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Sample records for microcomputed tomography comparison

  1. 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.

  2. 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.

  3. 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. PMID:26440617

  4. 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.

  5. 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.

  6. 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

  7. Microcomputed Tomography Characterization of Neovascularization in Bone Tissue Engineering Applications

    PubMed Central

    Young, Simon; Kretlow, James D.; Nguyen, Charles; Bashoura, Alex G.; Baggett, L. Scott; Jansen, John A.; Wong, Mark

    2008-01-01

    Abstract Vasculogenesis and angiogenesis have been studied for decades using numerous in vitro and in vivo systems, fulfilling the need to elucidate the mechanisms involved in these processes and to test potential therapeutic agents that inhibit or promote neovascularization. Bone tissue engineering in particular has benefited from the application of proangiogenic strategies, considering the need for an adequate vascular supply during healing and the challenges associated with the vascularization of scaffolds implanted in vivo. Conventional methods of assessing the in vivo angiogenic response to tissue-engineered constructs tend to rely on a two-dimensional assessment of microvessel density within representative histological sections without elaboration of the true vascular tree. The introduction of microcomputed tomography (micro-CT) has recently allowed investigators to obtain a diverse range of high-resolution, three-dimensional characterization of structures, including renal, coronary, and hepatic vascular networks, as well as bone formation within healing defects. To date, few studies have utilized micro-CT to study the vascular response to an implanted tissue engineering scaffold. In this paper, conventional in vitro and in vivo models for studying angiogenesis will be discussed, followed by recent developments in the use of micro-CT for vessel imaging in bone tissue engineering research. A new study demonstrating the potential of contrast-enhanced micro-CT for the evaluation of in vivo neovascularization in bony defects is described, which offers significant potential in the evaluation of bone tissue engineering constructs. PMID:18657028

  8. 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.

  9. Visualization of three-dimensional nephron structure with microcomputed tomography.

    PubMed

    Bentley, Michael D; Jorgensen, Steven M; Lerman, Lilach O; Ritman, Erik L; Romero, J Carlos

    2007-03-01

    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 microm. At 6 microm 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 microm 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.

  10. 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.

  11. Three-dimensional X-ray micro-computed tomography analysis of polymerization shrinkage vectors in flowable composite.

    PubMed

    Takemura, Yukihiko; Hanaoka, Koji; Kawamata, Ryota; Sakurai, Takashi; Teranaka, Toshio

    2014-01-01

    The polymerization shrinkage of flowable resin composites was evaluated using air bubbles as traceable markers. Three different surface treatments i.e. an adhesive silane coupling agent, a separating silane coupling agent, and a combination of both, were applied to standard cavities. Before and after polymerization, X-ray micro-computed tomography images were recorded. Their superimposition and comparison allowed position changes of the markers to be visualized as vectors. The movement of the markers in the resin composite was, therefore, quantitatively evaluated from the tomographic images. Adhesion was found to significantly influence shrinkage patterns. The method used here could be employed to visualize shrinkage vectors and shrinkage volume. PMID:24988881

  12. 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.

  13. Geometric classification of open-cell metal foams using X-ray micro-computed tomography

    SciTech Connect

    Bock, Jessica Jacobi, Anthony M.

    2013-01-15

    The geometry of foams has long been an area of interest, and a number of idealized geometric descriptions have been proposed. In order to acquire detailed, quantitative, geometric data for aluminum open-cell metal foams, X-ray {mu}CT is employed. The X-ray {mu}CT images are analyzed using specialized software, FoamView Registered-Sign , from which geometric information including strut length and pore shapes are extracted. The X-ray {mu}CT analysis allows comparison of the ideal geometric models to the actual geometric characteristics of the metal foam samples. The results reveal a high variability in ligament length, as well as features supporting the ideal geometry known as the Weaire-Phelan unit cell. The geometric findings provide information useful for improving current models of open-cell metal foam. Applications can range from predicting heat transfer or load failure to predicting liquid retention. Highlights: Black-Right-Pointing-Pointer Aluminum open-cell metal foams are geometrically classified Black-Right-Pointing-Pointer X-ray micro-computed tomography and specialized software are used to gather geometric data Black-Right-Pointing-Pointer The foams are shown to have a high variability in strut length Black-Right-Pointing-Pointer The Weaire-Phelan unit cell is shown to be a better representative of these foams.

