock pulses occurring between the signals. A pair of first and second pulse stretchers receive the signal and generate a pair of output signals whose widths are approximately sixty-four times the time between the receipt of the signals by the respective pulse stretchers and the receipt by the respective pulse stretchers of a second subsequent clock pulse. Output signals are thereafter supplied to a pair of start and stop counters operable to generate a pair of binary output words representative of the measure of the width of the pulses to a resolution of two nanoseconds. Errors associated with the pulse stretchers are corrected by providing calibration data to both stretcher circuits, and recording start and stop counter values. Stretched initial and subsequent signals are combined with autocalibration data and supplied to an arithmetic logic unit to determine the time interval in nanoseconds between the pair of electrical pulses being measured.

  16. High resolution optoelectronic retinal prosthesis

    NASA Astrophysics Data System (ADS)

    Loudin, Jim; Dinyari, Rostam; Huie, Phil; Butterwick, Alex; Peumans, Peter; Palanker, Daniel

    2009-02-01

    Electronic retinal prostheses seek to restore sight in patients with retinal degeneration by delivering pulsed electric currents to retinal neurons via an array of microelectrodes. Most implants use inductive or optical transmission of information and power to an intraocular receiver, with decoded signals subsequently distributed to retinal electrodes through an intraocular cable. Surgical complexity could be minimized by an "integrated" prosthesis, in which both power and data are delivered directly to the stimulating array without any discrete components or cables. We present here an integrated retinal prosthesis system based on a photodiode array implant. Video frames are processed and imaged onto the retinal implant by a video goggle projection system operating at near-infrared wavelengths (~ 900 nm). Photodiodes convert light into pulsed electric current, with charge injection maximized by specially optimized series photodiode circuits. Prostheses of three different pixel densities (16 pix/mm2, 64 pix/mm2, and 256 pix/mm2) have been designed, simulated, and prototyped. Retinal tissue response to subretinal implants made of various materials has been investigated in RCS rats. The resulting prosthesis can provide sufficient charge injection for high resolution retinal stimulation without the need for implantation of any bulky discrete elements such as coils or tethers. In addition, since every pixel functions independently, pixel arrays may be placed separately in the subretinal space, providing visual stimulation to a larger field of view.

  17. High-Resolution Mass Spectrometers

    NASA Astrophysics Data System (ADS)

    Marshall, Alan G.; Hendrickson, Christopher L.

    2008-07-01

    Over the past decade, mass spectrometry has been revolutionized by access to instruments of increasingly high mass-resolving power. For small molecules up to ˜400 Da (e.g., drugs, metabolites, and various natural organic mixtures ranging from foods to petroleum), it is possible to determine elemental compositions (CcHhNnOoSsPp…) of thousands of chemical components simultaneously from accurate mass measurements (the same can be done up to 1000 Da if additional information is included). At higher mass, it becomes possible to identify proteins (including posttranslational modifications) from proteolytic peptides, as well as lipids, glycoconjugates, and other biological components. At even higher mass (˜100,000 Da or higher), it is possible to characterize posttranslational modifications of intact proteins and to map the binding surfaces of large biomolecule complexes. Here we review the principles and techniques of the highest-resolution analytical mass spectrometers (time-of-flight and Fourier transform ion cyclotron resonance and orbitrap mass analyzers) and describe some representative high-resolution applications.

  18. Clinical features and radiological evaluation of otic capsule sparing temporal bone fractures.

    PubMed

    Song, S W; Jun, B C; Kim, H

    2017-03-01

    To evaluate the clinical and radiological aspects of otic capsule sparing temporal bone fractures. Using medical records, 188 temporal bones of 173 patients with otic capsule sparing temporal bone fractures were evaluated. Otoscopic findings and symptoms, facial paralysis, and hearing loss were assessed. Using regional analysis, 7 fractures were classified as type I, 85 as type II, 169 as type III and 114 as type IV. Fourteen of the 17 facial paralysis cases improved to House-Brackmann grade II or lower at an average of 57.6 days after the initial evaluation. Thirty-one patients underwent initial and follow-up pure tone audiometry examinations. The air-bone gap closed significantly from 27.2 dB at an average of 21.8 days post-trauma to 19.6 dB at an average of 79.9 days post-trauma, without the need for surgical intervention. Initial conservative treatment for facial paralysis or conductive hearing loss is possible in otic capsule sparing fracture cases after careful evaluation of the patient.

  19. Evaluation of Advanced Bionics high resolution mode.

    PubMed

    Buechner, Andreas; Frohne-Buechner, Carolin; Gaertner, Lutz; Lesinski-Schiedat, Anke; Battmer, Rolf-Dieter; Lenarz, Thomas

    2006-07-01

    The objective of this paper is to evaluate the advantages of the Advanced Bionic high resolution mode for speech perception, through a retrospective analysis. Forty-five adult subjects were selected who had a minimum experience of three months' standard mode (mean of 10 months) before switching to high resolution mode. Speech perception was tested in standard mode immediately before fitting with high resolution mode, and again after a maximum of six months high resolution mode usage (mean of two months). A significant improvement was found, between 11 and 17%, depending on the test material. The standard mode preference does not give any indication about the improvement when switching to high resolution. Users who are converted within any study achieve a higher performance improvement than those converted in the clinical routine. This analysis proves the significant benefits of high resolution mode for users, and also indicates the need for guidelines for individual optimization of parameter settings in a high resolution mode program.

  20. Virtual temporal bone: an interactive 3-dimensional learning aid for cranial base surgery.

    PubMed

    Kockro, Ralf A; Hwang, Peter Y K

    2009-05-01

    We have developed an interactive virtual model of the temporal bone for the training and teaching of cranial base surgery. The virtual model was based on the tomographic data of the Visible Human Project. The male Visible Human's computed tomographic data were volumetrically reconstructed as virtual bone tissue, and the individual photographic slices provided the basis for segmentation of the middle and inner ear structures, cranial nerves, vessels, and brainstem. These structures were created by using outlining and tube editing tools, allowing structural modeling either directly on the basis of the photographic data or according to information from textbooks and cadaver dissections. For training and teaching, the virtual model was accessed in the previously described 3-dimensional workspaces of the Dextroscope or Dextrobeam (Volume Interactions Pte, Ltd., Singapore), whose interfaces enable volumetric exploration from any perspective and provide virtual tools for drilling and measuring. We have simulated several cranial base procedures including approaches via the floor of the middle fossa and the lateral petrous bone. The virtual model suitably illustrated the core facts of anatomic spatial relationships while simulating different stages of bone drilling along a variety of surgical corridors. The system was used for teaching during training courses to plan and discuss operative anatomy and strategies. The Virtual Temporal Bone and its surrounding 3-dimensional workspace provide an effective way to study the essential surgical anatomy of this complex region and to teach and train operative strategies, especially when used as an adjunct to cadaver dissections.

  1. High-resolution slug testing.

    PubMed

    Zemansky, G M; McElwee, C D

    2005-01-01

    The hydraulic conductivity (K) variation has important ramifications for ground water flow and the transport of contaminants in ground water. The delineation of the nature of that variation can be critical to complete characterization of a site and the planning of effective and efficient remedial measures. Site-specific features (such as high-conductivity zones) need to be quantified. Our alluvial field site in the Kansas River valley exhibits spatial variability, very high conductivities, and nonlinear behavior for slug tests in the sand and gravel aquifer. High-resolution, multilevel slug tests have been performed in a number of wells that are fully screened. A general nonlinear model based on the Navier-Stokes equation, nonlinear frictional loss, non-Darcian flow, acceleration effects, radius changes in the wellbore, and a Hvorslev model for the aquifer has been used to analyze the data, employing an automated processing system that runs within the Excel spreadsheet program. It is concluded that slug tests can provide the necessary data to identify the nature of both horizontal and vertical K variation in an aquifer and that improved delineation or higher resolution of K structure is possible with shorter test intervals. The gradation into zones of higher conductivity is sharper than seen previously, and the maximum conductivity observed is greater than previously measured. However, data from this project indicate that well development, the presence of fines, and the antecedent history of the well are important interrelated factors in regard to slug-test response and can prevent obtaining consistent results in some cases.

  2. A 3-D geometric morphometric study of intraspecific variation in the ontogeny of the temporal bone in modern Homo sapiens.

    PubMed

    Smith, Heather F; Ritzman, Terrence; Otárola-Castillo, Erik; Terhune, Claire E

    2013-11-01

    This study addresses how the human temporal bone develops the population-specific pattern of morphology observed among adults and at what point in ontogeny those patterns arise. Three-dimensional temporal bone shape was captured using 15 landmarks on ontogenetic series of specimens from seven modern human populations. Discriminant function analysis revealed that population-specific temporal bone morphology is evident early in ontogeny, with significant shape differences among many human populations apparent prior to the eruption of the first molar. As early as five years of age, temporal bone shape reflects population history and can be used to reliably sort populations, although those in closer geographic proximity and molecular affinity are more likely to be misclassified. The deviation of cold-adapted populations from this general pattern of congruence between temporal bone morphology and genetic distances, identified in previous work, was confirmed here in adult and subadult specimens, and was revealed to occur earlier in ontogeny than previously recognized. Significant differences exist between the ontogenetic trajectories of some pairs of populations, but not among others, and the angles of these trajectories do not reflect genetic relationships or final adult temporal bone size. Significant intrapopulation differences are evident early in ontogeny, with differences becoming amplified by divergent trajectories in some groups. These findings elucidate how the congruence between adult human temporal bone morphology and population history develops, and reveal that this pattern corresponds closely to that described previously for facial ontogeny.

  3. Gorham-Stout syndrome affecting the temporal bone with cerebrospinal fluid leakage.

    PubMed

    Morimoto, Noriko; Ogiwara, Hideki; Miyazaki, Osamu; Kitamuara, Masayuki; Nishina, Sachiko; Nakazawa, Atsuko; Maekawa, Takanobu; Morota, Nobuhito

    2013-09-01

    Gorham-Stout syndrome is a rare disorder characterized by progressive osteolysis that leads to the disappearance of bone. Lymphvascular proliferation causes the local destruction of bony tissue. Owing to the low incidence of this syndrome, little is known about its etiology or treatment. We present an 11-year-old girl with Gorham-Stout syndrome that involved right petrous apex in temporal bone and upper clivus, which cause intracranial pressure increase and cerebrospinal fluid (CSF) leakage. The patient required surgical repair of CSF leakage by extradural middle fossa approach with temporal fascia flap. Combined treatment with interferon and propranolol prevented the progression of osteolysis. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

  4. Epidemic typhus fever and hearing loss: a histological study (Hallpike collection of temporal bone sections).

    PubMed

    Friedmann, I; Frohlich, A; Wright, A

    1993-04-01

    Hearing loss as a frequent complication of louse-borne epidemic typhus fever has been well documented in the reports of ENT specialists serving in both the Allied and the German armies in the last war. The present paper describes the characteristic histopathological features as noted in sections of the temporal bones from five British soldiers who died in 1944 of typhus fever during the last war in Eastern Asia. The VIIIth nerve showed multiple 'typhus nodules' and there was extensive interstitial neuritis of the VIIIth nerve and demyelination of the nerve fibres. There were also widely scattered aggregations of mononuclear cells in the inner ear. This unique study was based on the Hallpike collection of temporal bone sections.

  5. Computed tomography of temporal bone pneumatization. 1. Normal pattern and morphology

    SciTech Connect

    Virapongse, C.; Sarwar, M.; Bhimani, S.; Sasaki, C.; Shapiro, R.

    1985-09-01

    The pneumatization of 141 normal temporal bones on computed tomography (CT) was evaluated in 100 patients. Because of the controversy surrounding the sclerotic squamomastoid (mastoid), temporal bones with this finding were discarded. A CT index of pneumatization was based on the pneumatized area and the number of cells seen within a representative scanning section. Results suggest that squamomastoid pneumatization follows the classic normal distribution and does not correlate with age, gender, or laterality. A high degree of symmetry was found in 41 patients who had both ears examined. Air-cell configuration was variable. Air-cell size tended to increase progressively from the mastoid antrum. The scutum pseudotumor appearance caused by incomplete pneumatization was seen frequently, and should not be mistaken for mastoiditis or an osteoma. Thick sections producing partial-volume effect may also produce this spurious finding. Therefore, when searching for mucosal thickening due to mastoiditis, large air cells should preferably be analyzed.

  6. A New Surgical Approach for Direct Acoustic Cochlear Implant: A Temporal Bone Study

    PubMed Central

    Bruschini, Luca; Forli, Francesca; Vito, Andrea De; Berrettini, Stefano

    2016-01-01

    Objectives The direct acoustic cochlear implant (DACI) is among the latest developments in the field of implantable acoustic prostheses. The surgical procedure requires a mastoidectomy and a posterior-inferior tympanotomy, with access to the facial recess at the level of the oval window, in a complex and lengthy surgical approach. Here, we report a new and considerably shorter surgical approach. Methods The new approach involves positioning of artificial incus above the oval window through the superior-anterior tympanotomy. We performed DACI placement in temporal bone specimens (n=5) to assess the feasibility of the new approach. Results The average time for the DACI implant in the temporal bones was only 112 minutes (range, 94 to 142 minutes) and there was little clinical risk associated with the procedure. Access was easy and drilling was minimal. Conclusion Our approach simplified the surgical procedure and consequently reduced the time required for DACI placement. PMID:27334513

  7. Temporal bone carcinoma: a first glance beyond the conventional clinical and pathological prognostic factors.

    PubMed

    Marioni, Gino; Martini, Alessandro; Favaretto, Niccolò; Franchella, Sebastiano; Cappellesso, Rocco; Marino, Filippo; Blandamura, Stella; Mazzoni, Antonio; Zanoletti, Elisabetta

    2016-10-01

    Temporal bone squamous cell carcinoma (TBSCC) is an uncommon, aggressive malignancy with a poor prognosis in advanced cases. The dismal outcome is partially related to: the lack of reliable clinical or pathological prognostic factors and the largely unstandardized surgical and integrated treatments adopted. There is an undeniable need for novel diagnostic/therapeutic strategies to improve the prognosis. The purpose of this critical review was to explore the level of available knowledge concerning the molecular markers involved in the biology of TBSCC that have a prognostic potential. The Pub-Med and Scopus electronic databases were searched without publication date limits for studies investigating molecular markers in cohorts of patients with primary TBSCC. The search terms used were: "temporal bone cancer", "temporal bone carcinoma", "temporal bone malignancy", "ear cancer", "ear carcinoma", and "ear malignancy". We decided preliminarily not to consider series with less than five cases. Nine retrospective case series of TBSCC were found in which different analytical techniques had been used to study the role of several biomarkers (HPV, vimentin, transforming growth factor β, CD105, RECK, matrix metalloproteinase-9, MASPIN, EBV, p16, TP53 mutation, pSTAT3, relaxin-2). CD105 expression (in tumor vessel endothelial cells) and MASPIN cytoplasmic expression (in carcinoma cells) were, respectively, found directly and inversely related with the neoplasm's recurrence rate. CD105 expression was also inversely related with disease-free survival in TBSCC. A future goal of such analyses should be to ascertain the radio- and chemo-sensitivity profiles of individual TBSCCs, enabling truly personalized therapies. A further, more ambitious goal will be to find targets for therapeutic agents that might prove crucial in improving the disease-specific survival for patients with advanced TBSCC.

  8. Variability of the temporal bone surface's topography: implications for otologic surgery

    NASA Astrophysics Data System (ADS)

    Lecoeur, Jérémy; Noble, Jack H.; Balachandran, Ramya; Labadie, Robert F.; Dawant, Benoit M.

    2012-02-01

    Otologic surgery is performed for a variety of reasons including treatment of recurrent ear infections, alleviation of dizziness, and restoration of hearing loss. A typical ear surgery consists of a tympanomastoidectomy in which both the middle ear is explored via a tympanic membrane flap and the bone behind the ear is removed via mastoidectomy to treat disease and/or provide additional access. The mastoid dissection is performed using a high-speed drill to excavate bone based on a pre-operative CT scan. Intraoperatively, the surface of the mastoid component of the temporal bone provides visual feedback allowing the surgeon to guide their dissection. Dissection begins in "safe areas" which, based on surface topography, are believed to be correlated with greatest distance from surface to vital anatomy thus decreasing the chance of injury to the brain, large blood vessels (e.g. the internal jugular vein and internal carotid artery), the inner ear, and the facial nerve. "Safe areas" have been identified based on surgical experience with no identifiable studies showing correlation of the surface with subsurface anatomy. The purpose of our study was to investigate whether such a correlation exists. Through a three-step registration process, we defined a correspondence between each of twenty five clinically-applicable temporal bone CT scans of patients and an atlas and explored displacement and angular differences of surface topography and depth of critical structures from the surface of the skull. The results of this study reflect current knowledge of osteogenesis and anatomy. Based on two features (distance and angular difference), two regions (suprahelical and posterior) of the temporal bone show the least variability between surface and subsurface anatomy.

  9. A Method of Treatment for Persisting Cerebellar Encephalocele of the Temporal Bone

    PubMed Central

    Goravalingappa, Ravi; Mahadeviah, A.

