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Sample records for microcomputed tomography comparison

  1. Comparison of micro-computed tomography and laser scanning for reverse engineering orthopaedic component geometries.

    PubMed

    Teeter, Matthew G; Brophy, Paul; Naudie, Douglas D R; Holdsworth, David W

    2012-03-01

    A significant amount of research has been undertaken to evaluate the function of implanted joint replacement components. Many of these studies require the acquisition of an accurate three-dimensional geometric model of the various implant components, using methods such as micro-computed tomography or laser scanning. The purpose of this study was to compare micro-computed tomography and laser scanning for obtaining component geometries. Five never-implanted polyethylene tibial inserts of one type were scanned with both micro-computed tomography and laser scanning to determine the repeatability of each method and measured for any deviations between the geometries acquired from the different scans. Overall, good agreement was found between the micro-computed tomography and laser scans, to within 71 microm on average. Micro-computed tomography was found to have superior repeatability to laser scanning (mean of 1 microm for micro-computed tomography versus 19 microm for laser scans). Micro-computed tomography may be preferred for visualizing small surface features, whereas laser scanning may be preferred for acquiring the geometry of metal objects to avoid computed tomography artifacts. In conclusion, the choice of micro-computed tomography versus laser scanning for acquiring orthopaedic component geometries will likely involve considerations of user preference, the specific application the scan will be used for, and the availability of each system.

  2. Assessing apical transportation in curved canals: comparison between cross-sections and micro-computed tomography.

    PubMed

    Freire, Laila Gonzales; Gavini, Giulio; Cunha, Rodrigo Sanches; Santos, Marcelo dos

    2012-01-01

    The aim of this study was to compare two methods of assessing apical transportation in curved canals after rotary instrumentation, namely, cross-sections and micro-computed tomography (µCT). Thirty mandibular molars were divided into two groups and prepared according to the requirements of each method. In G1 (cross-sections), teeth were embedded in resin blocks and sectioned at 2.0, 3.5, and 5.0 mm from the anatomic apex. Pre- and postoperative sections were photographed and analyzed. In G2 (µCT), teeth were embedded in a rubber-base impression material and scanned before and after instrumentation. Mesiobuccal canals were instrumented with the Twisted File (TF) system (SybronEndo, Orange, USA), and mesiolingual canals, with the EndoSequence (ES) system (Brasseler, Savannah, USA). Images were reconstructed, and sections corresponding to distances 2.0, 3.5, and 5.0 mm from the anatomic apex were selected for comparison. Data were analyzed using Mann-Whitney's test at a 5% significance level. The TF and ES instruments produced little deviation from the root canal center, with no statistical difference between them (P > 0.05). The canal transportation results were significantly lower (0.056 mm) in G2 than in G1 (0.089 mm) (p = 0.0012). The µCT method was superior to the cross-section method, especially in view of its ability to preserve specimens and provide results that are more closely related to clinical situations.

  3. Comparison of optical coherence tomography, microcomputed tomography, and histology at a three-dimensionally imaged trabecular bone sample

    NASA Astrophysics Data System (ADS)

    Kasseck, Christoph; Kratz, Marita; Torcasio, Antonia; Gerhardt, Nils C.; van Lenthe, G. Harry; Gambichler, Thilo; Hoffmann, Klaus; Jones, David B.; Hofmann, Martin R.

    2010-07-01

    We investigate optical coherence tomography (OCT) as a method for imaging bone. The OCT images are compared directly to those of the standard methods of bone histology and microcomputed tomography (μCT) on a single, fixed human femoral trabecular bone sample. An advantage of OCT over bone histology is its noninvasive nature. OCT also images the lamellar structure of trabeculae at slightly higher contrast than normal bone histology. While μCT visualizes the trabecular framework of the whole sample, OCT can image additionally cells with a penetration depth limited approximately to 1 mm. The most significant advantage of OCT, however, is the absence of toxic effects (no ionizing radiation), i.e., continuous images may be made and individual cell tracking may be performed. The penetration depth of OCT, however, limits its use to small animal models and small bone organ cultures.

  4. Assessment of BoneTtissue Mineralization by Conventional X-ray Microcomputed tomography: Comparison with Synchrotron Radiation Microcomputed Tomography and Ash Measurements

    SciTech Connect

    Kazakia,G.; Burghardt, A.; Cheung, S.; Majumdar, S.

    2008-01-01

    Assessment of bone tissue mineral density (TMD) may provide information critical to the understanding of mineralization processes and bone biomechanics. High-resolution three-dimensional assessment of TMD has recently been demonstrated using synchrotron radiation microcomputed tomography (SR{mu}CT); however, this imaging modality is relatively inaccessible due to the scarcity of SR facilities. Conventional desktop {mu}CT systems are widely available and have been used extensively to assess bone microarchitecture. However, the polychromatic source and cone-shaped beam geometry complicate assessment of TMD by conventional {mu}CT. The goal of this study was to evaluate {mu}CT-based measurement of degree and distribution of tissue mineralization in a quantitative, spatially resolved manner. Specifically, {mu}CT measures of bone mineral content (BMC) and TMD were compared to those obtained by SR{mu}CT and gravimetric methods. Cylinders of trabecular bone were machined from human femoral heads (n=5), vertebrae (n=5), and proximal tibiae (n=4). Cylinders were imaged in saline on a polychromatic {mu}CT system at an isotropic voxel size of 8 {mu}m. Volumes were reconstructed using beam hardening correction algorithms based on hydroxyapatite (HA)-resin wedge phantoms of 200 and 1200 mgHA/cm3. SR{mu}CT imaging was performed at an isotropic voxel size of 7.50 {mu}m at the National Synchrotron Light Source. Attenuation values were converted to HA concentration using a linear regression derived by imaging a calibration phantom. Architecture and mineralization parameters were calculated from the image data. Specimens were processed using gravimetric methods to determine ash mass and density. {mu}CT-based BMC values were not affected by altering the beam hardening correction. Volume-averaged TMD values calculated by the two corrections were significantly different (p=0.008) in high volume fraction specimens only, with the 1200 mgHA/cm3 correction resulting in a 4.7% higher TMD

  5. Digital Tomosynthesis and High Resolution Computed Tomography as Clinical Tools for Vertebral Endplate Topography Measurements: Comparison with Microcomputed Tomography

    PubMed Central

    Oravec, Daniel; Quazi, Abrar; Xiao, Angela; Yang, Ellen; Zauel, Roger; Flynn, Michael J.; Yeni, Yener N.

    2015-01-01

    Endplate morphology is understood to play an important role in the mechanical behavior of vertebral bone as well as degenerative processes in spinal tissues; however, the utility of clinical imaging modalities in assessment of the vertebral endplate has been limited. The objective of this study was to evaluate the ability of two clinical imaging modalities (digital tomosynthesis, DTS; high resolution computed tomography, HRCT) to assess endplate topography by correlating the measurements to a microcomputed tomography (µCT) standard. DTS, HRCT, and µCT images of 117 cadaveric thoracolumbar vertebrae (T10-L1; 23 male, 19 female; ages 36–100 years) were segmented, and inferior and superior endplate surface topographical distribution parameters were calculated. Both DTS and HRCT showed statistically significant correlations with µCT approaching a moderate level of correlation at the superior endplate for all measured parameters (R2Adj=0.19–0.57), including averages, variability, and higher order statistical moments. Correlation of average depths at the inferior endplate was comparable to the superior case for both DTS and HRCT (R2Adj=0.14–0.51), while correlations became weak or nonsignificant for higher moments of the topography distribution. DTS was able to capture variations in the endplate topography to a slightly better extent than HRCT, and taken together with the higher speed and lower radiation cost of DTS than HRCT, DTS appears preferable for endplate measurements. PMID:26220145

  6. Nondestructive observation of teeth post core-space using optical coherence tomography: comparison with microcomputed tomography and live images

    NASA Astrophysics Data System (ADS)

    Minamino, Takuya; Mine, Atsushi; Matsumoto, Mariko; Sugawa, Yoshihiko; Kabetani, Tomoshige; Higashi, Mami; Kawaguchi, Asuka; Ohmi, Masato; Awazu, Kunio; Yatani, Hirofumi

    2015-10-01

    No previous reports have observed inside the root canal using both optical coherence tomography (OCT) and x-ray microcomputed tomography (μCT) for the same sample. The purpose of this study was to clarify both OCT and μCT image properties from observations of the same root canal after resin core build-up treatment. As OCT allows real-time observation of samples, gap formation may be able to be shown in real time. A dual-cure, one-step, self-etch adhesive system bonding agent, and dual-cure resin composite core material were used in root canals in accordance with instructions from the manufacturer. The resulting OCT images were superior for identifying gap formation at the interface, while μCT images were better to grasp the tooth form. Continuous tomographic images from real-time OCT observation allowed successful construction of a video of the resin core build-up procedure. After 10 to 12 s of light curing, a gap with a clear new signal occurred at the root-core material interface, proceeding from the coronal side (6 mm from the cemento-enamel junction) to the apical side of the root.

  7. Digital tomosynthesis and high resolution computed tomography as clinical tools for vertebral endplate topography measurements: Comparison with microcomputed tomography.

    PubMed

    Oravec, Daniel; Quazi, Abrar; Xiao, Angela; Yang, Ellen; Zauel, Roger; Flynn, Michael J; Yeni, Yener N

    2015-12-01

    Endplate morphology is understood to play an important role in the mechanical behavior of vertebral bone as well as degenerative processes in spinal tissues; however, the utility of clinical imaging modalities in assessment of the vertebral endplate has been limited. The objective of this study was to evaluate the ability of two clinical imaging modalities (digital tomosynthesis, DTS; high resolution computed tomography, HRCT) to assess endplate topography by correlating the measurements to a microcomputed tomography (μCT) standard. DTS, HRCT, and μCT images of 117 cadaveric thoracolumbar vertebrae (T10-L1; 23 male, 19 female; ages 36-100 years) were segmented, and inferior and superior endplate surface topographical distribution parameters were calculated. Both DTS and HRCT showed statistically significant correlations with μCT approaching a moderate level of correlation at the superior endplate for all measured parameters (R(2)Adj=0.19-0.57), including averages, variability, and higher order statistical moments. Correlation of average depths at the inferior endplate was comparable to the superior case for both DTS and HRCT (R(2)Adj=0.14-0.51), while correlations became weak or nonsignificant for higher moments of the topography distribution. DTS was able to capture variations in the endplate topography to a slightly better extent than HRCT, and taken together with the higher speed and lower radiation cost of DTS than HRCT, DTS appears preferable for endplate measurements.

  8. Nondestructive observation of teeth post core-space using optical coherence tomography: comparison with microcomputed tomography and live images.

    PubMed

    Minamino, Takuya; Mine, Atsushi; Matsumoto, Mariko; Sugawa, Yoshihiko; Kabetani, Tomoshige; Higashi, Mami; Kawaguchi, Asuka; Ohmi, Masato; Awazu, Kunio; Yatani, Hirofumi

    2015-10-01

    No previous reports have observed inside the root canal using both optical coherence tomography (OCT) and x-ray microcomputed tomography (μCT) for the same sample. The purpose of this study was to clarify both OCT and μCT image properties from observations of the same root canal after resin core build-up treatment. As OCT allows real-time observation of samples, gap formation may be able to be shown in real time. A dual-cure, one-step, self-etch adhesive system bonding agent, and dual-cure resin composite core material were used in root canals in accordance with instructions from the manufacturer. The resulting OCT images were superior for identifying gap formation at the interface, while μCT images were better to grasp the tooth form. Continuous tomographic images from real-time OCT observation allowed successful construction of a video of the resin core build-up procedure. After 10 to 12 s of light curing, a gap with a clear new signal occurred at the root-core material interface, proceeding from the coronal side (6 mm from the cemento-enamel junction) to the apical side of the root.

  9. Comparisons of the diagnostic accuracies of optical coherence tomography, micro-computed tomography, and histology in periodontal disease: an ex vivo study

    PubMed Central

    2017-01-01

    Purpose Optical coherence tomography (OCT) is a noninvasive diagnostic technique that may be useful for both qualitative and quantitative analyses of the periodontium. Micro-computed tomography (micro-CT) is another noninvasive imaging technique capable of providing submicron spatial resolution. The purpose of this study was to present periodontal images obtained using ex vivo dental OCT and to compare OCT images with micro-CT images and histologic sections. Methods Images of ex vivo canine periodontal structures were obtained using OCT. Biologic depth measurements made using OCT were compared to measurements made on histologic sections prepared from the same sites. Visual comparisons were made among OCT, micro-CT, and histologic sections to evaluate whether anatomical details were accurately revealed by OCT. Results The periodontal tissue contour, gingival sulcus, and the presence of supragingival and subgingival calculus could be visualized using OCT. OCT was able to depict the surface topography of the dentogingival complex with higher resolution than micro-CT, but the imaging depth was typically limited to 1.2–1.5 mm. Biologic depth measurements made using OCT were a mean of 0.51 mm shallower than the histologic measurements. Conclusions Dental OCT as used in this study was able to generate high-resolution, cross-sectional images of the superficial portions of periodontal structures. Improvements in imaging depth and the development of an intraoral sensor are likely to make OCT a useful technique for periodontal applications. PMID:28261522

  10. X-Ray Micro-Computed Tomography Imaging of the Buzzard Coulee Chondrite

    NASA Astrophysics Data System (ADS)

    Melanson, D.; Samson, C.; Herd, R. K.; Fry, C.; McCausland, P. J. A.; Umoh, J.; Holdsworth, D. W.

    2012-03-01

    This abstract outlines research and some results of X-ray micro-computed tomography imaging of the Buzzard Coulee H4 chondrite. A comparison of bulk density results and an analysis of radio-density profile curves are discussed.

  11. Comparison of two techniques for selection of master gutta-percha cone using micro-computed tomography.

    PubMed

    Silva-Filho, João Manoel; Souza-Gabriel, Aline Evangelista; Leoni, Graziela Bianchi; De-Bem, Samuel Henrique Câmara; Alfredo, Edson; Silva, Ricardo Gariba

    2013-01-01

    This study used micro-computed tomography (micro-CT) to evaluate the fit of the master gutta-percha cone at time of cone fit, gutta-percha volume in the filling material, and the filling material volume in relation to the canal at the apical limit of the working length. Root canals of 20 maxillary central incisors were prepared with rotary instruments and distributed into two groups (n=10). The gutta-percha cone tip was either plasticized (apical thermal impression technique - ATI) or not (conventional technique - CT), and its apical fit was checked. The apical 1 mm of working length was examined with a micro-CT, canals were filled with gutta-percha and sealer, and new micro-CT scans were obtained. In CT, gutta-percha filled 35.83 ± 15.05% of the canal at cone selection and 38.72 ± 11.64% after filling. In ATI, these values were 23.14 ± 7.74% and 26.98 ± 20.40%, respectively. Gutta-percha volume in the filling material, and filling material volume in relation to the canal were, respectively, 61.28 ± 11.64% and 87.76 ± 9.98% for CT, and 73.00 ± 20.41% and 89.96 ± 9.08% for ATI. No significant difference was found between cone selection and after canal filling, for either CT (p=0.593) or ATI (p=0.4975). The techniques did not differ significantly with respect to gutta-percha volume in the filling material (p=0.132) and filling material volume in relation to the canal (p=0.612). An ideal fit of the master gutta-percha cone at working length was not achieved regardless of the cone selection technique, and the material-filled area was similar for both techniques.

  12. Comparison of synchrotron radiation and conventional x-ray microcomputed tomography for assessing trabecular bone microarchitecture of human femoral heads

    SciTech Connect

    Chappard, Christine; Basillais, Armelle; Benhamou, Laurent; Bonassie, Alexandra; Brunet-Imbault, Barbara; Bonnet, Nicolas; Peyrin, Francoise

    2006-09-15

    Microcomputed tomography ({mu}CT) produces three-dimensional (3D) images of trabecular bone. We compared conventional {mu}CT (C{mu}CT) with a polychromatic x-ray cone beam to synchrotron radiation (SR) {mu}CT with a monochromatic parallel beam for assessing trabecular bone microarchitecture of 14 subchondral femoral head specimens from patients with osteoarthritis (n=10) or osteoporosis (n=4). SR{mu}CT images with a voxel size of 10.13 {mu}m were reconstructed from 900 2D radiographic projections (angular step, 0.2 deg. ). C{mu}CT images with a voxel size of 10.77 {mu}m were reconstructed from 205, 413, and 825 projections obtained using angular steps of 0.9 deg., 0.45 deg., and 0.23 deg., respectively. A single threshold was used to binarize the images. We computed bone volume/tissue volume (BV/TV), bone surface/bone volume (BS/BV), trabecular number (Tb.N), trabecular thickness (Tb.Th and Tb.Th*), trabecular spacing (Tb.Sp), degree of anisotropy (DA), and Euler density. With the 0.9 deg. angular step, all C{mu}CT values were significantly different from SR{mu}CT values. With the 0.23 deg. and 0.45 deg. rotation steps, BV/TV, Tb.Th, and BS/BV by C{mu}CT differed significantly from the values by SR{mu}CT. The error due to slice matching (visual site matching {+-}10 slices) was within 1% for most parameters. Compared to SR{mu}CT, BV/TV, Tb.Sp, and Tb.Th by C{mu}CT were underestimated, whereas Tb.N and Tb.Th* were overestimated. A Bland and Altman plot showed no bias for Tb.N or DA. Bias was -0.8{+-}1.0%, +5.0{+-}1.1 {mu}m, -5.9{+-}6.3 {mu}m, and -5.7{+-}29.1 {mu}m for BV/TV, Tb.Th*, Tb.Th, and Tb.Sp, respectively, and the differences did not vary over the range of values. Although systematic differences were noted between SR{mu}CT and C{mu}CT values, correlations between the techniques were high and the differences would probably not change the discrimination between study groups. C{mu}CT provides a reliable 3D assessment of human defatted bone when working at the 0

  13. Comparison of bioimpedance spectroscopy and X-Ray micro-computed tomography for total fat volume measurement in mice.

    PubMed

    Aubertin, Gaelle; Sayeh, Amira; Dillenseger, Jean-Philippe; Ayme-Dietrich, Estelle; Choquet, Philippe; Niederhoffer, Nathalie

    2017-01-01

    Obesity and the metabolic syndrome are two pathologies whose prevalence are in a constant increase. Evaluation of the total fat mass but also of the distribution between visceral and subcutaneous adipose tissue are important factors while assessing the pathophysiology of these two pathologies. Computed tomography (CT) and bioimpedance (BIS) are the translational methods the most frequently used in human beings as well as in rodent models in longitudinal studies on adiposity and obesity. Surprisingly, no direct comparison of micro-CT and BIS was reported yet in mice. Therefore, the present study was carried out to evaluate and compare the accuracy and the uncertainty of measurement of micro-CT and BIS in this species. The proportion of fat mass was measured with BIS, micro-CT and direct post-mortem tissue weight, and correlations between the data were established to evaluate the accuracy of the methods but also the uncertainty of BIS and micro-CT. There were significant correlations between weights of fat tissues on scale and proportion of total fat mass determined by BIS or micro-CT (r = 0.81 and 0.86 respectively) but both methods overestimated the total fat mass, especially in the smallest animals; overestimation of fat mass was amplified with BIS compared to micro-CT. In addition BIS and micro-CT were highly correlated (r = 0.94). Test-test reliability showed a greater variability of the BIS with respect to the micro-CT (coefficient of variation = 17.2 vs 5.6% respectively). Hence, as far as subtle differences between groups or changes within one group are awaited, micro-CT may appear as the most reliable method for determination of fat mass in mice. Micro-CT, unlike BIS, will also allow to qualitatively and quantitatively differentiate between subcutaneous and visceral adipose tissues, which is of major importance in studies on adiposity and its complications.

  14. Micro-computed tomography, scanning electron microscopy and energy X-ray spectroscopy studies of facet joint degeneration: A comparison to clinical imaging.

    PubMed

    Goehre, Felix; Ludtka, Christopher; Hamperl, Melanie; Friedmann, Andrea; Straube, Anja; Mendel, Thomas; Heilmann, Andreas; Meisel, Hans Jörg; Schwan, Stefan

    2017-09-01

    Segmental degeneration in the human lumbar spine affects both the intervertebral discs and facet joints. Facet joint degeneration not only affects the cartilage surface, but also alters the cellular properties of the cartilage tissue and the structure of the subchondral bone. The primary focus of this study is the investigation of these microstructural changes that are caused by facet joint degeneration. Microstructural analyses of degenerated facet joint samples, obtained from patients following operative lumbar interbody fusion, have not previously been extensively investigated. This study analyzes human facet joint samples from the inferior articular process using scanning electron microscopy, micro-computed tomography, and energy dispersive X-ray spectroscopy to evaluate parameters of interest in facet joint degeneration such as elemental composition, cartilage layer thickness and cell density, calcification zone thickness, subchondral bone portion, and trabecular bone porosity. These microstructural analyses demonstrate fragmentation, cracking, and destruction of the cartilage layer, a thickened calcification zone, localized calcification areas, and cell cluster formation as pathological manifestations of facet joint degeneration. The detailed description of these microstructural changes is critical for a comprehensive understanding of the pathology of facet joint degeneration, as well as the subsequent development and efficacy analysis of regenerative treatment strategies. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. [Comparison of effectiveness and safety between Twisted File technique and ProTaper Universal rotary full sequence based on micro-computed tomography].

    PubMed

    Chen, Xiao-bo; Chen, Chen; Liang, Yu-hong

    2016-02-18

    To evaluate the efficacy and security of two type of rotary nickel titanium system (Twisted File and ProTaper Universal) for root canal preparation based on micro-computed tomography(micro-CT). Twenty extracted molars (including 62 canals) were divided into two experimental groups and were respectively instrumented using Twisted File rotary nickel titanium system (TF) and ProTaper Universal rotary nickel titanium system (PU) to #25/0.08 following recommended protocol. Time for root canal instrumentation (accumulation of time for every single file) was recorded. The 0-3 mm root surface from apex was observed under an optical stereomicroscope at 25 × magnification. The presence of crack line was noted. The root canals were scanned with micro-CT before and after root canal preparation. Three-dimensional shape images of canals were reconstructed, calculated and evaluated. The amount of canal central transportation of the two groups was calculated and compared. The shorter preparation time [(0.53 ± 0.14) min] was observed in TF group, while the preparation time of PU group was (2.06 ± 0.39) min (P<0.05). In mid-root level, TF group shaping resulted in less canal center transportation than PU group [(0.070 ± 0.056) mm vs. (0.097 ± 0.084) mm, P<0.05]. No instrument separation was observed in both the groups. Cracks were not found in both the groups either based in micro-CT images or observation under an optical stereomicroscope at 25 × magnification. Compared with ProTaper Universal, Twisted File took less time in root canal preparation and exhibited better shaping ability, and less canal transportation.

  16. Comparison of Synchrotron Radiation-based Propagation Phase Contrast Imaging and Conventional Micro-computed Tomography for Assessing Intervertebral Discs and Endplates in a Murine Model.

    PubMed

    Hu, Jianzhong; Ni, Shuangfei; Cao, Yong; Wang, Xiaokai; Liao, Shenghui; Lu, Hongbin

    2017-08-01

    The synchrotron radiation-based micro-computed tomography (SRμCT) and micro-CT (μCT) were applied to comparatively assess the intervertebral disc (IVD) and endplate (EP). To explore a new approach to evaluate the detailed structure of the IVD and EP during maturation and aging in a murine model. Till date, methods to observe the morphological changes in the IVD and EP from rodents have been relatively limited. SRμCT has been recognized as a potential way to visualize the structures containing sclerous and soft tissue. Our study focused on comparing the capacity of SRμCT and μCT in evaluating the detailed structure of the IVD and EP. Both SRμCT and μCT were performed to depict the structure of spinal tissue from 4-month-old mice. Then, the imaging quality was evaluated in the three-dimensional (3D) reconstructed model. Further, the changes in the EP and IVD during the maturation and aging process were assessed morphologically and quantitatively using SRμCT. The 3D reconstructed model of the EP from both μCT and SRμCT provided detailed information on its inner structure. However, the IVD was only depicted using SRμCT. Multi-angle observations of the 3D structure of EP and IVD from mice of different ages (15 days, 2 months, 4 months, and 18 months) were dynamically performed by SRμCT. Quantitative evaluations indicated that the total volume of EP and IVD, the average height of IVD and the canal-total volume ratio of EP increased from 15-day-old mice to 4-month-old mice and decreased in 18-month-old mice. The EP and IVD were clearly visualized using SRμCT. Compared with μCT, SRμCT provided a better ultrahigh resolution image of soft tissue and hard tissue simultaneously, which makes it a promising approach for the noninvasive study of disc degeneration. N /A.

  17. Imaging of the Wormian bones using microcomputed tomography.

    PubMed

    Kozerska, Magdalena; Skrzat, Janusz; Walocha, Jerzy; Wrobel, Andrzej; Leszczynski, Bartosz

    2013-01-01

    Wormian bones are irregular ossicles of small size and reveal fractal pattern of their edges. Their anatomy was visualized in volumetric reconstructions obtained from a series of micro-CT scans. In visual evaluation Wormian bones showed typical anatomy for the calvarial bones. They revealed three-layer composition: the outer and the inner table of the compact bone intervening with the table of the spongy bone. Microcomputed tomography captured all details of the interdigitation of the edge being incorporated into the lambdoid suture and interlocked between opposing edges of the occipital and parietal bones. This modality provided accurate images which allowed delineating morphological differences between the compact bone and the diploe, including vascular channels.

  18. Noise limitations for small-animal microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Ford, Nancy L.; Thornton, Michael M.; Holdsworth, David W.

    2002-05-01

    Recent advances in mouse genomics, including the production of transgenic mouse models, have created an interest in developing non-invasive imaging techniques for small-animal imaging applications. X-ray computed tomography (CT) can provide images with high-resolution isotropic voxels and low noise in relatively short acquisition times. In addition, CT provides volume data set, which allows the viewer to clearly visualize the spatial orientation of tissues within the mouse. We propose a model for an ideal, quantum-noise limited CT scanner for small-animal orientation of tissues within the mouse. We propose a model for an ideal, quantum- noise limited CT scanner for small-animal imaging with the objective of examining the fundamental limits of precision as a function of resolution and dose to the animal. The variance was calculated for several doses and voxel sizes to determine the precision in the linear attenuation coefficient values for the idealized small-animal volume CT scanner. For whole-body exposure of 1.5 Gy, our study predicts precision of +/- 5.8 percent in linear attenuation coefficient, with (0.1 mm)3 isotopic voxels. This work shows the effect of photon noise on the precision that can be expected for micro-computed tomography of small animals in vivo for a given isotopic voxel size and x-ray dose to the animal. The predictions of this work ca be used to design novel imaging systems for use in small-animal research.

  19. Broad Applications for X-Ray Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Lieb-Lappen, R.; Courville, Z.; Albert, D. G.; Taylor, S.; Lever, J.; Barbato, R.; Song, A.; Obbard, R. W.; Fegyveresi, J. M.

    2016-12-01

    The use of x-ray micro-computed tomography (µCT) has exploded over the past decade due to rapid advances in instrumentation technology and accessibility. The primary advantage of μCT is that it provides a non-destructive three-dimensional visualization and characterization of the internal features of a material with spatial resolution down to several microns, or even submicron with x-ray magnification optics available on certain instruments and at some synchrotron beamlines. Commercially available and specially designed benchtop scanners have enabled users to expand the technology to a wide variety of applications. Here we used a Skyscan 1173 scanner housed in a -10 °C cold room to study the microstructure of natural and man-made specimens, including sea ice, snow, firn, ice, soils, leaf litter, permafrost, and explosives. Both qualitatively and quantitatively, we measured the material properties such as open and closed porosity, tortuosity, surface area, volume, degree of anisotropy, structural thickness, topology, and connectivity. Such data helped us answer questions such as: What is the topology and connectivity of brine channels in sea ice? What is the tortuosity of the pore structure in leaf litter? What is the spatial distribution of contaminants in a porous media? Do cracks in explosives aid dissolution of crystals and subsequent contaminant transport into the soil?

  20. Microcomputing.

    ERIC Educational Resources Information Center

    Beiser, Karl

    1986-01-01

    Describes a product--BiblioFile, Library Corporation's catalog production system--and a service--reproduction of public domain software on CD-ROM for sale to those interested--which revolve around the ultra-high-density storage capacity of CD-ROM discs. Criteria for selecting microcomputers are briefly reviewed. (MBR)

  1. Quantitation of microcomputed tomography-imaged ocular microvasculature.

    PubMed

    Atwood, Robert C; Lee, Peter D; Konerding, Moritz A; Rockett, Peter; Mitchell, Christopher A

    2010-01-01

    To quantitatively assess microvascular dimensions in the eyes of neonatal wild-type and VEGF(120)-tg mice, using a novel combination of techniques which permit three-dimensional (3D) image reconstruction. A novel combination of techniques was developed for the accurate 3D imaging of the microvasculature and demonstrated on the hyaloid vasculature of the neonatal mouse eye. Vascular corrosion casting is used to create a stable replica of the vascular network and X-ray microcomputed tomography (muCT) to obtain the 3D images. In-house computer-aided image analysis techniques were then used to perform a quantitative morphological analysis of the images. With the use of these methods, differences in the numbers of vessel segments, their diameter, and volume of vessels in the vitreous compartment were quantitated in wild-type neonatal mice or littermates over-expressing a labile (nonheparin binding) isoform of vascular endothelial growth factor (VEGF(120)) from the developing lens. This methodology was instructive in demonstrating that hyaloid vascular networks in VEGFA(120) over-expressing mice have a 10-fold increase in blind-ended, a six-fold increase in connected vessel segments, in addition to a sixfold increase (0.0314 versus 0.0051 mm(3)) in total vitreous vessel volume compared with wild type. These parameters are not readily quantified via histological, ultrastructural, or stereological analysis. The combination of techniques described here provides the first 3D quantitative characterization of vasculature in an organ system; i.e., the neonatal murine intra-ocular vasculature in both wild-type mice and a transgenic model of lens-specific over-expression of VEGF.

  2. Microcomputed tomography and shock microdeformation studies on shatter cones

    NASA Astrophysics Data System (ADS)

    Zaag, Patrice Tristan; Reimold, Wolf Uwe; Hipsley, Christy Anna

    2016-08-01

    One of the aspects of impact cratering that are still not fully understood is the formation of shatter cones and related fracturing phenomena. Yet, shatter cones have been applied as an impact-diagnostic criterion for decades without the role of shock waves and target rock defects in their formation having been elucidated ever. We have tested the application of the nondestructive microcomputed tomography (μCT) method to visualize the interior of shatter cones in order to possibly resolve links between fracture patterns and shatter cone surface features (striations and intervening "valleys"). Shatter-coned samples from different impact sites and in different lithologies were investigated for their μCT suitability, with a shatter cone in sandstone from the Serra da Cangalha impact structure (Brazil) remaining as the most promising candidate because of the fracture resolution achieved. To validate the obtained CT data, the scanned specimen was cut into three orthogonal sets of thin sections. Scans with 13 μm resolution were obtained. μCT scans and microscopic analysis unraveled an orientation of subplanar fractures and related fluid inclusion trails, and planar fracture (PF) orientations in the interior of shatter cones. Planar deformation features (PDF) were observed predominantly near the shatter cone surface. Previously undescribed varieties of feather features (FF), in the form of lamellae emanating from curviplanar and curved fractures, as well as an "arrowhead"-like FF development with microlamellae originating from both sides of a PF, were observed. The timing of shatter cone formation was investigated by establishing temporal relations to the generation of various shock microscopic effects. Shatter cones are, thus, generated post- or syn-formation of PF, FF, subplanar fractures, and PDF. The earliest possible time for shatter cone formation is during the late stage of the compressional phase, that is, shock wave passage, of an impact event.

  3. Visualization of Three-Dimensional Nephron Structure With Microcomputed Tomography

    SciTech Connect

    Bentley,M.; Jorgensen, S.; Lerman, L.; Ritman, E.; Romero, J.

    2007-01-01

    The three-dimensional architecture of nephrons in situ and their interrelationship with other nephrons are difficult to visualize by microscopic methods. The present study uses microcomputed X-ray tomography (micro-CT) to visualize intact nephrons in situ. Rat kidneys were perfusion-fixed with buffered formalin and their vasculature was subsequently perfused with radiopaque silicone. Cortical tissue was stained en bloc with osmium tetroxide, embedded in plastic, scanned, and reconstructed at voxel resolutions of 6, 2, and 1 {mu}m. At 6 {mu}m resolution, large blood vessels and glomeruli could be visualized but nephrons and their lumens were small and difficult to visualize. Optimal images were obtained using a synchrotron radiation source at 2 {mu}m resolution where nephron components could be identified, correlated with histological sections, and traced. Proximal tubules had large diameters and opaque walls, whereas distal tubules, connecting tubules, and collecting ducts had smaller diameters and less opaque walls. Blood vessels could be distinguished from nephrons by the luminal presence of radiopaque silicone. Proximal tubules were three times longer than distal tubules. Proximal and distal tubules were tightly coiled in the outer cortex but were loosely coiled in the middle and inner cortex. The connecting tubules had the narrowest diameters of the tubules and converged to form arcades that paralleled the radial vessels as they extended to the outer cortex. These results illustrate a potential use of micro-CT to obtain three-dimensional information about nephron architecture and nephron interrelationships, which could be useful in evaluating experimental tubular hypertrophy, atrophy, and necrosis.

  4. A skeleton-tree-based approach to acinar morphometric analysis using microcomputed tomography with comparison of acini in young and old C57BL/6 mice.

    PubMed

    Kizhakke Puliyakote, Abhilash S; Vasilescu, Dragoş M; Sen Sharma, Kriti; Wang, Ge; Hoffman, Eric A

    2016-06-15

    We seek to establish a method using interior tomographic techniques (Xradia MicroXCT-400) for acinar morphometric analysis using the pathway center lines from micro X-ray computed tomographic (Micro-CT) images as the road map. Through the application of these techniques, we present a method to extend the atlas of murine lungs to acinar levels and present a comparison between two age groups of the C57BL/6 strain. Lungs fixed via vascular perfusion were scanned using high-resolution Micro-CT protocols. Individual acini were segmented, and skeletonized paths to alveolar sacs from the entrance to the acinus were formed. Morphometric parameters, including branch lengths, diameters, and branching angles, were generated. Six mice each, at two age groups (∼20 and ∼90 wk of age), were studied. Additive Gaussian noise (0 mean and SD 1, 2, 5, and 10) was used to test the robustness of the analytical method. Noise-based variations were within ±6 μm for branch lengths and ±5 μm for diameters. At a noise level of 10, errors increased. Branch diameters were less susceptible to noise than lengths. There was >95% center line overlap across all noise levels. The measurements obtained using the center lines as a road map were not affected by added noise. Acini from younger mice had smaller branch diameters and lengths at all generations without significant differences in branching angles. The relative distribution of volume in the alveolar ducts was similar across both age groups. The method has been demonstrated to be repeatable and robust to image noise and provides a new, nondestructive technique to assess and compare acinar morphometry quantitatively.

  5. A microcomputed tomography guided fluorescence tomography system for small animal molecular imaging

    PubMed Central

    Kepshire, Dax; Mincu, Niculae; Hutchins, Michael; Gruber, Josiah; Dehghani, Hamid; Hypnarowski, Justin; Leblond, Frederic; Khayat, Mario; Pogue, Brian W.

    2009-01-01

    A prototype small animal imaging system was created for coupling fluorescence tomography (FT) with x-ray microcomputed tomography (microCT). The FT system has the potential to provide synergistic information content resultant from using microCT images as prior spatial information and then allows overlay of the FT image onto the original microCT image. The FT system was designed to use single photon counting to provide maximal sensitivity measurements in a noncontact geometry. Five parallel detector locations are used, each allowing simultaneous sampling of the fluorescence and transmitted excitation signals through the tissue. The calibration and linearity range performance of the system are outlined in a series of basic performance tests and phantom studies. The ability to image protoporphyrin IX in mouse phantoms was assessed and the system is ready for in vivo use to study biological production of this endogenous marker of tumors. This multimodality imaging system will have a wide range of applications in preclinical cancer research ranging from studies of the tumor microenvironment and treatment efficacy for emerging cancer therapeutics. PMID:19405660

  6. A microcomputed tomography guided fluorescence tomography system for small animal molecular imaging

    SciTech Connect

    Kepshire, Dax; Gruber, Josiah; Hypnarowski, Justin; Leblond, Frederic; Pogue, Brian W.; Mincu, Niculae; Hutchins, Michael; Khayat, Mario; Dehghani, Hamid

    2009-04-15

    A prototype small animal imaging system was created for coupling fluorescence tomography (FT) with x-ray microcomputed tomography (microCT). The FT system has the potential to provide synergistic information content resultant from using microCT images as prior spatial information and then allows overlay of the FT image onto the original microCT image. The FT system was designed to use single photon counting to provide maximal sensitivity measurements in a noncontact geometry. Five parallel detector locations are used, each allowing simultaneous sampling of the fluorescence and transmitted excitation signals through the tissue. The calibration and linearity range performance of the system are outlined in a series of basic performance tests and phantom studies. The ability to image protoporphyrin IX in mouse phantoms was assessed and the system is ready for in vivo use to study biological production of this endogenous marker of tumors. This multimodality imaging system will have a wide range of applications in preclinical cancer research ranging from studies of the tumor microenvironment and treatment efficacy for emerging cancer therapeutics.

  7. Microcomputed tomography characterization of shoulder osseous deformity after brachial plexus birth palsy: a rat model study.

    PubMed

    Li, Zhongyu; Barnwell, Jonathan; Tan, Josh; Koman, L Andrew; Smith, Beth P

    2010-11-03

    Shoulder deformities are common secondary sequelae associated with brachial plexus birth palsy. The aim of the present study was to characterize three-dimensional glenohumeral deformity associated with brachial plexus birth palsy with use of microcomputed tomography scanning in a recently developed animal model. Brachial plexus birth palsy was produced by a right-sided neurotomy of the C5 and C6 nerve roots in seven five-day-old Sprague-Dawley rats. Microcomputed tomography scanning was performed when the rats were four months of age. Glenoid size, version, and inclination; humeral head size; and acromion-glenoid distance were measured. Normal shoulders of age-matched rats (n = 9) served as controls. Statistical analysis was performed with use of the unpaired two-tailed Student t test. There were significant increases in glenoid retroversion (-7.6° ± 4.9° compared with 3.6° ± 2.1°; p = 0.038) and glenoid inclination (38.7° ± 7.3° compared with 11.2° ± 1.9°; p = 0.015) in the shoulders with simulated brachial plexus birth palsy in comparison with the normal, control shoulders. The glenohumeral joints were more medialized in the joints with simulated brachial plexus birth palsy as reflected by the acromion-glenoid distance measurement; however, the difference was not significant (3.20 ± 0.51 compared with 2.40 ± 0.18 mm; p = 0.12). Although the mean humeral head height and width measurements, on the average, were smaller in the brachial plexus birth palsy shoulders as compared with the normal, control shoulders, only the measurement of humeral head height was significantly different between the two groups (4.25 ± 2.02 compared with 4.97 ± 0.11 mm [p = 0.008] and 3.56 ± 0.27 compared with 4.19 ± 0.17 mm [p = 0.056], respectively). In this animal model, rats with simulated brachial plexus birth palsy developed gross architectural joint distortion characterized by increased glenoid retroversion and inclination. In addition, humeral heads tended to be

  8. Microcomputed Tomography Evaluation of Polymerization Shrinkage of Class I Flowable Resin Composite Restorations.

    PubMed

    Sampaio, C S; Chiu, K-J; Farrokhmanesh, E; Janal, M; Puppin-Rontani, R M; Giannini, M; Bonfante, E A; Coelho, P G; Hirata, R

    The present study aimed to characterize the pattern and volume of polymerization shrinkage of flowable resin composites, including one conventional, two bulk fill, and one self-adhesive. Standardized class I preparations (2.5 mm depth × 4 mm length × 4 mm wide) were performed in 24 caries-free human third molars that were randomly divided in four groups, according to the resin composite and adhesive system used: group 1 = Permaflo + Peak Universal Bond (PP); group 2 = Filtek Bulk Fill + Scotchbond Universal (FS); group 3 = Surefil SDR + XP Bond (SX); and group 4 = Vertise flow self-adhering (VE) (n=6). Each tooth was scanned three times using a microcomputed tomography (μCT) apparatus. The first scan was done after the cavity preparation, the second after cavity filling with the flowable resin composite before curing, and the third after it was cured. The μCT images were imported into three-dimensional rendering software, and volumetric polymerization shrinkage percentage was calculated for each sample. Data were submitted to one-way analysis of variance and post hoc comparisons. No significant difference was observed among PP, FS, and VE. SX bulk fill resin composite presented the lowest values of volumetric shrinkage. Shrinkage was mostly observed along the occlusal surface and part of the pulpal floor. In conclusion, polymerization shrinkage outcomes in a 2.5-mm deep class I cavity were material dependent, although most materials did not differ. The location of shrinkage was mainly at the occlusal surface.

  9. Ceramic and polymeric dental onlays evaluated by photo-elasticity, optical coherence tomography, and micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda; Topala, Florin; Ionita, Ciprian; Negru, Radu; Fabriky, Mihai; Marcauteanu, Corina; Bradu, Adrian; Dobre, George; Marsavina, Liviu; Rominu, Mihai; Podoleanu, Adrian

    2011-10-01

    Dental onlays are restorations used to repair rear teeth that have a mild to moderate amount of decay. They can also be used to restore teeth that are cracked or fractured if the damage is not severe enough to require a dental crown. The use of onlays requires less tooth reduction than does the use of metal fillings. This allows dentists to conserve more of a patient's natural tooth structure in the treatment process. The aims of this study are to evaluate the biomechanical comportment of the dental onlays, by using the 3D photo elasticity method and to investigate the integrity of the structures and their fitting to the dental support. For this optical coherence tomography and micro-computed tomography were employed. Both methods were used to investigate 37 dental onlays, 17 integral polymeric and 20 integral ceramic. The results permit to observe materials defects inside the ceramic or polymeric onlays situate in the biomechanically tensioned areas that could lead to fracture of the prosthetic structure. Marginal fitting problems of the onlays related to the teeth preparations were presented in order to observe the possibility of secondary cavities. The resulted images from the optical coherence tomography were verified by the micro-computed tomography. In conclusion, the optical coherence tomography can be used as a clinical method in order to evaluate the integrity of the dental ceramic and polymeric onlays and to investigate the quality of the marginal fitting to the teeth preparations.

  10. Combined system of fluorescence diffuse optical tomography and microcomputed tomography for small animal imaging

    NASA Astrophysics Data System (ADS)

    Yang, Xiaoquan; Gong, Hui; Quan, Guotao; Deng, Yong; Luo, Qingming

    2010-05-01

    We developed a dual-modality system that combines fluorescence diffuse optical tomography (fDOT) and flat panel detector-based microcomputed tomography (micro-CT) to simultaneously reveal molecular and structural information in small animals. In fDOT, a 748 nm diode laser was used as an excitation source, while a cooled charge coupled device camera was adopted to collect transmission fluorescence. In micro-CT, a flat panel detector based on amorphous silicon, with active area of 13×13 cm2, and a microfocus x-ray tube were used. The fDOT system was mounted orthogonally to the micro-CT and the projection images were acquired without rotation of the sample, which is different from the method used for micro-CT alone. Both the finite element method and the algebraic reconstruction technique were used to reconstruct images from the fDOT. Phantom data showed that the resolution of the fDOT system was about 3 mm at an imaging depth of 7 mm. Quantitative error was no more than 5% and imaging sensitivity for 1,1'-dioctadecyl-3,3,3',3'-etramethylindotricarbocyanine iodide bis-oleate (DiR-BOA) was estimated to be higher than 100 nM at a depth of 7 mm. Calculations of the phantom's center of mass showed that the location accuracy of fDOT was about 0.7 mm. We applied a Feldkamp algorithm to reconstruct the micro-CT image. By measuring the presampled modulation transfer function with a 30 μm tungsten thread, we estimated that the micro-CT has a resolution of 5 mm-1 when the field of view was 6.5 cm. Our results indicate the uniformity of the transaxial micro-CT image and the contrast-to-noise ratio was measured as 1.95 for a radiation dose of 1 cGy. A non-image-based method was employed for merging images from the two imaging modalities. A nude mouse with DiR-BOA, imaged ex vivo, was used to validate the feasibility of the dual-modality system.

  11. Assessment of Viability of Human Fat Injection into Nude Mice with Micro-Computed Tomography

    PubMed Central

    Chung, Michael T.; McArdle, Adrian; Senarath-Yapa, Kshemendra; Zielins, Elizabeth R.; Tevlin, Ruth; Duldulao, Christopher R.; Walmsley, Graham G.; Wearda, Taylor; Marecic, Owen; Longaker, Michael T.; Wan, Derrick C.

    2015-01-01

    Lipotransfer is a vital tool in the surgeon’s armamentarium for the treatment of soft tissue deficits of throughout the body. Fat is the ideal soft tissue filler as it is readily available, easily obtained, inexpensive, and inherently biocompatible.1 However, despite its burgeoning popularity, fat grafting is hampered by unpredictable results and variable graft survival, with published retention rates ranging anywhere from 10-80%. 1-3 To facilitate investigations on fat grafting, we have therefore developed an animal model that allows for real-time analysis of injected fat volume retention. Briefly, a small cut is made in the scalp of a CD-1 nude mouse and 200-400 µl of processed lipoaspirate is placed over the skull. The scalp is chosen as the recipient site because of its absence of native subcutaneous fat, and because of the excellent background contrast provided by the calvarium, which aids in the analysis process. Micro-computed tomography (micro-CT) is used to scan the graft at baseline and every two weeks thereafter. The CT images are reconstructed, and an imaging software is used to quantify graft volumes. Traditionally, techniques to assess fat graft volume have necessitated euthanizing the study animal to provide just a single assessment of graft weight and volume by physical measurement ex vivo. Biochemical and histological comparisons have likewise required the study animal to be euthanized. This described imaging technique offers the advantage of visualizing and objectively quantifying volume at multiple time points after initial grafting without having to sacrifice the study animal. The technique is limited by the size of the graft able to be injected as larger grafts risk skin and fat necrosis. This method has utility for all studies evaluating fat graft viability and volume retention. It is particularly well-suited to providing a visual representation of fat grafts and following changes in volume over time. PMID:25590561

  12. Access cavity preparation training using haptic virtual reality and microcomputed tomography tooth models.

    PubMed

    Suebnukarn, S; Hataidechadusadee, R; Suwannasri, N; Suprasert, N; Rhienmora, P; Haddawy, P

    2011-11-01

    To evaluate the effectiveness of haptic virtual reality (VR) simulator training using microcomputed tomography (micro-CT) tooth models on minimizing procedural errors in endodontic access preparation. Fourth year dental students underwent a pre-training assessment of access cavity preparation on an extracted maxillary molar tooth mounted on a phantom head. Students were then randomized to training on either the micro-CT tooth models with a haptic VR simulator (n = 16) or extracted teeth in a phantom head (n = 16) training environments for 3 days, after which the assessment was repeated. The main outcome measure was procedural errors assessed by an expert blinded to trainee and training status. The secondary outcome measures were tooth mass loss and task completion time. The Wilcoxon test was used to examine the differences between pre-training and post-training error scores, on the same group. The Mann-Whitney test was used to detect any differences between haptic VR training and phantom head training groups. The independent t-test was used to make a comparison on tooth mass removed and task completion time between the haptic VR training and phantom head training groups. Post-training performance had improved compared with pre-training performance in error scores in both groups (P < 0.05). However, error score reduction between the haptic VR simulator and the conventional training group was not significantly different (P > 0.05). The VR simulator group decreased significantly (P < 0.05) the amount of hard tissue volume lost on the post-training exercise. Task completion time was not significantly different (P > 0.05) in both groups. Training on the haptic VR simulator and conventional phantom head had equivalent effects on minimizing procedural errors in endodontic access cavity preparation. © 2011 International Endodontic Journal.

  13. Inside marginal adaptation of crowns by X-ray micro-computed tomography

    SciTech Connect

    Dos Santos, T. M.; Lima, I.; Lopes, R. T.; Author, S. B. Jr.

    2015-07-01

    The objective of this work was to access dental arcade by using X-ray micro-computed tomography. For this purpose high resolution system was used and three groups were studied: Zirkonzahn CAD-CAM system, IPS e.max Press, and metal ceramic. The three systems assessed in this study showed results of marginal and discrepancy gaps clinically accepted. The great result of 2D and 3D evaluations showed that the used technique is a powerful method to investigate quantitative characteristics of dental arcade. (authors)

  14. 3D image reconstruction on x-ray micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Louk, Andreas C.

    2015-03-01

    A model for 3D image reconstruction of x-ray micro-computed tomography scanner (micro-CTScan) has been developed. A small object has been put under inspection on an x-ray micro-CTScan. The object cross-section was assumed on the x-y plane, while its height was along the z-axis. Using a radiography plane detector, a set of digital radiographs represents multiple angle of views from 0º to 360º with an interval of 1º was obtained. Then, a set of crosssectional tomography, slice by slice was reconstructed. At the end, all image slices were stacked together sequentially to obtain a 3D image model of the object being inspected. From this development, lessons on the way to have better understanding on the internal structure of the object can be approached based on the cross-sectional image slice by slice and surface skin.

  15. Angiofil-mediated visualization of the vascular system by microcomputed tomography: a feasibility study.

    PubMed

    Grabherr, Silke; Hess, Andreas; Karolczak, Marek; Thali, Michael J; Friess, Sebastian D; Kalender, Willi A; Dirnhofer, Richard; Djonov, Valentin

    2008-07-01

    Visualization of the vascular systems of organs or of small animals is important for an assessment of basic physiological conditions, especially in studies that involve genetically manipulated mice. For a detailed morphological analysis of the vascular tree, it is necessary to demonstrate the system in its entirety. In this study, we present a new lipophilic contrast agent, Angiofil, for performing postmortem microangiography by using microcomputed tomography. The new contrast agent was tested in 10 wild-type mice. Imaging of the vascular system revealed vessels down to the caliber of capillaries, and the digital three-dimensional data obtained from the scans allowed for virtual cutting, amplification, and scaling without destroying the sample. By use of computer software, parameters such as vessel length and caliber could be quantified and remapped by color coding onto the surface of the vascular system. The liquid Angiofil is easy to handle and highly radio-opaque. Because of its lipophilic abilities, it is retained intravascularly, hence it facilitates virtual vessel segmentation, and yields an enduring signal which is advantageous during repetitive investigations, or if samples need to be transported from the site of preparation to the place of actual analysis, respectively. These characteristics make Angiofil a promising novel contrast agent; when combined with microcomputed tomography, it has the potential to turn into a powerful method for rapid vascular phenotyping.

  16. Three-dimensional registration of synchrotron radiation-based micro-computed tomography images with advanced laboratory micro-computed tomography data from murine kidney casts

    NASA Astrophysics Data System (ADS)

    Thalmann, Peter; Hieber, Simone E.; Schulz, Georg; Deyhle, Hans; Khimchenko, Anna; Kurtcuoglu, Vartan; Olgac, Ufuk; Marmaras, Anastasios; Kuo, Willy; Meyer, Eric P.; Beckmann, Felix; Herzen, Julia; Ehrbar, Stefanie; Müller, Bert

    2014-09-01

    Malfunction of oxygen regulation in kidney and liver may lead to the pathogenesis of chronic diseases. The underlying mechanisms are poorly understood. In kidney, it is hypothesized that renal gas shunting from arteries to veins eliminates excess oxygen. Such shunting is highly dependent on the structure of the renal vascular network. The vascular tree has so far not been quantified under maintenance of its connectivity as three-dimensional imaging of the vessel tree down to the smallest capillaries, which in mouse model are smaller than 5 μm in diameter, is a challenging task. An established protocol uses corrosion casts and applies synchrotron radiation-based micro-computed tomography (SRμCT), which provides the desired spatial resolution with the necessary contrast. However, SRμCT is expensive and beamtime access is limited. We show here that measurements with a phoenix nanotomrm (General Electric, Wunstorf, Germany) can provide comparable results to those obtained with SRμCT, except for regions with small vessel structures, where the signal-to-noise level was significantly reduced. For this purpose the nanotom®m measurement was compared with its corresponding measurement acquired at the beamline P05 at PETRA III at DESY, Hamburg, Germany.

  17. Application of micro-computed tomography to microstructure studies of the medicinal fungus Hericium coralloides.

    PubMed

    Pallua, Johannes D; Kuhn, Volker; Pallua, Anton F; Pfaller, Kristian; Pallua, Anton K; Recheis, Wolfgang; Pöder, Reinhold

    2015-01-01

    The potential of 3-D nondestructive imaging techniques such as micro-computed tomography (micro-CT) was evaluated to study morphological patterns of the potential medicinal fungus Hericium coralloides (Basidiomycota). Micro-CT results were correlated with histological information gained from scanning electron microscopy (SEM) and light microscopy (LM). It is demonstrated that the combination of these imaging methods results in a more distinct picture of the morphology of the edible and potentially medicinal Hericium coralloides basidiomata. In addition we have created 3-D reconstructions and visualizations based on micro-CT imagery from a randomly selected part of the upper region of a fresh H. coralloides basidioma: Analyses for the first time allowed an approximation of the evolutionary effectiveness of this bizarrely formed basidioma type in terms of the investment of tissue biomass and its reproductive output (production of basidiospores). © 2015 by The Mycological Society of America.

  18. Quantitative morphometric evaluation of critical size experimental bone defects by microcomputed tomography.

    PubMed

    Efeoglu, Candan; Fisher, Sheila E; Ertürk, Selda; Oztop, Fikri; Günbay, Sevtap; Sipahi, Aylin

    2007-04-01

    Our aim was to show that microcomputed tomography is a useful tool for acquiring high-resolution three-dimensional tomographic images to assess bone healing, the interface with materials, and the biocompatibility of bone substitutes. Acquired images can be used for non-invasive quantitative morphometric analysis of regenerating bone, leaving the option for conventional histology to be an adjunct used at defined intervals. The temporal characterisation of the mineralisation of bone potentially has a critical role in the understanding of the dynamics of mineralisation of healing bone. This has applications both for degradable and bioactive materials and for pharmaceutical products that act on bone. Formal validation of this promising new technique will be a critical part of continuing studies.

  19. Mapping the calcification of bovine pericardium in rat model by enhanced micro-computed tomography.

    PubMed

    Liu, Jing; Zhong, Shengping; Lan, Hualin; Meng, Xu; Zhang, Haibo; Fan, Yubo; Wang, Yuxing; Wang, Chunren; Wang, Zhaoxu

    2014-09-01

    The calcification initiation and progression of bioprosthetic heart valve were investigated in a rat model by enhanced micro-computed tomography, together with histologic study and scanning electron microscope analysis. The implantation data at early stage showed apparent dendritic patterns in the radiographic images for the glutaraldehyde-treated bovine pericardium and this dendritic pattern was verified to be associated with the vessel distribution in the tissue. Histologic study and scanning electron microscope analysis both indicated that the calcium deposits in the pericardium vessels regions were more grievous than those scattered in the collagen fibers in the first two weeks after implantation. Subsequently, calcification spreaded and the entire sample was severely calcified in 60 days.

  20. Micro-computed tomography imaging and analysis in developmental biology and toxicology.

    PubMed

    Wise, L David; Winkelmann, Christopher T; Dogdas, Belma; Bagchi, Ansuman

    2013-06-01

    Micro-computed tomography (micro-CT) is a high resolution imaging technique that has expanded and strengthened in use since it was last reviewed in this journal in 2004. The technology has expanded to include more detailed analysis of bone, as well as soft tissues, by use of various contrast agents. It is increasingly applied to questions in developmental biology and developmental toxicology. Relatively high-throughput protocols now provide a powerful and efficient means to evaluate embryos and fetuses subjected to genetic manipulations or chemical exposures. This review provides an overview of the technology, including scanning, reconstruction, visualization, segmentation, and analysis of micro-CT generated images. This is followed by a review of more recent applications of the technology in some common laboratory species that highlight the diverse issues that can be addressed.

  1. Void and gap evaluation using microcomputed tomography of different fiber post cementation techniques.

    PubMed

    Caceres, Eduardo A; Sampaio, Camila S; Atria, Pablo J; Moura, Helora; Giannini, Marcelo; Coelho, Paulo G; Hirata, Ronaldo

    2017-04-28

    Few studies have investigated the voids and gaps produced during the cementation of fiber posts using different techniques. The purpose of this study was to evaluate and quantify void and gap area formations of different fiber post cementation techniques using microcomputed tomography (μCT). Standardized endodontically treated acrylic resin roots (N=24) were divided into 4 groups (n=6) according to different fiber posts cemented with the resin cement (FB); fiber posts relined with composite resin followed by cementation (FBR); fiber posts cemented using an ultrasonic device (FBU); and fiber posts relined with composite resin and cemented using an ultrasonic device (FBRU). Each specimen was scanned twice using micro-computed tomography (μCT; empty root, followed by after fiber post cementation). Digital imaging and communications in medicine (DICOM) files were transferred into 3-dimensional (3D) reconstruction software for analysis. Void volume in the cementation system and gap area formation were evaluated; quantitative and qualitative analyses were performed. The data were analyzed using 2-way ANOVA and the Tukey honest significant difference post hoc test (α=.05). FBR showed a lower percentage of voids than obtained for FB (P<.05). Groups FB, FBU, and FBRU did not show significant difference in void formation (P>.05). No significant differences were found in gap area formations among the experimental groups (P>.05). The use of a composite resin to reline the fiber post significantly decreased the void formation in the cementation procedure when no ultrasonic device was used. The use of an ultrasonic device did not decrease the percentage of void or gap formation for any technique evaluated. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

  2. Resolution effect in X-ray microcomputed tomography imaging and small pore's contribution to permeability for a Berea sandstone

    NASA Astrophysics Data System (ADS)

    Peng, Sheng; Marone, Federica; Dultz, Stefan

    2014-03-01

    Resolution selection when using X-ray microcomputed tomography should be made based on the compromise between accuracy and representativeness. The question is then how accurate is accurate enough, that is, how small a pore is small enough to be ignored without generating misleading results on pore representation and subsequent flow properties such as permeability. In this study, synchrotron X-ray microcomputed tomographic scans of a Berea sandstone sample were acquired for two resolutions (with 1.85 and 5.92 μm pixel width). Higher resolution images resolve more small pores, and have similar large pores as the lower resolution images. Pore characterization and permeability estimation were conducted based on these two sets of images. The pore parameters and permeability were also measured for another larger sample from the same rock fragment through laboratory experiments. The comparison between the different resolution image analyses and the laboratory measurement indicates that small pores contribute to larger porosity, smaller tortuosity, and larger surface area, but do not influence permeability significantly. Therefore, relatively low resolution (pixel width up to 5.92 μm) can be used for Berea sandstone when permeability is the focus. However, use of even lower resolution needs to be careful since lower resolution not only excludes more small pores, but also has the potential to overestimate the pore size and thereby the permeability. Kozeny-Carman equation was used to estimate the permeability with geometric and diffusional tortuosity. The results indicate that the latter tortuosity can serve better for the permeability estimation than the former.

  3. Hierarchical bioimaging and quantification of vasculature in disease models using corrosion casts and microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Heinzer, Stefan; Krucker, Thomas; Stampanoni, Marco; Abela, Rafael; Meyer, Eric P.; Schuler, Alexandra; Schneider, Philipp; Muller, Ralph

    2004-10-01

    A wide range of disorders are associated with alterations of the central and peripheral vascular system. Modified vascular corrosion casting using a newly developed polymer, allows for the first time hierarchical assessment of 3D vessel data in animals down to the level of capillaries. Imaging of large volumes of vasculature at intermediate resolution (16 um) was performed using a desktop micro-computed tomography system. Subsequently regions of interest were identified for additional high resolution imaging (1.4 um) at the X-ray Tomographic Microscopy (XTM) station of the Swiss Light Source (SLS). A framework for systematic hierarchical imaging and quantification was developed. Issues addressed included enhanced XTM data acquisition, introduction of local tomography, sample navigation, advanced post processing, and data combination. In addition to visual assessment of qualitative changes, morphometrical and architectural indices were determined using direct 3D morphometry software developed in house. Vessel specific parameters included thickness, surface, connectivity, and vessel length. Reconstructions of cerebral vasculature in mutant mice modeling Alzheimer's disease revealed significant changes in vessel architecture and morphology. In the future, a combination of these techniques may support drug discovery. Additionally, future ultra-high-resolution in vivo systems may even allow non-invasive tracking of temporal alterations in vascular morphology.

  4. Micro-computed tomography: Introducing new dimensions to taxonomy

    PubMed Central

    Faulwetter, Sarah; Vasileiadou, Aikaterini; Kouratoras, Michail; Thanos Dailianis; Arvanitidis,  Christos

    2013-01-01

    Abstract Continuous improvements in the resolution of three-dimensional imaging have led to an increased application of these techniques in conventional taxonomic research in recent years. Coupled with an ever increasing research effort in cybertaxonomy, three-dimensional imaging could give a boost to the development of virtual specimen collections, allowing rapid and simultaneous access to accurate virtual representations of type material. This paper explores the potential of micro-computed tomography (X-ray micro-tomography), a non-destructive three-dimensional imaging technique based on mapping X-ray attenuation in the scanned object, for supporting research in systematics and taxonomy. The subsequent use of these data as virtual type material, so-called “cybertypes”, and the creation of virtual collections lie at the core of this potential. Sample preparation, image acquisition, data processing and presentation of results are demonstrated using polychaetes (bristle worms), a representative taxon of macro-invertebrates, as a study object. Effects of the technique on the morphological, anatomical and molecular identity of the specimens are investigated. The paper evaluates the results and discusses the potential and the limitations of the technique for creating cybertypes. It also discusses the challenges that the community might face to establish virtual collections. Potential future applications of three-dimensional information in taxonomic research are outlined, including an outlook to new ways of producing, disseminating and publishing taxonomic information. PMID:23653515

  5. Semi-automatic segmentation of subcutaneous tumours from micro-computed tomography images

    NASA Astrophysics Data System (ADS)

    Ali, Rehan; Gunduz-Demir, Cigdem; Szilágyi, Tünde; Durkee, Ben; Graves, Edward E.

    2013-11-01

    This paper outlines the first attempt to segment the boundary of preclinical subcutaneous tumours, which are frequently used in cancer research, from micro-computed tomography (microCT) image data. MicroCT images provide low tissue contrast, and the tumour-to-muscle interface is hard to determine, however faint features exist which enable the boundary to be located. These are used as the basis of our semi-automatic segmentation algorithm. Local phase feature detection is used to highlight the faint boundary features, and a level set-based active contour is used to generate smooth contours that fit the sparse boundary features. The algorithm is validated against manually drawn contours and micro-positron emission tomography (microPET) images. When compared against manual expert segmentations, it was consistently able to segment at least 70% of the tumour region (n = 39) in both easy and difficult cases, and over a broad range of tumour volumes. When compared against tumour microPET data, it was able to capture over 80% of the functional microPET volume. Based on these results, we demonstrate the feasibility of subcutaneous tumour segmentation from microCT image data without the assistance of exogenous contrast agents. Our approach is a proof-of-concept that can be used as the foundation for further research, and to facilitate this, the code is open-source and available from www.setuvo.com.

  6. Compression-recovery model of absorptive glass mat (AGM) separator guided by X-ray micro-computed tomography analysis

    NASA Astrophysics Data System (ADS)

    Kameswara Rao, P. V.; Rawal, Amit; Kumar, Vijay; Rajput, Krishn Gopal

    2017-10-01

    Absorptive glass mat (AGM) separators play a key role in enhancing the cycle life of the valve regulated lead acid (VRLA) batteries by maintaining the elastic characteristics under a defined level of compression force with the plates of the electrodes. Inevitably, there are inherent challenges to maintain the required level of compression characteristics of AGM separators during the charge and discharge of the battery. Herein, we report a three-dimensional (3D) analytical model for predicting the compression-recovery behavior of AGM separators by formulating a direct relationship with the constituent fiber and structural parameters. The analytical model of compression-recovery behavior of AGM separators has successfully included the fiber slippage criterion and internal friction losses. The presented work uses, for the first time, 3D data of fiber orientation from X-ray micro-computed tomography, for predicting the compression-recovery behavior of AGM separators. A comparison has been made between the theoretical and experimental results of compression-recovery behavior of AGM samples with defined fiber orientation characteristics. In general, the theory agreed reasonably well with the experimental results of AGM samples in both dry and wet states. Through theoretical modeling, fiber volume fraction was established as one of the key structural parameters that modulates the compression hysteresis of an AGM separator.

  7. Pulp pathosis in inlayed teeth of the ancient Mayas: a microcomputed tomography study.

    PubMed

    Versiani, M A; Sousa-Neto, M D; Pécora, J D

    2011-11-01

    To evaluate three-dimensionally, using microcomputed tomography (μCT), the anatomical relationship between the cavity prepared to hold the inlay stone and the pulp chamber in the teeth of the ancient Maya. Six well-preserved teeth from Maya corpses found in an archaeological site in Guatemala (approximately 1600 year old) were selected and scanned using a high-resolution μCT system (SkyScan 1174v2; SkyScan N.V., Kontich, Belgium). The sample comprised six maxillary teeth: two canines, one premolar, two central incisors and one lateral incisor. All teeth had one or two inlay stones on the buccal surface of the crown. Each specimen was scanned at an isotropic resolution of 22.5 μm, a rotational step of 0.70°, a rotational angle of 180° and a 3.1-s exposure time, using a 1-mm-thick aluminium filter. Images of each specimen were reconstructed from apex to the crown with dedicated software (NRecon v1.6.1.5) in approximately 450 slices. CTan v1.11 and CTVol v2.1 were used for three-dimensional visualization and qualitative analysis of the external and internal anatomy of the teeth. The tooth modification in all samples was classified as type E1 (one stone on the buccal surface of the crown) or E2 (two stones on the buccal surface of the crown). In the canine teeth, the cavities created to insert the inlay stone did not reach the pulp chamber. Conversely, in the maxillary incisors, the cavities clearly perforated the pulp chamber resulting in massive internal inflammatory resorption or partial calcification of the pulp cavity. In the premolar tooth, a small perforation of the pulp chamber under the buccal cusp, without morphological alteration of the intraradicular dentine, was observed. Microcomputed tomography analysis of teeth of the ancient Maya civilization showed that the inlay cavities cut reached the pulp chamber in the maxillary incisors and premolar teeth, with the potential to cause pulp and periapical disease. © 2011 International Endodontic Journal.

  8. Quantification and characterization of radiation-induced changes to mandibular vascularity using micro-computed tomography.

    PubMed

    Deshpande, Sagar Satish; Donneys, Alexis; Farberg, Aaron Samuel; Tchanque-Fossuo, Catherine N; Felice, Peter A; Buchman, Steven Richard

    2014-01-01

    Perhaps the most vexing and exigent problem confronting head and neck cancer reconstruction is overcoming the impediments of collateral damage imposed by radiation therapy (XRT) on normal surrounding tissue. Radiation therapy is detrimental to bone and soft tissue repair resulting in an unacceptably high incidence of devastating wound healing complications as well as the associated morbidity of late pathologic fractures, reduced bone healing, and osteoradionecrosis. The consequences of XRT on bone vasculature, long known to be affected by radiation, have been poorly understood. The purpose of this study was to analyze the degree by which irradiation degrades existing bone vascularity using a powerful micro-computed tomography technique to attain highly precise quantitative metrics of the vascular tree. Fourteen 400-g male Sprague-Dawley rats underwent 35 Gy of fractionated XRT at 7 Gy/d. The animals were euthanized after 28 days, and the left ventricle was fixed and injected with Microfil (MV-122; Flow Tech, Carver, Mass) contrast. Left hemimandibles were dissected and scanned using high-resolution micro-computed tomography (18-μm voxels). The vessel number, thickness, separation, connectivity, and vessel volume fraction were analyzed for the region of interest, defined to be the volume behind the third molar spanning a total distance of 5.1 mm. Stereologic analysis and subsequent analysis of variance test demonstrated a significant and quantifiable diminution in the irradiated vasculature when compared with control animals. The vessel volume fraction (0.016 vs 0.032, P ≤ 0.003) and vessel thickness (0.042 vs 0.067 mm, P ≤ 0.001) were markedly reduced. Interestingly, further analysis demonstrated no significant differences between vessel separation and vessel number. The results of our study specifically quantify the corrosive affects of XRT on the vasculature of the mandible. The data from this novel technique go even further and imply retention of blood

  9. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography

    PubMed Central

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-01-01

    Background Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Material/Methods Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. Results ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Conclusions Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal. PMID:26092929

  10. Evaluation of Root Canal Preparation Using Rotary System and Hand Instruments Assessed by Micro-Computed Tomography.

    PubMed

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Muhaxheri, Edmond

    2015-06-20

    Complete mechanical preparation of the root canal system is rarely achieved. Therefore, the purpose of this study was to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files using micro-computed tomography. Sixty extracted upper second premolars were selected and divided into 2 groups of 30 teeth each. Before preparation, all samples were scanned by micro-computed tomography. Thirty teeth were prepared with the ProTaper system and the other 30 with stainless steel files. After preparation, the untouched surface and root canal straightening were evaluated with micro-computed tomography. The percentage of untouched root canal surface was calculated in the coronal, middle, and apical parts of the canal. We also calculated straightening of the canal after root canal preparation. Results from the 2 groups were statistically compared using the Minitab statistical package. ProTaper rotary files left less untouched root canal surface compared with manual preparation in coronal, middle, and apical sector (p<0.001). Similarly, there was a statistically significant difference in root canal straightening after preparation between the techniques (p<0.001). Neither manual nor rotary techniques completely prepared the root canal, and both techniques caused slight straightening of the root canal.

  11. Radiographic, microcomputer tomography, and optical coherence tomography investigations of ceramic interfaces

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Ionita, Ciprian; Topala, Florin; Petrescu, Emanuela; Rominu, Roxana; Pop, Daniela Maria; Marsavina, Liviu; Negru, Radu; Bradu, Adrian; Rominu, Mihai; Podoleanu, Adrian Gh.

    2010-12-01

    Imagistic investigation of the metal-ceramic crowns and fixed partial prostheses represent a very important issue in nowadays dentistry. At this time, in dental office, it is difficult or even impossible to evaluate a metal ceramic crown or bridge before setting it in the oral cavity. The possibilities of ceramic fractures are due to small fracture lines or material defects inside the esthetic layers. Material and methods: In this study 25 metal ceramic crowns and fixed partial prostheses were investigated by radiographic method (Rx), micro computer tomography (MicroCT) and optical coherence tomography (OCT) working in Time Domain, at 1300 nm. The OCT system contains two interferometers and one scanner. For each incident analysis a stuck made of 100 slices was obtain. These slices were used in order to obtain a 3D model of the ceramic interface. Results: RX and MicroCT are very powerful instruments that provide a good characterization of the dental construct. It is important to observe the reflections due to the metal infrastructure that could affect the evaluation of the metal ceramic crowns and bridges. The OCT investigations could complete the imagistic evaluation of the dental construct by offering important information when it is need it.

  12. Rotary shear experiments under X-ray micro-computed tomography.

    PubMed

    Zhao, Qi; Tisato, Nicola; Grasselli, Giovanni

    2017-01-01

    A rotary shear apparatus (ERDμ-T) was designed, assembled, and calibrated to study frictional behavior. We paired the apparatus with X-ray micro-computed tomography (μCT) to inspect in situ and in operando deformation of the tested specimen. This technology allows us to observe how two rough surfaces interact and deform without perturbing the experimental conditions (e.g., pressure, temperature, and sample position). We performed an experiment employing an aluminum alloy sample to demonstrate the capability of the apparatus. The sample was sheared at incremental steps, and during shearing, normal force, sample shortening, torque, and shearing velocity were measured. The measurements were associated to the μCT imagery, giving a comprehensive understanding of the deformation processes of the samples. The present contribution demonstrates that the ERDμ-T allows (1) linking the variation of physical parameters to the evolution of internal structures of the sample and (2) shedding light on fracturing and frictional sliding processes in solid materials.

  13. Measurement of kidney stone formation in the rat model using micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Umoh, Joseph U.; Pitelka, Vasek; Goldberg, Harvey A.; Holdsworth, David W.

    2012-03-01

    Kidney stones were induced in 5 rats by treating them with 1% ethylene glycol and 1% ammonium chloride through free drinking water for six weeks. The animals were anesthetized and imaged in vivo before the treatment at week 0, to obtain baseline data, then at weeks 2 and 6 to monitor the kidney stone formation. Micro-CT imaging was performed with x-ray tube voltage of 90 kV and a current of 40 mA. At week 2, kidney stone formation was observed. A micro-computed tomography methodology of estimating the volume and hydroxyapatite-equivalent mineral content of the kidney stone is presented. It determines the threshold CT number (390 HU) that separates the kidney stone from the tissue. The mean volume of the stones in the 10 kidneys significantly increased from 3.81+/-0.72 mm3 at week 2 to 23.96+/-9.12 mm3 at week 6 (p<0.05, r2=0.34). Measurement precision error was about 4%. This method allows analysis of the kidney stone formation to be carried out in vivo, with fewer experimental animals compared with other ex vivo methods, in which animals are sacrificed. It is precise, accurate, non-destructive, and could be used in pre-clinical research to study the formation of kidney stones in live small animals.