  14. 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.

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

    PubMed

    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 x 13 cm(2), 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 microm 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.

  16. Virtual casting of stab wounds in cartilage using micro-computed tomography.

    PubMed

    Pounder, Derrick J; Sim, Louise J

    2011-06-01

    In homicidal stabbings using a serrated knife, stab wounds involving costal cartilage leave striations on the cut surface of the cartilage from the serration points on the blade edge. Class characteristics of the serrated blade can be determined from the striation marks, and individualizing characteristics may be seen also. The traditional method for recording the striation marks involves the pernickety technique of casting with dental impression material. We assessed the potential utility of micro-computed tomography scanning of the stab track as a technique for nondestructive recording of striation patterns and virtual casting of them. Stab tracks in porcine cartilage, produced with a coarsely serrated blade, were scanned with a bench-top micro-computed tomography scanner. The typical irregularly regular striation pattern could be demonstrated, and the images manipulated, using proprietary software to produce a virtual cast. Whether the technology will have sufficient resolution to image not only class characteristic tool marks but also the much finer individualizing tool marks remains to be evaluated, but the technology shows considerable promise.

  17. 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.

  18. Micro-computed tomography assessment of the progression of fracture healing in mice.

    PubMed

    O'Neill, Kevin R; Stutz, Christopher M; Mignemi, Nicholas A; Burns, Michael C; Murry, Matthew R; Nyman, Jeffry S; Schoenecker, Jonathan G

    2012-06-01

    The mouse fracture model is ideal for research into the pathways of healing because of the availability of genetic and transgenic mice and the ability to create cell-specific genetic mutations. While biomechanical tests and histology are available to assess callus integrity and tissue differentiation, respectively, micro-computed tomography (μCT) analysis has increasingly been utilized in fracture studies because it is non-destructive and provides descriptions of the structural and compositional properties of the callus. However, the dynamic changes of μCT properties that occur during healing are not well defined. Thus, the purpose of this study was to determine which μCT properties change with the progression of fracture repair and converge to values similar to unfractured bone in the mouse femur fracture model. A unilateral femur fracture was performed in C57BL/6 mice and intramedullary fixation performed. Fractured and un-fractured contralateral specimens were harvested from groups of mice between 2 and 12 weeks post-fracture. Parameters describing callus based on μCT were obtained, including polar moment of inertia (J), bending moment of inertia (I), total volume (TV), tissue mineral density (TMD), total bone volume fraction (BV/TV), and volumetric bone mineral density (vBMD). For comparison, plain radiographs were used to measure the callus diameter (D) and area (A); and biomechanical properties were evaluated using either three-point bending or torsion. The μCT parameters J, I, TV, and TMD converged toward their respective values of the un-fractured femurs over time, although significant differences existed between the two sides at every time point evaluated (p<0.05). Radiograph measurement D changed with repair progression in similar manner to TV. In contrast, BV/TV and BMD increased and decreased over time with statistical differences between callus and un-fractured bone occurring sporadically. Similarly, none of the biomechanical properties were found

  19. Carbon nanotube based microfocus field emission x-ray source for microcomputed tomography

    SciTech Connect

    Liu Zejian; Yang Guang; Lee, Yueh Z.; Bordelon, David; Lu Jianping; Zhou, Otto

    2006-09-04

    Microcomputed tomography is now widely used for in vivo small animal imaging for cancer studies. Achieving high imaging quality of live objects requires the x-ray source to have both high spatial and temporal resolutions. Preliminary studies have shown that carbon nanotube (CNT) based field emission x-ray source has significant intrinsic advantages over the conventional thermionic x-ray tube including better temporal resolution and programmability. Here we report the design and characterization of a CNT based field emission x-ray source that also affords a high spatial resolution. The device uses modified asymmetric Einzel lenses for electron focusing and an elliptical shaped CNT cathode patterned by photolithography. Stable and small isotropic x-ray focal spot sizes were obtained.