    1996-01-01

    Temporal lobe herniation or meningoencephaloceles through the tegmen bone are rare entities but are well-described lesions in the literature. They can be successfully approached through the middle fossa alone or combined with a transmastoid approach, and are repaired with fascia, bone, or cartilage. However, cerebellar encephaloceles penetrating the posterior fossa dural plate and presenting as pulsatile postauricular mass are rare. In this paper, we report successful treatment of a cerebellar encephalocele by cranialization of the mastoid cavity using a calvarial bone graft and closure of the external auditory canal. A prior suboccipital approach, as recommended by others, had failed. The patient has remained well for 1 year with no recurrence. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:17170979

  10. Advanced bionics thin lateral and Helix II electrodes: a temporal bone study.

    PubMed

    Wright, Charles G; Roland, Peter S; Kuzma, Janusz

    2005-11-01

    This study was performed to evaluate the insertional properties of two cochlear implant electrodes recently developed by Advanced Bionics Corporation. Anatomic study using human cadaveric temporal bones. The electrode prototypes we tested are the Thin Lateral and Helix II arrays, which incorporate features designed to minimize insertional trauma. A total of eight electrodes (4 of each prototype) were evaluated after insertion into freshly fixed temporal bones. The electrodes were inserted by way of standard cochleostomies, and the specimens were subsequently dissected to assess electrode position, insertion depth, and intracochlear trauma. Quantitative data regarding insertion depths and contact distances from the modiolus are presented for all electrodes tested. The mean insertion depths were 368 degrees for the Thin Lateral electrodes, which are designed to approximate the lateral cochlear wall, and 436 degrees for the Helix II electrodes, which occupy a more medial position in the scala tympani. No evidence of insertional trauma was observed with either electrode. The ease of insertion and absence of trauma were confirmed during additional trials in which electrode behavior was directly observed during insertion into previously opened cochleas. Both electrodes performed favorably in our human temporal bone trials, and both arrays appear promising for clinical use, especially in patients with residual hearing in whom atraumatic insertion is an important objective.

  11. Multicenter experiences in temporal bone cancer surgery based on 89 cases

    PubMed Central

    Wierzbicka, Małgorzata; Niemczyk, Kazimierz; Bruzgielewicz, Antoni; Durko, Marcin; Klatka, Janusz; Kopeć, Tomasz; Osuch-Wójcikiewicz, Ewa; Pietruszewska, Wioletta; Szymański, Marcin; Szyfter, Witold

    2017-01-01

    Objective To present outcomes of extensive surgery: lateral, subtotal, total petrosectomies in patients with temporal bone invasion resulting from specific primary cancers. Study design Retrospective case review. Setting Four tertiary referral centers. Material 89 patients with cancer of the temporal bone treated between January 2006 and December 2010. Intervention Multidisciplinary team approach including surgical resection, reconstruction, and postoperative radiotherapy. Main outcome measure Disease-specific survival, overall survival. Results In 27.0% of the patients, relapse was reported, with an average of 6.3 months after surgery; 31 patients (34.8%) died during the follow-up. The average mortality was 22.1 months. Fifty-four patients (58.7%) stayed alive during the time of observation. The average survival time was 42.0 months. The median time of survival with relapse was 12 months (range: 1–51 months). The three-year disease-free rate was 38.0% and the overall survival rate was 58.7%. Conclusions Petrosectomy is an effective treatment for malignant temporal bone invasion. The probability of a good outcome was statistically decreased with a high T grade, positive margins, and salvage surgery. Younger age is connected with better prognosis. One of the major tasks remains to improve detection and to shorten the time to diagnosis, keeping in mind that symptoms are insidious and in younger people, the time before diagnosis was longer. PMID:28225795

  12. Temporal bone MRI with 3D-FIESTA in the evaluation of facial and audiovestibular dysfunction.

    PubMed

    Cavusoglu, M; Cılız, D S; Duran, S; Ozsoy, A; Elverici, E; Karaoglanoglu, R; Sakman, B

    2016-09-01

    To evaluate the clinical usefulness of magnetic resonance imaging (MRI) of the temporal bone using three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA) sequences in patients with facial and audiovestibular dysfunction. We retrospectively reviewed the MR images of 1263 patients who presented with hearing loss (n=429), peripheral facial palsy (n=96), tinnitus (n=341) or vertigo (n=397). There were 605 men and 658 women, with a mean age of 46.97±16.95 (SD) years (range: 2-83 years). Positive MRI findings that were responsible for clinical manifestations in individual patients were categorized according to the anatomic sites and etiologies of the lesions. Positive MRI findings possibly responsible for clinical manifestations were found in 232/1263 (18.37%) patients, including 86/429 (20.05%) patients with hearing loss, 21/96 (21.88%) patients with facial palsy, 62/341 (18.18%) patients with tinnitus, and 63/397 (15.87%) patients with vertigo. Although the use of MRI of the temporal bone using 3D-FIESTA shows positive findings in only 18.37% of patients, it provides important information in those with facial and audiovestibular dysfunction. However, for patients with normal MRI of the temporal bone, other etiological factors should be investigated in order to clarify or elucidate the cause of clinical manifestations. Copyright © 2015 Éditions françaises de radiologie. Published by Elsevier Masson SAS. All rights reserved.

  13. Quantifying temporal bone morphology of great apes and humans: an approach using geometric morphometrics

    PubMed Central

    Lockwood, Charles A; Lynch, John M; Kimbel, William H

    2002-01-01

    The hominid temporal bone offers a complex array of morphology that is linked to several different functional systems. Its frequent preservation in the fossil record gives the temporal bone added significance in the study of human evolution, but its morphology has proven difficult to quantify. In this study we use techniques of 3D geometric morphometrics to quantify differences among humans and great apes and discuss the results in a phylogenetic context. Twenty-three landmarks on the ectocranial surface of the temporal bone provide a high level of anatomical detail. Generalized Procrustes analysis (GPA) is used to register (adjust for position, orientation and scale) landmark data from 405 adults representing Homo, Pan, Gorilla and Pongo. Principal components analysis of residuals from the GPA shows that the major source of variation is between humans and apes. Human characteristics such as a coronally orientated petrous axis, a deep mandibular fossa, a projecting mastoid process, and reduced lateral extension of the tympanic element strongly impact the analysis. In phenetic cluster analyses, gorillas and orangutans group together with respect to chimpanzees, and all apes group together with respect to humans. Thus, the analysis contradicts depictions of African apes as a single morphotype. Gorillas and orangutans lack the extensive preglenoid surface of chimpanzees, and their mastoid processes are less medially inflected. These and other characters shared by gorillas and orangutans are probably primitive for the African hominid clade. PMID:12489757

  14. [High-resolution computed tomography in stapes surgery].

    PubMed

    Oberascher, G; Grobovschek, M

    1987-06-01

    Early and delayed complications in the inner or middle ear may follow stapedectomy or stapedotomy and may require revision surgery. Nowadays high resolution middle ear computed tomography (HR-MCT) using a special interpolation technique can demonstrate the smallest structures of the middle ear space, such as the long process of the incus and stapes. Stapes prostheses can also be seen in this way, but to identify the prothesis exactly it is necessary to determine the position of the piston hook in relation to the incus and of the piston shaft to the foot plate and scala vestibuli. Two points were of particular interest to us: HR-MCT identification of various metal and plastic pistons. Clinical significance of HR-MCT in complications following surgery. As the result of our experimental research on cadaver temporal bones, pistons must still be divided into four groups based on their demonstration by HR-MCT: Group I (e.g. Stainless Steel Cup Piston): whole piston visible. Group II (e.g. McGee Stainless Steel Piston): only piston shaft. Group III (Fisch Teflon-Platinum Piston): only hook visible. Group IV (e.g. Fisch Teflon-Wire Piston): piston hardly visible or not at all. In groups I-III it is possible to discover whether the piston is too long or too short, whether it is dislocated or has slipped. Group IV pistons, hooks from group II and the shaft from group III must be changed to allow detection by x-rays. With plastic pistons it might be possible to add an x-ray agent.2+ improvements in manufacture appear to be necessary, dislocation of various prostheses can now be shown.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. High Resolution TPM Cosmological Simulations

    NASA Astrophysics Data System (ADS)

    Xu, Guohong

    1995-01-01

    studied several variations of Cold Dark Matter (CDM) type. The standard CDM model, although with many known problems, is treated to compare with the previous simulations. The low density models with and without a cosmological constant are of special interest because they give better fit to the large scale structure and much observational evidence implies that Omega_0 < 1.. With our high resolution simulations, we are specially interested to study the structure of the objects from different cosmological models. The slopes of the dark halo density profiles from different models are only slightly different from each other, with a broad distribution within each model. All the models can successfully produce flat rotation curves for dark halos. We find the biggest difference in the cluster structure among various models is the predicted X-ray core radius. The standard CDM model predicts bigger X-ray core radius than the low density models, but all the models predicts smaller core radius than that from X-ray observations. We find the low density models can produce significant substructures in X-ray clusters to be in agreement with observations, while the X-ray clusters in the standard CDM model are known to have abundant substructures.

  16. Characterization of Ultrasound Propagation Through Ex-vivo Human Temporal Bone

    PubMed Central

    Ammi, Azzdine Y.; Mast, T. Douglas; Huang, I-Hua; Abruzzo, Todd A.; Coussios, Constantin-C.; Shaw, George J.; Holland, Christy K.

    2016-01-01

    Adjuvant therapies that lower the thrombolytic dose or increase its efficacy would represent a significant breakthrough in the treatment of patients with ischemic stroke (Eggers 2006; Tsivgoulis and Alexandrov 2007). The objective of this study was to perform intracranial measurements of the acoustic pressure field generated by 0.12, 1.03 and 2.00 MHz ultrasound transducers to identify optimal ultrasound parameters that would maximize penetration and minimize aberration of the beam. To achieve this goal, in vitro experiments were conducted on five human skull specimens. In a water-filled tank, two unfocused transducers (0.12 and 1.03 MHz) and one focused transducer (2.00 MHz) were consecutively placed near the right temporal bone of each skull. A hydrophone, mounted on a micropositioning system, was moved to an estimated location of the middle cerebral artery (MCA) origin and measurements of the surrounding acoustic pressure field were performed. For each measurement, the distance from the position of maximum acoustic pressure to the estimated origin of the MCA inside the skulls was quantified. The –3 dB depth of field and beam width in the skull were also investigated as a function of the three frequencies. Results show that the transducer alignment relative to the skull is a significant determinant of the detailed behavior of the acoustic field inside the skull. For optimal penetration, insonation normal to the temporal bone was needed. The shape of the 0.12-MHz intracranial beam was more distorted than those at 1.03 and 2.00 MHz due to the large aperture and beam width. However, lower ultrasound pressure reduction was observed at 0.12 MHz (22.5%). At 1.03 and 2.00 MHz two skulls had an insufficient temporal bone window and attenuated the beam severely (up to 96.6% pressure reduction). For all frequencies, constructive and destructive interference patterns were seen near the contralateral skull wall at various elevations. The 0.12-MHz ultrasound beam depth of

  17. Prevalence of Cochlear-Facial Dehiscence in a Study of 1,020 Temporal Bone Specimens.

    PubMed

    Fang, Christina H; Chung, Sei Yeon; Blake, Danielle M; Vazquez, Alejandro; Li, Chengrui; Carey, John P; Francis, Howard W; Jyung, Robert W

    2016-08-01

    To determine the prevalence of cochlear-facial dehiscence (CFD) and to examine the influence of otic capsule area, age, sex, and race on CFD. Descriptive study of archived temporal bone specimens. Targeted sections from 1,020 temporal bone specimens were scanned and examined for CFD. Cochlear-facial partition width (CFPW) and otic capsule area (OCA), a marker of bone thickness, were measured using image analysis software. Demographic data were analyzed using multiple linear regression analysis. The mean CFPW was 0.23 mm (range, 0-0.92 mm; SD, 0.15 mm). Six patients were completely dehiscent (0.59%). Fallopian canal width, age, sex, race, and OCA were found to be significant predictors of CFPW. Age was found to be negatively correlated with CFPW (β = -0.001) (p < 0.005). Thicker CFPW was associated with males (β = 0.024) and non-Caucasian individuals (β = 0.031). The mean OCA for dehiscent specimens (mean, 9.48 mm; range, 6.65-11.58 mm; SD 3.21 mm) was significantly smaller than the mean OCA for nondehiscent specimens, (mean, 12.88 mm; range, 6.63-21.92 mm; SD, 2.47 mm) (p < 0.01). CFD occurred in nearly 0.6% of specimens in this temporal bone collection. Close to 35% of patients were sufficiently thin (<0.1 mm) to appear dehiscent on computed tomography scanning. Smaller OCA correlated with thinner CFPW, suggesting a developmental factor. Older, female, and Caucasian patients may have a greater risk for CFD and its associated symptoms.

  18. High resolution scintillation detector with semiconductor readout

    DOEpatents

    Levin, Craig S.; Hoffman, Edward J.

    2000-01-01

    A novel high resolution scintillation detector array for use in radiation imaging such as high resolution Positron Emission Tomography (PET) which comprises one or more parallelepiped crystals with at least one long surface of each crystal being in intimate contact with a semiconductor photodetector such that photons generated within each crystal by gamma radiation passing therethrough is detected by the photodetector paired therewith.

  19. High Resolution PDF Measurements on Ag Nanoparticles

    SciTech Connect

    Rocha, Tulio C. R.; Martin, Chris; Kycia, Stefan; Zanchet, Daniela

    2009-01-29

    The quantitative analysis of structural defects in Ag nanoparticles was addressed in this work. We performed atomic scale structural characterization by a combination of x-ray diffraction (XRD) using the Pair Distribution Function analysis (PDF) and High Resolution Transmission Electron Microscopy (HRTEM). The XRD measurements were performed using an innovative instrumentation setup to provide high resolution PDF patterns.

  20. Polyester wax: a new embedding medium for the histopathologic study of human temporal bones.

    PubMed

    Merchant, Saumil N; Burgess, Barbara; O'Malley, Jennifer; Jones, Diane; Adams, Joe C

    2006-02-01

    Celloidin and paraffin are the two common embedding mediums used for histopathologic study of the human temporal bone by light microscopy. Although celloidin embedding permits excellent morphologic assessment, celloidin is difficult to remove, and there are significant restrictions on success with immunostaining. Embedding in paraffin allows immunostaining to be performed, but preservation of cellular detail within the membranous labyrinth is relatively poor. Polyester wax is an embedding medium that has a low melting point (37 degrees C), is soluble in most organic solvents, is water tolerant, and sections easily. We hypothesized that embedding in polyester wax would permit good preservation of the morphology of the membranous labyrinth and, at the same time, allow the study of proteins by immunostaining. Nine temporal bones from individuals aged 1 to 94 years removed 2 to 31 hours postmortem, from subjects who had no history of otologic disease, were used. The bones were fixed using 10% formalin, decalcified using EDTA, embedded in polyester wax, and serially sectioned at a thickness of 8 to 12 mum on a rotary microtome. The block and knife were cooled with frozen CO2 (dry ice) held in a funnel above the block. Sections were placed on glass slides coated with a solution of 1% fish gelatin and 1% bovine albumin, followed by staining of selected sections with hematoxylin and eosin (H&E). Immunostaining was also performed on selected sections using antibodies to 200 kD neurofilament and Na-K-ATPase. Polyester wax-embedded sections demonstrated good preservation of cellular detail of the organ of Corti and other structures of the membranous labyrinth, as well as the surrounding otic capsule. The protocol described in this paper was reliable and consistently yielded sections of good quality. Immunostaining was successful with both antibodies. The use of polyester wax as an embedding medium for human temporal bones offers the advantage of good preservation of

  1. Polyester Wax: A New Embedding Medium for the Histopathologic Study of Human Temporal Bones

    PubMed Central

    Merchant, Saumil N.; Burgess, Barbara; O'Malley, Jennifer; Jones, Diane; Adams, Joe C.