  14. Three-dimensional microstructure of human alveolar trabecular bone: a micro-computed tomography study

    PubMed Central

    2017-01-01

    Purpose The microstructural characteristics of trabecular bone were identified using micro-computed tomography (micro-CT), in order to develop a potential strategy for implant surface improvement to facilitate osseointegration. Methods Alveolar bone specimens from the cadavers of 30 humans were scanned by high-resolution micro-CT and reconstructed. Volumes of interest chosen within the jaw were classified according to Hounsfield units into 4 bone quality categories. Several structural parameters were measured and statistically analyzed. Results Alveolar bone specimens with D1 bone quality had significantly higher values for all structural parameters than the other bone quality categories, except for trabecular thickness (Tb.Th). The percentage of bone volume, trabecular separation (Tb.Sp), and trabecular number (Tb.N) varied significantly among bone quality categories. Tb.Sp varied markedly across the bone quality categories (D1: 0.59±0.22 mm, D4: 1.20±0.48 mm), whereas Tb.Th had similar values (D1: 0.30±0.08 mm, D4: 0.22±0.05 mm). Conclusions Bone quality depended on Tb.Sp and number—that is, endosteal space architecture—rather than bone surface and Tb.Th. Regardless of bone quality, Tb.Th showed little variation. These factors should be taken into account when developing individualized implant surface topographies. PMID:28261521

  15. Micro-computed tomography characterization of tissue engineering scaffolds: effects of pixel size and rotation step.

    PubMed

    Cengiz, Ibrahim Fatih; Oliveira, Joaquim Miguel; Reis, Rui L

    2017-08-01

    Quantitative assessment of micro-structure of materials is of key importance in many fields including tissue engineering, biology, and dentistry. Micro-computed tomography (µ-CT) is an intensively used non-destructive technique. However, the acquisition parameters such as pixel size and rotation step may have significant effects on the obtained results. In this study, a set of tissue engineering scaffolds including examples of natural and synthetic polymers, and ceramics were analyzed. We comprehensively compared the quantitative results of µ-CT characterization using 15 acquisition scenarios that differ in the combination of the pixel size and rotation step. The results showed that the acquisition parameters could statistically significantly affect the quantified mean porosity, mean pore size, and mean wall thickness of the scaffolds. The effects are also practically important since the differences can be as high as 24% regarding the mean porosity in average, and 19.5 h and 166 GB regarding the characterization time and data storage per sample with a relatively small volume. This study showed in a quantitative manner the effects of such a wide range of acquisition scenarios on the final data, as well as the characterization time and data storage per sample. Herein, a clear picture of the effects of the pixel size and rotation step on the results is provided which can notably be useful to refine the practice of µ-CT characterization of scaffolds and economize the related resources.

  16. A New Method for Respiratory Gating During Microcomputed Tomography of Lung in Mice

    PubMed Central

    Johnson, Evan M; Price, Roger E; Kurie, Jonathan M; Rivera, Belinda S; Cody, Dianna D

    2008-01-01

    This study investigated the use of regulated cyclic breath-holds to improve microcomputed tomography (μCT) imaging of small (diameter, less than 1 mm) mouse lung tumors in vivo. Two novel techniques that use a modified small-animal ventilator were examined and compared with a previously used respiratory gating μCT technique and a free-breathing μCT technique. Two mice were scanned with each of these 4 μCT techniques (voxel size, 92 μm). The appearance of small lung tumors (maximal diameter, 0.5 to 1.0 mm) and the characteristics of line profiles of the lung–diaphragm boundary were used to compare the images obtained from the 4 acquisition techniques. The use of cyclic breath-holds, synchronized with the CT exposures, led to marked improvement in the visualization of the mouse lung structure and lesion conspicuity. A secondary experiment was performed to assess the stress placed on mice by the acquisition techniques. PMID:18702451

  17. Shrinkage assessment of low shrinkage composites using micro-computed tomography.

    PubMed

    Hirata, Ronaldo; Clozza, Emanuele; Giannini, Marcelo; Farrokhmanesh, Ehsan; Janal, Malvin; Tovar, Nick; Bonfante, Estevam A; Coelho, Paulo G

    2015-05-01

    The aim of this study was to quantify the polymerization volumetric shrinkage of one regular and two low shrinkage bulk fill composites in class I cavities with or without an adhesive layer, using three-dimensional (3D) micro-computed tomography (μCT). Class I cavity preparations (2.5 mm depth × 4 mm length × 4 mm wide) were standardized in 36 extracted human third molars, which were randomly divided in six groups (n = 6 each) as follows: Group VIT (regular composite without bonding agent); Group SDR (low shrinkage flowable composite without bonding agent); Group TET (low shrinkage composite without bonding agent); Group VIT/P (regular composite with bonding agent); Group SDR/X (low shrinkage flowable composite with bonding agent); TET/T (low shrinkage composite with bonding agent). Each tooth was scanned via µCT at cavity preparation, immediately after cavity filling, and after light-curing. Acquired μCT data were imported into Amira software for analysis and volume values evaluated between steps from cavity preparation until light-curing. Both low shrinkage composites showed a significantly less volumetric shrinkage than VIT. The use of dental adhesive significantly decreased the average volumetric contraction similarly for the three composites, by about 20%. Both low shrinkage composites showed less volumetric polymerization contraction than the regular composite. The use of dental adhesive decreased the total volumetric shrinkage for all evaluated composites. © 2014 Wiley Periodicals, Inc.

  18. Rotary shear experiments under X-ray micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Zhao, Qi; Tisato, Nicola; Grasselli, Giovanni

    2017-01-01

    A rotary shear apparatus (ERDμ-T) was designed, assembled, and calibrated to study frictional behavior. We paired the apparatus with X-ray micro-computed tomography (μCT) to inspect in situ and in operando deformation of the tested specimen. This technology allows us to observe how two rough surfaces interact and deform without perturbing the experimental conditions (e.g., pressure, temperature, and sample position). We performed an experiment employing an aluminum alloy sample to demonstrate the capability of the apparatus. The sample was sheared at incremental steps, and during shearing, normal force, sample shortening, torque, and shearing velocity were measured. The measurements were associated to the μCT imagery, giving a comprehensive understanding of the deformation processes of the samples. The present contribution demonstrates that the ERDμ-T allows (1) linking the variation of physical parameters to the evolution of internal structures of the sample and (2) shedding light on fracturing and frictional sliding processes in solid materials.

  19. Novel approach for quantification of porosity for biomaterial implants using microcomputed tomography (microCT).

    PubMed

    Hiu-Yan, Yeung; Ling, Qin; Kwong-Man, Lee; Ming, Zhang; Kwok-Sui, Leung; Chun-yiu, Cheng Jack

    2005-11-01

    Porous bioceramics have been widely investigated in orthopaedic tissue engineering. Attention has been given to manufacturing of a porous bioceramic that mimics the trabecular bone structure for proper bone regeneration. With the advance of biomedical imaging through microcomputed tomography (microCT), this study attempted to quantify the pore structure of different bioceramics. Two bioceramic blocks (BSC and ChronOS) were synthesized by two methods. The specification claimed the porosity of the bioceramic ranged from 40% to 70%. Six blocks of each bioceramic were evaluated by conventional water immersion method and microCT. The pore size and connectivity were evaluated with standardized protocols. By the water immersion method, the porosity of BSC and ChronOS was 60.4% and 74.7%, respectively. The three-dimensional results of microCT showed that BSC porosity was 26.2% and ChronOS was 60.0%. The pore connectivity was evaluated to be 2.6 for BSC and 39.7 for ChronOS. ChronOS had functional pores with 200 microm to 400 microm in diameter (87.8%+/-0.5%), which is significantly more than 52.8%+/-11.5% of pores in BSC (p<0.05). Providing information on the functional pores objectively, the microCT evaluation serves as a good standard for specification of the bioceramic-related implants. Copyright (c) 2005 Wiley Periodicals, Inc.

  20. Effects of preparation techniques on root canal shaping assessed by micro-computed tomography

    PubMed Central

    Stavileci, Miranda; Hoxha, Veton; Görduysus, Ömer; Tatar, Ilkan; Laperre, Kjell; Hostens, Jeroen; Küçükkaya, Selen; Berisha, Merita

    2013-01-01

    Background Root canal shaping without any procedural error is of the utmost preference. Therefore, the purpose of this study was to use micro-computed tomography to evaluate and compare the root canal shaping efficacy of ProTaper rotary files and standard stainless steel K-files. Material/Methods Sixty extracted upper second premolars were selected and were divided into 2 groups of 30. Before preparation, all samples were scanned by micro-CT. Then, 30 teeth were prepared with stainless steel files and the remaining 30 with ProTaper rotary files. Canal transportation and centering ability before and after root canal shaping were assessed using micro-CT. The amount and direction of canal transportation and the centering ratio of each instrument were determined in the coronal, middle, and apical parts of the canal. The 2 groups were statistically compared using one-way ANOVA. Results ProTaper rotary files gave less transportation (p<0.001) and better centering ability (p<0.00001) compared with stainless steel files. Conclusions The manual technique for preparation of root canals with stainless steel files produces more canal transportation, whereas rotary files remain more centered in the canal. PMID:23760162

  1. Three-dimensional imaging using microcomputed tomography for studying tooth macromorphology.

    PubMed

    Plotino, Gianluca; Grande, Nicola M; Pecci, Raffaella; Bedini, Rossella; Pameijer, Cornelis H; Somma, Francesco

    2006-11-01

    The authors conducted a study to demonstrate potential applications of microcomputed tomography (microCT) in the analysis of tooth morphology. The authors selected for microCT analysis five maxillary first molars with a second canal in the mesiobuccal (MB) root, five mandibular first molars with a mesial root possessing a considerable curvature and five single-canal premolars with complicated apical anatomy. The hardware device used in this study was a desktop X-ray microfocus CT scanner (SkyScan 1072, SkyScan bvba, Aartselaar, Belgium). The authors obtained a three-dimensional image from each of the 15 teeth. In three cases, the MB canals coalesced into one canal, while in the other two molars the canals were separate. Four of the five mandibular molars exhibited a single canal in the mesial root, which had a broad, flat appearance in a mesiodistal dimension. In the premolar teeth, the canals were independent; however, the apical delta and ramifications of the root canals were obvious, yet intricate. MicroCT offers a reproducible technique for 3-D noninvasive assessment of root canal systems. While this technique is not suitable for clinical use, it can be applied to improve preclinical training and analysis of fundamental procedures in endodontic and restorative treatment.

  2. Ridge preservation surgery after single and multiple adjacent tooth extractions: a microcomputed tomography study in dogs.

    PubMed

    Al-Hamoudi, Nawwaf; Bissada, Nabil F; Al-Askar, Mansour H; Al-Hezaimi, Khalid A

    2015-01-01

    The aim of this study was to determine, before implant placement, the outcome of ridge preservation surgery after extractions of one or more adjacent teeth on the dimensions of the edentulous ridge. Nineteen extraction sites in four dogs were randomly divided into three groups: group 1 = single premolars (n = 7 sites); group 2 = two adjacent premolars (n = 6 sites); group 3 = three adjacent premolars (n = 6 sites). Extraction was followed by ridge preservation surgery using a combination of xenograft and collagen membrane after full-thickness flap reflection. All animals were sacrificed 4 months later, and each extraction site was sectioned in the sagittal plane so that alveolar bone measurements could be made in both the buccolingual and apicocoronal directions using microcomputed tomography. Mean buccolingual width of the ridges postsurgery was 4.80 ± 2.78 mm, 4.98 ± 2.65 mm, and 4.79 ± 2.79 mm in groups 1, 2, and 3, respectively. The mean vertical distance from the cementoenamel junction to the crest of the ridge was 1.94 ± 0.42 mm, 2.05 ± 0.48 mm, and 2.60 ± 0.67 mm in groups 1, 2, and 3, respectively. No statistically significant difference was seen between single and multiple extraction sites. Ridge preservation surgery results in a similar pattern of bone remodeling in the horizontal and vertical dimensions of the edentulous ridge after single and multiple adjacent tooth extractions.

  3. Investigation of hindwing folding in ladybird beetles by artificial elytron transplantation and microcomputed tomography

    PubMed Central

    Nomura, Shuhei; Yamamoto, Shuhei; Niiyama, Ryuma; Okabe, Yoji

    2017-01-01

    Ladybird beetles are high-mobility insects and explore broad areas by switching between walking and flying. Their excellent wing transformation systems enabling this lifestyle are expected to provide large potential for engineering applications. However, the mechanism behind the folding of their hindwings remains unclear. The reason is that ladybird beetles close the elytra ahead of wing folding, preventing the observation of detailed processes occurring under the elytra. In the present study, artificial transparent elytra were transplanted on living ladybird beetles, thereby enabling us to observe the detailed wing-folding processes. The result revealed that in addition to the abdominal movements mentioned in previous studies, the edge and ventral surface of the elytra, as well as characteristic shaped veins, play important roles in wing folding. The structures of the wing frames enabling this folding process and detailed 3D shape of the hindwing were investigated using microcomputed tomography. The results showed that the tape spring-like elastic frame plays an important role in the wing transformation mechanism. Compared with other beetles, hindwings in ladybird beetles are characterized by two seemingly incompatible properties: (i) the wing rigidity with relatively thick veins and (ii) the compactness in stored shapes with complex crease patterns. The detailed wing-folding process revealed in this study is expected to facilitate understanding of the naturally optimized system in this excellent deployable structure. PMID:28507159

  4. Quantitative Micro-Computed Tomography Imaging of Vascular Dysfunction in Progressive Kidney Diseases.

    PubMed

    Ehling, Josef; Bábíčková, Janka; Gremse, Felix; Klinkhammer, Barbara M; Baetke, Sarah; Knuechel, Ruth; Kiessling, Fabian; Floege, Jürgen; Lammers, Twan; Boor, Peter

    2016-02-01

    Progressive kidney diseases and renal fibrosis are associated with endothelial injury and capillary rarefaction. However, our understanding of these processes has been hampered by the lack of tools enabling the quantitative and noninvasive monitoring of vessel functionality. Here, we used micro-computed tomography (µCT) for anatomical and functional imaging of vascular alterations in three murine models with distinct mechanisms of progressive kidney injury: ischemia-reperfusion (I/R, days 1-56), unilateral ureteral obstruction (UUO, days 1-10), and Alport mice (6-8 weeks old). Contrast-enhanced in vivo µCT enabled robust, noninvasive, and longitudinal monitoring of vessel functionality and revealed a progressive decline of the renal relative blood volume in all models. This reduction ranged from -20% in early disease stages to -61% in late disease stages and preceded fibrosis. Upon Microfil perfusion, high-resolution ex vivo µCT allowed quantitative analyses of three-dimensional vascular networks in all three models. These analyses revealed significant and previously unrecognized alterations of preglomerular arteries: a reduction in vessel diameter, a prominent reduction in vessel branching, and increased vessel tortuosity. In summary, using µCT methodology, we revealed insights into macro-to-microvascular alterations in progressive renal disease and provide a platform that may serve as the basis to evaluate vascular therapeutics in renal disease.

  5. A dataset comprising four micro-computed tomography scans of freshly fixed and museum earthworm specimens

    PubMed Central

    2014-01-01

    Background Although molecular tools are increasingly employed to decipher invertebrate systematics, earthworm (Annelida: Clitellata: ‘Oligochaeta’) taxonomy is still largely based on conventional dissection, resulting in data that are mostly unsuitable for dissemination through online databases. In order to evaluate if micro-computed tomography (μCT) in combination with soft tissue staining techniques could be used to expand the existing set of tools available for studying internal and external structures of earthworms, μCT scans of freshly fixed and museum specimens were gathered. Findings Scout images revealed full penetration of tissues by the staining agent. The attained isotropic voxel resolutions permit identification of internal and external structures conventionally used in earthworm taxonomy. The μCT projection and reconstruction images have been deposited in the online data repository GigaDB and are publicly available for download. Conclusions The dataset presented here shows that earthworms constitute suitable candidates for μCT scanning in combination with soft tissue staining. Not only are the data comparable to results derived from traditional dissection techniques, but due to their digital nature the data also permit computer-based interactive exploration of earthworm morphology and anatomy. The approach pursued here can be applied to freshly fixed as well as museum specimens, which is of particular importance when considering the use of rare or valuable material. Finally, a number of aspects related to the deposition of digital morphological data are briefly discussed. PMID:24839546

  6. Coronary wall imaging in mice using osmium tetroxide and micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Kozlowski, Megan; Donohue, Danielle; Chen, Marcus; Daniels, Mathew; Connelly, Patricia; Jeffries, Kenneth; Clevenger, Randall; Wen, Han H.; Pai, Vinay M.

    2011-07-01

    Coronary artery disease (CAD) is a major cause of death in the United States and results from the accumulation of atherosclerotic plaques in the arteries of the heart. Plaques accumulate as the result of the retention of low-density lipoprotein (LDL) particles in the sub-endothelium of the arterial wall. In mouse aorta, these lesions form primarily at the branching sites or bifurcations. However, in the coronary system, data has shown that late-stage plaque formation occurs throughout the proximal segments of the arteries. In order to better understand plaque formation in the coronary arteries, we have developed an osmium tetroxide (OsO4) stained coronary wall imaging protocol performed using microcomputed tomography (microCT). OsO4 is a heavy metal contrast agent that readily binds to lipids. Our data in 3- to 25-week old C57BL6 wild-type mice shows that the coronary vessel walls are highlighted by the use of the contrast agent. We expect that this combination of OsO4 and microCT will allow us to investigate the coronary artery wall in atherogenesis models of mice to characterize plaque formation.

  7. The use of microcomputed tomography to study microvasculature in small rodents.

    PubMed

    Bentley, Michael D; Ortiz, Maria C; Ritman, Erik L; Romero, J Carlos

    2002-05-01

    Appropriate nephron function is dependent on the intrarenal arrangement of blood vessels. The preferred and primary means to study the architecture of intrarenal circulation has been by filling it with opaque substances such as india ink, radio-opaque contrast material, or various polymers for study by light or scanning electron microscopy. With such methodologies, superficial vessels may obscure deep vessels and little quantitative information may be obtained. Serial-section microtomy has not been practical because of problems relating to alignment and registration of adjacent sections, lost sections, and preparation time and effort. Microcomputed tomography (micro-CT) overcomes such limitations and provides a means to study the three-dimensional architecture of filled vessels within an intact rodent kidney and to obtain more quantitative information. As an example of micro-CT's capabilities, we review the use of micro-CT to study the alterations in renal microvasculature caused by the development of liver cirrhosis after chronic bile duct ligation. In this example, micro-CT evidence shows a selective decrease in cortical vascular filling in the kidney, with a maintenance of medullary vascular filling. These changes may contribute to the salt and water retention that accompanies cirrhosis. These results indicate that micro-CT is a promising method to evaluate renal vascular architecture in the intact rodent kidney relative to physiological and pathological function.

  8. Volume measurement of crowns in mandibular primary central incisors by micro-computed tomography.

    PubMed

    Ma, Jin-Lan; Shi, Si-Zhen; Ide, Y; Saka, H; Matsunaga, S; Agematsu, H

    2013-09-01

    To determine sex differences in the tissue proportions of crowns of mandibular primary central incisors in Chinese children and to quantify the volume of crown components in three dimensions using micro-computed tomography (micro-CT). The specimens used in this study were 41 mandibular first deciduous incisor teeth with intact crowns (21 males and 20 females) obtained from patients between 5-6 years of age. Each specimen was scanned using micro-CT at a resolution of 0.05 mm and 3D-rendered images were created. The volume of each component of the crown was measured and examined for differences in different sex and ages. The pulp chamber volume decreased with age and the volume ratio of the pulp chamber to the whole crown was significantly smaller in 6-year-olds than in 5-year-olds (p < 0.05). Males had significantly larger tooth crown volumes and dentin volumes than females did (p < 0.001), while the volume of enamel showed no sexual dimorphism.

  9. Micro-computed tomography of false starts produced on bone by different hand-saws.

    PubMed

    Pelletti, Guido; Viel, Guido; Fais, Paolo; Viero, Alessia; Visentin, Sindi; Miotto, Diego; Montisci, Massimo; Cecchetto, Giovanni; Giraudo, Chiara

    2017-05-01

    The analysis of macro- and microscopic characteristics of saw marks on bones can provide useful information about the class of the tool utilized to produce the injury. The aim of the present study was to test micro-computed tomography (micro-CT) for the analysis of false starts experimentally produced on 32 human bone sections using 4 different hand-saws in order to verify the potential utility of micro-CT for distinguishing false starts produced by different saws and to correlate the morphology of the tool with that of the bone mark. Each sample was analysed through stereomicroscopy and micro-CT. Stereomicroscopic analysis allowed the identification of the false starts and the detection of the number of tool marks left by each saw. Micro-CT scans, through the integration of 3D renders and multiplanar reconstructions (MPR), allowed the identification of the shape of each false start correlating it to the injuring tool. Our results suggest that micro-CT could be a useful technique for assessing false starts produced by different classes of saws, providing accurate morphological profiles of the bone marks with all the advantages of high resolution 3D imaging (e.g., high accuracy, non-destructive analysis, preservation and documentation of evidence). However, further studies are necessary to integrate qualitative data with quantitative metrical analysis in order to further characterize the false start and the related injuring tool. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. Nondestructive Microcomputed Tomography Evaluation of Mineral Density in Exfoliated Teeth with Hypophosphatasia

    PubMed Central

    Hayashi, Takafumi; Sakamoto, Makoto; Sakai, Jun; Shimomura-Kuroki, Junko; Nishiyama, Hideyoshi; Katsura, Kouji; Ike, Makiko; Nikkuni, Yutaka; Nakayama, Miwa; Soga, Marie; Kobayashi, Taichi

    2016-01-01

    Most cases of hypophosphatasia (HPP) exhibit early loss of primary teeth. Results of microcomputed tomography (micro-CT) analysis of teeth with HPP have rarely been reported. The purpose of the present study was to describe the mineral density distribution and mapping of exfoliated teeth from an HPP patient using micro-CT. Four exfoliated teeth were obtained from a patient with HPP. Enamel and dentin mineral densities of exfoliated teeth were measured on micro-CT. The mean values of enamel and dentin mineral densities in mandibular primary central incisors with HPP were 1.61 and 0.98 g/cm3, respectively. The corresponding values in the mandibular primary lateral incisors were 1.60 and 0.98 g/cm3, respectively. Enamel hypoplasia was seen in the remaining teeth, both maxillary and mandibular primary canines and first and second molars. Micro-CT enables nondestructive, noninvasive evaluation and is useful for studying human hard tissues obtained from patients. PMID:27847653

  11. Effects of Articular Cartilage Constituents on Phosphotungstic Acid Enhanced Micro-Computed Tomography

    PubMed Central

    Karhula, Sakari S.; Finnilä, Mikko A.; Lammi, Mikko J.; Ylärinne, Janne H.; Kauppinen, Sami; Rieppo, Lassi; Pritzker, Kenneth P. H.; Nieminen, Heikki J.; Saarakkala, Simo

    2017-01-01

    Contrast-enhanced micro-computed tomography (CEμCT) with phosphotungstic acid (PTA) has shown potential for detecting collagen distribution of articular cartilage. However, the selectivity of the PTA staining to articular cartilage constituents remains to be elucidated. The aim of this study was to investigate the dependence of PTA for the collagen content in bovine articular cartilage. Adjacent bovine articular cartilage samples were treated with chondroitinase ABC and collagenase to degrade the proteoglycan and the collagen constituents in articular cartilage, respectively. Enzymatically degraded samples were compared to the untreated samples using CEμCT and reference methods, such as Fourier-transform infrared imaging. Decrease in the X-ray attenuation of PTA in articular cartilage and collagen content was observed in cartilage depth of 0–13% and deeper in tissue after collagen degradation. Increase in the X-ray attenuation of PTA was observed in the cartilage depth of 13–39% after proteoglycan degradation. The X-ray attenuation of PTA-labelled articular cartilage in CEμCT is associated mainly with collagen content but the proteoglycans have a minor effect on the X-ray attenuation of the PTA-labelled articular cartilage. In conclusion, the PTA labeling provides a feasible CEμCT method for 3D characterization of articular cartilage. PMID:28135331

  12. Quantification of arthritic bone degradation by analysis of 3D micro-computed tomography data

    PubMed Central

    Svensson, Carl-Magnus; Hoffmann, Bianca; Irmler, Ingo M.; Straßburger, Maria; Figge, Marc Thilo; Saluz, Hans Peter

    2017-01-01

    The use of animal models of arthritis is a key component in the evaluation of therapeutic strategies against the human disease rheumatoid arthritis (RA). Here we present quantitative measurements of bone degradation characterised by the cortical bone profile using glucose-6-phosphate isomerase (G6PI) induced arthritis. We applied micro-computed tomography (μCT) during three arthritis experiments and one control experiment to image the metatarsals of the hind paws and to investigate the effect of experimental arthritis on their cortical bone profile. For measurements of the cortical profile we automatically identified slices that are orthogonal to individual metatarsals, thereby making the measurements independent of animal placement in the scanner. We measured the average cortical thickness index (CTI) of the metatarsals, as well as the thickness changes along the metatarsal. In this study we introduced the cortical thickness gradient (CTG) as a new measure and we investigated how arthritis affects this measure. We found that in general both CTI and CTG are able to quantify arthritic progression, whilst CTG was found to be the more sensitive measure. PMID:28290525

  13. Application of microcomputed tomography for quantitative analysis of dental root canal obturations.

    PubMed

    Kierklo, Anna; Tabor, Zbisław; Petryniak, Rafał; Dohnalik, Marek; Jaworska, Małgorzata

    2014-03-24

    The aim of the study was to apply microcomputed tomography to quantitative evaluation of voids and to test any specific location of voids in tooth's root canal obturations. Twenty root canals were prepared and obturated with gutta-percha and Tubli-Seal sealer using the thermoplastic compaction method (System B+Obtura II). Roots were scanned and three-dimensional visualization was obtained. The volume and Feret's diameter of I-voids (at the filling/dentine interface) and S-voids (surrounded by filling material) were measured. The results revealed that none of the scanned root canal fillings were void-free. For I-voids, the volume fraction was significantly larger, but their number was lower (P=0.0007), than for S-voids. Both types of voids occurred in characteristic regions (P<0.001). I-voids occurred mainly in the apical third, while S-voids in the coronal third of the canal filling. Within the limitations of this study, our results indicate that microtomography, with proposed semi-automatic algorithm, is a useful tools for three-dimensional quantitative evaluation of dental root canal fillings. In canals filled with thermoplastic gutta-percha and Tubli-Seal, voids at the interface between the filling and canal dentine deserve special attention due to of their periapical location, which might promote apical microleakage. Further studies might help to elucidate the clinical relevance of these results.

  14. Micro-computed tomography image-based evaluation of 3D anisotropy degree of polymer scaffolds.

    PubMed

    Pérez-Ramírez, Ursula; López-Orive, Jesús Javier; Arana, Estanislao; Salmerón-Sánchez, Manuel; Moratal, David

    2015-01-01

    Anisotropy is one of the most meaningful determinants of biomechanical behaviour. This study employs micro-computed tomography (μCT) and image techniques for analysing the anisotropy of regenerative medicine polymer scaffolds. For this purpose, three three-dimensional anisotropy evaluation image methods were used: ellipsoid of inertia (EI), mean intercept length (MIL) and tensor scale (t-scale). These were applied to three patterns (a sphere, a cube and a right prism) and to two polymer scaffold topologies (cylindrical orthogonal pore mesh and spherical pores). For the patterns, the three methods provided good results. Regarding the scaffolds, EI mistook both topologies (0.0158, [-0.5683; 0.6001]; mean difference and 95% confidence interval), and MIL showed no significant differences (0.3509, [0.0656; 0.6362]). T-scale is the preferable method because it gave the best capability (0.3441, [0.1779; 0.5102]) to differentiate both topologies. This methodology results in the development of non-destructive tools to engineer biomimetic scaffolds, incorporating anisotropy as a fundamental property to be mimicked from the original tissue and permitting its assessment by means of μCT image analysis.

  15. Geometric analysis of porous bone substitutes using micro-computed tomography and fuzzy distance transform.

    PubMed

    Bashoor-Zadeh, M; Baroud, G; Bohner, M

    2010-03-01

    There is increased interest in resorbable bone substitutes for skeletal reconstruction. Important geometric design measures of bone substitute include pore size, interconnection size, porosity, permeability and surface area of the substitute. In this study, four substitute groups with variable geometric features but constant porosity were scanned using micro-computed tomography (microCT) and their geometric measures were determined using an advanced image-processing algorithm based on fuzzy distance transform and new pore size definition. The substitutes were produced using the calcium phosphate emulsion method. The geometric analysis revealed that the reproducibility of the emulsion method was high, within 5%. The average porosity of the four groups was 52.3 + or - 1.5. The pore diameter of the four bone substitute groups was measured to be 170 + or - 1.7, 217 + or - 5.2, 416 + or - 19, and 972 + or - 11 microm. Despite this significant change in pore size, the interconnection size only increased slightly with an increase of pore size. The specific surface decreased with increasing pore size. The permeability increased with the pore size and was inversely proportional to the specific surface. The combination of microCT and the fuzzy image-processing tool enables accurate geometric analysis, even if pore size and image resolution are in the same range, such as in the case of the smallest pore size. Moreover, it is an exciting tool to understand the structure of the substitute with the hope of designing better bone substitutes.

  16. Three-Dimensional Characterization of Cell Clusters Using Synchrotron-Radiation-Based Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Müller, Ert; Riedel, Marco; Thurner, Philipp J.

    2006-04-01

    Micro-computed tomography with the highly intense, monochromatic X rays produced by the synchrotron is a superior method to nondestructively measure the local absorption in three-dimensional space. Because biological tissues and cells consist mainly of water as the surrounding medium, higher absorbing agents have to be incorporated into the structures of interest. Even without X-ray optics such as refractive lens, one can uncover the stain distribution with the spatial resolution of about 1 [mu]m. Incorporating the stain at selected cell compartments, for example, binding to the RNA/DNA, their density distribution becomes quantified. In this communication, we demonstrate that tomograms obtained at the beamlines BW2 and W2 (HASYLAB at DESY, Hamburg, Germany) and 4S (SLS, Villigen, Switzerland) clearly show that the RNA/DNA-stained HEK 293 cell clusters have a core of high density and a peripheral part of lower density, which correlate with results of optical microscopy. The inner part of the clusters is associated with nonvital cells as the result of insufficient oxygen and nutrition supply. This necrotic part is surrounded by (6 ± 1) layers of vital cells.

  17. Surface area analysis of dental implants using micro-computed tomography.

    PubMed

    Schicho, Kurt; Kastner, Johann; Klingesberger, Roman; Seemann, Rudolf; Enislidis, Georg; Undt, Gerhard; Wanschitz, Felix; Figl, Michael; Wagner, Arne; Ewers, Rolf

    2007-08-01

    In this study, we present and evaluate a micro-computed tomography (micro-CT)-based method for the calculation of the potential bone/implant contact area (p-BICA) on the surface of dental implants. For seven commercially available implants (Ankylos implant, Brånemark System, Frialit CELLplus, Replace((R)) Select Tapered, Straumann Solid screw, XiVE S CELLplus, 3i Osseotite XP Threaded Miniplant, the p-BICA surface is determined by means of three-dimensional X-ray computed-tomography and computer-based data processing. Measurements were repeated two times, and the stability and repeatability of the measurement method were evaluated. Our analysis revealed a p-BICA of 118 mm(2) for the XiVE S CELLplus implant, 134 mm(2) for the Ankylos, 136 mm(2) for the Frialit CELLplus, 138 mm(2) for the Brånemark System, 139 mm(2) for the Replace((R)), 159 mm(2) for the 3i Osseotite XP and 199 mm(2) for the Straumann Solid screw implant. The measurement method proved to be stable and led to reproducible results. The micro- and macrostructure of dental implants define the surface and the p-BICA. Precise determination of this parameter can be achieved by means of the micro-CT-based method as presented in this study. The value of p-BICA lies in the predictability of industrial design before preclinical and clinical testing. Based on this method, dental implant properties become comparable even if geometrical details are not disclosed by the manufacturer.

  18. Surface area and volume measurements of volcanic ash particles using micro-computed tomography (micro-CT): A comparison with scanning electron microscope (SEM) stereoscopic imaging and geometric considerations

    NASA Astrophysics Data System (ADS)

    Ersoy, Orkun; Şen, Erdal; Aydar, Erkan; Tatar, İlkan; Çelik, H. Hamdi

    2010-10-01

    Volcanic ash particles are important components of explosive eruptions, and their surface textures are the subject of intense research. Characterization of ash surfaces is crucial for understanding the physics of volcanic plumes, remote sensing measurements of ash and aerosols, interfacial processes, modelling transportation and deposition of tephra and characterizing eruptive styles. A number of different methods have been used over the years to arrive at surface area estimates. The more common methods include estimates based on geometric considerations (geometric surface area) and physisorption of gas molecules on the surface of interest (physical surface area). In this study, micro computed tomography (micro-CT), which is a non-destructive method providing three-dimensional data, enabled the measurement of surface area and volume of individual ash particles. Results were compared with the values obtained from SEM stereoscopic imaging and geometric considerations. Surface area estimates of micro-CT and SEM stereoscopic imaging are similar, with surface area/volume ratios (SA/V) of 0.0368 and 0.0467, respectively. Ash particle surface textures show a large deviation from that of simple geometric forms, and an approximation both to spheres and ellipsoids do not seem adequate for the representation of ash surface. SEM stereoscopic and/or micro-CT imaging are here suggested as good candidate techniques for the characterization of textures on macro-pore regions of ash particles.

  19. Surface area and volume measurements of volcanic ash particles using micro-computed tomography (micro-CT): A comparison with scanning electron microscope (SEM) stereoscopic imaging and Brunauer-Emmett-Teller (BET) model

    NASA Astrophysics Data System (ADS)

    Ersoy, Orkun; Şen, Erdal; Aydar, Erkan; Tatar, Ä.°Lkan; Ćelik, H. Hamdi

    2010-05-01

    Volcanic ash particles are important components of explosive eruptions and their surface texture is the subject of intense research. Characterization of ash surfaces is crucial for understanding the physics of the volcanic plumes, remote sensing measurements of ash and aerosols, interfacial processes, modelling transportation and deposition of tephra and characterizing eruptive styles. A number of different methods have been used over the years to arrive at surface area estimates. The more common methods include estimates based on the geometric considerations (geometric surface area) and the physisorption of gas molecules on the surface of interest (physical surface area). In this study, micro computed tomography (micro-CT), a non-destructive method providing three-dimensional data enabled the measurement of surface areas and volumes of individual ash particles. Specific surface area estimates for ash particles were also obtained using nitrogen as gas adsorbent and the BET (Brunauer-Emmett-Teller) model. Results were compared with the values obtained from SEM stereoscopic imaging and geometric considerations. Surface area estimates of micro-CT and SEM stereoscopic imaging overlaps with mean specific surface area results of 0.0167 and 0.0214 m2/g, respectively. However, ash particle surface textures present quite a deviation from that of their geometric forms and approximation to sphere and ellipsoid both seemed to be inadequate for representation of real ash surfaces. The higher surface area estimate (> 0.4 m2/g) obtained from the technique based on physical sorption of gases (BET model here) was attributed to its capability for surface areas associated even with angstrom-sized pores. SEM stereoscopic and/or micro-CT imaging were suggested for characterization of textures on macro-pore regions of ash particles.

  20. Evaluation of a new mid-scala cochlear implant electrode using microcomputed tomography.

    PubMed

    Frisch, Christopher D; Carlson, Matthew L; Lane, John I; Driscoll, Colin L W

    2015-12-01

    To investigate electrode position, depth of insertion, and electrode contact using an electrode array with a mid-scala design following round window (RW) and cochleostomy insertion. Eight fresh-frozen cadaveric bones were implanted; half via a RW approach and half through an anteroinferior cochleostomy using a styleted mid-scala electrode design. Microcomputed tomography was used to acquire oblique coronal and oblique axial reformations. Individual electrode positions along each array, insertional depth, and electrode contact were determined using National Institutes of Health Image J software. All electrodes were inserted without significant resistance. The average angular depth of insertion was 436.5° for the RW group and 422.7° for the cochleostomy group. All electrodes acquired a perimodiolar position in the proximal segment and a lateral wall position at the basal turn, regardless of approach. Electrodes distal to the basal turn demonstrated a variable location, with 78% mid scala. One cochleostomy array fractured through the interscalar partition (ISP), acquiring a scala vestibuli position. The odds ratio for either abutting the modiolus, ISP, lateral wall or floor, or fracturing through the ISP were 2.7 times more likely following a cochleostomy insertion (P = .032). The styleted mid-scala electrode design acquires a proximal perimodiolar position, a lateral wall location, as it traverses the basal turn, and most commonly a mid-scala position in the distal array. Interscalar excursion occurred in one of the cochleostomy insertions. Cochleostomy insertion is more likely to result in ultimate final electrode position adjacent to critical intracochlear structures. NA. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  1. Long-term macrobioerosion in the Mediterranean Sea assessed by micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Färber, Claudia; Titschack, Jürgen; Schönberg, Christine Hanna Lydia; Ehrig, Karsten; Boos, Karin; Baum, Daniel; Illerhaus, Bernhard; Asgaard, Ulla; Granville Bromley, Richard; Freiwald, André; Wisshak, Max

    2016-06-01

    Biological erosion is a key process for the recycling of carbonate and the formation of calcareous sediments in the oceans. Experimental studies showed that bioerosion is subject to distinct temporal variability, but previous long-term studies were restricted to tropical waters. Here, we present results from a 14-year bioerosion experiment that was carried out along the rocky limestone coast of the island of Rhodes, Greece, in the Eastern Mediterranean Sea, in order to monitor the pace at which bioerosion affects carbonate substrate and the sequence of colonisation by bioeroding organisms. Internal macrobioerosion was visualised and quantified by micro-computed tomography and computer-algorithm-based segmentation procedures. Analysis of internal macrobioerosion traces revealed a dominance of bioeroding sponges producing eight types of characteristic Entobia cavity networks, which were matched to five different clionaid sponges by spicule identification in extracted tissue. The morphology of the entobians strongly varied depending on the species of the producing sponge, its ontogenetic stage, available space, and competition by other bioeroders. An early community developed during the first 5 years of exposure with initially very low macrobioerosion rates and was followed by an intermediate stage when sponges formed large and more diverse entobians and bioerosion rates increased. After 14 years, 30 % of the block volumes were occupied by boring sponges, yielding maximum bioerosion rates of 900 g m-2 yr-1. A high spatial variability in macrobioerosion prohibited clear conclusions about the onset of macrobioerosion equilibrium conditions. This highlights the necessity of even longer experimental exposures and higher replication at various factor levels in order to better understand and quantify temporal patterns of macrobioerosion in marine carbonate environments.

  2. Longitudinal in vivo microcomputed tomography of mouse lungs: No evidence for radiotoxicity

    PubMed Central

    Vande Velde, Greetje; De Langhe, Ellen; Poelmans, Jennifer; Bruyndonckx, Peter; d'Agostino, Emiliano; Verbeken, Erik; Bogaerts, Ria; Himmelreich, Uwe

    2015-01-01

    Before microcomputed tomography (micro-CT) can be exploited to its full potential for longitudinal monitoring of transgenic and experimental mouse models of lung diseases, radiotoxic side effects such as inflammation or fibrosis must be considered. We evaluated dose and potential radiotoxicity to the lungs for long-term respiratory-gated high-resolution micro-CT protocols. Free-breathing C57Bl/6 mice underwent four different retrospectively respiratory gated micro-CT imaging schedules of repeated scans during 5 or 12 wk, followed by ex vivo micro-CT and detailed histological and biochemical assessment of lung damage. Radiation exposure, dose, and absorbed dose were determined by ionization chamber, thermoluminescent dosimeter measurements and Monte Carlo calculations. Despite the relatively large radiation dose delivered per micro-CT acquisition, mice did not show any signs of radiation-induced lung damage or fibrosis when scanned weekly during 5 and up to 12 wk. Doubling the scanning frequency and once tripling the radiation dose as to mimic the instant repetition of a failed scan also stayed without detectable toxicity after 5 wk of scanning. Histological analyses confirmed the absence of radiotoxic damage to the lungs, thereby demonstrating that long-term monitoring of mouse lungs using high-resolution micro-CT is safe. This opens perspectives for longitudinal monitoring of (transgenic) mouse models of lung diseases and therapeutic response on an individual basis with high spatial and temporal resolution, without concerns for radiation toxicity that could potentially influence the readout of micro-CT-derived lung biomarkers. This work further supports the introduction of micro-CT for routine use in the preclinical pulmonary research field where postmortem histological approaches are still the gold standard. PMID:26024893

  3. Attenuation Drift in the Micro-Computed Tomography System at LLNL

    SciTech Connect

    Dooraghi, Alex A.; Brown, William; Seetho, Isaac; Kallman, Jeff; Lennox, Kristin; Glascoe, Lee

    2016-01-12

    The maximum allowable level of drift in the linear attenuation coefficients (μ) for a Lawrence Livermore National Laboratory (LLNL) micro-computed tomography (MCT) system was determined to be 0.1%. After ~100 scans were acquired during the period of November 2014 to March 2015, the drift in μ for a set of six reference materials reached or exceeded 0.1%. Two strategies have been identified to account for or correct the drift. First, normalizing the 160 kV and 100 kV μ data by the μ of water at the corresponding energy, in contrast to conducting normalization at the 160 kV energy only, significantly compensates for measurement drift. Even after the modified normalization, μ of polytetrafluoroethylene (PTFE) increases linearly with scan number at an average rate of 0.00147% per scan. This is consistent with PTFE radiation damage documented in the literature. The second strategy suggested is the replacement of the PTFE reference with fluorinated ethylene propylene (FEP), which has the same effective atomic number (Ze) and electron density (ρe) as PTFE, but is 10 times more radiation resistant. This is important as effective atomic number and electron density are key parameters in analysis. The presence of a material with properties such as PTFE, when taken together with the remaining references, allows for a broad range of the (Ze, ρe) feature space to be used in analysis. While FEP is documented as 10 times more radiation resistant, testing will be necessary to assess how often, if necessary, FEP will need to be replaced. As radiation damage to references has been observed, it will be necessary to monitor all reference materials for radiation damage to ensure consistent x-ray characteristics of the references.

  4. Early Lung Adenocarcinoma in Mice: Micro-Computed Tomography Manifestations and Correlation with Pathology.

    PubMed

    Deng, Lin; Xiao, Shi Man; Qiang, Jin Wei; Li, Yong Ai; Zhang, Yu

    2017-06-01

    Lung cancer is the most common fatal malignancy for both men and women and adenocarcinoma is the most common histologic type. Early diagnosis of lung cancer can significantly improve the survival rate of patients. This study aimed to investigate the micro-computed tomography (micro-CT) manifestations of early lung adenocarcinoma (LAC) in mice and to provide a new perspective for early clinical diagnosis. Early LAC models in 10 mice were established by subcutaneously injecting 1-methyl-3-nitro-1-nitrosoguanidine (MNNG) solution. Micro-CT scan and multiple planar reconstruction (MPR) were used for mouse lungs. Micro-CT features of early LAC, especially the relationships between tumor and bronchus, were analyzed and correlated with pathology. Micro-CT findings of early LAC were divided into three types: non-solid (n = 8, 6%), partly solid (n = 85, 64%) and totally solid (n = 39, 30%). Tumor-bronchus relationships, which could be observed in 110 of 132(83%) LAC, were classified into four patterns: type I (n = 16, 15%), bronchus was truncated at the margin of the tumor; type II (n = 33, 30%), bronchus penetrated into the tumor with tapered narrowing and interruption; type III (n = 38, 35%), bronchus penetrated into the tumor with a patent and intact lumen; type IV (n = 99, 90%), bronchus ran at the border of the tumor with an intact or compressed lumen. Micro-CT manifestations of early LAC correlated well with pathological findings. Micro-CT can clearly demonstrate the features of mouse early LAC and bronchus-tumor relationships, and can also provide a new tool and perspective for the study of early LAC. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Three-dimensional observation of mouse tongue muscles using micro-computed tomography.

    PubMed

    Aoyagi, Hidekazu; Iwasaki, Shin-Ichi; Nakamura, Kenzirou

    2015-01-01

    The aim of this study is to obtain information about the mouse tongue muscle rendered using micro-computed tomography (μCT) at low, middle, and high magnifications. Three-dimensional (3D) μCT is used in various fields. Most μCT observations are restricted to hard tissue in biomaterial samples. Recently, with the use of osmium tetroxide, μCT has been effectively employed to observe soft tissue; it is now believed that μCT observation of soft tissue is feasible. On the other hand, the structure of the tongue muscle has been well studied, but cross-sectional imaging enhanced by 3D rendering is lacking. We chose the mouse tongue as a soft tissue case study for μCT and generated cross-sectional images of the tongue enhanced by 3-D image rendering with histological resolution. During this observation, we developed new methods of low-magnification observation to show the relation between the tongue muscles and surrounding tissues. We also applied high-resolution μCT in high-magnification observation of muscle fiber fascicles. Our methodological techniques give the following results: (1) For low-magnification observation (field of view: 12,000 μm), pretreatment with decalcification and freeze drying is suitable for observing the area between the muscle of the tongue and the bone around the tongue using μCT. (2) For middle-magnification observation (Field of view: 3,500 μm), the use of osmium tetroxide to observe the muscle arrangement of the tongue by μCT is suitable. (3) For high-magnification observation (Field of view: 450 μm), high-resolution μCT is suitable for observation of the transversus muscle fiber fascicles.

  6. Oval-shaped canal retreatment with self-adjusting file: a micro-computed tomography study.

    PubMed

    Keleş, Ali; Alcin, Hatice; Kamalak, Aliye; Versiani, Marco A

    2014-05-01

    The aim of this study was to assess the efficacy of removing the filling material from oval-shaped canals with rotary retreatment files, with or without the additional use of self-adjusting file (SAF), using micro-computed tomography. Oval-shaped canals from 20 maxillary premolars were prepared and assigned to two groups (n = 10), according to the obturation technique: cold lateral condensation (CLC) or vertical condensation (VC). Then, retreatment procedure was performed with retreatment rotary instruments followed by SAF. The specimens were scanned after each procedure and the volume of the filling material calculated. Median and interquartile range (IQR) percentages of the remaining filling material after each retreatment technique were statistically compared by Wilcoxon and Mann–Whitney U tests with a significance level of 5 %. The median percentage volume of the filling residue after rotary retreatment procedure was 1.59 (IQR = 1.26) and 0.42 (IQR = 0.86) in the CLC and VC groups, respectively (p < 0.05). After the use of SAF, the median percentage was 1.26 (IQR = 0.75) and 0.12 (IQR = 0.53) in the CLC and VC groups, respectively (p < 0.05). Statistically significant difference was also observed within the group after the additional use of SAF (p < 0.05). None of the retreatment procedures completely removed the filling material. The additional use of the SAF improved the removal of filling material after the retreatment procedure with rotary instruments. Filling material left after retreatment procedure may harbour necrotic tissue and bacteria, which could lead to a persistent disease and reinfection of the root canal system. The additional use of self-adjusting file after the conventional retreatment procedures may improve root canal cleanliness, allowing a better action of the irrigating solution.

  7. Morphometric analysis of the Korean mandibular ramus for distraction osteogenesis using micro-computed tomography.

    PubMed

    Lee, Jae-Gi; Kim, Il-Soo; Kim, Young-Woo; Park, Jong-Tae; Hu, Kyung-Seok; Kim, Hyung-Gon; Kim, Hee-Jin

    2011-01-01

    When performing distraction osteogenesis, the osteotomy is normally applied to the cortical bone posterior to the mandibular second molar. We measured the topographic thickness of the cortical and trabecular bone of the mandibular ramus and at the mandibular canal (MC) to provide crucial anatomic data aimed at minimizing complications and elucidating the most appropriate site for placing the distractor. Forty sides of the mandibles were prepared from 20 Korean cadavers (10 men and 10 women with a mean age of 68 years). The specimens were scanned and reconstructed into three-dimensional images using a micro-computed tomography system. Coronal and horizontal sectional images of the mandibular ramus were taken at thickness intervals of 2 mm from the reconstructed three-dimensional images. Image analysis software was used to measure the thicknesses of the cortical and trabecular bone and to identify the locations of the MC within the body and the mandibular ramus on each section. The mean thicknesses of the buccal cortical plate, trabecular bone, and lingual cortical plate were 2.9 mm (men, 3.0 mm; women, 2.8 mm), 9.1 mm (men, 9.8 mm; women, 8.5 mm), and 2.2 mm (men, 2.3 mm; women, 2.1 mm), respectively. The distance from the buccal surface of the mandible to the MC increased from 5.3 to 10.0 mm (men, 5.3-10.0 mm; women, 5.3-9.1 mm) when moving progressively anterosuperior from the mandibular angle region. Morphometric analyses of the mandibular ramus can provide crucial data when performing mandibular osteotomy and locating an appropriate placement site for a distractor device during the distraction-osteogenesis procedure.

  8. Quantitative three-dimensional analysis of embryonic chick morphogenesis via microcomputed tomography.

    PubMed

    Kim, Jun Sup; Min, Jouha; Recknagel, Andrew K; Riccio, Mark; Butcher, Jonathan T

    2011-01-01

    Embryonic development is a remarkably complex and rapidly evolving morphogenetic process. Although many of the early patterning events have been well described, understanding the anatomical changes at later stages where clinically relevant malformations are more likely to be survivable has been limited by the lack of quantitative 3D imaging tools. Microcomputed tomography (Micro-CT) has emerged as a powerful tool for embryonic imaging, but a quantitative analysis of organ and tissue growth has not been conducted. In this study, we present a simple method for acquiring highly detailed, quantitative 3D datasets of embryonic chicks with Micro-CT. Embryos between 4 and 12 days (HH23 and HH40) were labeled with osmium tetroxide (OT), which revealed highly detailed soft tissue anatomy when scanned at 25 μm resolution. We demonstrate tissue boundary and inter-tissue contrast fidelity in virtual 2D sections are quantitatively and qualitatively similar to those of histological sections. We then establish mathematical relationships for the volumetric growth of heart, limb, eye, and brain during this period of development. We show that some organs exhibit constant exponential growth (eye and heart), whereas others contained multiple phases of growth (forebrain and limb). Furthermore, we show that cardiac myocardial volumetric growth differs in a time and chamber specific manner. These results demonstrate Micro-CT is a powerful technique for quantitative imaging of embryonic growth. The data presented here establish baselines from which to compare the effects of genetic or experimental perturbations. Quantifying subtle differences in morphogenesis is increasingly important as research focuses on localized and conditional effects.

  9. In vitro quantification of wear in tibial inserts using microcomputed tomography.

    PubMed

    Teeter, Matthew G; Naudie, Douglas D R; McErlain, David D; Brandt, Jan-M; Yuan, Xunhua; Macdonald, Steven J; Holdsworth, David W

    2011-01-01

    Wear of polyethylene tibial inserts can decrease the longevity of total knee arthroplasty. Wear is currently assessed using laboratory methods that may not permit backside wear measurements or do not quantify surface deviation. We developed and validated a technique to quantify polyethylene wear in tibial inserts using microcomputed tomography (micro-CT), a nondestructive high-resolution imaging technique that provides detailed images of surface geometry in addition to volumetric measurements. Six unworn and six wear-simulated polyethylene tibial inserts were evaluated. Each insert was scanned three times using micro-CT at a resolution of 50 μm. The insert surface was reconstructed for each scan and the insert volume was calculated. Gravimetric analysis was performed for all inserts, and the micro-CT and gravimetric volumes were compared to determine accuracy. We created three-dimensional surface deviation maps. Micro-CT generated high-quality three-dimensional renderings of the insert surface geometry. Between-scan precision was 0.07%; we observed no difference between micro-CT and gravimetric volume measurements. Micro-CT can provide precise and accurate volumetric measurements in addition to quantifiable three-dimensional surface deviation maps for the entire insert surface. The technique has the potential to evaluate wear in wear simulator trials and retrieval studies. This micro-CT technique combines the benefits of volumetric and surface scanning methods to quantify wear across all surfaces of polyethylene components with a single tool. When applied in wear simulator and retrieval studies, these measurements can be used to evaluate and predict the wear properties of the components.

  10. Quantitative imaging of murine osteoarthritic cartilage by phase-contrast micro-computed tomography.

    PubMed

    Ruan, Merry Z C; Dawson, Brian; Jiang, Ming-Ming; Gannon, Francis; Heggeness, Michael; Lee, Brendan H L

    2013-02-01

    The mouse is an optimal model organism in which gene-environment interactions can be used to study the pathogenesis of osteoarthritis (OA). The gold standard for arthritis research in mice is based on histopathology and immunohistochemistry, which are labor-intensive, prone to sampling bias and technical variability, and limited in throughput. The aim of this study was to develop a new technique that assesses mouse cartilage by integrating quantitative volumetric imaging techniques. A novel mouse model of OA was generated by cruciate ligament transection (CLT) and evaluated by histopathology and immunohistochemistry. Knee joint specimens were then imaged using a new technique that combines high-resolution micro-computed tomography (micro-CT) and phase-contrast optics followed by quantitative analyses. A comparative analysis was also performed in a previously established mouse model of OA generated by destabilization of the medial meniscus (DMM). Phase-contrast micro-CT achieved cellular resolution of chondrocytes and quantitative assessment of parameters such as articular cartilage volume and surface area. In mouse models of OA generated by either CLT or DMM, we showed that phase-contrast micro-CT distinguished control and OA cartilage by providing quantitative measures with high reproducibility and minimal variability. Features of OA at the cellular or tissue level could also be observed in images generated by phase-contrast micro-CT. We established an imaging technology that comprehensively assessed and quantified the 2-dimensional and 3-dimensional changes of articular cartilage. Application of this technology will facilitate the rapid and high-throughput assessment of genetic and therapeutic models of OA in mice. Copyright © 2013 by the American College of Rheumatology.

  11. Micro-computed tomography evaluation of human fat grafts in nude mice.

    PubMed

    Chung, Michael T; Hyun, Jeong S; Lo, David D; Montoro, Daniel T; Hasegawa, Masakazu; Levi, Benjamin; Januszyk, Michael; Longaker, Michael T; Wan, Derrick C

    2013-03-01

    Although autologous fat grafting has revolutionized the field of soft tissue reconstruction and augmentation, long-term maintenance of fat grafts is unpredictable. Recent studies have reported survival rates of fat grafts to vary anywhere between 10% and 80% over time. The present study evaluated the long-term viability of human fat grafts in a murine model using a novel imaging technique allowing for in vivo volumetric analysis. Human fat grafts were prepared from lipoaspirate samples using the Coleman technique. Fat was injected subcutaneously into the scalp of 10 adult Crl:NU-Foxn1(nu) CD-1 male mice. Micro-computed tomography (CT) was performed immediately following injection and then weekly thereafter. Fat volume was rendered by reconstructing a three-dimensional (3D) surface through cubic-spline interpolation. Specimens were also harvested at various time points and sections were prepared and stained with hematoxylin and eosin (H&E), for macrophages using CD68 and for the cannabinoid receptor 1 (CB1). Finally, samples were explanted at 8- and 12-week time points to validate calculated micro-CT volumes. Weekly CT scanning demonstrated progressive volume loss over the time course. However, volumetric analysis at the 8- and 12-week time points stabilized, showing an average of 62.2% and 60.9% survival, respectively. Gross analysis showed the fat graft to be healthy and vascularized. H&E analysis and staining for CD68 showed minimal inflammatory reaction with viable adipocytes. Immunohistochemical staining with anti-human CB1 antibodies confirmed human origin of the adipocytes. Studies assessing the fate of autologous fat grafts in animals have focused on nonimaging modalities, including histological and biochemical analyses, which require euthanasia of the animals. In this study, we have demonstrated the ability to employ micro-CT for 3D reconstruction and volumetric analysis of human fat grafts in a mouse model. Importantly, this model provides a platform for

  12. Difference in Spinal Fusion Process in Osteopenic and Nonosteopenic Living Rat Models Using Serial Microcomputed Tomography.

    PubMed

    Park, Sung Bae; Yang, Hee-Jin; Kim, Chi Heon; Chung, Chun Kee

    2017-05-01

    To identify and investigate differences in spinal fusion between the normal and osteopenic spine in a rat model. Female Sprague Dawley rats underwent either an ovariectomy (OVX) or sham operation and were randomized into two groups: non-OVX group and OVX group. Eight weeks after OVX, unilateral lumbar spinal fusion was performed using autologous iliac bone. Bone density (BD) was measured 2 days and 8 weeks after fusion surgery. Microcomputed tomography was used to evaluate the process of bone fusion every two weeks for 8 weeks after fusion surgery. The fusion rate, fusion process, and bone volume parameters of fusion bed were compared between the two groups. BD was significantly higher in the non-OVX group than in the OVX group 2 days and 8 weeks after fusion surgery. The fusion rate in the non-OVX group was higher than that in the OVX group 8 weeks after surgery (p=0.044). The bony connection of bone fragments with transverse processes and bone formation between transverse processes in non-OVX group were significantly superior to those of OVX group from 6 weeks after fusion surgery. The compactness and bone maturation of fusion bed in non-OVX were prominent compared with the non-OVX group. The fusion rate in OVX group was inferior to non-OVX group at late stage after fusion surgery. Bone maturation of fusion bed in the OVX group was inferior compared with the non-OVX group. Fusion enhancement strategies at early stage may be needed to patients with osteoporosis who need spine fusion surgery.

  13. Optimizing a micro-computed tomography-based surrogate measurement of bone-implant contact.

    PubMed

    Meagher, Matthew J; Parwani, Rachna N; Virdi, Amarjit S; Sumner, Dale R

    2017-08-29

    Histology and backscatter scanning electron microscopy (bSEM) are the current gold standard methods for quantifying bone-implant contact (BIC), but are inherently destructive. Microcomputed tomography (μCT) is a non-destructive alternative, but attempts to validate μCT-based assessment of BIC in animal models have produced conflicting results. We previously showed in a rat model using a 1.5 mm diameter titanium implant that the extent of the metal-induced artefact precluded accurate measurement of bone sufficiently close to the interface to assess BIC. Recently introduced commercial laboratory μCT scanners have smaller voxels and improved imaging capabilities, possibly overcoming this limitation. The goals of the present study were to establish an approach for optimizing μCT imaging parameters and to validate μCT-based assessment of BIC. In an empirical parametric study using a 1.5 mm diameter titanium implant, we determined 90 kVp, 88 µA, 1.5 μm isotropic voxel size, 1600 projections/180°, and 750 ms integration time to be optimal. Using specimens from an in vivo rat experiment, we found significant correlations between bSEM and μCT for BIC with the manufacturer's automated analysis routine (r = 0.716, p = 0.003) or a line-intercept method (r = 0.797, p = 0.010). Thus, this newer generation scanner's improved imaging capability reduced the extent of the metal-induced artefact zone enough to permit assessment of BIC. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 9 999:XX-XX, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  14. Moisture content of root canal dentine affects detection of microcracks using micro-computed tomography.

    PubMed

    Rödig, T; Müller, C; Hoch, M; Haupt, F; Schulz, X; Wiegand, A; Rizk, M

    2017-08-30

    To evaluate the effect of moisture content in root canal dentine on detection of microcracks using micro-computed tomography. Ten roots with and without craze lines or cracks (each n = 5) were selected and scanned six times with different moisture conditions of root dentine using a micro-CT scanner at a high resolution of 10.5 μm. Scanning conditions were as follows: (i) after 30-day wet storage, (ii) after 2-h dry time, (iii) after 48-h wet storage, (iv) after 24-h dry time, (v) after 48-h wet storage, (vi) after 2-h dry time. From each scan, cross-sectional images were obtained at intervals of 1 mm (total n = 708) and evaluated for the presence of dentinal microcracks twice by five calibrated blinded observers. Statistical analysis was performed by nonparametric analysis of variance for longitudinal data (P < 0.05). Intra-rater percentage agreement ranged between 92% and 98%, whereas inter-rater percentage agreement was 81% and 83%, respectively. No significant differences between all wet groups as well as between both groups with 2-h dry time were detected (P > 0.05). Almost no cracks were observed after wet storage with a significant increase of cracks after 2-h dry time (P < 0.001). Significantly more microcracks were identified after 24 h than after 2-h dry time (P < 0.004). Moisture content of dentine influenced detection of microcracks when evaluated using micro-CT. Scanning should be performed on dried specimens to allow reliable identification of dentinal defects. Formation of new cracks during dry periods up to 24 h was disproved. © 2017 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  15. Stenotic Bicuspid and Tricuspid Aortic Valves - Micro-Computed Tomography and Biological Indices of Calcification.

    PubMed

    Mazur, Piotr; Wypasek, Ewa; Gawęda, Bogusław; Sobczyk, Dorota; Kapusta, Przemysław; Natorska, Joanna; Malinowski, Krzysztof Piotr; Tarasiuk, Jacek; Bochenek, Maciej; Wroński, Sebastian; Chmielewska, Katarzyna; Kapelak, Bogusław; Undas, Anetta

    2017-06-23

    Valve calcification is well estimated by ex-vivo micro-computed tomography (micro-CT). The objective of this study was to investigate the associations between micro-CT findings and biological indices of calcification in aortic stenosis (AS), as well as differences between bicuspid aortic valve (BAV) and tricuspid aortic valve (TAV).Methods and Results:Aortic valves and plasma were obtained from patients undergoing valve surgery. Valves were dissected and underwent micro-CT, genetic analyses, and calcium content assessment. Plasma levels of calcification markers were measured. Forty-two patients with isolated severe AS, including 22 with BAV, were studied. BAV patients had a lower median CT value (140.0 [130.0-152.0] vs. 157.0 [147.0-176.0], P=0.002) and high-density calcification (HDC) fraction (9.3 [5.7-23.3] % vs. 21.3 [14.3-31.2] %, P=0.01), as compared with TAV. Calcification fraction (CF) correlated with AS severity (measured as maximal transvalvular pressure gradient [r=0.34, P=0.03], maximal flow velocity [r=0.38, P=0.02], and indexed aortic valve area [r=-0.37, P=0.02]). For TAV patients only, mRNA expression of integrin-binding sialoprotein correlated with CF (r=0.45, P=0.048), and the receptor activator of the nuclear factor κ-B ligand transcript correlated with HDC corrugation (r=0.54, P=0.01). TAV patients with AS present more mineralized calcifications in micro-CT than BAV subjects. The relative volume of calcifications increases with the AS severity. In TAV patients, upregulated expression of genes involved in osteoblastogenesis in AS correlates with leaflet mineralization in micro-CT.

  16. Particle-induced osteolysis in three-dimensional micro-computed tomography.

    PubMed

    Wedemeyer, Christian; Xu, Jie; Neuerburg, Carl; Landgraeber, Stefan; Malyar, Nasser M; von Knoch, Fabian; Gosheger, Georg; von Knoch, Marius; Löer, Franz; Saxler, Guido

    2007-11-01

    Small-animal models are useful for the in vivo study of particle-induced osteolysis, the most frequent cause of aseptic loosening after total joint replacement. Microstructural changes associated with particle-induced osteolysis have been extensively explored using two-dimensional (2D) techniques. However, relatively little is known regarding the 3D dynamic microstructure of particle-induced osteolysis. Therefore, we tested micro-computed tomography (micro-CT) as a novel tool for 3D analysis of wear debris-mediated osteolysis in a small-animal model of particle-induced osteolysis. The murine calvarial model based on polyethylene particles was utilized in 14 C57BL/J6 mice randomly divided into two groups. Group 1 received sham surgery, and group 2 was treated with polyethylene particles. We performed 3D micro-CT analysis and histological assessment. Various bone morphometric parameters were assessed. Regression was used to examine the relation between the results achieved by the two methods. Micro-CT analysis provides a fully automated means to quantify bone destruction in a mouse model of particle-induced osteolysis. This method revealed that the osteolytic lesions in calvaria in the experimental group were affected irregularly compared to the rather even distribution of osteolysis in the control group. This is an observation which would have been missed if histomorphometric analysis only had been performed, leading to false assessment of the actual situation. These irregularities seen by micro-CT analysis provide new insight into individual bone changes which might otherwise be overlooked by histological analysis and can be used as baseline information on which future studies can be designed.

  17. Longitudinal in vivo microcomputed tomography of mouse lungs: No evidence for radiotoxicity.

    PubMed

    Vande Velde, Greetje; De Langhe, Ellen; Poelmans, Jennifer; Bruyndonckx, Peter; d'Agostino, Emiliano; Verbeken, Erik; Bogaerts, Ria; Lories, Rik; Himmelreich, Uwe

    2015-08-01

    Before microcomputed tomography (micro-CT) can be exploited to its full potential for longitudinal monitoring of transgenic and experimental mouse models of lung diseases, radiotoxic side effects such as inflammation or fibrosis must be considered. We evaluated dose and potential radiotoxicity to the lungs for long-term respiratory-gated high-resolution micro-CT protocols. Free-breathing C57Bl/6 mice underwent four different retrospectively respiratory gated micro-CT imaging schedules of repeated scans during 5 or 12 wk, followed by ex vivo micro-CT and detailed histological and biochemical assessment of lung damage. Radiation exposure, dose, and absorbed dose were determined by ionization chamber, thermoluminescent dosimeter measurements and Monte Carlo calculations. Despite the relatively large radiation dose delivered per micro-CT acquisition, mice did not show any signs of radiation-induced lung damage or fibrosis when scanned weekly during 5 and up to 12 wk. Doubling the scanning frequency and once tripling the radiation dose as to mimic the instant repetition of a failed scan also stayed without detectable toxicity after 5 wk of scanning. Histological analyses confirmed the absence of radiotoxic damage to the lungs, thereby demonstrating that long-term monitoring of mouse lungs using high-resolution micro-CT is safe. This opens perspectives for longitudinal monitoring of (transgenic) mouse models of lung diseases and therapeutic response on an individual basis with high spatial and temporal resolution, without concerns for radiation toxicity that could potentially influence the readout of micro-CT-derived lung biomarkers. This work further supports the introduction of micro-CT for routine use in the preclinical pulmonary research field where postmortem histological approaches are still the gold standard.

  18. Extraction and visualization of a fracture network using Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Rath, A.; Voorn, M.; Exner, U.

    2012-04-01

    Micro-Computed Tomography (µCT) measurements were conducted on 3 cm dolomite drill core plugs to gain knowledge about the distribution and orientation of a fracture network inside such plugs. µCT produces a 3D-image stack of 2D-images and these are used to reconstruct a 3D-Model of the fracture network representing the main pore space. The measurements are performed on a Rayscan 250 E at the University of Applied Sciences of Upper Austria (Fachhochschule Oberösterreich, FHÖO) using optimal recording parameters, to ensure the best spatial resolution and image quality. The resolution of the performed scans is around 20 µm. Each scan is acquired five times and then averaged to increase contrast and decrease noise artifacts. Due to the fact that the fracture apertures can be far below 20 µm, noise can be a main drawback to be able to segment the fractures. To decrease a further impact of noise we filter the images after image acquisition, by means of image histogram equalization and edge enhanced diffusion. Segmenting the fractures and the fracture network is not trivial. Many different segmentation routines the one option giving by far the best results was the Frangi Filter 2D. This filter was written in the medical research field to trace blood vessels. From a data perspective blood vessels are rather similar structures to fractures. However, the results are intensity images so that we still have to use a global threshold. This step is done by the automatic Otsu threshold, which is not biased by any human input. From a segmented image it is possible to quantify the apertures, orientation and distribution of the fractures. Using this technique can provide deep insight into the deformation history and a geometrical dataset to calculate permeability of a fracture network, which is additionally calibrated with conventional thin section analysis.

  19. Architecture of the rat nephron-arterial network: analysis with micro-computed tomography.

    PubMed

    Marsh, Donald J; Postnov, Dmitry D; Rowland, Douglas J; Wexler, Anthony S; Sosnovtseva, Olga V; Holstein-Rathlou, Niels-Henrik

    2017-08-01

    Among solid organs, the kidney's vascular network stands out, because each nephron has two distinct capillary structures in series and because tubuloglomerular feedback, one of the mechanisms responsible for blood flow autoregulation, is specific to renal tubules. Tubuloglomerular feedback and the myogenic mechanism, acting jointly, autoregulate single-nephron blood flow. Each generates a self-sustained periodic oscillation and an oscillating electrical signal that propagates upstream along arterioles. Similar electrical signals from other nephrons interact, allowing nephron synchronization. Experimental measurements show synchronization over fields of a few nephrons; simulations based on a simplified network structure that could obscure complex interactions predict more widespread synchronization. To permit more realistic simulations, we made a cast of blood vessels in a rat kidney, performed micro-computed tomography at 2.5-μm resolution, and recorded three-dimensional coordinates of arteries, afferent arterioles, and glomeruli. Nonterminal branches of arcuate arteries form treelike structures requiring two to six bifurcations to reach terminal branches at the tree tops. Terminal arterial structures were either paired branches at the tops of the arterial trees, from which 52.6% of all afferent arterioles originated, or unpaired arteries not at the tree tops, yielding the other 22.9%; the other 24.5% originated directly from nonterminal arteries. Afferent arterioles near the corticomedullary boundary were longer than those farther away, suggesting that juxtamedullary nephrons have longer afferent arterioles. The distance separating origins of pairs of afferent arterioles varied randomly. The results suggest an irregular-network tree structure with vascular nodes, where arteriolar activity and local blood pressure interact. Copyright © 2017 the American Physiological Society.

  20. Micro-Computed Tomography of Fatigue Microdamage in Cortical Bone Using a Barium Sulfate Contrast Agent

    PubMed Central

    Leng, Huijie; Wang, Xiang; Ross, Ryan D.; Niebur, Glen L.; Roeder, Ryan K.

    2008-01-01

    Accumulation of microdamage during fatigue can lead to increased fracture susceptibility in bone. Current techniques for imaging microdamage in bone are inherently destructive and two-dimensional. Therefore, the objective of this study was to image the accumulation of fatigue microdamage in cortical bone using micro-computed tomography (micro-CT) with a barium sulfate (BaSO4) contrast agent. Two symmetric notches were machined on the tensile surface of bovine cortical bone beams in order to generate damage ahead of the stress concentrations during four-point bending fatigue. Specimens were loaded to a specified number of cycles or until one notch fractured, such that the other notch exhibited the accumulation of microdamage prior to fracture. Microdamage ahead of the notch was stained in vitro by precipitation of BaSO4 and imaged using micro-CT. Reconstructed images showed a distinct region of bright voxels around the notch tip or along propagating cracks due to the presence of BaSO4, which was verified by backscattered electron imaging and energy dispersive spectroscopy. The shape of the stained region ahead of the notch tip was consistent with principal strain contours calculated by finite element analysis. The relative volume of the stained region was correlated with the number of loading cycles by non-linear regression using a power-law. This study demonstrates new methods for the non-destructive and three-dimensional detection of fatigue microdamage accumulation in cortical bone in vitro, which may be useful to gain further understanding into the role of microdamage in bone fragility. PMID:18443659

  1. Automated segmentation of synchrotron radiation micro-computed tomography biomedical images using Graph Cuts and neural networks

    NASA Astrophysics Data System (ADS)

    Alvarenga de Moura Meneses, Anderson; Giusti, Alessandro; de Almeida, André Pereira; Parreira Nogueira, Liebert; Braz, Delson; Cely Barroso, Regina; deAlmeida, Carlos Eduardo

    2011-12-01

    Synchrotron Radiation (SR) X-ray micro-Computed Tomography (μCT) enables magnified images to be used as a non-invasive and non-destructive technique with a high space resolution for the qualitative and quantitative analyses of biomedical samples. The research on applications of segmentation algorithms to SR-μCT is an open problem, due to the interesting and well-known characteristics of SR images for visualization, such as the high resolution and the phase contrast effect. In this article, we describe and assess the application of the Energy Minimization via Graph Cuts (EMvGC) algorithm for the segmentation of SR-μCT biomedical images acquired at the Synchrotron Radiation for MEdical Physics (SYRMEP) beam line at the Elettra Laboratory (Trieste, Italy). We also propose a method using EMvGC with Artificial Neural Networks (EMANNs) for correcting misclassifications due to intensity variation of phase contrast, which are important effects and sometimes indispensable in certain biomedical applications, although they impair the segmentation provided by conventional techniques. Results demonstrate considerable success in the segmentation of SR-μCT biomedical images, with average Dice Similarity Coefficient 99.88% for bony tissue in Wistar Rats rib samples (EMvGC), as well as 98.95% and 98.02% for scans of Rhodnius prolixus insect samples (Chagas's disease vector) with EMANNs, in relation to manual segmentation. The techniques EMvGC and EMANNs cope with the task of performing segmentation in images with the intensity variation due to phase contrast effects, presenting a superior performance in comparison to conventional segmentation techniques based on thresholding and linear/nonlinear image filtering, which is also discussed in the present article.

  2. Dual-Energy Micro-Computed Tomography Imaging of Radiation-Induced Vascular Changes in Primary Mouse Sarcomas

    SciTech Connect

    Moding, Everett J.; Clark, Darin P.; Qi, Yi; Li, Yifan; Ma, Yan; Ghaghada, Ketan; Johnson, G. Allan; Kirsch, David G.; Badea, Cristian T.