  20. 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.

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

    PubMed

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

    2013-01-01

    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.

  2. 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

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

    PubMed

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

    2013-01-01

    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

  4. 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

  5. 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.

  6. Anatomy of the fundus of the internal acoustic meatus - micro-computed tomography study.

    PubMed

    Kozerska, M; Skrzat, J

    2015-01-01

    The aim of this paper was to present micro-computed tomography (micro-CT) high resolution images of the fundus of internal acoustic meatus (FIAM) and characterise the normal appearance of its singular areas which are places of passage of numerous anatomical structures. By using micro-CT we obtain detailed volume rendering images presenting topography of the FIAM in 3-dimensional (3D) space. We figured out that 3D reconstructions obtained from micro-CT scans can precisely demonstrate all areas of the FIAM (facial nerve area, cochlear area, superior and inferior vestibular areas, singular foramen). Application of this technique allows finding out new anatomical structures like the foramen of the transverse crest, which is not described in literature. Hence, we estimated the size of each area of the FIAM by measuring their minimal and maximal diameter. In the studied material we did not find out any statistically significant difference between mean diameters calculated for infant and adult individuals. PMID:26339817

  7. 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.

  8. 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.

  9. Noninvasive technique for monitoring drug transport through the murine cochlea using micro-computed tomography.

    PubMed

    Haghpanahi, Masoumeh; Gladstone, Miriam B; Zhu, Xiaoxia; Frisina, Robert D; Borkholder, David A

    2013-10-01

    Local delivery of drugs to the inner ear has the potential to treat inner ear disorders including permanent hearing loss or deafness. Current mathematical models describing the pharmacokinetics of drug delivery to the inner ear have been based on large rodent studies with invasive measurements of concentration at few locations within the cochlea. Hence, estimates of clearance and diffusion parameters are based on fitting measured data with limited spatial resolution to a model. To overcome these limitations, we developed a noninvasive imaging technique to monitor and characterize drug delivery inside the mouse cochlea using micro-computed tomography (μCT). To increase the measurement accuracy, we performed a subject-atlas image registration to exploit the information readily available in the atlas image of the mouse cochlea and pass segmentation or labeling information from the atlas to our μCT scans. The approach presented here has the potential to quantify concentrations at any point along fluid-filled scalae of the inner ear. This may permit determination of spatially dependent diffusion and clearance parameters for enhanced models.

  10. 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

  11. 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.

  12. Determining collagen distribution in articular cartilage using contrast-enhanced micro-computed tomography

    PubMed Central

    Nieminen, H.J.; Ylitalo, T.; Karhula, S.; Suuronen, J.-P.; Kauppinen, S.; Serimaa, R.; Hæggström, E.; Pritzker, K.P.H.; Valkealahti, M.; Lehenkari, P.; Finnilä, M.; Saarakkala, S.

    2015-01-01

    Summary Objective Collagen distribution within articular cartilage (AC) is typically evaluated from histological sections, e.g., using collagen staining and light microscopy (LM). Unfortunately, all techniques based on histological sections are time-consuming, destructive, and without extraordinary effort, limited to two dimensions. This study investigates whether phosphotungstic acid (PTA) and phosphomolybdic acid (PMA), two collagen-specific markers and X-ray absorbers, could (1) produce contrast for AC X-ray imaging or (2) be used to detect collagen distribution within AC. Method We labeled equine AC samples with PTA or PMA and imaged them with micro-computed tomography (micro-CT) at pre-defined time points 0, 18, 36, 54, 72, 90, 180, 270 h during staining. The micro-CT image intensity was compared with collagen distributions obtained with a reference technique, i.e., Fourier-transform infrared imaging (FTIRI). The labeling time and contrast agent producing highest association (Pearson correlation, Bland–Altman analysis) between FTIRI collagen distribution and micro-CT -determined PTA distribution was selected for human AC. Results Both, PTA and PMA labeling permitted visualization of AC features using micro-CT in non-calcified cartilage. After labeling the samples for 36 h in PTA, the spatial distribution of X-ray attenuation correlated highly with the collagen distribution determined by FTIRI in both equine (mean ± S.D. of the Pearson correlation coefficients, r = 0.96 ± 0.03, n = 12) and human AC (r = 0.82 ± 0.15, n = 4). Conclusions PTA-induced X-ray attenuation is a potential marker for non-destructive detection of AC collagen distributions in 3D. This approach opens new possibilities in development of non-destructive 3D histopathological techniques for characterization of OA. PMID:26003951