    2007-01-01

    Background Celloidin and paraffin are the two common embedding mediums used for histopathologic study of the human temporal bone by light microscopy. Although celloidin embedding permits excellent morphologic assessment, celloidin is difficult to remove, and there are significant restrictions on success with immunostaining. Embedding in paraffin allows immunostaining to be performed, but preservation of cellular detail within the membranous labyrinth is relatively poor. Objectives/Hypothesis Polyester wax is an embedding medium that has a low melting point (37°C), is soluble in most organic solvents, is water tolerant, and sections easily. We hypothesized that embedding in polyester wax would permit good preservation of the morphology of the membranous labyrinth and, at the same time, allow the study of proteins by immunostaining. Methods Nine temporal bones from individuals aged 1 to 94 years removed 2 to 31 hours postmortem, from subjects who had no history of otologic disease, were used. The bones were fixed using 10% formalin, decal-cified using EDTA, embedded in polyester wax, and serially sectioned at a thickness of 8 to 12 μm on a rotary microtome. The block and knife were cooled with frozen CO2 (dry ice) held in a funnel above the block. Sections were placed on glass slides coated with a solution of 1% fish gelatin and 1% bovine albumin, followed by staining of selected sections with hematoxylin and eosin (H&E). Immunostaining was also performed on selected sections using antibodies to 200 kD neurofilament and Na-K-ATPase. Results Polyester wax–embedded sections demonstrated good preservation of cellular detail of the organ of Corti and other structures of the membranous labyrinth, as well as the surrounding otic capsule. The protocol described in this paper was reliable and consistently yielded sections of good quality. Immuno-staining was successful with both antibodies. Conclusion The use of polyester wax as an embedding medium for human temporal

  2. Transtemporal management of temporal bone encephaloceles and CSF leaks: review of 56 consecutive patients.

    PubMed

    Kari, Elina; Mattox, Douglas E

    2011-04-01

    This report details our experience in the management of 56 consecutive patients with mastoid encephaloceles and cerebrospinal fluid (CSF) leaks. The majority were managed through the transmastoid route with temporalis fascia and calvarial bone graft. Among the patients operated on at least 18 months before analysis, there was a median follow-up of 54 months with no intracranial complications. The average body mass index (BMI) of patients with spontaneous CSF leaks was found to be statistically significantly greater than that of patients with CSF leaks with traumatic, infectious or iatrogenic etiologies. To investigate the long-term follow-up of patients with spontaneous, iatrogenic, and traumatic temporal bone encephaloceles and CSF leaks to determine the effectiveness of the repair, late intracranial complications, and recurrent lesions. This is a retrospective review from a tertiary care center of 56 consecutive patients managed with CSF otorrhea, encephaloceles, and spontaneous pneumocephalus. All patients were repaired through transtemporal, middle cranial fossa or combined approaches for extradural repair and bone grafting. Of the 56 consecutive cases, 12 had CSF otorrhea alone, 19 had encephaloceles, and 23 had both. Two patients presented with spontaneous pneumocephalus without CSF leak. Thirty-three patients had spontaneous onset of their lesion without any history of temporal bone surgery or trauma. The average BMI of patients with spontaneous CSF leaks was found to be greater than the average BMI of patients with CSF leaks due to traumatic, infectious or iatrogenic causes. This difference was found to be statistically significant. Six of these had either preceding or subsequent contralateral mastoid or anterior fossa (sphenoid, ethmoid) CSF leak. Intracranial pressure was evaluated in these cases and most underwent VP shunting to reduce their intracranial pressure. Sixteen cases followed previous mastoid surgery or chronic ear disease and seven were

  3. Topographical anatomy and morphometry of the temporal bone of the macaque.

    PubMed

    Wysocki, J

    2009-02-01

    Based on the dissections of 24 bones of 12 macaques (Macaca mulatta), a systematic anatomical description was made and measurements of the chosen size parameters of the temporal bone as well as the skull were taken. Although there is a small mastoid process, the general arrangement of the macaque's temporal bone structures is very close to that which is observed in humans. The main differences are a different model of pneumatisation and the presence of subarcuate fossa, which possesses considerable dimensions. The main air space in the middle ear is the mesotympanum, but there are also additional air cells: the epitympanic recess containing the head of malleus and body of incus, the mastoid cavity, and several air spaces on the floor of the tympanic cavity. The vicinity of the carotid canal is also very well pneumatised and the walls of the canal are very thin. The semicircular canals are relatively small, very regular in shape, and characterized by almost the same dimensions. The bony walls of the labyrinth are relatively thin.

  4. Mastoidectomy dimensions for direct acoustic cochlear implantation: a human cadaveric temporal bone study.

    PubMed

    Fiorino, Francesco; Amadori, Maurizio

    2017-02-28

    The objective of the present paper was to acquire information about the mastoidectomy size necessary to obtain an optimal placement of the direct acoustic cochlear implant actuator and fixation system. Ten human cadaveric temporal bones were dissected and implanted with direct acoustic cochlear implant. Mastoidectomy size was determined after implantation in each temporal bone. A bone bed for the receiver/stimulator, mastoidectomy and a large posterior tympanotomy were drilled out. The mastoidectomy was progressively enlarged posteriorly in small steps until the actuator template was judged adequately oriented to enable passage of the rod through the posterior tympanotomy without any contact with the bony walls. The distance between different landmarks in the mastoidectomy was measured. All measured values showed a high degree of consistency, with limited median absolute deviation values. One of the most critical measure, i.e. the distance between the posterior margin of the mastoidectomy to the superior rim of the bony external ear canal wall, ranged from 13 to 16 mm with a median value of 15 mm. Prior knowledge of the ideal size of the mastoidectomy for direct acoustic cochlear implant facilitates the positioning of the fixation system and may save time during implant surgery.

  5. Texture analysis of high-resolution FLAIR images for TLE

    NASA Astrophysics Data System (ADS)

    Jafari-Khouzani, Kourosh; Soltanian-Zadeh, Hamid; Elisevich, Kost

    2005-04-01

    This paper presents a study of the texture information of high-resolution FLAIR images of the brain with the aim of determining the abnormality and consequently the candidacy of the hippocampus for temporal lobe epilepsy (TLE) surgery. Intensity and volume features of the hippocampus from FLAIR images of the brain have been previously shown to be useful in detecting the abnormal hippocampus in TLE. However, the small size of the hippocampus may limit the texture information. High-resolution FLAIR images show more details of the abnormal intensity variations of the hippocampi and therefore are more suitable for texture analysis. We study and compare the low and high-resolution FLAIR images of six epileptic patients. The hippocampi are segmented manually by an expert from T1-weighted MR images. Then the segmented regions are mapped on the corresponding FLAIR images for texture analysis. The 2-D wavelet transforms of the hippocampi are employed for feature extraction. We compare the ability of the texture features from regular and high-resolution FLAIR images to distinguish normal and abnormal hippocampi. Intracranial EEG results as well as surgery outcome are used as gold standard. The results show that the intensity variations of the hippocampus are related to the abnormalities in the TLE.

  6. Direct radiocarbon dating and DNA analysis of the Darra-i-Kur (Afghanistan) human temporal bone.

    PubMed

    Douka, Katerina; Slon, Viviane; Stringer, Chris; Potts, Richard; Hübner, Alexander; Meyer, Matthias; Spoor, Fred; Pääbo, Svante; Higham, Tom

    2017-06-01

    The temporal bone discovered in the 1960s from the Darra-i-Kur cave in Afghanistan is often cited as one of the very few Pleistocene human fossils from Central Asia. Here we report the first direct radiocarbon date for the specimen and the genetic analyses of DNA extracted and sequenced from two areas of the bone. The new radiocarbon determination places the find to ∼4500 cal BP (∼2500 BCE) contradicting an assumed Palaeolithic age of ∼30,000 years, as originally suggested. The DNA retrieved from the specimen originates from a male individual who carried mitochondrial DNA of the modern human type. The petrous part yielded more endogenous ancient DNA molecules than the squamous part of the same bone. Molecular dating of the Darra-i-Kur mitochondrial DNA sequence corroborates the radiocarbon date and suggests that the specimen is younger than previously thought. Taken together, the results consolidate the fact that the human bone is not associated with the Pleistocene-age deposits of Darra-i-Kur; instead it is intrusive, possibly re-deposited from upper levels dating to much later periods (Neolithic). Despite its Holocene age, the Darra-i-Kur specimen is, so far, the first and only ancient human from Afghanistan whose DNA has been sequenced. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. The temporal bones from Sima de los Huesos Middle Pleistocene site (Sierra de Atapuerca, Spain). A phylogenetic approach.

    PubMed

    Martínez, I; Arsuaga, J L

    1997-01-01

    Three well-preserved crania and 22 temporal bones were recovered from the Sima de los Huesos Middle Pleistocene site up to and including the 1994 field season. This is the largest sample of hominid temporal bones known from a single Middle Pleistocene site and it offers the chance to characterize the temporal bone morphology of an European Middle Pleistocene population and to study the phylogenetic relationships of the SH sample with other Upper and Middle Pleistocene hominids. We have carried out a cladistic analysis based on nine traits commonly used in phylogenetic analysis of Middle and Late Pleistocene hominids: shape of the temporal squama superior border, articular eminence morphology, contribution of the sphenoid bone to the median glenoid wall, postglenoid process projection, tympanic plate orientation, presence of the styloid process, mastoid process projection, digastric groove morphology and anterior mastoid tubercle. We have found two autapomorphies on the Home erectus temporal bone: strong reduction of the postglenoid process and absence of the styloid process. Modern humans, Neandertals and the Middle Pleistocene fossils from Europe and Africa constitute a clade characterized by a convex superior border of the temporal squama. The European Middle Pleistocene fossils from Sima de los Huesos, Petralona, Steinheim, Bilzingsleben and Castel di Guido share a Neandertal apomorphy: a relatively flat articular eminence. The fossils from Ehringsdorf, La Chaise Suardi and Biache-Saint-Vaast also display another Neandertal derived trait: an anteriorly obliterated digastric groove. Modern humans and the African Middle Pleistocene fossils share a synapomorphy: a sagittally orientated tympanic plate.

  8. Evaluation of haptic interfaces for simulation of drill vibration in virtual temporal bone surgery.

    PubMed

    Ghasemloonia, Ahmad; Baxandall, Shalese; Zareinia, Kourosh; Lui, Justin T; Dort, Joseph C; Sutherland, Garnette R; Chan, Sonny

    2016-11-01

    Surgical training is evolving from an observership model towards a new paradigm that includes virtual-reality (VR) simulation. In otolaryngology, temporal bone dissection has become intimately linked with VR simulation as the complexity of anatomy demands a high level of surgeon aptitude and confidence. While an adequate 3D visualization of the surgical site is available in current simulators, the force feedback rendered during haptic interaction does not convey vibrations. This lack of vibration rendering limits the simulation fidelity of a surgical drill such as that used in temporal bone dissection. In order to develop an immersive simulation platform capable of haptic force and vibration feedback, the efficacy of hand controllers for rendering vibration in different drilling circumstances needs to be investigated. In this study, the vibration rendering ability of four different haptic hand controllers were analyzed and compared to find the best commercial haptic hand controller. A test-rig was developed to record vibrations encountered during temporal bone dissection and a software was written to render the recorded signals without adding hardware to the system. An accelerometer mounted on the end-effector of each device recorded the rendered vibration signals. The newly recorded vibration signal was compared with the input signal in both time and frequency domains by coherence and cross correlation analyses to quantitatively measure the fidelity of these devices in terms of rendering vibrotactile drilling feedback in different drilling conditions. This method can be used to assess the vibration rendering ability in VR simulation systems and selection of ideal haptic devices.

  9. Vestibular system changes in sudden deafness with and without vertigo: a human temporal bone study.

    PubMed

    Inagaki, Taro; Cureoglu, Sebahattin; Morita, Norimasa; Terao, Kyoichi; Sato, Teruyuki; Suzuki, Mamoru; Paparella, Michael M

    2012-09-01

    To investigate the vestibular system changes in sudden deafness with vertigo (SDwV) and sudden deafness without vertigo (SDwoV) and the cause of persistent canal paresis (CP) in SDwV patients. Retrospective study. Four temporal bones from the affected ear in 4 patients with unilateral sudden deafness (SD), 2 SDwV and 2 SDwoV, were selected. Four contralateral temporal bones with normal-hearing ears were defined as the control. Morphologic findings of the labyrinth, the number of Scarpa's ganglion cells, and the density of vestibular hair cells were investigated in all temporal bones. Clinical data and the results of vestibular tests of 11 patients with unilateral SD, as a separate group, also were investigated. Atrophic change of the organ of Corti, tectorial membrane, and stria vascularis in cochlea, and deposits and atrophic otoconial membrane in vestibular sense organs were seen on affected ears more than control ears. The density of Type I hair cells seemed to decrease on the saccular macula and the posterior semicircular canal crista on affected ears, and there was no remarkable difference between SDwV and SDwoV. In 1 patient with SDwoV who died 10 months after the onset of SD, there were large amount of deposits on the cupula, the atrophied otoconial membrane was peeling off from the saccular macula, and the saccular membrane collapsed to the saccular macula in the affected ear. In the clinical data, all SDwV who were examined within 2 years from the onset had CP, and all SDwV had profound hearing loss. There is no remarkable difference between SDwV and SDwoV in the number of Scarpa's ganglion cells and the density of vestibular hair cells. The damage of the extracellular superstructure is seen in SD with or without vertigo. The damage of extracellular superstructure is potentially one of the causes of persistent CP in patients with SD.

  10. Thermal effects of endoscopy in a human temporal bone model: Implications for endoscopic ear surgery

    PubMed Central

    Kozin, Elliott D.; Lehmann, Ashton; Carter, Margaret; Hight, Ed; Cohen, Michael; Nakajima, Hideko Heidi; Lee, Daniel J.

    2015-01-01

    Objective Although the theoretical risk of elevated temperatures during endoscopic ear surgery has been reported previously, neither temperature change nor heat distribution associated with the endoscope has been quantified. In this study, we measure temperature changes during rigid middle ear endoscopy in a human temporal bone model and investigate whether suction can act as a significant cooling mechanism. Study Design Human temporal bone model of endoscopic middle ear surgery. Methods Fresh human temporal bones were maintained at body temperature (~36°C). Temperature fluctuations were measured as a function of 1) distance between the tip of a 3mm 0° Hopkins rod and round window membrane, and 2) intensity of the light source. Infrared imaging determined the thermal gradient. For suction, a #20 French was utilized. Results We found: 1) an endoscope maximally powered by a xenon or LED light source resulted in a rapid temperature elevation up to 46°C within 0.5–1mm from the tip of the endoscope within 30–124 seconds; 2) elevated temperatures occurred up to 8mm from the endoscope tip; and 3) temperature decreased rapidly within 20–88 seconds of turning off the light source or applying suction. Conclusion Our findings have direct implications for avoiding excessive temperature elevation in endoscopic ear surgery. We recommend: 1) using submaximal light intensity, 2) frequent repositioning of the endoscope, and 3) removing the endoscope to allow tissue cooling. Use of suction provides rapid cooling of the middle ear space and may be incorporated in the design of new instrumentation for prolonged dissection. PMID:24604692

  11. Accuracy of linear drilling in temporal bone using drill press system for minimally invasive cochlear implantation

    PubMed Central

    Balachandran, Ramya; Labadie, Robert F.

    2015-01-01

    Purpose A minimally invasive approach for cochlear implantation involves drilling a narrow linear path through the temporal bone from the skull surface directly to the cochlea for insertion of the electrode array without the need for an invasive mastoidectomy. Potential drill positioning errors must be accounted for to predict the effectiveness and safety of the procedure. The drilling accuracy of a system used for this procedure was evaluated in bone surrogate material under a range of clinically relevant parameters. Additional experiments were performed to isolate the error at various points along the path to better understand why deflections occur. Methods An experimental setup to precisely position the drill press over a target was used. Custom bone surrogate test blocks were manufactured to resemble the mastoid region of the temporal bone. The drilling error was measured by creating divots in plastic sheets before and after drilling and using a microscope to localize the divots. Results The drilling error was within the tolerance needed to avoid vital structures and ensure accurate placement of the electrode; however, some parameter sets yielded errors that may impact the effectiveness of the procedure when combined with other error sources. The error increases when the lateral stage of the path terminates in an air cell and when the guide bushings are positioned further from the skull surface. At contact points due to air cells along the trajectory, higher errors were found for impact angles of 45° and higher as well as longer cantilevered drill lengths. Conclusion The results of these experiments can be used to define more accurate and safe drill trajectories for this minimally invasive surgical procedure. PMID:26183149

  12. Accuracy of linear drilling in temporal bone using drill press system for minimally invasive cochlear implantation.

    PubMed

    Dillon, Neal P; Balachandran, Ramya; Labadie, Robert F

    2016-03-01

    A minimally invasive approach for cochlear implantation involves drilling a narrow linear path through the temporal bone from the skull surface directly to the cochlea for insertion of the electrode array without the need for an invasive mastoidectomy. Potential drill positioning errors must be accounted for to predict the effectiveness and safety of the procedure. The drilling accuracy of a system used for this procedure was evaluated in bone surrogate material under a range of clinically relevant parameters. Additional experiments were performed to isolate the error at various points along the path to better understand why deflections occur. An experimental setup to precisely position the drill press over a target was used. Custom bone surrogate test blocks were manufactured to resemble the mastoid region of the temporal bone. The drilling error was measured by creating divots in plastic sheets before and after drilling and using a microscope to localize the divots. The drilling error was within the tolerance needed to avoid vital structures and ensure accurate placement of the electrode; however, some parameter sets yielded errors that may impact the effectiveness of the procedure when combined with other error sources. The error increases when the lateral stage of the path terminates in an air cell and when the guide bushings are positioned further from the skull surface. At contact points due to air cells along the trajectory, higher errors were found for impact angles of [Formula: see text] and higher as well as longer cantilevered drill lengths. The results of these experiments can be used to define more accurate and safe drill trajectories for this minimally invasive surgical procedure.

  13. Plasmacytoma of the Temporal Bone, a Great Imitator: Report of Seven Cases and Comprehensive Review of the Literature.