    2013-04-01

    Purpose: To evaluate the effects of radiation therapy on primary tumor vasculature using dual-energy (DE) micro-computed tomography (micro-CT). Methods and Materials: Primary sarcomas were generated with mutant Kras and p53. Unirradiated tumors were compared with tumors irradiated with 20 Gy. A liposomal-iodinated contrast agent was administered 1 day after treatment, and mice were imaged immediately after injection (day 1) and 3 days later (day 4) with DE micro-CT. CT-derived tumor sizes were used to assess tumor growth. After DE decomposition, iodine maps were used to assess tumor fractional blood volume (FBV) at day 1 and tumor vascular permeability at day 4. For comparison, tumor vascularity and vascular permeability were also evaluated histologically by use of CD31 immunofluorescence and fluorescently-labeled dextrans. Results: Radiation treatment significantly decreased tumor growth from day 1 to day 4 (P<.05). There was a positive correlation between CT measurement of tumor FBV on day 1 and extravasated iodine on day 4 with microvascular density (MVD) on day 4 (R{sup 2}=0.53) and dextran accumulation (R{sup 2}=0.63) on day 4, respectively. Despite no change in MVD measured by histology, tumor FBV significantly increased after irradiation as measured by DE micro-CT (0.070 vs 0.091, P<.05). Both dextran and liposomal-iodine accumulation in tumors increased significantly after irradiation, with dextran fractional area increasing 5.2-fold and liposomal-iodine concentration increasing 4.0-fold. Conclusions: DE micro-CT is an effective tool for noninvasive assessment of vascular changes in primary tumors. Tumor blood volume and vascular permeability increased after a single therapeutic dose of radiation treatment.

  3. A generic, geometric cocalibration method for a combined system of fluorescence molecular tomography and microcomputed tomography with arbitrarily shaped objects

    SciTech Connect

    Fu Jianwei; Yang Xiaoquan; Wang Kan; Luo Qingming; Gong Hui

    2011-12-15

    Purpose: A combined system of fluorescence molecular tomography and microcomputed tomography (FMT and mCT) can provide molecular and anatomical information of small animals in a single study with intrinsically coregistered images. The anatomical information provided by the mCT subsystem is commonly used as a reference to locate the fluorophore distribution or as a priori structural information to improve the performance of FMT. Therefore, the transformation between the coordinate systems of the subsystem needs to be determined in advanced. Methods: A cocalibration method for the combined system of FMT and mCT is proposed. First, linear models are adopted to describe the galvano mirrors and the charge-coupled device (CCD) camera in the FMT subsystem. Second, the position and orientation of the galvano mirrors are determined with the input voltages of the galvano mirrors and the markers, whose positions are predetermined. The position, orientation and normalized pixel size of the CCD camera are obtained by analysing the projections of a point-like marker at different positions. Finally, the orientation and position of sources and the corresponding relationship between the detectors and their projections on the image plane are predicted. Because the positions of the markers are acquired with mCT, the registration of the FMT and mCT could be realized by direct image fusion. Results: The accuracy and consistency of this method in the presence of noise is evaluated by computer simulation. Next, a practical implementation for an experimental FMT and mCT system is carried out and validated. The maximum prediction error of the source positions on the surface of a cylindrical phantom is within 0.375 mm and that of the projections of a point-like marker is within 0.629 pixel. Finally, imaging experiments of the fluorophore distribution in a cylindrical phantom and a phantom with a complex shape demonstrate the feasibility of the proposed method. Conclusions: This method is

  4. Bone Histology and Primary Growth Rates in Hatchling Titanosaurs from Madagascar: New Insights from Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Bagley, B. C.; Whitney, M.; Rogers, K. C.

    2012-12-01

    Sauropods are the largest known terrestrial vertebrates and exhibit a greater ontogenetic variation in body size than any other taxon. More than 120 species of sauropods are known from the Jurassic and Cretaceous, and a wealth of specimens documents their enormous adult body sizes. Juvenile sauropods, in contrast, are rare. Though titanosaur eggs containing embryos have been recovered, to date the smallest known post-hatching juveniles are only a little less than half of known adult size, and details of the earliest stages of sauropod ontogeny remain particularly poorly understood. Here we report on two partial skeletons of hatchling Rapetosaurus krausei, a titanosaur from the Upper Cretaceous Maevarano Formation of Madagascar, and provide important new data on primary early stage growth rates in sauropods. The two partial skeletons come from different localities in the Anembalemba Member of the Maevarano Formation. There is no duplication of elements for either specimen. Comparison of greatest length ratios for appendicular elements to those of a complete sub-adult Rapetosaurus confirms that there are only two individuals present, that there is no significant allometry in Rapetosaurus postcranial ontogeny, and that each individual is less than 15% adult size. The smaller specimen includes a sacral neural arch, three caudal centra, three caudal neural arches, left pubis, right femur (maximum length [ml] = 19.3 cm), tibia (ml = 12.7 cm), and metacarpal III, left and right fibulae, humeri, and metatarsal I, and a phalanx. The larger specimen includes a caudal centrum and neural arch, right metacarpal I, right tibia (ml = 17.9 cm), and left metacarpal IV. In order to non-destructively sample these exceptional Rapetosaurus juvenile elements, we employed micro-computed tomography to garner bone histology data. The micro-computed tomography was carried out using an X5000 high-resolution microfocus X-ray CT system located in the Department of Earth Sciences, University of

  5. A Comparison of Three LISP Interpreters for MS-DOS-Based Microcomputers

    PubMed Central

    Kahane, Stephen N.; Johannes, Richard S.

    1985-01-01

    We report a comparison of three commercially available LISP interpreters running on MS-DOS-based microcomputers. Marked differences were found between the different products' memory addressing abilities, error handling and debugging facilities. Editing tools, tutoring environments, windowing, graphic capabilities, operating system and port call facilities are also contrasted. Speed was tested via a group of LISP functions (benchmarks) that attempt to isolate list manipulation, iteration, function calling, recursion and mathematical calculation performance.

  6. Characterization of Dilatant Shear Bands in Castlegate Sandstone Using Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Rosenthal, R. E.; Issen, K. A.; Richards, M. C.; Ingraham, M. D.

    2016-12-01

    Deformation bands in granular rock are thin tabular zones of localized shear and/or volumetric strain, which affect permeability and can impact fluid flow, extraction and storage. The present work characterizes dilatant shear bands formed in Castlegate sandstone (a high porosity reservoir analog) during true triaxial laboratory testing (Ingraham et al., 2013a) at low mean stresses. X-ray micro-computed tomography (micro-CT) scans produced 3-dimensional voxel files containing density information of tested specimens. Micro-CT data were thresholded to extract the least dense voxels, corresponding to pore space and localized dilation. Plane fits were determined by a custom algorithm that calculated the angle between the band normal and maximum compression direction. For tests at the same mean stress, the band angle is lower when intermediate principal stress approaches minimum compression and higher when it approaches maximum compression. Micro-CT band angles were compared to angles from the specimen jackets (Ingraham et al., 2013a), and band angles from plane fits through located acoustic emissions (AE) events (Ingraham et al. 2013b). For non-axisymmetric stress states (three unique principal stresses), one primary dilatant shear band formed in each specimen. Occasionally, secondary bands traversing part of the specimen were also identified. The principal band angles from the micro-CT scans were on average within 3 degrees of the jacket angles and within 9 degrees of AE angles. For axisymmetric stress states (intermediate principal stress equal to maximum or minimum compression) micro-CT results reveal multiple conjugate and/or parallel bands. Each jacket angle correlated to a micro-CT angle within 4 degrees. Micro-CT results also reveal that, regardless of stress state, each band is comprised of a network of interconnected pore space pathways meandering between grain clusters, as opposed to an opening fracture/joint. Ingraham MD, KA Issen, DJ Holcomb, 2013a, J

  7. Contrast-enhanced micro-computed tomography of fatigue microdamage accumulation in human cortical bone.

    PubMed

    Landrigan, Matthew D; Li, Jiliang; Turnbull, Travis L; Burr, David B; Niebur, Glen L; Roeder, Ryan K

    2011-03-01

    Conventional methods used to image and quantify microdamage accumulation in bone are limited to histological sections, which are inherently invasive, destructive, two-dimensional, and tedious. These limitations inhibit investigation of microdamage accumulation with respect to volumetric spatial variation in mechanical loading, bone mineral density, and microarchitecture. Therefore, the objective of this study was to investigate non-destructive, three-dimensional (3-D) detection of microdamage accumulation in human cortical bone using contrast-enhanced micro-computed tomography (micro-CT), and to validate micro-CT measurements against conventional histological methods. Unloaded controls and specimens loaded in cyclic uniaxial tension to a 5% and 10% reduction in secant modulus were labeled with a precipitated BaSO₄ stain for micro-CT and basic fuchsin for histomorphometry. Linear microcracks were similarly labeled by BaSO₄ and basic fuchsin as shown by backscattered electron microscopy and light microscopy, respectively. The higher X-ray attenuation of BaSO₄ relative to the bone extracellular matrix provided enhanced contrast for the detection of damage that was otherwise not able to be detected by micro-CT prior to staining. Therefore, contrast-enhanced micro-CT was able to nondestructively detect the presence, 3-D spatial location, and accumulation of fatigue microdamage in human cortical bone specimens in vitro. Microdamage accumulation was quantified on segmented micro-CT reconstructions as the ratio of BaSO₄ stain volume (SV) to total bone volume (BV). The amount of microdamage measured by both micro-CT (SV/BV) and histomorphometry (Cr.N, Cr.Dn, Cr.S.Dn) progressively increased from unloaded controls to specimens loaded to a 5% and 10% reduction in secant modulus (p < 0.001). Group means for micro-CT measurements of damage accumulation were strongly correlated to those using histomorphometry (p < 0.05), validating the new methods. Limitations of the new

  8. Micro-computed tomography and nuclear magnetic resonance imaging for noninvasive, live-mouse cholangiography.

    PubMed

    Tabibian, James H; Macura, Slobodan I; O'Hara, Steven P; Fidler, Jeff L; Glockner, James F; Takahashi, Naoki; Lowe, Val J; Kemp, Bradley J; Mishra, Prasanna K; Tietz, Pamela S; Splinter, Patrick L; Trussoni, Christy E; LaRusso, Nicholas F

    2013-06-01

    The cholangiopathies are a diverse group of biliary tract disorders, many of which lack effective treatment. Murine models are an important tool for studying their pathogenesis, but existing noninvasive methods for assessing biliary disease in vivo are not optimal. Here we report our experience with using micro-computed tomography (microCT) and nuclear magnetic resonance (MR) imaging to develop a technique for live-mouse cholangiography. Using mdr2 knockout (mdr2KO, a model for primary sclerosing cholangitis (PSC)), bile duct-ligated (BDL), and normal mice, we performed in vivo: (1) microCT on a Siemens Inveon PET/CT scanner and (2) MR on a Bruker Avance 16.4 T spectrometer, using Turbo Rapid Acquisition with Relaxation Enhancement, IntraGate Fast Low Angle Shot, and Half-Fourier Acquisition Single-shot Turbo Spin Echo methods. Anesthesia was with 1.5-2.5% isoflurane. Scans were performed with and without contrast agents (iodipamide meglumine (microCT), gadoxetate disodium (MR)). Dissection and liver histology were performed for validation. With microCT, only the gallbladder and extrahepatic bile ducts were visualized despite attempts to optimize timing, route, and dose of contrast. With MR, the gallbladder, extra-, and intrahepatic bile ducts were well-visualized in mdr2KO mice; the cholangiographic appearance was similar to that of PSC (eg, multifocal strictures) and could be improved with contrast administration. In BDL mice, MR revealed cholangiographically distinct progressive dilation of the biliary tree without ductal irregularity. In normal mice, MR allowed visualization of the gallbladder and extrahepatic ducts, but only marginal visualization of the diminutive intrahepatic ducts. One mouse died during microCT and MR imaging, respectively. Both microCT and MR scans could be obtained in ≤20 min. We, therefore, demonstrate that MR cholangiography can be a useful tool for longitudinal studies of the biliary tree in live mice, whereas microCT yields

  9. Micro-Computed Tomography Evaluation of Human Fat Grafts in Nude Mice

    PubMed Central

    Chung, Michael T.; Hyun, Jeong S.; Lo, David D.; Montoro, Daniel T.; Hasegawa, Masakazu; Levi, Benjamin; Januszyk, Michael; Longaker, Michael T.

    2013-01-01

    Background Although autologous fat grafting has revolutionized the field of soft tissue reconstruction and augmentation, long-term maintenance of fat grafts is unpredictable. Recent studies have reported survival rates of fat grafts to vary anywhere between 10% and 80% over time. The present study evaluated the long-term viability of human fat grafts in a murine model using a novel imaging technique allowing for in vivo volumetric analysis. Methods Human fat grafts were prepared from lipoaspirate samples using the Coleman technique. Fat was injected subcutaneously into the scalp of 10 adult Crl:NU-Foxn1nu CD-1 male mice. Micro-computed tomography (CT) was performed immediately following injection and then weekly thereafter. Fat volume was rendered by reconstructing a three-dimensional (3D) surface through cubic-spline interpolation. Specimens were also harvested at various time points and sections were prepared and stained with hematoxylin and eosin (H&E), for macrophages using CD68 and for the cannabinoid receptor 1 (CB1). Finally, samples were explanted at 8- and 12-week time points to validate calculated micro-CT volumes. Results Weekly CT scanning demonstrated progressive volume loss over the time course. However, volumetric analysis at the 8- and 12-week time points stabilized, showing an average of 62.2% and 60.9% survival, respectively. Gross analysis showed the fat graft to be healthy and vascularized. H&E analysis and staining for CD68 showed minimal inflammatory reaction with viable adipocytes. Immunohistochemical staining with anti-human CB1 antibodies confirmed human origin of the adipocytes. Conclusions Studies assessing the fate of autologous fat grafts in animals have focused on nonimaging modalities, including histological and biochemical analyses, which require euthanasia of the animals. In this study, we have demonstrated the ability to employ micro-CT for 3D reconstruction and volumetric analysis of human fat grafts in a mouse model. Importantly

  10. Three-dimensional microstructural investigation of high magnetization nano-micro composite fluids using x-ray microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Borbáth, T.; Borbáth, I.; Günther, S.; Marinica, O.; Vékás, L.; Odenbach, S.

    2014-05-01

    X-ray microcomputed tomography was used in a three-dimensional investigation of the microstructure of suspensions of multi-domain soft iron particles in magnetic nanofluids. The measurements were performed using two different approaches: with the sample kept frozen, and with the sample under the effect of an external magnetic field. Results show that even a relatively low magnetic field gradient drives the micron-sized iron particles towards the stronger field and thus leads to a redistribution of the ferromagnetic particles in the magnetic nanofluid. Three-dimensional images of the internal microstructure of the composite magnetizable fluid (CMF) were obtained not only for the nano-micro composite system placed in a closed sample holder, but also for the spikes formed at the CMF free surface. It was demonstrated that x-ray microcomputed tomography is an efficient way to investigate the distribution and chain formation of ferromagnetic microparticles in a magnetic nanofluid carrier allowing an analysis even at a single particle level.

  11. Micro-computed tomography assisted distal femur metaphyseal blunt punch compression for determining trabecular bone strength in mice.

    PubMed

    Sankar, Uma; Pritchard, Zachary J; Voor, Michael J

    2016-05-03

    Shorter generation time and the power of genetic manipulation make mice an ideal model system to study bone biology as well as bone diseases. However their small size presents a challenge to perform strength measurements, particularly of the weight-bearing cancellous bone in the murine long bones. We recently developed an improved method to measure the axial compressive strength of the cancellous bone in the distal femur metaphysis in mice. Transverse micro-computed tomography image slices that are 7µm thick were used to locate the position where the epiphysis-metaphysis transition occurs. This enabled the removal of the distal femur epiphysis at the exact transition point exposing the full extent of metaphyseal trabecular bone, allowing more accurate and consistent measurement of its strength. When applied to a murine model system consisting of five month old male wild-type (WT) and Ca(2+)/calmodulin dependent protein kinase kinase 2 (CaMKK2) knockout (KO) Camkk2(-/-) mice that possess recorded differences in trabecular bone volume, data collected using this method showed good correlation between bone volume fraction and strength of trabecular bone. In combination with micro-computed tomography and histology, this method will provide a comprehensive and consistent assessment of the microarchitecture and tissue strength of the cancellous bone in murine mouse models.

  12. 3D-Microarchitectural patterns of Hyperostosis frontalis interna: a micro-computed tomography study in aged women.

    PubMed

    Bracanovic, Djurdja; Djonic, Danijela; Nikolic, Slobodan; Milovanovic, Petar; Rakocevic, Zoran; Zivkovic, Vladimir; Djuric, Marija

    2016-11-01

    Although seen frequently during dissections and autopsies, Hyperostosis frontalis interna (HFI) - a morphological pattern of the frontal bone thickening - is often ignored and its nature and development are not yet understood sufficiently. Current macroscopic classification defines four grades/stages of HFI based on the morphological appearance and size of the affected area; however, it is unclear if these stages also depict the successive phases in the HFI development. Here we assessed 3D-microarchitecture of the frontal bone in women with various degrees of HFI expression and in an age- and sex-matched control group, hypothesizing that the bone microarchitecture bears imprints of the pathogenesis of HFI and may clarify the phases of its development. Frontal bone samples were collected during routine autopsies from 20 women with HFI (age: 69.9 ± 11.1 years) and 14 women without HFI (age: 74.1 ± 9.7 years). We classified the HFI samples into four groups, each group demonstrating different macroscopic type or stage of HFI. All samples were scanned by micro-computed tomography to evaluate 3D bone microarchitecture in the following regions of interest: total sample, outer table, diploe and inner table. Our results revealed that, compared to the control group, the women with HFI showed a significantly increased bone volume fraction in the region of diploe, along with significantly thicker and more plate-like shaped trabeculae and reduced trabecular separation and connectivity density. Moreover, the inner table of the frontal bone in women with HFI displayed significantly increased total porosity and mean pore diameter compared to controls. Microstructural reorganization of the frontal bone in women with HFI was also reflected in significantly higher porosity and lower bone volume fraction in the inner vs. outer table due to an increased number of pores larger than 100 μm. The individual comparisons between the control group and different macroscopic stages of

  13. A Micro-Computed Tomography Technique to Study the Quality of Fibre Optics Embedded in Composite Materials

    PubMed Central

    Chiesura, Gabriele; Luyckx, Geert; Voet, Eli; Lammens, Nicolas; Van Paepegem, Wim; Degrieck, Joris; Dierick, Manuel; Van Hoorebeke, Luc; Vanderniepen, Pieter; Sulejmani, Sanne; Sonnenfeld, Camille; Geernaert, Thomas; Berghmans, Francis

    2015-01-01

    Quality of embedment of optical fibre sensors in carbon fibre-reinforced polymers plays an important role in the resultant properties of the composite, as well as for the correct monitoring of the structure. Therefore, availability of a tool able to check the optical fibre sensor-composite interaction becomes essential. High-resolution 3D X-ray Micro-Computed Tomography, or Micro-CT, is a relatively new non-destructive inspection technique which enables investigations of the internal structure of a sample without actually compromising its integrity. In this work the feasibility of inspecting the position, the orientation and, more generally, the quality of the embedment of an optical fibre sensor in a carbon fibre reinforced laminate at unit cell level have been proven. PMID:25961383

  14. Microstructural study of the lunate in stage III Kienböck's disease with micro-computed tomography imaging.

    PubMed

    Xiong, G; Xiao, Z; Wang, H; Guo, S; Tao, J

    2016-08-24

    Seventeen fresh lunates with stage III Kienböck's disease were scanned with micro-computed tomography. Four regions of interest were selected to measure trabecular parameters, which were compared with those from normal lunates. Within the three regions in the distal surface, there was more compact trabecular bone in the middle region when compared with the palmar and dorsal regions. In the central part, the trabeculae of the Kienböck's lunates were much thicker than those in normal lunates. The diameters of the palmar nutrient foramina of the Kienböck's lunates were significantly smaller than those in normal lunates. In affected lunates, the bony disruptions were mostly located in the palmar or dorsal areas, which were shown from trabecular bone structure analysis to be structurally weaker. This leads to separation of the distal part of the fractured bone, disruption of the blood supply, poor bone remodelling and proneness to secondary fracture and eventual collapse.

  15. Application of X-ray microcomputed tomography in the characterization of irradiated nuclear fuel and material specimens

    DOE PAGES

    Silva, Chinthaka M.; Snead, Lance Lewis; Hunn, John D.; ...

    2015-08-03

    X-ray microcomputed tomography (µCT) was applied in characterizing the internal structures of a number of irradiated materials, including carbon-carbon fibre composites, nuclear-grade graphite and tristructural isotropic-coated fuel particles. Local cracks in carbon-carbon fibre composites associated with their synthesis process were observed with µCT without any destructive sample preparation. Pore analysis of graphite samples was performed quantitatively, and qualitative analysis of pore distribution was accomplished. It was also shown that high-resolution µCT can be used to probe internal layer defects of tristructural isotropic-coated fuel particles to elucidate the resulting high release of radioisotopes. Layer defects of sizes ranging from 1 tomore » 5 µm and up could be isolated by to-mography. As an added advantage, µCT could also be used to identify regions with high densities of radioisotopes to deter-mine the proper plane and orientation of particle mounting for further analytical characterization, such as materialographic sectioning followed by optical and electron microscopy. Lastly, in fully ceramic matrix fuel forms, despite the highly absorbing matrix, characterization of tristructural isotropic-coated particles embedded in a silicon carbide matrix was accomplished usingµCT and related advanced image analysis techniques.« less

  16. Application of X-ray microcomputed tomography in the characterization of irradiated nuclear fuel and material specimens

    SciTech Connect

    Silva, Chinthaka M.; Snead, Lance Lewis; Hunn, John D.; Specht, Eliot D.; Terrani, Kurt A.; Katoh, Yutai

    2015-08-03

    X-ray microcomputed tomography (µCT) was applied in characterizing the internal structures of a number of irradiated materials, including carbon-carbon fibre composites, nuclear-grade graphite and tristructural isotropic-coated fuel particles. Local cracks in carbon-carbon fibre composites associated with their synthesis process were observed with µCT without any destructive sample preparation. Pore analysis of graphite samples was performed quantitatively, and qualitative analysis of pore distribution was accomplished. It was also shown that high-resolution µCT can be used to probe internal layer defects of tristructural isotropic-coated fuel particles to elucidate the resulting high release of radioisotopes. Layer defects of sizes ranging from 1 to 5 µm and up could be isolated by to-mography. As an added advantage, µCT could also be used to identify regions with high densities of radioisotopes to deter-mine the proper plane and orientation of particle mounting for further analytical characterization, such as materialographic sectioning followed by optical and electron microscopy. Lastly, in fully ceramic matrix fuel forms, despite the highly absorbing matrix, characterization of tristructural isotropic-coated particles embedded in a silicon carbide matrix was accomplished usingµCT and related advanced image analysis techniques.

  17. Application of X-ray microcomputed tomography in the characterization of irradiated nuclear fuel and material specimens.

    PubMed

    Silva, C M; Snead, L L; Hunn, J D; Specht, E D; Terrani, K A; Katoh, Y

    2015-11-01

    X-ray microcomputed tomography (μCT) was applied in characterizing the internal structures of a number of irradiated materials, including carbon-carbon fibre composites, nuclear-grade graphite and tristructural isotropic-coated fuel particles. Local cracks in carbon-carbon fibre composites associated with their synthesis process were observed with μCT without any destructive sample preparation. Pore analysis of graphite samples was performed quantitatively, and qualitative analysis of pore distribution was accomplished. It was also shown that high-resolution μCT can be used to probe internal layer defects of tristructural isotropic-coated fuel particles to elucidate the resulting high release of radioisotopes. Layer defects of sizes ranging from 1 to 5 μm and up could be isolated by tomography. As an added advantage, μCT could also be used to identify regions with high densities of radioisotopes to determine the proper plane and orientation of particle mounting for further analytical characterization, such as materialographic sectioning followed by optical and electron microscopy. In fully ceramic matrix fuel forms, despite the highly absorbing matrix, characterization of tristructural isotropic-coated particles embedded in a silicon carbide matrix was accomplished using μCT and related advanced image analysis techniques.

  18. Detection of mouse liver cancer via a parallel iterative shrinkage method in hybrid optical/microcomputed tomography imaging

    NASA Astrophysics Data System (ADS)

    Wu, Ping; Liu, Kai; Zhang, Qian; Xue, Zhenwen; Li, Yongbao; Ning, Nannan; Yang, Xin; Li, Xingde; Tian, Jie

    2012-12-01

    Liver cancer is one of the most common malignant tumors worldwide. In order to enable the noninvasive detection of small liver tumors in mice, we present a parallel iterative shrinkage (PIS) algorithm for dual-modality tomography. It takes advantage of microcomputed tomography and multiview bioluminescence imaging, providing anatomical structure and bioluminescence intensity information to reconstruct the size and location of tumors. By incorporating prior knowledge of signal sparsity, we associate some mathematical strategies including specific smooth convex approximation, an iterative shrinkage operator, and affine subspace with the PIS method, which guarantees the accuracy, efficiency, and reliability for three-dimensional reconstruction. Then an in vivo experiment on the bead-implanted mouse has been performed to validate the feasibility of this method. The findings indicate that a tiny lesion less than 3 mm in diameter can be localized with a position bias no more than 1 mm the computational efficiency is one to three orders of magnitude faster than the existing algorithms; this approach is robust to the different regularization parameters and the lp norms. Finally, we have applied this algorithm to another in vivo experiment on an HCCLM3 orthotopic xenograft mouse model, which suggests the PIS method holds the promise for practical applications of whole-body cancer detection.

  19. Comparative study on submillimeter flaws in stitched T-joint carbon fiber reinforced polymer by infrared thermography, microcomputed tomography, ultrasonic c-scan and microscopic inspection

    NASA Astrophysics Data System (ADS)

    Zhang, Hai; Hassler, Ulf; Genest, Marc; Fernandes, Henrique; Robitaille, Francois; Ibarra-Castanedo, Clemente; Joncas, Simon; Maldague, Xavier

    2015-10-01

    Stitching is used to reduce dry-core (incomplete infusion of T-joint core) and reinforce T-joint structure. However, it may cause new types of flaws, especially submillimeter flaws. Microscopic inspection, ultrasonic c-scan, pulsed thermography, vibrothermography, and laser spot thermography are used to investigate the internal flaws in a stitched T-joint carbon fiber-reinforced polymer (CFRP) matrix composites. Then, a new microlaser line thermography is proposed. Microcomputed tomography (microCT) is used to validate the infrared results. A comparison between microlaser line thermography and microCT is performed. It was concluded that microlaser line thermography can detect the internal submillimeter defects. However, the depth and size of the defects can affect the detection results. The microporosities with a diameter of less than 54 μm are not detected in the microlaser line thermography results. Microlaser line thermography can detect the microporosity (a diameter of 0.162 mm) from a depth of 90 μm. However, it cannot detect the internal microporosity (a diameter of 0.216 mm) from a depth of 0.18 mm. The potential causes are given. Finally, a comparative study is conducted.

  20. The local administration of parathyroid hormone encourages the healing of bone defects in the rat calvaria: Micro-computed tomography, histological and histomorphometric evaluation.

    PubMed

    Auersvald, Caroline Moreira; Santos, Felipe Rychuv; Nakano, Mayara Mytie; Leoni, Graziela Bianchi; de Sousa Neto, Manoel Damião; Scariot, Rafaela; Giovanini, Allan Fernando; Deliberador, Tatiana Miranda

    2017-07-01

    To evaluate the effect of a single-dose local administration of PTH on bone healing in rat calvarial bone defects by means of micro-computed tomography, histological and histomorphometric analysis. Critical-size cranial osteotomy defects were created in 42 male rats. The animals were randomly divided into 3 groups. In the C Group, the bone defect was only filled with a blood clot. In the S Group, it was filled with a collagen sponge and covered with bovine cortical membrane. In the PTH Group, the defect was filled with a collagen sponge soaked with PTH and covered with bovine cortical membrane. The groups were further split in two for euthanasia 15 and 60days post-surgery. Data was statistically analyzed with t-tests for independent samples or the nonparametric Mann-Whitney test when applicable. Intragroup comparisons were analyzed with paired t-tests (p<0.05). Micro-CT analysis results did not demonstrate statistically significant intergroup differences. At 15days post-surgery, the histomorphometric analysis showed that the PTH Group exhibited a significantly higher percentage of bone formation compared with the S Group. At 60days post-surgery, a higher percentage of new bone was observed in the PTH group. The results suggest that the local administration of PTH encouraged the bone healing in critical-size calvarial defects in rats. Copyright © 2017 Elsevier Ltd. All rights reserved.

  1. If the skull fits: magnetic resonance imaging and microcomputed tomography for combined analysis of brain and skull phenotypes in the mouse.

    PubMed

    Nieman, Brian J; Blank, Marissa C; Roman, Brian B; Henkelman, R Mark; Millen, Kathleen J

    2012-10-17

    The mammalian brain and skull develop concurrently in a coordinated manner, consistently producing a brain and skull that fit tightly together. It is common that abnormalities in one are associated with related abnormalities in the other. However, this is not always the case. A complete characterization of the relationship between brain and skull phenotypes is necessary to understand the mechanisms that cause them to be coordinated or divergent and to provide perspective on the potential diagnostic or prognostic significance of brain and skull phenotypes. We demonstrate the combined use of magnetic resonance imaging and microcomputed tomography for analysis of brain and skull phenotypes in the mouse. Co-registration of brain and skull images allows comparison of the relationship between phenotypes in the brain and those in the skull. We observe a close fit between the brain and skull of two genetic mouse models that both show abnormal brain and skull phenotypes. Application of these three-dimensional image analyses in a broader range of mouse mutants will provide a map of the relationships between brain and skull phenotypes generally and allow characterization of patterns of similarities and differences.

  2. Application of 3-d echocardiography and gated micro-computed tomography to assess cardiomyopathy in a mouse model of duchenne muscular dystrophy.

    PubMed

    Bondoc, Andrew B; Detombe, Sarah; Dunmore-Buyze, Joy; Gutpell, Kelly M; Liu, Linshan; Kaszuba, Amanda; Han, Seongryoung; McGirr, Rebecca; Hadway, Jennifer; Drangova, Maria; Hoffman, Lisa M

    2014-12-01

    The purpose of this study was to measure changes in cardiac function as cardiomyopathy progresses in a mouse model of Duchenne muscular dystrophy using 3-D ECG-gated echocardiography. This study is the first to correlate cardiac volumes acquired using 3-D echocardiography with those acquired using retrospectively gated micro-computed tomography (CT). Both were further compared with standard M-mode echocardiography and histologic analyses. We found that although each modality measures a decrease in cardiac function as disease progresses in mdx/utrn(-/-) mice (n = 5) compared with healthy C57BL/6 mice (n = 8), 3-D echocardiography has higher agreement with gold-standard measurements acquired by gated micro-CT, with little standard deviation between measurements. M-Mode echocardiography measurements, in comparison, exhibit considerably greater variability and user bias. Given the radiation dose associated with micro-CT and the geometric assumptions made in M-mode echocardiography to calculate ventricular volume, we suggest that use of 3-D echocardiography has important advantages that may allow for the measurement of early disease changes that occur before overt cardiomyopathy. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

  3. If the skull fits: magnetic resonance imaging and microcomputed tomography for combined analysis of brain and skull phenotypes in the mouse

    PubMed Central

    Blank, Marissa C.; Roman, Brian B.; Henkelman, R. Mark; Millen, Kathleen J.

    2012-01-01

    The mammalian brain and skull develop concurrently in a coordinated manner, consistently producing a brain and skull that fit tightly together. It is common that abnormalities in one are associated with related abnormalities in the other. However, this is not always the case. A complete characterization of the relationship between brain and skull phenotypes is necessary to understand the mechanisms that cause them to be coordinated or divergent and to provide perspective on the potential diagnostic or prognostic significance of brain and skull phenotypes. We demonstrate the combined use of magnetic resonance imaging and microcomputed tomography for analysis of brain and skull phenotypes in the mouse. Co-registration of brain and skull images allows comparison of the relationship between phenotypes in the brain and those in the skull. We observe a close fit between the brain and skull of two genetic mouse models that both show abnormal brain and skull phenotypes. Application of these three-dimensional image analyses in a broader range of mouse mutants will provide a map of the relationships between brain and skull phenotypes generally and allow characterization of patterns of similarities and differences. PMID:22947655

  4. Visualizing polymeric bioresorbable scaffolds with three-dimensional image reconstruction using contrast-enhanced micro-computed tomography.

    PubMed

    Tu, Sheng; Hu, Fudong; Cai, Wei; Xiao, Liyan; Zhang, Linlin; Zheng, Hong; Jiang, Qiong; Chen, Lianglong

    2017-05-01

    There are no previous studies showing how to visualize polymeric bioresorbable scaffolds (BRSs) by micro-computed tomography (mCT). There are no previous studies showing how to visualize polymeric bioresorbable scaffolds (BRSs) by micro-computed tomography (mCT). This study aimed to explore the feasibility of detecting polymeric BRS with 3-dimensional reconstruction of BRS images by contrast-enhanced mCT and to determine the optimal imaging settings. BRSs, made of poly-L-lactic acid (PLLA), were implanted in coronary bifurcation models. Five treatments were conducted to examine an optimal condition for imaging BRSs: Baseline treatment, samples were filled with normal saline and scanned with mCT immediately; Treatment-1, -2, -3 and -4, samples were filled with contrast medium and scanned with mCT immediately and 1, 2 and 3 h thereafter, corresponding to soaking time of contrast medium of 0, 1, 2 and 3 h. Compared to Baseline, mCT scanning completely discriminate the scaffold struts from the vascular lumen immediately after filling the samples with contrast agent but not from the vascular wall until the contrast agent soaking time was more than 2 h (Treatment-3 and -4). By setting 10-15 HU as a cut-point of CT values, the scaffold strut detectable rate at Baseline and Teatment-1, -2, -3 and -4 were 1.23 ± 0.31%, 1.65 ± 0.26%, 58.14 ± 12.84%, 97.97 ± 1.43% and 98.90 ± 0.38%, respectively (Treatment-3 vs. Treatment-2, p < 0.01); meanwhile, the success rate of 3D BRS reconstruction with high quality images at Baseline and Teatment-1, -2, -3 and -4 were 1.23%, 1.65%, 58.14%, 97.97% and 98.90%, respectively (Treatment-3 vs. Treatment-2, p < 0.01). In conclusions, reconstruction of 3D BRS images is technically feasible by contrast-enhanced mCT and soaking time of contrast agent for more than 2 h is necessary for complete separation of scaffold struts from the surrounding structures in the phantom samples.

  5. Three-dimensional observation of the mouse embryo by micro-computed tomography: Meckel's cartilage, otocyst, and/or muscle of tongue.

    PubMed

    Aoyagi, Hidekazu; Iwasaki, Shin-ichi; Yoshizawa, Hideki; Tsuchikawa, Kohzo

    2012-07-01

    Three-dimensional observation during embryogenesis is possible with micro-computed tomography, but there are no observations of organ size. In this paper, three examples of three-dimensional observation of organs by micro-CT are tried. At 13.0 days post-coitum, mouse embryos were fixed in 4% paraformaldehyde for 24 h and stained enbloc by osmium tetroxide overnight. The embryos were then embedded in paraffin using standard methods for 24 h. Specimens were analyzed by micro-computed tomography and image processing was performed. The entire Meckel's cartilage and its relation in the mandible, as well as the complex structure of the otocyst, are easily visualized. Although it is difficult to extract detailed structures of the tongue muscles, it is possible to identify the inner and external tongue muscles. Relation among the organs and other are easily visualized. Three-dimensional observation by micro-computed tomography is an important technology for visualization of embryogenesis and could be used in organ culture.

  6. Evaluating the microstructure of human brain tissues using synchrotron radiation-based micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Schulz, Georg; Morel, Anne; Imholz, Martha S.; Deyhle, Hans; Weitkamp, Timm; Zanette, Irene; Pfeiffer, Franz; David, Christian; Müller-Gerbl, Magdalena; Müller, Bert

    2010-09-01

    Minimally invasive deep brain neurosurgical interventions require a profound knowledge of the morphology of the human brain. Generic brain atlases are based on histology including multiple preparation steps during the sectioning and staining. In order to correct the distortions induced in the anisotropic, inhomogeneous soft matter and therefore improve the accuracy of brain atlases, a non-destructive 3D imaging technique with the required spatial and density resolution is of great significance. Micro computed tomography provides true micrometer resolution. The application to post mortem human brain, however, is questionable because the differences of the components concerning X-ray absorption are weak. Therefore, magnetic resonance tomography has become the method of choice for three-dimensional imaging of human brain. Because the spatial resolution of this method is limited, an alternative has to be found for the three-dimensional imaging of cellular microstructures within the brain. Therefore, the present study relies on the synchrotron radiationbased micro computed tomography in the recently developed grating-based phase contrast mode. Using data acquired at the beamline ID 19 (ESRF, Grenoble, France) we demonstrate that grating-based tomography yields premium images of human thalamus, which can be used for the correction of histological distortions by 3D non-rigid registration.

  7. Imaging of poly(α-hydroxy-ester) scaffolds with X-ray phase-contrast microcomputed tomography.

    PubMed

    Appel, Alyssa A; Larson, Jeffery C; Somo, Sami; Zhong, Zhong; Spicer, Patrick P; Kasper, F Kurtis; Garson, Alfred B; Zysk, Adam M; Mikos, Antonios G; Anastasio, Mark A; Brey, Eric M

    2012-11-01

    Porous scaffolds based on poly(α-hydroxy-esters) are under investigation in many tissue engineering applications. A biological response to these materials is driven, in part, by their three-dimensional (3D) structure. The ability to evaluate quantitatively the material structure in tissue-engineering applications is important for the continued development of these polymer-based approaches. X-ray imaging techniques based on phase contrast (PC) have shown a tremendous promise for a number of biomedical applications owing to their ability to provide a contrast based on alternative X-ray properties (refraction and scatter) in addition to X-ray absorption. In this research, poly(α-hydroxy-ester) scaffolds were synthesized and imaged by X-ray PC microcomputed tomography. The 3D images depicting the X-ray attenuation and phase-shifting properties were reconstructed from the measurement data. The scaffold structure could be imaged by X-ray PC in both cell culture conditions and within the tissue. The 3D images allowed for quantification of scaffold properties and automatic segmentation of scaffolds from the surrounding hard and soft tissues. These results provide evidence of the significant potential of techniques based on X-ray PC for imaging polymer scaffolds.

  8. Contrast-Enhanced X-Ray Micro-Computed Tomography as a Versatile Method for Anatomical Studies of Adult Zebrafish.

    PubMed

    Babaei, Fatemeh; Hong, Tony Liu Chi; Yeung, Kelvin; Cheng, Shuk Han; Lam, Yun Wah

    2016-08-01

    One attractive quality of zebrafish as a model organism for biological research is that transparency at early developmental stages allows the optical imaging of cellular and molecular events. However, this advantage cannot be applied to adult zebrafish. In this study, we explored the use of contrast-enhanced X-ray micro-computed tomography (microCT) on adult zebrafish in which the organism was stained with iodine, a simple and economical contrasting agent, after fixation. Tomographic reconstruction of the microCT data allowed the three-dimensional (3D) volumetric analyses of individual organs in adult zebrafish. Adipose tissues showed a higher affinity to iodine and were more strongly contrasted in microCT. As traditional histological techniques often involve dehydration steps that remove tissue lipids, iodine-contrasted microCT offers a convenient method for visualizing fat deposition in fish. Utilizing this advantage, we discovered a transient accumulation of lipids around the heart after ventricular amputation, suggesting a correlation between lipid distribution and heart regeneration. Taken together, microCT is a versatile technique that enables the 3D visualization of zebrafish organs, as well as other fish models, in their anatomical context. This simple method is a valuable new addition to the arsenal of techniques available to this model organism.

  9. Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer

    PubMed Central

    Mok, Pooi Ling; Leow, Sue Ngein; Koh, Avin Ee-Hwan; Mohd Nizam, Hairul Harun; Ding, Suet Lee Shirley; Luu, Chi; Ruhaslizan, Raduan; Wong, Hon Seng; Halim, Wan Haslina Wan Abdul; Ng, Min Hwei; Idrus, Ruszymah Binti Hj.; Chowdhury, Shiplu Roy; Bastion, Catherine Mae-Lynn; Subbiah, Suresh Kumar; Higuchi, Akon; Alarfaj, Abdullah A.; Then, Kong Yong

    2017-01-01

    Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases. PMID:28208719

  10. Ex vivo micro-computed tomography analysis of bleomycin-induced lung fibrosis for preclinical drug evaluation.

    PubMed

    Scotton, Chris J; Hayes, Brian; Alexander, Robert; Datta, Arnab; Forty, Ellen J; Mercer, Paul F; Blanchard, Andy; Chambers, Rachel C

    2013-12-01

    Research into the pathogenesis underlying the development of idiopathic pulmonary fibrosis is hampered by a repertoire of animal models that fail to recapitulate all the features of the human disease. Better use and understanding of what the animal models represent may improve clinical predictability. We interrogated ex vivo micro-computed tomography (CT) as a novel end-point measure in the mouse model of bleomycin-induced lung fibrosis (BILF), and to evaluate a therapeutic dosing regimen for preclinical drug evaluation. A detailed characterisation of BILF was performed using standard end-point measures (lung hydroxyproline and histology). High resolution micro-CT (∼13.7 μm voxel size) was evaluated for quantifying the extent and severity of lung fibrosis. The period from 14 to 28 days following bleomycin instillation represents progression of established fibrosis. A therapeutic dosing regimen during this period was validated using a transforming growth factor-β receptor-1 kinase inhibitor, and micro-CT provided a highly sensitive and quantitative measure of fibrosis. Moreover, fibrotic lesions did not completely resolve, but instead persisted for ≥6 months following a single insult with bleomycin. Ex vivo micro-CT analysis of BILF allows robust evaluation of therapeutic dosing once fibrosis is already well established, requiring fewer mice than conventional biochemical end-points.

  11. Nondestructive material characterization of meteorites with synchrotron-based high energy x-ray phase micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Liu, Huiqiang; Xiao, Tiqiao; Xie, Honglan; Fu, Yanan; Zhang, Xueliang; Fan, Xiaoxi

    2017-02-01

    Synchrotron radiation based x-ray propagation-based micro-computed tomography (SRPCT) has been widely used to nondestructively access 3D structural information in many fields in the last decade. However, for strongly absorbed objects with small density-differential compositions, conventional SRPCT technique fails in providing high-contrast images for visualization of objects characteristic information except edge-enhancements at interfaces or boundaries of samples. In this study, we successfully employed the SRPCT technique with phase retrieval, the high energy x-ray phase-attenuation-duality (PAD) algorithm, into nondestructive material characterization of invaluable meteorite samples due to the greatly enhanced phase-contrast of different bulk material areas, as compared to conventional SRPCT on equal dose basis. Our experimental results demonstrated the PAD-SRPCT technique is superior to conventional SRPCT technique to access density and structure distributions of different meteorite compositions with high density resolution, owing to the striking contrast-to-noise ratio (CNR). In addition, a new mass-density measurement method was presented to estimate the mass density of different compositions in the meteorite sample based on the calibration of the imaging system.

  12. Characterization of Fatigue Fractures in Closed-Cell Aluminum Foam Using x-ray Micro-Computed Tomography

    NASA Astrophysics Data System (ADS)

    Kafka, O. L.; Ingraham, M. D.; Morrison, D. J.; Issen, K. A.

    2014-03-01

    A post-mortem study of Alporas closed-cell aluminum foam specimens previously failed under strain-controlled fully reversed tension-compression fatigue was conducted using x-ray micro-computed tomography (μCT). Volumetric renders of the 3D structure of the material were produced. Fractures were identified and marked throughout voxel-based images of the specimens. This produced a 3D plot of fracture locations. At high strain amplitudes (0.175-0.5%), fractures formed an interconnected planar zone oriented approximately perpendicular to the loading axis; typically, the angle of the plane differed from that of a tension failure. Conversely, at low strain amplitudes (0.05-0.1%), short fractures have been formed diffusely within the specimen. In both cases, observed fractures were tortuous. Our previous work with surface strain mapping via digital image correlation (DIC) suggested that for all strain amplitudes, a crack, evidenced by a zone of high extensile strain, was formed and propagated through the material. This result was confirmed at high strain amplitudes, but not at low strain amplitudes. The discrepancy is attributed to three potential causes. Using DIC, short cracks cannot be accurately resolved with relatively coarse light intensity patterns. DIC images indicate fractures under load, while μCT imaging was conducted under zero load. Finally, the localized extension seen in DIC images could be attributed to strain with no resultant fractures.

  13. Application of X-ray micro-computed tomography on high-speed cavitating diesel fuel flows

    NASA Astrophysics Data System (ADS)

    Mitroglou, N.; Lorenzi, M.; Santini, M.; Gavaises, M.

    2016-11-01

    The flow inside a purpose built enlarged single-orifice nozzle replica is quantified using time-averaged X-ray micro-computed tomography (micro-CT) and high-speed shadowgraphy. Results have been obtained at Reynolds and cavitation numbers similar to those of real-size injectors. Good agreement for the cavitation extent inside the orifice is found between the micro-CT and the corresponding temporal mean 2D cavitation image, as captured by the high-speed camera. However, the internal 3D structure of the developing cavitation cloud reveals a hollow vapour cloud ring formed at the hole entrance and extending only at the lower part of the hole due to the asymmetric flow entry. Moreover, the cavitation volume fraction exhibits a significant gradient along the orifice volume. The cavitation number and the needle valve lift seem to be the most influential operating parameters, while the Reynolds number seems to have only small effect for the range of values tested. Overall, the study demonstrates that use of micro-CT can be a reliable tool for cavitation in nozzle orifices operating under nominal steady-state conditions.

  14. In Vivo Quantitative Assessment of Myocardial Structure, Function, Perfusion and Viability Using Cardiac Micro-computed Tomography

    PubMed Central

    van Deel, Elza; Ridwan, Yanto; van Vliet, J. Nicole; Belenkov, Sasha; Essers, Jeroen

    2016-01-01

    The use of Micro-Computed Tomography (MicroCT) for in vivo studies of small animals as models of human disease has risen tremendously due to the fact that MicroCT provides quantitative high-resolution three-dimensional (3D) anatomical data non-destructively and longitudinally. Most importantly, with the development of a novel preclinical iodinated contrast agent called eXIA160, functional and metabolic assessment of the heart became possible. However, prior to the advent of commercial MicroCT scanners equipped with X-ray flat-panel detector technology and easy-to-use cardio-respiratory gating, preclinical studies of cardiovascular disease (CVD) in small animals required a MicroCT technologist with advanced skills, and thus were impractical for widespread implementation. The goal of this work is to provide a practical guide to the use of the high-speed Quantum FX MicroCT system for comprehensive determination of myocardial global and regional function along with assessment of myocardial perfusion, metabolism and viability in healthy mice and in a cardiac ischemia mouse model induced by permanent occlusion of the left anterior descending coronary artery (LAD). PMID:26967592

  15. Anatomy research of nasolabial muscle structure in fetus with cleft lip: an iodine staining technique based on microcomputed tomography.

    PubMed

    Wu, Jiajun; Yin, Ningbei

    2014-05-01

    A thorough knowledge of the anatomic structure of the orbicularis oris of the upper lip and the nasalis in fetus with cleft lip is the key for the success of cleft lip repair. To understand the anatomic structure of the muscles of nasolabial region in fetus with cleft lip, the nasolabial tissues in 4 aborted fetuses with cleft lip were soaked for 7 days with iodine solution (Lugol solution of 3.75%) and were given micro-computed tomography. After the iodine solution permeated into the soft tissues, a good contrast was showed between muscle fibers and other fibrillar connective tissues. Through the observation of the obtained images, we found that most orbicularis oris fibers gathered into bundles with clear outline and only had slight deformation and displacement on the health side of the cleft of the unilateral incomplete cleft lip; however, in the lateral cleft, the muscle fibers not only had deformation and displacement but also were immature, disorganized, and not gathered into bundles. After being restored in Digital Imaging and Communications in Medicine format, the obtained images were then transferred into Materialise's interactive medical image control system, edited, and reconstructed into three-dimensional models. The models clearly showed the spatial relationship between the muscular tissues of the nasolabial region and the nasolabial outline in fetus with cleft lip.

  16. Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations.

    PubMed

    Hedayat, Assem; Nagy, Nicole; Packota, Garnet; Monteith, Judy; Allen, Darcy; Wysokinski, Tomasz; Zhu, Ning

    2016-05-01

    Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.

  17. Variation in Lateral Plate Quality in Threespine Stickleback from Fresh, Brackish and Marine Water: A Micro-Computed Tomography Study

    PubMed Central

    Reseland, Janne E.; Østbye, Kjartan; Haugen, Håvard J.; Vøllestad, Leif A.

    2016-01-01

    Introduction It is important to understand the drivers leading to adaptive phenotypic diversity within and among species. The threespine stickleback (Gasterosteus aculeatus) has become a model system for investigating the genetic and phenotypic responses during repeated colonization of fresh waters from the original marine habitat. During the freshwater colonization process there has been a recurrent and parallel reduction in the number of lateral bone plates, making it a suitable system for studying adaptability and parallel evolution. Objective The aim of this study was to investigate an alternative evolutionary path of lateral plate reduction, where lateral plates are reduced in size rather than number. Materials and Methods A total of 72 threespine stickleback individuals from freshwater (n = 54), brackish water (n = 27) and marine water (n = 9) were analysed using microcomputed tomography (μCT) to determine variation in size, thickness and structure of the lateral plates. Furthermore, whole-body bone volume, and bone volume, bone surface and porosity of lateral plate number 4 were quantified in all specimens from each environment. Results The results showed a significant difference in plate size (area and volume) among populations, where threespine stickleback from polymorphic freshwater and brackish water populations displayed lateral plates reduced in size (area and volume) compared to marine stickleback Conclusions Reduction of lateral plates in threespine stickleback in fresh and brackish water occurs by both plate loss and reduction in plate size (area and volume). PMID:27764140

  18. Imaging of Poly(α-hydroxy-ester) Scaffolds with X-ray Phase-Contrast Microcomputed Tomography

    PubMed Central

    Appel, Alyssa A.; Larson, Jeffery C.; Somo, Sami; Zhong, Zhong; Spicer, Patrick P.; Kasper, F. Kurtis; Garson, Alfred B.; Zysk, Adam M.; Mikos, Antonios G.; Anastasio, Mark A.

    2012-01-01

    Porous scaffolds based on poly(α-hydroxy-esters) are under investigation in many tissue engineering applications. A biological response to these materials is driven, in part, by their three-dimensional (3D) structure. The ability to evaluate quantitatively the material structure in tissue-engineering applications is important for the continued development of these polymer-based approaches. X-ray imaging techniques based on phase contrast (PC) have shown a tremendous promise for a number of biomedical applications owing to their ability to provide a contrast based on alternative X-ray properties (refraction and scatter) in addition to X-ray absorption. In this research, poly(α-hydroxy-ester) scaffolds were synthesized and imaged by X-ray PC microcomputed tomography. The 3D images depicting the X-ray attenuation and phase-shifting properties were reconstructed from the measurement data. The scaffold structure could be imaged by X-ray PC in both cell culture conditions and within the tissue. The 3D images allowed for quantification of scaffold properties and automatic segmentation of scaffolds from the surrounding hard and soft tissues. These results provide evidence of the significant potential of techniques based on X-ray PC for imaging polymer scaffolds. PMID:22607529

  19. 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.

  20. Is micro-computed tomography useful for wear assessment of ceramic femoral heads? A preliminary evaluation of volume measurements.

    PubMed

    Parrilli, Annapaola; Falcioni, Stefano; Fini, Milena; Affatato, Saverio

    2016-11-02

    Wear associated with hip components represents the main clinical problem in these patients, and it is important to develop new techniques for more accurate measurements of that wear. Currently, the gravimetric method is the gold standard for assessing mass measurements in preclinical evaluations. However, this method does not give other information such as volumetric loss or surface deviation. This work aimed to develop and validate a new technique to quantify ceramic volume loss from in vitro experiments using micro-computed tomography (micro-CT). An alumina (BIOLOX® forte) femoral head (Ø = 28 mm) was used. Mass and volume loss were approached by gravimetric method (using a four decimal place digital microbalance) and by using Skyscan 1176 microtomographic system, respectively. Standard error and coefficient of variance of both gravimetric and experimental groups demonstrated the reliability of the micro-CT analysis technique. In conclusion, the findings of the present study suggest that this new protocol could be considered an important tool for wear assessment and that we have found a reliable metrological protocol for volumetric analysis of ceramic femoral head prostheses, demonstrating that the micro-CT technique can be an important tool for wear assessment.

  1. Impact of mineral precipitation on flow and mixing in porous media determined by microcomputed tomography and MRI

    DOE PAGES

    Bray, Joshua M.; Lauchnor, Ellen G.; Redden, George D.; ...

    2016-12-21

    Here, precipitation reactions in porous media influence transport properties of the environment and can control advective and dispersive transport. In subsurface environments, mixing of saline groundwater or injected solutions for remediation with fresh groundwater can induce supersaturation of constituents and drive precipitation reactions. Magnetic resonance imaging (MRI) and micro-computed tomography (µ-CT) were employed as complimentary techniques to evaluate advection, dispersion and formation of precipitate in a 3D porous media flow cell. Two parallel fluids were flowed concentrically through the porous media under two flow rate conditions with Na2CO3 and CaCl2 in the inner and outer fluids, respectively. Upon mixing, calciummore » carbonate became supersaturated and formed a precipitate at the interface of the two fluids. Spatial maps of changing local velocity fields and dispersion in the flow cell were generated from MRI, while high resolution imaging of the precipitate formed in the porous media was achieved via µ-CT imaging. Formation of a precipitate layer minimized dispersive and advective transport between the two fluids and the shape of the precipitation was influenced by the flow rate condition.« less

  2. Impact of mineral precipitation on flow and mixing in porous media determined by microcomputed tomography and MRI

    SciTech Connect

    Bray, Joshua M.; Lauchnor, Ellen G.; Redden, George D.; Gerlach, Robin; Fujita, Yoshiko; Codd, Sarah L.; Seymour, Joseph D.

    2016-12-21

    Here, precipitation reactions in porous media influence transport properties of the environment and can control advective and dispersive transport. In subsurface environments, mixing of saline groundwater or injected solutions for remediation with fresh groundwater can induce supersaturation of constituents and drive precipitation reactions. Magnetic resonance imaging (MRI) and micro-computed tomography (µ-CT) were employed as complimentary techniques to evaluate advection, dispersion and formation of precipitate in a 3D porous media flow cell. Two parallel fluids were flowed concentrically through the porous media under two flow rate conditions with Na2CO3 and CaCl2 in the inner and outer fluids, respectively. Upon mixing, calcium carbonate became supersaturated and formed a precipitate at the interface of the two fluids. Spatial maps of changing local velocity fields and dispersion in the flow cell were generated from MRI, while high resolution imaging of the precipitate formed in the porous media was achieved via µ-CT imaging. Formation of a precipitate layer minimized dispersive and advective transport between the two fluids and the shape of the precipitation was influenced by the flow rate condition.

  3. Contrast enhanced micro-computed tomography resolves the 3-dimensional morphology of the cardiac conduction system in mammalian hearts.

    PubMed

    Stephenson, Robert S; Boyett, Mark R; Hart, George; Nikolaidou, Theodora; Cai, Xue; Corno, Antonio F; Alphonso, Nelson; Jeffery, Nathan; Jarvis, Jonathan C

    2012-01-01

    The general anatomy of the cardiac conduction system (CCS) has been known for 100 years, but its complex and irregular three-dimensional (3D) geometry is not so well understood. This is largely because the conducting tissue is not distinct from the surrounding tissue by dissection. The best descriptions of its anatomy come from studies based on serial sectioning of samples taken from the appropriate areas of the heart. Low X-ray attenuation has formerly ruled out micro-computed tomography (micro-CT) as a modality to resolve internal structures of soft tissue, but incorporation of iodine, which has a high molecular weight, into those tissues enhances the differential attenuation of X-rays and allows visualisation of fine detail in embryos and skeletal muscle. Here, with the use of a iodine based contrast agent (I(2)KI), we present contrast enhanced micro-CT images of cardiac tissue from rat and rabbit in which the three major subdivisions of the CCS can be differentiated from the surrounding contractile myocardium and visualised in 3D. Structures identified include the sinoatrial node (SAN) and the atrioventricular conduction axis: the penetrating bundle, His bundle, the bundle branches and the Purkinje network. Although the current findings are consistent with existing anatomical representations, the representations shown here offer superior resolution and are the first 3D representations of the CCS within a single intact mammalian heart.

  4. Virtual forensic entomology: improving estimates of minimum post-mortem interval with 3D micro-computed tomography.

    PubMed

    Richards, Cameron S; Simonsen, Thomas J; Abel, Richard L; Hall, Martin J R; Schwyn, Daniel A; Wicklein, Martina

    2012-07-10

    We demonstrate how micro-computed tomography (micro-CT) can be a powerful tool for describing internal and external morphological changes in Calliphora vicina (Diptera: Calliphoridae) during metamorphosis. Pupae were sampled during the 1st, 2nd, 3rd and 4th quarter of development after the onset of pupariation at 23 °C, and placed directly into 80% ethanol for preservation. In order to find the optimal contrast, four batches of pupae were treated differently: batch one was stained in 0.5M aqueous iodine for 1 day; two for 7 days; three was tagged with a radiopaque dye; four was left unstained (control). Pupae stained for 7d in iodine resulted in the best contrast micro-CT scans. The scans were of sufficiently high spatial resolution (17.2 μm) to visualise the internal morphology of developing pharate adults at all four ages. A combination of external and internal morphological characters was shown to have the potential to estimate the age of blowfly pupae with a higher degree of accuracy and precision than using external morphological characters alone. Age specific developmental characters are described. The technique could be used as a measure to estimate a minimum post-mortem interval in cases of suspicious death where pupae are the oldest stages of insect evidence collected.

  5. Micro-Computed Tomography Detection of Gold Nanoparticle-Labelled Mesenchymal Stem Cells in the Rat Subretinal Layer.

    PubMed

    Mok, Pooi Ling; Leow, Sue Ngein; Koh, Avin Ee-Hwan; Mohd Nizam, Hairul Harun; Ding, Suet Lee Shirley; Luu, Chi; Ruhaslizan, Raduan; Wong, Hon Seng; Halim, Wan Haslina Wan Abdul; Ng, Min Hwei; Idrus, Ruszymah Binti Hj; Chowdhury, Shiplu Roy; Bastion, Catherine Mae-Lynn; Subbiah, Suresh Kumar; Higuchi, Akon; Alarfaj, Abdullah A; Then, Kong Yong

    2017-02-08

    Mesenchymal stem cells are widely used in many pre-clinical and clinical settings. Despite advances in molecular technology; the migration and homing activities of these cells in in vivo systems are not well understood. Labelling mesenchymal stem cells with gold nanoparticles has no cytotoxic effect and may offer suitable indications for stem cell tracking. Here, we report a simple protocol to label mesenchymal stem cells using 80 nm gold nanoparticles. Once the cells and particles were incubated together for 24 h, the labelled products were injected into the rat subretinal layer. Micro-computed tomography was then conducted on the 15th and 30th day post-injection to track the movement of these cells, as visualized by an area of hyperdensity from the coronal section images of the rat head. In addition, we confirmed the cellular uptake of the gold nanoparticles by the mesenchymal stem cells using transmission electron microscopy. As opposed to other methods, the current protocol provides a simple, less labour-intensive and more efficient labelling mechanism for real-time cell tracking. Finally, we discuss the potential manipulations of gold nanoparticles in stem cells for cell replacement and cancer therapy in ocular disorders or diseases.

  6. Efficacy of different solvents in removing gutta-percha from curved root canals: a micro-computed tomography study.

    PubMed

    Sağlam, Baran Can; Koçak, Mustafa Murat; Türker, Sevinç Aktemur; Koçak, Sibel

    2014-08-01

    The aim of this study was to compare the root filling material that remained after retreatment of curved root canals with chloroform and Endosolv R as solvents. The evaluation employed micro-computed tomography (CT) imaging. Thirty-six extracted molar teeth with curved roots were selected. After preparation with ProTaper rotary instruments, the canals were filled with gutta-percha and AH26 sealer. The teeth were randomly divided into three groups according to solvent used (n = 12) as follows: group 1: chloroform; group 2: Endosolv R; group 3: no solvent (negative control). ProTaper Universal Retreatment files were used to remove each root canal filling and then the self-adjusting file was applied for two minutes. Preoperative and postoperative micro-CT images were used to assess the percentage of residual filling material. The mean percentage of residual filling material was quantified. There were no statistically significant differences between the groups in terms of percentage volume of residual root canal filling.

  7. Feasibility and safety of silicone rubber contrast-enhanced microcomputed tomography in evaluating the angioarchitecture of prostatectomy specimens.

    PubMed

    Yeung, Alex K; Atri, Mostafa; Sugar, Linda; Klotz, Laurence

    2011-06-01

    This ethics committee-approved pilot study was carried out with informed consent. A protocol was developed to assess the feasibility of in vitro Microfil injection of prostate cancer specimens followed by analysis with micro-computed tomography (microCT) to characterize the functional vascularity of prostatic tissue and evaluate its safety with respect to the preservation of a specimen for pathologic examination. The visible prostatic arteries of two surgically resected prostates frompatients with known prostate cancer (PCa) were injected with MicrofilMV-122 contrast medium immediately after removal. The specimens were scanned using microCT and were qualitatively examined using three-dimensional analysis software (MicroView; GE Healthcare Biosciences). The Microfil perfusion in the two samples was sufficient to view the functional vascularity arising from a major prostatic artery, up to a resolution of 17.626 µm without any indication of adverse effects due to Microfil injection. Malignant prostatic regions showed a greater vascular density on histology but decreased vascular perfusion compared with benign prostatic regions. The use of microCT on Microfil-injected prostates seems to be a feasible and specimen-preserving method for visualizing the three-dimensional vessel patterns present in resected human prostates.

  8. 3D mapping of polymerization shrinkage using X-ray micro-computed tomography to predict microleakage.

    PubMed

    Sun, Jirun; Eidelman, Naomi; Lin-Gibson, Sheng

    2009-03-01

    The objectives of this study were to (1) demonstrate X-ray micro-computed tomography (microCT) as a viable method for determining the polymerization shrinkage and microleakage on the same sample accurately and non-destructively, and (2) investigate the effect of sample geometry (e.g., C-factor and volume) on polymerization shrinkage and microleakage. Composites placed in a series of model cavities of controlled C-factors and volumes were imaged using microCT to determine their precise location and volume before and after photopolymerization. Shrinkage was calculated by comparing the volume of composites before and after polymerization and leakage was predicted based on gap formation between composites and cavity walls as a function of position. Dye penetration experiments were used to validate microCT results. The degree of conversion (DC) of composites measured using FTIR microspectroscopy in reflectance mode was nearly identical for composites filled in all model cavity geometries. The shrinkage of composites calculated based on microCT results was statistically identical regardless of sample geometry. Microleakage, on the other hand, was highly dependent on the C-factor as well as the composite volume, with higher C-factors and larger volumes leading to a greater probability of microleakage. Spatial distribution of microleakage determined by microCT agreed well with results determined by dye penetration. microCT has proven to be a powerful technique in quantifying polymerization shrinkage and corresponding microleakage for clinically relevant cavity geometries.

  9. Observation of the dissolution process of Globigerina bulloides tests (planktic foraminifera) by X-ray microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Iwasaki, Shinya; Kimoto, Katsunori; Sasaki, Osamu; Kano, Harumasa; Honda, Makio C.; Okazaki, Yusuke

    2015-04-01

    We performed a 9 day dissolution experiment with tests of the planktic foraminifer Globigerina bulloides at pH 6.7 ± 0.1 in water undersaturated with respect to calcite. The initial stage of the dissolution process, which is not recognizable from the surface structure of the tests, was quantitatively evaluated by X-ray microcomputed tomography (XMCT). XMCT revealed three distinct test structures: early-developed calcite formed during the juvenile stage of G. bulloides, an inner calcite layer, and an outer calcite layer. The test ultrastructure was observed by scanning electron microscopy, and CT number evaluated the density distribution in the test. The early-developed calcite and inner calcite layer had low CT numbers (500-1300; low density, porous) and were sensitive to dissolution, whereas the outer calcite layer had high CT numbers (<1300 high density) and resisted dissolution. Both the modes and the frequencies of the CT numbers decreased with progress of dissolution. Changes in the CT number histogram with progress of dissolution were quantified in terms of the percentage of calcite volume accounted for by low-density calcite (% Low-CT-number calcite). A clear linear relationship (R2 = 0.87) between % Low-CT-number calcite and % Test weight loss was found. This relationship indicates that the amount of test dissolution can be estimated from the distribution of CT numbers. We propose that XMCT measurements will be useful for quantitatively estimating the amount of carbonate loss from foraminiferal tests by dissolution.

  10. Analysis of maize ( Zea mays ) kernel density and volume using microcomputed tomography and single-kernel near-infrared spectroscopy.

    PubMed

    Gustin, Jeffery L; Jackson, Sean; Williams, Chekeria; Patel, Anokhee; Armstrong, Paul; Peter, Gary F; Settles, A Mark

    2013-11-20

    Maize kernel density affects milling quality of the grain. Kernel density of bulk samples can be predicted by near-infrared reflectance (NIR) spectroscopy, but no accurate method to measure individual kernel density has been reported. This study demonstrates that individual kernel density and volume are accurately measured using X-ray microcomputed tomography (μCT). Kernel density was significantly correlated with kernel volume, air space within the kernel, and protein content. Embryo density and volume did not influence overall kernel density. Partial least-squares (PLS) regression of μCT traits with single-kernel NIR spectra gave stable predictive models for kernel density (R(2) = 0.78, SEP = 0.034 g/cm(3)) and volume (R(2) = 0.86, SEP = 2.88 cm(3)). Density and volume predictions were accurate for data collected over 10 months based on kernel weights calculated from predicted density and volume (R(2) = 0.83, SEP = 24.78 mg). Kernel density was significantly correlated with bulk test weight (r = 0.80), suggesting that selection of dense kernels can translate to improved agronomic performance.

  11. Phase-Contrast Micro-Computed Tomography Measurements of the Intraocular Pressure-Induced Deformation of the Porcine Lamina Cribrosa.

    PubMed

    Coudrillier, Baptiste; Geraldes, Diogo M; Vo, Nghia T; Atwood, Robert; Reinhard, Christina; Campbell, Ian C; Raji, Yazdan; Albon, Julie; Abel, Richard L; Ethier, C Ross

    2016-04-01

    The lamina cribrosa (LC) is a complex mesh-like tissue in the posterior eye. Its biomechanical environment is thought to play a major role in glaucoma, the second most common cause of blindness. Due to its small size and relative inaccessibility, high-resolution measurements of LC deformation, important in characterizing LC biomechanics, are challenging. Here we present a novel noninvasive imaging method, which enables measurement of the three-dimensional deformation of the LC caused by acute elevation of intraocular pressure (IOP). Posterior segments of porcine eyes were imaged using synchrotron radiation phase contrast micro-computed tomography (PC μCT) at IOPs between 6 and 37 mmHg. The complex trabecular architecture of the LC was reconstructed with an isotropic spatial resolution of 3.2 μm. Scans acquired at different IOPs were analyzed with digital volume correlation (DVC) to compute full-field deformation within the LC. IOP elevation caused substantial tensile, shearing and compressive devformation within the LC, with maximum tensile strains at 30 mmHg averaging 5.5%, and compressive strains reaching 20%. We conclude that PC μCT provides a novel high-resolution method for imaging the LC, and when combined with DVC, allows for full-field 3D measurement of ex vivo LC biomechanics at high spatial resolution.

  12. Phase-contrast Micro-computed Tomography Measurements of the Intraocular Pressure-induced Deformation of the Porcine Lamina Cribrosa.

    PubMed

    Coudrillier, Baptiste; Geraldes, Diogo; Vo, Nghia; Atwood, Robert; Reinhard, Christina; Campbell, Ian; Raji, Yazdan; Albon, Julie; Abel, Richard; Ethier, Ross

    2015-11-30

    The lamina cribrosa (LC) is a complex mesh-like tissue in the posterior eye. Its biomechanical environment is thought to play a major role in glaucoma, the second most common cause of blindness. Due to its small size and relative inaccessibility, highresolution measurements of LC deformation, important in characterizing LC biomechanics, are challenging. Here we present a novel noninvasive imaging method, which enables measurement of the three-dimensional deformation of the LC caused by acute elevation of intraocular pressure (IOP). Posterior segments of porcine eyes were imaged using synchrotron radiation phase contrast micro-computed tomography (PC CT) at IOPs between 6 and 37mmHg. The complex trabecular architecture of the LC was reconstructed with an isotropic spatial resolution of 3.2 m. Scans acquired at different IOPs were analyzed with digital volume correlation (DVC) to compute full-field deformation within the LC. IOP elevation caused substantial tensile, shearing and compressive deformation within the LC, with maximum tensile strains at 30mmHg averaging 5.5%, and compressive strains reaching 20%. We conclude that PC CT provides a novel high-resolution method for imaging the LC, and when combined with DVC, allows for full-field 3D measurement of ex vivo LC biomechanics at high spatial resolution.

  13. A Novel Model for Evaluating the Flow of Endodontic Materials Using Micro-computed Tomography.

    PubMed

    Tanomaru-Filho, Mario; Torres, Fernanda Ferrari Esteves; Bosso-Martelo, Roberta; Chávez-Andrade, Gisselle Moraima; Bonetti-Filho, Idomeo; Guerreiro-Tanomaru, Juliane Maria

    2017-05-01

    Flow and filling ability are important properties of endodontic materials. The aim of this study was to propose a new technique for evaluating flow using micro-computed tomographic (μCT) imaging. A glass plate was manufactured with a central cavity and 4 grooves extending out horizontally and vertically. The flow of MTA-Angelus (Angelus, Londrina, PR, Brazil), zinc oxide eugenol (ZOE), and Biodentine (BIO) (Septodont, Saint Maur des Fossés, France) was evaluated using International Standards Organization (ISO) 6876/2002 and a new technique as follows: 0.05 ± 0.005 mL of each material was placed in the central cavity, and another glass plate and metal weight with a total mass of 120 g were placed over the material. The plate/material set was scanned using μCT imaging. The flow was calculated by linear measurement (mm) of the material in the grooves. Central cavity filling was calculated in mm(3) in the central cavity. Lateral cavity filling (LCF) was measured by LCF mean values up to 2 mm from the central cavity. Data were analyzed statistically using analysis of variance and Tukey tests with a 5% significance level. ZOE showed the highest flow rate determined by ISO methodology (P < .05). Analysis performed using μCT imaging showed MTA-Angelus and ZOE had higher linear flow rates in the grooves. Central cavity filling was similar for the materials. However, LCF was higher for BIO versus ZOE. Although ZOE presented better flow determined by ISO methodology, BIO showed the best filling ability. The model of the technique proposed for evaluating flow using μCT imaging showed proper and reproducible results and could improve flow analysis. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Imaging and quantitative assessment of long bone vascularization in the adult rat using microcomputed tomography.

    PubMed

    Fei, Jia; Jia, Fei; Peyrin, Françoise; Françoise, Peyrin; Malaval, Luc; Vico, Laurence; Laurence, Vico; Lafage-Proust, Marie-Hélène; Marie-Hélène, Lafage-Proust

    2010-02-01

    The objective of this study was to develop and validate a technique for both 3D imaging and quantification of the vascular network of bone tissue in the rat. Five month-old male Wistar rats were divided into tail-suspension (21 days) and control groups. Sixty percent barium sulfate solution was infused into the vena cava. The tibiae were evaluated in 2D and 3D before and after decalcification, using conventional microcomputerized tomography (muCT) at 10 and 5 mum resolution and synchrotron radiation (SR) muCT. The perfusion technique and tomography exhibited excellent bone vasculature imaging. Significant positive correlations were observed between 2D histomorphometric and 3D muCT vascular parameters (P < 0.05). 3DmuCT discriminated significant changes of vessel structures in unloading condition: vessel number decreased by 25%, (P < 0.005), vessel separation increased by 27%, P < 0.01. SRmuCT could image sinusoid clusters in bone. muCT is an accurate and reproducible technique for 3D quantitative evaluation of long bone vascularisation in the rat. 2009 Wiley-Liss, Inc.

  15. The root canal morphology in mandibular first premolars: a comparative evaluation of cone-beam computed tomography and micro-computed tomography.