  13. Accurate micro-computed tomography imaging of pore spaces in collagen-based scaffold.

    PubMed

    Zidek, Jan; Vojtova, Lucy; Abdel-Mohsen, A M; Chmelik, Jiri; Zikmund, Tomas; Brtnikova, Jana; Jakubicek, Roman; Zubal, Lukas; Jan, Jiri; Kaiser, Jozef

    2016-06-01

    In this work we have used X-ray micro-computed tomography (μCT) as a method to observe the morphology of 3D porous pure collagen and collagen-composite scaffolds useful in tissue engineering. Two aspects of visualizations were taken into consideration: improvement of the scan and investigation of its sensitivity to the scan parameters. Due to the low material density some parts of collagen scaffolds are invisible in a μCT scan. Therefore, here we present different contrast agents, which increase the contrast of the scanned biopolymeric sample for μCT visualization. The increase of contrast of collagenous scaffolds was performed with ceramic hydroxyapatite microparticles (HAp), silver ions (Ag(+)) and silver nanoparticles (Ag-NPs). Since a relatively small change in imaging parameters (e.g. in 3D volume rendering, threshold value and μCT acquisition conditions) leads to a completely different visualized pattern, we have optimized these parameters to obtain the most realistic picture for visual and qualitative evaluation of the biopolymeric scaffold. Moreover, scaffold images were stereoscopically visualized in order to better see the 3D biopolymer composite scaffold morphology. However, the optimized visualization has some discontinuities in zoomed view, which can be problematic for further analysis of interconnected pores by commonly used numerical methods. Therefore, we applied the locally adaptive method to solve discontinuities issue. The combination of contrast agent and imaging techniques presented in this paper help us to better understand the structure and morphology of the biopolymeric scaffold that is crucial in the design of new biomaterials useful in tissue engineering. PMID:27153826

  14. 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.

  15. 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.

  16. Micro-computed tomography assessment of fracture healing: relationships among callus structure, composition, and mechanical function.

    PubMed

    Morgan, Elise F; Mason, Zachary D; Chien, Karen B; Pfeiffer, Anthony J; Barnes, George L; Einhorn, Thomas A; Gerstenfeld, Louis C

    2009-02-01

    Non-invasive characterization of fracture callus structure and composition may facilitate development of surrogate measures of the regain of mechanical function. As such, quantitative computed tomography- (CT-) based analyses of fracture calluses could enable more reliable clinical assessments of bone healing. Although previous studies have used CT to quantify and predict fracture healing, it is unclear which of the many CT-derived metrics of callus structure and composition are the most predictive of callus mechanical properties. The goal of this study was to identify the changes in fracture callus structure and composition that occur over time and that are most closely related to the regain of mechanical function. Micro-computed tomography (microCT) imaging and torsion testing were performed on murine fracture calluses (n=188) at multiple post-fracture timepoints and under different experimental conditions that alter fracture healing. Total callus volume (TV), mineralized callus volume (BV), callus mineralized volume fraction (BV/TV), bone mineral content (BMC), tissue mineral density (TMD), standard deviation of mineral density (sigma(TMD)), effective polar moment of inertia (J(eff)), torsional strength, and torsional rigidity were quantified. Multivariate statistical analyses, including multivariate analysis of variance, principal components analysis, and stepwise regression were used to identify differences in callus structure and composition among experimental groups and to determine which of the microCT outcome measures were the strongest predictors of mechanical properties. Although calluses varied greatly in the absolute and relative amounts of mineralized tissue (BV, BMC, and BV/TV), differences among timepoints were most strongly associated with changes in tissue mineral density. Torsional strength and rigidity were dependent on mineral density as well as the amount of mineralized tissue: TMD, BV, and sigma(TMD) explained 62% of the variation in