    PubMed

    Sweeney, Alex D; Hunter, Jacob B; Rajkumar, S Vincent; Lane, John I; Jevremovic, Dragan; Carlson, Matthew L

    2017-03-01

    To describe the clinical presentation, radiological features, and outcome of patients with plasmacytoma of the temporal bone. Multicenter retrospective case series of all patients diagnosed with plasmacytoma of the temporal bone between 1990 and 2015. Comprehensive literature review of all previously published cases. A total of seven patients (average age, 57.3 yr; 57% women) met inclusion criteria. Three (43%) had a known history of multiple myeloma (MM). The most common symptoms at presentation included otalgia, headache, and dizziness (43%, each). Five (71%) presented with a vascular appearing middle ear mass visible on otoscopy. Four of these patients did not have an established history of MM and were referred with presumptive diagnoses of paraganglioma or endolymphatic sac tumor (ELST). The average maximum tumor diameter was 3.7 cm (median, 3.5 cm; range, 0.9-6.6 cm) and the most commonly involved temporal bone subsites were the middle ear and mastoid (71% each). MM was ultimately diagnosed in six cases (86%). In addition to the new cases presented herein, 18 previously published reports were analyzed. In the 25 aggregate cases, 44% of cases were associated with MM, and the mastoid (72%) and middle ear (53%) were the most commonly involved temporal bone subsites. Plasmacytoma of the temporal bone is rare, and the clinical presentation can closely mimic that of other primary temporal bone tumors. In patients with an established history of MM, it is imperative to have a high index of suspicion for temporal bone plasmacytoma, even when radiological features suggest an alternate diagnosis.

  14. NOAA's Use of High-Resolution Imagery

    NASA Technical Reports Server (NTRS)

    Hund, Erik

    2007-01-01

    NOAA's use of high-resolution imagery consists of: a) Shoreline mapping and nautical chart revision; b) Coastal land cover mapping; c) Benthic habitat mapping; d) Disaster response; and e) Imagery collection and support for coastal programs.

  15. High Resolution Aerosol Modeling: Decadal Changes in Radiative Forcing

    SciTech Connect

    Bergmann, D J; Chuang, C C; Govindasamy, B; Cameron-Smith, P J; Rotman, D A

    2005-02-01

    The Atmospheric Science Division of LLNL has performed high-resolution calculations of direct sulfate forcing using a DOE-provided computer resource at NERSC. We integrated our global chemistry-aerosol model (IMPACT) with the LLNL high-resolution global climate model (horizontal resolution as high as 100 km) to examine the temporal evolution of sulfate forcing since 1950. We note that all previous assessments of sulfate forcing reported in IPCC (2001) were based on global models with coarse spatial resolutions ({approx} 300 km or even coarser). However, the short lifetime of aerosols ({approx} days) results in large spatial and temporal variations of radiative forcing by sulfate. As a result, global climate models with coarse resolutions do not accurately simulate sulfate forcing on regional scales. It requires much finer spatial resolutions in order to address the effects of regional anthropogenic SO{sub 2} emissions on the global atmosphere as well as the effects of long-range transport of sulfate aerosols on the regional climate forcing. By taking advantage of the tera-scale computer resources at NERSC, we simulated the historic direct sulfate forcing at much finer spatial resolutions than ever attempted before. Furthermore, we performed high-resolution chemistry simulations and saved monthly averaged oxidant fields, which will be used in subsequent simulations of sulfate aerosol formation and their radiative impact.

  16. High Resolution Rapid Revisits Insar Monitoring of Surface Deformation

    NASA Astrophysics Data System (ADS)

    Singhroy, V.; Li, J.; Charbonneau, F.

    2014-12-01

    Monitoring surface deformation on strategic energy and transportation corridors requires high resolution spatial and temporal InSAR images for mitigation and safety purposes. High resolution air photos, lidar and other satellite images are very useful in areas where the landslides can be fatal. Recently, radar interferometry (InSAR) techniques using more rapid revisit images from several radar satellites are increasingly being used in active deformation monitoring. The Canadian RADARSAT Constellation (RCM) is a three-satellite mission that will provide rapid revisits of four days interferometric (InSAR) capabilities that will be very useful for complex deformation monitoring. For instance, the monitoring of surface deformation due to permafrost activity, complex rock slide motion and steam assisted oil extraction will benefit from this new rapid revisit capability. This paper provide examples of how the high resolution (1-3 m) rapid revisit InSAR capabilities will improve our monitoring of surface deformation and provide insights in understanding triggering mechanisms. We analysed over a hundred high resolution InSAR images over a two year period on three geologically different sites with various configurations of topography, geomorphology, and geology conditions. We show from our analysis that the more frequent InSAR acquisitions are providing more information in understanding the rates of movement and failure process of permafrost triggered retrogressive thaw flows; the complex motion of an asymmetrical wedge failure of an active rock slide and the identification of over pressure zones related to oil extraction using steam injection. Keywords: High resolution, InSAR, rapid revisits, triggering mechanisms, oil extraction.

  17. High resolution nitrogen dioxide observations: retrieval, evaluation, and interpretation

    NASA Astrophysics Data System (ADS)

    Lamsal, L. N.; Janz, S. J.; Krotkov, N. A.; Pickering, K. E.; Kowalewski, M. G.; Loughner, C.; Spurr, R. J. D.; Crawford, J. H.

    2015-12-01

    The Airborne Compact Atmospheric Mapper (ACAM) deployed during the DISCOVER-AQ Maryland field campaign made hyperspectral remote sensing measurements in the 304-910 nm range allowing observations of several tropospheric pollutants including nitrogen dioxide (NO2) at an unprecedented spatial resolution of 1.5x0.75 km2. We apply the DOAS method, include high resolution information for surface reflectivity and vertical distributions of NO2 and aerosols, and account for temporal variation in atmospheric NO2 to retrieve lower tropospheric NO2 column. We compare NO2 from ACAM with observations from in-situ aircraft, ground-based PANDORA, and space-based OMI, and NO2 simulation from air quality models. The high resolution ACAM measurements offer not only new insights into our understanding of atmospheric composition and chemistry through observation of sub-sampling variability in typical satellite and model resolutions, but also opportunities for algorithm improvements for upcoming geostationary air quality missions.

  18. Comparing the cochlear spiral modiolar artery in type-1 and type-2 diabetes mellitus:a human temporal bone study.

    PubMed

    Kariya, Shin; Cureoglu, Sebahattin; Fukushima, Hisaki; Morita, Norimasa; Baylan, Muzeyyen Y; Maeda, Yukihide; Nishizaki, Kazunori; Paparella, Michael M

    2010-12-01

    This study examined whether pathological findings were present in cochlear vessels for patients with diabetes mellitus. Twenty-six temporal bones from 13 patients with type 1 diabetes mellitus and 40 temporal bones from 20 patients with type 2 diabetes mellitus were examined. Type 2 diabetic temporal bones were divided into 2 groups according to diabetic management (22 temporal bones with insulin therapy, and 18 with oral hypoglycemic drugs). Age-matched normal control temporal bones were also selected. The vessel wall thickness in the cochlear spiral modiolar artery was measured under a light microscope, and the vessel wall ratio (vessel wall thickness/outer diameter of the vessel x 100) was calculated. The vessel wall thickness and vessel wall ratio in type 1 diabetes mellitus were significantly greater than in normal controls. Type 2 diabetic patients with insulin therapy showed significantly greater vessel wall thickness and vessel wall ratios than controls. In type 2 diabetes mellitus, the vessel wall thickness and vessel wall ratio were greater in patients treated with insulin therapy than in those treated with oral hypoglycemic agents. Type 2 diabetic patients with insulin therapy showed an increased vessel wall thickness and vessel wall ratio compared to patients with type 1 diabetes mellitus. In conclusion, the cochlea in patients with diabetes mellitus shows circulatory disturbance compared to age-matched normal controls.

  19. Insertion forces and intracochlear trauma in temporal bone specimens implanted with a straight atraumatic electrode array.

    PubMed

    Mirsalehi, Marjan; Rau, Thomas S; Harbach, Lenka; Hügl, Silke; Mohebbi, Saleh; Lenarz, Thomas; Majdani, Omid

    2017-05-01

    The aim of the study was to evaluate insertion forces during manual insertion of a straight atraumatic electrode in human temporal bones, and post-implantation histologic evaluation of the samples to determine whether violation of intracochlear structures is related to insertion forces. In order to minimize intracochlear trauma and preserve residual hearing during cochlear implantation, knowledge of the insertion forces is necessary. Ten fresh frozen human temporal bones were prepared with canal wall down mastoidectomy. All samples were mounted on a one-axis force sensor. Insertion of a 16-mm straight atraumatic electrode was performed from different angles to induce "traumatic" insertion. Histologic evaluation was performed in order to evaluate intracochlear trauma. In 4 of 10 samples, dislocation of the electrode into scala vestibuli was observed. The mean insertion force for all 10 procedures was 0.003 ± 0.005 N. Insertion forces measured around the site of dislocation to scala vestibuli in 3 of 4 samples were significantly higher than insertion forces at the same location of the cochleae measured in samples without trauma (p < 0.04). Mean force during the whole insertion process of the straight atraumatic electrode is lower than reported by other studies using longer electrodes. Based on our study, insertion forces leading to basilar membrane trauma may be lower than the previously reported direct rupture forces.

  20. Wideband acoustic immittance measurements in assessing crimping status following stapedotomy: A temporal bone study.

    PubMed

    Wegner, Inge; Shahnaz, Navid; Grolman, Wilko; Bance, Manohar L

    2017-01-01

    To ascertain if wideband acoustic immitance (WAI) measurements are useful in assessing crimping status following stapedotomy. WAI measurements were obtained using the Mimosa Acoustics HearID system. Wideband chirp sound stimuli and a set of tone stimuli for nine frequencies between 0.2 and 6 kHz were used at 60 dB SPL. Five sets of measurements were performed on each temporal bone: mobile stapes, stapes fixation and stapedotomy followed by insertion of a tightly crimped, a loosely crimped and an uncrimped prosthesis. Eight fresh-frozen temporal bones were harvested from human cadaveric donors. At lower frequencies, up to 1 kHz, stapes fixation decreased absorbance. Compared to the baseline absorbance, absorbance with stapes fixation dropped by 6 to 17% in absolute terms from the baseline value (p = 0.027). Absorbance was not affected in higher frequencies (p = 0.725). Stapedotomy changed the absorbance curve significantly compared to the normal condition with an increase of absolute absorbance values by 6 to 36% around 0.25-1 kHz (p-value <0.01). The crimping conditions did not differ from one another (p = 0.555). WAI is not useful in distinguishing between tightly crimped, loosely crimped and uncrimped stapes prostheses following stapedotomy.

  1. Enhancement of temporal bone anatomy learning with computer 3D rendered imaging software.

    PubMed

    Venail, Frederic; Deveze, Arnaud; Lallemant, Benjamin; Guevara, Nicolas; Mondain, Michel

    2010-01-01

    To determine whether the use of 3D anatomical models is helpful to students and enhances their anatomical knowledge. First year undergraduate students on the speech therapy or hearing aid practitioner courses attended either a lecture alone or a lecture followed by a 3D anatomy based tutorial, the latter which was also attended by ENT residents. Participants who received the tutorial were free to use the 3D model on the university computers or on their home computer and were then asked to answer a satisfaction questionnaire. At the end of the first year examinations, the grades of the undergraduate students were compared between the lecture alone group and lecture plus tutorial group. Generally, all participants found this new tool interesting and user-friendly for the learning of temporal bone anatomy. However, most also considered the help of a teacher indispensable to guide them through the virtual dissection. First year undergraduate students who received the 3D anatomy tutorial performed significantly better during their end of year examination compared to those receiving a lecture alone, particularly concerning the more difficult questions. The 3D anatomical software, used in parallel with traditional teaching methods, such as lectures and cadaver dissection, appears to be a promising tool to improve student learning of temporal bone anatomy.

  2. Age-related primary cochlear neuronal degeneration in human temporal bones.

    PubMed

    Makary, Chadi A; Shin, Jennifer; Kujawa, Sharon G; Liberman, M Charles; Merchant, Saumil N

    2011-12-01

    In cases of acquired sensorineural hearing loss, death of cochlear neurons is thought to arise largely as a result of sensory-cell loss. However, recent studies of acoustic overexposure report massive degeneration of the cochlear nerve despite complete hair cell survival (Kujawa and Liberman, J Neurosci 29:14077-14085, 2009). To assess the primary loss of spiral ganglion cells (SGCs) in human ears, neuronal counts were performed in 100 temporal bones from 100 individuals, aged newborn to 100 years, selected to include only cases with a normal population of inner and outer hair cells. Ganglion cell counts declined at a mean rate of 100 cells per year of life. There were no significant gender or inter-aural differences, and a slight increase in degeneration in the basal turn re upper turns was not statistically significant. The age-related decline in SGCs was significantly less than that in prior studies that included ears with hair cell loss (Otte et al., Laryngoscope 88:1231-1246, 1978), but significantly more than for analogous data on vestibular ganglion cells in cases without vestibular hair cell loss (Velazquez-Villasenor et al., Ann Otol Rhinol Laryngol Suppl 181:14-19, 2000). The age-related decline in SGC counts may contribute to the well-known decline in hearing-in-noise performance, and the data will help in interpretation of histopathological findings from temporal bones with known otologic disease.

  3. Intracochlear Drug Delivery through the Oval Window in Fresh Cadaveric Human Temporal Bones

    PubMed Central

    Kang, Woo Seok; Nguyen, Kim; McKenna, Charles E.; Sewell, William F.; McKenna, Michael J.; Jung, David H.

    2015-01-01

    Hypothesis Drug delivered to the oval window can diffuse to the apex of the human cochlea. Background We have previously demonstrated that zoledronate, a nitrogen-containing bisphosphonate, can arrest the sensorineural hearing loss in cochlear otosclerosis. We have also shown that, in animals, delivery of bisphosphonate into the cochlea can dramatically increase delivery efficiency. Intracochlear drug delivery has the potential to increase local concentration of drug while decreasing the risk of systemic toxicity. In the present study, a fluorescently labeled bisphosphonate compound (6-FAM-ZOL) was introduced into the human cochlea through the oval window and its distribution within the temporal bone was quantified. Methods In three fresh human temporal bones, we introduced 6-FAM-ZOL via the oval window. We compared these specimens to control specimens treated with artificial perilymph alone. Specimens were then processed, embedded into methyl methacrylate, and ground to the mid-modiolar axis. We quantified the fluorescence in confocal images. Results We found 6-FAM-ZOL to be distributed up to the apical cochlear turn. In specimens treated with 6-FAM-ZOL, we identified a strong baso-apical gradient of fluorescent signal along the lateral cochlear wall and the modiolus both in the scala vestibuli and in the scala tympani. Conclusions Bisphosphonate introduced via the oval window in the human cochlea can be delivered up to the apical cochlear turn. Inter-scalar communication is likely to play an important role in determining patterns of drug delivery in the inner ear. PMID:26859540

  4. Practical aspects of high resolution esophageal manometry.

    PubMed

    Ruiz de León San Juan, Antonio; Ciriza de Los Ríos, Constanza; Pérez de la Serna Bueno, Julio; Canga Rodríguez-Valcárcel, Fernando; Estremera Arévalo, Fermín; García Sánchez, Raquel; Huamán Ríos, José Walter; Pérez Fernández, María Teresa; Santander Vaquero, Cecilio; Serra Pueyo, Jordi; Sevilla Mantilla, Concepción; Barba Orozco, Elisabeth; Bosque López, María José; Casabona Francés, Sergio; Carrión Bolorino, Silvia; Castillo Grau, Pilar; Delgado Aros, Silvia; Domínguez Carbajo, Ana Belén; Fernández Orcajo, Pilar; García-Lledó, Javier; Gigantó Tomé, Froilán; Iglesias Picazo, Rosa; Lacima Vidal, Gloria; López López, Pilar; Llabrés Rosselló, Magdalena; Mas Mercader, Pilar; Mego Silva, Marianela; Mendarte Barrenetxea, María Usua; Miliani Molina, Carlos; Oreja Arrayago, Milagros; Sánchez Ceballos, Francisco; Sánchez Prudencio, Sandra

    2017-02-01

    High resolution esophageal manometry (HRM) is currently under development as can be seen in the various Chicago classifications. In order to standardize criteria in certain practical aspects with limited scientific evidence, the First National Meeting for Consensus in High Resolution Manometry of the Spanish Digestive Motility Group took place, bringing together a wide group of experts. The proposals were based on a prior survey composed of 47 questions, an exhaustive review of the available literature and the experience of the participants. Methodological aspects relating to the poorly defined analysis criteria of certain new high resolution parameters were discussed, as well as other issues previously overlooked such as spontaneous activity or secondary waves. Final conclusions were drawn with practical applications.