    PubMed

    Zhang, Dan; Chen, Junhong; Lan, Guihua; Li, Min; An, Jianping; Wen, Xiujie; Liu, Luchuan; Deng, Manjing

    2017-05-01

    This study evaluated the accuracy of cone-beam computed tomography (CBCT) in detecting the root canal morphology of mandibular first premolars using micro-computed tomography (micro-CT) as a reference standard. In total, 143 extracted human mandibular first premolars were selected and scanned using micro-CT and CBCT. The acquired images were used to evaluate the root canal morphology in each tooth, and evaluations were repeated after 2 weeks. The root canal configurations observed on the three-dimensional images were recorded, and the findings from both modalities were compared using chi-square tests. The actual agreement between the two modalities was assessed using kappa statistics. In total, the root morphologies in 136 mandibular first premolars were consistently identified by both CBCT and micro-CT: type I in 104, type III in five, type V in 20, and type IX in seven. Of the remaining seven teeth, the morphology in two, one, and four teeth was identified as type I, type VII, and type IX (type 1-3 in two and type 1-2-3 in two), respectively, by micro-CT and misdiagnosed as type III, type V, and type V, respectively, by CBCT. There were no significant differences between the two modalities with regard to the accurate detection of root canal configurations, with a kappa value of 0.886 for the actual agreement. Although CBCT may be accurate in detecting the root canal configuration in mandibular first premolars, it produces poorer image details compared with micro-CT. CBCT is a reliable radiological technique, but its accuracy in detecting details of the root canal morphology in mandibular first premolars, especially in some complex root canal configurations, needs to be improved.

  16. Laboratory x-ray micro-computed tomography: a user guideline for biological samples

    PubMed Central

    2017-01-01

    Abstract Laboratory x-ray micro–computed tomography (micro-CT) is a fast-growing method in scientific research applications that allows for non-destructive imaging of morphological structures. This paper provides an easily operated “how to” guide for new potential users and describes the various steps required for successful planning of research projects that involve micro-CT. Background information on micro-CT is provided, followed by relevant setup, scanning, reconstructing, and visualization methods and considerations. Throughout the guide, a Jackson's chameleon specimen, which was scanned at different settings, is used as an interactive example. The ultimate aim of this paper is make new users familiar with the concepts and applications of micro-CT in an attempt to promote its use in future scientific studies. PMID:28419369

  17. Investigation of rock samples using X-ray-microcomputer-tomography before and after mercury intrusion porosimetry

    SciTech Connect

    Klobes, P.; Riesemeier, H.; Meyer, K.; Goebbels, J.; Siitari-Kauppi, M.; Hellmuth, K.H.

    1997-12-31

    A new method for the physical characterization of rock matrices for use in site investigations of nuclear waste repositories has been developed. The method can provide information needed in the assessment of the performance of the geosphere working as a natural barrier retarding the migration of radionuclides by diffusion into the rock matrix. Most conventional methods for the physical characterization of rocks give only bulk information. The combination of mercury porosimetry and computer tomography can give 3-D data on mineral-specific porosity distributions with additional pore size information. Additionally, limits for mineral-specific internal surface areas can be estimated, which is essential for the assessment of water-rock interaction and reactive interaction with radionuclides (sorption). Results of measurements on granitic rock (granodiorite) from the Baltic shield are discussed and integrated with results by complementary methods.

  18. Characterization of the Distal Esophagus High-Pressure Zone with Manometry, Ultrasound and Micro-Computed Tomography

    PubMed Central

    Vegesna, Anil K.; Sloan, Joshua A.; Singh, Baltej; Phillips, Steven J; Braverman, Alan S.; Barbe, Mary F.; Ruggieri, Michael R.; Miller, Larry S.

    2012-01-01

    Background We sought to determine how the individual components of the distal esophagus and proximal stomach form the gastroesophageal junction high-pressure zone (GEJHPZ) anti-reflux barrier. Methods An endoscopic ultrasound/manometry catheter was pulled through the proximal stomach and distal esophagus in 20 normal subjects. The axial length and width of individual structures on endoscopic ultrasound were measured. The anatomic orientation of gastroesophageal junction (GEJ) components was examined in two organ donor specimens using micro-computed tomography (micro-CT). Key Results The three distinct structures identified within the GEJHPZ, from distal to proximal, were: the gastric clasp and sling muscle fiber complex, crural diaphragm, and lower esophageal circular smooth muscle fibers (LEC). The LEC was statistically significantly thicker than adjacent esophageal muscles. These structures were associated with 3 pressure peaks. The pressure peak produced by the clasp/sling fiber complex often overlapped with the pressure peak from the crural diaphragm. The most proximal peak, associated with the LEC, was significantly greater and bimodal in 9 of 20 subjects. This bimodal LEC pressure peak correlated with two areas of thickened muscle observed with ultrasound. Micro-CT of GEJ from organ donors confirmed the two areas of thickened muscle. Conclusions and inferences Three distinct anatomic structures, the clasp and sling muscle fibers, crural diaphragm, and LEC combine to form the anti-reflux barrier of the proximal stomach and distal esophagus. The clasp and sling muscle fibers combine with the crural diaphragm to form a distal pressure profile. The more proximal LEC has a bimodal pressure profile in some patients. PMID:22998376

  19. A novel approach for studying the temporal modulation of embryonic skeletal development using organotypic bone cultures and microcomputed tomography.

    PubMed

    Kanczler, Janos M; Smith, Emma L; Roberts, Carol A; Oreffo, Richard O C

    2012-10-01

    Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal

  20. Age estimation during the blow fly intra-puparial period: a qualitative and quantitative approach using micro-computed tomography.

    PubMed

    Martín-Vega, Daniel; Simonsen, Thomas J; Wicklein, Martina; Hall, Martin J R

    2017-05-04

    Minimum post-mortem interval (minPMI) estimates often rely on the use of developmental data from blow flies (Diptera: Calliphoridae), which are generally the first colonisers of cadavers and, therefore, exemplar forensic indicators. Developmental data of the intra-puparial period are of particular importance, as it can account for more than half of the developmental duration of the blow fly life cycle. During this period, the insect undergoes metamorphosis inside the opaque, barrel-shaped puparium, formed by the hardening and darkening of the third instar larval cuticle, which shows virtually no external changes until adult emergence. Regrettably, estimates based on the intra-puparial period are severely limited due to the lack of reliable, non-destructive ageing methods and are frequently based solely on qualitative developmental markers. In this study, we use non-destructive micro-computed tomography (micro-CT) for (i) performing qualitative and quantitative analyses of the morphological changes taking place during the intra-puparial period of two forensically relevant blow fly species, Calliphora vicina and Lucilia sericata, and (ii) developing a novel and reliable method for estimating insect age in forensic practice. We show that micro-CT provides age-diagnostic qualitative characters for most 10% time intervals of the total intra-puparial period, which can be used over a range of temperatures and with a resolution comparable to more invasive and time-consuming traditional imaging techniques. Moreover, micro-CT can be used to yield a quantitative measure of the development of selected organ systems to be used in combination with qualitative markers. Our results confirm micro-CT as an emerging, powerful tool in medico-legal investigations.

  1. Application of Micro-Computed Tomography with Iodine Staining to Cardiac Imaging, Segmentation and Computational Model Development

    PubMed Central

    Aslanidi, OV; Nikolaidou, T; Zhao, J; Smaill, BH; Gilbert, SH; Holden, AV; Lowe, T; Withers, PJ; Jarvis, JC; Stephenson, RS; Hart, G; Hancox, JC; Boyett, MR; Zhang, H

    2012-01-01

    Micro-computed tomography (micro-CT) has been widely used to generate high-resolution 3D tissue images from small animals non-destructively, especially for mineralized skeletal tissues. However, its application to the analysis of soft cardiovascular tissues has been limited by poor inter-tissue contrast. Recent ex vivo studies have shown that contrast between muscular and connective tissue in micro-CT images can be enhanced by staining with iodine. In the present study, we apply this novel technique for imaging of cardiovascular structures in canine hearts. We optimize the method to obtain high resolution X-ray micro-CT images of the canine atria and its distinctive regions - including the Bachmann’s bundle, atrioventricular node, pulmonary arteries and veins - with clear inter-tissue contrast. The imaging results are used to reconstruct and segment the detailed 3D geometry of the atria. Structure tensor analysis shows that the arrangement of atrial fibres can also be characterised using the enhanced micro-CT images, as iodine preferentially accumulates within the muscular fibres rather than in connective tissues. This novel technique can be particularly useful in non-destructive imaging of 3D cardiac architectures from large animals and humans, due to the combination of relatively high speed (~1 hour/scan of a large canine heart) and high voxel resolution (36 μm) provided. In summary, contrast micro-CT facilitates fast and non-destructive imaging and segmenting of detailed 3D cardiovascular geometries, as well as measuring fibre orientation, which are crucial in constructing biophysically detailed computational cardiac models. PMID:22829390

  2. Dentinal Microcrack Development after Canal Preparation: A Longitudinal in Situ Micro-computed Tomography Study Using a Cadaver Model.

    PubMed

    De-Deus, Gustavo; César de Azevedo Carvalhal, Júlio; Belladonna, Felipe Gonçalves; Silva, Emmanuel João Nogueira Leal; Lopes, Ricardo Tadeu; Moreira Filho, Renato Evando; Souza, Erick Miranda; Provenzano, José Claudio; Versiani, Marco Aurélio

    2017-09-01

    The purpose of this study was to evaluate the development of dentinal microcracks after root canal preparation with Reciproc and ProTaper Universal systems using an in situ cadaver model by means of a micro-computed tomography (micro-CT) imaging system. At autopsy, 8 maxillary bone blocks having at least the first and second premolar teeth (n = 16) were excised, scanned at a resolution of 13.18 μm, and randomly distributed into 2 groups (n = 8) according to the preparation protocol: Reciproc and ProTaper Universal systems. Root canals were prepared up to R25 and F2 instruments in the Reciproc and ProTaper Universal groups, respectively. After the preparation procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 19,060) were screened to identify the presence of dentinal defects. In the Reciproc group, 9176 cross-section images were analyzed, and no crack was observed. In the ProTaper Universal group, 244 of 9884 cross-section slices (2.46%) had dentinal defects; however, all defects were already present in the corresponding preoperative images, indicating that no new microcrack was created after canal preparation. In situ root canal preparation of maxillary premolars with Reciproc and ProTaper Universal systems did not induce the formation of dentinal microcracks in a cadaver model as observed by micro-CT. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. A micro-computed tomography study of the negotiation and anatomical feature in apical root canal of mandibular molars.

    PubMed

    Min, Yi; Ma, Jing-Zhi; Shen, Ya; Cheung, Gary Shun-Pan; Gao, Yuan

    2016-11-01

    The aim of this study was to investigate the clinical negotiation of various apical anatomic features of the mandibular first molars in a Chinese population using micro-computed tomography (micro-CT). A total of 152 mandibular first molars were scanned with micro-CT at 30 µm resolution. The apical 5 mm of root canal (ARC) was reconstructed three dimensionally and classified. Subsequently, the access cavity was prepared with the ARC anatomy blinded to the operator. The ARC was negotiated with a size 10 K file with or without precurve. Information on the ability to obtain a reproducible glide path was recorded. The anatomical classification of ARC was Type I with 68.45% in mandibular first molars. The negotiation result of ARC with Category i was 387 canals (74.00%). With a bent negotiating file, 96 canals were negotiated, including 88 reproducible glide paths (Category ii) and 8 irregular glide paths (Category iii). About 7.65% canals could not be negotiated with patency successfully (Category iv). The statistical analyze shown the anatomic feature of ARC had effect on the negotiation of ARC (p < 0.05). In conclusion, ARC anatomic variations had a strong potential impact on the negotiation. The category of negotiation in ARC would be helpful in the using of NiTi rotary instruments. Negotiation of ARC to the working length with patency should be careful and skillful because of the complexities of ARC. SCANNING 38:819-824, 2016. © 2016 Wiley Periodicals, Inc. © Wiley Periodicals, Inc.

  4. Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions.

    PubMed

    Waspe, Adam C; McErlain, David D; Pitelka, Vasek; Holdsworth, David W; Lacefield, James C; Fenster, Aaron

    2010-04-01

    Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 microm tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 microm, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154 +/- 113 microm. The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

  5. Integration and evaluation of a needle-positioning robot with volumetric microcomputed tomography image guidance for small animal stereotactic interventions

    SciTech Connect

    Waspe, Adam C.; McErlain, David D.; Pitelka, Vasek; Holdsworth, David W.; Lacefield, James C.; Fenster, Aaron

    2010-04-15

    Purpose: Preclinical research protocols often require insertion of needles to specific targets within small animal brains. To target biologically relevant locations in rodent brains more effectively, a robotic device has been developed that is capable of positioning a needle along oblique trajectories through a single burr hole in the skull under volumetric microcomputed tomography (micro-CT) guidance. Methods: An x-ray compatible stereotactic frame secures the head throughout the procedure using a bite bar, nose clamp, and ear bars. CT-to-robot registration enables structures identified in the image to be mapped to physical coordinates in the brain. Registration is accomplished by injecting a barium sulfate contrast agent as the robot withdraws the needle from predefined points in a phantom. Registration accuracy is affected by the robot-positioning error and is assessed by measuring the surface registration error for the fiducial and target needle tracks (FRE and TRE). This system was demonstrated in situ by injecting 200 {mu}m tungsten beads into rat brains along oblique trajectories through a single burr hole on the top of the skull under micro-CT image guidance. Postintervention micro-CT images of each skull were registered with preintervention high-field magnetic resonance images of the brain to infer the anatomical locations of the beads. Results: Registration using four fiducial needle tracks and one target track produced a FRE and a TRE of 96 and 210 {mu}m, respectively. Evaluation with tissue-mimicking gelatin phantoms showed that locations could be targeted with a mean error of 154{+-}113 {mu}m. Conclusions: The integration of a robotic needle-positioning device with volumetric micro-CT image guidance should increase the accuracy and reduce the invasiveness of stereotactic needle interventions in small animals.

  6. Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

    SciTech Connect

    Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

    2012-05-10

    The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

  7. Three-dimensional arrangement of β-tricalcium phosphate granules evaluated by microcomputed tomography and fractal analysis.

    PubMed

    Ndiaye, Mambaye; Terranova, Lisa; Mallet, Romain; Mabilleau, Guillaume; Chappard, Daniel

    2015-01-01

    The macrophysical properties of granular biomaterials used to fill bone defects have rarely been considered. Granules of a given biomaterial occupy three-dimensional (3-D) space when packed together and create a macroporosity suitable for the invasion of vascular and bone cells. Granules of β-tricalcium phosphate were prepared using polyurethane foam technology and increasing the amount of material powder in the slurry (10, 11, 15, 18, 21 and 25 g). After sintering, granules of 1000-2000 μm were prepared by sieving. They were analyzed morphologically by scanning electron microscopy and placed in polyethylene test tubes to produce 3-D scaffolds. Microcomputed tomography (microCT) was used to image the scaffolds and to determine porosity and fractal dimension in three dimensions. Two-dimensional sections of the microCT models were binarized and used to compute classical morphometric parameters describing porosity (interconnectivity index, strut analysis and star volumes) and fractal dimensions. In addition, two newly important fractal parameters (lacunarity and succolarity) were measured. Compression analysis of the stacks of granules was done. Porosity decreased as the amount of material in the slurry increased but non-linear relationships were observed between microarchitectural parameters describing the pores and porosity. Lacunarity increased in the series of granules but succolarity (reflecting the penetration of a fluid) was maximal in the 15-18 g groups and decreased noticeably in the 25 g group. The 3-D arrangement of biomaterial granules studied by these new fractal techniques allows the optimal formulation to be derived based on the lowest amount of material, suitable mechanical resistance during crushing and the creation of large interconnected pores.

  8. Magnetic Resonance Imaging and Micro-Computed Tomography Combined Atlas of Developing and Adult Mouse Brains for Stereotaxic Surgery

    PubMed Central

    Aggarwal, Manisha; Zhang, Jiangyang; Miller, Michael I.; Sidman, Richard L.; Mori, Susumu

    2009-01-01

    Stereotaxic atlases of the mouse brain are important in neuroscience research for targeting of specific internal brain structures during surgical operations. The effectiveness of stereotaxic surgery depends on accurate mapping of the brain structures relative to landmarks on the skull. During postnatal development in the mouse, rapid growth-related changes in the brain occur concurrently with growth of bony plates at the cranial sutures, therefore adult mouse brain atlases cannot be used to precisely guide stereotaxis in developing brains. In this study, three-dimensional stereotaxic atlases of C57BL/6J mouse brains at six postnatal developmental stages: P7, P14, P21, P28, P63 and in adults (P140–P160) were developed, using diffusion tensor imaging (DTI) and micro-computed tomography (CT). At present, most widely-used stereotaxic atlases of the mouse brain are based on histology, but the anatomical fidelity of ex vivo atlases to in vivo mouse brains has not been evaluated previously. To account for ex vivo tissue distortion due to fixation as well as individual variability in the brain, we developed a population-averaged in vivo MRI adult mouse brain stereotaxic atlas, and a distortion-corrected DTI atlas was generated by nonlinearly warping ex vivo data to the population-averaged in vivo atlas. These atlas resources were developed and made available through a new software user-interface with the objective of improving the accuracy of targeting brain structures during stereotaxic surgery in developing and adult C57BL/6J mouse brains. PMID:19490934

  9. Prediction of primary breast cancer size and T-stage using micro-computed tomography in lumpectomy specimens.

    PubMed

    Sarraj, Wafa M; Tang, Rong; Najjar, Anas L; Griffin, Molly; Bui, Anthony H; Zambeli-Ljepovic, Alan; Senter-Zapata, Mike; Lewin-Berlin, Maya; Fernandez, Leopoldo; Buckley, Juliette; Ly, Amy; Brachtel, Elena; Aftreth, Owen; Gilbertson, John; Yagi, Yukako; Gadd, Michele; Hughes, Kevin S; Smith, Barbara L; Michaelson, James S

    2015-01-01

    Histopathology is the only accepted method to measure and stage the breast tumor size. However, there is a need to find another method to measure and stage the tumor size when the pathological assessment is not available. Micro-computed tomography. (micro-CT) has the ability to measure tumor in three dimensions in an intact lumpectomy specimen. In this study, we aimed to determine the accuracy of micro-CT to measure and stage the primary tumor size in breast lumpectomy specimens, as compared to the histopathology. Seventy-two women who underwent lumpectomy surgery at the Massachusetts General Hospital Department of Surgery from June 2011 to September 2011, and from August 2013 to December 2013 participated in this study. The lumpectomy specimens were scanned using micro-CT followed by routine pathological processing. The maximum dimension of the invasive breast tumor was obtained from the micro-CT image and was compared to the corresponding pathology report for each subject. The invasive tumor size measurement by micro-CT was underestimated in 24 cases. (33%), overestimated in 37 cases. (51%), and matched it exactly in 11 cases. (15%) compared to the histopathology measurement for all the cases. However, micro-CT T-stage classification differed from histopathology in only 11. (15.2%) with 6 cases. (8.3%) classified as a higher stage by micro-CT, and 5 cases. (6.9%) classified as lower compared to histopathology. In addition, micro-CT demonstrated a statically significant strong agreement (κ =0.6, P < 0.05) with pathological tumor size and staging for invasive ductal carcinoma. (IDC) group. In contrast, there was no agreement. (κ = -2, P = 0.67) between micro-CT and pathology in estimating and staging tumor size for invasive lobular carcinoma. (ILC) group. This could be explained by a small sample size. (7) for ILC group. Micro-CT is a promising modality for measuring and staging the IDC.

  10. Micro-computed tomography in murine models of cerebral cavernous malformations as a paradigm for brain disease.

    PubMed

    Girard, Romuald; Zeineddine, Hussein A; Orsbon, Courtney; Tan, Huan; Moore, Thomas; Hobson, Nick; Shenkar, Robert; Lightle, Rhonda; Shi, Changbin; Fam, Maged D; Cao, Ying; Shen, Le; Neander, April I; Rorrer, Autumn; Gallione, Carol; Tang, Alan T; Kahn, Mark L; Marchuk, Douglas A; Luo, Zhe-Xi; Awad, Issam A

    2016-09-15

    Cerebral cavernous malformations (CCMs) are hemorrhagic brain lesions, where murine models allow major mechanistic discoveries, ushering genetic manipulations and preclinical assessment of therapies. Histology for lesion counting and morphometry is essential yet tedious and time consuming. We herein describe the application and validations of X-ray micro-computed tomography (micro-CT), a non-destructive technique allowing three-dimensional CCM lesion count and volumetric measurements, in transgenic murine brains. We hereby describe a new contrast soaking technique not previously applied to murine models of CCM disease. Volumetric segmentation and image processing paradigm allowed for histologic correlations and quantitative validations not previously reported with the micro-CT technique in brain vascular disease. Twenty-two hyper-dense areas on micro-CT images, identified as CCM lesions, were matched by histology. The inter-rater reliability analysis showed strong consistency in the CCM lesion identification and staging (K=0.89, p<0.0001) between the two techniques. Micro-CT revealed a 29% greater CCM lesion detection efficiency, and 80% improved time efficiency. Serial integrated lesional area by histology showed a strong positive correlation with micro-CT estimated volume (r(2)=0.84, p<0.0001). Micro-CT allows high throughput assessment of lesion count and volume in pre-clinical murine models of CCM. This approach complements histology with improved accuracy and efficiency, and can be applied for lesion burden assessment in other brain diseases. Copyright © 2016 Elsevier B.V. All rights reserved.

  11. Effect of micro-computed tomography voxel size and segmentation method on trabecular bone microstructure measures in mice.

    PubMed

    Christiansen, Blaine A

    2016-12-01

    Micro-computed tomography (μCT) is currently the gold standard for determining trabecular bone microstructure in small animal models. Numerous parameters associated with scanning and evaluation of μCT scans can strongly affect morphologic results obtained from bone samples. However, the effect of these parameters on specific trabecular bone outcomes is not well understood. This study investigated the effect of μCT scanning with nominal voxel sizes between 6-30 μm on trabecular bone outcomes quantified in mouse vertebral body trabecular bone. Additionally, two methods for determining a global segmentation threshold were compared: based on qualitative assessment of 2D images, or based on quantitative assessment of image histograms. It was found that nominal voxel size had a strong effect on several commonly reported trabecular bone parameters, in particular connectivity density, trabecular thickness, and bone tissue mineral density. Additionally, the two segmentation methods provided similar trabecular bone outcomes for scans with small nominal voxel sizes, but considerably different outcomes for scans with larger voxel sizes. The Qualitatively Selected segmentation method more consistently estimated trabecular bone volume fraction (BV/TV) and trabecular thickness across different voxel sizes, but the Histogram segmentation method more consistently estimated trabecular number, trabecular separation, and structure model index. Altogether, these results suggest that high-resolution scans be used whenever possible to provide the most accurate estimation of trabecular bone microstructure, and that the limitations of accurately determining trabecular bone outcomes should be considered when selecting scan parameters and making conclusions about inter-group variance or between-group differences in studies of trabecular bone microstructure in small animals.

  12. Micro-computed tomography scan and virtual histological slide data for the land planarian Obama otavioi (Platyhelminthes).

    PubMed

    Carbayo, Fernando; Lenihan, Jennifer Winifred

    2016-01-01

    We investigated whether images obtained through X-ray micro-computed tomography (μCT) can be used in conjunction with traditional methods for morphological studies of soft-bodied land planarians. μCT is non-invasive and provides true-to-scale three-dimensional imagery at high resolution. We compared μCT-based images of a recently described land planarian species of Obama otavioi (Platyhelminthes) with those obtained from light microphotography of histological sections, most of which were also digitized at high magnification. The specimens studied were collected in 2012. Subsequent μCT-based images of the stained body of a paratype show nearly all morphological features provided by traditional histology, with the exception of particularly minute structures, smaller than 5 μm, such as the sensory pits and single muscle fibers, which are best visible on traditional histological sections. Because the technique is non-destructive, the scanned specimen is preserved without damage. The raw and derivative μCT data and virtual histological sections are freely available in GigaDB. The μCT datasets of these stained soft-bodied organisms reveal images of external and internal structures that support previous taxonomic studies. This technique can be particularly important for non-destructively revealing internal details of whole museum specimens at a faster rate than histology alone. High-resolution virtual histological slides also allow further searches for new, previously unstudied morphological features. The use of X-ray equipment with higher resolution can enable smaller sensory organ and muscle fiber details to be seen. The image sets, μCT-based images and digitized histological slides can be disseminated without the constraints of specimen loans.

  13. Comparing canal transportation and centering ability of endosequence and vortex rotary files by using micro-computed tomography.

    PubMed

    Yamamura, Brandon; Cox, Timothy C; Heddaya, Belal; Flake, Natasha M; Johnson, James D; Paranjpe, Avina

    2012-08-01

    EndoSequence and Vortex are 2 recently developed rotary file systems that are made with traditional nickel-titanium (NiTi) and M-Wire technology, respectively. Previous studies have demonstrated better fatigue resistance of M-Wire rotary files compared with the conventional NiTi file. However, no study has compared the effects of M-Wire and conventional NiTi on transportation and centering ability. Hence, the aim of this study was to evaluate the transportation and centering ability of EndoSequence and Vortex files in mesial roots of mandibular molars by using micro-computed tomography imaging. Sixteen extracted mandibular molars with mesiobuccal and mesiolingual canals with separate foramina were used. Preinstrumentation scans of all teeth were taken, and the teeth were divided into 2 groups. In group 1, the mesiobuccal canals were instrumented with Vortex files and the mesiolingual canals with EndoSequence files. In group 2, the mesiobuccal canals were instrumented with EndoSequence files and the mesiolingual canals with Vortex files. Two file sizes were compared, 30/.04 and 40/.04. Postinstrumentation scans were performed, and the 2 scans were compared to determine centering ability and transportation. The amount of transportation at 1, 3, and 5 mm was similar for both file types in both file sizes. Transportation toward the furcation area at 7 mm was greater with the 30/.04 Endosequence files compared with the Vortex 30/.04 files (P < .05), but there was no difference in size 40/.04 files. Overall, our study does not support the use of one rotary file system over the other (Vortex or EndoSequence) when comparing transportation and centering ability. Published by Elsevier Inc.

  14. Using Micro-Computed Tomography to Evaluate the Dynamics of Orthodontically Induced Root Resorption Repair in a Rat Model

    PubMed Central

    Yang, Fengxue; Wei, Shicheng; Dai, Hongwei

    2016-01-01

    Objective To observe dynamic changes in root resorption repair, tooth movement relapse and alveolar bone microstructure following the application of orthodontic force. Materials and Methods Forces of 20 g, 50 g or 100 g were delivered to the left maxillary first molars of fifteen 10-week-old rats for 14 days. Each rat was subjected to micro-computed tomography scanning at 0, 3, 7, 10, 14, 28 and 42 days after force removal. The root resorption crater volume, tooth movement relapse and alveolar bone microarchitecture were measured at each time point. Results From day 3 to day 14, the root resorption volume decreased significantly in each group. In the 20-g force group, the root resorption volume gradually stabilized after 14 days, whereas in the 50-g and 100-g force groups, it stabilized after 28 days. In all groups, tooth movement relapsed significantly from day 0 to day 14 and then remained stable. From day 3 to day 10, the 20-g group exhibited faster relapse than the 50-g and 100-g groups. In all groups, the structure model index and trabecular separation decreased slowly from day 0 to day 10 and eventually stabilized. Trabecular number increased slowly from day 0 to day 7 and then stabilized. Conclusions The initial stage of root resorption repair did not change significantly and was followed by a dramatic repair period before stabilizing. The most serious tooth movement relapse occurred immediately after the appliance was removed, and then the tooth completely returned to the original position. PMID:26930605

  15. A Novel Approach for Studying the Temporal Modulation of Embryonic Skeletal Development Using Organotypic Bone Cultures and Microcomputed Tomography

    PubMed Central

    Smith, Emma L.; Roberts, Carol A.

    2012-01-01

    Understanding the structural development of embryonic bone in a three dimensional framework is fundamental to developing new strategies for the recapitulation of bone tissue in latter life. We present an innovative combined approach of an organotypic embryonic femur culture model, microcomputed tomography (μCT) and immunohistochemistry to examine the development and modulation of the three dimensional structures of the developing embryonic femur. Isolated embryonic chick femurs were organotypic (air/liquid interface) cultured for 10 days in either basal, chondrogenic, or osteogenic supplemented culture conditions. The growth development and modulating effects of basal, chondrogenic, or osteogenic culture media of the embryonic chick femurs was investigated using μCT, immunohistochemistry, and histology. The growth and development of noncultured embryonic chick femur stages E10, E11, E12, E13, E15, and E17 were very closely correlated with increased morphometric indices of bone formation as determined by μCT. After 10 days in the organotpyic culture set up, the early aged femurs (E10 and E11) demonstrated a dramatic response to the chondrogenic or osteogenic culture conditions compared to the basal cultured femurs as determined by a change in μCT morphometric indices and modified expression of chondrogenic and osteogenic markers. Although the later aged femurs (E12 and E13) increased in size and structure after 10 days organotpypic culture, the effects of the osteogenic and chondrogenic organotypic cultures on these femurs were not significantly altered compared to basal conditions. We have demonstrated that the embryonic chick femur organotpyic culture model combined with the μCT and immunohistochemical analysis can provide an integral methodology for investigating the modulation of bone development in an ex vivo culture setting. Hence, these interdisciplinary techniques of μCT and whole organ bone cultures will enable us to delineate some of the temporal

  16. Classification and quantification of pore shapes in sandstone reservoir rocks with 3-D X-ray micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Schmitt, Mayka; Halisch, Matthias; Müller, Cornelia; Peres Fernandes, Celso

    2016-02-01

    Recent years have seen a growing interest in the characterization of the pore morphologies of reservoir rocks and how the spatial organization of pore traits affects the macro behavior of rock-fluid systems. With the availability of 3-D high-resolution imaging, such as x-ray micro-computed tomography (µ-CT), the detailed quantification of particle shapes has been facilitated by progress in computer science. Here, we show how the shapes of irregular rock particles (pores) can be classified and quantified based on binary 3-D images. The methodology requires the measurement of basic 3-D particle descriptors (length, width, and thickness) and a shape classification that involves the similarity of artificial objects, which is based on main pore network detachments and 3-D sample sizes. Two main pore components were identified from the analyzed volumes: pore networks and residual pore ganglia. A watershed algorithm was applied to preserve the pore morphology after separating the main pore networks, which is essential for the pore shape characterization. The results were validated for three sandstones (S1, S2, and S3) from distinct reservoirs, and most of the pore shapes were found to be plate- and cube-like, ranging from 39.49 to 50.94 % and from 58.80 to 45.18 % when the Feret caliper descriptor was investigated in a 10003 voxel volume. Furthermore, this study generalizes a practical way to correlate specific particle shapes, such as rods, blades, cuboids, plates, and cubes to characterize asymmetric particles of any material type with 3-D image analysis.

  17. Micro-Computed Tomography Analysis of the Root Canal Morphology of Palatal Roots of Maxillary First Molars.

    PubMed

    Marceliano-Alves, Marília; Alves, Flávio Rodrigues Ferreira; Mendes, Daniel de Melo; Provenzano, José Claudio

    2016-02-01

    A thorough knowledge of root canal anatomy is critical for successful root canal treatments. This study evaluated the internal anatomy of the palatal roots of maxillary first molars with micro-computed tomography (microCT). The palatal roots of extracted maxillary first molars (n = 169) were scanned with microCT to determine several anatomic parameters, including main canal classification, lateral canal occurrence and location, degree of curvature, main foramen position, apical constriction presence, diameters 1 and 2 mm from the apex and 1 mm from the foramen, minor dentin thickness in those regions, canal volume, surface area, and convexity. All canals were classified as Vertucci type I. The cross sections were oval in 61% of the canals. Lateral canals were found in 25% of the samples. The main foramen did not coincide with the root apex in 95% of the cases. Only 8% of the canals were classified as straight. Apical constriction was identified in 38% of the roots. The minor and major canal diameters and minor dentin thickness were decreased near the apex. The minor dentin thickness 1 mm from the foramen was 0.82 mm. The palatal canals exhibited a volume of 6.91 mm(3) and surface area of 55.31 mm(2) and were rod-shaped. The root canals of the palatal roots were classified as type I. However, some factors need to be considered during the treatment of these roots, including the frequent ocurrence of moderate/severe curvatures, oval-shaped cross-sections, and lateral canals, noncoincidence of the apical foramen with the root apex, and absence of apical constriction in most cases. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  18. Potential and limitations of X-Ray micro-computed tomography in arthropod neuroanatomy: A methodological and comparative survey

    PubMed Central

    Sombke, Andy; Lipke, Elisabeth; Michalik, Peter; Uhl, Gabriele; Harzsch, Steffen

    2015-01-01

    Classical histology or immunohistochemistry combined with fluorescence or confocal laser scanning microscopy are common techniques in arthropod neuroanatomy, and these methods often require time-consuming and difficult dissections and sample preparations. Moreover, these methods are prone to artifacts due to compression and distortion of tissues, which often result in information loss and especially affect the spatial relationships of the examined parts of the nervous system in their natural anatomical context. Noninvasive approaches such as X-ray micro-computed tomography (micro-CT) can overcome such limitations and have been shown to be a valuable tool for understanding and visualizing internal anatomy and structural complexity. Nevertheless, knowledge about the potential of this method for analyzing the anatomy and organization of nervous systems, especially of taxa with smaller body size (e.g., many arthropods), is limited. This study set out to analyze the brains of selected arthropods with micro-CT, and to compare these results with available histological and immunohistochemical data. Specifically, we explored the influence of different sample preparation procedures. Our study shows that micro-CT is highly suitable for analyzing arthropod neuroarchitecture in situ and allows specific neuropils to be distinguished within the brain to extract quantitative data such as neuropil volumes. Moreover, data acquisition is considerably faster compared with many classical histological techniques. Thus, we conclude that micro-CT is highly suitable for targeting neuroanatomy, as it reduces the risk of artifacts and is faster than classical techniques. J. Comp. Neurol. 523:1281–1295, 2015. © 2015 Wiley Periodicals, Inc. PMID:25728683

  19. Use of micro-computed tomography for the assessment of periapical lesions in small rodents: a systematic review.

    PubMed

    Kalatzis-Sousa, N G; Spin-Neto, R; Wenzel, A; Tanomaru-Filho, M; Faria, G

    2016-03-19

    This systematic review aimed to review the literature on the acquisition-, reconstruction-, and analysis parameters of micro-computed tomography (micro-CT) for the assessment of periapical lesions in rats and mice, and to illustrate the effect of variation in these parameters. The PubMed database was searched from 2000 to January 2015 (English-language publications) for reports on the use of micro-CT to evaluate periapical lesions in rats and mice. QUADAS criteria were used to rate the quality of the studies. To illustrate the effect of variations in acquisition-, reconstruction-, and analysis parameters on images of periapical lesions, micro-CT examination of two hemi-mandibles of mice, with periapical lesions around the first molar was undertaken. Twenty-one studies were identified, which analyzed periapical lesions in rats or mice using micro-CT. According to the QUADAS, no study was classified as high-, seven were classified as moderate-, and 14 as low quality. The effect of variation in parameters was that voxel size may interfere with image sharpness, reconstruction may interfere with image sharpness and contrast, and inadequate plane orientation may alter the size of the periapical lesion. Non-personalized ROIs resulted in areas that were not part of the periapical lesion. Changing the limits of the threshold for bone-tissue visualization increased lesion size. There is no defined protocol for acquiring and analyzing micro-CT images of periapical lesions in rats and mice. Further, acquisition-, reconstruction-, and analysis parameters are not adequately explained, which may compromise the scientific impact of the studies. This article is protected by copyright. All rights reserved.

  20. Evaluation of the marginal fit of full ceramic crowns by the microcomputed tomography (micro-CT) technique

    PubMed Central

    Demir, Necla; Ozturk, Atiye Nilgun; Malkoc, Meral Arslan

    2014-01-01

    Objective: To evaluate the marginal gap (MG) and absolute marginal discrepancy (MD) of full ceramic crowns with two finish line designs, shoulder and chamfer, using microcomputed tomography (micro-CT) before and after cementation. Materials and Methods: Sixty extracted human maxillary premolar teeth were divided into two groups based on the finish line design: Group I: 90° shoulder and Group II: 135° chamfer. The specimens were further grouped based on the type of full ceramic crown they received: Group A: Feldspathic Cerec inLab ceramic system, Group B: Cerec inLab aluminum oxide ceramic system and Group C: Lithium disilicate press ceramic system. Before cementation, five crowns from each group were scanned using micro-CT in two sections, sagittal and coronal, to determine the MG and MD values for four regions of the crown (sagittal buccal, sagittal lingual, coronal mesial and coronal distal). After cementation and thermal cycling, the scanning was repeated. Measurements were obtained from 10 points for each region, 80 points totally, to evaluate the MG and MD values. Files were processed using NRecon and CTAn software. Results were statistically analyzed using one- and two-way ANOVA and Tukey HSD tests (P = 0.05). Results: Full ceramic systems showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system generally presented the lowest variance, except in the MG values of the coronal mesial region. The MG and MD values of all ceramics increased significantly after cementation, except in the shoulder preparation design (sagittal buccal region) for MG and in the chamfer preparation design (sagittal lingual region) for MD values. Conclusions: Full-ceramic crowns showed clinically acceptable marginal adaptation values. The Feldspathic Cerec inLab ceramic system (Vitablocs Mark II) generally presented the lowest variance when compared with the other ceramics, except for the MG values on the mesial surface of the coronal section

  1. Correlation between micro-computed tomography and histomorphometry for assessment of new bone formation in a calvarial experimental model.

    PubMed

    Yeom, HeyRi; Blanchard, Steven; Kim, Seokjin; Zunt, Susan; Chu, Tien-Min G

    2008-03-01

    Conventional histologic or histomorphometric evaluation provides clear evidence of the bone healing process. However, the sample preparation process is tedious and destructive, and the three-dimensional (3D) anisotropic information of the bone trabeculae is compromised. Micro-computed tomography (microCT) has been introduced as an alternative to these traditional evaluation methods. microCT is noninvasive and provides a faster approach to evaluate and quantify cancellous bone. Most previous studies that used microCT have focused on studying trabecular structures of cancellous bone. In this study, we used microCT to analyze the micro-architecture of the regenerated membranous bone using a rabbit cranial defect model. Two 1 cm diameter circular bony defects were created in 12 New Zealand white rabbits. Specimens were harvested at 6 weeks and 12 weeks after surgery and were scanned using a MicroCT machine (Skyscan 1072, Aartselaar, Belgium). The specimens were then sectioned and stained with Goldner's trichrome. Bone volume density (BV/TV), bone surface density (BS/BV), and trabecular thickness (TbTh) were determined from histomorphometric and two-dimensional (2D) and 3D microCT analysis. Pearson's correlation coefficient (gamma), paired t-tests, and intraclass correlation coefficients from measurements between the 2D and 3D microCT and histomorphometry were calculated. There were very strong positive correlations of BV/TV between histomorphometric and 2D or 3D microCT measurements. Correlation between histomorphometric and 2D microCT measurements for BS/BV was moderate, whereas correlation between histomorphometric and 3D microCT measurements was weak. Weak correlations in TbTh among the three methods were found. In conclusion, the present study suggests that, in evaluating micro-architectures in regenerated bones, the correlation between measuring methods vary according to the features measured.

  2. Automated 3D-2D registration of X-ray microcomputed tomography with histological sections for dental implants in bone using chamfer matching and simulated annealing.

    PubMed

    Becker, Kathrin; Stauber, Martin; Schwarz, Frank; Beißbarth, Tim

    2015-09-01

    We propose a novel 3D-2D registration approach for micro-computed tomography (μCT) and histology (HI), constructed for dental implant biopsies, that finds the position and normal vector of the oblique slice from μCT that corresponds to HI. During image pre-processing, the implants and the bone tissue are segmented using a combination of thresholding, morphological filters and component labeling. After this, chamfer matching is employed to register the implant edges and fine registration of the bone tissues is achieved using simulated annealing. The method was tested on n=10 biopsies, obtained at 20 weeks after non-submerged healing in the canine mandible. The specimens were scanned with μCT 100 and processed for hard tissue sectioning. After registration, we assessed the agreement of bone to implant contact (BIC) using automated and manual measurements. Statistical analysis was conducted to test the agreement of the BIC measurements in the registered samples. Registration was successful for all specimens and agreement of the respective binary images was high (median: 0.90, 1.-3. Qu.: 0.89-0.91). Direct comparison of BIC yielded that automated (median 0.82, 1.-3. Qu.: 0.75-0.85) and manual (median 0.61, 1.-3. Qu.: 0.52-0.67) measures from μCT were significant positively correlated with HI (median 0.65, 1.-3. Qu.: 0.59-0.72) between μCT and HI groups (manual: R(2)=0.87, automated: R(2)=0.75, p<0.001). The results show that this method yields promising results and that μCT may become a valid alternative to assess osseointegration in three dimensions. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Imaging the Aqueous Humor Outflow Pathway in Human Eyes by Three-dimensional Micro-computed Tomography (3D micro-CT)

    SciTech Connect

    C Hann; M Bentley; A Vercnocke; E Ritman; M Fautsch

    2011-12-31

    The site of outflow resistance leading to elevated intraocular pressure in primary open-angle glaucoma is believed to be located in the region of Schlemm's canal inner wall endothelium, its basement membrane and the adjacent juxtacanalicular tissue. Evidence also suggests collector channels and intrascleral vessels may have a role in intraocular pressure in both normal and glaucoma eyes. Traditional imaging modalities limit the ability to view both proximal and distal portions of the trabecular outflow pathway as a single unit. In this study, we examined the effectiveness of three-dimensional micro-computed tomography (3D micro-CT) as a potential method to view the trabecular outflow pathway. Two normal human eyes were used: one immersion fixed in 4% paraformaldehyde and one with anterior chamber perfusion at 10 mmHg followed by perfusion fixation in 4% paraformaldehyde/2% glutaraldehyde. Both eyes were postfixed in 1% osmium tetroxide and scanned with 3D micro-CT at 2 {mu}m or 5 {mu}m voxel resolution. In the immersion fixed eye, 24 collector channels were identified with an average orifice size of 27.5 {+-} 5 {mu}m. In comparison, the perfusion fixed eye had 29 collector channels with a mean orifice size of 40.5 {+-} 13 {mu}m. Collector channels were not evenly dispersed around the circumference of the eye. There was no significant difference in the length of Schlemm's canal in the immersed versus the perfused eye (33.2 versus 35.1 mm). Structures, locations and size measurements identified by 3D micro-CT were confirmed by correlative light microscopy. These findings confirm 3D micro-CT can be used effectively for the non-invasive examination of the trabecular meshwork, Schlemm's canal, collector channels and intrascleral vasculature that comprise the distal outflow pathway. This imaging modality will be useful for non-invasive study of the role of the trabecular outflow pathway as a whole unit.

  4. Micro-computed Tomography Assessment of Dentinal Micro-cracks after Root Canal Preparation with TRUShape and Self-adjusting File Systems.

    PubMed

    Zuolo, Mario Luis; De-Deus, Gustavo; Belladonna, Felipe Gonçalves; Silva, Emmanuel João Nogueira Leal da; Lopes, Ricardo Tadeu; Souza, Erick Miranda; Versiani, Marco Aurélio; Zaia, Alexandre Augusto

    2017-04-01

    The aim of the present study was to evaluate the percentage frequency of dentinal micro-cracks observed after root canal preparation with TRUShape and Self-Adjusting File (SAF) systems by means of micro-computed tomography imaging analysis. A conventional full-sequence rotary system (BioRace) and a single-file reciprocation system (Reciproc) were used as reference techniques for comparison because of their known assertive cutting efficiency. Forty anatomically matched mandibular incisors were selected, scanned at a resolution of 14.25 μm, and assigned to 4 experimental groups (n = 10), according to the preparation protocol: TRUShape, SAF, BioRace, and Reciproc systems. After the experimental procedures, the specimens were scanned again, and the registered preoperative and postoperative cross-section images of the roots (n = 70,030) were screened to identify the presence of dentinal micro-cracks. Overall, dentinal defects were observed in 28,790 cross-section images (41.11%). In the TRUShape, SAF, BioRace, and Reciproc groups, dentinal micro-cracks were visualized in 56.47% (n = 9842), 42.38% (n = 7450), 32.90% (n = 5826), and 32.77% (n = 5672) of the slices, respectively. All dentinal defects observed in the postoperative data sets were already present in the corresponding preoperative images. None of the preparation systems induced the formation of new dentinal micro-cracks. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  5. The dental cavities of equine cheek teeth: three-dimensional reconstructions based on high resolution micro-computed tomography

    PubMed Central

    2012-01-01

    Background Recent studies reported on the very complex morphology of the pulp system in equine cheek teeth. The continuous production of secondary dentine leads to distinct age-related changes of the endodontic cavity. Detailed anatomical knowledge of the dental cavities in all ages is required to explain the aetiopathology of typical equine endodontic diseases. Furthermore, data on mandibular and maxillary pulp systems is in high demand to provide a basis for the development of endodontic therapies. However, until now examination of the pulp cavity has been based on either sectioned teeth or clinical computed tomography. More precise results were expected by using micro-computed tomography with a resolution of about 0.1 mm and three-dimensional reconstructions based on previous greyscale analyses and histological verification. The aim of the present study was to describe the physiological configurations of the pulp system within a wide spectrum of tooth ages. Results Maxillary teeth: All morphological constituents of the endodontic cavity were present in teeth between 4 and 16 years: Triadan 06s displayed six pulp horns and five root canals, Triadan 07-10s five pulp horns and four root canals and Triadan 11s seven pulp horns and four to six root canals. A common pulp chamber was most frequent in teeth ≤5 years, but was found even in a tooth of 9 years. A large variety of pulp configurations was observed within 2.5 and 16 years post eruption, but most commonly a separation into mesial and distal pulp compartments was seen. Maxillary cheek teeth showed up to four separate pulp compartments but the frequency of two, three and four pulp compartments was not related to tooth age (P > 0.05). In Triadan 06s, pulp horn 6 was always connected to pulp horns 1 and 3 and root canal I. In Triadan 11s, pulp horns 7 and 8 were present in variable constitutions. Mandibular teeth: A common pulp chamber was present in teeth up to 15 years, but most commonly seen in teeth ≤5

  6. Complex Odontoma: A Case Report with Micro-Computed Tomography Findings

    PubMed Central

    Santos, L. A. N.; Roque-Torres, G. D.; Oliveira, V. F.; Freitas, D. Q.

    2016-01-01

    Odontomas are the most common benign tumors of odontogenic origin. They are normally diagnosed on routine radiographs, due to the absence of symptoms. Histopathologic evaluation confirms the diagnosis especially in cases of complex odontoma, which may be confused during radiographic examination with an osteoma or other highly calcified bone lesions. The micro-CT is a new technology that enables three-dimensional analysis with better spatial resolution compared with cone beam computed tomography. Another great advantage of this technology is that the sample does not need special preparation or destruction in the sectioned area as in histopathologic evaluation. An odontoma with CBCT and microtomography images is presented in a 26-year-old man. It was first observed on panoramic radiographs and then by CBCT. The lesion and the impacted third molar were surgically excised using a modified Neumann approach. After removal, it was evaluated by histopathology and microtomography to confirm the diagnostic hypothesis. According to the results, micro-CT enabled the assessment of the sample similar to histopathology, without destruction of the sample. With further development, micro-CT could be a powerful diagnostic tool in future research. PMID:27293913

  7. Three-Dimensional Imaging Using Microcomputed Tomography For Studying Gaharu Morphology

    SciTech Connect

    Yazid, Khair'iah; Bin Awang, Mat Rasol; Mohamed, Abdul Aziz; Bin Hj Khalid, Mohd Ashhar; Masschaele, Bert; Abdullah, Mohd. Zaid; Saleh, Junita Mohamad

    2010-01-05

    To demonstrates the potential application of the high resolution X-ray micro-CT technique in the analysis of internal structure in Gaharu wood. Gaharu or internationally, Agar wood, is known for its fragrant resinous wood. The hardware device used in this study was an X-ray micro-CT scanner at Center of Tomography (UGCT), CT facility in Ghent University, Belgium. This technique allows the 3D investigation of the internal structure of the wood in a non-destructive way. Most of the data analysis was done with the software VG Studio Max and MATLAB. Here we present some preliminary results from three-dimensional images from a piece of high grade Gaharu. Micro-CT images of the specimens were obtained at 7 mum resolution. Besides a clear distinction between pores and material, some bright white areas occur in the reconstruction images. Not only the volume visualization is helpful, morphological parameters of open-pores and dark resins are calculated from these 3D data set. The micro-CT technique is a valid support for evaluating the pores structure and resin distribution in Gaharu.

  8. Quantitative Three-Dimensional Imaging of Live Avian Embryonic Morphogenesis Via Micro-computed Tomography

    PubMed Central

    Henning, Alyssa L.; Jiang, Michael X.; Yalcin, Huseyin C.; Butcher, Jonathan T.

    2013-01-01

    Many clinically relevant congenital malformations arise during mid to late embryonic stages. This period is challenging to image quantitatively in live embryos, necessitating the use of multiple specimens with increased experimental variability. Here we establish X-ray and blood-pool computed tomography (CT) contrast agent toxicity and teratogenesis thresholds for 3D Micro-CT imaging of live avian embryos. Day 4 chick embryos micro-injected with Visipaque™ (VP) developed for an additional 6 days without defect. X-ray radiation up to 798 mGy was nontoxic. Peak average contrast of 1,060 HU occurred within 1 hr of imaging at 50 μm resolution. VP-enhanced contrast persisted past 24 hr with delayed accumulation in the allantois. Regional volumes of VP-injected embryos were statistically identical to those of fixed embryos perfused with osmium tetroxide. We further quantified longitudinal volumetric morphogenesis of the allantois over 30 hr. These results demonstrate the safety and efficacy of contrast enhanced quantitative micro-CT imaging for live embryos. PMID:21761480

  9. Determination of strain fields in porous shape memory alloys using micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Bormann, Therese; Friess, Sebastian; de Wild, Michael; Schumacher, Ralf; Schulz, Georg; Müller, Bert

    2010-09-01

    Shape memory alloys (SMAs) belong to 'intelligent' materials since the metal alloy can change its macroscopic shape as the result of the temperature-induced, reversible martensite-austenite phase transition. SMAs are often applied for medical applications such as stents, hinge-less instruments, artificial muscles, and dental braces. Rapid prototyping techniques, including selective laser melting (SLM), allow fabricating complex porous SMA microstructures. In the present study, the macroscopic shape changes of the SMA test structures fabricated by SLM have been investigated by means of micro computed tomography (μCT). For this purpose, the SMA structures are placed into the heating stage of the μCT system SkyScan 1172™ (SkyScan, Kontich, Belgium) to acquire three-dimensional datasets above and below the transition temperature, i.e. at room temperature and at about 80°C, respectively. The two datasets were registered on the basis of an affine registration algorithm with nine independent parameters - three for the translation, three for the rotation and three for the scaling in orthogonal directions. Essentially, the scaling parameters characterize the macroscopic deformation of the SMA structure of interest. Furthermore, applying the non-rigid registration algorithm, the three-dimensional strain field of the SMA structure on the micrometer scale comes to light. The strain fields obtained will serve for the optimization of the SLM-process and, more important, of the design of the complex shaped SMA structures for tissue engineering and medical implants.

  10. Predicting mouse vertebra strength with micro-computed tomography-derived finite element analysis.

    PubMed

    Nyman, Jeffry S; Uppuganti, Sasidhar; Makowski, Alexander J; Rowland, Barbara J; Merkel, Alyssa R; Sterling, Julie A; Bredbenner, Todd L; Perrien, Daniel S

    2015-01-01

    As in clinical studies, finite element analysis (FEA) developed from computed tomography (CT) images of bones are useful in pre-clinical rodent studies assessing treatment effects on vertebral body (VB) strength. Since strength predictions from microCT-derived FEAs (μFEA) have not been validated against experimental measurements of mouse VB strength, a parametric analysis exploring material and failure definitions was performed to determine whether elastic μFEAs with linear failure criteria could reasonably assess VB strength in two studies, treatment and genetic, with differences in bone volume fraction between the control and the experimental groups. VBs were scanned with a 12-μm voxel size, and voxels were directly converted to 8-node, hexahedral elements. The coefficient of determination or R (2) between predicted VB strength and experimental VB strength, as determined from compression tests, was 62.3% for the treatment study and 85.3% for the genetic study when using a homogenous tissue modulus (E t) of 18 GPa for all elements, a failure volume of 2%, and an equivalent failure strain of 0.007. The difference between prediction and measurement (that is, error) increased when lowering the failure volume to 0.1% or increasing it to 4%. Using inhomogeneous tissue density-specific moduli improved the R (2) between predicted and experimental strength when compared with uniform E t=18 GPa. Also, the optimum failure volume is higher for the inhomogeneous than for the homogeneous material definition. Regardless of model assumptions, μFEA can assess differences in murine VB strength between experimental groups when the expected difference in strength is at least 20%.

  11. Evaluating tooth restorations: micro-computed tomography in practical training for students in dentistry

    NASA Astrophysics Data System (ADS)

    Deyhle, Hans; Schmidli, Fredy; Krastl, Gabriel; Müller, Bert

    2010-09-01

    Direct composite fillings belong to widespread tooth restoration techniques in dental medicine. The procedure consists of successive steps, which include etching of the prepared tooth surface, bonding and placement of composite in incrementally built up layers. Durability and lifespan of the composite inlays strongly depend on the accurate completion of the individual steps to be also realized by students in dental medicine. Improper handling or nonconformity in the bonding procedure often lead to air enclosures (bubbles) as well as to significant gaps between the composite layers or at the margins of the restoration. Traditionally one analyzes the quality of the restoration cutting the tooth in an arbitrarily selected plane and inspecting this plane by conventional optical microscopy. Although the precision of this established method is satisfactory, it is restricted to the selected two-dimensional plane. Rather simple micro computed tomography (μCT) systems, such as SkyScan 1174™, allows for the non-destructive three-dimensional imaging of restored teeth ex vivo and virtually cutting the tomographic data in any desired direction, offering a powerful tool for inspection of the restored tooth with micrometer resolution before cutting and thus also to select a two-dimensional plane with potential defects. In order to study the influence of the individual steps on the resulted tooth restoration, direct composite fillings were placed in mod cavities of extracted teeth. After etching, an adhesive was applied in half of the specimens. From the tomographic datasets, it becomes clear that gaps occur more frequently when bonding is omitted. The visualization of air enclosures offers to determine the probability to find a micrometer-sized defect using an arbitrarily selected cutting plane for inspection.

  12. Quantitative micro-computed tomography: a non-invasive method to assess equivalent bone mineral density.

    PubMed

    Nazarian, Ara; Snyder, Brian D; Zurakowski, David; Müller, Ralph

    2008-08-01

    One of the many applications of micro computed tomography (microCT) is to accurately visualize and quantify cancellous bone microstructure. However, microCT based assessment of bone mineral density has yet to be thoroughly investigated. Specifically, the effects of varying imaging parameters, such as tube voltage (kVp), current (microA), integration time (ms), object to X-ray source distance (mm), projection number, detector array size and imaging media (surrounding the specimen), on the relationship between equivalent tissue density (rhoEQ) and its linear attenuation coefficient (micro) have received little attention. In this study, in house manufactured, hydrogen dipotassium phosphate liquid calibration phantoms (K2HPO4) were employed in addition to a resin embedded hydroxyapatite solid calibration phantoms supplied by Scanco Medical AG Company. Variations in current, integration time and projection number had no effect on the conversion relationship between micro and rhoEQ for the K2HPO4 and Scanco calibration phantoms [p>0.05 for all cases]. However, as expected, variations in scanning tube voltage, object to X-ray source distance, detector array size and imaging media (referring to the solution that surrounds the specimen in the imaging vial) significantly affected the conversion relationship between mu and rhoEQ for K2HPO4 and Scanco calibration phantoms [p<0.05 for all cases]. A multivariate linear regression approach was used to estimate rhoEQ based on attenuation coefficient, tube voltage, object to X-ray source distance, detector array size and imaging media for K2HPO4 liquid calibration phantoms, explaining 90% of the variation in rhoEQ. Furthermore, equivalent density values of bovine cortical bone (converted from attenuation coefficient to equivalent density using the K2HPO4 liquid calibration phantoms) samples highly correlated [R2=0.92] with the ash densities of the samples. In conclusion, Scanco calibration phantoms can be used to assess equivalent

  13. Correlation analysis of cortical geometry of tibia and humerus of white leghorns using clinical quantitative computed tomography and microcomputed tomography scans1.

    PubMed

    Regmi, P; Cox, A G; Robison, C I; Karcher, D M

    2017-03-24

    Peripheral quantitative computed tomography (QCT) has been used in poultry bone research in recent years to analyze cortical and cross-sectional geometry. For QCT to be used as a standard research tool for analysis of bones of laying hens (cortical thickness <2 mm), the accuracy of the scans must be assessed. The primary difference between the QCT and micro-computed tomography (micro-CT) is image resolution. Image resolution is inversely related to the pixel size. The aim of the current study was to correlate the cortical parameters measured using clinical CT scans with the measurements from micro-CT, the current gold standard. A total of 15 tibiae and 14 humeri of Lohmann White hens was scanned using clinical CT and micro-CT. Reconstruction of the scans generated images with final voxel resolution of 195 μm for clinical CT scans and 46 μm for micro-CT scans. Cortical and total area were measured using MIMICS® software at proximal, middle, and distal locations of 20 mm sections of humerus diaphysis and 30 mm sections of tibia diaphysis. The total area for proximal and middle locations as well as proximal cortical area measurements for humeri produced strong correlation coefficients (R ≥ 0.70). Moderate strength correlation coefficients (R = 0.40 to 0.60) in humeri were seen in middle and distal cortical areas. Distal total area in humeri displayed a weak correlation coefficient (R ≤ 0.3; P = 0.25). Overall, tibiae demonstrated a weaker correlation. Proximal and middle cortical areas indicated moderate correlation coefficients (R = 0.40 to 0.60), while proximal and middle total areas accompanied by distal cortical and total area displayed weak correlation coefficients (R ≤ 0.3). Only the middle cortical area measurement for tibiae was significant (P = 0.03). These results indicate stronger correlation for humeri measurements among the scans than tibia. Overall, cross-sectional area measurements were only low to moderately correlated between clinical

  14. Micro-Computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

    PubMed Central

    Khobragade, P.; Jain, A.; Setlur Nagesh, S. V.; Andreana, S.; Dziak, R.; Sunkara, S. K.; Sunkara, S.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2015-01-01

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine’s jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custom-built micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor in-vivo bone regeneration studies for greater regenerative process understanding. PMID:26869742

  15. Micro-Computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model.

    PubMed

    Khobragade, P; Jain, A; Setlur Nagesh, S V; Andreana, S; Dziak, R; Sunkara, S K; Sunkara, S; Bednarek, D R; Rudin, S; Ionita, C N

    2015-03-17

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custom-built micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor in-vivo bone regeneration studies for greater regenerative process understanding.

  16. Micro-computed tomography (CT) based assessment of dental regenerative therapy in the canine mandible model

    NASA Astrophysics Data System (ADS)

    Khobragade, P.; Jain, A.; Setlur Nagesh, S. V.; Andreana, S.; Dziak, R.; Sunkara, S. K.; Sunkara, S.; Bednarek, D. R.; Rudin, S.; Ionita, C. N.

    2015-03-01

    High-resolution 3D bone-tissue structure measurements may provide information critical to the understanding of the bone regeneration processes and to the bone strength assessment. Tissue engineering studies rely on such nondestructive measurements to monitor bone graft regeneration area. In this study, we measured bone yield, fractal dimension and trabecular thickness through micro-CT slices for different grafts and controls. Eight canines underwent surgery to remove a bone volume (defect) in the canine's jaw at a total of 44 different locations. We kept 11 defects empty for control and filled the remaining ones with three regenerative materials; NanoGen (NG), a FDA-approved material (n=11), a novel NanoCalcium Sulfate (NCS) material (n=11) and NCS alginate (NCS+alg) material (n=11). After a minimum of four and eight weeks, the canines were sacrificed and the jaw samples were extracted. We used a custombuilt micro-CT system to acquire the data volume and developed software to measure the bone yield, fractal dimension and trabecular thickness. The software used a segmentation algorithm based on histograms derived from volumes of interest indicated by the operator. Using bone yield and fractal dimension as indices we are able to differentiate between the control and regenerative material (p<0.005). Regenerative material NCS showed an average 63.15% bone yield improvement over the control sample, NCS+alg showed 55.55% and NanoGen showed 37.5%. The bone regeneration process and quality of bone were dependent upon the position of defect and time period of healing. This study presents one of the first quantitative comparisons using non-destructive Micro-CT analysis for bone regenerative material in a large animal with a critical defect model. Our results indicate that Micro-CT measurement could be used to monitor invivo bone regeneration studies for greater regenerative process understanding.

  17. Intramembranous Bone Healing Process Subsequent to Tooth Extraction in Mice: Micro-Computed Tomography, Histomorphometric and Molecular Characterization

    PubMed Central

    Vieira, Andreia Espindola; Repeke, Carlos Eduardo; Ferreira Junior, Samuel de Barros; Colavite, Priscila Maria; Biguetti, Claudia Cristina; Oliveira, Rodrigo Cardoso; Assis, Gerson Francisco; Taga, Rumio; Trombone, Ana Paula Favaro; Garlet, Gustavo Pompermaier

    2015-01-01

    Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray) characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0h), the development of a provisional immature granulation tissue is evident (7d), characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa), cytokines (TNFα, IL-10), chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4), matrix (Col1a1-2, ITGA4, VTN, MMP1a) and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146) markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14d), characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9), bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST) markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2). No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21d) when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the histomorphometric

  18. Intramembranous bone healing process subsequent to tooth extraction in mice: micro-computed tomography, histomorphometric and molecular characterization.

    PubMed

    Vieira, Andreia Espindola; Repeke, Carlos Eduardo; Ferreira Junior, Samuel de Barros; Colavite, Priscila Maria; Biguetti, Claudia Cristina; Oliveira, Rodrigo Cardoso; Assis, Gerson Francisco; Taga, Rumio; Trombone, Ana Paula Favaro; Garlet, Gustavo Pompermaier

    2015-01-01

    Bone tissue has a significant potential for healing, which involves a significant the interplay between bone and immune cells. While fracture healing represents a useful model to investigate endochondral bone healing, intramembranous bone healing models are yet to be developed and characterized. In this study, a micro-computed tomography, histomorphometric and molecular (RealTimePCRarray) characterization of post tooth-extraction alveolar bone healing was performed on C57Bl/6 WT mice. After the initial clot dominance (0 h), the development of a provisional immature granulation tissue is evident (7 d), characterized by marked cell proliferation, angiogenesis and inflammatory cells infiltration; associated with peaks of growth factors (BMP-2-4-7,TGFβ1,VEGFa), cytokines (TNFα, IL-10), chemokines & receptors (CXCL12, CCL25, CCR5, CXCR4), matrix (Col1a1-2, ITGA4, VTN, MMP1a) and MSCs (CD105, CD106, OCT4, NANOG, CD34, CD146) markers expression. Granulation tissue is sequentially replaced by more mature connective tissue (14 d), characterized by inflammatory infiltrate reduction along the increased bone formation, marked expression of matrix remodeling enzymes (MMP-2-9), bone formation/maturation (RUNX2, ALP, DMP1, PHEX, SOST) markers, and chemokines & receptors associated with healing (CCL2, CCL17, CCR2). No evidences of cartilage cells or tissue were observed, strengthening the intramembranous nature of bone healing. Bone microarchitecture analysis supports the evolving healing, with total tissue and bone volumes as trabecular number and thickness showing a progressive increase over time. The extraction socket healing process is considered complete (21 d) when the dental socket is filled by trabeculae bone with well-defined medullary canals; it being the expression of mature bone markers prevalent at this period. Our data confirms the intramembranous bone healing nature of the model used, revealing parallels between the gene expression profile and the

  19. Micro-computed tomography pore-scale study of flow in porous media: Effect of voxel resolution

    NASA Astrophysics Data System (ADS)

    Shah, S. M.; Gray, F.; Crawshaw, J. P.; Boek, E. S.

    2016-09-01

    A fundamental understanding of flow in porous media at the pore-scale is necessary to be able to upscale average displacement processes from core to reservoir scale. The study of fluid flow in porous media at the pore-scale consists of two key procedures: Imaging - reconstruction of three-dimensional (3D) pore space images; and modelling such as with single and two-phase flow simulations with Lattice-Boltzmann (LB) or Pore-Network (PN) Modelling. Here we analyse pore-scale results to predict petrophysical properties such as porosity, single-phase permeability and multi-phase properties at different length scales. The fundamental issue is to understand the image resolution dependency of transport properties, in order to up-scale the flow physics from pore to core scale. In this work, we use a high resolution micro-computed tomography (micro-CT) scanner to image and reconstruct three dimensional pore-scale images of five sandstones (Bentheimer, Berea, Clashach, Doddington and Stainton) and five complex carbonates (Ketton, Estaillades, Middle Eastern sample 3, Middle Eastern sample 5 and Indiana Limestone 1) at four different voxel resolutions (4.4 μm, 6.2 μm, 8.3 μm and 10.2 μm), scanning the same physical field of view. Implementing three phase segmentation (macro-pore phase, intermediate phase and grain phase) on pore-scale images helps to understand the importance of connected macro-porosity in the fluid flow for the samples studied. We then compute the petrophysical properties for all the samples using PN and LB simulations in order to study the influence of voxel resolution on petrophysical properties. We then introduce a numerical coarsening scheme which is used to coarsen a high voxel resolution image (4.4 μm) to lower resolutions (6.2 μm, 8.3 μm and 10.2 μm) and study the impact of coarsening data on macroscopic and multi-phase properties. Numerical coarsening of high resolution data is found to be superior to using a lower resolution scan because it

  20. Improved accuracy of cortical bone mineralization measured by polychromatic microcomputed tomography using a novel high mineral density composite calibration phantom

    SciTech Connect

    Deuerling, Justin M.; Rudy, David J.; Niebur, Glen L.; Roeder, Ryan K.

    2010-09-15

    Purpose: Microcomputed tomography (micro-CT) is increasingly used as a nondestructive alternative to ashing for measuring bone mineral content. Phantoms are utilized to calibrate the measured x-ray attenuation to discrete levels of mineral density, typically including levels up to 1000 mg HA/cm{sup 3}, which encompasses levels of bone mineral density (BMD) observed in trabecular bone. However, levels of BMD observed in cortical bone and levels of tissue mineral density (TMD) in both cortical and trabecular bone typically exceed 1000 mg HA/cm{sup 3}, requiring extrapolation of the calibration regression, which may result in error. Therefore, the objectives of this study were to investigate (1) the relationship between x-ray attenuation and an expanded range of hydroxyapatite (HA) density in a less attenuating polymer matrix and (2) the effects of the calibration on the accuracy of subsequent measurements of mineralization in human cortical bone specimens. Methods: A novel HA-polymer composite phantom was prepared comprising a less attenuating polymer phase (polyethylene) and an expanded range of HA density (0-1860 mg HA/cm{sup 3}) inclusive of characteristic levels of BMD in cortical bone or TMD in cortical and trabecular bone. The BMD and TMD of cortical bone specimens measured using the new HA-polymer calibration phantom were compared to measurements using a conventional HA-polymer phantom comprising 0-800 mg HA/cm{sup 3} and the corresponding ash density measurements on the same specimens. Results: The HA-polymer composite phantom exhibited a nonlinear relationship between x-ray attenuation and HA density, rather than the linear relationship typically employed a priori, and obviated the need for extrapolation, when calibrating the measured x-ray attenuation to high levels of mineral density. The BMD and TMD of cortical bone specimens measured using the conventional phantom was significantly lower than the measured ash density by 19% (p<0.001, ANCOVA) and 33% (p<0

  1. The role of symbiotic algae in the formation of the coral polyp skeleton: 3-D morphological study based on X-ray microcomputed tomography

    NASA Astrophysics Data System (ADS)

    Iwasaki, Shinya; Inoue, Mayuri; Suzuki, Atsushi; Sasaki, Osamu; Kano, Harumasa; Iguchi, Akira; Sakai, Kazuhiko; Kawahata, Hodaka

    2016-09-01

    Symbiotic algae of primary polyps play an important role in calcification of coral skeletons. However, the function of the symbiotic algae, including the way they influence the physical features of their host skeleton under various conditions, is not well understood. We used X-ray microcomputed tomography to observe skeletal shape characteristics in symbiotic and aposymbiotic primary polyps of Acropora digitifera that were cultured at various temperature and pCO2 levels (temperature 27, 29, 33°C; pCO2 400, 800, 1000 µatm). Symbiotic polyps had a basal plate with a well-developed folding margin supporting the branched skeleton, whereas aposymbiotic ones did not. The features of the folding margin suggest that it might be the initial growth stage of the epitheca. In addition, three-dimensional (3-D) morphological measurements made by X-ray microcomputed tomography show that the branched skeletons of symbiotic primary polyps were taller than those of aposymbiotic ones, suggesting that zooxanthellae in coral primary polyps play a critical role in the height growth of skeletal branches. Furthermore, results of the temperature- and pCO2-controlled experiments suggest that global warming might greatly affect the activity of zooxanthellae, whereas ocean acidification might reduce calcification by damaging the coral host itself. Our findings provide new knowledge about the role of zooxanthellae in coral calcification.

  2. Design and validation of a novel bioreactor principle to combine online micro-computed tomography monitoring and mechanical loading in bone tissue engineering.

    PubMed

    Hagenmüller, Henri; Hitz, Marco; Merkle, Hans P; Meinel, Lorenz; Müller, Ralph

    2010-01-01

    Mechanical loading plays an important role in bone remodeling in vivo and, therefore, has been suggested as a key parameter in stem cell-based engineering of bone-like tissue in vitro. However, the optimization of loading protocols during stem cell differentiation and subsequent bone-like tissue formation is challenged by multiple input factors, which are difficult to control and validate. These include the variable cellular performance of cells harvested from different patients, nonstandardized culture media components, the choice of the biomaterial forming the scaffold, and its morphology, impacting a broader validity of mechanical stimulation regimens. To standardize the cell culture of bone-like tissue constructs, we suggest the involvement of time-lapsed feedback loops. For this purpose we present a prototype bioreactor that combines online, nondestructive monitoring using micro-computed tomography and direct mechanical loading of three-dimensional tissue engineering constructs. Validation of this system showed displacement steps down to 1 microm and cyclic sinusoidal loadings of up to 10 Hz. Load detection resolution was 0.01 N, and micro-computed tomography data were of high quality. For the first time, the developed bioreactor links time-lapsed, nondestructive, and dynamic imaging with mechanical stimulation, designed for cell culture under sterile conditions. This system is believed to substantially improve today's experimental options to study and optimize osteogenic stem cell culture and differentiation at the interface with mechanical stimulation.

  3. Comparative micro-computed tomography evaluation of apical root canal transportation with the use of ProTaper, RaCe and Safesider systems in human teeth.

    PubMed

    Ceyhanli, Kadir T; Erdilek, Necdet; Tatar, Ilkan; Cetintav, Bekir

    2014-04-01

    The aim of this study was to compare apical centring ability of nickel titanium (NiTi) ProTaper, RaCe and mainly stainless steel Safesider systems using micro-computed tomography. Thirty freshly extracted mandibular molars with two separate mesial canals and separate foramina were used for the study. Mesial roots were embedded in acrylic resin and instrumented with the ProTaper, RaCe or Safesider systems. Root canal transportation and centring ability of the instruments were evaluated using superimposed micro-computed tomography images of the apical 4 mm of the roots taken at 1 mm intervals. One-way analysis of variance and post hoc Tukey's tests were performed to compare apical transportations. Significant differences were observed between groups at the apical 1, 2 and 3 mm levels (P < 0.05). The reciprocating Safesider system transported root canals significantly more than the other two NiTi systems in the apical 1 mm level (P = 0.001) and more than RaCe system in the apical 2 mm level (P = 0.003). The ProTaper instruments caused more apical root canal transportation than did RaCe instruments at apical 3 mm (P = 0.045). NiTi instrumentation systems showed better centring ability than the mainly stainless steel Safesider system because of the flexible structure of the NiTi alloy.

  4. Grapevine petioles are more sensitive to drought induced embolism than stems: evidence from in vivo MRI and microcomputed tomography observations of hydraulic vulnerability segmentation.

    PubMed

    Hochberg, Uri; Albuquerque, Caetano; Rachmilevitch, Shimon; Cochard, Herve; David-Schwartz, Rakefet; Brodersen, Craig R; McElrone, Andrew; Windt, Carel W

    2016-09-01

    The 'hydraulic vulnerability segmentation' hypothesis predicts that expendable distal organs are more susceptible to water stress-induced embolism than the main stem of the plant. In the current work, we present the first in vivo visualization of this phenomenon. In two separate experiments, using magnetic resonance imaging or synchrotron-based microcomputed tomography, grapevines (Vitis vinifera) were dehydrated while simultaneously scanning the main stems and petioles for the occurrence of emboli at different xylem pressures (Ψx ). Magnetic resonance imaging revealed that 50% of the conductive xylem area of the petioles was embolized at a Ψx of -1.54 MPa, whereas the stems did not reach similar losses until -1.9 MPa. Microcomputed tomography confirmed these findings, showing that approximately half the vessels in the petioles were embolized at a Ψx of -1.6 MPa, whereas only few were embolized in the stems. Petioles were shown to be more resistant to water stress-induced embolism than previously measured with invasive hydraulic methods. The results provide the first direct evidence for the hydraulic vulnerability segmentation hypothesis and highlight its importance in grapevine responses to severe water stress. Additionally, these data suggest that air entry through the petiole into the stem is unlikely in grapevines during drought.

  5. Comparative evaluation of root canal preparations of maxillary first molars with self-adjusting file, reciproc single file, and revo-s rotary file: A micro-computed tomography study.

    PubMed

    Ahmetoglu, Fuat; Keles, Ali; Simsek, Neslihan; Ocak, M Sinan; Yologlu, Saim

    2015-01-01

    This study was aimed to use micro-computed tomography (μ-CT) to evaluate the canal shaping properties of three nickel-titanium instruments, Self-Adjusting File (SAF), Reciproc, and Revo-S rotary file, in maxillary first molars. Thirty maxillary molars were scanned preoperatively by using micro-computed tomography (μ-CT) scans at 13,68 μm resolution. The teeth were randomly assigned to three groups (n = 10). The root canals were shaped with SAF, Reciproc, and Revo-S, respectively. The shaped root canals were rescanned. Changes in canal volumes and surface areas were compared with preoperative values. The data were analyzed using Kruskal-Wallis and Conover's post hoc tests, with p < .05 denoting a statistically significant difference. Preoperatively canal volumes and surface area were statistically similar among the three groups (p > .05). There were statistically significant differences in all measures comparing preoperative and postoperative canal models (p = 0.0001). These differences occurred after instrumentation among the three experimental groups showed no statistically significant difference for volume (p > .05). Surface area showed the similar activity in buccal canals in each of the three techniques whereas no statistically significant difference was detected among surface area, the SAF, and the Revo-S in the palatal (P) canal. Each of three shaping system showed the similar volume activity in all canals, but SAF and Revo-S provided more effectively root planning in comparison with Reciproc in P canal.

  6. Micro-Computed Tomography Study of Filling Material Removal from Oval-shaped Canals by Using Rotary, Reciprocating, and Adaptive Motion Systems.

    PubMed

    Crozeta, Bruno Monguilhott; Silva-Sousa, Yara Teresinha Correa; Leoni, Graziela Bianchi; Mazzi-Chaves, Jardel Francisco; Fantinato, Thais; Baratto-Filho, Flares; Sousa-Neto, Manoel Damião

    2016-05-01

    This study evaluated filling material removal from distal oval-shaped canals of mandibular molars with rotary, reciprocating, and adaptive motion systems by using micro-computed tomography. After cone-beam computed tomography scanning, 21 teeth were selected, prepared up to a size 40 file, root filled, and divided into 3 groups (n = 7) according to the filling material removal technique: group PTUR, ProTaper Universal Retreatment combined with ProTaper Universal F2, F3, F4, and F5 files; group RP, Reciproc R50 file; and group TFA: TF Adaptive 50.04 files. The specimens were scanned preoperatively and postoperatively to assess filling material removal by using micro-computed tomography imaging, and the percent volume of residual filling material was calculated. The statistical analysis showed the lowest percent volume of residual filling material at the coronal third in all groups (P < .05). There was no significant difference among the systems in the coronal third (P > .05). In the middle third, group TFA (31.2 ± 10.1) showed lower volume of residual filling material than group RP (52.4 ± 14.1) (P < .05). In the apical third, groups TFA (44.8 ± 20.6) and PTUR (48.6 ± 16.8) presented a lower percent volume of filling material than group RP (70.6 ± 7.2) (P < .05), as confirmed by the qualitative analysis. The use of the adaptive motion increased the amount of root filling removed in the middle and apical thirds compared with the reciprocating motion. However, no technique was able to completely remove the filling material from the canals. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  7. The effect of risedronate on bone mineralization as measured by micro-computed tomography with synchrotron radiation: correlation to histomorphometric indices of turnover.

    PubMed

    Borah, Babul; Ritman, Erik L; Dufresne, Thomas E; Jorgensen, Steven M; Liu, Sheng; Sacha, Jarek; Phipps, Roger J; Turner, Russell T

    2005-07-01

    The primary goal of our study was to determine changes in bone mineralization in postmenopausal osteoporotic women treated for 3 years with risedronate or placebo. A secondary goal was to determine the relationship between mineralization and indices of bone turnover measured on the same biopsies. The degree of mineralization was measured by micro-computed tomography using Synchrotron radiation (Synchrotron microCT) in the trabecular bone of paired transiliac biopsies taken at baseline and after 3 years of treatment from patients receiving risedronate 5 mg daily (n=11) or placebo (n=8). In the risedronate-treated patients, the average mineralization (Avg-MIN) and peak mineralization (Peak-MIN) at 3 years were significantly increased from baseline by 4.7% (P<0.0001) and 5.4% (P=0.0003), respectively and showed significant negative correlation to turnover indices. In the placebo-treated patients, the increases in Avg-MIN (2.0%) and Peak-MIN (1.6%) were not significantly different from baseline and correlation to turnover indices was weaker. Risedronate significantly reduced the ratio of low- to high-mineralized bone fractions estimated by volume (BMR-V) and surface area (BMR-S) by 70.1% and 54.1%, respectively from baseline. These changes were consistent with the significant reduction of turnover from baseline assessed by reductions in mineralizing surface, MS/BS (-72.8%); activation frequency, Ac.F (-60.4%); and bone formation rate, BFR-BV (-63.6%) in the same biopsies in the risedronate-treated patients. Comparing the pair-wise changes from baseline, risedronate significantly reduced the low-mineralized bone fraction in comparison to placebo, as indicated by a larger reduction of BMR-V (P=0.015) and BMR-S (P=0.035). In the risedronate group, BMR-V and BMR-S showed significant positive correlation to MS/BS (R2: 0.83 and 0.92, respectively). The correlations to Ac.F and BFR-BV were also significant, with BMR-S showing a strong relation (R2: 0.77 and 0.79, respectively

  8. Shaping ability of two nickel-titanium instruments activated by continuous rotation or adaptive motion: a micro-computed tomography study.

    PubMed

    Pedullà, E; Plotino, G; Grande, N M; Avarotti, G; Gambarini, G; Rapisarda, E; Mannocci, F

    2016-11-01

    The objective of the study was to evaluate the shaping ability of curved root canals using Twisted File Adaptive (TFA) files (SybronEndo, Orange, CA) and Mtwo (Sweden & Martina, Padova, Italy) activated by continuous rotation or adaptive motion. Thirty-two mandibular molars with two separate mesial canals and severe angles of curvature were selected. Each canal was randomly assigned to one of the four experimental groups (n = 16): TFA and Mtwo files used in continuous rotation (groups 1 and 3) or in adaptive motion (groups 2 and 4). Root canals before and after preparation were assessed by micro-computed tomography. Volume, surface area, canal transportation, and centering ability were recorded and analyzed using two-way analyses of variance. Volume and surface area increased less with TFA files in continuous rotation than in other groups (P < 0.001 and P < 0.01, respectively, for each comparison) that were not different (P > 0.05). TFA files had significantly less transportation and higher centering ability than Mtwo both in continuous and adaptive motion (P < 0.0001). Centering ratio, but not canal transportation, was improved by adaptive motion compared with continuous rotation for both instruments (P < 0.01). However, no differences were found in canal transportation and centering ability in the apical third for both instruments and motions (P > 0.05). No difference between the devices and kinematics was found in the apical third; TFA performed significantly better in the middle and coronal parts of the root canal. The use of NiTi files made by heat-treated alloy and/or adaptive motion could improve the qualities of root canal shaping rather than the use of conventional NiTi instruments and/or continuous rotation in the coronal and middle thirds of the root canals, but not in the apical one. Moreover, these findings encourage the use of adaptive motion with conventional NiTi files to improve centering ability without affecting other

  9. A Comparison of Using a Microcomputer, Precision Teaching, and Worksheets to Master Basic Multiplication Facts.

    ERIC Educational Resources Information Center

    Vacc, Nancy Nesbitt

    1992-01-01

    Discusses methods for teaching mathematics skills and describes a study of third graders that compared student performances on worksheets, a microcomputer drill and practice program, and daily one-minute timing procedures of precision teaching for independent practice of multiplication facts. Results indicate that precision teaching was the most…

  10. X-Ray Micro-Computed Tomography of Apollo Samples as a Curation Technique Enabling Better Research

    NASA Technical Reports Server (NTRS)

    Ziegler, R. A.; Almeida, N. V.; Sykes, D.; Smith, C. L.

    2014-01-01

    X-ray micro-computed tomography (micro-CT) is a technique that has been used to research meteorites for some time and many others], and recently it is becoming a more common tool for the curation of meteorites and Apollo samples. Micro-CT is ideally suited to the characterization of astromaterials in the curation process as it can provide textural and compositional information at a small spatial resolution rapidly, nondestructively, and without compromising the cleanliness of the samples (e.g., samples can be scanned sealed in Teflon bags). This data can then inform scientists and curators when making and processing future sample requests for meteorites and Apollo samples. Here we present some preliminary results on micro-CT scans of four Apollo regolith breccias. Methods: Portions of four Apollo samples were used in this study: 14321, 15205, 15405, and 60639. All samples were 8-10 cm in their longest dimension and approximately equant. These samples were micro-CT scanned on the Nikon HMXST 225 System at the Natural History Museum in London. Scans were made at 205-220 kV, 135-160 microamps beam current, with an effective voxel size of 21-44 microns. Results: Initial examination of the data identify a variety of mineral clasts (including sub-voxel FeNi metal grains) and lithic clasts within the regolith breccias. Textural information within some of the lithic clasts was also discernable. Of particular interest was a large basalt clast (approx.1.3 cc) found within sample 60639, which appears to have a sub-ophitic texture. Additionally, internal void space, e.g., fractures and voids, is readily identifiable. Discussion: It is clear from the preliminary data that micro-CT analyses are able to identify important "new" clasts within the Apollo breccias, and better characterize previously described clasts or igneous samples. For example, the 60639 basalt clast was previously believed to be quite small based on its approx.0.5 sq cm exposure on the surface of the main mass

  11. Technical note: Three-dimensional imaging of rumen tissue for morphometric analysis using micro-computed tomography.

    PubMed

    Steele, M A; Garcia, F; Lowerison, M; Gordon, K; Metcalf, J A; Hurtig, M

    2014-12-01

    Rumen development in calves has been evaluated by measuring papillae length, width, and density using microscopy for over 50 yr. Although common in the literature, disadvantages to this method exist, such as large variations in rumen papillae size and shape, small numbers of total papillae being measured, and the time required. The objective of this study was to develop a more effective technique for assessing rumen papillae using micro-computed tomography (micro-CT) and to compare this technique with microscopy. Rumen tissue was collected from the ventral sac of 20 postweaned bull calves at 55 d of age, immediately fixed in 10% neutral buffered formalin for 48 h, and stored in 70% ethanol at 4°C before the contrast enhancement. After evaluation of contrast-enhancement protocols, it was determined that mercury chloride provided the most pronounced contrast for accurate micro-CT imaging based on relative density of the papillae. A 1-cm(2) tissue section from the ventral sac of all bull calves was tensioned on a rapid prototyped curved plastic holder and imaged at 4 5 μm resolution for 56 min using a GE Locus Explore micro-CT (General Electric, Milwaukee, WI). MicroView V2.2 software (General Electric) was used to create a 3-dimensional virtual model of the entire sample. The length and width of papillae were measured 3-dimensionally and compared with measurements of papillae under the light microscope taken from the same region. The length and width measurements using micro-CT (2.47 ± 0.12 and 0.55 ± 0.01 mm) compared with light microscope (2.96 ± 0.03 and 0.86 ± 0.01 mm) were significantly smaller. The difference may reflect a more accurate determination in the base of the rumen tissue with micro-CT or the specificity of mercury chloride to bind only to intact rumen tissue. The mean number of papillae per centimeter squared viewed using micro-CT was 128.5 ± 33.9 with a total surface area of 681.8 ± 112.4 mm(2) and volume of 156 mm(3) per sample. Micro

  12. Alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification: a three-dimensional microcomputed tomography analysis.

    PubMed

    Al-Shabeeb, Munirah Saleh; Al-Askar, Mansour; Al-Rasheed, Abdulaziz; Babay, Nadir; Javed, Fawad; Wang, Hom-Lay; Al-Hezaimi, Khalid

    2012-08-01

    Previous studies assessed bone remodeling after a single tooth extraction; however, the effect of multiple contiguous teeth extractions around immediate implant remains unknown. The aim of this microcomputed tomographic investigation is to analyze the alveolar bone remodeling around immediate implants placed in accordance with the extraction socket classification (ESC). Under general anesthesia, 10 beagle dogs underwent atraumatic tooth extractions. Animals were randomly divided into three groups, with 16 sites per group: 1) ESC-1, single tooth extraction; 2) ESC-2, two contiguous teeth extraction; and 3) ESC-3, more than two contiguous teeth extractions. Immediate implants were inserted in each socket, and postoperative plaque control measures were undertaken. After euthanasia, the jaw segments were evaluated for bone thickness, marginal bone loss (MBL), and bone-to-implant contact (BIC) using microcomputed tomography. The mean buccal bone thickness (P <0.05) and MBL (P <0.05) was compromised in jaws in ESC-3 compared to those in ESC-1 and ESC-2. The BIC was significantly higher among jaws in ESC-1 compared to those in ESC-2 and ESC-3 (P <0.05). There was no significant difference in the buccal bone thickness, MBL, and BIC among the groups in the maxilla and mandible. Lingual bone remodeling did not reveal any significant differences among the groups in either jaw. Buccal bone remodeling is significantly more extensive around immediate implants placed in multiple contiguous tooth extraction sites compared to immediate implants placed in single tooth extraction sites.

  13. Retracted: Micro-computed tomography evaluation of apical transportation and centring ability of Reciproc and WaveOne systems in severely curved root canals.

    PubMed

    de Meireles, D A; de Brito, T C C A; Marques, A A F; Garrido, A D B; Garcia, L F R; Sponchiado, E C

    2015-08-01

    The following article from International Endodontic Journal, 'Micro-computed tomography evaluation of apical transportation and centring ability of Reciproc and WaveOne systems in severely curved root canals' by D. A. de Meireles, T. C. C. A. de Brito, A. A. F. Marques, A. D. B. Garrido, L. F. R. Garcia & E. C. Sponchiado Jr, published online on 5 February 2015 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the authors, the journal Editor in Chief, Prof. Paul Dummer, and John Wiley & Sons Ltd. The retraction has been agreed due to the use of techniques for crucial measurements in canal shaping and a lack of clarity regarding the measuring methodology. The use of inadequate measuring methodologies makes the findings of the paper invalid.

  14. Microcomputed tomography marginal fit evaluation of computer-aided design/computer-aided manufacturing crowns with different methods of virtual model acquisition.

    PubMed

    das Neves, Flavio Domingues; do Prado, Celio Jesus; Prudente, Marcel Santana; Carneiro, Thiago Almeida Prado Naves; Zancope, Karla; Davi, Leticia Resende; Mendonca, Gustavo; Cooper, Lyndon; Soares, Carlos Jose

    2015-01-01

    This in vitro study used microcomputed tomography to evaluate the marginal fit of crowns fabricated using a chairside computer-aided design/computer-aided manufacturing (CAD/CAM) system with different methods of virtual model acquisition. Crowns were fabricated to fit in a cast containing a single human premolar. Four methods of virtual model acquisition were used: Group 1 (control), digital impressioning of a typodont; Group 2, digital impressioning of a powdered typodont; Group 3, digital impressioning of a regular impression; and Group 4, digital impressioning of a master cast. Statistically significant differences were found between the marginal gap of Group 2 and the other groups (P < 0.05); no differences were found among Groups 1, 3, and 4. The results showed that crowns fabricated using the chairside CAD/CAM system exhibited significantly smaller vertical misfit when a thin layer of powder was applied over the typodont before digital impressioning.

  15. [Animal models for bone and joint disease. Assessment of bone mass, structure and strength in rat and mouse models - focus on micro-computed tomography study -].

    PubMed

    Ito, Masako

    2011-02-01

    In the assessment of quality of bone in animal models, it is required to know the differences in bone mineral density, bone structure and strength from the human bones. "Guidelines for Assessment of Bone Microstructure in Rodents Using Micro-Computed Tomography" has been published (2010 JBMR). For a good use of micro-CT for animal studies, the important items are explained in this article, (1) Imaging acquisition : sample preparation and positioning, X-ray scan conditions, voxel size/image resolution, region of interest (2) Image processing : filtration, segmentation (3) Terminology and algorithm of trabecular (bone volume fraction, trabecular number/thickness/separation, structure model index, connectivity, degree of anisotropy) and cortical (cross-sectional area, cortical thickness) bone morphometry.

  16. Root Canal Morphology and Configuration of 118 Mandibular First Molars by Means of Micro-Computed Tomography: An Ex Vivo Study.

    PubMed

    Wolf, Thomas Gerhard; Paqué, Frank; Zeller, Maximilian; Willershausen, Brita; Briseño-Marroquín, Benjamín

    2016-04-01

    The aim of this study was to investigate the root canal system morphology of the mandibular first molar by means of micro-computed tomography. The root canal configuration, foramina, and accessory canals frequency of 118 mandibular first molars were investigated by means of micro-computed tomography and 3-dimensional software imaging. A 4-digit system describes the root canal configuration from the coronal to apical thirds and the main foramina number. The most frequent root canal configurations in mesial root were 2-2-2/2 (31.4%), 2-2-1/1 (15.3%), and 2-2-2/3 (11.9%); another 24 different root canal configurations were observed in this root. A 1-1-1/1 (58.5%), 1-1-1/2 (10.2%), and 16 other root canal configurations were observed in the distal root. The mesiobuccal root canal showed 1-4 foramina in 24.6%, and the mesiolingual showed 1-3 foramina in 28.0%. One connecting canal between the mesial root canals was observed in 30.5% and 2 in 3.4%. The distolingual root canal showed 1-4 foramina in 23.7%, whereas a foramen in the distobuccal root canal was rarely detected (3.4%). The mesiobuccal, mesiolingual, and distolingual root canals showed at least 1 accessory canal (14.3, 10.2, and 4.2%, respectively), but the distobuccal had none. The root canal configuration of mandibular first molars varies strongly. According to our expectations, both the mesial and distal roots showed a high number of morphologic diversifications. The root canal system of the mesial root showed more root canal configuration variations, connecting and accessory canals than the distal root. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  17. Comparison of eight microcomputer dietary analysis programs with the USDA Nutrient Data Base for Standard Reference.

    PubMed

    Lee, R D; Nieman, D C; Rainwater, M

    1995-08-01

    To compare the general operating features and nutrient databases of eight microcomputer dietary analysis programs. A 3-day food record with 73 food items was entered into each program by the authors. The general operating features of the program were summarized and evaluated. The nutrient database was evaluated by comparing the nutrient analysis output with the 1993 US Department of Agriculture (USDA) Nutrient Data Base for Standard Reference (NDB), full version, release 10, for microcomputers. The programs varied in cost, number of foods and nutrients in the database, use of non-USDA data, and inputting of data for missing values. We also found differences in the quality of user manuals and help screens, ease of food entry and averaging of 3-day nutrient intake, speed of analyzing and printing results, quality and number of print/export options, and overall ease of learning and using the program. All but one of the programs were within 15% of the USDA NDB for energy, protein, total fat, and total carbohydrates. However, there was some difference in the number of other nutrients and food components varying more than 15% from the USDA NDB. These differences occurred because of variations in the number of food items included in each programs' database and the number of missing nutrient values in the database. Our results demonstrate the importance of carefully choosing a microcomputer dietary analysis program that is suitable to the user's specific and predetermined needs.

  18. Comparison of Apple, Epson, IBM, and Other Microcomputers for Applications in Rehabilitation Systems for Persons with Physical Handicaps. Revision D.

    ERIC Educational Resources Information Center

    Vanderheiden, Gregg C.

    The paper analyzes major microcomputer systems and their use in rehabilitative systems for persons with physical handicaps. Four categories of microcomputers are addressed: systems designed for home or school with emphasis on low cost, recreation, and educational software; general purpose microcomputers with applications in a large number of…

  19. 3D analysis of bone formation around titanium implants using micro-computed tomography (μCT)

    NASA Astrophysics Data System (ADS)

    Bernhardt, Ricardo; Scharnweber, Dieter; Müller, Bert; Beckmann, Felix; Goebbels, Jürgen; Jansen, John; Schliephake, Henning; Worch, Hartmut

    2006-08-01

    The quantitative analysis of bone formation around biofunctionalised metallic implants is an important tool for the further development of implants with higher success rates. This is, nowadays, especially important in cases of additional diseases like diabetes or osteoporosis. Micro computed tomography (μCT), as non-destructive technique, offers the possibility for quantitative three-dimensional recording of bone close to the implant's surface with micrometer resolution, which is the range of the relevant bony structures. Within different animal models using cylindrical and screw-shaped Ti6Al4V implants we have compared visualization and quantitative analysis of newly formed bone by the use of synchrotron-radiation-based CT-systems in comparison with histological findings. The SRμCT experiments were performed at the beamline BW 5 (HASYLAB at DESY, Hamburg, Germany; at the BAMline (BESSY, Berlin, Germany). For the experiments, PMMA-embedded samples were prepared with diameters of about 8 mm, which contain in the center the implant surrounded by the bony tissue. To (locally) quantify the bone formation, models were developed and optimized. The comparison of the results obtained by SRμCT and histology demonstrates the advantages and disadvantages of both approaches, although the bone formation values for the different biofunctionalized implants are identical within the error bars. SRμCT allows the clear identification of fully mineralized bone around the different titanium implants. As hundreds of virtual slices were easily generated for the individual samples, the quantification and interactive bone detection led to conclusions of high precision and statistical relevance. In this way, SRμCT in combination with interactive data analysis is proven to be more significant with respect to classical histology.

  20. Adjunctive Steps for Disinfection of the Mandibular Molar Root Canal System: A Correlative Bacteriologic, Micro-Computed Tomography, and Cryopulverization Approach.

    PubMed

    Alves, Flávio R F; Andrade-Junior, Carlos V; Marceliano-Alves, Marília F; Pérez, Alejandro R; Rôças, Isabela N; Versiani, Marco A; Sousa-Neto, Manoel D; Provenzano, José C; Siqueira, José F

    2016-11-01

    This study evaluated the disinfecting ability of chemomechanical preparation with rotary nickel-titanium instruments, followed by 2 distinct adjunctive procedures in the root canals of extracted mandibular molars by means of a correlative analytical approach. Twenty-two extracted mandibular molars were selected and anatomically matched between groups on the basis of micro-computed tomographic analysis. In the first phase of the experiment, root canals were contaminated with Enterococcus faecalis and subjected to chemomechanical preparation with BT RaCe instruments and 2.5% NaOCl irrigation. Then either XP-Endo Finisher instrument or passive ultrasonic irrigation was used to supplement disinfection. Micro-computed tomography was used to show whether the percentage of unprepared areas correlated to bacterial counts. In the second phase, the same teeth were contaminated once again, and the adjunctive procedures were used. Samples from the isthmus area of mesial roots and the apical 5-mm fragment of distal roots were obtained by cryopulverization. Samples taken before and after treatment steps in both phases were evaluated by quantitative polymerase chain reaction and statistically analyzed. In phase 1, preparation in both groups resulted in substantial decrease of bacterial counts (P < .001). The adjunctive approaches led to a further small bacterial reduction, which was significant for XP-Endo Finisher (P < .05). No significant differences were observed between groups for persisting bacterial counts. Correlative analysis revealed no statistically significant relationship between bacterial reduction and the percentage of unprepared areas (P > .05). In phase 2, both methods had significant antibacterial effects in the main canal, but none of them could predictably disinfect the isthmus/recess areas. Both XP-Endo Finisher and passive ultrasonic irrigation exhibited antibacterial effectiveness, but only the former caused a significant reduction in the bacterial

  1. Micro-computed tomography evaluation of marginal fit of lithium disilicate crowns fabricated by using chairside CAD/CAM systems or the heat-pressing technique.

    PubMed

    Neves, Flávio D; Prado, Célio J; Prudente, Marcel S; Carneiro, Thiago A P N; Zancopé, Karla; Davi, Letícia R; Mendonça, Gustavo; Cooper, Lyndon F; Soares, Carlos José

    2014-11-01

    No consensus exists concerning the acceptable ranges of marginal fit for lithium disilicate crowns fabricated with either heat-pressing techniques or computer-aided design and computer-aided manufacturing (CAD/CAM) systems. The purpose of the study was to evaluate with micro-computed tomography the marginal fit of lithium disilicate crowns fabricated with different chairside CAD/CAM systems (Cerec or E4D) or the heat-pressing technique. Lithium disilicate crowns were fabricated to fit an in vitro cast of a single human premolar. Three fabrication techniques were used: digital impressions with Cerec 3D Bluecam scanner with titanium dioxide powder, followed by milling from IPS e.max CAD for Cerec; digital impressions with E4D Laser scanner without powder, followed by milling from IPS e.max CAD for E4D; and fabrication from IPS e.max Press by using the lost-wax and heat-pressing techniques. Each crown was fixed to the cast and scanned with micro-computed tomography to obtain 52 images for measuring the vertical and horizontal fit. Data were statistically analyzed by 1-way ANOVA, followed by the Tukey honestly significant difference test (α=.05). The mean values of vertical misfit were 36.8 ±13.9 μm for the heat-pressing group and 39.2 ±8.7 μm for the Cerec group, which were significantly smaller values than for the E4D group at 66.9 ±31.9 μm (P=.046). The percentage of crowns with a vertical misfit <75 μm was 83.8% for Cerec and heat-pressing, whereas this value was 65% for E4D. Both types of horizontal misfit (underextended and overextended) were 49.2% for heat-pressing, 50.8% for Cerec, and 58.8% for E4D. Lithium disilicate crowns fabricated by using the Cerec 3D Bluecam scanner CAD/CAM system or the heat-pressing technique exhibited a significantly smaller vertical misfit than crowns fabricated by using an E4D Laser scanner CAD/CAM system. Copyright © 2014 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights

  2. Peri-implant osseointegration after low-level laser therapy: micro-computed tomography and resonance frequency analysis in an animal model.

    PubMed

    Mayer, Luciano; Gomes, Fernando Vacilotto; de Oliveira, Marília Gerhardt; de Moraes, João Feliz Duarte; Carlsson, Lennart

    2016-12-01

    The purpose of the present study is to evaluate the effects of low-level laser therapy on the osseointegration process by comparing resonance frequency analysis measurements performed at implant placement and after 30 days and micro-computed tomography images in irradiated vs nonirradiated rabbits. Fourteen male New Zealand rabbits were randomly divided into two groups of seven animals each, one control group (nonirradiated animals) and one experimental group that received low-level laser therapy (Thera Lase®, aluminum-gallium-arsenide laser diode, 10 J per spot, two spots per session, seven sessions, 830 nm, 50 mW, CW, Ø 0.0028 cm(2)). The mandibular left incisor was surgically extracted in all animals, and one osseointegrated implant was placed immediately afterward (3.25ø × 11.5 mm; NanoTite, BIOMET 3i). Resonance frequency analysis was performed with the Osstell® device at implant placement and at 30 days (immediately before euthanasia). Micro-computed tomography analyses were then conducted using a high-resolution scanner (SkyScan 1172 X-ray Micro-CT) to evaluate the amount of newly formed bone around the implants. Irradiated animals showed significantly higher implant stability quotients at 30 days (64.286 ± 1.596; 95 % confidence interval (CI) 60.808-67.764) than controls (56.357 ± 1.596; 95 %CI 52.879-59.835) (P = .000). The percentage of newly formed bone around the implants was also significantly higher in irradiated animals (75.523 ± 8.510; 95 %CI 61.893-89.155) than in controls (55.012 ± 19.840; 95 %CI 41.380-68.643) (P = .027). Laser therapy, based on the irradiation protocol used in this study, was able to provide greater implant stability and increase the volume of peri-implant newly formed bone, indicating that laser irradiation effected an improvement in the osseointegration process.

  3. "Speaking" Microcomputer

    NASA Technical Reports Server (NTRS)

    Mandy, C.; Annerton, J.

    1986-01-01

    Microcomputer system allows blind person to use portable computer and communicate with remote mainframe computer. System prepares data for transmission to mainframe, translates data transmitted from mainframe for its own use, and converts data ordinarily displayed on its video screen into synthesized speech.

  4. "Speaking" Microcomputer

    NASA Technical Reports Server (NTRS)

    Mandy, C.; Annerton, J.

    1986-01-01

    Microcomputer system allows blind person to use portable computer and communicate with remote mainframe computer. System prepares data for transmission to mainframe, translates data transmitted from mainframe for its own use, and converts data ordinarily displayed on its video screen into synthesized speech.

  5. Microcomputer Guide.

    ERIC Educational Resources Information Center

    Fors, George, Ed.

    Designed for use by school districts introducing computer mathematics into the curriculum, this manual provides guidelines for selecting a microcomputer system, as well as objectives and an outline for an introductory course in computer programming. Also presented are topics for computer applications in science, mathematics, chemistry, and…

  6. Inside Microcomputers.

    ERIC Educational Resources Information Center

    Frederick, Franz J.

    1982-01-01

    The internal processes of microcomputer functioning are explained. Components include: (1) a central processing unit; (2) memories which store programs and data; (3) a clock which determines the order in which a computer performs its operations; (4) a bus consisting of receptacles for additional installations; (5) interfaces which connect the…

  7. Microcomputer Guide.

    ERIC Educational Resources Information Center

    Fors, George, Ed.

    Designed for use by school districts introducing computer mathematics into the curriculum, this manual provides guidelines for selecting a microcomputer system, as well as objectives and an outline for an introductory course in computer programming. Also presented are topics for computer applications in science, mathematics, chemistry, and…

  8. Comparative study of chitosan/fibroin–hydroxyapatite and collagen membranes for guided bone regeneration in rat calvarial defects: micro-computed tomography analysis

    PubMed Central

    Song, Jae Min; Shin, Sang Hun; Kim, Yong Deok; Lee, Jae Yeol; Baek, Young Jae; Yoon, Sang Yong; Kim, Hong Sung

    2014-01-01

    This study aimed to utilize micro-computed tomography (micro-CT) analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin–hydroxyapatite (CFB–HAP) or collagen (Bio-Gide) membranes. Fifty-four (54) rats were studied. A circular bony defect (8 mm diameter) was formed in the centre of the calvaria using a trephine bur. The CFB–HAP membrane was prepared by thermally induced phase separation. In the experimental group (n=18), the CFB–HAP membrane was used to cover the bony defect, and in the control group (n=18), a resorbable collagen membrane (Bio-Gide) was used. In the negative control group (n=18), no membrane was used. In each group, six animals were euthanized at 2, 4 and 8 weeks after surgery. The specimens were then analysed using micro-CT. There were significant differences in bone volume (BV) and bone mineral density (BMD) (P<0.05) between the negative control group and the membrane groups. However, there were no significant differences between the CFB–HAP group and the collagen group. We concluded that the CFB–HAP membrane has significant potential as a guided bone regeneration (GBR) membrane. PMID:24722582

  9. Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping

    PubMed Central

    Hatzer-Grubwieser, P.; Bauer, C.; Parson, W.; Unterberger, S. H.; Kuhn, V.; Pemberger, N.; Pallua, Anton K.; Recheis, W.; Lackner, R.; Stalder, R.; Pallua, J. D.

    2015-01-01

    In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach. PMID:25878731

  10. Three-dimensional X-ray microcomputed tomography of carbonates and biofilm on operated cathode in single chamber microbial fuel cell.

    PubMed

    Santini, Maurizio; Guilizzoni, Manfredo; Lorenzi, Massimo; Atanassov, Plamen; Marsili, Enrico; Fest-Santini, Stephanie; Cristiani, Pierangela; Santoro, Carlo

    2015-09-10

    Power output limitation is one of the main concerns that need to be addressed for full-scale applications of the microbial fuel cell technology. Fouling and biofilm growth on the cathode of single chamber microbial fuel cells (SCMFC) affects their performance in long-term operation with wastewater. In this study, the authors report the power output and cathode polarization curves of a membraneless SCMFC, fed with raw primary wastewater and sodium acetate for over 6 months. At the end of the experiment, the whole cathode surface is analyzed through X-ray microcomputed tomography (microCT), scanning electron microscopy, and energy-dispersive X-ray spectroscopy (EDX) to characterize the fouling layer and the biofilm. EDX shows the distribution of Ca, Na, K, P, S, and other elements on the two faces of the cathode. Na-carbonates and Ca-carbonates are predominant on the air (outer) side and the water (inner) side, respectively. The three-dimensional reconstruction by X-ray microCT shows biofilm spots unevenly distributed above the Ca-carbonate layer on the inner (water) side of the cathode. These results indicate that carbonates layer, rather than biofilm, might lower the oxygen reduction reaction rate at the cathode during long-term SCMFC operation.

  11. Micro-computed tomography evaluation of the glenoid fossa and mandibular condyle bone after bilateral vertical ramus mandibular distraction in a canine model.

    PubMed

    Sant'Anna, Eduardo Franzotti; Gomez, David F; Sumner, Dale R; Williams, James M; Figueroa, Alvaro A; Ostric, Srdjan A; Theodoru, Spero; Polley, John W

    2006-01-01

    The aim of this study was to quantify bone microarchitecture within the glenoid fossa and mandibular condyle following mandibular distraction osteogenesis. Eight 6- to 9-month-old male beagle dogs underwent bilateral vertical mandibular distraction with semiburied distractors (12 days of distraction at 1 mm per day). One unoperated animal served as control. After distraction the animals were divided into two groups (N = 4) and killed after 1 or 2 months of consolidation. Three-dimensional trabecular architecture was analyzed by micro-computed tomography (muCT). At both sites the overall trends were similar. In the glenoid fossa, there was decreased bone volume, trabecular number, and connectivity density and increased trabecular separation at 1 month and decreased trabecular thickness and increased structure model index compared with the control (P < 0.05). In the mandibular condyle, there was decreased bone volume, trabecular number, and connectivity density at both 1 and 2 months, with decreased trabecular thickness and increased structure model index at 2 months only compared with the control (P < 0.05). The bone became less dense and more rodlike. These bone changes are similar to those seen by the effects of aging or impaired normal function. Thus, in the short term, changes occur in the bone microstructure of the glenoid fossa and mandibular condyle after vertical mandibular ramus distraction in the canine model.

  12. Micro-computed tomography evaluation of the glenoid fossa and mandibular condyle bone after bilateral vertical ramus mandibular distraction in a canine model.

    PubMed

    Sant'Anna, Eduardo Franzotti; Gomez, David F; Sumner, Dale R; Williams, James M; Figueroa, Alvaro A; Ostric, Srdjan A; Theodoru, Spero; Polley, John W

    2006-05-01

    The aim of this study was to quantify bone microarchitecture within the glenoid fossa and mandibular condyle following mandibular distraction osteogenesis. Eight 6- to 9-month-old male beagle dogs underwent bilateral vertical mandibular distraction with semiburied distractors (12 days of distraction at 1 mm per day). One unoperated animal served as control. After distraction the animals were divided into two groups (N = 4) and killed after 1 or 2 months of consolidation. Three-dimensional trabecular architecture was analyzed by micro-computed tomography (microCT). At both sites the overall trends were similar. In the glenoid fossa, there was decreased bone volume, trabecular number, and connectivity density and increased trabecular separation at 1 month and decreased trabecular thickness and increased structure model index compared with the control (P < 0.05). In the mandibular condyle, there was decreased bone volume, trabecular number, and connectivity density at both 1 and 2 months, with decreased trabecular thickness and increased structure model index at 2 months only compared with the control (P < 0.05). The bone became less dense and more rodlike. These bone changes are similar to those seen by the effects of aging or impaired normal function. Thus, in the short term, changes occur in the bone microstructure of the glenoid fossa and mandibular condyle after vertical mandibular ramus distraction in the canine model.

  13. Heidelberg-mCT-Analyzer: a novel method for standardized microcomputed-tomography-guided evaluation of scaffold properties in bone and tissue research

    PubMed Central

    Weis, Christian; Hoellig, Melanie; Swing, Tyler; Schmidmaier, Gerhard; Weber, Marc-André; Stiller, Wolfram; Kauczor, Hans-Ulrich; Moghaddam, Arash

    2015-01-01

    Bone tissue engineering and bone scaffold development represent two challenging fields in orthopaedic research. Micro-computed tomography (mCT) allows non-invasive measurement of these scaffolds’ properties in vivo. However, the lack of standardized mCT analysis protocols and, therefore, the protocols’ user-dependency make interpretation of the reported results difficult. To overcome these issues in scaffold research, we introduce the Heidelberg-mCT-Analyzer. For evaluation of our technique, we built 10 bone-inducing scaffolds, which underwent mCT acquisition before ectopic implantation (T0) in mice, and at explantation eight weeks thereafter (T1). The scaffolds’ three-dimensional reconstructions were automatically segmented using fuzzy clustering with fully automatic level-setting. The scaffold itself and its pores were then evaluated for T0 and T1. Analysing the scaffolds’ characteristic parameter set with our quantification method showed bone formation over time. We were able to demonstrate that our algorithm obtained the same results for basic scaffold parameters (e.g. scaffold volume, pore number and pore volume) as other established analysis methods. Furthermore, our algorithm was able to analyse more complex parameters, such as pore size range, tissue mineral density and scaffold surface. Our imaging and post-processing strategy enables standardized and user-independent analysis of scaffold properties, and therefore is able to improve the quantitative evaluations of scaffold-associated bone tissue-engineering projects. PMID:26716008

  14. External and internal bone micro-architecture in normal and Kienböck's lunates: a whole-bone micro-computed tomography study.

    PubMed

    Low, Stephanie C; Bain, Gregory I; Findlay, David M; Eng, Kevin; Perilli, Egon

    2014-06-01

    Kienböck's disease is idiopathic osteonecrosis of the lunate, leading to its fracture and collapse. This study compares internal and external bone micro-architecture of normal and fractured lunates (Kienböck's), by using high-resolution three-dimensional (3D) micro-computed tomography (micro-CT) on the whole bone of the two lunate types, and histology. Fractured Kienböck-diseased lunates were obtained from patients undergoing proximal-row-carpectomy, while normal cadaveric lunates served as controls. 3D-micro-CT-imaging of control lunates revealed an encircling cortex surrounding trabecular bone. Trabeculae were arranged in a radial pattern, spanning from the distal to the proximal subchondral plate. Kienböck's lunates exhibited clear fracture lines, with fragmented bone, both proximally and distally, in areas the radially-patterned trabeculae and enveloping cortex were absent, producing height loss. In trabecular bone, Kienböck's lunates revealed increased bone volume fraction, trabecular thickness and number, and decreased trabecular separation and structure model index. Histologically, Kienböck's lunates revealed osteonecrosis, as well as remodeling fronts with osteoblasts and osteoid surrounding bone marrow. Whole-bone high-resolution 3D examination of normal and Kienböck's diseased lunates contributes to a better understanding of micro-architectural changes occurring in the pathology.

  15. Evaluation of in-vivo measurement errors associated with micro-computed tomography scans by means of the bone surface distance approach.

    PubMed

    Lu, Yongtao; Boudiffa, Maya; Dall'Ara, Enrico; Bellantuono, Ilaria; Viceconti, Marco

    2015-11-01

    In vivo micro-computed tomography (µCT) scanning is an important tool for longitudinal monitoring of the bone adaptation process in animal models. However, the errors associated with the usage of in vivo µCT measurements for the evaluation of bone adaptations remain unclear. The aim of this study was to evaluate the measurement errors using the bone surface distance approach. The right tibiae of eight 14-week-old C57BL/6 J female mice were consecutively scanned four times in an in vivo µCT scanner using a nominal isotropic image voxel size (10.4 µm) and the tibiae were repositioned between each scan. The repeated scan image datasets were aligned to the corresponding baseline (first) scan image dataset using rigid registration and a region of interest was selected in the proximal tibia metaphysis for analysis. The bone surface distances between the repeated and the baseline scan datasets were evaluated. It was found that the average (±standard deviation) median and 95th percentile bone surface distances were 3.10 ± 0.76 µm and 9.58 ± 1.70 µm, respectively. This study indicated that there were inevitable errors associated with the in vivo µCT measurements of bone microarchitecture and these errors should be taken into account for a better interpretation of bone adaptations measured with in vivo µCT. Copyright © 2015 IPEM. Published by Elsevier Ltd. All rights reserved.

  16. Influence of low-intensity pulsed ultrasound on osteogenic tissue regeneration in a periodontal injury model: X-ray image alterations assessed by micro-computed tomography.

    PubMed

    Wang, Yunji; Chai, Zhaowu; Zhang, Yuanyuan; Deng, Feng; Wang, Zhibiao; Song, Jinlin

    2014-08-01

    This study was conducted to evaluate, with micro-computed tomography, the influence of low-intensity pulsed ultrasound on wound-healing in periodontal tissues. Periodontal disease with Class II furcation involvement was surgically produced at the bilateral mandibular premolars in 8 adult male beagle dogs. Twenty-four teeth were randomly assigned among 4 groups (G): G1, periodontal flap surgery; G2, periodontal flap surgery+low-intensity pulsed ultrasound (LIPUS); G3, guided tissue regeneration (GTR) surgery; G4, GTR surgery plus LIPUS. The affected area in the experimental group was exposed to LIPUS. At 6 and 8weeks, the X-ray images of regenerated teeth were referred to micro-CT scanning for 3-D measurement. Bone volume (BV), bone surface (BS), and number of trabeculae (Tb) in G2 and G4 were higher than in G1 and G3 (p<0.05). BV, BS, and Tb.N of the GTR+LIPUS group were higher than in the GTR group. BV, BS, and Tb.N of the LIPUS group were higher than in the periodontal flap surgery group. LIPUS irradiation increased the number, volume, and area of new alveolar bone trabeculae. LIPUS has the potential to promote the repair of periodontal tissue, and may work effectively if combined with GTR. Copyright © 2014 Elsevier B.V. All rights reserved.

  17. Post-mortem interval estimation of human skeletal remains by micro-computed tomography, mid-infrared microscopic imaging and energy dispersive X-ray mapping.

    PubMed

    Longato, S; Wöss, C; Hatzer-Grubwieser, P; Bauer, C; Parson, W; Unterberger, S H; Kuhn, V; Pemberger, N; Pallua, Anton K; Recheis, W; Lackner, R; Stalder, R; Pallua, J D

    2015-04-07

    In this study different state-of-the-art visualization methods such as micro-computed tomography (micro-CT), mid-infrared (MIR) microscopic imaging and energy dispersive X-ray (EDS) mapping were evaluated to study human skeletal remains for the determination of the post-mortem interval (PMI). PMI specific features were identified and visualized by overlaying molecular imaging data and morphological tissue structures generated by radiological techniques and microscopic images gained from confocal microscopy (Infinite Focus (IFM)). In this way, a more distinct picture concerning processes during the PMI as well as a more realistic approximation of the PMI were achieved. It could be demonstrated that the gained result in combination with multivariate data analysis can be used to predict the Ca/C ratio and bone volume (BV) over total volume (TV) for PMI estimation. Statistical limitation of this study is the small sample size, and future work will be based on more specimens to develop a screening tool for PMI based on the outcome of this multidimensional approach.

  18. RooTrak: automated recovery of three-dimensional plant root architecture in soil from x-ray microcomputed tomography images using visual tracking.

    PubMed

    Mairhofer, Stefan; Zappala, Susan; Tracy, Saoirse R; Sturrock, Craig; Bennett, Malcolm; Mooney, Sacha J; Pridmore, Tony

    2012-02-01

    X-ray microcomputed tomography (μCT) is an invaluable tool for visualizing plant root systems within their natural soil environment noninvasively. However, variations in the x-ray attenuation values of root material and the overlap in attenuation values between roots and soil caused by water and organic materials represent major challenges to data recovery. We report the development of automatic root segmentation methods and software that view μCT data as a sequence of images through which root objects appear to move as the x-y cross sections are traversed along the z axis of the image stack. Previous approaches have employed significant levels of user interaction and/or fixed criteria to distinguish root and nonroot material. RooTrak exploits multiple, local models of root appearance, each built while tracking a specific segment, to identify new root material. It requires minimal user interaction and is able to adapt to changing root density estimates. The model-guided search for root material arising from the adoption of a visual-tracking framework makes RooTrak less sensitive to the natural ambiguity of x-ray attenuation data. We demonstrate the utility of RooTrak using μCT scans of maize (Zea mays), wheat (Triticum aestivum), and tomato (Solanum lycopersicum) grown in a range of contrasting soil textures. Our results demonstrate that RooTrak can successfully extract a range of root architectures from the surrounding soil and promises to facilitate future root phenotyping efforts.

  19. Three-Dimensional Visualization of Bioactive Glass-Bone Integration in a Rabbit Tibia Model Using Synchrotron X-Ray Microcomputed Tomography

    PubMed Central

    Huang, Wenhai; Jia, Weitao; Rahaman, Mohamed N.; Liu, Xin; Tomsia, Antoni P.

    2011-01-01

    Synchrotron X-ray microcomputed tomography (SR microCT), with a micron resolution, was used to evaluate the osteoconduction and osteointegration by borate bioactive glass after implantation 12 weeks in a rabbit tibia model. The study focused on the biomaterial–bone interface. Results from SR microCT two-dimensional and three-dimensional (3D) reconstructions provided precise imaging of the biomaterial–bone integration and detailed microarchitecture of both the bone-like glass graft and the newly formed trabecular bone. Osteoconduction, the formation of new trabecular bone within a tibia defect, occurred only in the tibiae implanted with teicoplanin-loaded borate glass but not in those with teicoplanin-loaded CaSO4 beads, indicating the excellent biocompatibility of the glass implants. 3D reconstruction of the tibiae also showed the infiltration of vascular tissue in both the bioactive glass graft and the new trabecular bone. This study indicates that SR microCT can serve as a valuable complementary technique for imaging bone repair when using bioactive glass implants. PMID:21875330

  20. The ‘dance’ of life: visualizing metamorphosis during pupation in the blow fly Calliphora vicina by X-ray video imaging and micro-computed tomography

    PubMed Central

    Simonsen, Thomas J.; Martín-Vega, Daniel

    2017-01-01

    The dramatic metamorphosis from larva to adult of insect orders such as Diptera cannot usually be witnessed because it occurs within an opaque structure. For the cyclorrhaphous dipterans, such as blow flies, this structure is the puparium, formed from the larval cuticle. Here, we reveal metamorphosis within the puparium of a blow fly at higher temporal resolution than previously possible with two-dimensional time-lapse videos created using the X-ray within a micro-computed tomography scanner, imaging development at 1 min and 2 min intervals. Our studies confirm that the most profound morphological changes occur during just 0.5% of the intrapuparial period (approx. equivalent to 1.25 h at 24°C) and demonstrate the significant potential of this technique to complement other methods for the study of developmental changes, such as hormone control and gene expression. We hope this will stimulate a renewed interest among students and researchers in the study of morphology and its astonishing transformation engendered by metamorphosis. PMID:28280573

  1. Comparative study of chitosan/fibroin-hydroxyapatite and collagen membranes for guided bone regeneration in rat calvarial defects: micro-computed tomography analysis.

    PubMed

    Song, Jae Min; Shin, Sang Hun; Kim, Yong Deok; Lee, Jae Yeol; Baek, Young Jae; Yoon, Sang Yong; Kim, Hong Sung

    2014-06-01

    This study aimed to utilize micro-computed tomography (micro-CT) analysis to compare new bone formation in rat calvarial defects using chitosan/fibroin-hydroxyapatite (CFB-HAP) or collagen (Bio-Gide) membranes. Fifty-four (54) rats were studied. A circular bony defect (8 mm diameter) was formed in the centre of the calvaria using a trephine bur. The CFB-HAP membrane was prepared by thermally induced phase separation. In the experimental group (n=18), the CFB-HAP membrane was used to cover the bony defect, and in the control group (n=18), a resorbable collagen membrane (Bio-Gide) was used. In the negative control group (n=18), no membrane was used. In each group, six animals were euthanized at 2, 4 and 8 weeks after surgery. The specimens were then analysed using micro-CT. There were significant differences in bone volume (BV) and bone mineral density (BMD) (P<0.05) between the negative control group and the membrane groups. However, there were no significant differences between the CFB-HAP group and the collagen group. We concluded that the CFB-HAP membrane has significant potential as a guided bone regeneration (GBR) membrane.

  2. Thermal-stress analysis of ceramic laminate veneer restorations with different incisal preparations using micro-computed tomography-based 3D finite element models.

    PubMed

    Celebi, Alper Tunga; Icer, Esra; Eren, Meltem Mert; Baykasoglu, Cengiz; Mugan, Ata; Yildiz, Esra

    2017-11-01

    Main objective of this study is to investigate the thermal behavior of ceramic laminate veneer restorations of the maxillary central incisor with different incisal preparations such as butt joint and palatinal chamfer using finite element method. In addition, it is also aimed to understand the effect of different thermal loads which simulates hot and cold liquid imbibing in the mouth. Three-dimensional solid models of the sound tooth and prepared veneer restorations were obtained using micro-computed tomography images. Each ceramic veneer restoration was made up of ceramic, luting resin cement and adhesive layer which were generated based on the scanned images using computer-aided design software. Our solid model also included the remaining dental tissues such as periodontal ligament and surrounding cortical and spongy bones. Time-dependent linear thermal analyses were carried out to compare temperature changes and stress distributions of the sound and restored tooth models. The liquid is firstly in contact with the crown area where the maximum stresses were obtained. For the restorations, stresses on palatinal surfaces were found larger than buccal surfaces. Through interior tissues, the effect of thermal load diminished and smaller stress distributions were obtained near pulp and root-dentin regions. We found that the palatinal chamfer restoration presents comparatively larger stresses than the butt joint preparation. In addition, cold thermal loading showed larger temperature changes and stress distributions than those of hot thermal loading independent from the restoration technique. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Micro-computed tomography (μCT) as a novel method in ecotoxicology--determination of morphometric and somatic data in rainbow trout (Oncorhynchus mykiss).

    PubMed

    Brinkmann, Markus; Rizzo, Larissa Y; Lammers, Twan; Gremse, Felix; Schiwy, Sabrina; Kiessling, Fabian; Hollert, Henner

    2016-02-01

    Fish are important sentinel organisms for the assessment of water quality and play a central role in ecotoxicological research. Of particular importance to the assessment of health and fitness of fish stocks in response to environmental conditions or pollution are morphometric (e.g. Fulton's condition index) and somatic indices (e.g. hepatosomatic, and gonadosomatic index). Standard measurements of somatic indices are invasive and require, by definition, the sacrifice of examined animals, thus prohibiting longitudinal studies and relocation of animals captured in the field. As a potential solution, in the present study, we propose the use of micro-computed tomography (μCT) as imaging modality to non-invasively tomographically image rainbow trout (Oncorhynchus mykiss) exposed to different sediment suspensions. We here demonstrate that μCT can be used as a tool to reliably measure the volumes of different organs, which could then be applied as a substitute of their weights in calculation of somatic indices. To the best of our knowledge, this study is the first to report the results of μCT analyses in the context of ecotoxicological research in rainbow trout. It has the potential to greatly increase the information value of experiments conducted with fish and also to potentially reduce the number of animals required for studying temporal effects through facilitating longitudinal studies within the same individuals.

  4. Evaluation of aggregate microstructures following natural regeneration in bauxite residue as characterized by synchrotron-based X-ray micro-computed tomography.

    PubMed

    Zhu, Feng; Liao, Jiaxin; Xue, Shengguo; Hartley, William; Zou, Qi; Wu, Hao

    2016-12-15

    Bauxite residue often has poor physical conditions which impede plant growth. Native plant encroachment on a bauxite residue disposal area in Central China reveals that natural regeneration may improve its physicochemical properties. Residue samples collected from three different disposal ages were assessed to evaluate residue micromorphology and three-dimensional (3D) aggregate microstructure under natural regeneration. The residue aggregates in different disposal ages were divided in two sections: macro-aggregate (2-1mm) and micro-aggregate (0.25-0.05mm). Residue aggregate micromorphology was determined by scanning electron microscope and energy dispersive X-ray spectroscopy, and the residue aggregate microstructure was determined by synchrotron-based X-ray micro-computed tomography (SR-μCT) and image analysis techniques. Natural regeneration may improve residue aggregate stability and form a stable aggregate structure. Calcium content increased whilst sodium content decreased significantly on the surface of residue aggregates. Under natural soil-forming processes bauxite residue porosity, specific surface area, average length of paths, and average tortuosity of paths all significantly increased. This demonstrated that natural regeneration may stimulate the formation of stable aggregate structure in residues. Further understanding should focus on particle interaction forces and agglomeration mechanisms with the addition of external ameliorations. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Experimental polyethylene-hydroxyapatite carrier-based endodontic system: an in vitro study on dynamic thermomechanical properties, sealing ability, and measurements of micro-computed tomography voids.

    PubMed

    Alhashimi, Raghad A; Mannocci, Francesco; Sauro, Salvatore

    2016-06-01

    The dynamic thermomechanical properties, sealing ability, and voids formation of an experimental obturation hydroxyapatite-reinforced polyethylene (HA/PE) composite/carrier system were investigated and compared with those of a commercial system [GuttaCore (GC)]. The HA/PE system was specifically designed using a melt-extrusion process. The viscoelastic properties of HA/PE were determined using a dynamic thermomechanical analyser. Human single-rooted teeth were endodontically instrumented and obturated using HA/PE or GC systems, and then sealing ability was assessed using a fluid filtration system. In addition, micro-computed tomography (μCT) was used to quantify apparent voids within the root-canal space. The data were statistically analysed using one-way anova and post hoc tests. The HA/PE composite exhibited important modulus and damping changes with an increase of temperature. The HA/PE system was more flexible than GC as the modulus of GC appeared to be significantly higher than that of HA/PE as a result of the high positive glass transition temperature (Tg ). However, HA/PE and GC presented similar sealing abilities. In conclusion, because sealing ability and voids formation were comparable between the tested materials, the experimental HA/PE system may be considered a suitable alternative material for root-canal obturation. Moreover, HA/PE possesses specific viscoelastic behaviour and lower melting points, which may facilitate root-canal retreatments. © 2016 Eur J Oral Sci.

  6. The effects of dental pulp stem cells on bone regeneration in rat calvarial defect model: micro-computed tomography and histomorphometric analysis.

    PubMed

    Asutay, Fatih; Polat, Serkan; Gül, Mehmet; Subaşı, Cansu; Kahraman, Sevil Altundağ; Karaöz, Erdal

    2015-12-01

    Stem cell therapies may be applicable to all fields of medicine, including craniomaxillofacial surgery. Dental pulp stem cells also have significant osteogenic properties. This study aimed to evaluate the influence of dental pulp stem cells on bone regeneration and to ascertain whether or not there was any superiority over traditional methods. In this study, 15 non-immunodeficient Wistar albino rats were used. The rats were divided into three groups: (1) untreated control group; (2) hydroxyapatite tri-calcium-phosphate (HA/TCP) paste; (3) human dental pulp derived stem cells (DPSC) mixed with HA/TCP paste (HA/TCP+DSPC group, n=10). Two symmetrical full-thickness cranial defects were created on each parietal region (10 defects for each group). The animals were sacrificed 8 weeks post-surgery and samples were analyzed by microcomputer tomography (μ-CT) and histomorphometry. The calcification rate and bone mineral density (BMD) values in Group 3 were found to be significantly higher than in the other two groups. Radiographically, bone regeneration was greater in Group 2 compared with the control group. However, there was no significant difference between Groups 2 and 1 in respect of histological analysis. According to the results of the present study, DPSCs may be a suitable factor for bone tissue engineering because they can be easily obtained and differentiate into bone cells. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. Correlation of mechanical properties within the equine third metacarpal with trabecular bending and multi-density micro-computed tomography data.

    PubMed

    Leahy, P Devin; Smith, Barbara S; Easton, Katrina L; Kawcak, Chris E; Eickhoff, Jens C; Shetye, Snehal S; Puttlitz, Christian M

    2010-04-01

    Computed tomography (CT) data can be employed with respect to determining mechanical properties and has been used to predict parameters such as elastic modulus, yield strength, and ultimate strength of intact bone. Micro-computed tomography (muCT) possesses the resolution capable of detecting apparent bone density in extremely local regions and can characterize the trabecular structure. It has been asserted that this micro-structure is susceptible to micro-buckling and bending, which has a controversial role in predicting the global mechanical properties of bone. The current study measured the mechanical properties of relatively high apparent density bone from the equine distal third metacarpal. The mechanical properties were correlated with trabecular morphology parameters and apparent densities of localized regions obtained with muCT. These data were used to test two hypotheses: (1) accounting for trabecular bending using trabecular morphology parameters would provide better global mechanical property predictions than using only apparent density, and (2) regions of low apparent density dominate the overall mechanical behavior and provide greater correlation to the measured mechanical properties than regions of high apparent density. The data indicated that accounting for trabecular bending with morphological parameters resulted in stronger correlations to mechanical properties than correlations that relied only on apparent density (r2= 0.91 versus r2= 0.81). Low apparent density regions were more strongly correlated with mechanical properties than high apparent density regions (r2= 0.85 versus r2= 0.77), demonstrating the importance of selecting appropriate regions when attempting to predict mechanical properties from CT data.

  8. Novel fusion for hybrid optical/microcomputed tomography imaging based on natural light surface reconstruction and iterated closest point

    NASA Astrophysics Data System (ADS)

    Ning, Nannan; Tian, Jie; Liu, Xia; Deng, Kexin; Wu, Ping; Wang, Bo; Wang, Kun; Ma, Xibo

    2014-02-01

    In mathematics, optical molecular imaging including bioluminescence tomography (BLT), fluorescence tomography (FMT) and Cerenkov luminescence tomography (CLT) are concerned with a similar inverse source problem. They all involve the reconstruction of the 3D location of a single/multiple internal luminescent/fluorescent sources based on 3D surface flux distribution. To achieve that, an accurate fusion between 2D luminescent/fluorescent images and 3D structural images that may be acquired form micro-CT, MRI or beam scanning is extremely critical. However, the absence of a universal method that can effectively convert 2D optical information into 3D makes the accurate fusion challengeable. In this study, to improve the fusion accuracy, a new fusion method for dual-modality tomography (luminescence/fluorescence and micro-CT) based on natural light surface reconstruction (NLSR) and iterated closest point (ICP) was presented. It consisted of Octree structure, exact visual hull from marching cubes and ICP. Different from conventional limited projection methods, it is 360° free-space registration, and utilizes more luminescence/fluorescence distribution information from unlimited multi-orientation 2D optical images. A mouse mimicking phantom (one XPM-2 Phantom Light Source, XENOGEN Corporation) and an in-vivo BALB/C mouse with implanted one luminescent light source were used to evaluate the performance of the new fusion method. Compared with conventional fusion methods, the average error of preset markers was improved by 0.3 and 0.2 pixels from the new method, respectively. After running the same 3D internal light source reconstruction algorithm of the BALB/C mouse, the distance error between the actual and reconstructed internal source was decreased by 0.19 mm.

  9. Laboratory Microcomputing

    PubMed Central

    York, William B.

    1984-01-01

    Microcomputers will play a major role in the laboratory, not only in the calculation and interpretation of clinical test data, but also will have an increasing place of importance in the management of laboratory resources in the face of the transition from revenue generating to the cost center era. We will give you a glimpse of what can be accomplished with the management data already collected by many laboratories today when the data are processed into meaningful reports.

  10. TEC Measurements for GPS Comparisons and Ionospheric Tomography

    DTIC Science & Technology

    1999-01-01

    TEC MEASUREMENTS FOR GPS COMPARISONS AND IONOSPHERIC TOMOGRAPHY by L Kersley, S E Pryse , N Lunt, D G Jones and IK Walker Department of Physics...1975. Kersley, L., S. E. Pryse , I. K.Walker, J. A. T. Heaton, C. N. Mitchell, M. J. Williams and C. A. Willson, Imaging of electron density troughs by...ROLE OF RADIO TOMOGRAPHY IN MONITORING THE NEAR-EARTH SPACE ENVIRONMENT Cathryn N. Mitchell \\ L. Kersley \\ S. E. Pryse \\ I. K. Walkerl and P. S

  11. Microcomputers in the Classroom

    ERIC Educational Resources Information Center

    Price, Camille C.

    1978-01-01

    The definition of a microcomputer along with examples and resource information for such systems, the advantages of microcomputer kits, and the value of the microcomputers to the student are discussed. (MN)

  12. Microcomputers in the Classroom

    ERIC Educational Resources Information Center

    Price, Camille C.

    1978-01-01

    The definition of a microcomputer along with examples and resource information for such systems, the advantages of microcomputer kits, and the value of the microcomputers to the student are discussed. (MN)

  13. Micro-computed tomography-based three-dimensional kinematic analysis during lateral bending for spinal fusion assessment in a rat posterolateral lumbar fusion model.

    PubMed

    Yamaguchi, Tomonori; Inoue, Nozomu; Sah, Robert L; Lee, Yu-Po; Taborek, Alexander P; Williams, Gregory M; Moseley, Timothy A; Bae, Won C; Masuda, Koichi

    2014-07-01

    Rat posterolateral lumbar fusion (PLF) models have been used to assess the safety and effectiveness of new bone substitutes and osteoinductive growth factors using palpation, radiography, micro-computed tomography (μCT), and histology as standard methods to evaluate spinal fusion. Despite increased numbers of PLF studies involving alternative bone substitutes and growth factors, the quantitative assessment of treatment efficacy during spinal motion has been limited. The purpose of this study was to evaluate the effect of spinal fusion on lumbar spine segment stability during lateral bending using a μCT-based three-dimensional (3D) kinematic analysis in the rat PLF model. Fourteen athymic male rats underwent PLF surgery at L4/5 and received bone grafts harvested from the ilium and femurs of syngeneic rats (Isograft, n=7) or no graft (Sham, n=7). At 8 weeks after the PLF surgery, spinal fusion was assessed by manual palpation, plain radiography, μCT, and histology. To determine lumbar segmental motions at the operated level during lateral bending, 3D kinematic analysis was performed. The Isograft group, but not the Sham group, showed spinal fusion on manual palpation (6/7), solid fusion mass in radiographs (6/7), as well as bone bridging in μCT and histological images (5/7). Compared to the Sham group, the Isograft group revealed limited 3D lateral bending angular range of motion and lateral translation during lateral bending at the fused segment where disc height narrowing was observed. This μCT-based 3D kinematic analysis can provide a quantitative assessment of spinal fusion in a rat PLF model to complement current gold standard methods used for efficacy assessment of new therapeutic approaches.

  14. A micro-computed tomography study of the root canal morphology of the mandibular first premolar in a population from southwestern China.

    PubMed

    Liu, Na; Li, Xiangjie; Liu, Ning; Ye, Lijun; An, Jianping; Nie, Xin; Liu, Luchuan; Deng, Manjing

    2013-04-01

    This study aimed to investigate the root canal morphology of mandibular first premolar teeth in a population from southwestern China by micro-computed tomography (micro-CT). Human mandibular first premolars (115) were selected and prepared for micro-CT analysis with a slice thickness of 30 μm. Details of root canal orifices, canals, accessory canals, apical foramina-apical delta intercanal communication, loops and isthmuses, and mesial invagination were analyzed from reconstructed three-dimensional (3D) images. Canal patterns categorized according to the classification defined by Vertucci (Endod Top 10:3-29, 2005) as types I (65.2%), III (2.6%), V (22.6%), and VII were identified (0.9%). Accessory canals were present in 35.7% of the samples and were predominantly located in the apical third of the root. A single apical foramen was observed in 50.4% of the samples and two or three foramina in 28.7% and 14.8%, respectively. Apical delta was identified in 6.1% of the samples and the prevalence of intercanal communication and loops was 3.5% and 7%, respectively. Mesial invagination of the root was identified in 27.8% of the samples, the majority of which contained multiple canals. The data obtained in this study revealed complex root morphology with high prevalence of multiple canals, more than half of which exhibited type I canal patterns. Micro-CT was used as a noninvasive technique for 3D investigation of root canal morphology in the mandibular first premolars of a population from southwestern China. Furthermore, data obtained revealed complex anatomy of various types.

  15. Deer bone extract suppresses articular cartilage damage induced by monosodium iodoacetate in osteoarthritic rats: an in vivo micro-computed tomography study.

    PubMed

    Lee, Hyunji; Park, Yooheon; Ahn, Chang Won; Park, Soo Hyun; Jung, Eun Young; Suh, Hyung Joo

    2014-06-01

    We evaluated the anti-osteoarthritic effects of deer bone extract on articular cartilage damage by using micro-computed tomography (micro-CT) in monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in rats. Male Wistar rats (6 weeks of age) were randomly divided into 5 groups (10 rats/group): sham control (SC; PBS injection+PBS 1 mL treatment); negative control (NC; MIA injection+PBS 1 mL treatment); positive control (PC; MIA injection+250 mg/kg glucosamine sulfate/chondroitin sulfate mixture treatment); low dose (LDB; MIA injection+250 mg/kg deer bone extract treatment); and high dose (HDB; MIA injection+500 mg/kg deer bone extract treatment). After 50 days of treatment, we observed that the administration of deer bone extract protected against bone destruction and reduced the number of erosion lacunae. When deer bone extract was administered, the trabecular thickness distribution (Tb.Th) (LDB: 75.9 μm, HDB: 80.7 μm vs. NC: 48.0 μm) and the trabecular bone volume fraction ratio (BV/TV) (LDB: 43.8%, HDB: 48.2% vs. NC: 39.1%) were significantly restored. Additionally, the trabecular separation (Tb.Sp) increase caused by MIA was decreased significantly with the administration of deer bone extract (LDB: 73.4 μm, HDB: 81.2 μm vs. NC: 112.0 μm). We concluded that the oral administration of deer bone extract effectively relieved the morphological changes induced by MIA injection in an animal model.

  16. Sine Systemate Chaos? A Versatile Tool for Earthworm Taxonomy: Non-Destructive Imaging of Freshly Fixed and Museum Specimens Using Micro-Computed Tomography

    PubMed Central

    Fernández, Rosa; Kvist, Sebastian; Lenihan, Jennifer; Giribet, Gonzalo; Ziegler, Alexander

    2014-01-01

    In spite of the high relevance of lumbricid earthworms (‘Oligochaeta’: Lumbricidae) for soil structure and functioning, the taxonomy of this group of terrestrial invertebrates remains in a quasi-chaotic state. Earthworm taxonomy traditionally relies on the interpretation of external and internal morphological characters, but the acquisition of these data is often hampered by tedious dissections or restricted access to valuable and rare museum specimens. The present state of affairs, in conjunction with the difficulty of establishing primary homologies for multiple morphological features, has led to an almost unrivaled instability in the taxonomy and systematics of certain earthworm groups, including Lumbricidae. As a potential remedy, we apply for the first time a non-destructive imaging technique to lumbricids and explore the future application of this approach to earthworm taxonomy. High-resolution micro-computed tomography (μCT) scanning of freshly fixed and museum specimens was carried out using two cosmopolitan species, Aporrectodea caliginosa and A. trapezoides. By combining two-dimensional and three-dimensional dataset visualization techniques, we demonstrate that the morphological features commonly used in earthworm taxonomy can now be analyzed without the need for dissection, whether freshly fixed or museum specimens collected more than 60 years ago are studied. Our analyses show that μCT in combination with soft tissue staining can be successfully applied to lumbricid earthworms. An extension of the approach to other families is poised to strengthen earthworm taxonomy by providing a versatile tool to resolve the taxonomic chaos currently present in this ecologically important, but taxonomically neglected group of terrestrial invertebrates. PMID:24837238

  17. Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers

    PubMed Central

    Wang, Chun-Neng; Hsu, Hao-Chun; Wang, Cheng-Chun; Lee, Tzu-Kuei; Kuo, Yan-Fu

    2015-01-01

    The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D) images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D) images by using microcomputed tomography (μCT) and to examine the floral shape variations by using geometric morphometrics (GM). To demonstrate the advantages of the 3D-μCT-GM approach, we applied the approach to a second-generation population of florist's gloxinia (Sinningia speciosa) crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks) from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-μCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations. PMID:26442038

  18. Quantifying floral shape variation in 3D using microcomputed tomography: a case study of a hybrid line between actinomorphic and zygomorphic flowers.

    PubMed

    Wang, Chun-Neng; Hsu, Hao-Chun; Wang, Cheng-Chun; Lee, Tzu-Kuei; Kuo, Yan-Fu

    2015-01-01

    The quantification of floral shape variations is difficult because flower structures are both diverse and complex. Traditionally, floral shape variations are quantified using the qualitative and linear measurements of two-dimensional (2D) images. The 2D images cannot adequately describe flower structures, and thus lead to unsatisfactory discrimination of the flower shape. This study aimed to acquire three-dimensional (3D) images by using microcomputed tomography (μCT) and to examine the floral shape variations by using geometric morphometrics (GM). To demonstrate the advantages of the 3D-μCT-GM approach, we applied the approach to a second-generation population of florist's gloxinia (Sinningia speciosa) crossed from parents of zygomorphic and actinomorphic flowers. The flowers in the population considerably vary in size and shape, thereby served as good materials to test the applicability of the proposed phenotyping approach. Procedures were developed to acquire 3D volumetric flower images using a μCT scanner, to segment the flower regions from the background, and to select homologous characteristic points (i.e., landmarks) from the flower images for the subsequent GM analysis. The procedures identified 95 landmarks for each flower and thus improved the capability of describing and illustrating the flower shapes, compared with typically lower number of landmarks in 2D analyses. The GM analysis demonstrated that flower opening and dorsoventral symmetry were the principal shape variations of the flowers. The degrees of flower opening and corolla asymmetry were then subsequently quantified directly from the 3D flower images. The 3D-μCT-GM approach revealed shape variations that could not be identified using typical 2D approaches and accurately quantified the flower traits that presented a challenge in 2D images. The approach opens new avenues to investigate floral shape variations.

  19. Study of the Microfocus X-Ray Tube Based on a Point-Like Target Used for Micro-Computed Tomography

    PubMed Central

    Zhou, Rifeng; Zhou, Xiaojian; Li, Xiaobin; Cai, Yufang; Liu, Fenglin

    2016-01-01

    For a micro-Computed Tomography (Micro-CT) system, the microfocus X-ray tube is an essential component because the spatial resolution of CT images, in theory, is mainly determined by the size and stability of the X-ray focal spot of the microfocus X-ray tube. However, many factors, including voltage fluctuations, mechanical vibrations, and temperature changes, can cause the size and the stability of the X-ray focal spot to degrade. A new microfocus X-ray tube based on a point-like micro-target in which the X-ray target is irradiated with an unfocused electron beam was investigated. EGS4 Monte Carlo simulation code was employed for the calculation of the X-ray intensity produced from the point-like micro-target and the substrate. The effects of several arrangements of the target material, target and beam size were studied. The simulation results demonstrated that if the intensity of X-rays generated at the point-like target is greater than half of the X-ray intensity produced on the substrate, the X-ray focal spot is determined in part by the point-like target rather than by the electron beam in the conventional X-ray tube. In theory, since it is able to reduce those unfavorable effects such as the electron beam trajectory swinging and the beam size changing for the microfocus X-ray tube, it could alleviate CT image artifacts caused by the X-ray focal spot shift and size change. PMID:27249559

  20. Use of micro-computed tomography to evaluate the effects of exercise on preventing the degeneration of articular cartilage in tail-suspended rats

    NASA Astrophysics Data System (ADS)

    Luan, Hui-Qin; Sun, Lian-Wen; Huang, Yun-Fei; Wu, Xin-tong; Niu, Haijun; Liu, Hong; Fan, Yu-Bo

    2015-07-01

    Space flight has been shown to induce bone loss and muscle atrophy, which could initiate the degeneration of articular cartilage. Countermeasures to prevent bone loss and muscle atrophy have been explored, but few spaceflight or ground-based studies have focused on the effects on cartilage degeneration. In this study, we investigated the effects of exercise on articular cartilage deterioration in tail-suspended rats. Thirty-two female Sprague-Dawley rats were randomly divided into four groups (n = 8 in each): tail suspension (TS), tail suspension plus passive motion (TSP), tail suspension plus active exercise (TSA), and control (CON) groups. In the TS, TSP, and TSA groups, the rat hindlimbs were unloaded for 21 days by tail suspension. Next, the cartilage thickness and volume, and the attenuation coefficient of the distal femur were evaluated by micro-computed tomography (μCT). Histological analysis was used to assess the surface integrity of the cartilage, cartilage thickness, and chondrocytes. The results showed that: (1) the cartilage thickness on the distal femur was significantly lower in the TS and TSP groups compared with the CON and TSA groups; (2) the cartilage volume in the TS group was significantly lower compared with the CON, TSA, and TSP groups; and (3) histomorphology showed that the chondrocytes formed clusters where the degree of matrix staining was lower in the TS and TSP groups. There were no significant differences between any of these parameters in the CON and TSA groups. The cartilage thickness measurements obtained by μCT and histomorphology correlated well. In general, tail suspension could induce articular cartilage degeneration, but active exercise was effective in preventing this degeneration in tail-suspended rats.

  1. Noninvasive Monitoring and Evaluation of the Renal Structure and Function in a Mouse Model of Unilateral Ureteral Occlusion Using Microcomputed Tomography.