  5. Pneumatization of the zygomatic process of temporal bone on computed tomograms

    PubMed Central

    Friedrich, Reinhard E.; Viezens, Liska; Grzyska, Ulrich

    2016-01-01

    Purpose: Zygomatic air cells (ZAC) are a variant of temporal bone pneumatization that needs no treatment. However, ZAC can have an impact on surgical procedures in the temporo-mandibular joint region. Recent reports suggest that computed tomography will disclose more ZAC than can be diagnosed on panoramic radiography. The aim of this study was to analyze ZAC prevalence on CT in a population that was not pre-selected by admission to a dental clinic. Furthermore, an extensive literature review was performed to assess the prevalence of ZAC and to address the impact of imaging technique on the definition of the item. Material and methods: Digitalized cranial CTs of 2007 patients were retrospectively analyzed. The Frankfort horizontal was used to define a ZAC on sagittal CTs. Results: In this study group, 806 were female (40.16%) and 1,201 were male (59.84%). Mean age was 49.96 years in the whole group (female: 55.83 years, male: 46.01 years). A ZAC was diagnosed in 152 patients (female: 66, male: 86). Unilateral ZAC surpasses bilateral findings (115 vs. 37 patients). ZAC were diagnosed in children 5 years of age and older. Sectional imaging techniques show a better visualization of the region of interest. However, presently an increase of ZAC prevalence attributable to imaging technique cannot conclusively be derived from the current literature. The normal finding of a ZAC on radiograms is a sharply defined homogenous transparent lesion restricted to the zygomatic process of the temporal bone that has no volume effect on the shape of the process. Conclusion: ZAC is an anatomical variant of the temporal bone that has come into focus of maxillofacial radiology due to its noticeable aspect on panoramic radiograms. The harmless variant can be expected in about one in thirteen individuals undergoing facial radiology. Panoramic radiograms appear to be sufficient to present ZAC of relevant size. However, in preparation for surgical procedures affecting the articular eminence

  6. The Effect of Piston Diameter in Stapedotomy for Otosclerosis: A Temporal Bone Model.

    PubMed

    Wegner, Inge; Eldaebes, Mostafa M A S; Landry, Thomas G; Grolman, Wilko; Bance, Manohar L

    2016-12-01

    The use of larger-diameter pistons in stapedotomy leads to better hearing outcomes compared with the use of smaller-diameter pistons. There is an interaction between stapes piston diameter and fenestration diameter. Otosclerosis can be treated surgically by removing part of the stapes and bypassing the stapes footplate with a prosthesis. Available piston shaft diameters range between 0.3 and 0.8 mm. There has been a tendency toward the use of smaller-diameter pistons, because of a suspected decreased risk of cochlear trauma and subsequent sensorineural hearing loss (SNHL) with smaller pistons. However, mathematical models, temporal bone studies, and clinical studies suggest that the use of larger-diameter pistons is associated with better hearing outcomes. Three fresh-frozen, non-pathologic temporal bones were harvested from human cadaveric donors. Acoustic stimuli in the form of pure tones from 250 to 8000 Hz were generated at 110 dB sound pressure level. A total of 16 frequencies in a 1/3-octave series were used. Stapes and round window velocities in response to the acoustic stimuli were measured at multiple equally spaced points covering the stapes footplate and round window using a scanning laser Doppler interferometry system. Eight sets of measurements were performed in each temporal bone: 1) normal condition (mobile stapes), 2) stapes fixation and stapedotomy followed by insertion of 3) a 0.4-mm-diameter piston in a 0.5-mm-diameter fenestration, 4) a 0.4-mm-diameter piston in a 0.7-mm-diameter fenestration, 5) a 0.4-mm-diameter piston in a 0.9-mm-diameter fenestration, 6) a 0.6-mm-diameter piston in a 0.7-mm-diameter fenestration, 7) a 0.6-mm-diameter piston in a 0.9-mm-diameter fenestration, and 8) a 0.8-mm-diameter piston in a 0.9-mm-diameter fenestration. At midrange frequencies, between 500 and 4000 Hz, round window velocities increased by 2 to 3 dB when using a 0.6-mm-diameter piston compared with a 0.4-mm-diameter piston. Using a 0.8-mm

  7. Vestibular System Changes in Sudden Deafness With and Without Vertigo: A Human Temporal Bone Study

    PubMed Central

    Inagaki, Taro; Cureoglu, Sebahattin; Morita, Norimasa; Terao, Kyoichi; Sato, Teruyuki; Suzuki, Mamoru; Paparella, Michael M.

    2013-01-01

    Objective To investigate the vestibular system changes in sudden deafness with vertigo (SDwV) and sudden deafness without vertigo (SDwoV) and the cause of persistent canal paresis (CP) in SDwV patients. Study Design Retrospective study. Materials and Methods Four temporal bones from the affected ear in 4 patients with unilateral sudden deafness (SD), 2 SDwV and 2 SDwoV, were selected. Four contralateral temporal bones with normal-hearing ears were defined as the control. Morphologic findings of the labyrinth, the number of Scarpa’s ganglion cells, and the density of vestibular hair cells were investigated in all temporal bones. Clinical data and the results of vestibular tests of 11 patients with unilateral SD, as a separate group, also were investigated. Results Atrophic change of the organ of Corti, tectorial membrane, and stria vascularis in cochlea, and deposits and atrophic otoconial membrane in vestibular sense organs were seen on affected ears more than control ears. The density of Type I hair cells seemed to decrease on the saccular macula and the posterior semicircular canal crista on affected ears, and there was no remarkable difference between SDwV and SDwoV. In 1 patient with SDwoV who died 10 months after the onset of SD, there were large amount of deposits on the cupula, the atrophied otoconial membrane was peeling off from the saccular macula, and the saccular membrane collapsed to the saccular macula in the affected ear. In the clinical data, all SDwV who were examined within 2 years from the onset had CP, and all SDwV had profound hearing loss. Conclusion There is no remarkable difference between SDwV and SDwoV in the number of Scarpa’s ganglion cells and the density of vestibular hair cells. The damage of the extracellular superstructure is seen in SD with or without vertigo. The damage of extracellular superstructure is potentially one of the causes of persistent CP in patients with SD. PMID:22872175

  8. Pediatric temporal bone fractures: current trends and comparison of classification schemes.

    PubMed

    Dunklebarger, Joshua; Branstetter, Barton; Lincoln, Anne; Sippey, Megan; Cohen, Michael; Gaines, Barbara; Chi, David

    2014-03-01

    1) Characterize the current presentation of pediatric temporal bone fractures, 2) compare two classification schemes for temporal bone fractures and illustrate complications in each fracture type. Retrospective medical record review. Tertiary-care, academic children's hospital. All children presenting from 1999 to 2009 with CT-proven temporal bone fracture and audiology examination with follow-up. All CT scans were reinterpreted by a dedicated head and neck radiologist. All fractures were characterized as otic capsule sparing (OCS) or otic capsule violating (OCV), as well as transverse (T) or longitudinal (L). CT findings, mechanisms of injury, sensorineural hearing loss (SNHL), conductive hearing loss (CHL), and facial nerve injury (FNI). Seventy-one children met inclusion criteria. Fifty-four (76%) children had longitudinal fractures versus 17 (24%) with transverse fractures. Sixty-four (90%) had OCS versus 7 (10%) with OCV. The otic capsule was involved in 7.4% of longitudinal fractures and 17.6% of transverse fractures. Eleven (15%) had facial weakness, 72% of whom had a visualized fracture through the facial nerve course. SNHL was detected in 14 (20%) patients and CHL in 17(23.9%). All patients with fractures classified as both transverse and OCV had SNHL. The OCS versus OCV and T versus L classification schemes were directly compared for statistical significance in predicting SNHL, CHL, and FNI using the Fisher's exact test. Both OCS/OCV and T/L were predictors of SNHL (P = .0025 and P = .0143, respectively), but the OCS/OCV scheme was more accurate. Neither classification significantly predicted CHL or FNI (P = .787 versus .825; P = .705 vs. .755). In this pediatric series, approximately 75% of the fractures are longitudinal and 25% are transverse. The otic capsule is spared in 90% and violated in 10%. Both OCS/OCV and L/T classification schemes predict SNHL, but the OCV/OCS scheme is more accurate in this prediction. Although the negative predictive value

  9. A high-resolution tungstate membrane label

    SciTech Connect

    Hainfeld, J.F.; Quaite, F.E. ); Lipka, J.J. )

    1990-01-01

    A new class of membrane labels was synthesized which contain a tungstate cluster (having 11 tungsten atoms) and an aliphatic organo-tin moiety with various chain lengths (C{sub 4}, C{sub 8}, C{sub 12}, C{sub 18}, C{sub 22}). These molecules were found to insert into synthetic phospholipid vesicles and biological membranes (human red blood cell membranes). The tungstate clusters can be individually visualized in the high resolution STEM or seen en mass in thin-sectioned labeled membranes in the CTEM. These new labels should provide a means for direct high-resolution imaging of lipid-phase systems.

  10. RAPID DAMAGE ASSESSMENT FROM HIGH RESOLUTION IMAGERY

    SciTech Connect

    Vijayaraj, Veeraraghavan; Bright, Eddie A; Bhaduri, Budhendra L

    2008-01-01

    Disaster impact modeling and analysis uses huge volumes of image data that are produced immediately following a natural or an anthropogenic disaster event. Rapid damage assessment is the key to time critical decision support in disaster management to better utilize available response resources and accelerate recovery and relief efforts. But exploiting huge volumes of high resolution image data for identifying damaged areas with robust consistency in near real time is a challenging task. In this paper, we present an automated image analysis technique to identify areas of structural damage from high resolution optical satellite data using features based on image content.

  11. Closure of the middle ear with special reference to the development of the tegmen tympani of the temporal bone

    PubMed Central

    Rodríguez-Vázquez, José Francisco; Murakami, Gen; Verdugo-López, Samuel; Abe, Shin-ichi; Fujimiya, Mineko

    2011-01-01

    Closure of the middle ear is believed to be closely related to the evolutionary development of the mammalian jaw. However, few comprehensive descriptions are available on fetal development. We examined paraffin-embedded specimens of 20 mid-term human fetuses at 8–25 weeks of ovulation age (crown-rump length or CRL, 38–220 mm). After 9 weeks, the tympanic bone and the squamous part of the temporal bone, each of which was cranial or caudal to Meckel's cartilage, grew to close the lateral part of the tympanosquamosal fissure. At the same time, the cartilaginous tegmen tympani appeared independently of the petrous part of the temporal bone and resulted in the petrosquamosal fissure. Subsequently, the medial part of the tympanosquamosal fissure was closed by the descent of a cartilaginous inferior process of the tegmen tympani. When Meckel's cartilage changed into the sphenomandibular ligament and the anterior ligament of the malleus, the inferior process of the tegmen tympani interposed between the tympanic bone and the squamous part of the temporal bone, forming the petrotympanic fissure for the chorda tympani nerve and the discomalleolar ligament. Therefore, we hypothesize that, in accordance with the regression of Meckel's cartilage, the rapidly growing temporomandibular joint provided mechanical stress that accelerated the growth and descent of the inferior process of the tegmen tympani via the discomalleolar ligament. The usual diagram showing bony fissures around the tegmen tympani may overestimate the role of the tympanic bone in the fetal middle-ear closure. PMID:21477146

  12. Correlation Between Histologic and Radiographic Reconstruction of Intracochlear Electrode Position in Human Temporal Bones

    PubMed Central

    O’Malley, Jennifer T.; Burgess, Barbara J.; Zhu, MengYu; Curtin, Hugh D.; Nadol, Joseph B.

    2014-01-01

    In our laboratory, human temporal bone specimens from patients who in life have undergone cochlear implantation are routinely processed with the implant in situ, embedded in araldite, sectioned at 20 μm and serially photographed during cutting, stained with toluidine blue and mounted on glass slides. From the images, 2D and 3D reconstructions can be made and a very accurate implant insertion depth can be calculated from the 3D reconstructions. However, this method precludes subsequent special stains and further molecular investigations of the tissue including proteomics and immunostaining which is now possible with celloidin embedded tissue. In this study, we correlated measurement of the implant array insertion depth calculated from histologic 3D reconstruction with that measured from 3D radiologic multiplanar reconstruction. Four human temporal bones with cochlear implants underwent post-fixation pre-processing CT imaging with a Siemens Somatom Sensation Scanner. The CT scans from these four bones were downloaded into the Voxar software application, reformatted using the multiplanar reconstruction tool, viewed in three dimensions and measurements of intracochlear insertion lengths of the implants were obtained. The bones were processed routinely for in situ araldite embedding, serial images were made of the block during sectioning, post-processed using PV-Wave® software, aligned with Amira® software, and used to create histologic 3D reconstructions. From these 3D reconstructions, the insertion depth of the electrode array was mathematically calculated. The range of insertion depths was 15.9 mm (case #1) to 26.6 mm (case #4). The two methods, radiographic multiplanar reconstruction and 3D reconstruction, differed by 0.4 – 0.9%. This provides confidence that important localization information about the electrode in situ can be gleaned from CT scans, thereby allowing us to extract the implants prior to processing for celloidin embedment and allow further

  13. High-resolution secondary reconstructions with the use of flat panel CT in the clinical assessment of patients with cochlear implants.

    PubMed

    Pearl, M S; Roy, A; Limb, C J

    2014-06-01

    Radiologic assessment of cochlear implants can be limited because of metallic streak artifacts and the high attenuation of the temporal bones. We report on 14 patients with 18 cochlear implants (17 Med-El standard 31.5-mm arrays, 1 Med-El medium 24-mm array) who underwent flat panel CT with the use of high-resolution secondary reconstruction techniques. Flat panel CT depicted the insertion site, cochlear implant course, and all 216 individual electrode contacts. The calculated mean angular insertion depth for standard arrays was 591.9° (SD = 70.9; range, 280°). High-resolution secondary reconstructions of the initial flat panel CT dataset, by use of a manually generated field of view, Hounsfield unit kernel type, and sharp image characteristics, provided high-quality images with improved spatial resolution. Flat panel CT is a promising imaging tool for the postoperative evaluation of cochlear implant placement.

  14. Design and test of a High-Resolution EUV Spectroheliometer

    NASA Technical Reports Server (NTRS)

    Berger, Thomas E.; Timothy, J. G.; Walker, Arthur B. C., Jr.; Kirby, Helen; Morgan, Jeffrey S.; Jain, Surendra K.; Saxena, Ajay K.; Bhattacharyya, Jagadish C.; Huber, Martin C. E.; Tondello, Giuseppe

    1992-01-01

    The HiRES High-Resolution EUV Spectroheliometer is a sounding rocket instrument yielding very high spatial, spectral, and temporal resolution images of the solar outer atmosphere, on the basis of a 45-cm Gregorian telescope feeding a normal-incidence stigmatic EUV spectrometer with imaging multianode microchannel-array detector system, as well as an IR spectrometer with imaging CCD detector system. Attention is given to the expected performance of this system, including the effects of vibrational misalignments due to the sounding rocket flight environment.

  15. High Resolution Modeling of Tropical Cyclones Using Rare Event Simulation

    NASA Astrophysics Data System (ADS)

    Plotkin, D. A.; Abbot, D. S.; Weare, J.

    2014-12-01

    Tropical cyclones (TCs) present a challenge to modeling using general circulation models (GCMs) because they involve processes and structures that are too fine for GCMs to resolve. TCs have fine structures - e.g. the eye, eyewall, and rain bands - with length scales on the order of 10 km, while GCMs have typical resolutions on the order of 50-100 km. High resolution GCM runs that are sufficiently long to exhibit multiple TCs can be prohibitively computationally expensive. Thus, while GCMs exhibit TC-like vortices with similar spatial and temporal frequencies to observed TCs, the ability of GCMs to reproduce fine TC structures remains largely untested. In this study, we use recently developed rare event analysis and simulation methods to selectively simulate TCs under GCMs at very high resolution. These rare event simulation methods have been developed mostly in the context of computational chemistry, but are broadly applicable. They allow (either by careful manipulation of the model or by selection of trajectories) direct and detailed interrogation of the event of interest without introducing error and without the need to simulated for long periods of time to see the event. By creating targeted, high resolution GCM simulations with many TCs, we hope to determine whether or not GCMs can capture fine TC structures such as eyewalls and individual rain bands.

  16. Concurrent necrotising otitis externa and adenocarcinoma of the temporal bone: a diagnostic challenge

    PubMed Central

    Foden, Neil; Burgess, Christopher; Damato, Stephen; Ramsden, James

    2013-01-01

    We present a case of an 81-year-old man who was diagnosed with a necrotising (malignant) otitis externa (NOE). Initial biopsies from the external auditory canal showed scanty squamous epithelium but no evidence of malignancy. Despite an initial improvement on intravenous antibiotics and subsequent discharge from hospital, the patient returned with worsening otalgia. Following readmission to the hospital, intravenous antibiotics were restarted. Despite this, the patient developed a lower motor neurone palsy of cranial nerve VII on the ipsilateral side of the pain. He was taken to the theatre for an exploration of the left mastoid with further biopsies. Adenocarcinoma was diagnosed histologically and the patient was started on palliative radiotherapy. This case adds to the known literature on metastatic disease in the temporal bone and highlights the need to exclude malignancy in cases of NOE. PMID:24197806

  17. Concurrent necrotising otitis externa and adenocarcinoma of the temporal bone: a diagnostic challenge.

    PubMed

    Foden, Neil; Burgess, Christopher; Damato, Stephen; Ramsden, James

    2013-11-06

    We present a case of an 81-year-old man who was diagnosed with a necrotising (malignant) otitis externa (NOE). Initial biopsies from the external auditory canal showed scanty squamous epithelium but no evidence of malignancy. Despite an initial improvement on intravenous antibiotics and subsequent discharge from hospital, the patient returned with worsening otalgia. Following readmission to the hospital, intravenous antibiotics were restarted. Despite this, the patient developed a lower motor neurone palsy of cranial nerve VII on the ipsilateral side of the pain. He was taken to the theatre for an exploration of the left mastoid with further biopsies. Adenocarcinoma was diagnosed histologically and the patient was started on palliative radiotherapy. This case adds to the known literature on metastatic disease in the temporal bone and highlights the need to exclude malignancy in cases of NOE.