    PubMed

    Hou, Jiangang; Fujino, Masayuki; Cai, Songjie; Ding, Qiang; Li, Xiao-Kang

    2015-07-01

    Mouse unilateral ureteral occlusion (UUO) is widely used as a model of renal experimental obstructive nephropathy with interstitial fibrosis. Microcomputed tomography (micro-CT) imaging has the potential to produce quantitative images. The aim of this study was to establish standard images of micro-CT for renal anatomic and functional evaluations in a mouse model of UUO. UUO was induced in adult male mice BALB/c. In total, 27 mice were used in this study. Three mice per group (a total of 6 groups) were examined with contrast-enhanced micro-CT prior to UUO (day 0) and on days 1, 3, 5, 7, 10, and 14 after UUO. In order to determine the histopathologic correlations at each point in time, contrast-enhanced micro-CT imaging was performed in the 18 remaining mice. All animals were sacrificed, and both kidneys were harvested after the final micro-CT examination. UUO resulted in hydronephrosis and changes in the renal parenchyma. The predominant alteration was substantial changes in the hemodynamics of the renal vascular system after ureteral obstruction for 24 hours or longer, which may be resulting from increased action of vasoconstrictors versus vasodilators. The renal parenchyma was significantly reduced after 1 week, and the features of the histologic changes supported the findings of the micro-CT images. In the contralateral unobstructed kidneys, the images showed a normal structure and function and the pathohistology revealed a normal histoarchitecture. Micro-CT is a useful tool for providing noninvasive monitoring and evaluating the renal structure and function.

  2. Quantifying Not Only Bone Loss, but Also Soft Tissue Swelling, in a Murine Inflammatory Arthritis Model Using Micro-Computed Tomography

    PubMed Central

    Perilli, E; Cantley, M; Marino, V; Crotti, T N; Smith, M D; Haynes, D R; Dharmapatni, A A S S K

    2015-01-01

    In rodent models of inflammatory arthritis, bone erosion has been non-invasively assessed by micro-computed tomography (micro-CT). However, non-invasive assessments of paw swelling (oedema) are still based on clinical grading by visual evaluation, or measurements by callipers, not always reliable for the tiny mouse paws. The aim of this work was to demonstrate a novel straightforward 3D micro-CT analysis protocol capable of quantifying not only joint bone erosion, but also soft tissue swelling, from the same scans, in a rodent inflammatory arthritis model. Balb/c mice were divided into two groups: collagen antibody-induced arthritis (CAIA) and CAIA treated with prednisolone, the latter reflecting an established treatment in human rheumatoid arthritis. Clinical paw scores were recorded. On day 10, front paws were assessed by micro-CT and histology. Micro-CT measurements included paw volume (bone and soft tissue together) and bone volume at the radiocarpal joint, and bone volume from the radiocarpal to the metacarpophalangeal joint. Micro-CT analysis revealed significantly lower paw volume (−36%, P < 0.01) and higher bone volume (+17%, P < 0.05) in prednisolone-treated CAIA mice compared with untreated CAIA mice. Paw volume and bone volume assessed by micro-CT correlated significantly with clinical and histological scores (|r| > 0.5, P < 0.01). Untreated CAIA mice showed significantly higher clinical scores, higher inflammation levels histologically, cartilage and bone degradation, and pannus formation, compared with treated mice (P < 0.01). The presented novel micro-CT analysis protocol enables 3D-quantification of paw swelling at the micrometre level, along with the typically assessed bone erosion, using the same images/scans, without altering the scanning procedure or using contrast agents. PMID:25424522

  3. Study of the Microfocus X-Ray Tube Based on a Point-Like Target Used for Micro-Computed Tomography.

    PubMed

    Zhou, Rifeng; Zhou, Xiaojian; Li, Xiaobin; Cai, Yufang; Liu, Fenglin

    2016-01-01

    For a micro-Computed Tomography (Micro-CT) system, the microfocus X-ray tube is an essential component because the spatial resolution of CT images, in theory, is mainly determined by the size and stability of the X-ray focal spot of the microfocus X-ray tube. However, many factors, including voltage fluctuations, mechanical vibrations, and temperature changes, can cause the size and the stability of the X-ray focal spot to degrade. A new microfocus X-ray tube based on a point-like micro-target in which the X-ray target is irradiated with an unfocused electron beam was investigated. EGS4 Monte Carlo simulation code was employed for the calculation of the X-ray intensity produced from the point-like micro-target and the substrate. The effects of several arrangements of the target material, target and beam size were studied. The simulation results demonstrated that if the intensity of X-rays generated at the point-like target is greater than half of the X-ray intensity produced on the substrate, the X-ray focal spot is determined in part by the point-like target rather than by the electron beam in the conventional X-ray tube. In theory, since it is able to reduce those unfavorable effects such as the electron beam trajectory swinging and the beam size changing for the microfocus X-ray tube, it could alleviate CT image artifacts caused by the X-ray focal spot shift and size change.

  4. Longitudinal Use of Micro-computed Tomography Does Not Alter Microarchitecture of the Proximal Tibia in Sham or Ovariectomized Sprague-Dawley Rats.

    PubMed

    Longo, Amanda B; Sacco, Sandra M; Salmon, Phil L; Ward, Wendy E

    2016-06-01

    In vivo micro-computed tomography (μCT) provides the ability to measure longitudinal changes to tibia microarchitecture, but the effect of this radiation is not well understood. The right proximal tibia of Sprague-Dawley rats (n = 12/group) randomized to Sham-control (Sham) or ovariectomy (OVX) surgery at 12 weeks of age was scanned using μCT at 13, 17, 21, and 25 weeks of age, at a resolution of 18 μm and a radiation dose of 603 mGy. The left proximal tibia was scanned only at 25 weeks of age to serve as an internal non-irradiated control. Repeated irradiation did not affect tibia microarchitecture in Sham or OVX groups, although there was an increase in cortical eccentricity (P < 0.05). All trabecular outcomes and cortical BMD were different (P < 0.05) between groups after only 1 week post-surgery and differences persisted to study endpoint. Characteristic changes to trabecular bone were observed in OVX rats over time. Interactions of time and hormone status were found for cortical BMD (P < 0.001), Ps. Pm., and Ec. Pm. (P < 0.05). Repeated irradiation of the tibia at 13, 17, 21, and 25 weeks does not cause adverse effects to microarchitecture, regardless of hormone status. This radiation dose can be applied over a typical 3-month study period to comprehensively understand how an intervention alters tibia microarchitecture without confounding effects of radiation.

  5. Effect of acid etching on marginal adaptation of mineral trioxide aggregate to apical dentin: microcomputed tomography and scanning electron microscopy analysis.

    PubMed

    Al-Fouzan, Khalid; Al-Garawi, Ziad; Al-Hezaimi, Khalid; Javed, Fawad; Al-Shalan, Thakib; Rotstein, Ilan

    2012-12-01

    The present investigation assessed the effect of acid etching on marginal adaptation of white- and gray-colored mineral trioxide aggregate (MTA) to apical dentin using microcomputed tomography (micro-CT) and scanning electron microscopy (SEM). Sixty-four extracted single-rooted human maxillary teeth were used. Following root-end resection and apical preparation, the teeth were equally divided into four groups according to the following root end filling materials: (i) white-colored MTA (WMTA), (ii) etched WMTA (EWMTA), (iii) gray-colored MTA (GMTA) and (iv) etched GMTA (EGMTA). After 48 h, the interface between root-end filling materials and the dentinal walls was assessed using micro-CT and SEM. Data were statistically analyzed using the Kruskal-Wallis and Dunn tests. Micro-CT analysis revealed gap volumes between the apical cavity dentin walls and EGMTA, GMTA, EWMTA and WMTA of (0.007 1±0.004) mm(3), (0.053±0.002) mm(3), (0.003 6±0.001) mm(3) and (0.005 9±0.002) mm(3) respectively. SEM analysis revealed gap sizes for EGMTA, WMTA, EWMTA and GMTA to be (492.3±13.8) µm, (594.5±17.12) µm, (543.1±15.33) µm and (910.7±26.2) µm respectively. A significant difference in gap size between root end preparations filled with GMTA and EGMTA was found (P<0.05). No significance difference in gap size between WMTA and EWMTA were found in either SEM or micro-CT analysis. In conclusion, pre-etching of apical dentin can provide a better seal for GMTA but not for WMTA.

  6. Integrated 3D view of postmating responses by the Drosophila melanogaster female reproductive tract, obtained by micro-computed tomography scanning.

    PubMed

    Mattei, Alexandra L; Riccio, Mark L; Avila, Frank W; Wolfner, Mariana F

    2015-07-07

    Physiological changes in females during and after mating are triggered by seminal fluid components in conjunction with female-derived molecules. In insects, these changes include increased egg production, storage of sperm, and changes in muscle contraction within the reproductive tract (RT). Such postmating changes have been studied in dissected RT tissues, but understanding their coordination in vivo requires a holistic view of the tissues and their interrelationships. Here, we used high-resolution, multiscale micro-computed tomography (CT) scans to visualize and measure postmating changes in situ in the Drosophila female RT before, during, and after mating. These studies reveal previously unidentified dynamic changes in the conformation of the female RT that occur after mating. Our results also reveal how the reproductive organs temporally shift in concert within the confines of the abdomen. For example, we observed chiral loops in the uterus and in the upper common oviduct that relax and constrict throughout sperm storage and egg movement. We found that specific seminal fluid proteins or female secretions mediate some of the postmating changes in morphology. The morphological movements, in turn, can cause further changes due to the connections among organs. In addition, we observed apparent copulatory damage to the female intima, suggesting a mechanism for entry of seminal proteins, or other exogenous components, into the female's circulatory system. The 3D reconstructions provided by high-resolution micro-CT scans reveal how male and female molecules and anatomy interface to carry out and coordinate mating-dependent changes in the female's reproductive physiology.

  7. Iodine potassium iodide improves the contrast-to-noise ratio of micro-computed tomography images of the human middle ear.

    PubMed

    Rohani, S A; Ghomashchi, S; Umoh, J; Holdsworth, D W; Agrawal, S K; Ladak, H M

    2016-12-01

    High-resolution imaging of middle-ear geometry is necessary for finite-element modeling. Although micro-computed tomography (microCT) is widely used because of its ability to image bony structures of the middle ear, it is difficult to visualize soft tissues - including the tympanic membrane and the suspensory ligaments/tendons - because of lack of contrast. The objective of this research is to quantitatively evaluate the efficacy of iodine potassium iodide (IKI) solution as a contrast agent. Six human temporal bones were used in this experiment, which were obtained in right-left pairs, from three cadaveric heads. All bones were fixed using formaldehyde. Three bones (one from each pair) were stained in IKI solution for 2 days, whereas the other three were not stained. Samples were scanned using a microCT system at a resolution of 20 μm. Eight soft tissues in the middle ear were segmented: anterior mallear ligament, incudomallear joint, lateral mallear ligament, posterior incudal ligament, stapedial annular ligament, stapedius muscle, tympanic membrane and tensor tympani muscle. Contrast-to-noise ratios (CNRs) of each soft tissue were calculated for each temporal bone. Combined CNRs of the soft tissues in unstained samples were 6.1 ± 3.0, whereas they were 8.1 ± 2.7 in stained samples. Results from Welch's t-test indicate significant difference between the two groups at a 95% confidence interval. Results for paired t-tests for each of the individual soft tissues also indicated significant improvement of contrast in all tissues after staining. Relatively large soft tissues in the middle ear such as the tympanic membrane and the tensor tympani muscle were impacted by staining more than smaller tissues such as the stapedial annular ligament. The increase in contrast with IKI solution confirms its potential application in automatic segmentation of the middle-ear soft tissues.

  8. Three-dimensional analysis of the pulp cavity on surface models of molar teeth, using X-ray micro-computed tomography.

    PubMed

    Markvart, Merete; Bjørndal, Lars; Darvann, Tron A; Larsen, Per; Dalstra, Michel; Kreiborg, Sven

    2012-03-01

    The purpose of this study was to investigate the scanning and segmentation precision of surface models of molars for the detection of small volumes, such as the reduced pulp cavity; formation of mineral deposits; detection of narrow root canals and to improve the clinical and morphological understanding of the number of root canals and their configuration. Eighteen human molars were scanned using X-ray micro-computed tomography. The reconstruction of the surface models had a precision of <1 voxel, using three-dimensional software and quantitative color mapping. In order to relate the measurements to changes over time the size of the pulp chambers was classified in two well-defined groups. The mineral deposits were more evenly distributed in small pulp chambers than in large, but complete root canal calcification was never observed. No difference was observed in the material with respect to the presence of intra-radicular connections. In upper molars, a second mesiobuccal canal (mb(2)) frequency of 91% was found. The difference in length between the first mesiobuccal canal (mb(1)) and mb(2) was <1 mm. The number of root canals could be related to the number of root cones. In summary, three-dimensional surface models were made with a high precision; an increased accumulation of mineral deposits was noted in molars with small pulp chambers and combined with the consistent pattern of intra-radicular connections, the potential endodontic treatment complexity is underlined in such cases. Finally, an improved understanding of root canal prevalence was reached, when merging well-defined definitions on root morphology and clinical classification systems.

  9. Sine systemate chaos? A versatile tool for earthworm taxonomy: non-destructive imaging of freshly fixed and museum specimens using micro-computed tomography.

    PubMed

    Fernández, Rosa; Kvist, Sebastian; Lenihan, Jennifer; Giribet, Gonzalo; Ziegler, Alexander

    2014-01-01

    In spite of the high relevance of lumbricid earthworms ('Oligochaeta': Lumbricidae) for soil structure and functioning, the taxonomy of this group of terrestrial invertebrates remains in a quasi-chaotic state. Earthworm taxonomy traditionally relies on the interpretation of external and internal morphological characters, but the acquisition of these data is often hampered by tedious dissections or restricted access to valuable and rare museum specimens. The present state of affairs, in conjunction with the difficulty of establishing primary homologies for multiple morphological features, has led to an almost unrivaled instability in the taxonomy and systematics of certain earthworm groups, including Lumbricidae. As a potential remedy, we apply for the first time a non-destructive imaging technique to lumbricids and explore the future application of this approach to earthworm taxonomy. High-resolution micro-computed tomography (μCT) scanning of freshly fixed and museum specimens was carried out using two cosmopolitan species, Aporrectodea caliginosa and A. trapezoides. By combining two-dimensional and three-dimensional dataset visualization techniques, we demonstrate that the morphological features commonly used in earthworm taxonomy can now be analyzed without the need for dissection, whether freshly fixed or museum specimens collected more than 60 years ago are studied. Our analyses show that μCT in combination with soft tissue staining can be successfully applied to lumbricid earthworms. An extension of the approach to other families is poised to strengthen earthworm taxonomy by providing a versatile tool to resolve the taxonomic chaos currently present in this ecologically important, but taxonomically neglected group of terrestrial invertebrates.

  10. A pilot study evaluating shaved cavity margins with micro-computed tomography: a novel method for predicting lumpectomy margin status intraoperatively.

    PubMed

    Tang, Rong; Coopey, Suzanne B; Buckley, Julliette M; Aftreth, Owen P; Fernandez, Leopoldo J; Brachtel, Elena F; Michaelson, James S; Gadd, Michele A; Specht, Michelle C; Koerner, Frederick C; Smith, Barbara L

    2013-01-01

    Microscopically clear lumpectomy margins are essential in breast conservation, as involved margins increase local recurrence. Currently, 18-50% of lumpectomies have close or positive margins that require re-excision. We assessed the ability of micro-computed tomography (micro-CT) to evaluate lumpectomy shaved cavity margins (SCM) intraoperatively to determine if this technology could rapidly identify margin involvement by tumor and reduce re-excision rates. Twenty-five SCM from six lumpectomies were evaluated with a Skyscan 1173 table top micro-CT scanner (Skyscan, Belgium). Micro-CT results were compared to histopathological results. We scanned three SCM at once with a 7-minute scanning protocol, and studied a total of 25 SCM from six lumpectomies. Images of the SCM were evaluated for radiographic signs of breast cancer including clustered microcalcifications and spiculated masses. SCM were negative by micro-CT in 19/25 (76%) and negative (≥2 mm) by histopathology in 19/25 (76%). Margin status by micro-CT was concordant with histopathology in 23/25 (92%). Micro-CT overestimated margin involvement in 1/25 and underestimated margin involvement in 1/25. Micro-CT had an 83.3% positive predictive value, a 94.7% negative predictive value, 83.3% sensitivity, and 94.7% specificity for evaluation of SCM. Evaluation of SCM by micro-CT is an accurate and promising method of intraoperative margin assessment in breast cancer patients. The scanning time required is short enough to permit real-time feedback to the operating surgeon, allowing immediate directed re-excision.

  11. A technique for evaluating bone ingrowth into 3D printed, porous Ti6Al4V implants accurately using X-ray micro-computed tomography and histomorphometry.

    PubMed

    Palmquist, Anders; Shah, Furqan A; Emanuelsson, Lena; Omar, Omar; Suska, Felicia

    2017-03-01

    This paper investigates the application of X-ray micro-computed tomography (micro-CT) to accurately evaluate bone formation within 3D printed, porous Ti6Al4V implants manufactured using Electron Beam Melting (EBM), retrieved after six months of healing in sheep femur and tibia. All samples were scanned twice (i.e., before and after resin embedding), using fast, low-resolution scans (Skyscan 1172; Bruker micro-CT, Kontich, Belgium), and were analysed by 2D and 3D morphometry. The main questions posed were: (i) Can low resolution, fast scans provide morphometric data of bone formed inside (and around) metal implants with a complex, open-pore architecture?, (ii) Can micro-CT be used to accurately quantify both the bone area (BA) and bone-implant contact (BIC)?, (iii) What degree of error is introduced in the quantitative data by varying the threshold values?, and (iv) Does resin embedding influence the accuracy of the analysis? To validate the accuracy of micro-CT measurements, each data set was correlated with a corresponding centrally cut histological section. The results show that quantitative histomorphometry corresponds strongly with 3D measurements made by micro-CT, where a high correlation exists between the two techniques for bone area/volume measurements around and inside the porous network. On the contrary, the direct bone-implant contact is challenging to estimate accurately or reproducibly. Large errors may be introduced in micro-CT measurements when segmentation is performed without calibrating the data set against a corresponding histological section. Generally, the bone area measurement is strongly influenced by the lower threshold limit, while the upper threshold limit has little or no effect. Resin embedding does not compromise the accuracy of micro-CT measurements, although there is a change in the contrast distributions and optimisation of the threshold ranges is required.

  12. Integrated 3D view of postmating responses by the Drosophila melanogaster female reproductive tract, obtained by micro-computed tomography scanning

    PubMed Central

    Mattei, Alexandra L.; Riccio, Mark L.; Avila, Frank W.; Wolfner, Mariana F.

    2015-01-01

    Physiological changes in females during and after mating are triggered by seminal fluid components in conjunction with female-derived molecules. In insects, these changes include increased egg production, storage of sperm, and changes in muscle contraction within the reproductive tract (RT). Such postmating changes have been studied in dissected RT tissues, but understanding their coordination in vivo requires a holistic view of the tissues and their interrelationships. Here, we used high-resolution, multiscale micro-computed tomography (CT) scans to visualize and measure postmating changes in situ in the Drosophila female RT before, during, and after mating. These studies reveal previously unidentified dynamic changes in the conformation of the female RT that occur after mating. Our results also reveal how the reproductive organs temporally shift in concert within the confines of the abdomen. For example, we observed chiral loops in the uterus and in the upper common oviduct that relax and constrict throughout sperm storage and egg movement. We found that specific seminal fluid proteins or female secretions mediate some of the postmating changes in morphology. The morphological movements, in turn, can cause further changes due to the connections among organs. In addition, we observed apparent copulatory damage to the female intima, suggesting a mechanism for entry of seminal proteins, or other exogenous components, into the female’s circulatory system. The 3D reconstructions provided by high-resolution micro-CT scans reveal how male and female molecules and anatomy interface to carry out and coordinate mating-dependent changes in the female’s reproductive physiology. PMID:26041806

  13. Contrast-enhanced micro-computed tomography using ExiTron nano6000 for assessment of liver injury

    PubMed Central

    Hua, Xiang-Wei; Lu, Tian-Fei; Li, Da-Wei; Wang, Wei-Gang; Li, Jun; Liu, Zhen-Ze; Lin, Wei-Wei; Zhang, Jian-Jun; Xia, Qiang

    2015-01-01

    AIM: To explore the potential of contrast-enhanced computed tomography (CECT) using ExiTron nano6000 for assessment of liver lesions in mouse models. METHODS: Three mouse models of liver lesions were used: bile duct ligation (BDL), lipopolysaccharide (LPS)/D-galactosamine (D-GalN), and alcohol. After injection with the contrast agent ExiTron nano6000, the mice were scanned with micro-CT. Liver lesions were evaluated using CECT images, hematoxylin and eosin staining, and serum aminotransferase levels. Macrophage distribution in the injury models was shown by immunohistochemical staining of CD68. The in vitro studies measured the densities of RAW264.7 under different conditions by CECT. RESULTS: In the in vitro studies, CECT provided specific and strong contrast enhancement of liver in mice. CECT could present heterogeneous images and densities of injured livers induced by BDL, LPS/D-GalN, and alcohol. The liver histology and immunochemistry of CD68 demonstrated that both dilated biliary tracts and necrosis in the injured livers could lead to the heterogeneous distribution of macrophages. The in vitro study showed that the RAW264.7 cell masses had higher densities after LPS activation. CONCLUSION: Micro-CT with the contrast agent ExiTron nano6000 is feasible for detecting various liver lesions by emphasizing the heterogeneous textures and densities of CECT images. PMID:26185375

  14. Reproducibility of Global and Local Reconstruction of Three-Dimensional Micro-Computed Tomography of Iliac Crest Biopsies

    SciTech Connect

    Jorgensen,S.; Eaker, D.; Vercnocke, A.; Ritman, E.

    2008-01-01

    Variation in computed tomography (CT) image grayscale and spatial geometry due to specimen orientation, magnification, voxel size, differences in X-ray photon energy and limited field-of-view during the scan, were evaluated in repeated micro-CT scans of iliac crest biopsies and test phantoms. Using the micro-CT scanner on beamline X2B at the Brookhaven National Laboratory's National Synchrotron Light Source, 3-D micro-CT images were generated. They consisted of up to 1024 X 24002, 4-mum cubic voxels, each with 16-bit gray-scale. We also reconstructed the images at 16-, 32-, and 48-mum voxel resolution. Scan data were reconstructed from the complete profiles using filtered back-projection and from truncated profiles using profile-extension and with a Local reconstruction algorithm. Three biopsies and one bonelike test phantom were each rescanned at three different times at annual intervals. For the full-data-set reconstructions, the reproducibility of the estimates of mineral content of bone at mean bone opacity value, was {+-}28.8 mg/cm3, i.e., 2.56%, in a 4-mum cubic voxel at the 95% confidence level. The reproducibility decreased with increased voxel size. The interscan difference in imaged bone volume ranged from 0.86 {+-} 0.64% at 4-mum voxel resolution, and 2.64 {+-} 2.48% at 48 mum.

  15. Micro-computed tomography derived anisotropy detects tumor provoked deviations in bone in an orthotopic osteosarcoma murine model.

    PubMed

    Cole, Heather A; Ohba, Tetsuro; Ichikawa, Jiro; Nyman, Jeffry S; Cates, Justin M M; Haro, Hirotaka; Schwartz, Herbert S; Schoenecker, Jonathan G

    2014-01-01

    Radiographic imaging plays a crucial role in the diagnosis of osteosarcoma. Currently, computed-tomography (CT) is used to measure tumor-induced osteolysis as a marker for tumor growth by monitoring the bone fractional volume. As most tumors primarily induce osteolysis, lower bone fractional volume has been found to correlate with tumor aggressiveness. However, osteosarcoma is an exception as it induces osteolysis and produces mineralized osteoid simultaneously. Given that competent bone is highly anisotropic (systematic variance in its architectural order renders its physical properties dependent on direction of load) and that tumor induced osteolysis and osteogenesis are structurally disorganized relative to competent bone, we hypothesized that μCT-derived measures of anisotropy could be used to qualitatively and quantitatively detect osteosarcoma provoked deviations in bone, both osteolysis and osteogenesis, in vivo. We tested this hypothesis in a murine model of osteosarcoma cells orthotopically injected into the tibia. We demonstrate that, in addition to bone fractional volume, μCT-derived measure of anisotropy is a complete and accurate method to monitor osteosarcoma-induced osteolysis. Additionally, we found that unlike bone fractional volume, anisotropy could also detect tumor-induced osteogenesis. These findings suggest that monitoring tumor-induced changes in the structural property isotropy of the invaded bone may represent a novel means of diagnosing primary and metastatic bone tumors.

  16. Multi-scale, micro-computed tomography-based pore network models to simulate drainage in heterogeneous rocks

    NASA Astrophysics Data System (ADS)

    Bultreys, Tom; Van Hoorebeke, Luc; Cnudde, Veerle

    2015-04-01

    The multi-phase flow behavior of complex rocks with broad pore size distributions often digresses from classical relations. Pore-scale simulation methods can be a great tool to improve the understanding of this behavior. However, the broad range of pore sizes present makes it difficult to gather the experimental input data needed for these simulations and poses great computational challenges. We developed a novel micro-computed-tomography (micro-CT) based dual pore network model (DPNM), which takes microporosity into account in an upscaled fashion using symbolic network elements called micro-links, while treating the macroporosity as a traditional pore network model. The connectivity and conductivity of the microporosity is derived from local information measured on micro-CT scans. Microporous connectivity is allowed both in parallel and in series to the macropore network. We allow macropores to be drained as a consequence of their connection with microporosity, permitting simulations where the macropore network alone does not percolate. The validity of the method is shown by treating an artificial network and a network extracted from a micro-CT scan of Estaillades limestone.

  17. Evaluation of urinary stones ex vivo with micro-computed tomography: preliminary results of an investigational technique.

    PubMed

    Huri, Emre; Tatar, Ilkan; Germiyanoglu, Cankon; Karakan, Tolga; Celik, Hakan Hamdi; Ersoy, Orkun

    2011-01-01

    To evaluate the ultrastructural features of the urinary stones removed with endoscopic stone surgery, using micro computed tomography (micro-CT). Patients who had endoscopic surgery for renal or ureteral stones removal were included in this study. After surgery, the stones were classified into three groups and investigated with Skyscan 1174 micro-CT. Group I underwent percutaneous nephrolithotomy (PNL) with ultrasonic lithotripsy; group II had ureteroscopic stone surgery (USS) with pneumatic lithotripsy; and group III (the control group) had stone removal with USS or PNL without lithotripsy. Stone homogeneity, voids, and the internal structure of the stones were evaluated. Chi-square test was used to evaluate the difference statistically. P values less than .05 were considered statistically significant. A total of 24 "calcium oxalate monohydrate" stones from 24 patients were scanned with micro-CT. Stones treated with ultrasonic lithotripsy (group I) were more fragile, fragmented, and cracked than those treated with the pneumatic lithotripsy (group II; P = .01). Stones in group II were more homogeneous and smooth than those in group I and resembled those of the control group (P = .02). Homogeneous, non-fragile stones and heterogeneous, fragile calculi were seen in all groups. The stone fragility could be confirmed by micro-CT investigation. Ultrasonic lithotripters increase the stone fragility, which is demonstrated with increased heterogeneity by micro-CT.

  18. Biomedical implications of dental-ceramic defects investigated by numerical simulation, radiographic, microcomputer tomography, and time-domain optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Sinescu, Cosmin; Negrutiu, Meda Lavinia; Ionita, Ciprian; Marsavina, Liviu; Negru, Radu; Topala, Florin; Petrescu, Emanuela; Rominu, Roxana; Fabriky, Mihai; Bradu, Adrian; Rominu, Mihai; Podoleanu, Adrian Gh.

    2011-10-01

    Imagistic investigation of the metal-ceramic crowns and fixed partial prostheses represent a very important issue in nowadays dentistry. At this time, in dental office, it is difficult or even impossible to evaluate a metal ceramic crown or bridge before setting it in the oral cavity. The possibilities of ceramic fractures are due to small fracture lines or material defects inside the esthetic layers. Material and methods: In this study 25 metal ceramic crowns and fixed partial prostheses were investigated by radiographic method (Rx), micro computer tomography (MicroCT) and optical coherence tomography (OCT) working in Time Domain, at 1300 nm. The OCT system contains two interferometers and one scanner. For each incident analysis a stuck made of 100 slices was obtain. These slices were used in order to obtain a 3D model of the ceramic interface. After detecting the presence and the positions of the ceramic defects the numerical simulation method was used to estimate the biomechanical effect of the masticatory forces on fractures propagations in ceramic materials. Results: For all the dental ceramic defects numerical simulation analysis was performed. The simulation of crack propagation shows that the crack could initiate from the upper, lower or both parts of the defect and propagates through the ceramic material where tensile stress field is present. RX and MicroCT are very powerful instruments that provide a good characterization of the dental construct. It is important to observe the reflections due to the metal infrastructure that could affect the evaluation of the metal ceramic crowns and bridges. The OCT investigations could complete the imagistic evaluation of the dental construct by offering important information when it is need it.

  19. Quantification of Osseointegration of Plasma-Polymer Coated Titanium Alloyed Implants by means of Microcomputed Tomography versus Histomorphometry

    PubMed Central

    Gabler, Carolin; Zietz, Carmen; Bieck, Richard; Göhler, Rebecca; Lindner, Tobias; Haenle, Maximilian; Meichsner, Jürgen; Testrich, Holger; Nowottnick, Mathias; Frerich, Bernhard

    2015-01-01

    A common method to derive both qualitative and quantitative data to evaluate osseointegration of implants is histomorphometry. The present study describes a new image reconstruction algorithm comparing the results of bone-to-implant contact (BIC) evaluated by means of µCT with histomorphometry data. Custom-made conical titanium alloyed (Ti6Al4V) implants were inserted in the distal tibial bone of female Sprague-Dawley rats. Different surface configurations were examined: Ti6Al4V implants with plasma-polymerized allylamine (PPAAm) coating and plasma-polymerized ethylenediamine (PPEDA) coating as well as implants without surface coating. After six weeks postoperatively, tibiae were explanted and BIC was determined by µCT (3D) and afterwards by histomorphometry (2D). In comparison to uncoated Ti6Al4V implants demonstrating low BIC of 32.4% (histomorphometry) and 51.3% (µCT), PPAAm and PPEDA coated implants showed a nonsignificant increase in BIC (histomorphometry: 45.7% and 53.5% and µCT: 51.8% and 62.0%, resp.). Mean BIC calculated by µCT was higher for all surface configurations compared to BIC detected by histomorphometry. Overall, a high correlation coefficient of 0.70 (p < 0.002) was found between 3D and 2D quantification of BIC. The μCT analysis seems to be suitable as a nondestructive and accurate 3D imaging method for the evaluation of the bone-implant interface. PMID:26064874

  20. Investigation of a pre-clinical mandibular bone notch defect model in miniature pigs: clinical computed tomography, micro-computed tomography, and histological evaluation

    PubMed Central

    2016-01-01

    Objectives To validate a critical-size mandibular bone defect model in miniature pigs. Materials and Methods Bilateral notch defects were produced in the mandible of dentally mature miniature pigs. The right mandibular defect remained untreated while the left defect received an autograft. Bone healing was evaluated by computed tomography (CT) at 4 and 16 weeks, and by micro-CT and non-decalcified histology at 16 weeks. Results In both the untreated and autograft treated groups, mineralized tissue volume was reduced significantly at 4 weeks post-surgery, but was comparable to the pre-surgery levels after 16 weeks. After 16 weeks, CT analysis indicated that significantly greater bone was regenerated in the autograft treated defect than in the untreated defect (P=0.013). Regardless of the treatment, the cortical bone was superior to the defect remodeled over 16 weeks to compensate for the notch defect. Conclusion The presence of considerable bone healing in both treated and untreated groups suggests that this model is inadequate as a critical-size defect. Despite healing and adaptation, the original bone geometry and quality of the pre-injured mandible was not obtained. On the other hand, this model is justified for evaluating accelerated healing and mitigating the bone remodeling response, which are both important considerations for dental implant restorations. PMID:26904491

  1. Rescuing Perishable Neuroanatomical Information from a Threatened Biodiversity Hotspot: Remote Field Methods for Brain Tissue Preservation Validated by Cytoarchitectonic Analysis, Immunohistochemistry, and X-Ray Microcomputed Tomography.

    PubMed

    Hughes, Daniel F; Walker, Ellen M; Gignac, Paul M; Martinez, Anais; Negishi, Kenichiro; Lieb, Carl S; Greenbaum, Eli; Khan, Arshad M

    2016-01-01

    Biodiversity hotspots, which harbor more endemic species than elsewhere on Earth, are increasingly threatened. There is a need to accelerate collection efforts in these regions before threatened or endangered species become extinct. The diverse geographical, ecological, genetic, morphological, and behavioral data generated from the on-site collection of an individual specimen are useful for many scientific purposes. However, traditional methods for specimen preparation in the field do not permit researchers to retrieve neuroanatomical data, disregarding potentially useful data for increasing our understanding of brain diversity. These data have helped clarify brain evolution, deciphered relationships between structure and function, and revealed constraints and selective pressures that provide context about the evolution of complex behavior. Here, we report our field-testing of two commonly used laboratory-based techniques for brain preservation while on a collecting expedition in the Congo Basin and Albertine Rift, two poorly known regions associated with the Eastern Afromontane biodiversity hotspot. First, we found that transcardial perfusion fixation and long-term brain storage, conducted in remote field conditions with no access to cold storage laboratory equipment, had no observable impact on cytoarchitectural features of lizard brain tissue when compared to lizard brain tissue processed under laboratory conditions. Second, field-perfused brain tissue subjected to prolonged post-fixation remained readily compatible with subsequent immunohistochemical detection of neural antigens, with immunostaining that was comparable to that of laboratory-perfused brain tissue. Third, immersion-fixation of lizard brains, prepared under identical environmental conditions, was readily compatible with subsequent iodine-enhanced X-ray microcomputed tomography, which facilitated the non-destructive imaging of the intact brain within its skull. In summary, we have validated

  2. Long-term Risedronate Treatment Normalizes Mineralization and Continues to Preserve Trabecular Architecture: Sequential Triple Biopsy Studies with Micro-Computed Tomography

    SciTech Connect

    Borah,B.; Dufresne, T.; Ritman, E.; Jorgensen, S.; Liu, S.; Chmielewski, P.; Phipps, R.; Zhou, X.; Sibonga, J.; Turner, R.

    2006-01-01

    The objective of the study was to assess the time course of changes in bone mineralization and architecture using sequential triple biopsies from women with postmenopausal osteoporosis (PMO) who received long-term treatment with risedronate. Transiliac biopsies were obtained from the same subjects (n = 7) at baseline and after 3 and 5 years of treatment with 5 mg daily risedronate. Mineralization was measured using 3-dimensional (3D) micro-computed tomography (CT) with synchrotron radiation and was compared to levels in healthy premenopausal women (n = 12). Compared to the untreated PMO women at baseline, the premenopausal women had higher average mineralization (Avg-MIN) and peak mineralization (Peak-MIN) by 5.8% (P = 0.003) and 8.0% (P = 0.003), respectively, and lower ratio of low to high-mineralized bone volume (BMR-V) and surface area (BMR-S) by 73.3% (P = 0.005) and 61.7% (P = 0.003), respectively. Relative to baseline, 3 years of risedronate treatment significantly increased Avg-MIN (4.9 {+-} 1.1%, P = 0.016) and Peak-MIN (6.2 {+-} 1.5%, P = 0.016), and significantly decreased BMR-V (-68.4 {+-} 7.3%, P = 0.016) and BMR-S (-50.2 {+-} 5.7%, P = 0.016) in the PMO women. The changes were maintained at the same level when treatment was continued up to 5 years. These results are consistent with the significant reduction of turnover observed after 3 years of treatment and which was similarly maintained through 5 years of treatment. Risedronate restored the degree of mineralization and the ratios of low- to high-mineralized bone to premenopausal levels after 3 years of treatment, suggesting that treatment reduced bone turnover in PMO women to healthy premenopausal levels. Conventional micro-CT analysis further demonstrated that bone volume (BV/TV) and trabecular architecture did not change from baseline up to 5 years of treatment, suggesting that risedronate provided long-term preservation of trabecular architecture in the PMO women. Overall, risedronate provided

  3. Influence of longitudinal radiation exposure from microcomputed tomography scanning on skeletal muscle function and metabolic activity in female CD-1 mice.

    PubMed

    Mikhaeil, John S; Sacco, Sandra M; Saint, Caitlin; Gittings, William; Bunda, Jordan; Giles, Cameron R; Andrew Fajardo, Val; Vandenboom, Rene; Ward, Wendy E; LeBlanc, Paul J

    2017-07-01

    Microcomputed tomography (μCT) is an imaging technology to assess bone microarchitecture, a determinant of bone strength. When measured in vivo, μCT exposes the skeletal site of interest to a dose of radiation, in addition to nearby skeletal muscles as well. Therefore, the aim of this study was to determine the effects of repeated radiation exposure from in vivo μCT on muscle health - specifically, muscle morphometrics, contractile function, and enzyme activity. This study exposed the right hind limb of female mice to either a low (26 cGy) or moderate (46 cGy) dose, at 2, 4, and 6 months of age, while the left hind limb of the same animal was exposed to a single dose at 6 months to serve as a nonirradiated control. Muscle weight, cross-sectional area, isometric contractile function, and representative maximal enzyme activities of amino acid, fatty acid, glucose, and oxidative metabolism in extensor digitorum longus (EDL) and soleus were assessed. Low-dose radiation had no effect. In contrast, moderate-dose radiation resulted in a 5% increase in time-to-peak tension and 16% increase in half-relaxation time of isometric twitches in EDL, although these changes were not seen when normalized to force. Moderate-dose radiation also resulted in an ~33% decrease in citrate synthase activity in soleus but not EDL, with no changes to the other enzymes measured. Thus, three low doses of radiation over 6 months had no effect on contractile function or metabolic enzyme activity in soleus and EDL of female mice. In contrast, three moderate doses of radiation over 6 months induced some effects on metabolic enzyme activity in soleus but not EDL Future studies that wish to investigate muscle tissue that is adjacent to scanned bone should take radiation exposure dose into consideration. © 2017 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  4. Reproducibility of bone micro-architecture measurements in rodents by in vivo micro-computed tomography is maximized with three-dimensional image registration.

    PubMed

    Nishiyama, Kyle K; Campbell, Graeme M; Klinck, Robert J; Boyd, Steven K

    2010-01-01

    In vivo micro-computed tomography (microCT) is a new method to monitor longitudinal changes of bone micro-architecture. Common animal models of bone diseases are mice and rats, and it is important to know the reproducibility of the bone measurements in order to correctly interpret results. When performing baseline and follow-up acquisitions, variation in the scan region will influence the parameters, and it has yet to be investigated if three-dimensional (3D) registration can improve the reproducibility. Two typical breeds of mice and one typical breed of rats were scanned four times each using microCT and standard bone morphological and density measurements were calculated. Image registration was used to find the overlapping regions between the scans within each series of animal data and only overlapping regions were analyzed for the bone parameters. Reproducibility was determined for each animal both pre- and post-registration. For the rats, results included a bone volume ratio (BV/TV) precision error of 5.46%, cortical thickness (Ct.Th) error of 1.97%, and tissue mineral density (TMD) of 2.00%. For the BL6 mice, precision errors were 3.00% (BV/TV), 0.95% (Ct.Th), and 0.94% (TMD), and for the C3H mice 2.68% (BV/TV), 1.52% (Ct.Th), and 1.72% (TMD). After image registration there was a significant improvement in reproducibility in most parameters for the rats. In general, metric parameters such as bone volume ratio had better reproducibility than the non-metric parameters connectivity density and structure model index. With 3D registration, reproducibility improved the results obtained by the experienced operators in this study. Registration may serve to equalize reproducibility of operators with different skill levels and across laboratories. It also improves efficiency by reducing the amount of hand-contouring required. This reproducibility data will be important for the interpretation of current and future longitudinal microCT studies.

  5. Rescuing Perishable Neuroanatomical Information from a Threatened Biodiversity Hotspot: Remote Field Methods for Brain Tissue Preservation Validated by Cytoarchitectonic Analysis, Immunohistochemistry, and X-Ray Microcomputed Tomography

    PubMed Central

    Hughes, Daniel F.; Walker, Ellen M.; Gignac, Paul M.; Martinez, Anais; Negishi, Kenichiro; Lieb, Carl S.; Greenbaum, Eli

    2016-01-01

    Biodiversity hotspots, which harbor more endemic species than elsewhere on Earth, are increasingly threatened. There is a need to accelerate collection efforts in these regions before threatened or endangered species become extinct. The diverse geographical, ecological, genetic, morphological, and behavioral data generated from the on-site collection of an individual specimen are useful for many scientific purposes. However, traditional methods for specimen preparation in the field do not permit researchers to retrieve neuroanatomical data, disregarding potentially useful data for increasing our understanding of brain diversity. These data have helped clarify brain evolution, deciphered relationships between structure and function, and revealed constraints and selective pressures that provide context about the evolution of complex behavior. Here, we report our field-testing of two commonly used laboratory-based techniques for brain preservation while on a collecting expedition in the Congo Basin and Albertine Rift, two poorly known regions associated with the Eastern Afromontane biodiversity hotspot. First, we found that transcardial perfusion fixation and long-term brain storage, conducted in remote field conditions with no access to cold storage laboratory equipment, had no observable impact on cytoarchitectural features of lizard brain tissue when compared to lizard brain tissue processed under laboratory conditions. Second, field-perfused brain tissue subjected to prolonged post-fixation remained readily compatible with subsequent immunohistochemical detection of neural antigens, with immunostaining that was comparable to that of laboratory-perfused brain tissue. Third, immersion-fixation of lizard brains, prepared under identical environmental conditions, was readily compatible with subsequent iodine-enhanced X-ray microcomputed tomography, which facilitated the non-destructive imaging of the intact brain within its skull. In summary, we have validated

  6. Micro-computed tomography analysis of post space preparation in root canals filled with carrier-based thermoplasticized gutta-percha.

    PubMed

    Schroeder, A A; Ford, N L; Coil, J M

    2017-03-01

    To determine whether post space preparation deviated from the root canal preparation in canals filled with Thermafil, GuttaCore or warm vertically compacted gutta-percha. Forty-two extracted human permanent maxillary lateral incisors were decoronated, and their root canals instrumented using a standardized protocol. Samples were divided into three groups and filled with Thermafil (Dentsply Tulsa Dental Specialties, Johnson City, TN, USA), GuttaCore (Dentsply Tulsa Dental Specialties) or warm vertically compacted gutta-percha, before post space preparation was performed with a GT Post drill (Dentsply Tulsa Dental Specialties). Teeth were scanned using micro-computed tomography after root filling and again after post space preparation. Scans were examined for number of samples with post space deviation, linear deviation of post space preparation and minimum root thickness before and after post space preparation. Parametric data were analysed with one-way analysis of variance (anova) or one-tailed paired Student's t-tests, whilst nonparametric data were analysed with Fisher's exact test. Deviation occurred in eight of forty-two teeth (19%), seven of fourteen from the Thermafil group (50%), one of fourteen from the GuttaCore group (7%), and none from the gutta-percha group. Deviation occurred significantly more often in the Thermafil group than in each of the other two groups (P < 0.05). Linear deviation of post space preparation was greater in the Thermafil group than in both of the other groups and was significantly greater than that of the gutta-percha group (P < 0.05). Minimum root thickness before post space preparation was significantly greater than it was after post space preparation for all groups (P < 0.01). The differences between the Thermafil, GuttaCore and gutta-percha groups in the number of samples with post space deviation and in linear deviation of post space preparation were associated with the presence or absence of a carrier as well as the

  7. Efficacy of ProTaper NEXT Compared with Reciproc in Removing Obturation Material from Severely Curved Root Canals: A Micro-Computed Tomography Study.

    PubMed

    Nevares, Giselle; de Albuquerque, Diana S; Freire, Laila G; Romeiro, Kaline; Fogel, Howard M; Dos Santos, Marcelo; Cunha, Rodrigo S

    2016-05-01

    The aim of this study was to compare the remaining root canal obturation, volume of dentin removed, and apical transportation after retreatment of severely curved root canals by using Reciproc (REC) or ProTaper NEXT (PTN) systems. Twenty-eight mesial canals of mandibular molars were instrumented and then obturated with gutta-percha and sealer and allocated into 2 balanced groups (n = 14), the REC group (R25 file) and the PTN group (X3 and X2 files). Micro-computed tomography analysis was performed to assess the percentage of residual obturation material, the amount of dentin removed, and apical transportation. The effective time for the removal of obturation and procedural errors were recorded. Obturation was effectively removed from the root canal in the REC and PTN groups (P ≤ .001), and the percentages of remaining obturation material were similar between both groups (84.8% PTN vs 86.5% REC) (P > .05). The amount of dentin removed (3.17 ± 2.64 mm(3) PTN versus 3.50 ± 2.82 mm(3) REC), apical transportation (at 1 mm: 0.096 ± 0.189 mm PTN versus 0.093 ± 0.186 mm REC; at 3 mm: 0.059 ± 0.069 mm PTN versus 0.082 ± 0.080 mm REC; at 5 mm: 0.097 ± 0.093 mm PTN versus 0.133 ± 0.138 mm REC), and the working time (269.69 ± 19.25 seconds PTN versus 268.62 ± 16.37 seconds REC) were also similar in both groups (P > .05). One file fractured in the REC group. Both systems were equally effective in the removal of obturation from severely curved canals and can be used for retreatment. Neither system could completely remove the obturation material; therefore, additional techniques are needed to improve cleaning of the root canal. Copyright © 2016 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  8. Three-Dimensional Quantification of Calcium Salt-Composite Resorption (CSC) In Vitro by Micro-computed Tomography (Micro-CT)

    NASA Astrophysics Data System (ADS)

    Winkler, T.; Dai, X. Y.; Mielke, G.; Vogt, S.; Buechner, H.; Schantz, J. T.; Harder, Y.; Machens, H. G.; Morlock, M. M.; Schilling, A. F.

    2014-04-01

    The commonly applied cell-based, two-dimensional (2D) in vitro resorption assays for biomaterials are limited in a variety of cases, including high initial roughness of material surface, uncontrollable solubilization (or resorption) of the entire material surface, or complex three-dimensional (3D) structure of the bioactive material itself. All these make the accurate assessment and successful selection of the optimal bone substitute material difficult. In vivo, micro-computed tomography (micro-CT) has been widely applied for the analysis of bone physiology and pathology, as well as for the 3D analysis of scaffolds for bone tissue engineering. In this study, we show that micro-CT can also be applied for the in vitro analysis of osteoclast-mediated resorption of biomaterials. For our experiments, we chose a calcium salt-composite (composite of calcium sulphate (CSC), calcium carbonate, glycerin-1,2,3-tripalmiate), which evades common 2D in vitro resorption analysis as a result of its high surface roughness and material composition. Human osteoclasts were differentiated from precursor cells on the surface of the material for 28 days. Cells were analyzed for expression of tartrate-resistant acid phosphatase 5b (TRAP5b), multinuclearity, and size. Volumetric analysis of resorption was performed by micro-CT. Multinucleated osteoclasts developed on the surface of the material. TRAP5b expression of the cells on CSC was comparable with TRAP5b expression of cells cultivated on dentin for the first 3 weeks of culture. At day 28, TRAP5b expression, cell number, and size of the TRAP+ cells were reduced on the CSC when compared with cells on dentin. Volumetric anaylsis by micro-CT showed a strong cellular effect on resorption of CSC. We consider micro-CT to be a promising technique for 3D quantification of cell-based resorption that will allow the study of cellular resorption of materials in vitro, which were up to now confined to animal experimental analysis.

  9. A micro-computed tomography assessment of the efficacy of rotary and reciprocating techniques for filling material removal in root canal retreatment.

    PubMed

    Monguilhott Crozeta, Bruno; Damião de Sousa-Neto, Manoel; Bianchi Leoni, Graziela; Francisco Mazzi-Chaves, Jardel; Terezinha Corrêa Silva-Sousa, Yara; Baratto-Filho, Flares

    2016-11-01

    The aim of this study was to compare the efficacy of rotary and reciprocating techniques for removing filling material from root canals, using micro-computed tomography (micro-CT) imaging. The distal root canals of 42 human mandibular molars were instrumented with hand files up to size 40 according to a step-down technique and obturated with gutta-percha and an epoxy resin-based sealer using Tagger's hybrid technique. Teeth were divided into six groups (n = 7) according to the instruments used for removal of filling material: group PTUR (Protaper Universal Retreatment), group W40 (WaveOne 40.08), group R40 (Reciproc 40.06), group R50 (Reciproc 50.05), group W25/W40 (WaveOne 25.08/40.08), and group R25/R40/R50 (Reciproc 25.08/40.06/50.05). Teeth were scanned with a micro-CT device before and after use of the instruments to calculate the percentage of remaining filling material. Data were compared using one-way ANOVA and Fisher's LSD test at 5 % significance level. The mean percentage of remaining filling material was significantly lower when canals were retreated with the set of instruments R25/R40/R50 and single instruments W40 and R50 compared with the set of instruments W25/W40 (P < 0.05), which promoted material compaction in the apical region. None of the retreatment techniques removed the root fillings completely. PTUR instruments performed equally effective regarding filling removal compared with W40, R40, R50, W25/W40, and R25/R40/R50. For WaveOne, the use of a single instrument (size 40, taper 0.08) was more effective in removing filling material, while for Reciproc showed similar cleaning ability using single instrument or combination of instruments. The results of this in vitro study provide consistent information on filling material removal capacity of mechanized systems during retreatment at the different root canal thirds.

  10. Quantifying the impact of soil compaction on root system architecture in tomato (Solanum lycopersicum) by X-ray micro-computed tomography

    PubMed Central

    Tracy, Saoirse R.; Black, Colin R.; Roberts, Jeremy A.; Sturrock, Craig; Mairhofer, Stefan; Craigon, Jim; Mooney, Sacha J.

    2012-01-01

    Background and Aims We sought to explore the interactions between roots and soil without disturbance and in four dimensions (i.e. 3-D plus time) using X-ray micro-computed tomography. Methods The roots of tomato Solanum lycopersicum ‘Ailsa Craig’ plants were visualized in undisturbed soil columns for 10 consecutive days to measure the effect of soil compaction on selected root traits including elongation rate. Treatments included bulk density (1·2 vs. 1·6 g cm−3) and soil type (loamy sand vs. clay loam). Key Results Plants grown at the higher soil bulk density exploited smaller soil volumes (P < 0·05) and exhibited reductions in root surface area (P < 0·001), total root volume (P < 0·001) and total root length (P < 0·05), but had a greater mean root diameter (P < 0·05) than at low soil bulk density. Swelling of the root tip area was observed in compacted soil (P < 0·05) and the tortuosity of the root path was also greater (P < 0·01). Root elongation rates varied greatly during the 10-d observation period (P < 0·001), increasing to a maximum at day 2 before decreasing to a minimum at day 4. The emergence of lateral roots occurred later in plants grown in compacted soil (P < 0·01). Novel rooting characteristics (convex hull volume, centroid and maximum width), measured by image analysis, were successfully employed to discriminate treatment effects. The root systems of plants grown in compacted soil had smaller convex hull volumes (P < 0·05), a higher centre of mass (P < 0·05) and a smaller maximum width than roots grown in uncompacted soil. Conclusions Soil compaction adversely affects root system architecture, influencing resource capture by limiting the volume of soil explored. Lateral roots formed later in plants grown in compacted soil and total root length and surface area were reduced. Root diameter was increased and swelling of the root tip occurred in compacted soil. PMID:22362666

  11. Elucidation of the internal physical and chemical microstructure of pharmaceutical granules using X-ray micro-computed tomography, Raman microscopy and infrared spectroscopy.

    PubMed

    Crean, Barry; Parker, Andrew; Roux, Delphine Le; Perkins, Mark; Luk, Shen Y; Banks, Simon R; Melia, Colin D; Roberts, Clive J

    2010-11-01

    X-ray micro-computed tomography (XMCT) was used in conjunction with confocal Raman mapping to measure the intra-granular pore size, binder volumes and to provide spatial and chemical maps of internal granular components in α-lactose monohydrate granules formulated with different molecular weights of polyvinyl pyrrolidone (PVP). Infrared spectroscopy was used to understand the molecular association of binder domains. Granules were prepared by high-shear aqueous granulation from α-lactose monohydrate and PVP K29/32 or K90. XMCT was used to visualise the granule microstructure, intra-granular binder distribution and measure intra-granular porosity, which was subsequently related to intrusion porosimetry measurements. Confocal Raman microscopy and infrared microscopy were employed to investigate the distribution of components within the granule and explore the nature of binder substrate interactions. XMCT data sets of internal granule microstructure provided values of residual porosity in the lactose:PVP K29/32 and lactose:PVP K90 granules of 32.41 ± 4.60% and 22.40 ± 0.03%, respectively. The binder volumes of the lactose:PVP K29/32 and lactose:PVP K90 granules were 2.98 ± 0.10% and 3.38 ± 0.07%, respectively, and were attributed to PVP-rich binder domains within the granule. Confocal Raman microscopy revealed anisotropic domains of PVP between 2 μm and 20 μm in size surrounded by larger particles of lactose, in both granule types. Raman data showed that PVP domains contained various amounts of lactose, whilst IR microscopy determined that the PVP was molecularly associated with lactose, rather than residual water. The work shows that XMCT can be applied to investigate granular microstructure and resolve the porosity and the excipient and binder volumes. Combining this technique with vibrational techniques provides further structural information and aids the interpretations of the XMCT images. When used complementarily, these techniques highlighted that

  12. A Comparison of Students' Approaches to Inquiry, Conceptual Learning, and Attitudes in Simulation-Based and Microcomputer-Based Laboratories

    ERIC Educational Resources Information Center

    Chen, Sufen; Chang, Wen-Hua; Lai, Chih-Hung; Tsai, Cheng-Yue

    2014-01-01

    The purpose of this project was to investigate the effects of virtual versus physical manipulation using a simulation-based laboratory activity (SBL) and a microcomputer-based laboratory activity (MBL). Both the SBL and the MBL used computers to collect, graph, and analyze data. A major difference was that the MBL allowed the students to…

  13. A Comparison of Students' Approaches to Inquiry, Conceptual Learning, and Attitudes in Simulation-Based and Microcomputer-Based Laboratories

    ERIC Educational Resources Information Center

    Chen, Sufen; Chang, Wen-Hua; Lai, Chih-Hung; Tsai, Cheng-Yue

    2014-01-01

    The purpose of this project was to investigate the effects of virtual versus physical manipulation using a simulation-based laboratory activity (SBL) and a microcomputer-based laboratory activity (MBL). Both the SBL and the MBL used computers to collect, graph, and analyze data. A major difference was that the MBL allowed the students to…

  14. Comparison of Deconvolution Filters for Photoacoustic Tomography

    PubMed Central

    Van de Sompel, Dominique; Sasportas, Laura S.; Jokerst, Jesse V.; Gambhir, Sanjiv S.

    2016-01-01

    In this work, we compare the merits of three temporal data deconvolution methods for use in the filtered backprojection algorithm for photoacoustic tomography (PAT). We evaluate the standard Fourier division technique, the Wiener deconvolution filter, and a Tikhonov L-2 norm regularized matrix inversion method. Our experiments were carried out on subjects of various appearances, namely a pencil lead, two man-made phantoms, an in vivo subcutaneous mouse tumor model, and a perfused and excised mouse brain. All subjects were scanned using an imaging system with a rotatable hemispherical bowl, into which 128 ultrasound transducer elements were embedded in a spiral pattern. We characterized the frequency response of each deconvolution method, compared the final image quality achieved by each deconvolution technique, and evaluated each method’s robustness to noise. The frequency response was quantified by measuring the accuracy with which each filter recovered the ideal flat frequency spectrum of an experimentally measured impulse response. Image quality under the various scenarios was quantified by computing noise versus resolution curves for a point source phantom, as well as the full width at half maximum (FWHM) and contrast-to-noise ratio (CNR) of selected image features such as dots and linear structures in additional imaging subjects. It was found that the Tikhonov filter yielded the most accurate balance of lower and higher frequency content (as measured by comparing the spectra of deconvolved impulse response signals to the ideal flat frequency spectrum), achieved a competitive image resolution and contrast-to-noise ratio, and yielded the greatest robustness to noise. While the Wiener filter achieved a similar image resolution, it tended to underrepresent the lower frequency content of the deconvolved signals, and hence of the reconstructed images after backprojection. In addition, its robustness to noise was poorer than that of the Tikhonov filter. The

  15. Dual-energy X-ray absorptiometry, peripheral quantitative computed tomography, and micro-computed tomography techniques are discordant for bone density and geometry measurements in the guinea pig.

    PubMed

    Mak, Ivy L; DeGuire, Jason R; Lavery, Paula; Agellon, Sherry; Weiler, Hope A

    2016-05-01

    This study aims to examine agreement among bone mineral content (BMC) and density (BMD) estimates obtained using dual-energy X-ray absorptiometry (DXA), peripheral quantitative computed tomography (pQCT), and micro-computed tomography (μCT) against high-resolution μCT and bone ash of the guinea pig femur. Middle-aged (n = 40, 86 weeks) male guinea pigs underwent in vivo followed by ex vivo DXA (Hologic QDR 4500A) scanning for intact and excised femur BMC and areal density. To assess bone architecture and strength, excised femurs were scanned on pQCT (Stratec XCT 2000L) as well as on two μCT scanners (LaTheta LCT-200; Skyscan 1174), followed by three-point bending test. Reproducibility was determined using triplicate scans; and agreement assessed using Bland-Altman plots with reference methods being high-resolution μCT (Skyscan) for BMD and bone ashing for BMC. All techniques showed satisfactory ex vivo precision (CV 0.05-4.3 %). However, bias compared to the reference method was highest (207.5 %) in trabecular bone volume fraction (BV/TV) measured by LaTheta, and unacceptable in most total femur and cortical bone measurements. Volumetric BMD (vBMD) and BV/TV derived by LaTheta and pQCT at the distal metaphysis were biased from the Skyscan by an average of 49.3 and 207.5 %, respectively. Variability of vBMD, BV/TV and cross-sectional area at the diaphysis ranged from -5.5 to 30.8 %. LaTheta best quantified total femur BMC with an upper bias of 3.3 %. The observed differences among imaging techniques can be attributable to inherent dissimilarity in construction design, calibration, segmentation and scanning resolution used. These bone imaging tools are precise but are not comparable, at least when assessing guinea pig bones.

  16. Microcomputers in Marketing Education.

    ERIC Educational Resources Information Center

    Heath, Betty

    Microcomputers are becoming increasingly available in education, especially in secondary education. It is estimated that in 1980, 50 percent of secondary schools had at least one microcomputer or computer terminal available. Within 3 years, there may be 400,000 microcomputers in secondary schools and 50,000 secondary teachers with computing as…

  17. Microcomputers in Geography.

    ERIC Educational Resources Information Center

    Snaden, James N.; And Others

    Geographers in the United States rely heavily on microcomputers. They employ microcomputers to enhance three general categories of tasks: word processing and other productivity needs, geographic instruction, and discipline-specific applications. Word processing and desktop publishing continue to be the primary uses of microcomputers by…

  18. Basic Information on Microcomputers.

    ERIC Educational Resources Information Center

    Dembowski, Frederick L.

    1983-01-01

    The second in a series of articles on the use of microcomputers in the school business office contains a summary of the most important concepts and issues concerning the central processing unit and internal storage aspects of the microcomputer. All microcomputer jargon is italicized for easy recognition. (MLF)

  19. Microcomputers in Geography.

    ERIC Educational Resources Information Center

    Snaden, James N.; And Others

    Geographers in the United States rely heavily on microcomputers. They employ microcomputers to enhance three general categories of tasks: word processing and other productivity needs, geographic instruction, and discipline-specific applications. Word processing and desktop publishing continue to be the primary uses of microcomputers by…

  20. Comparison of ultrasound tomography methods in circular geometry

    NASA Astrophysics Data System (ADS)

    Leach, Richard, Jr.; Azevedo, Steve G.; Berryman, James G.; Bertete-Aguirre, Hugo; Chambers, David H.; Mast, Jeffrey E.; Littrup, Peter J.; Duric, Nebojsa; Johnson, Steven A.; Wuebbeling, Frank

    2002-04-01

    Extremely high quality data was acquired using an experimental ultrasound scanner developed at Lawrence Livermore National Laboratory using a 2D ring geometry with up to 720 transmitter/receiver transducer positions. This unique geometry allows reflection and transmission modes and transmission imaging and quantification of a 3D volume using 2D slice data. Standard image reconstruction methods were applied to the data including straight-ray filtered back projection, reflection tomography, and diffraction tomography. Newer approaches were also tested such as full wave, full wave adjoint method, bent-ray filtered backprojection, and full-aperture tomography. A variety of data sets were collected including a formalin-fixed human breast tissue sample, a commercial ultrasound complex breast phantom, and cylindrical objects with and without inclusions. The resulting reconstruction quality of the images ranges from poor to excellent. The method and results of this study are described including like-data reconstructions produced by different algorithms with side-by-side image comparisons. Comparisons to medical B-scan and x-ray CT scan images are also shown. Reconstruction methods with respect to image quality using resolution, noise, and quantitative accuracy, and computational efficiency metrics will also be discussed.

  1. A Comparison of Ultrasound Tomography Methods in Circular Geometry

    SciTech Connect

    Leach, R R; Azevedo, S G; Berryman, J G; Bertete-Aquirre, H R; Chambers, D H; Mast, J E; Littrup, P; Duric, N; Johnson, S A; Wuebbeling, F

    2002-01-24

    Extremely high quality data was acquired using an experimental ultrasound scanner developed at Lawrence Livermore National Laboratory using a 2D ring geometry with up to 720 transmitter/receiver transducer positions. This unique geometry allows reflection and transmission modes and transmission imaging and quantification of a 3D volume using 2D slice data. Standard image reconstruction methods were applied to the data including straight-ray filtered back projection, reflection tomography, and diffraction tomography. Newer approaches were also tested such as full wave, full wave adjoint method, bent-ray filtered back projection, and full-aperture tomography. A variety of data sets were collected including a formalin-fixed human breast tissue sample, a commercial ultrasound complex breast phantom, and cylindrical objects with and without inclusions. The resulting reconstruction quality of the images ranges from poor to excellent. The method and results of this study are described including like-data reconstructions produced by different algorithms with side-by-side image comparisons. Comparisons to medical B-scan and x-ray CT scan images are also shown. Reconstruction methods with respect to image quality using resolution, noise, and quantitative accuracy, and computational efficiency metrics will also be discussed.

  2. Comparison of the predictions of one- and two-compartment microcomputer programs for long-term tobramycin therapy.

    PubMed

    Hatton, R C; Massey, K L; Russell, W L

    1984-01-01

    A retrospective study of patients receiving tobramycin compared the accuracy of predictions of actual trough serum concentrations using two commercially available microcomputer software programs. Twelve patients met the study criteria of intravenous tobramycin treatment for more than 10 days with serum concentration monitoring within the first 5 days and after 10 days of therapy. No patients received dialysis. Twenty-five serum concentrations were compared. Predictions within 0.2 microgram/ml were considered clinically "exact." No significant differences were found by chi-square analysis for any of the four possible choices (p less than 0.3). One of the programs, distributed by Dista Pharmaceuticals, offers a one-compartment model, a two-compartment model, and a two-compartment prenephrotoxic option. SIMKIN, a program marketed by Medical Engineering, Inc., uses a two-compartment model. Overall, the predictions errors were small, but occasionally were clinically significant. Further evaluation of microcomputer programs for therapeutic drug monitoring is necessary to document their impact on predicting drug efficacy and toxicity.

  3. Root Canal Morphology and Configuration of 179 Maxillary First Molars by Means of Micro-computed Tomography: An Ex Vivo Study.

    PubMed

    Briseño-Marroquín, Benjamín; Paqué, Frank; Maier, Karolin; Willershausen, Brita; Wolf, Thomas Gerhard

    2015-12-01

    The objective of this study was to propose a root canal configuration description method and to investigate the root canal system morphology of the maxillary first molar by means of micro-computed tomographic imaging. The root canal configuration, foramina, and accessory canal frequency of 179 maxillary first molars were investigated by means of micro-computed tomographic imaging and 3-dimensional software imaging. The root canal configuration and main foramina number are described from coronal to apical with a 4-digit system. The most frequent root canal configurations were 1-1-1/1 (45.8%), 2-2-2/2 (25.1%) and 2-2-1/1 (10.1%) in mesiobuccal roots and 1-1-1/1 in distobuccal (97.2%) and palatal (98.9%) roots. The first mesiobuccal (MB1) root canal had 1 accessory canal in 26.3% of the teeth, the distobuccal root canal had 12.3%, and the palatal root canal had 9.5%; in the second mesiobuccal root canal, there was rarely 1 accessory canal. There was 1 accessory canal in 26.3%, 12.3%, and 9.5% in the MB1, distobuccal, and palatal root canals, respectively. The MB1, distobuccal, and palatal root canals had 1 main foramen. The MB2 had 1 main foramen in 39.0% of the teeth and no main foramen in 61.0%. The root canal configuration of maxillary first molars is quite diversified. Contrary to our expectations in this research, the mesiobuccal root has predominantly 1 root canal entrance and only 1 main foramen. Anatomic variations including connecting and accessory canals occur in any third of root. Copyright © 2015 American Association of Endodontists. All rights reserved.

  4. Administrative Uses of Microcomputers.

    ERIC Educational Resources Information Center

    Crawford, Chase

    1987-01-01

    This paper examines the administrative uses of the microcomputer, stating that high performance educational managers are likely to have microcomputers in their organizations. Four situations that would justify the use of a computer are: (1) when massive amounts of data are processed through well-defined operations; (2) when data processing is…

  5. Administrative Uses of Microcomputers.

    ERIC Educational Resources Information Center

    Crawford, Chase

    1987-01-01

    This paper examines the administrative uses of the microcomputer, stating that high performance educational managers are likely to have microcomputers in their organizations. Four situations that would justify the use of a computer are: (1) when massive amounts of data are processed through well-defined operations; (2) when data processing is…

  6. Doing Physics with Microcomputers.

    ERIC Educational Resources Information Center

    Bak, Per

    1983-01-01

    Describes how microcomputers can perform very demanding/large-scale physics calculations at speeds not much slower than those of modern, full-size computers. Among the examples provided are a Monte Carlo simulation of the three-dimensional Ising model and a program (for the Apple microcomputer) using the time-independent Schrodinger Equation. (JN)

  7. Microcomputers in Special Education.

    ERIC Educational Resources Information Center

    Education Turnkey Systems, Inc., Falls Church, VA.

    One of four reports designed to assess the current state of new technologies, the document reviews the status of microcomputers in regular and special education now and for the next five years. Briefly discussed are components, software, and prices of microcomputers. Next addressed are general educational usage for instructional and administrative…

  8. The Microcomputer Revolution.

    ERIC Educational Resources Information Center

    Kinne, Harold C.

    The history of the development of the microcomputer industry since its inception in 1975 is explored in this brief paper, which pays special attention to the advent of the small business computer. The author describes the growth of sales, the development of successful companies, the early resistance to use of microcomputers in business, and the…

  9. Doing Physics with Microcomputers.

    ERIC Educational Resources Information Center

    Bak, Per

    1983-01-01

    Describes how microcomputers can perform very demanding/large-scale physics calculations at speeds not much slower than those of modern, full-size computers. Among the examples provided are a Monte Carlo simulation of the three-dimensional Ising model and a program (for the Apple microcomputer) using the time-independent Schrodinger Equation. (JN)

  10. Microcomputer Troubleshooting Training.

    ERIC Educational Resources Information Center

    Heiserman, Russell L.

    The microcomputer troubleshooter is regarded as a technically knowledgeable member of the team and is more active in equipment selection, site preparation, site supervision and preventive maintenance, and on-site training of operators, maintenance people, and programmers. Microcomputer troubleshooting can be incorporated into an electronics…

  11. Problem Solving Using Microcomputers.

    ERIC Educational Resources Information Center

    Demana, Franklin; Waits, Bert

    1987-01-01

    It is argued that microcomputer technology has evolved to the stage that it should be routinely used by mathematics students at all levels. It is shown how the use of microcomputers can change the way problems are solved. Computer-generated graphics are highlighted. (PK)

  12. Microcomputer Software Collections.

    ERIC Educational Resources Information Center

    Demas, Samuel

    1985-01-01

    Presents overview of special considerations in developing microcomputer software collections, review of standardized cataloging practices, and discussion of problems of selection and acquisition of software. Policies governing loan procedures for microcomputer software which involve four types of copy protection (patent, trade secret, contract,…

  13. Microcomputers "Goto" School.

    ERIC Educational Resources Information Center

    Piele, Donald T.

    This paper is a report of a pilot project in which a microcomputer was placed in a sixth grade classroom for eight weeks for the purpose of developing logical thinking skills. Students were first given instruction on how to program the APPLE II microcomputer to draw color graphics designs; they were then given similar problems to solve using the…

  14. The Microcomputer Revolution.

    ERIC Educational Resources Information Center

    Kinne, Harold C.

    The history of the development of the microcomputer industry since its inception in 1975 is explored in this brief paper, which pays special attention to the advent of the small business computer. The author describes the growth of sales, the development of successful companies, the early resistance to use of microcomputers in business, and the…

  15. Circulation Systems on Microcomputers.

    ERIC Educational Resources Information Center

    Carlson, Gary

    1984-01-01

    Reports on the use of microcomputers in comprehensive library circulation systems. Topics covered include system requirements (reliability, completeness); determining circulation system needs (saving money, improving service, modernization); limitations of microcomputers (capacity, kinds of data stored, number of stations or terminals); system…

  16. Communications Software for Microcomputers.

    ERIC Educational Resources Information Center

    Bruman, Janet L.

    Focusing on the use of microcomputers as "smart terminals" for accessing time-sharing systems for libraries, this document discusses the communications software needed to allow the microcomputer to appear as a terminal to the remote host. The functions which communications software programs are designed to perform are defined and…

  17. Microcomputers in Higher Education.

    ERIC Educational Resources Information Center

    McLean, Robert S., Ed.; McLean, Ruth W., Ed.

    1981-01-01

    Some of the areas in which Ontario educators currently employ microcomputers in higher education are addressed in several articles, bibliographies, and book reviews. Various uses of computer-managed instruction and computer-assisted instruction (CAI) at Humber College of Applied Arts and Technology are outlined by Frank A. Ford. Microcomputer CAI…

  18. Comparison of optical coherence tomography imaging of cataracts with histopathology

    NASA Astrophysics Data System (ADS)

    DiCarlo, Cheryl D.; Roach, William P.; Gagliano, Donald A.; Boppart, Stephen A.; Hammer, Daniel X.; Cox, Ann B.; Fujimoto, James G.

    1999-10-01

    This paper presents a comparison of in vivo optical coherence tomography (OCT) captured cataract images to subsequent histopathological examination of the lenticular opacities. OCT imaging was performed on anesthetized Rhesus monkeys, known as the delayed effects colony (DEC), with documented cataracts. These monkeys were exposed to several types of radiation during the mid and late 1960s. The radiation and age related cataracts in these animals were closely monitored using a unique grading system developed specifically for the DEC. In addition to this system, a modified version of a common cataract grading scheme for use in humans was applied. Of the original 18 monkeys imaged, lenses were collected at necropsy from seven of these animals, processed, and compared to OCT images. Results showed a direct correlation between the vertical OCT images and the cataractous lesions seen on corresponding histopathological sections of the lenses. Based on the images obtained and their corresponding documented comparison to histopathology, OCT showed tremendous potential to aid identification and characterization of cataracts. There can be artifactual problems with the images related to movement and shadows produced by opacities. However, with the advent of increased speed in imaging and multiplanar imaging, these disadvantages may easily be overcome.

  19. Microcomputer Applications in Analytical Chemistry.

    ERIC Educational Resources Information Center

    Long, Joseph W.

    The first part of this paper addresses the following topics: (1) the usefulness of microcomputers; (2) applications for microcomputers in analytical chemistry; (3) costs; (4) major microcomputer systems and subsystems; and (5) which microcomputer to buy. Following these brief comments, the major focus of the paper is devoted to a discussion of…

  20. Microcomputer Applications in Analytical Chemistry.

    ERIC Educational Resources Information Center

    Long, Joseph W.

    The first part of this paper addresses the following topics: (1) the usefulness of microcomputers; (2) applications for microcomputers in analytical chemistry; (3) costs; (4) major microcomputer systems and subsystems; and (5) which microcomputer to buy. Following these brief comments, the major focus of the paper is devoted to a discussion of…

  1. Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison.

    PubMed

    Oltra, Enrique; Cox, Timothy C; LaCourse, Matthew R; Johnson, James D; Paranjpe, Avina

    2017-02-01

    Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis. Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency. There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group. The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform.

  2. Retreatability of two endodontic sealers, EndoSequence BC Sealer and AH Plus: a micro-computed tomographic comparison

    PubMed Central

    Oltra, Enrique; Cox, Timothy C.; LaCourse, Matthew R.; Johnson, James D.

    2017-01-01

    Objectives Recently, bioceramic sealers like EndoSequence BC Sealer (BC Sealer) have been introduced and are being used in endodontic practice. However, this sealer has limited research related to its retreatability. Hence, the aim of this study was to evaluate the retreatability of two sealers, BC Sealer as compared with AH Plus using micro-computed tomographic (micro-CT) analysis. Materials and Methods Fifty-six extracted human maxillary incisors were instrumented and randomly divided into 4 groups of 14 teeth: 1A, gutta-percha, AH Plus retreated with chloroform; 1B, gutta-percha, AH Plus retreated without chloroform; 2A, gutta-percha, EndoSequence BC Sealer retreated with chloroform; 2B, gutta-percha, EndoSequence BC Sealer retreated without chloroform. Micro-CT scans were taken before and after obturation and retreatment and analyzed for the volume of residual material. The specimens were longitudinally sectioned and digitized images were taken with the dental operating microscope. Data was analyzed using an ANOVA and a post-hoc Tukey test. Fisher exact tests were performed to analyze the ability to regain patency. Results There was significantly less residual root canal filling material in the AH Plus groups retreated with chloroform as compared to the others. The BC Sealer samples retreated with chloroform had better results than those retreated without chloroform. Furthermore, patency could be re-established in only 14% of teeth in the BC Sealer without chloroform group. Conclusion The results of this study demonstrate that the BC Sealer group had significantly more residual filling material than the AH Plus group regardless of whether or not both sealers were retreated with chloroform. PMID:28194360

  3. Micro-computed tomographic analysis of the radial geometry of intrarenal artery-vein pairs in rats and rabbits: Comparison with light microscopy.

    PubMed

    Ngo, Jennifer P; Le, Bianca; Khan, Zohaib; Kett, Michelle M; Gardiner, Bruce S; Smith, David W; Melhem, Mayer M; Maksimenko, Anton; Pearson, James T; Evans, Roger G

    2017-08-10

    We assessed the utility of synchrotron-radiation micro-computed tomography (micro-CT) for quantification of the radial geometry of the renal cortical vasculature. The kidneys of nine rats and six rabbits were perfusion fixed and the renal circulation filled with Microfil. In order to assess shrinkage of Microfil, rat kidneys were imaged at the Australian Synchrotron immediately upon tissue preparation and then post fixed in paraformaldehyde and reimaged 24 hours later. The Microfil shrank only 2-5% over the 24 hour period. All subsequent micro-CT imaging was completed within 24 hours of sample preparation. After micro-CT imaging, the kidneys were processed for histological analysis. In both rat and rabbit kidneys, vascular structures identified in histological sections could be identified in two-dimensional (2D) micro-CT images from the original kidney. Vascular morphology was similar in the two sets of images. Radial geometry quantified by manual analysis of 2D images from micro-CT was consistent with corresponding data generated by light microscopy. However, due to limited spatial resolution when imaging a whole organ using contrast-enhanced micro-CT, only arteries ≥100 and ≥60 μm in diameter, for the rat and rabbit respectively, could be assessed. We conclude that it is feasible and valid to use micro-CT to quantify vascular geometry of the renal cortical circulation in both the rat and rabbit. However, a combination of light microscopic and micro-CT approaches are required to evaluate the spatial relationships between intrarenal arteries and veins over an extensive range of vessel size. © 2017 John Wiley & Sons Australia, Ltd.

  4. Comparison of alveolar ridge preservation methods using three-dimensional micro-computed tomographic analysis and two-dimensional histometric evaluation

    PubMed Central

    Park, Young-Seok; Kim, Sungtae; Oh, Seung-Hee; Park, Hee-Jung; Lee, Sophia; Lee, Young-Kyu; Heo, Min-Suk

    2014-01-01

    Purpose This study evaluated the efficacy of alveolar ridge preservation methods with and without primary wound closure and the relationship between histometric and micro-computed tomographic (CT) data. Materials and Methods Porcine hydroxyapatite with polytetrafluoroethylene membrane was implanted into a canine extraction socket. The density of the total mineralized tissue, remaining hydroxyapatite, and new bone was analyzed by histometry and micro-CT. The statistical association between these methods was evaluated. Results Histometry and micro-CT showed that the group which underwent alveolar preservation without primary wound closure had significantly higher new bone density than the group with primary wound closure (P<0.05). However, there was no significant association between the data from histometry and micro-CT analysis. Conclusion These results suggest that alveolar ridge preservation without primary wound closure enhanced new bone formation more effectively than that with primary wound closure. Further investigation is needed with respect to the comparison of histometry and micro-CT analysis. PMID:24944964

  5. Comparison of total variation algorithms for electrical impedance tomography.

    PubMed

    Zhou, Zhou; Sato dos Santos, Gustavo; Dowrick, Thomas; Avery, James; Sun, Zhaolin; Xu, Hui; Holder, David S

    2015-06-01

    The applications of total variation (TV) algorithms for electrical impedance tomography (EIT) have been investigated. The use of the TV regularisation technique helps to preserve discontinuities in reconstruction, such as the boundaries of perturbations and sharp changes in conductivity, which are unintentionally smoothed by traditional l2 norm regularisation. However, the non-differentiability of TV regularisation has led to the use of different algorithms. Recent advances in TV algorithms such as the primal dual interior point method (PDIPM), the linearised alternating direction method of multipliers (LADMM) and the spilt Bregman (SB) method have all been demonstrated successful EIT applications, but no direct comparison of the techniques has been made. Their noise performance, spatial resolution and convergence rate applied to time difference EIT were studied in simulations on 2D cylindrical meshes with different noise levels, 2D cylindrical tank and 3D anatomically head-shaped phantoms containing vegetable material with complex conductivity. LADMM had the fastest calculation speed but worst resolution due to the exclusion of the second-derivative; PDIPM reconstructed the sharpest change in conductivity but with lower contrast than SB; SB had a faster convergence rate than PDIPM and the lowest image errors.

  6. Microcomputers in Science Education.

    ERIC Educational Resources Information Center

    Spraggs, Laurence D.

    1984-01-01

    Encourages the use of microcomputers in the science classroom, providing information on uses (e.g., simulation and modeling, drill and practice programs, interface with lab equipment, conceptual data analysis, database management, and word processing), logistics, equipment, and software. (DMM)

  7. Microcomputers in Science Education.

    ERIC Educational Resources Information Center

    Spraggs, Laurence D.

    1984-01-01

    Encourages the use of microcomputers in the science classroom, providing information on uses (e.g., simulation and modeling, drill and practice programs, interface with lab equipment, conceptual data analysis, database management, and word processing), logistics, equipment, and software. (DMM)

  8. Microcomputer Technical Overview.

    ERIC Educational Resources Information Center

    Moursund, David

    1984-01-01

    A rationale for understanding computer operations is given. An overview of microcomputer technology, including an introduction to computer software, hardware, input and output devices, central processing unit, primary and secondary memory, and videodisk interactive systems is presented. (Author/BS)

  9. Microcomputers in Library Education.

    ERIC Educational Resources Information Center

    Large, J. A.; Guy, R. F.

    1982-01-01

    Develops a rationale for using microcomputers in the professional education of librarians in such courses as online searching and subject indexing and describes the use of computer assisted instruction at the College of Librarianship in Wales. (JJD)

  10. Microcomputers in Training Programs.

    ERIC Educational Resources Information Center

    Mason, Emanuel J.

    1982-01-01

    Factors in selecting and using microcomputers for school, business, and industry are outlined. Considerations include: (1) computer literacy; (2) networking; (3) training of handicapped people; (4) training and work applications; and (5) technology developments. (FG)

  11. Comparison of three retreatment techniques with ultrasonic activation in flattened canals using micro-computed tomography and scanning electron microscopy.

    PubMed

    Bernardes, R A; Duarte, M A H; Vivan, R R; Alcalde, M P; Vasconcelos, B C; Bramante, C M

    2015-08-17

    To use micro-CT to quantitatively evaluate the amount of residual filling material after using several techniques to remove root fillings with and without ultrasonic activation and to analyse the cleanliness of the root canal walls and dentine tubules with scanning electron microscopy (SEM). The root canals of one hundred and eight human mandibular incisors were selected and instrumented with rotary files using the BioRace system up to file size 40, .04 taper. After instrumentation, the teeth were filled using a hybrid technique with gutta-percha and sealer then divided into three groups according to the method used for removing the root filling: G1-Reciproc (using only instrument R50), G2-ProTaper Universal retreatment system and G3-Manual (hand files and Gates-Glidden burs). All groups were divided into two subgroups depending on whether ultrasonic agitation was used with the irrigants. Micro-CT scans were taken before and after removal of the filling material to detect residual material in the canal. After micro-CT analysis, the roots were cut in half, imaged by SEM and scored based on the amount of surface covered by root filling remnants. The data were analysed statistically using a significance level of 5%. All groups had retained material in the root canals after instrumentation. The Reciproc method was associated with less retained material than the ProTaper and Manual methods. Ultrasonic activation significantly reduced the amount of residual root filling in all groups (P < 0.05). None of the instrumentation methods were able to completely remove root filling material. Ultrasonic activation improved the removal of root filling material in all groups. © 2015 International Endodontic Journal. Published by John Wiley & Sons Ltd.

  12. The Use of Micro-Computed Tomography to Determine the Accuracy of 2 Electronic Apex Locators and Anatomic Variations Affecting Their Precision.

    PubMed

    Piasecki, Lucila; Carneiro, Everdan; da Silva Neto, Ulisses Xavier; Westphalen, Vânia Portela Ditzel; Brandão, Christian Giampietro; Gambarini, Gianluca; Azim, Adham A

    2016-08-01

    The aim of this study was to compare the accuracy of 2 electronic apex locators (EALs), Apex ID (SybronEndo, Glendora, CA) and Root ZX (J. Morita, Tokyo, Japan), by means of micro-computed tomographic (micro-CT) imaging and to determine anatomic variations that may affect their accuracy. The root canal length (RCL) and working length (WL) of 33 single-rooted premolars were measured using a visual method, 3-dimensional micro-CT reconstructions, and 2 different EALs. Two different measurements were recorded for each EAL: at the "APEX/0.0" mark and at the "0.5" mark. The WL was determined using 2 different methods: method 1: at the "0.5 mark" of the apex locator and method 2: subtracting 0.5 mm from the "APEX/0.0" mark. The precision of measurements was compared with those recorded by micro-CT imaging. Apical foramen (AF) position and diameter, apical constriction (AC) diameter, distance between the AC and the AF, and the presence/absence of accessory canals were recorded from the micro-CT scans, and their correlation to the accuracy of EALs was determined. There was no statistically significant difference in the RCL measurements by any of the different methods. There was a statistically significant difference in the WL recorded by micro-CT imaging compared with those by the visual method and at the "APEX/0.0 mark" - 0.5 mm (P = .031). There was no difference in the measurements acquired by any of the EALs. The "APEX/0.0 mark" - 0.5 mm was less accurate than the "0.5" mark. However, the results were not statistically significant (P > .05). The position of the AF and the AC-AF distance affected the accuracy of the RCL (P = .003) and the "0.5" mark (P = .013). Root ZX and Apex ID are equally precise in determining the RCL and WL. The "0.5" mark can be used to determine the WL with high precision. Some anatomic variations may influence the accuracy of EALs. Published by Elsevier Inc.

  13. The Perils of Personals: Microcomputers in Libraries.

    ERIC Educational Resources Information Center

    Carlson, David H.

    1985-01-01

    Explores microcomputer revolution and assesses role of microcomputers in libraries. Highlights include characteristics of three types of computers (mainframes, minicomputers, microcomputers); hardware limitations of microcomputers (storage capacity, processing speed); advancing technology; the local area network; software problems; and…

  14. Performance comparison of different metrics for spectroscopic optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Jaedicke, Volker; Agcaer, Semih; Robles, Francisco E.; Steinert, Marian; Jones, David; Goebel, Sebastian; Gerhardt, Nils C.; Welp, Hubert; Hofmann, Martin R.

    2014-03-01

    When light interacts with a scattering medium, the spectrum of the incident light undergoes changes that are dependent on the size of the scatterers in the medium. Spectroscopic Optical Coherence Tomography (S-OCT) is a method that can be used to ascertain the resulting spatially-dependent spectral information. In fact, S-OCT is sensitive to structures that are below the spatial resolution of the system, making S-OCT a promising tool for diagnosing many diseases and biological processes that change tissue structure, like cancer. The most important signal processing steps for S-OCT are the depth-resolved spectral analysis and the calculation of a spectroscopic metric. While the former calculates the spectra from the raw OCT data, the latter analyzes the information content of the processed depth-resolved spectra. We combine the Dual Window spectral analysis with different spectroscopic metrics, which are used as an input to colorize intensity based images. These metrics include the spectral center of mass method, principal component (PCA) and phasor analysis. To compare the performance of the metrics in a quantitative manner, we use a cluster algorithm to calculate efficiencies for all methods. For this purpose we use phantom samples which contain areas of microspheres of different sizes. Our results demonstrate that PCA and phasor analysis have the highest efficiencies, and can clearly separate these areas. Finally we will present data from cartilage tissue under static load in vitro. These preliminary results show that S-OCT can generate additional contrast in biological tissue in comparison to the pure intensity based images.

  15. Probing Microcomputer-Based Laboratories.

    ERIC Educational Resources Information Center

    Lam, Tom

    1985-01-01

    Microcomputer-based laboratories (MBLs) refer to a laboratory where a microcomputer gathers and displays data directly from the environment. Program listings for a response timer (using game paddles) to illustrate the nature of MBLs are presented. (JN)

  16. Physical properties of root cementum: Part 25. Extent of root resorption after the application of light and heavy buccopalatal jiggling forces for 12 weeks: A microcomputed tomography study.

    PubMed

    Eross, Edina; Turk, Tamer; Elekdag-Turk, Selma; Cakmak, Fethiye; Jones, Allan S; Végh, András; Papadopoulou, Alexandra K; Darendeliler, M Ali

    2015-06-01

    The aims of this study were to evaluate with microcomputed tomography the orthodontically induced inflammatory root resorption in premolars caused by buccopalatal jiggling movement with light and heavy forces and to compare it with the resorption caused by equivalent but continuous buccal forces. The sample consisted of 60 maxillary first premolars collected from 30 patients (15 girls, 15 boys; ages, 13-18 years) who required orthodontic treatment with extractions. They were divided into 3 groups of 10 patients. Light (25 g) or heavy (225 g) buccal tipping orthodontic forces were randomly assigned on the maxillary right or left quadrant with either continuous buccal (positive controls) or buccopalatal jiggling forces for 12 weeks. At the end of the experimental period, the teeth were carefully extracted and processed for 3-dimensional imaging and volumetric evaluations of resorption craters. Data were analyzed with Wilcoxon signed rank tests. There was no statistically significant difference between positive control light (P = 0.0173) and heavy (P = 0.0173) continuous forces and jiggling forces for both force magnitudes. However, statistically significant differences were observed between heavy and light jiggling forces (P = 0.038), with heavy jiggling forces causing greater total root resorption than light jiggling forces. Light and heavy jiggling forces in the buccopalatal direction did not cause significantly different amounts of root resorption when compared with continuous forces of the same magnitude. On the other hand, light jiggling forces resulted in less root resorption than heavy jiggling forces. Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.

  17. Beam hardening artifacts in micro-computed tomography scanning can be reduced by X-ray beam filtration and the resulting images can be used to accurately measure BMD.

    PubMed

    Meganck, Jeffrey A; Kozloff, Kenneth M; Thornton, Michael M; Broski, Stephen M; Goldstein, Steven A

    2009-12-01

    Bone mineral density (BMD) measurements are critical in many research studies investigating skeletal integrity. For pre-clinical research, micro-computed tomography (microCT) has become an essential tool in these studies. However, the ability to measure the BMD directly from microCT images can be biased by artifacts, such as beam hardening, in the image. This three-part study was designed to understand how the image acquisition process can affect the resulting BMD measurements and to verify that the BMD measurements are accurate. In the first part of this study, the effect of beam hardening-induced cupping artifacts on BMD measurements was examined. In the second part of this study, the number of bones in the X-ray path and the sampling process during scanning was examined. In the third part of this study, microCT-based BMD measurements were compared with ash weights to verify the accuracy of the measurements. The results indicate that beam hardening artifacts of up to 32.6% can occur in sample sizes of interest in studies investigating mineralized tissue and affect mineral density measurements. Beam filtration can be used to minimize these artifacts. The results also indicate that, for murine femora, the scan setup can impact densitometry measurements for both cortical and trabecular bone and morphologic measurements of trabecular bone. Last, when a scan setup that minimized all of these artifacts was used, the microCT-based measurements correlated well with ash weight measurements (R(2)=0.983 when air was excluded), indicating that microCT can be an accurate tool for murine bone densitometry.

  18. Cement Thickness of Inlay Restorations Made of Lithium Disilicate, Polymer-Infiltrated Ceramic and Nano-Ceramic CAD/CAM Materials Evaluated Using 3D X-Ray Micro-Computed Tomography.

    PubMed

    Uzgur, Recep; Ercan, Ertuğrul; Uzgur, Zeynep; Çolak, Hakan; Yalçın, Muhammet; Özcan, Mutlu

    2016-08-12

    To evaluate the marginal and internal cement thicknesses of inlay restorations made of various CAD/CAM materials using 3D X-ray micro-computed tomography (micro-CT) technique. Caries-free extracted mandibular molars (N = 30) with similar size were randomly assigned to three groups (N = 10 per group). Mesio-occlusal-distal (MOD) cavities were prepared, and inlay restorations were obtained by milling out CAD/CAM materials namely, (a) IPS: monolithic lithium disilicate (control), (b) VE: polymer-infiltrated ceramic, and (c) CS: nano-ceramic using a CAM unit. Marginal and internal cement thicknesses were measured using 3D micro-CT. Data were analyzed using 1-way ANOVA and Tukey's tests (alpha = 0.05). The mean marginal and internal cement thickness were not significant in all inlay materials (p > 0.05). Mean marginal cement thickness (μm) was the lowest for the IPS group (67.54 ± 10.16) followed by VE (84.09 ± 3.94) and CS (95.18 ± 10.58) (p > 0.05). The internal cement thickness (μm) was the lowest in the CS group (54.85 ± 6.94) followed by IPS (60.58 ± 9.22) and VE (77.53 ± 12.13) (p > 0.05). Marginal and internal cement thicknesses of MOD inlays made of monolithic lithium disilicate, polymer-infiltrated ceramic, and nano-ceramic CAD/CAM materials were similar and all less than 100 μm, which could be considered clinically acceptable. MOD inlays made of different CAD/CAM materials presented similar cement thickness, less than 100 μm. © 2016 by the American College of Prosthodontists.

  19. Beam Hardening Artifacts in Micro-Computed Tomography Scanning can be Reduced by X-ray Beam Filtration and the Resulting Images can be used to Accurately Measure BMD

    PubMed Central

    Meganck, Jeffrey A.; Kozloff, Kenneth M.; Thornton, Michael M.; Broski, Stephen M.; Goldstein, Steven A.

    2009-01-01

    Bone mineral density (BMD) measurements are critical in many research studies investigating skeletal integrity. For preclinical research, micro-computed tomography (μCT) has become an essential tool in these studies. However, the ability to measure the BMD, directly from μCT images can be biased by artifacts such as beam hardening, in the image. This three-part study was designed to understand how the image acquisition process can affect the resulting BMD measurements and to verify that the BMD measurements are accurate. In the first part of this study, the effect of beam hardening-induced cupping artifacts on BMD measurements was examined. In the second part of this study, the number of bones in the X-ray path and the sampling process during scanning was examined. In the third part of this study, μCT-based BMD measurements were compared with ash weights to verify the accuracy of the measurements. The results indicate that beam hardening artifacts of up to 32.6% can occur in sample sizes of interest in studies investigating mineralized tissue and affect mineral density measurements. Beam filtration can be used to minimize these artifacts. The results also indicate that, for murine femora, the scan setup can impact densitometry measurements for both cortical and trabecular bone and morphologic measurements of trabecular bone. Last, when a scan setup that minimized all of these artifacts was used, the μCT based measurements correlated used well with ash weight measurements (R2 = 0.983 when air was excluded), indicating that μCT can be an accurate tool for murine bone densitometry. PMID:19651256

  20. The use of a novel cleaning closed suction system reduces the volume of secretions within the endotracheal tube as assessed by micro-computed tomography: a randomized clinical trial.

    PubMed

    Coppadoro, Andrea; Bellani, Giacomo; Bronco, Alfio; Lucchini, Alberto; Bramati, Simone; Zambelli, Vanessa; Marcolin, Roberto; Pesenti, Antonio

    2015-12-01

    Early after intubation, a layer of biofilm covers the inner lumen of the endotracheal tube (ETT). Cleaning the ETT might prevent airways colonization by pathogens, reduce resistance to airflow, and decrease sudden ETT obstruction. We investigated the effectiveness of a cleaning closed suction system in maintaining the endotracheal tube free from secretions. We conducted a single center, randomized controlled trial, in the general intensive care unit of a tertiary-level university hospital. We enrolled 40 adult critically ill patients expected to remain intubated for more than 48 h, within 24 h from intubation. Patients were randomized to receive three ETT cleaning maneuvers/day using a novel device (Airway Medix Closed Suction System™, cleaning group) or to standard care (no ETT cleaning, standard closed suction, control group). After extubation, the amount of secretions in the ETTs was measured by micro-computed tomography. The volume of secretions in the ETTs from the cleaning group was lower than controls (0.081 [0.021-0.306] vs. 0.568 [0.162-0.756] mL, p = 0.001), corresponding to a cross-sectional area reduction six times lower (1[0-3] vs. 6 [2-10] %, p = 0.001). In a subset of 16 patients, the resistance to airflow tended to be lower after 1 day of treatment (p = 0.063) and was lower after 2 days (0.024), while no difference was present at enrollment (p = 0.922). ETT colonization did not differ between the two groups. The use of a novel cleaning closed suction system proved to be effective in reducing secretions present in the ETT after extubation, possibly reducing resistance to airflow during intubation. clinicaltrials.gov NCT01912105.

  1. Biocompatibility property of 100% strontium-substituted SiO2 -Al2 O3 -P2 O5 -CaO-CaF2 glass ceramics over 26 weeks implantation in rabbit model: Histology and micro-Computed Tomography analysis.

    PubMed

    Basu, Bikramjit; Sabareeswaran, A; Shenoy, S J

    2015-08-01

    One of the desired properties for any new biomaterial composition is its long-term stability in a suitable animal model and such property cannot be appropriately assessed by performing short-term implantation studies. While hydroxyapatite (HA) or bioglass coated metallic biomaterials are being investigated for in vivo biocompatibility properties, such study is not extensively being pursued for bulk glass ceramics. In view of their inherent brittle nature, the implant stability as well as impact of long-term release of metallic ions on bone regeneration have been a major concern. In this perspective, the present article reports the results of the in vivo implantation experiments carried out using 100% strontium (Sr)-substituted glass ceramics with the nominal composition of 4.5 SiO2 -3Al2 O3 -1.5P2 O5 -3SrO-2SrF2 for 26 weeks in cylindrical bone defects in rabbit model. The combination of histological and micro-computed tomography analysis provided a qualitative and quantitative understanding of the bone regeneration around the glass ceramic implants in comparison to the highly bioactive HA bioglass implants (control). The sequential polychrome labeling of bone during in vivo osseointegration using three fluorochromes followed by fluorescence microscopy observation confirmed homogeneous bone formation around the test implants. The results of the present study unequivocally confirm the long-term implant stability as well as osteoconductive property of 100% Sr-substituted glass ceramics, which is comparable to that of a known bioactive implant, that is, HA-based bioglass.

  2. Integrating Microcomputing into Preparation Programs.

    ERIC Educational Resources Information Center

    Peseau, Bruce A.

    This paper presents an example of a course syllabus that integrates the use of microcomputers as part of a recommendation that administrators become specialists in microcomputing in their preparatory programs. Computers' dramatically reduced costs, in combination with increased power, has made them easily available in the form of microcomputers.…

  3. Functional morphology of the copulatory organs of a reed beetle and a shining leaf beetle (Coleoptera: Chrysomelidae: Donaciinae, Criocerinae) using X-ray micro-computed tomography *

    PubMed Central

    Schmitt, Michael; Uhl, Gabriele

    2015-01-01

    Abstract For more than 100 years it has been known that the sclerotised median lobe of beetles harbours a membranous structure (the "internal sac" or "endophallus") which is everted during copula inside the female genital tract. In order to explore the functional role of this structure and those associated with it, we cryofixed copulating pairs of Donacia semicuprea and Lilioceris lilii and studied the relative position of the elements of the copulatory apparatus of males and females by micro-computer-tomography. We found that the everted endophallus fills the lumen of the bursa copulatrix completely. Our data suggest that in Lilioceris lilii the tip of the sclerotised distal part of the ejaculatory duct, the flagellum, is positioned exactly over the opening of the spermathecal duct inside the bursa copulatrix. The mouth of the bursa copulatrix in Donacia semicuprea is armed with a strong muscle ring, and the whole wall of the bursa is covered externally with a layer of muscle fibres. These morphological differences correspond with differences in mating behaviour: In reed beetles (Donaciinae), females seemingly can control mating to a higher degree than in lily beetles (Lilioceris spp.). PMID:26798321

  4. Localization of Metal Electrodes in the Intact Rat Brain Using Registration of 3D Microcomputed Tomography Images to a Magnetic Resonance Histology Atlas1,2,3

    PubMed Central

    Borg, Jana Schaich; Vu, Mai-Anh; Badea, Cristian; Badea, Alexandra; Johnson, G. Allan

    2015-01-01

    Abstract Simultaneous neural recordings taken from multiple areas of the rodent brain are garnering growing interest because of the insight they can provide about spatially distributed neural circuitry. The promise of such recordings has inspired great progress in methods for surgically implanting large numbers of metal electrodes into intact rodent brains. However, methods for localizing the precise location of these electrodes have remained severely lacking. Traditional histological techniques that require slicing and staining of physical brain tissue are cumbersome and become increasingly impractical as the number of implanted electrodes increases. Here we solve these problems by describing a method that registers 3D computed tomography (CT) images of intact rat brains implanted with metal electrode bundles to a magnetic resonance imaging histology (MRH) atlas. Our method allows accurate visualization of each electrode bundle’s trajectory and location without removing the electrodes from the brain or surgically implanting external markers. In addition, unlike physical brain slices, once the 3D images of the electrode bundles and the MRH atlas are registered, it is possible to verify electrode placements from many angles by “reslicing” the images along different planes of view. Furthermore, our method can be fully automated and easily scaled to applications with large numbers of specimens. Our digital imaging approach to efficiently localizing metal electrodes offers a substantial addition to currently available methods, which, in turn, may help accelerate the rate at which insights are gleaned from rodent network neuroscience. PMID:26322331

  5. Anatomy of the murine and human cochlea visualized at the cellular level by synchrotron-radiation-based micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Müller, B.; Lareida, A.; Beckmann, F.; Diakov, G. M.; Kral, F.; Schwarm, F.; Stoffner, R.; Gunkel, A. R.; Glueckert, R.; Schrott-Fischer, A.; Fischer, J.; Andronache, A.; Freysinger, W.

    2006-08-01

    Diseases of the hearing organ and impairment affect a significant fraction of population. Therefore, the hearing organ embedded as a helical structure in the cochlea within the hardest human osseous structure inside the petrous bone is intensively investigated. Currently, studies of the cochlea with true micrometer resolution or better are destructive. Membranes and three-dimensional vessel structures of post-mortem explanted human cochlea were only visualized with limited spatial resolution or deformed anatomical features resulting from preparation artifacts. We have applied a preparation and staining protocol developed for electron microscopy, which allows the visualization and quantification of a great variety of soft-tissue structures including the Reissner's membrane, the tectorial membrane, basilar membrane, modiolus, lamina radialis, and Nuel's space by the use of synchrotron-radiation-based micro computed tomography at the beamline BW 2 (HASYLAB at DESY). The level of detail can be even improved by the application of sophisticated computer vision tools, which enables the extraction of the vascular tree down to the capillaries and of the course of nerve fibers as well as the topology of the osseous lamina radialis, which assembles the nerve fibers from the hair-cells to the ganglia in the center of the cochlea, the modiolus. These non-destructively obtained three-dimensional data are principal for the refined understanding of the hearing process by membranes morphologies and further anatomical features at the cellular level and for teaching purposes in medical curricula.

  6. Consider a microcomputer.

    PubMed

    Slubowski, M A

    1982-01-01

    Although computers have proven to be effective tools in managing the administrative aspects of a medical group practice, many groups are hesitant to invest in this new technology. They are concerned about huge capital expenditures for equipment, the consequences of the implementation period, and failures that many groups are reported to have experienced in this endeavor. Microcomputers are a low-cost method through which a medical group can experiment with computerized information systems without taking the risk of total conversion from a manual to an automated system. The experience of the Sterling Heights Center in implementing a microcomputer is helpful to any group considering such a system.

  7. Anti-angiogenic therapy affects the relationship between tumor vascular structure and function: A correlation study between micro-computed tomography angiography and dynamic contrast enhanced MRI.

    PubMed

    Kim, Eugene; Kim, Jana; Maelandsmo, Gunhild Mari; Johansen, Berit; Moestue, Siver Andreas

    2017-10-01

    To compare the effects of two anti-angiogenic drugs, bevacizumab and a cytosolic phospholipase A2-α inhibitor (AVX235), on the relationship between vascular structure and dynamic contrast enhanced (DCE)-MRI measurements in a patient-derived breast cancer xenograft model. Mice bearing MAS98.12 tumors were randomized into three groups: bevacizumab-treated (n = 9), AVX235-treated (n = 9), and control (n = 8). DCE-MRI was performed pre- and post-treatment. Median initial area under the concentration-time curve (IAUC60 ) and volume transfer constant (K(trans) ) were computed for each tumor. Tumors were excised for ex vivo micro-CT (computed tomography) angiography, from which the vascular surface area (VSA) and fractional blood volume (FBV) were computed. Spearman correlation coefficients (ρ) were computed to evaluate the associations between the DCE-MRI and micro-CT parameters. With the groups pooled, IAUC60 and K(trans) correlated significantly with VSA (ρ = 0.475 and 0.527; P = 0.019 and 0.008). There were no significant correlations within the control group. There were various significant correlations within the treatment groups, but the correlations in the bevacizumab group were of opposite sign, for example, K(trans) versus FBV: AVX235, ρ = 0.800 (P = 0.014); bevacizumab, ρ = -0.786 (P = 0.023). DCE-MRI measurements can highly depend on vascular structure. The relationship between vascular structure and function changed markedly after anti-angiogenic treatment. Magn Reson Med 78:1513-1522, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

  8. A Comparison of Third Grade Student Performance in Division of Whole Numbers Using a Microcomputer Drill Program and a Print Drill Program.

    ERIC Educational Resources Information Center

    Leigh, Robert K.; And Others

    Compared were the performance of third grade pupils on division of whole numbers using a commercial microcomputer drill program (Milliken Publishing Company Math Sequence) with the performance of another group using printed drill materials (mimeographed sheets of 50 problems from each level of the computer drill program). Using a matched pairs…

  9. Microcomputer Software Technician Curriculum.

    ERIC Educational Resources Information Center

    EASTCONN Regional Educational Services Center, North Windham, CT.

    This curriculum guide, developed for high schools in Connecticut, outlines a 4-year program for training microcomputer software technicians. Following a list of nine general objectives of the program, the guide provides a list of competencies that students are expected to develop in each of the courses of the 4-year program. The guide then…

  10. Storage Media for Microcomputers.

    ERIC Educational Resources Information Center

    Trautman, Rodes

    1983-01-01

    Reviews computer storage devices designed to provide additional memory for microcomputers--chips, floppy disks, hard disks, optical disks--and describes how secondary storage is used (file transfer, formatting, ingredients of incompatibility); disk/controller/software triplet; magnetic tape backup; storage volatility; disk emulator; and…

  11. Microcomputers in Special Education.

    ERIC Educational Resources Information Center

    Freeze, D. Richard

    1988-01-01

    Microcomputer applications for four areas of special education are discussed: (1) information management and decision making for administrators; (2) characteristics of quality second generation computer assisted instructional programs for teachers; (3) communications and early prostheses advances for educators of the severely and multiply…

  12. Troubleshooting the Classroom Microcomputer.

    ERIC Educational Resources Information Center

    Grandgenett, Neal; Sullivan, Kimber

    1990-01-01

    Provides a checklist for troubleshooting malfunctions in classroom microcomputers and explains steps involved for each component. Areas that are addressed include tools to have available; checking computer cables; disk drives; the computer itself; the monitor, or receiver; printers; and software. (LRW)

  13. Microcomputers in Education.

    ERIC Educational Resources Information Center

    Anderson, Cheryl A.

    Designed to answer basic questions educators have about microcomputer hardware and software and their applications in teaching, this paper describes the revolution in computer technology that has resulted from the development of the microchip processor and provides information on the major computer components; i.e.; input, central processing unit,…

  14. Storage Media for Microcomputers.

    ERIC Educational Resources Information Center

    Trautman, Rodes

    1983-01-01

    Reviews computer storage devices designed to provide additional memory for microcomputers--chips, floppy disks, hard disks, optical disks--and describes how secondary storage is used (file transfer, formatting, ingredients of incompatibility); disk/controller/software triplet; magnetic tape backup; storage volatility; disk emulator; and…

  15. Microcomputers in Business Education.

    ERIC Educational Resources Information Center

    Muscat, Eugene

    1980-01-01

    This article acquaints business educators with the equipment, terminology, and the wide range of applications microcomputers have in business education programs. Areas examined include hardware, software, computer-assisted instruction (drill and practice, simulation, and tutorial), computer-managed instruction, and word processing. (CT)

  16. Teaching with Microcomputers.

    ERIC Educational Resources Information Center

    Gerber, Michael M.

    1986-01-01

    The introduction to the special section on microcomputers in special education reviews the trend toward increasing computer use, raises such issues as the need for special educators to provide leadership in the use of computers for individualized instruction, and summarizes remaining articles in the section. (DB)

  17. Three-dimensional visualisation of the internal anatomy of the sparrowhawk (Accipiter nisus) forelimb using contrast-enhanced micro-computed tomography.

    PubMed

    Bribiesca-Contreras, Fernanda; Sellers, William I

    2017-01-01

    Gross dissection is a widespread method for studying animal anatomy, despite being highly destructive and time-consuming. X-ray computed tomography (CT) has been shown to be a non-destructive alternative for studying anatomical structures. However, in the past it has been limited to only being able to visualise mineralised tissues. In recent years, morphologists have started to use traditional X-ray contrast agents to allow the visualisation of soft tissue elements in the CT context. The aim of this project is to assess the ability of contrast-enhanced micro-CT (μCT) to construct a three-dimensional (3D) model of the musculoskeletal system of the bird wing and to quantify muscle geometry and any systematic changes due to shrinkage. We expect that this reconstruction can be used as an anatomical guide to the sparrowhawk wing musculature and form the basis of further biomechanical analysis of flight. A 3% iodine-buffered formalin solution with a 25-day staining period was used to visualise the wing myology of the sparrowhawk (Accipiter nisus). μCT scans of the wing were taken over the staining period until full penetration of the forelimb musculature by iodine was reached. A 3D model was reconstructed by manually segmenting out the individual elements of the avian wing using 3D visualisation software. Different patterns of contrast were observed over the duration of the staining treatment with the best results occurring after 25 days of staining. Staining made it possible to visualise and identify different elements of the soft tissue of the wing. Finally, a 3D reconstruction of the musculoskeletal system of the sparrowhawk wing is presented and numerical data of muscle geometry is compared to values obtained by dissection. Contrast-enhanced μCT allows the visualisation and identification of the wing myology of birds, including the smaller muscles in the hand, and provides a non-destructive way for quantifying muscle volume with an accuracy of 96.2%. By combining

  18. Three-dimensional visualisation of the internal anatomy of the sparrowhawk (Accipiter nisus) forelimb using contrast-enhanced micro-computed tomography

    PubMed Central

    2017-01-01

    Background Gross dissection is a widespread method for studying animal anatomy, despite being highly destructive and time-consuming. X-ray computed tomography (CT) has been shown to be a non-destructive alternative for studying anatomical structures. However, in the past it has been limited to only being able to visualise mineralised tissues. In recent years, morphologists have started to use traditional X-ray contrast agents to allow the visualisation of soft tissue elements in the CT context. The aim of this project is to assess the ability of contrast-enhanced micro-CT (μCT) to construct a three-dimensional (3D) model of the musculoskeletal system of the bird wing and to quantify muscle geometry and any systematic changes due to shrinkage. We expect that this reconstruction can be used as an anatomical guide to the sparrowhawk wing musculature and form the basis of further biomechanical analysis of flight. Methods A 3% iodine-buffered formalin solution with a 25-day staining period was used to visualise the wing myology of the sparrowhawk (Accipiter nisus). μCT scans of the wing were taken over the staining period until full penetration of the forelimb musculature by iodine was reached. A 3D model was reconstructed by manually segmenting out the individual elements of the avian wing using 3D visualisation software. Results Different patterns of contrast were observed over the duration of the staining treatment with the best results occurring after 25 days of staining. Staining made it possible to visualise and identify different elements of the soft tissue of the wing. Finally, a 3D reconstruction of the musculoskeletal system of the sparrowhawk wing is presented and numerical data of muscle geometry is compared to values obtained by dissection. Discussion Contrast-enhanced μCT allows the visualisation and identification of the wing myology of birds, including the smaller muscles in the hand, and provides a non-destructive way for quantifying muscle volume

  19. 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.

  20. Comparison of two image reconstruction algorithms for microwave tomography

    NASA Astrophysics Data System (ADS)

    Fhager, A.; Persson, M.

    2005-06-01

    Two image reconstruction algorithms for microwave tomography are compared and contrasted. One is a general, gradient-based minimization algorithm. The other is the chirp pulse microwave computed tomography (CP-MCT) method, which is a highly computationally efficient reconstruction method but also a method best suited for low contrasts. The results of the simulations show that when imaging high-contrast objects, such as a breast cancer tumor, reconstructions made are comparable to results from the minimization algorithm below a contrast of about 10%. The simulations, however, show that the reconstructions made by the CP-MCT method are very robust to noise. The reconstruction of the conductivity using the minimization algorithm, on the other hand, is very sensitive to the level of noise. In spite of a strong degradation in the conductivity reconstructions, the corresponding permittivity reconstructions do not show the same sensitivity to the noise level.

  1. Efficacy of Needle, Ultrasonic, and Endoactivator Irrigation and Photon-Induced Photoacoustic Streaming in Removing Calcium Hydroxide from the Main Canal and Isthmus: An In Vitro Micro-Computed Tomography and Scanning Electron Microscopy Study.

    PubMed

    Li, Dongxia; Jiang, Shan; Yin, Xingzhe; Chang, Jeffrey Wen Wei; Ke, Jie; Zhang, Chengfei

    2015-06-01

    The aim of this in vitro study was to use high-resolution micro-computed tomography (micro-CT) and scanning electron microscopy (SEM) to compare the efficacy of four irrigation techniques [needle, ultrasonic, EndoActivator, and photon-induced photoacoustic streaming (PIPS)] in removing calcium hydroxide (Ca[OH]2) from the root canal and isthmus of maxillary premolars. Twenty-four maxillary first premolars were selected based on the presence of isthmus regions on micro-CT scans. Root canals were instrumented with an F2 file using ProTaper rotary instruments and filled with Ca(OH)2 paste. Samples were stored at 37°C and 100% humidity for 1 week and randomly divided into four groups (n=6 each), according to irrigation technique. Samples were scanned with micro-CT before instrumentation, after Ca(OH)2 filling, and after irrigation. Ca(OH)2 reduction in the coronal, middle, and apical thirds and in the isthmus were assessed with three-dimensional image analysis. Next, specimens were split longitudinally, and canal walls were examined with SEM for Ca(OH)2 residues. Data were statistically evaluated with the Kruskal-Wallis and Mann-Whitney tests (p=0.05). The PIPS and ultrasonic groups showed greater Ca(OH)2 reduction in the apical third and higher cleanliness of the isthmus than the EndoActivator and needle irrigation groups (p<0.05). Ca(OH)2 residue scores in the PIPS and ultrasonic groups were significantly lower than those in the EndoActivator and needle groups in all regions of the root canals (p<0.05). There was no significant difference between PIPS and ultrasonic groups (p>0.05), or between EndoActivator and needle groups (p>0.05). PIPS and ultrasonic irrigation more effectively removed Ca(OH)2 from the main canal and isthmus in maxillary premolars than did EndoActivator or needle irrigation.

  2. Comparison of orbital volume obtained by tomography and rapid prototyping.

    PubMed

    Roça, Guilherme Berto; Foggiatto, José Aguiomar; Ono, Maria Cecilia Closs; Ono, Sergio Eiji; da Silva Freitas, Renato

    2013-11-01

    This study aims to compare orbital volume obtained by helical tomography and rapid prototyping. The study sample was composed of 6 helical tomography scans. Eleven healthy orbits were identified to have their volumes measured. The volumetric analysis with the helical tomography utilized the same protocol developed by the Plastic Surgery Unit of the Federal University of Paraná. From the CT images, 11 prototypes were created, and their respective volumes were analyzed in 2 ways: using software by SolidWorks and by direct analysis, when the prototype was filled with saline solution. For statistical analysis, the results of the volumes of the 11 orbits were considered independent. The average orbital volume measurements obtained by the method of Ono et al was 20.51 cm, the average obtained by the SolidWorks program was 20.64 cm, and the average measured using the prototype method was 21.81 cm. The 3 methods demonstrated a strong correlation between the measurements. The right and left orbits of each patient had similar volumes. The tomographic method for the analysis of orbital volume using the Ono protocol yielded consistent values, and by combining this method with rapid prototyping, both reliability validations of results were enhanced.

  3. Comparison of Tissue Density in Hounsfield Units in Computed Tomography and Cone Beam Computed Tomography.

    PubMed

    Varshowsaz, Masoud; Goorang, Sepideh; Ehsani, Sara; Azizi, Zeynab; Rahimian, Sepideh

    2016-03-01

    Bone quality and quantity assessment is one of the most important steps in implant treatment planning. Different methods such as computed tomography (CT) and recently suggested cone beam computed tomography (CBCT) with lower radiation dose and less time and cost are used for bone density assessment. This in vitro study aimed to compare the tissue density values in Hounsfield units (HUs) in CBCT and CT scans of different tissue phantoms with two different thicknesses, two different image acquisition settings and in three locations in the phantoms. Four different tissue phantoms namely hard tissue, soft tissue, air and water were scanned by three different CBCT and a CT system in two thicknesses (full and half) and two image acquisition settings (high and low kVp and mA). The images were analyzed at three sites (middle, periphery and intermediate) using eFilm software. The difference in density values was analyzed by ANOVA and correction coefficient test (P<0.05). There was a significant difference between density values in CBCT and CT scans in most situations, and CBCT values were not similar to CT values in any of the phantoms in different thicknesses and acquisition parameters or the three different sites. The correction coefficients confirmed the results. CBCT is not reliable for tissue density assessment. The results were not affected by changes in thickness, acquisition parameters or locations.

  4. Comparison of Tissue Density in Hounsfield Units in Computed Tomography and Cone Beam Computed Tomography

    PubMed Central

    Varshowsaz, Masoud; Goorang, Sepideh; Ehsani, Sara; Azizi, Zeynab; Rahimian, Sepideh

    2016-01-01

    Objectives: Bone quality and quantity assessment is one of the most important steps in implant treatment planning. Different methods such as computed tomography (CT) and recently suggested cone beam computed tomography (CBCT) with lower radiation dose and less time and cost are used for bone density assessment. This in vitro study aimed to compare the tissue density values in Hounsfield units (HUs) in CBCT and CT scans of different tissue phantoms with two different thicknesses, two different image acquisition settings and in three locations in the phantoms. Materials and Methods: Four different tissue phantoms namely hard tissue, soft tissue, air and water were scanned by three different CBCT and a CT system in two thicknesses (full and half) and two image acquisition settings (high and low kVp and mA). The images were analyzed at three sites (middle, periphery and intermediate) using eFilm software. The difference in density values was analyzed by ANOVA and correction coefficient test (P<0.05). Results: There was a significant difference between density values in CBCT and CT scans in most situations, and CBCT values were not similar to CT values in any of the phantoms in different thicknesses and acquisition parameters or the three different sites. The correction coefficients confirmed the results. Conclusions: CBCT is not reliable for tissue density assessment. The results were not affected by changes in thickness, acquisition parameters or locations. PMID:27928239

  5. Transcranial thermoacoustic tomography: a comparison of two imaging algorithms.

    PubMed

    Liu, Zijian; Liu, Lanbo; Xu, Yuan; Wang, Lihong Victory

    2013-02-01

    Thermoacoustic tomography (TAT) is a novel, non-invasive medical imaging technique but has encountered obstacles in imaging through the cranium. In this paper we present two methods for transcranial TAT: Kirchhoff migration (KM) and reverse-time migration (RTM). The two methods' imaging qualities are verified and compared based on both synthetic and experimental data. RTM proves to have better velocity variance and imaging quality, and little noise with spatial aliasing. RTM is a promising approach for achieving transcranial TAT in further studies.

  6. Training to Use Microcomputers for Accounting Procedures.

    ERIC Educational Resources Information Center

    Halvorsen, Nancy

    1982-01-01

    Discusses microcomputer instruction as an addition to the accounting curriculum and various elements to consider: equipment configuration needed, instructor training, adapting the microcomputer to the classroom, and outcomes of microcomputer use. (CT)

  7. The Microcomputer in the Library: I. Introduction.

    ERIC Educational Resources Information Center

    Leggate, Peter; Dyer, Hilary

    1985-01-01

    This first in a series of six articles introducing microcomputer applications in smaller libraries discusses microcomputer components (hardware, operating systems, applications software); microcomputer history; current hardware; library applications; performance criteria; factors influencing performance; integrated systems; information retrieval;…

  8. Comparison of double crosshole and fanbeam Lamb wave ultrasonic tomography

    NASA Astrophysics Data System (ADS)

    Hinders, Mark K.; Malyarenko, Eugene V.

    2001-04-01

    Ultrasonic guided waves, Lamb waves, allow large sections of aircraft structures to be rapidly inspected. However, extracting quantitative information from Lamb wave data has always involved highly trained personnel with a detailed knowledge of mechanical waveguide physics. The work discussed here focuses on a variety of different tomographic reconstruction techniques to graphically represent the Lamb wave data in quantitative maps that can be easily interpreted by technicians. Because the velocity of Lamb waves depends on thickness, for example, the traveltimes of the fundamental Lamb modes can be converted into a thickness map of the inspection region. This paper describes two potentially practical implementations of Lamb wave tomographic imaging techniques that can be optimized for in-the-field testing of large-area aircraft structures. Laboratory measurements discussed here demonstrate that Lamb wave tomography using either a ring of transducers with fan beam reconstructions, or a square array of transducers with algebraic reconstruction tomography, is appropriate for detecting flaws in multilayer aircraft materials. The speed and fidelity of the reconstruction algorithms as well as practical considerations for person-portable array-based systems are discussed in this presentation.

  9. Role of microcomputed tomography in microvascular imaging

    NASA Astrophysics Data System (ADS)

    Ritman, Erik L.

    2011-03-01

    Micro-CT scans generate three-dimensional images consisting of the order of 10003 voxels (3D picture elements), each cubic voxel being sub-micron to 100 micrometer on a side. The gray-scale modulation within tomographic images reflects the local attenuation of the x-ray. This allows for differentiation of different tissues by virtue of their elemental content. However, the elements in blood vessel walls and within blood differ little from organ parenchyma, hence they are not readily distinguishable unless the attenuation of blood is enhanced by injecting a heavy element (such as iodine) into the blood stream or by staining the vessel wall tissues with heavy metals such as osmium tetroxide. Three-dimensional micro-CT images a volume (of light-opaque tissue) large enough to include entire, intact, vascular trees without the need to destroy the 3D tissue specimen. Hence, the fluid dynamic and the perfusion territory size consequences, as well the micro-anatomic relationship of the vascular branching geometry and interconnectivity to parenchymal structures (e.g., nephron, hepatic lobule or cancer) can be readily appreciated and quantified. The permeability of microvasculature can also be imaged by virtue of the increased contrast resulting from the fraction of the injected contrast agent passing through the endothelium into the surrounding extravascular tissue. In recent years micro-CT based on the imaging of coherent x-ray scatter and on x-ray phase shift caused by local electron density distributions (reflecting molecular bond type in some cases) provide greater inherent image contrast than does x-ray attenuation. These new capabilities are now active avenues of research and development.

  10. TLC for Growing Minds. Microcomputer Projects. Elementary Intermediate Microcomputer Projects.

    ERIC Educational Resources Information Center

    Buxton, Marilyn

    Designed to improve students' thinking, learning, and creative skills while they learn to program a microcomputer in BASIC programing language, this book for intermediate learners at the elementary school level provides a variety of microcomputer activities designed to extend the concepts learned in accompanying instructional manuals (Volumes 3…

  11. Computed tomography and magnetic resonance imaging comparisons in boxers

    SciTech Connect

    Jordan, B.D. ); Zimmerman, R.D. )

    1990-03-23

    The efficacy of computed tomography (CT) and magnetic resonance imaging (MRI) in identifying traumatic injuries of the brain was compared in a referred population of 21 amateur and professional boxers. Three boxers displayed CT scans with equivocal findings that were verified as artifacts by MRI. Eleven boxers had both CT and MRI scans with normal findings, and 7 boxers had both CT and MRI scans with abnormal findings. There were no instances where abnormalities demonstrated on CT scanning were not detected by MRI. However, some abnormalities detected on MRI were not detected on CT scans. These included a subdural hematoma, white-matter changes, and a focal contusion. Magnetic resonance imaging appears to be the neuroradiodiagnostic test of choice compared with CT.

  12. Comparison of gamma-densitometry tomography and electrical-impedance tomography for determining material distribution in liquid-solid flows

    SciTech Connect

    Shollenberger, K.A.; Torczynski, J.R.; O`Hern, T.J.; Adkins, D.R.; Ceccio, S.L.; George, D.L.

    1997-03-01

    The spatial distribution of materials in multiphase flows is of importance to many industrial processes. For example, in indirect coal liquefaction, a reactive gas is bubbled through a catalyst-laden liquid (slurry), and a spatially nonuniform gas distribution can reduce process efficiency by inducing large-scale buoyancy-driven recirculating flows. Gamma-densitometry tomography (GDT) and electrical-impedance tomography (EIT) are techniques with the potential of providing spatially resolved information on material distribution in multiphase flows. GDT and EIT have both been applied to a liquid-solid flow for comparison purposes. The experiment consisted of a cylinder (19 cm diameter) filled with water, in which 80 {micro}m glass spheres were suspended by a mixer to achieve solid volume fractions of 0.01, 0.02, and 0.03. Both GDT and EIT revealed a relatively uniform distribution of solids in the measurement plane, and the average solid volume fractions from both techniques were in good agreement.

  13. Exercise, Health, and the Microcomputer.

    ERIC Educational Resources Information Center

    Felts, W. Michael; And Others

    1983-01-01

    The microcomputer can be an important tool for the health educator faced with the task of designing exercise programs for a variety of individuals in community or worksite settings. The EXERFIT exercise prescription program at the University of Maryland illustrates an application of the microcomputer. (CJ)

  14. Early Childhood Education and Microcomputers.

    ERIC Educational Resources Information Center

    Lee, Marjorie W.

    Soon families of every socioeconomic level will have microcomputers in their homes. Most classrooms and probably all schools will have at least one such machine. Many potential advantages may result from the involvement of young children with microcomputers. Some of these are the stimulation of reflective thinking, the development of cognitive…

  15. Microcomputer Competencies for Vocational Teachers.

    ERIC Educational Resources Information Center

    Roth, Gene L.; Tesolowski, Dennis G.

    1984-01-01

    This joint research and development project of two state departments of education used the DACUM (Developing a Curriculum) process to identify microcomputer competencies for vocational instructors. Brainstorming techniques were used to identify five categories of microcomputer applications and to determine which competencies belonged in each…

  16. Chips and Diodes of Microcomputers.

    ERIC Educational Resources Information Center

    Sherbon, James W.

    1983-01-01

    Common computer terminology, microcomputer systems, peripheral equipment, and internal workings are discussed. Factors affecting establishment of a microcomputer in a music department are objectives and needs, available or easily created software, and hardware configurations that fit budgets yet provide needed power and flexibility. (KC)

  17. Microcomputers in the Media Center.

    ERIC Educational Resources Information Center

    Sherouse, Vicki, Ed.; Post, Richard, Ed.

    Produced to provide educators and library media personnel with some understanding of and direction in the rapidly expanding field of microcomputers and their applications, this monograph includes several articles dealing specifically with media center applications and others concerned more generally with the microcomputer in educational settings.…

  18. Microcomputer Software for Vocational Education.

    ERIC Educational Resources Information Center

    Levy, Laurie, Comp.

    This listing offers educators a resource for locating microcomputer software to meet the specific needs of their vocational programs and students. Approximately 650 separate items of microcomputer software for vocational education programs are included. The software is categorized under 10 skill areas: agriculture, business, careers, computer…

  19. Trends In Microcomputer Image Processing

    NASA Astrophysics Data System (ADS)

    Strum, William E.

    1988-05-01

    We have seen, in the last four years, the microcomputer become the platform of choice for many image processing applications. By 1991, Frost and Sullivan forecasts that 75% of all image processing will be carried out on microcomputers. Many factors have contributed to this trend and will be discussed in the following paper.

  20. Microcomputers: Applications in Vocational Education.

    ERIC Educational Resources Information Center

    Rodenstein, Judith, Ed.; Lambert, Roger, Ed.

    This handbook was assembled for vocational educators so that they can see the applications of microcomputers in both their instructional and administrative tasks. The 22 papers included in the handbook were written by educators who are and have been using microcomputers extensively in their work. The first section of the handbook discusses the…

  1. Authority Files for Microcomputer Databases.

    ERIC Educational Resources Information Center

    Brandt, Scott

    1988-01-01

    Examines the function of an authority file and the application of authority control to microcomputer-based library databases. Capabilities of relational database management systems which allow for an authority control system on the microcomputer level are noted. (10 references) (MES)

  2. A General Introduction to Microcomputers.

    ERIC Educational Resources Information Center

    Muiznieks, Viktors

    This basic introduction to microcomputers provides the neophyte with the terminology, definitions, and concepts that explain the microcomputer and computing technology in general. Mathematical operations with binary numbers, computer storage, controlling logic, and the concepts of stack and interrupt are explained. (RAO)

  3. Microcomputer Use in Collection Development.

    ERIC Educational Resources Information Center

    Welsch, Erwin K.; And Others

    1985-01-01

    Describes different applications of microcomputers for acquisitions and collection development in three of the university libraries at the University of Wisconsin-Madison. Highlights include differences in hardware and software for similar tasks, utilization problems, generalizations about strategies for effective microcomputer use in collection…

  4. A comparison of computed tomography practice in 1989 and 1991.

    PubMed

    Crawley, M T; Rogers, A T

    1994-09-01

    In December 1991, the National Radiological Protection Board (NRPB) published the results of national surveys of the frequency, quality assurance and dosimetric aspects of computed tomography (CT) examinations carried out in hospitals in the UK in 1989. A study of the patient records at two of the original participating hospitals was undertaken to establish whether there had been any change in CT practice between the years 1989 and 1991. Aspects of examination frequency, age distribution and dose were analysed. The results showed significant variations in the patient age distributions between the sub-population studied and the larger sample used by the NRPB, and between the patient age distribution for CT examinations in the years 1989 and 1991 at the two hospitals in this study. The results also showed that in one hospital, where magnetic resonance imaging (MRI) was available and where dose reduction measures had been implemented, there was a net decrease in the collective effective dose from 1989 to 1991, whilst at the other hospital, where MRI was not available and where the introduction of dose saving strategies had been delayed, there was a substantial increase in the collective effective dose from 1989 to 1991. The possibility of continuing increases in the annual collective effective dose attributable to CT underlines the importance of local CT audit to ensure that CT doses are as low as reasonably achievable.

  5. Solitary pulmonary metastases in high-risk melanoma patients: a prospective comparison of conventional and computed tomography

    SciTech Connect

    Heaston, D.K.; Putman, C.E.; Rodan, B.A.; Nicholson, E.; Ravin, C.E.; Korobkin, M.; Chen, J.T.; Seigler, H.F.

    1983-07-01

    A prospective comparison of chest radiography, conventional tomography, and computed tomography (CT) in the detection or confirmation of solitary pulmonary nodules was made in 42 patients with high propensity for pulmonary metastases due to advanced local (Clark level IV or V) or regional malignant melanoma. Unequivocal nodules were revealed by chest radiography in 11 patients, conventional tomograhy in 16, and computed tomography in 20 patients. Both plain films and tomography in three of these 20 were normal, but follow-up verified pulmonary metastases. Computed tomography detected more pulmonary nodules than conventional tomography in 11 patients in addition to identifying lesions in extrapulmonary sites. Therefore, chest CT is recommended before institution of immunotherapy or surgical removal of a solitary pulmonary melanoma metastasis. Once chemotherapy had been instituted for bulky regional or cutaneous involvement, however, the findings of either conventional or computed tomography were comparable in this study.

  6. Bone comparison identification method based on chest computed tomography imaging.

    PubMed

    Matsunobu, Yusuke; Morishita, Junji; Usumoto, Yosuke; Okumura, Miki; Ikeda, Noriaki

    2017-08-31

    The aim of this study is to examine the usefulness of bone structure extracted data from chest computed tomography (CT) images for personal identification. Eighteen autopsied cases (12 male and 6 female) that had ante- and post-mortem (AM and PM) CT images were used in this study. The two-dimensional (2D) and three-dimensional (3D) bone images were extracted from the chest CT images via thresholding technique. The similarity between two thoracic bone images (consisting of vertebrae, ribs, and sternum) acquired from AMCT and PMCT images was calculated in terms of the normalized cross-correlation value (NCCV) in both 2D and 3D matchings. An AM case with the highest NCCV corresponding to a given PM case among all of the AM cases studied was regarded as same person. The accuracy of identification of the same person using our method was 100% (18/18) in both 2D and 3D matchings. The NCCVs for the same person tended to be significantly higher than the average of NCCVs for different people in both 2D and 3D matchings. The computation times of image similarity between the two images were less than one second and approximately 10min in 2D and 3D matching, respectively. Therefore, 2D matching especially for thoracic bones seems more advantageous than 3D matching with regard to computation time. We conclude that our proposed personal identification method using bone structure would be useful in forensic cases. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Comparison of denture models by means of micro computed tomography

    NASA Astrophysics Data System (ADS)

    Vögtlin, Christoph; Schulz, Georg; Deyhle, Hans; Jäger, Kurt; Liebrich, Thomas; Weikert, Sascha; Müller, Bert

    2012-10-01

    The production of dental inlays and crowns requires precise information on patients' teeth morphology. The conventional method is the preparation of impressions using mold materials, e.g. a silicone impression material. The disadvantage of this technique is the human choke impulse and the flavor of the material. These discomforts can be avoided by methods where a three-dimensional scanner is used for recording the teeth morphology. The present study reveals the accuracy of three model types, namely conventional impression, rapid prototyping using an oral scanner C.O.S., 3M (Schweiz) AG and milling from a proprietary resin using the oral scanner iTero, Straumann Holding AG. For each method five models were fabricated from a steel reference (standard). Using a nanotom m (phoenixǀx-ray, GE Sensing and Inspection Technologies GmbH), three-dimensional micro computed tomography data sets of the standard and the 15 models were recorded and landmark distances within the data sets were measured with sub-pixel accuracy. To verify these results a coordinate measuring machine (Leitz PMM 864, Hexagon Metrology GmbH) based on tactile detection was used for the measurement of the landmark distances, and a correction of the distances measured by the nanotom m was arranged. The nanotom data sets of the 15 models were also compared to the standard by means of a non-rigid registration algorithm. The calculated deformation field exhibited mean pixel displacement values of (0.19 +/- 0.09) mm for the C.O.S. models, (0.12 +/- 0.07) mm for the gypsum models and (0.19 +/- 0.12) mm for the i-Tero models.

  8. Comparison of computed tomography scout based reference point localization to conventional film and axial computed tomography.

    PubMed

    Jiang, Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C H

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  9. The Impact of Microcomputers on Rural Schools.

    ERIC Educational Resources Information Center

    Smith, Frank A.

    This review of articles and facts about microcomputers focuses on the development of hardware and software and the use of microcomputers in education, particularly rural education. In addition to presenting a brief history of microcomputers, the review presents information regarding the costs and brands of microcomputers; the development, use,…

  10. On Some Applications of Microcomputers in Teleinformatics,

    DTIC Science & Technology

    1983-03-02

    called *: microcomputers. The present article is an attempt to outline the place and role of : microprocessors and microcomputers n teleinformatics...for this situation is that the current applications of telecomunications for voice and digital data transmission are in constant develop- sent, which... article will be devoted exclusively to microcomputers used in teleinformatics equipment, systems and networks. The Place of Microcomputers in

  11. Microcomputer versus mainframe simulations: A case study

    NASA Technical Reports Server (NTRS)

    Bengtson, Neal M.

    1988-01-01

    The research was conducted to two parts. Part one consisted of a study of the feasibility of running the Space Transportation Model simulation on an office IBM-AT. The second part was to design simulation runs so as to study the effects of certain performance factors on the execution of the simulation model. The results of this research are given in the two reports which follow: Microcomputer vs. Mainframe Simulation: A Case Study and Fractional Factorial Designs of Simulation Runs for the Space Transportation System Operations Model. In the first part, a DOS batch job was written in order to simplify the execution of the simulation model on an office microcomputer. A comparison study was then performed of running the model on NASA-Langley's mainframe computer vs. running on the IBM-AT microcomputer. This was done in order to find the advantages and disadvantages of running the model on each machine with the objective of determining if running of the office PC was practical. The study concluded that it was. The large number of performance parameters in the Space Transportation model precluded running a full factorial design needed to determine the most significant design factors. The second report gives several suggested fractional factorial designs which require far fewer simulation runs in order to determine which factors have significant influence on results.

  12. Quantitative comparison of analysis methods for spectroscopic optical coherence tomography: reply to comment

    PubMed Central

    Bosschaart, Nienke; van Leeuwen, Ton G.; Aalders, Maurice C.G.; Faber, Dirk J.

    2014-01-01

    We reply to the comment by Kraszewski et al on “Quantitative comparison of analysis methods for spectroscopic optical coherence tomography.” We present additional simulations evaluating the proposed window function. We conclude that our simulations show good qualitative agreement with the results of Kraszewski, in support of their conclusion that SOCT optimization should include window shape, next to choice of window size and analysis algorithm. PMID:25401016

  13. (18)F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma.

    PubMed

    Li, Xiao-Feng; Fu, Qiang; Dong, You-Wen; Liu, Jian-Jing; Song, Xiu-Yu; Dai, Dong; Zuo, Cong; Xu, Wen-Gui

    2016-09-14

    To compare (18)F-fluorodeoxyglucose positron emission tomography/computed tomography ((18)F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma. Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent (18)F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ(2) test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone. PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma.

  14. 18F-fluorodeoxyglucose positron emission tomography/computed tomography comparison of gastric lymphoma and gastric carcinoma

    PubMed Central

    Li, Xiao-Feng; Fu, Qiang; Dong, You-Wen; Liu, Jian-Jing; Song, Xiu-Yu; Dai, Dong; Zuo, Cong; Xu, Wen-Gui

    2016-01-01

    AIM To compare 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) features in gastric lymphoma and gastric carcinoma. METHODS Patients with newly diagnosed gastric lymphoma or gastric carcinoma who underwent 18F-FDG PET/CT prior to treatment were included in this study. We reviewed and analyzed the PET/CT features of gastric wall lesions, including FDG avidity, pattern (focal/diffuse), and intensity [maximal standard uptake value: (SUVmax)]. The correlation of SUVmax with gastric clinicopathological variables was investigated by χ2 test, and receiver-operating characteristic (ROC) curve analysis was performed to determine the differential diagnostic value of SUVmax-associated parameters in gastric lymphoma and gastric carcinoma. RESULTS Fifty-two patients with gastric lymphoma and 73 with gastric carcinoma were included in this study. Abnormal gastric FDG accumulation was found in 49 patients (94.23%) with gastric lymphoma and 65 patients (89.04%) with gastric carcinoma. Gastric lymphoma patients predominantly presented with type I and type II lesions, whereas gastric carcinoma patients mainly had type III lesions. The SUVmax (13.39 ± 9.24 vs 8.35 ± 5.80, P < 0.001) and SUVmax/THKmax (maximal thickness) (7.96 ± 4.02 vs 4.88 ± 3.32, P < 0.001) were both higher in patients with gastric lymphoma compared with gastric carcinoma. ROC curve analysis suggested a better performance of SUVmax/THKmax in the evaluation of gastric lesions between gastric lymphoma and gastric carcinoma in comparison with that of SUVmax alone. CONCLUSION PET/CT features differ between gastric lymphoma and carcinoma, which can improve PET/CT evaluation of gastric wall lesions and help differentiate gastric lymphoma from gastric carcinoma. PMID:27678362

  15. Interfacing Microcomputers with Laboratory Instruments.

    ERIC Educational Resources Information Center

    Long, Joseph W.

    1983-01-01

    Describes development of microcomputer-controlled gamma scintillation spectrometer and chromatographic data analyzer, including design and construction of interface electronics and production of software. Includes diagrams of electric circuits and project evaluation indicating that both instruments functioned as intended. (JN)

  16. Using Microcomputers for Institutional Research.

    ERIC Educational Resources Information Center

    Suttle, J. Lloyd

    1984-01-01

    Many institutional researchers will find that the microcomputer leads to greater efficiency in everything that they do, especially in the two most critical elements of their jobs: thinking and communicating. (Author/MLW)

  17. Simple Interval Timers for Microcomputers.

    ERIC Educational Resources Information Center

    McInerney, M.; Burgess, G.

    1985-01-01

    Discusses simple interval timers for microcomputers, including (1) the Jiffy clock; (2) CPU count timers; (3) screen count timers; (4) light pen timers; and (5) chip timers. Also examines some of the general characteristics of all types of timers. (JN)

  18. Microcomputer Systems for Medical Researchers

    PubMed Central

    Bassler, Richard A.

    1982-01-01

    A bewildering array of choices awaits the medical researchers in the selection of microcomputer systems. These are real computers capable of producing real products. Choosing one is difficult. Software is the starting point. Inexpensive computing is possible for everyone.

  19. Learner/User Preferences for Fonts in Microcomputer Screen Displays.

    ERIC Educational Resources Information Center

    Misanchuk, Earl R.

    1989-01-01

    Describes study that was conducted with 62 subjects who varied in age, educational background, and computer experience, to determine user preferences for fonts on a Macintosh microcomputer screen display. Topics discussed include the forced choice comparison mode used, a HyperCard stack designed for the study, and a Thurstone scale derived from…

  20. Microcomputer stratigraphic applications

    SciTech Connect

    Choyce, R.

    1984-04-01

    With the advent of large-capacity computer files, interactive languages for retrieval of large data bases, and low-cost effective microcomputers, the approach to stratigraphic analysis has been dramatically improved. In terms of immediate payoff, the computer assumes the role of retriever and data presenter, while the geologist concentrates on analysis of retrieved data. The biggest benefit of these new approaches is a measurable increase in productivity for the geologist. Through use of the computer, gathering and interpretive data from sample logs are greatly facilitated. With the computer, logs are encoded electronically for access by the geologist via a computer terminal, and analysis of the data is accomplished interactively. The process obviates the need for the time-consuming process of locating the appropriate logs, hanging them for analysis, and researching each log to locate appropriate intervals for correlation and interpretation. Recent studies indicate that through computerized approaches, time required for these steps is vastly diminished, and resulting productivity is 40-80% greater than with conventional manual methods. A by-product of this approach results from the data being created in a form that lends itself to graphic presentation upon demand by the geologist. This avoids the time-consuming delays inherent in interrelating with the computing department for mapping requests to ensure that the results of the analysis are as expected. With the computer, many kinds of maps become practical to produce from the terminal, including base maps, cross sections, and lithofacies, structures, and isopach maps.

  1. Microcomputer processing for Loran-C

    NASA Technical Reports Server (NTRS)

    Lilley, R. W.; Mccall, D. L.; Novacki, S. M., III

    1981-01-01

    Schematic diagrams are presented for the microcomputer processing for Loran-C. Diagrams are included for the following: microcomputer Loran-C loop improvements; Loran-C receiver commutated AGC; and DC-DC power supply.

  2. Idaho State University Bookstore Features Microcomputer Fair.

    ERIC Educational Resources Information Center

    Ogg, Robert; Hill, Leland R.

    1983-01-01

    A microcomputer fair held during homecoming and in conjunction with the opening of the ISU Microcomputer Learning Facility resulted in an unprecedented explosion of interest and buying. The store was also selling computer books, supplies, and software. (Author/MLW)

  3. Microcomputers: Tools of the Present and Future.

    ERIC Educational Resources Information Center

    Lopez, Antonio M., Jr.

    1981-01-01

    Identifies commercially available microcomputer systems, briefly reviews the use of microcomputers in education, describes uses of computers in the home, and sketches the role of computers in libraries. Seven references are cited. (FM)

  4. Diagnosis of simulated condylar bone defects using panoramic radiography, spiral tomography and cone-beam computed tomography: A comparison study

    PubMed Central

    Salemi, Fatemeh; Shokri, Abbas; Baharvand, Maryam

    2015-01-01

    Objectives: Radiographic examination is one of the most important parts of the clinical assessment routine for temporomandibular disorders. The aim of this study was to compare the diagnostic accuracy of cone-beam computed tomography(CBCT) with panoramic radiography and spiral computed tomography for the detection of the simulated mandibular condyle bone lesions. Study Design: The sample consisted of 10 TMJs from 5 dried human skulls. Simulated erosive and osteophytic lesions were created in 3 different sizes using round diamond bur and bone chips, respectively. Panoramic radiography, spiral tomography and cone-beam computed tomography were used in defect detection. Data were statistically analyzed with the Mann-Whitney test. The reliability and degrees of agreement between two observers were also determined by the mean of Cohen’s Kappa analysis. Results: CBCT had a statistically significant superiority than other studied techniques in detection of both erosive and osteophytic lesions with different sizes. There were significant differences between tomography and panoramic in correct detection of both erosive and osteophytic lesions with 1mm and 1.5 mm in size. However, there were no significant differences between Tomography and Panoramic in correct detection of both erosive and osteophytic lesions with 0.5 mm in size. Conclusions: CBCT images provide a greater diagnostic accuracy than spiral tomography and panoramic radiography in the detection of condylar bone erosions and osteophytes. Key words:Bone defect, Condyle, CBCT, Panoramic, radiography. PMID:25810839

  5. Statistical Software Packages for the Microcomputer.

    ERIC Educational Resources Information Center

    Finley, Sevilla, Comp.

    The nine microcomputer statistical software packages that are described comprise the statistical software collection at the Appalachia Educational Laboratory (AEL). The packages are compatible with AEL's Apple II microcomputer, though many are also available with other microcomputers. References to software reviews are included for some programs.…

  6. Library Microcomputers: Some Notes Gained from Experience.

    ERIC Educational Resources Information Center

    Fosdick, Howard

    1984-01-01

    Responses to librarians' questions about library microcomputers cover simple applications to be used by staff with little experience, minimizing risk factor, choosing a microcomputer, hardware obsolescence, uses of mainframes and minicomputers, capacity planning for microcomputers, security of library's data, copyrighted software, and future use…

  7. Accessing ERIC with Your Microcomputer. ERIC Digest.

    ERIC Educational Resources Information Center

    Klausmeier, Jane A.

    Focusing on how to use a microcomputer as a terminal for searching online databases, this digest addresses the following topics: (1) hardware and software requirements; (2) configuring the software; and (3) basic requirements for specific microcomputers. Special features in communications software which allow microcomputer users to do database…

  8. Microcomputer Use in Illinois Vocational Agriculture Programs.

    ERIC Educational Resources Information Center

    Henderson, Janet L.

    1985-01-01

    A study was conducted to assess the current status of microcomputer use by vocational agriculture instructors in Illinois. The study identified the number and types of microcomputers currently being used by vocational agriculture instructors, determined the techniques for managing microcomputer use, and identified the types of software currently…

  9. Satellite Doppler data processing using a microcomputer

    NASA Technical Reports Server (NTRS)

    Schmid, P. E.; Lynn, J. J.

    1977-01-01

    A microcomputer which was developed to compute ground radio beacon position locations using satellite measurements of Doppler frequency shift is described. Both the computational algorithms and the microcomputer hardware incorporating these algorithms were discussed. Results are presented where the microcomputer in conjunction with the NIMBUS-6 random access measurement system provides real time calculation of beacon latitude and longitude.

  10. Microcomputer Support in Basic Statistics Instruction.

    ERIC Educational Resources Information Center

    Schafer, William D; Johnson, Charles E.