  18. A temporal bone surgery simulator with real-time feedback for surgical training.

    PubMed

    Wijewickrema, Sudanthi; Ioannou, Ioanna; Zhou, Yun; Piromchai, Patorn; Bailey, James; Kennedy, Gregor; O'Leary, Stephen

    2014-01-01

    Timely feedback on surgical technique is an important aspect of surgical skill training in any learning environment, be it virtual or otherwise. Feedback on technique should be provided in real-time to allow trainees to recognize and amend their errors as they occur. Expert surgeons have typically carried out this task, but they have limited time available to spend with trainees. Virtual reality surgical simulators offer effective, repeatable training at relatively low cost, but their benefits may not be fully realized while they still require the presence of experts to provide feedback. We attempt to overcome this limitation by introducing a real-time feedback system for surgical technique within a temporal bone surgical simulator. Our evaluation study shows that this feedback system performs exceptionally well with respect to accuracy and effectiveness.

  19. Chondrosarcoma of the temporal bone. Diagnosis and treatment of 13 cases and review of the literature

    SciTech Connect

    Coltrera, M.D.; Googe, P.B.; Harrist, T.J.; Hyams, V.J.; Schiller, A.L.; Goodman, M.L.

    1986-12-15

    Chondrosarcoma of the temporal bone is a rare lesion. Clinically it has been confused with multiple sclerosis, glomus jugulare tumors, meningioma, and chordomas. The cranial nerve palsies frequently observed with the tumors are related to the anatomic locations of the tumors. Thirteen patients with this entity are presented and the eleven other cases in the literature are reviewed. Histologically the tumors are low grade and exhibit myxoid features. The myxoid features must be differentiated from chordoma and chondroid chordoma. The tumor locations preclude surgical excision and conventional radiation therapy can cause unacceptable neurologic sequelae. Proton beam therapy has been effective in short-term results and appears capable of avoiding serious neurologic side effects.

  20. Photoacoustic effects of carbon dioxide lasers in stapes surgery: quantification in a temporal bone model.

    PubMed

    Gardner, Edward K; Dornhoffer, John; Ferguson, Scott

    2002-11-01

    The use of the CO2 laser in stapes surgery creates sound waves that could damage hearing. BACKGROUND The application of a laser to any medium has absorption, reflection, and thermal effects. To date, the majority of research on the safety of CO2 laser stapedotomy has focused on the thermal effects of the laser alone. Because of the properties of the CO2 laser, its absorption also presents some risk to the inner ear. This absorbed energy can be converted to photoacoustic or photochemical effects. The goal of this paper is to measure these photoacoustic effects (sounds) produced by the CO2 laser. Using a variety of settings, a Sharplan 150 XJ Laser and a Contour model Erbium:YAG laser were applied to the oval window of human temporal bones. Perilymph was simulated by fixing the temporal bone in a normal saline bath. Photoacoustic waves were measured by a hydrophone 2 mm beneath the oval window. Measurements were made with and without a simulated tissue seal over the window. No detectable sounds were created below 4 watts (continuous mode) or 60 mJ (superpulse mode). Above those settings, intensities of 90 dB sound pressure level and higher were detected when the laser was applied directly to the perilymph. With the tissue seal in place, no detectable sounds were identified. The accuracy of this model was confirmed by comparing these results with previously published results using the Erbium:YAG laser. Below 4 watts in continuous wave mode and below 60 mJ in superpulse mode, any sound generated by the laser is small. Above these thresholds, however, impact sounds are produced that could result in threshold shifts with repeated applications.

  1. Self-crimping superelastic nitinol prosthesis and malleostapedotomy: a temporal bone study.

    PubMed

    Magliulo, Giuseppe

    2013-02-01

    The aim of this study was to compare the results of application of 2 types of superelastic nitinol prostheses. Temporal bones study with planned data collection. Tertiary referral center. Malleostapedotomy was performed in 15 human temporal bones implanting 3 different prostheses: manually crimping polytetrafluoroethylene (MC-PTFE) piston, nitinol self-crimping polytetrafluoroethylene (SC-PTFE) piston, and a modified nitinol self-crimping polytetrafluoroethylene (mSC-PTFE) piston. The first 2 have a diameter of 0.4 mm and length of 7 mm, whereas the mSC-PTFE piston has a diameter of 0.4 mm but a length of 7.75 mm. We evaluated various parameters of prosthesis attachment-that is, the time for implantation of SC and mSC nitinol loop pistons and the MC platinum loop piston, the quality of attachment of the prostheses to the malleus, their positions with respect to the center of the stapes footplate, and the protrusion of the piston into the vestibule. The mSC-PTFE superelastic nitinol prosthesis showed a statistically significant difference in mean operation time (mSC vs SC, P < .0001; SC vs MC, P < .0001; mSC vs MC, P < .0001). The protrusion of the piston into the vestibule was highly reproducible in all 3 prostheses. Because of its greater length, the mSC-PTFE allows for management of the most varied anatomical conditions. At the same time, its self-crimping nature prevents the risk of distortion of the prosthesis by the crimping process and reduces the operation time in combination with standardized bending of the prosthesis shaft.

  2. High-resolution two dimensional advective transport

    USGS Publications Warehouse

    Smith, P.E.; Larock, B.E.

    1989-01-01

    The paper describes a two-dimensional high-resolution scheme for advective transport that is based on a Eulerian-Lagrangian method with a flux limiter. The scheme is applied to the problem of pure-advection of a rotated Gaussian hill and shown to preserve the monotonicity property of the governing conservation law.

  3. Titania High-Resolution Color Composite

    NASA Image and Video Library

    1996-01-29

    This high-resolution color composite of Titania was made from NASA Voyager 2 images taken Jan. 24, 1986, as the spacecraft neared its closest approach to Uranus. A large, trenchlike feature is seen near the terminator. http://photojournal.jpl.nasa.gov/catalog/PIA00036

  4. A High-Resolution Stopwatch for Cents

    ERIC Educational Resources Information Center

    Gingl, Z.; Kopasz, K.

    2011-01-01

    A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of a sound card. Dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free…

  5. A High-Resolution Stopwatch for Cents

    ERIC Educational Resources Information Center

    Gingl, Z.; Kopasz, K.

    2011-01-01

    A very low-cost, easy-to-make stopwatch is presented to support various experiments in mechanics. The high-resolution stopwatch is based on two photodetectors connected directly to the microphone input of a sound card. Dedicated free open-source software has been developed and made available to download. The efficiency is demonstrated by a free…

  6. High-Resolution Global Soil Moisture Map

    NASA Image and Video Library

    2015-05-19

    High-resolution global soil moisture map from NASA SMAP combined radar and radiometer instruments, acquired between May 4 and May 11, 2015 during SMAP commissioning phase. The map has a resolution of 5.6 miles (9 kilometers). The data gap is due to turning the instruments on and off during testing. http://photojournal.jpl.nasa.gov/catalog/PIA19337

  7. Sensorineural hearing loss: there is no correlation with isolated dysplasia of the lateral semi-circular canal on temporal bone CT.

    PubMed

    Yamashita, Koji; Yoshiura, Takashi; Hiwatashi, Akio; Tuvshinjargal, Dashjamts; Kamano, Hironori; Inoguchi, Takashi; Honda, Hiroshi

    2011-03-01

    Inner ear malformations may cause sensorineural hearing loss (SNHL). However, the correlation between the small lateral semi-circular canal (LSCC) and SNHL is controversial. To determine whether there is a correlation between the two using CT-based measurement. We retrospectively reviewed the high-resolution CT images of the temporal bone obtained from consecutive patients. A total 136 ears of 68 patients (25 men and 43 women; age range 20-85 years, mean 49.8 years) were included in this study. Patients who were clinically suspected to have otosclerosis were also excluded. Two radiologists independently measured the width and cross-sectional area of the bony island of LSCC. We evaluated the correlation between LSCC bone island width or cross-sectional area and hearing level in all cases using Pearson correlation co-efficients. In addition, we compared hearing levels among the patient group with normal-sized LSCC (≧mean-SD), small LSCC ( 0.05). No significant difference in hearing levels were found among groups of the normal-sized, small and very small LSCC (P > 0.05). We conclude that there is no correlation between isolated small LSCC and SNHL.

  8. Temporal bone borehole accuracy for cochlear implantation influenced by drilling strategy: an in vitro study.

    PubMed

    Kobler, Jan-Philipp; Schoppe, Michael; Lexow, G Jakob; Rau, Thomas S; Majdani, Omid; Kahrs, Lüder A; Ortmaier, Tobias

    2014-11-01

    Minimally invasive cochlear implantation is a surgical technique which requires drilling a canal from the mastoid surface toward the basal turn of the cochlea. The choice of an appropriate drilling strategy is hypothesized to have significant influence on the achievable targeting accuracy. Therefore, a method is presented to analyze the contribution of the drilling process and drilling tool to the targeting error isolated from other error sources. The experimental setup to evaluate the borehole accuracy comprises a drill handpiece attached to a linear slide as well as a highly accurate coordinate measuring machine (CMM). Based on the specific requirements of the minimally invasive cochlear access, three drilling strategies, mainly characterized by different drill tools, are derived. The strategies are evaluated by drilling into synthetic temporal bone substitutes containing air-filled cavities to simulate mastoid cells. Deviations from the desired drill trajectories are determined based on measurements using the CMM. Using the experimental setup, a total of 144 holes were drilled for accuracy evaluation. Errors resulting from the drilling process depend on the specific geometry of the tool as well as the angle at which the drill contacts the bone surface. Furthermore, there is a risk of the drill bit deflecting due to synthetic mastoid cells. A single-flute gun drill combined with a pilot drill of the same diameter provided the best results for simulated minimally invasive cochlear implantation, based on an experimental method that may be used for testing further drilling process improvements.

  9. Ultrasound-induced hyperthermia for the spatio-temporal control of gene expression in bone repair

    NASA Astrophysics Data System (ADS)

    Wilson, Christopher; Padilla, Frédéric; Zhang, Man; Vilaboa, Nuria; Kripfgans, Oliver; Fowlkes, Brian; Franceschi, Renny

    2012-10-01

    Spatial and temporal control over the expression of growth/differentiation factors is of great interest for regeneration of bone, but technologies capable of providing tight and active control over gene expression remain elusive. We propose the use of focused ultrasound for the targeted activation of heat shock-sensitive expression systems in engineered bone. We report in vitro results with cells that express firefly luciferase (fLuc) under the control of a heat shock protein promoter. Cells were embedded in fibrin scaffolds and exposed to focused ultrasound, using a custom 3.3MHz transducer (focal length 4", f-number 1.33", focal dimension 1.2mm lateral FWHM) in CW mode for 2-20 minutes at intensities ISPTA=120-440 W/cm2. The kinetics of ultrasound-mediated activation of the cells was compared with that of strictly thermal activation. Bioluminescence imaging revealed fLuc expression in an area ≥2.5mm in diameter at the position of the ultrasound focus, and the diameter and intensity of the signal increased with the amplitude of the acoustic energy. We also found that ultrasound activated fLuc expression with substantially shorter exposures than thermal activation. Our results demonstrate the potential for focused ultrasound to selectively activate the expression of a gene of interest in an engineered tissue and suggest that focused ultrasound activates the heat shock pathway by a combination of thermal and non-thermal mechanisms.

  10. Topographical anatomy and measurements of selected parameters of the rat temporal bone.

    PubMed

    Wysocki, J

    2008-05-01

    On the basis of dissection of 24 bones of 12 black rats a systematic anatomical description was made and measurements of selected size parameters of the temporal bone were taken. Besides the main air space in the middle ear, the tympanic bulla, there are also additional air cells, namely the anterior and posterior epitympanic recesses, containing the head of the malleus and the body of the incus. On the side of the epitympanic recesses the following are easily accessible: the malleus head and the core of the incus, the superior and lateral semicircular canals and the facial nerve. On the side of the ventral tympanic bulla it is easy access to both windows and the cochlea. The semicircular canals are relatively large, the lateral canal being the largest and the posterior the smallest. The length of the spiral canal of the cochlea does not exceed 11 mm. It is worth mentioning that both the vertical and horizontal dimensions of the scala vestibuli and scala tympani do not even exceed 0.7 mm in the basal turn, and are significantly decreased to tenths of a millimetre in further turns. This needs to be taken into consideration during all experiments requiring the introduction of examining instruments into the cochlear scala.

  11. Experimental Assessment of the Performance of an Electromagnetic Hearing Aid in Human Temporal Bones

    NASA Astrophysics Data System (ADS)

    Hamanishi, Shinji; Koike, Takuji; Chien, Wade; Ravicz, Michael E.; Rosowski, John J.; Merchant, Saumil N.; Kobayashi, Toshimitsu; Wada, Hiroshi

    To circumvent some of the problems inherent in conventional hearing aids such as low gain at high frequencies due to acoustic feedback, discomfort in occlusion of the external ear canal and so on, implantable hearing aids have been developed over the past two decades. The most prominent feature of implantable hearing aids is that a transducer is directly coupled to the one of the middle-ear ossicles. However, since invasive surgery is necessary for implantation of these hearing aids, they have not as yet been widely employed. We therefore constructed a prototype of a non-implantable hearing aid which is mainly composed of a microphone amplifier system and an electromagnetic transducer developed in our previous study. It can generate an excitation force to vibrate the ossicles by a coil adhered to the tympanic membrane. In this study, the excitation force generated by this hearing aid was evaluated using human temporal bones. The best result of experiments using three bones indicates that the newly developed hearing aid can generate an excitation force of more than 80dB SPL in terms of sound pressure at frequencies between 0.8 and 3.2kHz.

  12. Experimental Simulation of Clinical Borderline Situations in Temporal Bone Specimens After Ossiculoplasty.

    PubMed

    Jakob, Till F; Kromeier, Jan; Baumann, Tobias; Pfeiffer, Jens; Neudert, Marcus; Laszig, Roland; Zahnert, Thomas; Offergeld, Christian

    2017-06-30

    One reason for insufficient hearing improvement with a distinct air-bone gap after ossiculoplasty with implantation of partial or total ossicular replacement prostheses can be the dislocation or minimal shifting of the prosthesis. The aim of this study was the simulation of common clinical borderline situations with minimal shifting of the prosthesis in temporal bone specimens after ossiculoplasty. It was furthermore the goal to identify these specific situations through imaging by cone beam computed tomography (cbCT) and direct visual inspection using the operation microscope. Additionally, the functional status was evaluated using laser-Doppler vibrometry (LDV). We used a total of four temporal bone specimens for this study. A reconstruction with a partial ossicular replacement prostheses was performed in three specimens and with a total ossicular replacement prostheses in one specimen, with good initial acoustic properties. Subsequently, one specific type of prosthesis failure was simulated in each specimen, respectively, by minimally shifting, tilting, or bending the prostheses from their initial positions. These changes were introduced step-by-step until a borderline situation just short of complete acoustic decoupling was reached. Each step was examined using both LDV and cbCT and observed through the operation microscope. LDV was able to quantify the mechanic function of the ossicular chain after most of the manipulation steps by demonstrating the effect of any shifting of the prosthesis on the middle ear transfer function. However, in some situations, the middle ear transfer function was better with a visually more advanced failure of the prosthesis. In addition, cbCT showed most of the steps with excellent resolution and was able to delineate changes in soft tissue (e.g., cartilage covering). cbCT seems to be a promising imaging technique for middle ear problems. As cbCT and LDV exhibited slightly different advantages and disadvantages regarding the

  13. Cochlear Implantation through the Middle Fossa Approach: A Review of Related Temporal Bone Studies and Reported Cases.

    PubMed

    Lesser, Juan Carlos Cisneros; Brito Neto, Rubens Vuono de; Martins, Graziela de Souza Queiroz; Bento, Ricardo Ferreira

    2017-01-01

    Introduction Middle fossa approach has been suggested as an alternative for patients in whom other routes of electrode insertion are contraindicated. Even though there are temporal bone studies about the feasibility of introducing the cochlear implant through the middle fossa, until now, very few studies have described results when cochlear implant surgery is done through this approach. Objective The objective of this study is to review a series of temporal bone studies related to cochlear implantation through the middle fossa and the results obtained by different surgical groups after cochlear implantation through this approach. Data Sources PubMed, MD consult and Ovid-SP databases. Data Synthesis A total of 8 human cadaveric temporal bone studies and 6 studies reporting cochlear implant surgery through the middle fossa approach met the inclusion criteria. Temporal bone studies show that it is feasible to perform cochlear implantation through this route. So far, only two surgical groups have performed cochlear implantation through the middle fossa with a total of 15 implanted patients. One group entered the cochlea in the most upper part of the basal turn, inserting the implant in the direction of the middle and apical turns; meanwhile, the other group inserted the implant in the apical turn directed in a retrograde fashion to the middle and basal turns. Results obtained in both groups were similar. Conclusions The middle fossa approach is a good alternative for cochlear implantation when other routes of electrode insertion are contraindicated.

  14. Systemic Lupus Erythematosus and hearing disorders: Literature review and meta-analysis of clinical and temporal bone findings.

    PubMed

    Di Stadio, Arianna; Ralli, Massimo

    2017-01-01

    Objective This literature review and meta-analysis was performed to evaluate the correlations among hearing and vestibular clinical symptoms, temporal bone findings, and pathological mechanisms in patients with systemic lupus erythematosus (SLE). Study design Relevant papers in the literature were retrospectively reviewed. Clinical hearing aspects in patients with SLE and relevant temporal bone studies in the same field were analyzed. Methods PubMed and Google Scholar searches were performed using the following keywords: "auto-immune disease," "systemic lupus erythematosus (SLE)," "hearing loss," "temporal bone study," "vertigo," "dizziness," "tinnitus," "ear symptoms," "treatment," "diagnosis," "symptoms," "etiopathogenesis," "Wegener granulomatosis," "Sjogren," "polyarteritis nodosa," "Cogan syndrome," and "granulomatosis." Also included were reviews in which the following terms were present: "SLE," "temporal bone," and "hearing symptoms." Review and conclusion This literature review and meta-analysis focused on the pathological mechanisms through which SLE can damage inner ear structures and determinate hearing and vestibular symptoms. The main mechanisms involved in inner ear damage include the autoimmune response, deposition of immune complexes in the vessels and, to a lesser extent, cytotoxic damage.

  15. Cochlear Implantation through the Middle Fossa Approach: A Review of Related Temporal Bone Studies and Reported Cases

    PubMed Central

    Lesser, Juan Carlos Cisneros; Brito Neto, Rubens Vuono de; Martins, Graziela de Souza Queiroz; Bento, Ricardo Ferreira

    2016-01-01

    Introduction Middle fossa approach has been suggested as an alternative for patients in whom other routes of electrode insertion are contraindicated. Even though there are temporal bone studies about the feasibility of introducing the cochlear implant through the middle fossa, until now, very few studies have described results when cochlear implant surgery is done through this approach. Objective The objective of this study is to review a series of temporal bone studies related to cochlear implantation through the middle fossa and the results obtained by different surgical groups after cochlear implantation through this approach. Data Sources PubMed, MD consult and Ovid-SP databases. Data Synthesis A total of 8 human cadaveric temporal bone studies and 6 studies reporting cochlear implant surgery through the middle fossa approach met the inclusion criteria. Temporal bone studies show that it is feasible to perform cochlear implantation through this route. So far, only two surgical groups have performed cochlear implantation through the middle fossa with a total of 15 implanted patients. One group entered the cochlea in the most upper part of the basal turn, inserting the implant in the direction of the middle and apical turns; meanwhile, the other group inserted the implant in the apical turn directed in a retrograde fashion to the middle and basal turns. Results obtained in both groups were similar. Conclusions The middle fossa approach is a good alternative for cochlear implantation when other routes of electrode insertion are contraindicated. PMID:28050216

  16. Use of the LandmarX™ Surgical Navigation System in Lateral Skull Base and Temporal Bone Surgery

    PubMed Central

    Staecker, Hinrich; O'Malley, Bert W.; Eisenberg, Howard; Yoder, B. Emmerich

    2001-01-01

    Despite the widespread availability of surgical navigation devices, their use in lateral skull base and temporal bone surgery has been limited. Problems with current systems include difficulty of use and inadequate accuracy. We present a series of cases using the LandmarX™ surgical navigation system as an adjunct for lateral skull base and temporal bone procedures. This infrared emitting diodes (IRED)-driven system has a post that carries the IREDs and bypasses the need to place the patient in a Mayfield head holder. This configuration allows greater mobility of the surgical field. Registration of the patient can include a combination of fiducial and anatomic landmarks that significantly increase accuracy compared to fiducial calibration alone. We introduced the use of the lateral process of the malleus as a landmark, thereby increasing accuracy within the temporal bone to a range of 0.9 to 1.5 mm. We used the system on encephaloceles, glomus tumors, meningiomas, and schwannomas, and revision surgery for chronic otitis media. It decreased operating time, allowed more effective use of “keyhole” approaches, and increased safety. As the availability and flexibility of these systems increase, their use should become the standard of care in revision temporal bone and lateral skull base procedures. ImagesFigure 1Figure 2Figure 3Figure 4 PMID:17167627

  17. Lidar determination of mixing layer height with high resolution

    NASA Astrophysics Data System (ADS)

    Martucci, Giovanni; Matthey, Renaud; Mitev, Valentin; Richner, Hans

    2005-10-01

    Ecological monitoring and analysis of the planetary boundary layer (PBL) dynamics require determination of the mixing layer height (MLH) on a continuous basis. In a number of cases it is necessary to determine the MLH with sufficiently high resolution - both altitude and temporal. The backscatter lidar provides a convenient tool for such determination, using the aerosol as tracer and determining its vertical profile and its time-evolution, with the capability for continuous measurements. Although methods already exist, based on the altitude derivative of the backscatter lidar signal (altitude Gradient method) and its time-variance (Variance method), the application of these methods with high resolution is limited by the background noise presence. We report here a further development of backscatter lidar gradient and variance methods for MLH determination, allowing higher resolutions. In it, the MLH determination from the gradient and the variance of the lidar signal is supported by a convenient filter technique. Time scale of increased temporal resolution allows the investigation of the fine atmospheric dynamic structures like convective motion. A number of examples in MLH retrieval are presented. The examples are based on backscatter lidar measurements performed in the PBL above Neuchatel, Switzerland (47.00°N, 6.95°S, 485m asl). The examples show the applicability and the usefulness of the reported technique in measurements of the daily cycle of the MLH dynamics.

  18. Delayed loss of hearing after hearing preservation cochlear implantation: Human temporal bone pathology and implications for etiology.

    PubMed

    Quesnel, Alicia M; Nakajima, Hideko Heidi; Rosowski, John J; Hansen, Marlan R; Gantz, Bruce J; Nadol, Joseph B

    2016-03-01

    After initially successful preservation of residual hearing with cochlear implantation, some patients experience subsequent delayed hearing loss. The etiology of such delayed hearing loss is unknown. Human temporal bone pathology is critically important in investigating the etiology, and directing future efforts to maximize long term hearing preservation in cochlear implant patients. Here we present the temporal bone pathology from a patient implanted during life with an Iowa/Nucleus Hybrid S8 implant, with initially preserved residual hearing and subsequent hearing loss. Both temporal bones were removed for histologic processing and evaluated. Complete clinical and audiologic records were available. He had bilateral symmetric high frequency severe to profound hearing loss prior to implantation. Since he was implanted unilaterally, the unimplanted ear was presumed to be representative of the pre-implantation pathology related to his hearing loss. The implanted and contralateral unimplanted temporal bones both showed complete degeneration of inner hair cells and outer hair cells in the basal half of the cochleae, and only mild patchy loss of inner hair cells and outer hair cells in the apical half. The total spiral ganglion neuron counts were similar in both ears: 15,138 (56% of normal for age) in the unimplanted right ear and 13,722 (51% of normal for age) in the implanted left ear. In the basal turn of the implanted left cochlea, loose fibrous tissue and new bone formation filled the scala tympani, and part of the scala vestibuli. Delayed loss of initially preserved hearing after cochlear implantation was not explained by additional post-implantation degeneration of hair cells or spiral ganglion neurons in this patient. Decreased compliance at the round window and increased damping in the scala tympani due to intracochlear fibrosis and new bone formation might explain part of the post-implantation hearing loss. Reduction of the inflammatory and immune response to

  19. [The potential of cone beam computed tomography of the temporal bones in the patients presenting with otosclerosis].

    PubMed

    Karpishchenko, S A; Zubareva, A A; Filimonov, V N; Shavgulidze, M A; Azovtseva, E A

    The objective of the present study was to analyze the potential of cone beam computed tomography of the temporal bones in the patients presenting with otosclerosis for the detection of surgically significant specific structural features of the labyrinth wall of the tympanic cavity. More than 400 tomograms of the temporal bones were obtained with the use of a cone beam tomographwere available for the investigation during the period from 2012 till 2016. The study was carried out in several steps, viz. the search for the optimal (for the given instrument) position of the patient, the experimental stage, the retrospective analysis of the tomograms and the comparison of the temporal bones of different types (pneumatic, mixed, and sclerotic) in individual patients, the comparison of the results of cone beam computed tomography (CBCT) with the intraoperative observations, and the modification of the algorithm for the analysis of temporal bone cone beam tomograms. The study included a total of 16 patients (15 women at the age from 32 to 56 years and one managed 58 years) presenting with the clinical diagnosis of otosclerosis. The results of the study were used to elaborate the algorithm for the analysis of cone beam tomograms of the temporal bones to be performed inthe stage by stage manner including the qualitative analysis of tomograms, evaluation of their quantitative parameters and additional characteristics to be taken into consideration when planning the surgical interventions on the labyrinth wall and the tympanic cavity as a preparation for the stapedoplastic treatment. The results of CBCT obtained in the present study were compared with the surgical observations. The diagnostic sensitivity and specificity of the method were estimated to be 100% and 83% respectively. It is concluded that cone beam computed tomography can be employed as a component of the diagnostic algorithm prior to the planning of surgical interventions onthe medial wall of the tympanic cavity

  20. High Resolution Convective Heat Transfer Measurements

    DTIC Science & Technology

    2001-05-30

    ONR Thermal Materials Workshop 2001 1 HIGH RESOLUTION CONVECTIVE HEAT TRANSFER MEASUREMENTS Peter Ireland and Terry Jones R-R UTC in Heat Transfer...temperatures. • Fluid dynamics correct through use of Reynolds number, Mach number and Prandtl number. Mach)Pr,(Re,fNu Dimensionless heat transfer...depends on local h su rf ac e te m p T s gas temperature Tg timestart of test hTc Calibration Test data ONR Thermal Materials Workshop 2001 10 Heat

  1. Use of High Resolution Simulations Training Development

    DTIC Science & Technology

    1988-09-01

    observed data or subject matter expert ( SME ) data for development of training programs. Simulation derived data is neither observable nor viewed as...training developer has habitually relied on SMEs and questionaire data gathering techniques. The nature of current high resolution simulations allow for the...system. These task lists describe the individual and collective tasks to be performed by the operators of the new sem. Additionally, the SMEs on the new

  2. High resolution schemes for hyperbolic conservation laws

    NASA Technical Reports Server (NTRS)

    Harten, A.

    1983-01-01

    A class of new explicit second order accurate finite difference schemes for the computation of weak solutions of hyperbolic conservation laws is presented. These highly nonlinear schemes are obtained by applying a nonoscillatory first order accurate scheme to an appropriately modified flux function. The so-derived second order accurate schemes achieve high resolution while preserving the robustness of the original nonoscillatory first order accurate scheme. Numerical experiments are presented to demonstrate the performance of these new schemes.

  3. A high-resolution anatomical rat atlas

    PubMed Central

    Bai, Xueling; Yu, Li; Liu, Qian; Zhang, Jie; Li, Anan; Han, Dao; Luo, Qingming; Gong, Hui

    2006-01-01

    This paper reports the availability of a high-resolution atlas of the adult rat. The atlas is composed of 9475 cryosectional images captured in 4600 × 2580 × 24-bit TIFF format, constructed using serial cryosection-milling techniques. Cryosection images were segmented, labelled and reconstructed into three-dimensional (3D) computerized models. These images, 3D models, technical details, relevant software and further information are available at our website, http://vchibp.vicp.net/vch/mice/. PMID:17062027

  4. Stellar Tools for High Resolution Population Synthesis

    NASA Astrophysics Data System (ADS)

    Chávez, M.; Bertone, E.; Rodríguez-Merino, L.; Buzzoni, A.

    2005-12-01

    We present preliminary results of the application of a new stellar library of high-resolution synthetic spectra (based upon ATLAS9 and SYNTHE codes developed by R. L. Kurucz) in the calculation of the ultraviolet-optical spectral energy distribution of simple stellar populations (SSPs). For this purpose, the library has been coupled with Buzzoni's population synthesis code. Part of this paper is also devoted to illustrate quantitatively the extent to which synthetic stellar libraries represent real stars.

  5. High-Resolution X-Ray Telescopes

    NASA Technical Reports Server (NTRS)

    ODell, Stephen L.; Brissenden, Roger J.; Davis, William; Elsner, Ronald F.; Elvis, Martin; Freeman, Mark; Gaetz, Terry; Gorenstein, Paul; Gubarev, Mikhail V.

    2010-01-01

    Fundamental needs for future x-ray telescopes: a) Sharp images => excellent angular resolution. b) High throughput => large aperture areas. Generation-X optics technical challenges: a) High resolution => precision mirrors & alignment. b) Large apertures => lots of lightweight mirrors. Innovation needed for technical readiness: a) 4 top-level error terms contribute to image size. b) There are approaches to controlling those errors. Innovation needed for manufacturing readiness. Programmatic issues are comparably challenging.

  6. A High Resolution Ammunition Resupply Model.

    DTIC Science & Technology

    1982-03-01

    Redstone Arsenal, Alabama. HELAPS II is a stochastic, event sequenced simulation that is run on a CDC 6000 series machine with GASP IV simulation language ...high resolution, event sequenced, stochastic model of ground combat. The language used was SINSCRIPT 11.5. Since much of what was developed is still...simulation language . These critical descriptors and the information they convey are as follows: (a) Arcs: length of road segment; type of road

  7. Analysis of intraindividual and intraspecific variation in semicircular canal dimensions using high-resolution x-ray computed tomography.

    PubMed

    Welker, Kelli L; Orkin, Joseph D; Ryan, Timothy M

    2009-10-01

    The semicircular canal system tracks head rotation and provides sensory input for the reflexive stabilization of gaze and posture. The purpose of this study was to investigate the intraspecific and intraindividual variation in the size of the three semicircular canals. The right and left temporal bones were extracted from 31 individuals of the short-tailed shrew (Blarina brevicauda) and scanned on a high-resolution x-ray computed tomography system. The radius of curvature was calculated for each of the three semicircular canals for each side. Paired t-tests and independent sample t-tests indicated no significant differences in canal size between the right and left canals of the same individuals or between those of males and females of the same species. Pearson product moment correlation analyses demonstrated that there was no significant correlation between canal size and body mass in this sample.

  8. Analysis of intraindividual and intraspecific variation in semicircular canal dimensions using high-resolution x-ray computed tomography

    PubMed Central

    Welker, Kelli L; Orkin, Joseph D; Ryan, Timothy M

    2009-01-01

    The semicircular canal system tracks head rotation and provides sensory input for the reflexive stabilization of gaze and posture. The purpose of this study was to investigate the intraspecific and intraindividual variation in the size of the three semicircular canals. The right and left temporal bones were extracted from 31 individuals of the short-tailed shrew (Blarina brevicauda) and scanned on a high-resolution x-ray computed tomography system. The radius of curvature was calculated for each of the three semicircular canals for each side. Paired t-tests and independent sample t-tests indicated no significant differences in canal size between the right and left canals of the same individuals or between those of males and females of the same species. Pearson product moment correlation analyses demonstrated that there was no significant correlation between canal size and body mass in this sample. PMID:19619167

  9. High-Resolution Traction Force Microscopy

    PubMed Central

    Plotnikov, Sergey V.; Sabass, Benedikt; Schwarz, Ulrich S.; Waterman, Clare M.

    2015-01-01

    Cellular forces generated by the actomyosin cytoskeleton and transmitted to the extracellular matrix (ECM) through discrete, integrin-based protein assemblies, that is, focal adhesions, are critical to developmental morphogenesis and tissue homeostasis, as well as disease progression in cancer. However, quantitative mapping of these forces has been difficult since there has been no experimental technique to visualize nanonewton forces at submicrometer spatial resolution. Here, we provide detailed protocols for measuring cellular forces exerted on two-dimensional elastic substrates with a high-resolution traction force microscopy (TFM) method. We describe fabrication of polyacrylamide substrates labeled with multiple colors of fiducial markers, functionalization of the substrates with ECM proteins, setting up the experiment, and imaging procedures. In addition, we provide the theoretical background of traction reconstruction and experimental considerations important to design a high-resolution TFM experiment. We describe the implementation of a new algorithm for processing of images of fiducial markers that are taken below the surface of the substrate, which significantly improves data quality. We demonstrate the application of the algorithm and explain how to choose a regularization parameter for suppression of the measurement error. A brief discussion of different ways to visualize and analyze the results serves to illustrate possible uses of high-resolution TFM in biomedical research. PMID:24974038

  10. High-resolution traction force microscopy.

    PubMed

    Plotnikov, Sergey V; Sabass, Benedikt; Schwarz, Ulrich S; Waterman, Clare M

    2014-01-01

    Cellular forces generated by the actomyosin cytoskeleton and transmitted to the extracellular matrix (ECM) through discrete, integrin-based protein assemblies, that is, focal adhesions, are critical to developmental morphogenesis and tissue homeostasis, as well as disease progression in cancer. However, quantitative mapping of these forces has been difficult since there has been no experimental technique to visualize nanonewton forces at submicrometer spatial resolution. Here, we provide detailed protocols for measuring cellular forces exerted on two-dimensional elastic substrates with a high-resolution traction force microscopy (TFM) method. We describe fabrication of polyacrylamide substrates labeled with multiple colors of fiducial markers, functionalization of the substrates with ECM proteins, setting up the experiment, and imaging procedures. In addition, we provide the theoretical background of traction reconstruction and experimental considerations important to design a high-resolution TFM experiment. We describe the implementation of a new algorithm for processing of images of fiducial markers that are taken below the surface of the substrate, which significantly improves data quality. We demonstrate the application of the algorithm and explain how to choose a regularization parameter for suppression of the measurement error. A brief discussion of different ways to visualize and analyze the results serves to illustrate possible uses of high-resolution TFM in biomedical research. © 2014 Elsevier Inc. All rights reserved.