    This paper presents examples of effective uses of microcomputers to support basic statistics instruction. All programs are written in Applesoft BASIC for Apple II Plus microcomputers and compatible equipment. They have been field tested in statistics courses at the University of Maryland. Microcomputers can be used with color monitors for…

  11. Microcomputer Data Base Programs in Social Research.

    ERIC Educational Resources Information Center

    Tate, C. Neal

    1986-01-01

    Microcomputer uses by social researchers include writing programs, standard spreadsheets and data base management. In addition, microcomputers can increase the effectiveness and efficiency of information gathering by improving notetaking and organizing. Software developments will help make microcomputer data base management tools, now not…

  12. Comparison of approaches based on optimization and algebraic iteration for binary tomography

    NASA Astrophysics Data System (ADS)

    Cai, Weiwei; Ma, Lin

    2010-12-01

    Binary tomography represents a special category of tomographic problems, in which only two values are possible for the sought image pixels. The binary nature of the problems can potentially lead to a significant reduction in the number of view angles required for a satisfactory reconstruction, thusly enabling many interesting applications. However, the limited view angles result in a severely underdetermined system of equations, which is challenging to solve. Various approaches have been proposed to address such a challenge, and two categories of approaches include those based on optimization and those based on algebraic iteration. However, the relative strengths, limitations, and applicable ranges of these approaches have not been clearly defined in the past. Therefore, it is the main objective of this work to conduct a systematic comparison of approaches from each category. This comparison suggested that the approaches based on algebraic iteration offered both superior reconstruction fidelity and computation efficiency at low (two or three) view angles, and these advantages diminished at high view angles. Meanwhile, this work also investigated the application of regularization techniques, the selection of optimal regularization parameter, and the use of a local search technique for binary problems. We expect the results and conclusions reported in this work to provide valuable guidance for the design and development of algorithms for binary tomography problems.

  13. Microcomputer Business Applications. Teacher Edition.

    ERIC Educational Resources Information Center

    James, Marcia; And Others

    This curriculum guide is designed to teach concepts associated with business applications of microcomputers. It can be used in marketing, office education, and computer literacy courses. Most activities can be done in less than 1 hour. The course is organized in eight units that cover the following: (1) systems and software; (2) electronic filing;…

  14. Networking and Microcomputers. ERIC Digest.

    ERIC Educational Resources Information Center

    Klausmeier, Jane

    Computer networks can fall into three broad categories--local area networks (LAN), microcomputer based messaging systems (this includes computer bulletin board systems), or commercial information systems. Many of the same types of activities take place within the three categories. The major differences are the types of information available and…

  15. Microcomputer Application in Industrial Education.

    ERIC Educational Resources Information Center

    Matthews, John I.

    1980-01-01

    A microcomputer for use in industrial education programs is described. The system has wide application and does not require programing skills. Graduate students may purchase disks formatted to do word processing and statistics then proceed to do the thesis or dissertation final copy at the keyboard of the terminal. (CT)

  16. Microcomputer Hardware. Energy Technology Series.

    ERIC Educational Resources Information Center

    Technical Education Research Centre-Southwest, Waco, TX.

    This course in microcomputer hardware is one of 16 courses in the Energy Technology Series developed for an Energy Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in company-sponsored…

  17. Microcomputer Modules for Undergraduate Geography.

    ERIC Educational Resources Information Center

    Groop, Richard; And Others

    1985-01-01

    Described and evaluated are microcomputer units of instruction that were developed for use in undergraduate geography courses. Students responded favorably to the modules--"Socioeconomic Patterns,""Economic Rent,""Sampling Distribution of Sample Means,""Land Use Competition,""Data Classing,""Weather and Climate," and "Landforms." (RM)

  18. Software design methodologies for microcomputers

    NASA Astrophysics Data System (ADS)

    Dowsing, R. D.

    1982-05-01

    It is the development phase of the software lifecycle which has attracted a great deal of interest in the last few years. This paper surveys the stages in software production and the need for a rigorous, formal approach. This type of approach is illustrated by the development of a program for a microcomputer using structured programming techniques.

  19. Microcomputers for Laboratory Data Collection.

    ERIC Educational Resources Information Center

    McMillen, Jack D.; Esch, Harald E.

    1984-01-01

    Advantages of computerized data acquisition and three approaches to data collection are discussed. Interfacing techniques and use of microcomputers as physiological recorders are also discussed. Examples of computerized data acquisition are provided. These include computer monitoring of animal activity and collecting data from species distribution…

  20. Microcomputer Operations. Energy Technology Series.

    ERIC Educational Resources Information Center

    Center for Occupational Research and Development, Inc., Waco, TX.

    This course in microcomputer operations is one of 16 courses in the Energy Technology Series developed for an Energy Conservation-and-Use Technology curriculum. Intended for use in two-year postsecondary technical institutions to prepare technicians for employment, the courses are also useful in industry for updating employees in company-sponsored…

  1. Microcomputers and the Department Image.

    ERIC Educational Resources Information Center

    Donaghy, William C.; Donaghy, Carole D.

    Ways in which various uses or applications of a microcomputer can help improve the image of a college or university department are discussed in this paper. The paper discusses applications such as instruction, word processing, management, programing, communications, statistics, and graphics, and audiences for these applications, such as department…

  2. Assessing Functional Vision Using Microcomputers.

    ERIC Educational Resources Information Center

    Spencer, Simon; Ross, Malcolm

    1989-01-01

    The paper describes a software system which uses microcomputers to aid in the assessment of functional vision in visually impaired students. The software also aims to be visually stimulating and to develop hand-eye coordination, visual memory, and cognitive abilities. (DB)

  3. The Microcomputer and School Transportation.

    ERIC Educational Resources Information Center

    Dembowski, Frederick L.

    1984-01-01

    Microcomputers have many cost- and time-saving uses in school transportation management. Applications include routing and scheduling, demographic analysis, fleet maintenance, and personnel and contract management. Word processing is especially promising for storing and updating documents like specifications. Enrollment forecasting and inventory…

  4. History Microcomputer Games: Update 2.

    ERIC Educational Resources Information Center

    Sargent, James E.

    1985-01-01

    Provides full narrative reviews of B-1 Nuclear Bomber (Avalon, 1982); American History Adventure (Social Science Microcomputer Review Software, 1985); Government Simulations (Prentice-Hall, 1985); and The Great War, FDR and the New Deal, and Hitler's War, all from New Worlds Software, 1985. Lists additional information on five other history and…

  5. Microcomputer Business Applications. Teacher Edition.

    ERIC Educational Resources Information Center

    James, Marcia; And Others

    This curriculum guide is designed to teach concepts associated with business applications of microcomputers. It can be used in marketing, office education, and computer literacy courses. Most activities can be done in less than 1 hour. The course is organized in eight units that cover the following: (1) systems and software; (2) electronic filing;…

  6. History Microcomputer Simulations: An Update.

    ERIC Educational Resources Information Center

    Sargent, James E.

    1985-01-01

    This article summarizes seven currently available microcomputer simulations for history. The seven included are: Government Simulations (Prentice-Hall, 1984), Nomination (Brady Company, 1984), Tigers in the Snow (Strategic Simulations, 1981), Lincoln's Decisions (Educational Activities, 1982), Watergate Simulation (Social Science Research and…

  7. History Microcomputer Simulations: An Update.

    ERIC Educational Resources Information Center

    Sargent, James E.

    1985-01-01

    This article summarizes seven currently available microcomputer simulations for history. The seven included are: Government Simulations (Prentice-Hall, 1984), Nomination (Brady Company, 1984), Tigers in the Snow (Strategic Simulations, 1981), Lincoln's Decisions (Educational Activities, 1982), Watergate Simulation (Social Science Research and…

  8. Microcomputer Series. Duty Task List.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the occupational duty/task lists for eight occupations in the microcomputer series. Each occupation is divided into 5 to 11 duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide space…

  9. Microcomputer Series. Duty Task List.

    ERIC Educational Resources Information Center

    Oklahoma State Dept. of Vocational and Technical Education, Stillwater. Curriculum and Instructional Materials Center.

    This document contains the occupational duty/task lists for eight occupations in the microcomputer series. Each occupation is divided into 5 to 11 duties. A separate page for each duty in the occupation lists the tasks in that duty along with its code number and columns to indicate whether that particular duty has been taught and to provide space…

  10. Special-Interest Microcomputing Publications.

    ERIC Educational Resources Information Center

    Colsher, William L.

    1980-01-01

    This article describes computer journals, newsletters, and cassette magazines that are devoted to a particular brand of personal computer, such as the TRS-80, or to a particular microprocessor, such as the 6502, used in the Apple II, Commodore PET, and other microcomputers. Publishers' addresses and rates are listed. (Author/SJL)

  11. Administrative Uses of the Microcomputer.

    ERIC Educational Resources Information Center

    Spuck, Dennis W.; Atkinson, Gene

    1983-01-01

    An outline of microcomputer applications for administrative computing in education is followed by discussions of aspects of office automation, database management systems, management information systems, administrative computer systems, and software. Several potential problems relating to administrative computing in education are identified.…

  12. Microcomputer Applications in Interaction Analysis.

    ERIC Educational Resources Information Center

    Wadham, Rex A.

    The Timed Interval Categorical Observation Recorder (TICOR), a portable, battery powered microcomputer designed to automate the collection of sequential and simultaneous behavioral observations and their associated durations, was developed to overcome problems in gathering subtle interaction analysis data characterized by sequential flow of…

  13. Microcomputer Infusion Project: A Model.

    ERIC Educational Resources Information Center

    Rossberg, Stephen A.; Bitter, Gary G.

    1988-01-01

    Describes the Microcomputer Infusion Project (MIP), which was developed at Arizona State University to provide faculty with the necessary hardware, software, and training to become models of computer use in both lesson development and presentation for preservice teacher education students. Topics discussed include word processing; database…

  14. History Microcomputer Games: Update 2.

    ERIC Educational Resources Information Center

    Sargent, James E.

    1985-01-01

    Provides full narrative reviews of B-1 Nuclear Bomber (Avalon, 1982); American History Adventure (Social Science Microcomputer Review Software, 1985); Government Simulations (Prentice-Hall, 1985); and The Great War, FDR and the New Deal, and Hitler's War, all from New Worlds Software, 1985. Lists additional information on five other history and…

  15. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography

    PubMed Central

    Konecky, Soren D.; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M.; Saffer, Janet R.; Freifelder, Richard; Karp, Joel S.; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G.

    2008-01-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions. PMID:18383664

  16. Comparison of diffuse optical tomography of human breast with whole-body and breast-only positron emission tomography.

    PubMed

    Konecky, Soren D; Choe, Regine; Corlu, Alper; Lee, Kijoon; Wiener, Rony; Srinivas, Shyam M; Saffer, Janet R; Freifelder, Richard; Karp, Joel S; Hajjioui, Nassim; Azar, Fred; Yodh, Arjun G

    2008-02-01

    We acquire and compare three-dimensional tomographic breast images of three females with suspicious masses using diffuse optical tomography (DOT) and positron emission tomography (PET). Co-registration of DOT and PET images was facilitated by a mutual information maximization algorithm. We also compared DOT and whole-body PET images of 14 patients with breast abnormalities. Positive correlations were found between total hemoglobin concentration and tissue scattering measured by DOT, and fluorodeoxyglucose (18F-FDG) uptake. In light of these observations, we suggest potential benefits of combining both PET and DOT for characterization of breast lesions.

  17. Computed tomography for the detection of thumb base osteoarthritis: comparison with digital radiography.

    PubMed

    Saltzherr, Michael S; van Neck, Johan W; Muradin, Galied S R; Ouwendijk, Rody; Luime, Jolanda J; Coert, J Henk; Hovius, Steven E R; Selles, Ruud W

    2013-05-01

    To compare computed tomography (CT) with digital radiography for the detection of osteoarthritis (OA) of the first carpometacarpal (CMC1) and scaphotrapeziotrapezoid (STT) joint. We retrospectively identified patients who were assessed for CMC1 OA or STT OA at our hand surgery outpatient clinic between January 2008 and March 2011, and who had both a digital radiograph and a CT scan of the hand within a 3-month period. CT and radiographic images were scored independently by two musculoskeletal radiologists for joint space narrowing (JSN), osteophytes, subchondral sclerosis, bone cysts, and erosions in the CMC1 and STT joints. Thirty patients were identified. The inter-reader reliability of CT for the detection of CMC1 OA (ICC 1.00) and STT OA (ICC 0.80) was higher than radiography (ICC's 0.15 and 0.45). In comparison with their own radiographical scoring, both readers detected with CT 3 more patients with CMC1 OA, and 13 and 5 more patients with STT OA. Computed tomography had a higher inter-reader reliability and detection rate for both CMC1 and STT OA, compared with radiography. As surgical treatment selection of thumb base OA depends on the presence of pathology in the CMC1 and STT joints, CT may improve treatment selection and surgical planning.

  18. MST-80B microcomputer trainer

    SciTech Connect

    Jones, G.D.; Fisher, E.R.; Spann, J.M.

    1980-04-01

    The microcomputer revolution in electronics is spreading so rapidly that it is difficult to educate enough people quickly and thoroughly in the new technology. Lawrence Livermore Laboratory's MST-80B was developed as a way to speed learning in in-house training courses, and it is now being widely used outside LLL. The MST-80B trainer is a complete, self-contained, microcomputer system housed in a briefcase. The trainer uses the Intel 8080A 8-Bit Microprocessor (CPU), and it has its own solid-state memory, a built-in keyboard, input and output ports, and a display for visual output. The trainer is furnished with a permanent Monitor Program (in Read-Only Memory) that allows users to enter, debug, modify, and run programs of their own easily. 8 figures, 3 tables.

  19. Microcomputers and the Electrical Engineer.

    DTIC Science & Technology

    1984-07-01

    MicroPro personnel will verify number of computers per training site and may conduct audits at any time . Licenses cannot be granted to organizations...Chapter 1 Legalities of Software Duplication Any discussion of microcomputers will, sooner or later, lead to the topic of whether or...It is important that these discussions are based on fact and that legal agreements have been made with manufacturers of software before any

  20. Universal Disk Controller for Microcomputers.

    DTIC Science & Technology

    1983-12-01

    The research accomplished for this project was not aimed at solving the entire problem, but was focussed on an area which was manageable, and most...CP/M files. CP/M is an operating system for CI microcomputers produced by Digital Research . There are versions of CP/M for a wide variety of...its own disk controller for its domestic file activities. Orer-o Presentation Thefolowig captrsdiscuss the research , design, and implementation of the

  1. Comparison of optoacoustic tomography with ultrasound and x-ray imaging for breast cancer detection

    NASA Astrophysics Data System (ADS)

    Larin, Kirill V.; Hartrumpf, O.; Larina, Irina V.; Esenaliev, Rinat O.

    2001-06-01

    This paper is devoted to comparison new optoacoustic tomography with conventional breast tumors diagnostic techniques such as ultrasonography and X-ray radiography. Experiments were performed in phantoms simulating breast with tumors. The fundamental harmonic of Q-switched Nd:YAG laser (λ = 1064 nm) was used to generate optoacoustic pressure waves. Laser induced pressure waves were detected by a wide-band acoustic transducer. Digital oscilloscope controlled by PC was used to store and process optoacoustic signals. Gelatin phantoms with controlled optical parameters were prepared to simulate breast with tumors. Absorbing volumes colored with naphthol green and hemoglobin were embedded in the gelatin phantoms to model the breast tumors with increased optical absorption. Optoacoustic pressure waves form the phantoms were detected at different angles and 2D images were reconstructed. Comparison of optoacoustic images with images obtained with ultrasound and X-ray techniques proved that optoacoustic method has substantially higher contrast and resolution. Obtained results confirm that laser optoacoustic imaging technique can be an important tool for early breast cancer detection with tumors less than 5 mm in diameter.

  2. Comparison of computed tomography dose index in polymethyl methacrylate and nylon dosimetry phantoms

    PubMed Central

    Sookpeng, Supawitoo; Cheebsumon, Patsuree; Pengpan, Thanyawee; Martin, Colin

    2016-01-01

    The use of computed tomography (CT) scanning has been growing steadily. Therefore, CT dose measurement is becoming increasingly important for patient protection and optimization. A phantom is an important tool for dose measurement. This paper focuses on the evaluation of a CT dosimetry phantom made from nylon, instead of the standard polymethyl methacrylate (PMMA), which is not readily available or is too expensive in some countries. Comparison between phantoms made from the two materials is made in terms of measurements of the CT dose indices (CTDI). These were measured for four different beam widths and kVp settings at the center and periphery in head and body phantoms made from both materials and weighted CTDIs (CTDIw) were calculated. CT numbers along the z-axis of the phantom were also measured at the center and four peripheral positions of each scanned slice to check phantom homogeneity. Results showed that values for the CTDIw measured in the nylon phantoms were slightly higher than those from the PMMA while CT numbers for nylon were lower than those of PMMA. This is because the mass attenuation coefficient of the nylon is higher. Nylon could be used as a substitute material for CT dosimetry phantom to enable measurements and adjustment factors are given which could be used to estimate PMMA values for making comparisons with displayed values. PMID:27051170

  3. Variations in optical coherence tomography resolution and uniformity: a multi-system performance comparison

    PubMed Central

    Fouad, Anthony; Pfefer, T. Joshua; Chen, Chao-Wei; Gong, Wei; Agrawal, Anant; Tomlins, Peter H.; Woolliams, Peter D.; Drezek, Rebekah A.; Chen, Yu

    2014-01-01

    Point spread function (PSF) phantoms based on unstructured distributions of sub-resolution particles in a transparent matrix have been demonstrated as a useful tool for evaluating resolution and its spatial variation across image volumes in optical coherence tomography (OCT) systems. Measurements based on PSF phantoms have the potential to become a standard test method for consistent, objective and quantitative inter-comparison of OCT system performance. Towards this end, we have evaluated three PSF phantoms and investigated their ability to compare the performance of four OCT systems. The phantoms are based on 260-nm-diameter gold nanoshells, 400-nm-diameter iron oxide particles and 1.5-micron-diameter silica particles. The OCT systems included spectral-domain and swept source systems in free-beam geometries as well as a time-domain system in both free-beam and fiberoptic probe geometries. Results indicated that iron oxide particles and gold nanoshells were most effective for measuring spatial variations in the magnitude and shape of PSFs across the image volume. The intensity of individual particles was also used to evaluate spatial variations in signal intensity uniformity. Significant system-to-system differences in resolution and signal intensity and their spatial variation were readily quantified. The phantoms proved useful for identification and characterization of irregularities such as astigmatism. Our multi-system results provide evidence of the practical utility of PSF-phantom-based test methods for quantitative inter-comparison of OCT system resolution and signal uniformity. PMID:25071949

  4. NDT-COMP9 microcomputer

    SciTech Connect

    Dodd, C.V.; Cowan, R.F.

    1980-09-01

    An 8080-based microcomputer system, the NDT-COMP9, has been designed for instrumentation control and data analysis in eddy-current tests. The NDT-COMP9 represents a significantly more powerful computer system than the NDT-COMP8 microcomputer from which it was developed. The NDT-COMP9 system is contained on a 240- by 120-mm (9.5- by 4.8-in.) circuit board and will fit in a four-wide Nuclear Instrumentation Module (NIM) BIN with 26-pin edge connectors. In addition to the 8080-compatible central processing unit (CPU), an arithmetic processing unit (APU) is available to provide up to 32-bit fixed- or floating-point, basic or transcendental math functions. The 16K of read only memory (ROM) and random access memory (RAM), one serial input-output (I/O) port (RS-232-C at a maximum speed of 9600 baud), and 72 parallel I/O ports are available. The baud rate is under software control. A system monitor and math package are available for use with the microcomputer.

  5. Microcomputer Checks Butt-Weld Accuracy

    NASA Technical Reports Server (NTRS)

    Clisham, W.; Garner, W.; Cohen, C.; Beal, J.; Polen, R.; Lloyd, J.

    1982-01-01

    Electrical gage and microcomputer eliminate time-consuming manual measurements. Alinement and angle of plates on either side of butt weld are measured and recorded automatically by hand-held gage and desk-top microcomputer. Gage/micro-computer quickly determine whether weld is within dimensional tolerances or whether reworking is needed. Microcomputer prints out measurements while operator moves gage from point to point along weld. Out-of-tolerance measurements are marked by an asterisk on printout.

  6. Developing a Library Microcomputing Profile: 101 Spectra to Be Used in Analysis by Microcomputer Managers.

    ERIC Educational Resources Information Center

    Grass, Charlene

    1991-01-01

    Presents 101 variables for use in developing a microcomputing profile and determining the type of microcomputing management appropriate for a library. Variables are presented in 16 categories, including the larger institutional, library, and financial profiles; administration's stance on microcomputing; user profiles; training and support for…

  7. The Impact of Microcomputing on Political Science.

    ERIC Educational Resources Information Center

    Garson, G. David

    1985-01-01

    Future impacts of microcomputing on political science are discussed. Scenarios dealing with networking, data access, field research, course management, and simulations and artificial intelligence are described. (RM)

  8. The Impact of Microcomputing on Political Science.

    ERIC Educational Resources Information Center

    Garson, G. David

    1985-01-01

    Future impacts of microcomputing on political science are discussed. Scenarios dealing with networking, data access, field research, course management, and simulations and artificial intelligence are described. (RM)

  9. Comparison of radiography and computed tomography to evaluate fractures of the canine tarsus.

    PubMed

    Butler, Danielle; Nemanic, Sarah; Warnock, Jennifer J

    2017-09-03

    Detection and accurate classification of traumatic tarsal fractures are important for identifying cases requiring surgical intervention. The aim of this prospective, experimental, methods comparison study was to directly compare the accuracy, sensitivity, and specificity of tarsal computed tomography (CT), ten-view and two-view digital radiographs for detecting traumatic fractures of the canine tarsus. The working hypothesis was that tarsal fractures would be detected with higher accuracy, sensitivity, and specificity using CT imaging compared to radiography, and a ten-view would be superior to a two-view radiographic study. Ten cadaver hind limbs of medium to large dogs received a CT scan and ten-view radiographic study before and after induction of fractures with a hydraulic press. All bones included in the radiographic images were assessed for fractures by two observers and gross dissection was used as the gold standard. The two-view radiographic study (dorsoplantar, lateromedial) was created from the ten-view study and reviewed 2 years later. All limbs sustained fractures, the most common locations were the talus and calcaneus (n = 7). The sensitivity of CT was greater than ten-view radiographic study (77% vs. 57%), while the specificity was similar (97% vs. 98%). The sensitivity and specificity of the ten-view and two-view radiograph studies were similar (57% vs. 55%; both 98%). Computed tomography images were reassessed postdissection to determine if failure to identify fractures resulted from observer error. Overall, CT was better than radiography for detecting fractures of the canine tarsus, however there was little improvement with ten-view compared to two-view radiographic studies. © 2017 American College of Veterinary Radiology.

  10. Special computer-aided computed tomography (CT) volume measurement and comparison method for pulmonary tuberculosis (TB).

    PubMed

    Liu, Jingming; Sun, Zhaogang; Xie, Ruming; Gao, Mengqiu; Li, Chuanyou

    2015-01-01

    The computed tomography (CT) manifestations in pulmonary tuberculosis (PTB) patients are complex and could not be quantitatively evaluated. We aimed to establish a new method to objectively measure the lung injury level in PTB by thoracic CT and make quantitative comparisons. In the retrospective study, a total of 360 adults were selected and divided into four groups according to their CT manifestations and medical history: Normal group, PTB group, PTB with diabetes mellitus (DM) group and Death caused by PTB group. Five additional patients who had continuous CT scans were chosen for preliminary longitudinal analysis. We established a new computer-aided CT volume measurement and comparison method for PTB patients (CACTV-PTB) which measured lung volume (LV) and thoracic volume (TV). RLT was calculated as the ratio of LV to TV and comparisons were performed among different groups. Standardized RLT (SRLT) was used in the longitudinal analysis among different patients. In the Normal group, LV and TV were positively correlated in linear regression (Ŷ=-0.5+0.46X, R(2)=0.796, P<0.01). RLT values were significantly different among four groups (Normal: 0.40±0.05, PTB: 0.37±0.08, PTB+DM: 0.34±0.06, Death: 0.23±0.04). The curves of SRLT value from different patients shared a same start point and could be compared directly. Utilizing the novel objective method CACTV-PTB makes it possible to compare the severity and dynamic change among different PTB patients. Our early experience also suggested that the lung injury is severer in the PTB+DM group than in the PTB group.

  11. Optical Tomography of a Sunspot. I. Comparison between Two Inversion Techniques

    NASA Astrophysics Data System (ADS)

    Westendorp Plaza, C.; del Toro Iniesta, J. C.; Ruiz Cobo, B.; Martínez Pillet, V.; Lites, B. W.; Skumanich, A.

    1998-02-01

    A quantitative comparison between the Milne-Eddington (ME) inversion technique implemented by Skumanich & Lites and the SIR (Stokes Inversion based on Response Functions) proposed by Ruiz Cobo & del Toro Iniesta is presented. Numerical experiments are carried out to explore the capabilities and limitations of both diagnostic techniques. Such experiments consist of inversions of Stokes profiles previously synthesized in ``realistic'' solar atmospheric models. The results show that the ME inversion provides accurate, line-of-sight (LOS) averaged values for the input stratification of the vector magnetic field. Its greater speed compared to SIR makes it useful for quick analysis of large quantities of data (such as those currently provided by modern spectropolarimeters) if one is only interested in LOS-averaged quantities. However, the higher order description of the atmosphere used by SIR (which acknowledges variation of the thermal, dynamic, and magnetic parameters through the photosphere) allows retrieval of the stratification of all these parameters to good accuracy. This is so even in the presence of discontinuities such as those foreseen in magnetic canopies of sunspots. The trade-offs between thermodynamic and magnetic parameters observed in some ME inversions are reduced considerably in the case of SIR inversions because of the more realistic treatment of the thermodynamics in this analysis. Notably, both allow one to extract quantitative inferences of fairly weak magnetic fields (below 500 G), even when they are applied to Zeeman-sensitive lines in the visible spectrum; i.e., well below the commonly accepted limit of 500 G. The thermodynamic parameters resulting from the ME inversion are understood theoretically in terms of the generalized response functions introduced by Ruiz Cobo & del Toro Iniesta and through the concept of height of formation for inferred values proposed by Sánchez Almeida, Ruiz Cobo, & del Toro Iniesta. The present comparison and

  12. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography

    PubMed Central

    Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2015-01-01

    Abstract. A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography (μCT) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In μCT, the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer–Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to 606  μm in SS-OCT. A correlation between μCT and SS-OCT was found regarding lesion depth (R=0.81, p<0.001) and also surface layer thickness (R=0.76, p<0.005). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution μCT without the use of x-ray. PMID:26158079

  13. Assessment of natural enamel lesions with optical coherence tomography in comparison with microfocus x-ray computed tomography.

    PubMed

    Espigares, Jorge; Sadr, Alireza; Hamba, Hidenori; Shimada, Yasushi; Otsuki, Masayuki; Tagami, Junji; Sumi, Yasunori

    2015-01-01

    A technology to characterize early enamel lesions is needed in dentistry. Optical coherence tomography (OCT) is a noninvasive method that provides high-resolution cross-sectional images. The aim of this study is to compare OCT with microfocus x-ray computed tomography ([Formula: see text]) for assessment of natural enamel lesions in vitro. Ten human teeth with visible white spot-like changes on the enamel smooth surface and no cavitation (ICDAS code 2) were subjected to imaging by μCT (SMX-100CT, Shimadzu) and 1300-nm swept-source OCT (Dental SS-OCT, Panasonic Health Care). In [Formula: see text], the lesions appeared as radiolucent dark areas, while in SS-OCT, they appeared as areas of increased signal intensity beneath the surface. An SS-OCT attenuation coefficient based on Beer-Lambert law could discriminate lesions from sound enamel. Lesion depth ranged from 175 to [Formula: see text] in SS-OCT. A correlation between [Formula: see text] and SS-OCT was found regarding lesion depth ([Formula: see text], [Formula: see text]) and also surface layer thickness ([Formula: see text], [Formula: see text]). The images obtained clinically in real time using the dental SS-OCT system are suitable for the assessment of natural subsurface lesions and their surface layer, providing comparable images to a laboratory high-resolution [Formula: see text] without the use of x-ray.

  14. Value and limitation of stress thallium-201 single photon emission computed tomography: comparison with nitrogen-13 ammonia positron tomography

    SciTech Connect

    Tamaki, N.; Yonekura, Y.; Senda, M.; Yamashita, K.; Koide, H.; Saji, H.; Hashimoto, T.; Fudo, T.; Kambara, H.; Kawai, C.

    1988-07-01

    The diagnostic value of exercise /sup 201/Tl single photon emission computed tomography (SPECT) for assessing coronary artery disease (CAD) was comparatively evaluated with exercise (13N) ammonia positron emission tomography (PET). Fifty-one patients underwent both stress-delayed SPECT imaging using a rotational gamma camera and stress-rest PET imaging using a high resolution PET camera. Of 48 CAD patients, SPECT showed abnormal perfusion in 46 patients (96%), while PET detected perfusion abnormalities in 47 (98%). The sensitivity for detecting disease in individual coronary arteries (greater than 50% stenosis) was also similar for SPECT (81%) and PET (88%). When their interpretations were classified as normal, transient defect, and fixed defect in 765 myocardial segments, SPECT and PET findings were concordant in 606 segments (79%). However, 66 segments showed a fixed defect by SPECT but a transient defect by PET, whereas there were only nine segments showing a transient defect by SPECT and a fixed defect by PET. PET identified transient defects in 34% of the myocardial segments showing a fixed defect by SPECT. We conclude that both stress SPECT and PET showed high and similar sensitivities for detecting CAD and individual stenosed vessels. Since stress-delayed SPECT with single tracer injection detected fewer transient defects, it may underestimate the presence of myocardial ischemia, compared with high resolution PET imaging with two tracer injections.

  15. New generation of exploration tools: interactive modeling software and microcomputers

    SciTech Connect

    Krajewski, S.A.

    1986-08-01

    Software packages offering interactive modeling techniques are now available for use on microcomputer hardware systems. These packages are reasonably priced for both company and independent explorationists; they do not require users to have high levels of computer literacy; they are capable of rapidly completing complex ranges of sophisticated geologic and geophysical modeling tasks; and they can produce presentation-quality output for comparison with real-world data. For example, interactive packages are available for mapping, log analysis, seismic modeling, reservoir studies, and financial projects as well as for applying a variety of statistical and geostatistical techniques to analysis of exploration data. More importantly, these packages enable explorationists to directly apply their geologic expertise when developing and fine-tuning models for identifying new prospects and for extending producing fields. As a result of these features, microcomputers and interactive modeling software are becoming common tools in many exploration offices. Gravity and magnetics software programs illustrate some of the capabilities of such exploration tools.

  16. Comparison of objective diagnostic tests in glaucoma: Heidelberg retinal tomography and multifocal visual evoked potentials.

    PubMed

    Balachandran, C; Graham, S L; Klistorner, A; Goldberg, I

    2006-04-01

    To compare sensitivity and specificity of functional and structural changes in glaucoma using two objective tests: the multifocal visual evoked potential (m-VEP) and Heidelberg retinal tomography II (HRT). 41 glaucoma patients and 25 normal individuals participated in the study. One eye per individual was included in the study. Individuals were evaluated with Humphrey visual field (HVF) perimetry, m-VEP, and HRT. Moorfield regression analysis findings of HRT were compared with presence of scotoma on m-VEP. Linear regression analysis of quantitative variables, such as HVF mean deviation (MD), m-VEP discriminant score (Accumap Severity Index) and, global HRT parameters was also performed. m-VEP sensitivity and specificity were 93% and 96% respectively. HRT sensitivity and specificity were 79% and 92% respectively. The area under the receiver operating characteristic curve (ROC) for m-VEP was 0.96 and for HRT varied from 0.79 to 0.86 depending on the parameters used. Linear correlation between MD and Accumap Severity Index score was -77%, while that between HRT global parameters, Accumap Severity Index and MD were at best around 50%. Topographic comparison of the presence of scotoma on HVF and m-VEP in different areas of the visual field showed good agreement. Comparison of optic nerve head structural abnormality with corresponding areas of field defects on HVF and m-VEP showed poor to moderate agreement. The objective test of optic nerve function (m-VEP) and structure (HRT) can detect glaucomatous damage, with limited correlation. The 2 functional tests, HVF and m-VEP correlate better with each other than with HRT. It remains important to look for both functional and structural changes in order to detect all glaucoma cases.

  17. Accuracy of Linear Measurements Using Cone Beam Computed Tomography in Comparison with Clinical Measurements

    PubMed Central

    Rokn, Amir Reza; Hashemi, Kazem; Akbari, Solmaz; Kharazifard, Mohammad Javad; Barikani, Hamidreza; Panjnoosh, Mehrdad

    2016-01-01

    Objectives: This study sought to evaluate the accuracy and errors of linear measurements of mesiodistal dimensions of Kennedy Class III edentulous space using cone beam computed tomography (CBCT) in comparison with clinical measurements. Materials and Methods: Nineteen Kennedy Class III dental arches were evaluated. An impression was made of each dental arch and poured with dental stone. The distance was measured on dental cast using a digital Vernier caliper with an accuracy of 0.1mm and on CBCT scans. Finally, the linear mesiodistal measurements were compared and the accuracy of CBCT technique was evaluated by calculating absolute value of errors, intra-class correlation coefficient and simple linear regression model. Results: In comparison with the cast method, estimation of size on CBCT scans had an error of −8.46% (underestimation) to 5.21% (overestimation). In 26.5% of the cases, an accepted error of ±1% was found. The absolute value of errors was found to be in the range of 0.21–8.46mm with an average value of 2.86 ±2.30mm. Conclusions: Although the measurements revealed statistically significant differences, this does not indicate a lower accuracy for the CBCT technique. In fact, CBCT can provide some information as a paraclinical tool and the clinician can combine these data with clinical data and achieve greater accuracy. Undoubtedly, calibration of data collected by clinical and paraclinical techniques and the clinician’s expertise in use of CBCT software programs can increase the accuracy of implant placement. PMID:28127327

  18. Comparison of Compressed Sensing Algorithms for Inversion of 3-D Electrical Resistivity Tomography.

    NASA Astrophysics Data System (ADS)

    Peddinti, S. R.; Ranjan, S.; Kbvn, D. P.

    2016-12-01

    Image reconstruction algorithms derived from electrical resistivity tomography (ERT) are highly non-linear, sparse, and ill-posed. The inverse problem is much severe, when dealing with 3-D datasets that result in large sized matrices. Conventional gradient based techniques using L2 norm minimization with some sort of regularization can impose smoothness constraint on the solution. Compressed sensing (CS) is relatively new technique that takes the advantage of inherent sparsity in parameter space in one or the other form. If favorable conditions are met, CS was proven to be an efficient image reconstruction technique that uses limited observations without losing edge sharpness. This paper deals with the development of an open source 3-D resistivity inversion tool using CS framework. The forward model was adopted from RESINVM3D (Pidlisecky et al., 2007) with CS as the inverse code. Discrete cosine transformation (DCT) function was used to induce model sparsity in orthogonal form. Two CS based algorithms viz., interior point method and two-step IST were evaluated on a synthetic layered model with surface electrode observations. The algorithms were tested (in terms of quality and convergence) under varying degrees of parameter heterogeneity, model refinement, and reduced observation data space. In comparison to conventional gradient algorithms, CS was proven to effectively reconstruct the sub-surface image with less computational cost. This was observed by a general increase in NRMSE from 0.5 in 10 iterations using gradient algorithm to 0.8 in 5 iterations using CS algorithms.

  19. A comparison of sensors for minimizing the primary signal in planar-array magnetic induction tomography.

    PubMed

    Watson, S; Igney, C H; Dössel, O; Williams, R J; Griffiths, H

    2005-04-01

    In magnetic induction tomography reducing the influence of the primary excitation field on the sensors can provide a significant improvement in SNR and/or allow the operating frequency to be reduced. For the purposes of imaging, it would be valuable if all, or a useful subset, of the detection coils could be rendered insensitive to the primary field for any excitation coil activated. Suitable schemes which have been previously suggested include the use of axial gradiometers and coil-orientation methods (Bx sensors). This paper examines the relative performance of each method through computer simulation of the sensitivity profiles produced by a single sensor, and comparison of reconstructed images produced by sensor arrays. A finite-difference model was used to determine the sensitivity profiles obtained with each type of sensor arrangement. The modelled volume was a cuboid of dimensions 50 cmx50 cmx12 cm with a uniform conductivity of 1 S m-1. The excitation coils were of 5 cm diameter and the detection coils of 5 mm diameter. The Bx sensors provided greater sensitivity than the axial gradiometers at all depths, other than on the surface layer of the volume. Images produced using a single-planar array were found to contain distortion which was reduced by the addition of a second array.

  20. A microcomputer-controlled laser beam analyzer

    NASA Astrophysics Data System (ADS)

    Hand, L. E.; Nagle, H. T., Jr.; Kerns, D. V., Jr.

    1982-07-01

    A microcomputer-controlled laser beam analyzer is described. It uses five INTEL 8080 microcomputers to calculate the beam's peak intensity, peak intensity coordinates, centroid coordinates, beam energy, and beam quality in real time. Its application to the U.S. Army's gas-dynamic laser is illustrated.

  1. Making Work Easy: Administrative Applications of Microcomputers.

    ERIC Educational Resources Information Center

    Schneider, Gail Thierbach

    This survey of the administrative applications of microcomputers identifies word processing, database management, spreadsheet functions, and graphics as four areas in which microcomputer use will reduce repetition, improve cost efficiency, minimize paperwork, enhance filing and retrieval systems, and save time. This will allow administrators and…

  2. Implementing a Microcomputer Database Management System.

    ERIC Educational Resources Information Center

    Manock, John J.; Crater, K. Lynne

    1985-01-01

    Current issues in selecting, structuring, and implementing microcomputer database management systems in research administration offices are discussed, and their capabilities are illustrated with the system used by the University of North Carolina at Wilmington. Trends in microcomputer technology and their likely impact on research administration…

  3. Diversity of Microcomputer Implementations: A Process Perspective.

    ERIC Educational Resources Information Center

    Bond, Elden A.

    1988-01-01

    Discussion of educational innovations and their implementation highlights a study of school principals in Washington State that was conducted to determine whether the microcomputer is similar or fundamentally different to other educational innovations. Attitudes toward the educational use of microcomputers were examined as well as relationships…

  4. Using a Microcomputer in Science Teaching.

    ERIC Educational Resources Information Center

    Rowbotham, Neil

    1981-01-01

    Explores several options and advantages of using microcomputers in science teaching. Describes programs for calculating pH, Maxwell-Boltzman distribution of velocities in a gas, atomic orbitals, and lattice energies. Also suggests use of microcomputers in the areas of simulations, scoring tests, and controlling stock. (DS)

  5. The Apple Microcomputer in School Learning Centers.

    ERIC Educational Resources Information Center

    Russell, John W.

    1982-01-01

    The learning center is a cost-effective and popular way to introduce hearing impaired students and their teachers to microcomputers. (A brief listing of software companies and computer periodicals is included.) The use of the Apple microcomputer in a learning center in a school for the deaf is discussed. (CL)

  6. The Effectiveness of Microcomputers in Education.

    ERIC Educational Resources Information Center

    Ploeger, Floyd D.

    This in-depth review of the literature synthesizes articles and abstracts identified as education-oriented microcomputer research studies published since 1979. A brief, historic overview of educational computing is followed by a review of the Becker (1983) survey, which concerned the distribution of microcomputers in education in the United…

  7. Using the Microcomputer to Develop Listening Skills.

    ERIC Educational Resources Information Center

    Mohler, Stephen C.

    A college-level introductory Spanish instructional system uses an interactive combination of microcomputer and program-stop tape recorder to enhance students' listening skills. The basic content is listening drills, adapted to the computer medium. Microcomputer use adds considerable versatility to instructional materials, including such features…

  8. Microcomputers in Education. Report No. 4798.

    ERIC Educational Resources Information Center

    Feurzeig, W.; And Others

    A brief review of the history of computer-assisted instruction and discussion of the current and potential roles of microcomputers in education introduce this review of the capabilities of state-of-the-art microcomputers and currently available software for them, and some speculations about future trends and developments. A survey of current…

  9. A microcomputer-based preventive maintenance system.

    PubMed

    Rohrer, R A

    1983-01-01

    A medical equipment preventive maintenance system using a Radio Shack microcomputer is described. The system generates a schedule of equipment to be inspected each week. The software is written in BASIC for easy modification or transfer to other commercially available microcomputers. The system has been in use for nine months with good results.

  10. Integrating Mainframe Data Bases on a Microcomputer

    PubMed Central

    Marciniak, Thomas A.

    1985-01-01

    Microcomputers support user-friendly software for interrogating their resident data bases. Many medical data bases currently consist of files on less accessible mainframe computers with more limited inquiry capabilities. We discuss the transferring and integrating of mainframe data into microcomputer data base systems in one medical environment.

  11. Introduction to Microcomputers. Inservice Series No. 16.

    ERIC Educational Resources Information Center

    Wilson, Mary Alice

    This manual is designed to introduce adults to microcomputers. It is planned for use with a series of five two-hour labs on Apple II or IIe computers, with participants expected to review sections and practice on a microcomputer between sessions. The goals are to have participants (1) understand how programing languages work, (2) understand the…

  12. Using Microcomputers in Teaching Vocational Agriculture.

    ERIC Educational Resources Information Center

    Barrick, R. Kirby, Ed.

    This collection of articles is designed to help vocational agriculture teachers use microcomputers in teaching. The guide covers both the different types of software and the ways they can be applied in teaching. The guide is organized in three sections. The first section covers types of programs and includes "Selection of Microcomputer Hardware…

  13. The Microcomputer-Based Science Laboratory.

    ERIC Educational Resources Information Center

    Bross, Thomas R.

    1986-01-01

    Discusses the use of microcomputers in science education: (1) computer-assisted instruction; (2) testing; (3) data processing; (4) simulation; (5) teacher assistance; and (6) data collection. Gives educational applications of microcomputer-based laboratories, pointing out advantages and disadvantages. Outlines current drawbacks and makes…

  14. Microcomputer Database Management Systems for Bibliographic Data.

    ERIC Educational Resources Information Center

    Pollard, Richard

    1986-01-01

    Discusses criteria for evaluating microcomputer database management systems (DBMS) used for storage and retrieval of bibliographic data. Two popular types of microcomputer DBMS--file management systems and relational database management systems--are evaluated with respect to these criteria. (Author/MBR)

  15. Implementing a Microcomputer Database Management System.

    ERIC Educational Resources Information Center

    Manock, John J.; Crater, K. Lynne

    1985-01-01

    Current issues in selecting, structuring, and implementing microcomputer database management systems in research administration offices are discussed, and their capabilities are illustrated with the system used by the University of North Carolina at Wilmington. Trends in microcomputer technology and their likely impact on research administration…

  16. Use of Microcomputers to Prepare Scientific Documents.

    ERIC Educational Resources Information Center

    Ristroph, John H.

    1987-01-01

    Presents methods for preparing technical documents on microcomputers by modifying WordStar and using inexpensive software to create scientific symbols and other characters needed. Procedures are described for use with a Zenith A-100 microcomputer and an Epson FX dot matrix printer, and may be adapted for other configurations. (LRW)

  17. Microcomputers in Special Education: Promises and Pitfalls.

    ERIC Educational Resources Information Center

    Budoff, Milton; Hutten, Leah R.

    1982-01-01

    The paper indicates major features of microcomputer systems and suggests limitations of the current microcomputer systems for special education applications. Many questions about the effectiveness of computer assisted instruction with special populations remain. Teachers must become computer literate, knowledgeable in instructional classroom…

  18. Preschooler's Use of Microcomputers and Input Devices.

    ERIC Educational Resources Information Center

    King, John; Alloway, Nola

    1992-01-01

    Describes a study that measured preschoolers' use of microcomputers in the following areas: (1) efficiency of use of input devices, including the keyboard, the joystick, and the mouse; (2) use during free-play activities, including interaction with the microcomputer and with each other; and (3) gender differences. (40 references) (LRW)

  19. Microcomputer Usage in Schools, 1984-1985.

    ERIC Educational Resources Information Center

    Quality Education Data, Inc., Denver, CO.

    Results are presented for the fourth annual survey of all U.S. school districts by Quality Educational Data, Inc. Findings are displayed in tabular form and include information on the following: market penetration by major brands of microcomputers in school districts and buildings; school districts that use microcomputers and the brand or…

  20. Microcomputer Polling Improvements for AFSATCOM.

    DTIC Science & Technology

    1981-06-01

    SBC 80/20 SINGLE BOARD COMPUTER 28 5.2 NATIONAL SEMICONDUCTOR BLC 416 16K PROM BOARD 32 5.3 INTEL 450 16K RAM BOARD 32 5.4 I/O AND DISPLAY CIRCUITS 32...Data Adapter (Sheet 6) 41 5-10 SBC 80/20 Single Board Computer Interfaces (Sheet 7) 42 5-11 Slot Counter/Display (Sheet 8) 43 5-12 RS-232 Serial...report describes a breadb6ard microcomputer system based on an Intel SBC 80/20 Single Board Computer (SBC) which fulfills the project demonstration

  1. Different intravenous contrast media concentrations do not affect clinical assessment of 18F-fluorodeoxyglucose positron emission tomography/computed tomography scans in an intraindividual comparison.

    PubMed

    Prechtel, Hans W E; Verburg, Frederik A; Palmowski, Moritz; Krohn, Thomas; Pietsch, Hubertus; Kuhl, Christiane K; Mottaghy, Felix M; Behrendt, Florian F

    2012-09-01

    The purpose of this study was to perform an intraindividual comparison of the influences of different iodine contrast media on tracer uptake, contrast enhancement, and image quality in combined positron emission tomography (PET)/computed tomography (CT). Fifty-one patients underwent baseline and follow-up combined PET/CT consisting of low-dose unenhanced and venous contrast-enhanced CT with contrast media containing a high concentration of iodine (iopromide, 370 mg/mL) and a standard iodine concentration (iopromide, 300 mg/mL). The total iodine load (44.4 g) and the iodine delivery rate (1.29 g/s) were identical for the 2 protocols. The mean and maximum standard uptake values, as measures of tracer uptake and contrast enhancement for unenhanced and contrast-enhanced PET/CT, were quantified at 10 different anatomical sites, and images were analyzed for clinically relevant differences. The mean and maximum standard uptake values were significantly increased in contrast-enhanced PET/CT compared with unenhanced PET/CT at each anatomical site (P < 0.05). Comparison of tracer uptake between the 300- and 370-mg iodine contrast media showed no significant differences (all P > 0.05). Comparison of contrast enhancement between the 300- and 370-mg iodine contrast media showed no significant difference at any anatomical site (all P > 0.05). Analysis of image quality revealed no clinically relevant differences between the 2 different iodine contrast media (P = 0.739). The use of contrast-enhanced CT scans for attenuation correction in PET/CT does not cause clinically relevant artifacts in PET scan reconstruction, regardless of the iodine concentration used. Standard- and high-iodine contrast media can be used equivalently.

  2. Anatomical analysis of turgescent and semi-dry resurrection plants: the effect of sample preparation on the sample, resolution, and image quality of X-ray micro-computed tomography (μCT).

    PubMed

    Korte, Nikola; Porembski, Stefan

    2011-04-01

    Computer tomography has been used frequently for the 3-D visualization of plant anatomical traits but sample preparation has been widely neglected. Without any preparation smaller (i.e., up to 1 × 1 cm(2) ) turgescent or semi-dry plant samples (especially leaf samples) diminish the image quality of a scan due to gradual water loss and therefore constant movement. A suitable preparation for scans of turgescent and semi-dry plant samples with a high resolution μCT (<1-5 μm) has to be very thin, heat-resistant (up to 35°C), have a low attenuation coefficient, and should not alter the water content and structure of the sample. Several agents have been tested, but only a coating with vaseline conserved the water content of a plant sample efficiently. However, water molecules and vaseline both attenuate the X-ray beam, which decreases the image quality of scans of turgescent or semi-dry plant samples. Therefore, trade-offs between the spatial resolution, sample water content, sample size, and image quality have to be considered: larger samples have to be placed further away from the X-ray tube, which leads to a lower spatial resolution; water and preparation agents attenuate the X-ray beam, causing low-quality images which may be accompanied by motion artifacts compared to a scan of a dry sample, where no preparation is necessary.

  3. Comparison of diffraction-enhanced computed tomography and monochromatic synchrotron radiation computed tomography of human trabecular bone.

    PubMed

    Connor, D M; Hallen, H D; Lalush, D S; Sumner, D R; Zhong, Z

    2009-10-21

    Diffraction-enhanced imaging (DEI) is an x-ray-based medical imaging modality that, when used in tomography mode (DECT), can generate a three-dimensional map of both the apparent absorption coefficient and the out-of-plane gradient of the index of refraction of the sample. DECT is known to have contrast gains over monochromatic synchrotron radiation CT (SRCT) for soft tissue structures. The goal of this experiment was to compare contrast-to-noise ratio (CNR) and resolution in images of human trabecular bone acquired using SRCT with images acquired using DECT. All images were acquired at the National Synchrotron Light Source (Upton, NY, USA) at beamline X15 A at an x-ray energy of 40 keV and the silicon [3 3 3] reflection. SRCT, apparent absorption DECT and refraction DECT slice images of the trabecular bone were created. The apparent absorption DECT images have significantly higher spatial resolution and CNR than the corresponding SRCT images. Thus, DECT will prove to be a useful tool for imaging applications in which high contrast and high spatial resolution are required for both soft tissue features and bone.

  4. Quantitative analysis of brain edema and swelling on early postmortem computed tomography: comparison with antemortem computed tomography.

    PubMed

    Takahashi, Naoya; Satou, Chihiro; Higuchi, Takeshi; Shiotani, Motoi; Maeda, Haruo; Hirose, Yasuo

    2010-06-01

    The aim of this study was quantitatively to analyze brain edema and swelling due to early postmortem changes using computed tomography (CT) scans of the head. Review board approval was obtained, and informed consent was waived. A total of 41 patients who underwent head CT before and shortly after death were enrolled. Hounsfield units (HUs) of gray matter (GM) and white matter (WM) were measured at the levels of the basal ganglia, centrum semiovale, and high convexity area on both antemortem and postmortem CT. The length of the minor axis of the third ventricle at the level of the basal ganglia and the width of the central sulcus at the level of high convexity were measured. At each level tested, the HUs of GM and the GM/WM ratios on postmortem CT were significantly lower than those on antemortem CT (P < 0.001). HUs of WM on postmortem CT were slightly higher than those on antemortem CT but without significant difference (P > 0.1). Postmortem CT showed subtle loss of distinction between GM and WM. The size of the third ventricle and the width of the central sulcus did not vary before and after death (P > 0.1). Early postmortem CT shows mild brain edema but does not show brain swelling.

  5. Value of image fusion using single photon emission computed tomography with integrated low dose computed tomography in comparison with a retrospective voxel-based method in neuroendocrine tumours.

    PubMed

    Amthauer, H; Denecke, T; Rohlfing, T; Ruf, J; Böhmig, M; Gutberlet, M; Plöckinger, U; Felix, R; Lemke, A J

    2005-07-01

    The objective was the evaluation of single photon emission computed tomography (SPECT) with integrated low dose computed tomography (CT) in comparison with a retrospective fusion of SPECT and high-resolution CT and a side-by-side analysis for lesion localisation in patients with neuroendocrine tumours. Twenty-seven patients were examined by multidetector CT. Additionally, as part of somatostatin receptor scintigraphy (SRS), an integrated SPECT-CT was performed. SPECT and CT data were fused using software with a registration algorithm based on normalised mutual information. The reliability of the topographic assignment of lesions in SPECT-CT, retrospective fusion and side-by-side analysis was evaluated by two blinded readers. Two patients were not enrolled in the final analysis because of misregistrations in the retrospective fusion. Eighty-seven foci were included in the analysis. For the anatomical assignment of foci, SPECT-CT and retrospective fusion revealed overall accuracies of 91 and 94% (side-by-side analysis 86%). The correct identification of foci as lymph node manifestations (n=25) was more accurate by retrospective fusion (88%) than from SPECT-CT images (76%) or by side-by-side analysis (60%). Both modalities of image fusion appear to be well suited for the localisation of SRS foci and are superior to side-by-side analysis of non-fused images especially concerning lymph node manifestations.

  6. Microcomputer Use in Higher Education. Executive Summary of a Survey.

    ERIC Educational Resources Information Center

    Lukesh, Susan S.; And Others

    This executive summary of the 1986 Survey of Microcomputers in Higher Education presents the highlights of each of the major areas covered by the survey: (1) general policy; (2) microcomputer availability; (3) microcomputer access; (4) microcomputer acquisition; (5) software availability; and (6) software support. The 211 survey respondents were…

  7. High-resolution 3D analyses of the shape and internal constituents of small volcanic ash particles: The contribution of SEM micro-computed tomography (SEM micro-CT)

    NASA Astrophysics Data System (ADS)

    Vonlanthen, Pierre; Rausch, Juanita; Ketcham, Richard A.; Putlitz, Benita; Baumgartner, Lukas P.; Grobéty, Bernard

    2015-02-01

    The morphology of small volcanic ash particles is fundamental to our understanding of magma fragmentation, and in transport modeling of volcanic plumes and clouds. Until recently, the analysis of 3D features in small objects (< 250 μm) was either restricted to extrapolations from 2D approaches, partial stereo-imaging, or CT methods having limited spatial resolution and/or accessibility. In this study, an X-ray computed-tomography technique known as SEM micro-CT, also called 3D X-ray ultramicroscopy (3D XuM), was used to investigate the 3D morphology of small volcanic ash particles (125-250 μm sieve fraction), as well as their vesicle and microcrystal distribution. The samples were selected from four stratigraphically well-established tephra layers of the Meerfelder Maar (West Eifel Volcanic Field, Germany). Resolution tests performed on a Beametr v1 pattern sample along with Monte Carlo simulations of X-ray emission volumes indicated that a spatial resolution of 0.65 μm was obtained for X-ray shadow projections using a standard thermionic SEM and a bulk brass target as X-ray source. Analysis of a smaller volcanic ash particle (64-125 μm sieve fraction) showed that features with volumes > 20 μm3 (~ 3.5 μm in diameter) can be successfully reconstructed and quantified. In addition, new functionalities of the Blob3D software were developed to allow the particle shape factors frequently used as input parameters in ash transport and dispersion models to be calculated. This study indicates that SEM micro-CT is very well suited to quantify the various aspects of shape in fine volcanic ash, and potentially also to investigate the 3D morphology and internal structure of any object < 0.1 mm3.

  8. Qualitative Comparison of Noncontrast Head Dual-Energy Computed Tomography Using Rapid Voltage Switching Technique and Conventional Computed Tomography.

    PubMed

    Hwang, William D; Mossa-Basha, Mahmud; Andre, Jalal B; Hippe, Daniel S; Culbertson, Scott; Anzai, Yoshimi

    2016-01-01

    Dual-energy computed tomography (DECT) allows image reconstruction along a spectrum of virtual monochromatic energy levels. We sought to determine the optimal energy level(s) for viewing supratentorial brain and posterior fossa and compare those to polychromatic conventional CT (CCT). Furthermore, we compared 2 groups scanned with separate DECT imaging protocols. In addition, we quantify the radiation dose of DECT versus CCT. Forty-four nonacute patients underwent noncontrast DECT and recent CCT on the same scanner. Dual-energy CT images of the head were reconstructed at 5 keV intervals from 50 to 100 keV and randomized with CCT for blinded reader analysis. Evaluation of gray-white matter differentiation, posterior fossa artifact, and overall image noise was performed in consensus using a 5-point scale. In addition, the CTDIvol was compared with CCT examinations. Optimal monochromatic viewing levels in evaluating gray-white matter differentiation were 50 to 55 keV and 50 to 60 keV, using regular-dose DECT (R-DECT) and low-dose DECT (L-DECT), respectively. The optimal levels for mitigating posterior fossa artifacts were 80 to 100 keV utilizing both R-DECT and L-DECT, whereas the optimal viewing levels for improved overall image noise were 60 to 65 keV and 65 to 70 keV for R-DECT and L-DECT, respectively. Readers favored both DECT techniques over CCT. The CTDIvol for DECT was 10% and 37% lower than CCT without a statistically significant reduction in image quality. Optimized noncontrast DECT compared favorably to CCT, with a significant dose reduction benefit.

  9. Chronic thromboembolic pulmonary hypertension: Comparison of dual-energy computed tomography and single photon emission computed tomography in canines.

    PubMed

    Tang, Chun Xiang; Yang, Gui Fen; Schoepf, U Joseph; Han, Zong Hong; Qi, Li; Zhao, Yan E; Wu, Jiang; Zhou, Chang Sheng; Zhu, Hong; Stubenrauch, Andrew C; Mangold, Stefanie; Zhang, Long Jiang; Lu, Guang Ming

    2016-02-01

    To compare diagnostic accuracy between dual-energy CT lung perfused blood volume (Lung PBV) imaging and single photon emission computed tomography (SPECT) in detecting chronic thromboembolic pulmonary hypertension (CTEPH) with histopathological results as reference standard in a canine model. Eighteen CTEPH canines were included into this experimental study. All procedures including paracentesis, embolization, scanning, pressure measurement and feeding medicine were repeated each two weeks, until systolic/diastolic pressure in canines was ≥ 30/15 mm Hg or mean pulmonary artery pressure ≥ 20 mm Hg, and then sacrificed for histopathology examination. Two radiologists (readers 1 and 2) and two nuclear radiologists (readers 3 and 4) analyzed images of conventional CT pulmonary angiography in dual-energy CT mode, Lung PBV imaging and SPECT, respectively. The presence, numbers, and locations of pulmonary emboli (PE) were recorded on a per-lobe basis. Pathological examination was served as reference standard. Sensitivity, specificity and accuracy of Lung PBV and SPECT were calculated. Kappa statistics were used to quantify inter-reader agreement. With histopathological results as reference standard, the sensitivities of 72.2%, 78.8%, 81.2%, specificities of 75.9%, 87.5%, 84.8%, accuracies of 73.8%, 83.1%, 83.1%, for readers 1, 2 and both with Lung PBV, respectively. Readers 3, 4 and both had sensitivities of 14.3%, 25.7%, 33.3%, specificities of 90.0%, 86.7%, 93.3%, accuracies of 49.2%, 53.8%, 60.0% with SPECT for detecting CTEPH. Inter-reader agreements were good for dual-energy CT (kappa=0.662) and SPECT (k=0.706) for detecting CTEPH. Dual-energy CT had a higher accuracy to detect CTEPH than SPECT in this canine model study. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  10. Shaping Ability of Single-file Systems with Different Movements: A Micro-computed Tomographic Study

    PubMed Central

    Santa-Rosa, Joedy; de Sousa-Neto, Manoel Damião; Versiani, Marco Aurelio; Nevares, Giselle; Xavier, Felipe; Romeiro, Kaline; Cassimiro, Marcely; Leoni, Graziela Bianchi; de Menezes, Rebeca Ferraz; Albuquerque, Diana

    2016-01-01

    Introduction: This study aimed to perform a rigorous sample standardization and also evaluate the preparation of mesiobuccal (MB) root canals of maxillary molars with severe curvatures using two single-file engine-driven systems (WaveOne with reciprocating motion and OneShape with rotary movement), using micro-computed tomography (micro-CT). Methods and Materials: Ten MB roots with single canals were included, uniformly distributed into two groups (n=5). The samples were prepared with a WaveOne or OneShape files. The shaping ability and amount of canal transportation were assessed by a comparison of the pre- and post-instrumentation micro-CT scans. The Kolmogorov-Smirnov and t-tests were used for statistical analysis. The level of significance was set at 0.05. Results: Instrumentation of canals increased their surface area and volume. Canal transportation occurred in coronal, middle and apical thirds and no statistical difference was observed between the two systems (P>0.05). In apical third, significant differences were found between groups in canal roundness (in 3 mm level) and perimeter (in 3 and 4 mm levels) (P<0.05). Conclusion: The WaveOne and One Shape single-file systems were able to shape curved root canals, producing minor changes in the canal curvature. PMID:27471537

  11. Structure-function relationships using spectral-domain optical coherence tomography: comparison with scanning laser polarimetry.

    PubMed

    Aptel, Florent; Sayous, Romain; Fortoul, Vincent; Beccat, Sylvain; Denis, Philippe

    2010-12-01

    To evaluate and compare the regional relationships between visual field sensitivity and retinal nerve fiber layer (RNFL) thickness as measured by spectral-domain optical coherence tomography (OCT) and scanning laser polarimetry. Prospective cross-sectional study. One hundred and twenty eyes of 120 patients (40 with healthy eyes, 40 with suspected glaucoma, and 40 with glaucoma) were tested on Cirrus-OCT, GDx VCC, and standard automated perimetry. Raw data on RNFL thickness were extracted for 256 peripapillary sectors of 1.40625 degrees each for the OCT measurement ellipse and 64 peripapillary sectors of 5.625 degrees each for the GDx VCC measurement ellipse. Correlations between peripapillary RNFL thickness in 6 sectors and visual field sensitivity in the 6 corresponding areas were evaluated using linear and logarithmic regression analysis. Receiver operating curve areas were calculated for each instrument. With spectral-domain OCT, the correlations (r(2)) between RNFL thickness and visual field sensitivity ranged from 0.082 (nasal RNFL and corresponding visual field area, linear regression) to 0.726 (supratemporal RNFL and corresponding visual field area, logarithmic regression). By comparison, with GDx-VCC, the correlations ranged from 0.062 (temporal RNFL and corresponding visual field area, linear regression) to 0.362 (supratemporal RNFL and corresponding visual field area, logarithmic regression). In pairwise comparisons, these structure-function correlations were generally stronger with spectral-domain OCT than with GDx VCC and with logarithmic regression than with linear regression. The largest areas under the receiver operating curve were seen for OCT superior thickness (0.963 ± 0.022; P < .001) in eyes with glaucoma and for OCT average thickness (0.888 ± 0.072; P < .001) in eyes with suspected glaucoma. The structure-function relationship was significantly stronger with spectral-domain OCT than with scanning laser polarimetry, and was better expressed

  12. Comparison of optical coherence tomography assessments in the comparison of age-related macular degeneration treatments trials.

    PubMed

    Folgar, Francisco A; Jaffe, Glenn J; Ying, Gui-Shuang; Maguire, Maureen G; Toth, Cynthia A

    2014-10-01

    To determine agreement between spectral-domain (SD) and time-domain (TD) optical coherence tomography (OCT) image assessments by certified readers in eyes treated for neovascular age-related macular degeneration (AMD). Cross-sectional study within the Comparison of AMD Treatments Trials (CATT). During year 2 of CATT, 1213 pairs of SD OCT and TD OCT scans were compared from a subset of 384 eyes. Masked readers independently graded OCT scans for presence of intraretinal fluid (IRF), subretinal fluid (SRF), and sub-retinal pigment epithelium (RPE) fluid and performed manual measurements of retinal, SRF, and subretinal tissue complex thicknesses at the foveal center. Presence of fluid was evaluated with percent agreement, κ coefficients with 95% confidence intervals (CIs), and McNemar tests. Thickness measurements were evaluated with mean difference (Δ) ±95% limits of agreement and intraclass correlation coefficients (ICCs) with 95% CIs. Between SD OCT and TD OCT, agreement on presence of any fluid was 82% (κ = 0.46; 95% CI, 0.40-0.52), with 5% more SD OCT scans demonstrating fluid (P<0.001). Agreement on presence of SRF was 87% and sub-RPE fluid was 80%, with more SD OCT scans demonstrating fluid (both P < 0.001). Agreement on IRF was 73% (κ = 0.47; 95% CI, 0.42-0.52), with 6% more TD OCT scans demonstrating fluid (P < 0.001). Between SD OCT and TD OCT, mean thickness of the retina was Δ = 5±67 μm, SRF was Δ = 1.5±35 μm, and subretinal tissue complex was Δ = 5±86 μm. Thickness measurements were reproducible for retina (ICC = 0.84; 95% CI, 0.83-0.86), SRF (ICC = 0.88; 95% CI, 0.86-0.89), and subretinal tissue complex (ICC = 0.91; 95% CI, 0.89-0.92), with ≤25-μm difference in these measurements in 71%, 94%, and 61% of paired scans, respectively. Agreement on fluid presence and manual thickness measurements between paired scans from each OCT modality was moderate, providing a reasonable basis to compare CATT results with future SD OCT-based trials. Fluid

  13. Life sciences flight experiments microcomputer

    NASA Technical Reports Server (NTRS)

    Bartram, Peter N.

    1987-01-01

    A promising microcomputer configuration for the Spacelab Life Sciences Lab. Equipment inventory consists of multiple processors. One processor's use is reserved, with additional processors dedicated to real time input and output operations. A simple form of such a configuration, with a processor board for analog to digital conversion and another processor board for digital to analog conversion, was studied. The system used digital parallel data lines between the boards, operating independently of the system bus. Good performance of individual components was demonstrated: the analog to digital converter was at over 10,000 samples per second. The combination of the data transfer between boards with the input or output functions on each board slowed performance, with a maximum throughput of 2800 to 2900 analog samples per second. Any of several techniques, such as use of the system bus for data transfer or the addition of direct memory access hardware to the processor boards, should give significantly improved performance.

  14. 275 C Downhole Microcomputer System

    SciTech Connect

    Chris Hutchens; Hooi Miin Soo

    2008-08-31

    An HC11 controller IC and along with serial SRAM and ROM support ICs chip set were developed to support a data acquisition and control for extreme temperature/harsh environment conditions greater than 275 C. The 68HC11 microprocessor is widely used in well logging tools for control, data acquisition, and signal processing applications and was the logical choice for a downhole controller. This extreme temperature version of the 68HC11 enables new high temperature designs and additionally allows 68HC11-based well logging tools and MWD tools to be upgraded for high temperature operation in deep gas reservoirs, The microcomputer chip consists of the microprocessor ALU, a small boot ROM, 4 kbyte data RAM, counter/timer unit, serial peripheral interface (SPI), asynchronous serial interface (SCI), and the A, B, C, and D parallel ports. The chip is code compatible with the single chip mode commercial 68HC11 except for the absence of the analog to digital converter system. To avoid mask programmed internal ROM, a boot program is used to load the microcomputer program from an external mask SPI ROM. A SPI RAM IC completes the chip set and allows data RAM to be added in 4 kbyte increments. The HC11 controller IC chip set is implemented in the Peregrine Semiconductor 0.5 micron Silicon-on-Sapphire (SOS) process using a custom high temperature cell library developed at Oklahoma State University. Yield data is presented for all, the HC11, SPI-RAM and ROM. The lessons learned in this project were extended to the successful development of two high temperature versions of the LEON3 and a companion 8 Kbyte SRAM, a 200 C version for the Navy and a 275 C version for the gas industry.

  15. Comparison of a Novel Weightbearing Cone Beam Computed Tomography Scanner Versus a Conventional Computed Tomography Scanner for Measuring Patellar Instability

    PubMed Central

    Marzo, John; Kluczynski, Melissa; Notino, Anthony; Bisson, Leslie

    2016-01-01

    Background: Conventional computed tomography (CT) images are routinely used for diagnosing patellofemoral instability and are obtained with the patient in a supine position, nonweightbearing, with the knee in full extension, and with leg muscles relaxed. A new portable extremity cone beam CT (CBCT) scanner has been developed that may allow for more accurate diagnosis, as imaging can be performed with the patient standing, the knee flexed, and with leg muscles active. Purpose/Hypothesis: The purpose of this study was to compare CT measurements of patellar alignment on a prototype scanner versus conventional scanner in patients with known patellar instability. The hypothesis was that the measurements obtained with the knee flexed and the patient weightbearing would be less than those obtained from the conventional CT scan. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Twenty patients with a diagnosis of lateral patellar instability were imaged on both a conventional CT scanner and on a prototype CBCT scanner. Objective measures of patellofemoral alignment (tilt angle, congruence angle, tibial tuberosity–trochlear groove [TT-TG] offset) were assessed on images obtained from the prototype and conventional CT scans by 2 independent reviewers. Paired t tests were calculated to compare the mean measurement of patellofemoral alignment obtained from the prototype versus conventional CT. Interrater reliability was assessed using a 2-way mixed-effects model intraclass correlation coefficient (ICC) for tilt angle, congruence angle, and TT-TG offset on the prototype and conventional CT scans. Results: Measurements of patellofemoral alignment were significantly less when acquired by the new prototype CBCT scanner while subjects were weightbearing on a flexed knee. On the images from the prototype CBCT scan, the tilt angle averaged 18.2° ± 11.6° compared with 28.1° ± 7.1° on the conventional CT scan (P < .0001). The congruence angle was 3.0° ± 30

  16. Computed Tomography Number Measurement Consistency Under Different Beam Hardening Conditions: Comparison Between Dual-Energy Spectral Computed Tomography and Conventional Computed Tomography Imaging in Phantom Experiment.

    PubMed

    He, Tian; Qian, Xiaojun; Zhai, Renyou; Yang, Zongtao

    2015-01-01

    To compare computed tomography (CT) number measurement consistency under different beam hardening conditions in phantom experiment between dual-energy spectral CT and conventional CT imaging. A phantom with 8 cells in periphery region and 1 cell in central region were used. The 8 conditioning tubes in the periphery region were filled with 1 of the 3 iodine solutions to simulate different beam hardening conditions: 0 for no beam hardening (NBH), 20 mg/mL for weak beam hardening (WBH) and 50 mg/mL for severe beam hardening (SBH) condition. Test tube filled with 0, 0.1, 0.5, 1, 2, 5, 10, 20, and 50 mg/mL iodine solution was placed in the central cell alternately. The phantom was scanned with conventional CT mode with 80, 100, 120, and 140 kVp and dual energy spectral CT mode. For spectral CT, 11 monochromatic image sets from 40 to 140 keV with interval of 10 keV were reconstructed. The CT number shift caused by beam hardening was evaluated by measuring the CT number difference (ΔCT) with and without beam hardening, with the following formulas: ΔCTWBH = |CTWBH - CTNBH| and ΔCTSBH = |CTSBH - CTNBH|. Data were compared with 1-way analysis of variance. Under both WBH and SBH conditions, the CT number shifts in all monochromatic image sets were less than those for polychromatic images (all P < 0.001). Under WBH condition, the maximum CT number shift was less than 6 Hounsfield units for monochromatic spectral CT images of all energy levels; under SBH condition, only monochromatic images at 70 keV and 80 keV had CT number shift less than 6 HU. Dual energy spectral CT imaging provided more accurate CT number measurement than conventional CT under various beam hardening conditions. The optimal keV level for monochromatic spectral CT images with the most accurate CT number measurement depends on the severities of beam hardening condition.

  17. Computed Tomography Number Measurement Consistency Under Different Beam Hardening Conditions: Comparison Between Dual-Energy Spectral Computed Tomography and Conventional Computed Tomography Imaging in Phantom Experiment

    PubMed Central

    He, Tian; Qian, Xiaojun; Zhai, Renyou; Yang, Zongtao

    2015-01-01

    Purpose To compare computed tomography (CT) number measurement consistency under different beam hardening conditions in phantom experiment between dual-energy spectral CT and conventional CT imaging. Materials and Methods A phantom with 8 cells in periphery region and 1 cell in central region were used. The 8 conditioning tubes in the periphery region were filled with 1 of the 3 iodine solutions to simulate different beam hardening conditions: 0 for no beam hardening (NBH), 20 mg/mL for weak beam hardening (WBH) and 50 mg/mL for severe beam hardening (SBH) condition. Test tube filled with 0, 0.1, 0.5, 1, 2, 5, 10, 20, and 50 mg/mL iodine solution was placed in the central cell alternately. The phantom was scanned with conventional CT mode with 80, 100, 120, and 140 kVp and dual energy spectral CT mode. For spectral CT, 11 monochromatic image sets from 40 to 140 keV with interval of 10 keV were reconstructed. The CT number shift caused by beam hardening was evaluated by measuring the CT number difference (ΔCT) with and without beam hardening, with the following formulas: ΔCTWBH = |CTWBH − CTNBH| and ΔCTSBH = |CTSBH − CTNBH|. Data were compared with 1-way analysis of variance. Results Under both WBH and SBH conditions, the CT number shifts in all monochromatic image sets were less than those for polychromatic images (all P < 0.001). Under WBH condition, the maximum CT number shift was less than 6 Hounsfield units for monochromatic spectral CT images of all energy levels; under SBH condition, only monochromatic images at 70 keV and 80 keV had CT number shift less than 6 HU. Conclusion Dual energy spectral CT imaging provided more accurate CT number measurement than conventional CT under various beam hardening conditions. The optimal keV level for monochromatic spectral CT images with the most accurate CT number measurement depends on the severities of beam hardening condition. PMID:26196347

  18. A Microcomputer-Based Computer Science Program.

    ERIC Educational Resources Information Center

    Compeau, Larry D.

    1984-01-01

    Examines the use of the microcomputer in computer science programs as an alternative to time-sharing computers at North Country Community College. Discusses factors contributing to the program's success, security problems, outside application possibilities, and program implementation concerns. (DMM)

  19. The Seven Deadly Sins of Online Microcomputing.

    ERIC Educational Resources Information Center

    King, Alan

    1989-01-01

    Offers suggestions for avoiding common errors in online microcomputer use. Areas discussed include learning the basics; hardware protection; backup options; hard disk organization; software selection; file security; and the use of dedicated communications lines. (CLB)

  20. Microcomputer-Aided Control Systems Design.

    ERIC Educational Resources Information Center

    Roat, S. D.; Melsheimer, S. S.

    1987-01-01

    Describes a single input/single output feedback control system design program for IBM PC and compatible microcomputers. Uses a heat exchanger temperature control loop to illustrate the various applications of the program. (ML)