  11. Microsurgical and Endoscopic Anatomy for Intradural Temporal Bone Drilling and Applications of the Electromagnetic Navigation System: Various Extensions of the Retrosigmoid Approach.

    PubMed

    Matsushima, Ken; Komune, Noritaka; Matsuo, Satoshi; Kohno, Michihiro

    2017-07-01

    The use of the retrosigmoid approach has recently been expanded by several modifications, including the suprameatal, transmeatal, suprajugular, and inframeatal extensions. Intradural temporal bone drilling without damaging vital structures inside or beside the bone, such as the internal carotid artery and jugular bulb, is a key step for these extensions. This study aimed to examine the microsurgical and endoscopic anatomy of the extensions of the retrosigmoid approach and to evaluate the clinical feasibility of an electromagnetic navigation system during intradural temporal bone drilling. Five temporal bones and 8 cadaveric cerebellopontine angles were examined to clarify the anatomy of retrosigmoid intradural temporal bone drilling. Twenty additional cerebellopontine angles were dissected in a clinical setting with an electromagnetic navigation system while measuring the target registration errors at 8 surgical landmarks on and inside the temporal bone. Retrosigmoid intradural temporal bone drilling expanded the surgical exposure to allow access to the petroclival and parasellar regions (suprameatal), internal acoustic meatus (transmeatal), upper jugular foramen (suprajugular), and petrous apex (inframeatal). The electromagnetic navigation continuously guided the drilling without line of sight limitation, and its small devices were easily manipulated in the deep and narrow surgical field in the posterior fossa. Mean target registration error was less than 0.50 mm during these procedures. The combination of endoscopic and microsurgical techniques aids in achieving optimal exposure for retrosigmoid intradural temporal bone drilling. The electromagnetic navigation system had clear advantages with acceptable accuracy including the usability of small devices without line of sight limitation. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Temporal variation and lack of host specificity among bacterial endosymbionts of Osedax bone worms (Polychaeta: Siboglinidae).

    PubMed

    Salathé, Rahel M; Vrijenhoek, Robert C

    2012-09-25

    Osedax worms use a proliferative root system to extract nutrients from the bones of sunken vertebrate carcasses. The roots contain bacterial endosymbionts that contribute to the nutrition of these mouthless and gutless worms. The worms acquire these essential endosymbionts locally from the environment in which their larvae settle. Here we report on the temporal dynamics of endosymbiont diversity hosted by nine Osedax species sampled during a three-year investigation of an experimental whale fall at 1820-m depth in the Monterey Bay, California. The host species were identified by their unique mitochondrial COI haplotypes. The endosymbionts were identified by ribotyping with PCR primers specifically designed to target Oceanospirillales. Thirty-two endosymbiont ribotypes associated with these worms clustered into two distinct bacterial ribospecies that together comprise a monophyletic group, mostly restricted to deep waters (>1000 m). Statistical analyses confirmed significant changes in the relative abundances of host species and the two dominant endosymbiont ribospecies during the three-year sampling period. Bone type (whale vs. cow) also had a significant effect on host species, but not on the two dominant symbiont ribospecies. No statistically significant association existed between the host species and endosymbiont ribospecies. Standard PCR and direct sequencing proved to be an efficient method for ribotyping the numerically dominant endosymbiont strains infecting a large sample of host individuals; however, this method did not adequately represent the frequency of mixed infections, which appears to be the rule rather than an exception for Osedax individuals. Through cloning and the use of experimental dilution series, we determined that minority ribotypes constituting less than 30% of a mixture would not likely be detected, leading to underestimates of the frequency of multiple infections in host individuals.

  13. Temporal variation and lack of host specificity among bacterial endosymbionts of Osedax bone worms (Polychaeta: Siboglinidae)

    PubMed Central

    2012-01-01

    Background Osedax worms use a proliferative root system to extract nutrients from the bones of sunken vertebrate carcasses. The roots contain bacterial endosymbionts that contribute to the nutrition of these mouthless and gutless worms. The worms acquire these essential endosymbionts locally from the environment in which their larvae settle. Here we report on the temporal dynamics of endosymbiont diversity hosted by nine Osedax species sampled during a three-year investigation of an experimental whale fall at 1820-m depth in the Monterey Bay, California. The host species were identified by their unique mitochondrial COI haplotypes. The endosymbionts were identified by ribotyping with PCR primers specifically designed to target Oceanospirillales. Results Thirty-two endosymbiont ribotypes associated with these worms clustered into two distinct bacterial ribospecies that together comprise a monophyletic group, mostly restricted to deep waters (>1000 m). Statistical analyses confirmed significant changes in the relative abundances of host species and the two dominant endosymbiont ribospecies during the three-year sampling period. Bone type (whale vs. cow) also had a significant effect on host species, but not on the two dominant symbiont ribospecies. No statistically significant association existed between the host species and endosymbiont ribospecies. Conclusions Standard PCR and direct sequencing proved to be an efficient method for ribotyping the numerically dominant endosymbiont strains infecting a large sample of host individuals; however, this method did not adequately represent the frequency of mixed infections, which appears to be the rule rather than an exception for Osedax individuals. Through cloning and the use of experimental dilution series, we determined that minority ribotypes constituting less than 30% of a mixture would not likely be detected, leading to underestimates of the frequency of multiple infections in host individuals. PMID:23006795

  14. High temporal and spatial resolution studies of bone cells using real-time confocal reflection microscopy.

    PubMed

    Boyde, A; Vesely, P; Gray, C; Jones, S J

    1994-01-01

    Chick and rat bone-derived cells were mounted in sealed coverslip-covered chambers; individual osteoclasts (but also osteoblasts) were selected and studied at 37 degrees C using three different types of high-speed scanning confocal microscopes: (1) A Noran Tandem Scanning Microscope (TSM) was used with a low light level, cooled CCD camera for image transfer to a Noran TN8502 frame store-based image analysing computer to make time lapse movie sequences using 0.1 s exposure periods, thus losing some of the advantage of the high frame rate of the TSM. Rapid focus adjustment using computer controlled piezo drivers permitted two or more focus planes to be imaged sequentially: thus (with additional light-source shuttering) the reflection confocal image could be alternated with the phase contrast image at a different focus. Individual cells were followed for up to 5 days, suggesting no significant irradiation problem. (2) Exceptional temporal and spatial resolution is available in video rate laser confocal scanning microscopes (VRCSLMs). We used the Noran Odyssey unitary beam VRCSLM with an argon ion laser at 488 nm and acousto-optic deflection (AOD) on the line axis: this instrument is truly and adjustably confocal in the reflection mode. (3) We also used the Lasertec 1LM11 line scan instrument, with an He-Ne laser at 633 nm, and AOD for the frame scan. We discuss the technical problems and merits of the different approaches. The VRCSLMs documented rapid, real-time oscillatory motion: all the methods used show rapid net movement of organelles within bone cells. The interference reflection mode gives particularly strong contrasts in confocal instruments. Phase contrast and other interference methods used in the microscopy of living cells can be used simultaneously in the TSM.

  15. Proceedings of the workshop on high resolution computed microtomography (CMT)

    SciTech Connect

    1997-02-01

    The purpose of the workshop was to determine the status of the field, to define instrumental and computational requirements, and to establish minimum specifications required by possible users. The most important message sent by implementers was the remainder that CMT is a tool. It solves a wide spectrum of scientific problems and is complementary to other microscopy techniques, with certain important advantages that the other methods do not have. High-resolution CMT can be used non-invasively and non-destructively to study a variety of hierarchical three-dimensional microstructures, which in turn control body function. X-ray computed microtomography can also be used at the frontiers of physics, in the study of granular systems, for example. With high-resolution CMT, for example, three-dimensional pore geometries and topologies of soils and rocks can be obtained readily and implemented directly in transport models. In turn, these geometries can be used to calculate fundamental physical properties, such as permeability and electrical conductivity, from first principles. Clearly, use of the high-resolution CMT technique will contribute tremendously to the advancement of current R and D technologies in the production, transport, storage, and utilization of oil and natural gas. It can also be applied to problems related to environmental pollution, particularly to spilling and seepage of hazardous chemicals into the Earth's subsurface. Applications to energy and environmental problems will be far-ranging and may soon extend to disciplines such as materials science--where the method can be used in the manufacture of porous ceramics, filament-resin composites, and microelectronics components--and to biomedicine, where it could be used to design biocompatible materials such as artificial bones, contact lenses, or medication-releasing implants. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  16. Three-dimensional virtual model of the human temporal bone: a stand-alone, downloadable teaching tool.

    PubMed

    Wang, Haobing; Northrop, Clarinda; Burgess, Barbara; Liberman, M Charles; Merchant, Saumil N

    2006-06-01

    To develop a three-dimensional virtual model of a human temporal bone based on serial histologic sections. The three-dimensional anatomy of the human temporal bone is complex, and learning it is a challenge for students in basic science and in clinical medicine. Every fifth histologic section from a normal 14-year-old male was digitized and imported into a general purpose three-dimensional rendering and analysis software package called Amira (version 3.1). The sections were aligned, and anatomic structures of interest were segmented. The three-dimensional model is a surface rendering of these structures of interest, which currently includes the bone and air spaces of the temporal bone; the perilymph and endolymph spaces; the sensory epithelia of the cochlear and vestibular labyrinths; the ossicles and tympanic membrane; the middle ear muscles; the carotid artery; and the cochlear, vestibular, and facial nerves. For each structure, the surface transparency can be individually controlled, thereby revealing the three-dimensional relations between surface landmarks and underlying structures. The three-dimensional surface model can also be "sliced open" at any section and the appropriate raw histologic image superimposed on the cleavage plane. The image stack can also be resectioned in any arbitrary plane. This model is a powerful teaching tool for learning the complex anatomy of the human temporal bone and for relating the two-dimensional morphology seen in a histologic section to the three-dimensional anatomy. The model can be downloaded from the Eaton-Peabody Laboratory web site, packaged within a cross-platform freeware three-dimensional viewer, which allows full rotation and transparency control.

  17. Universal multifractal analysis of high-resolution snowfall data

    NASA Astrophysics Data System (ADS)

    Raupach, Timothy; Gires, Auguste; Tchiguirinskaia, Ioulia; Schertzer, Daniel; Berne, Alexis

    2016-04-01

    Universal multifractal analysis offers useful insights into the scaling properties of precipitation data. While much work has been done on the scaling properties of rainfall fields, less is known about the scaling properties of solid precipitation such as snowfall, especially at high resolution. We present results of a universal multifractal (UM) analysis of high-resolution solid precipitation data. The data were recorded using a 2D-video-disdrometer (2DVD) situated in the Swiss Alps. Analysis was performed on a one-hour period of snowfall, during which time the mean wind speed was zero, temperatures were low, and no hail was detected. The 2DVD recorded information on individual particles, from which we calculated snow mass. Three "cuts" of the spatio-temporal snowfall process were analysed using the UM framework. First, high-resolution timeseries of precipitation intensity at 100 ms temporal resolution were analysed. These results show two scaling regimes with a transition area between them. Second, we analysed reconstructed vertical columns of particle concentration and snow mass, assuming no horizontal wind and constant vertical velocity (equal to the one recorded on the ground). Strong scaling was observed in the particle concentration fields, with the influence of large (and therefore rare) snowflakes degrading the quality of the scaling observed for higher moments of the particle distribution. There was a clear difference between the measured fields and fields in which the vertical distribution of particles was made homogeneous, indicating that the measured snowfall fields contained non-homogeneous fields. Scaling behaviour was observed down to vertical scales of about 0.5 m, which is similar to published results using rain data. Finally, we used the UM framework to investigate the scaling properties of 2D maps of snow accumulation over a subset of the instrument collection area of 5.12 x 5.12 cm^2. As expected from the vertical column analysis, given that

  18. Temporomandibular joints: high-resolution computed tomographic evaluation

    SciTech Connect

    Thompson, J.R.; Christiansen, E.; Hasso, A.N.; Hinshaw, D.B. Jr.

    1984-01-01

    High-resolution computed tomography of the temporomandibular joint (TMJ) was performed in 43 patients. Exquisite detail of the face, skull base, and TMJs was obtained with CT using soft tissue and bone algorithms, narrow collimation, and multiplanar images. In 10 patients clinically suspected of joint derangement, CT results were in close agreement with surgical findings and arthrography in 13/15 joints. CT showed indirect signs of disc dislocation, and the dislocated disc itself in 81% of affected joints. In two patients, arthrography with CT proved to be more helpful than conventional arthrography alone. CT without intra-articular contrast material provided information not appreciated on conventional radiogaphs in 28 patients (65%) and was particularly helpful in evaluating patients with disc pathosis and trauma. Early experience with CT of the TMJ shows that it is an excellent method of evaluation at acceptable radiation exposure levels that adds essential information not seen on standard radiographs.

  19. Effects of anatomical variation on trainee performance in a virtual reality temporal bone surgery simulator.

    PubMed

    Piromchai, P; Ioannou, I; Wijewickrema, S; Kasemsiri, P; Lodge, J; Kennedy, G; O'Leary, S

    2017-01-01

    To investigate the importance of anatomical variation in acquiring skills in virtual reality cochlear implant surgery. Eleven otolaryngology residents participated in this study. They were randomly allocated to practice cochlear implant surgery on the same specimen or on different specimens for four weeks. They were then tested on two new specimens, one standard and one challenging. Videos of their performance were de-identified and reviewed independently, by two blinded consultant otolaryngologists, using a validated assessment scale. The scores were compared between groups. On the standard specimen, the round window preparation score was 2.7 ± 0.4 for the experimental group and 1.7 ± 0.6 for the control group (p = 0.01). On the challenging specimen, instrument handling and facial nerve preservation scores of the experimental group were 3.0 ± 0.4 and 3.5 ± 0.7 respectively, while the control group received scores of 2.1 ± 0.8 and 2.4 ± 0.9 respectively (p < 0.05). Training on temporal bones with differing anatomies is beneficial in the development of expertise.

  20. A 3-D analysis of the protympanum in human temporal bones with chronic ear disease.

    PubMed

    Pauna, Henrique F; Monsanto, Rafael C; Schachern, Patricia; Paparella, Michael M; Cureoglu, Sebahattin

    2017-03-01

    Eustachian tube dysfunction is believed to be an important factor to cholesteatoma development and recurrence of disease after surgical treatment. Although many studies have described prognostic factors, evaluation methods, or surgical techniques for Eustachian tube dysfunction, they relied on the soft tissues of its structure; little is known about its bony structure-the protympanum-which connects the Eustachian tube to the tympanic cavity, and can also be affected by several inflammatory conditions, both from the middle ear or from the nasopharynx. We studied temporal bones from patients with cholesteatoma, chronic otitis media (with and without retraction pockets), purulent otitis media, and non-diseased ears, looking for differences between the volume of the protympanum, the diameter of the Eustachian tube isthmus, and the distance between the anterior tympanic annulus and the promontory. Light microscopy and 3-D reconstruction software were used for the measurements. We observed a decrease of volume in the lumen of the four middle ear diseased ears compared to the control group. We observed a significant decrease in the volume of the protympanic space in the cholesteatoma group compared to the chronic otitis media group. We also observed a decrease in the bony space (protympanum space) in cholesteatoma, chronic otitis media with retraction pockets, and purulent otitis media compared to the control group. We found a correlation in middle ear diseases and a decrease in the middle ear space. Our findings may suggest that a smaller bony volume in the protympanic area may trigger middle ear dysventilation problems.

  1. Completely-in-the-canal magnet-drive hearing device: a temporal bone study.

    PubMed

    Mahboubi, Hossein; Malley, Melinda J D; Paulick, Peyton; Merlo, Mark W; Bachman, Mark; Djalilian, Hamid R

    2013-03-01

    The magnet-drive hearing device (MHD) is a small completely-in-the-canal hearing aid prototype that drives the tympanic membrane (TM) through a magnetic interface. A cadaveric temporal bone was prepared. The MHD was coupled to a nickel-epoxy pellet glued to the umbo. Frequency sweeps between 0.3 and 10 kHz were performed, and the MHD was d