  17. 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

  18. Quantification and Characterization of Radiation-Induced Changes to Mandibular Vascularity using Micro-Computed Tomography

    PubMed Central

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

    2015-01-01

    Objective 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. XRT 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 (micro-CT) technique to attain highly precise quantitative metrics of the vascular tree. Methods Fourteen 400g male Sprague-Dawley rats underwent 35 Gy of fractionated XRT at 7 Gy/day. The animals were euthanized after 28 days and the left ventricle was fixed and injected with Microfil contrast. Left hemimandibles were dissected and scanned using high-resolution micro-CT (18μ voxels). The vessel number, thickness, separation, connectivity and vessel volume fraction were analyzed for the region of interest (ROI), defined to be the volume behind the third molar spanning a total distance of 5.1 mm. Results Stereological analysis and subsequent ANOVA test demonstrated a significant and quantifiable diminution in the irradiated vasculature when compared to control animals. The vessel volume fraction (0.016 vs. 0.032, p≤0.003) and vessel thickness (0.042mm vs. 0.067mm, p≤0.001) were markedly reduced. Interestingly, further analysis demonstrated no significant differences between vessel separation and vessel number. Conclusion The results of our study specifically quantify the corrosive affects of XRT on the vasculature of the mandible. The data from this novel technique goes even further and implies retention of blood vessels, but a degradation of

  19. A microcomputed tomography scanning study of root canal space: changes after the ultrasonic removal of fractured files.

    PubMed

    Madarati, Ahmad A; Qualtrough, Alison J E; Watts, David C

    2009-01-01

    This in vitro study aimed to investigate the effect of ultrasonic removal of endodontic fractured files on tooth structure. Fifty-three canine roots were cleaned and weighed. They were scanned by a microcomputed tomography scanner producing two-dimensional images that were reconstructed into two-dimensional slices, and, finally, the canal volume was measured. In a control group, canals were prepared to F5-size ProTaper (Dentsply Ltd, Surrey, UK). In three experimental groups, F5-fractured files were ultrasonically removed from three root canal locations: coronal, middle, and apical. All roots were reweighed and rescanned. Reconstruction and analysis were performed to remeasure the canal volume. The differences in root mass (weight) and canal volume between before and after treatment were calculated. The highest change increase in canal volume was found when fractured files were removed from the apical part followed by middle and coronal. A positive correlation existed between canal volume and root mass changes. Microcomputed tomography scanning can reliably determine changes in canal volume resulting from fractured-file removal.

  20. 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

  1. A micro-computed tomography technique to study the quality of fibre optics embedded in composite materials.

    PubMed

    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.

  2. 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.

  3. 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.; 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 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

  4. 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.

  5. 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.

  6. 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

  7. 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.

  8. Micro-computed tomography and histomorphometric analysis of human alveolar bone repair induced by laser phototherapy: a pilot study.

    PubMed

    Romão, M M A; Marques, M M; Cortes, A R G; Horliana, A C R T; Moreira, M S; Lascala, C A

    2015-12-01

    Immediate dental implant placement in the molar region is critical, because of the high amount of bone loss and the discrepancy between alveolar crest thickness and the implant platform. Laser phototherapy (LPT) improves bone repair. The aim of this study was to evaluate the human alveolar bone repair 40 days after molar extraction in patients submitted to LPT. Twenty patients were selected for this randomized controlled clinical trial; 10 underwent LPT (laser group) with a GaAlAs diode laser (808 nm, 100 mW, 0.04 cm(2), 75 J/cm(2), 30s per point, 3 J per point, at five points). The control group patients (n=10) were not irradiated. Forty days later, the tissue formed inside the sockets was analyzed by micro-computed tomography and histomorphometry. Data from the two groups were compared with Student's t-test and Pearson's correlation test. The relative bone volume was significantly higher in the laser group (P<0.0001). The control group showed negative correlations (P<0.01) between number and thickness, and between number and separation of trabeculae, and a positive correlation between thickness and separation of trabeculae. The laser group showed a significant negative correlation between the number and thickness of trabeculae (P<0.01). The results suggest that LPT is able to accelerate alveolar bone repair after molar extraction, leading to a more homogeneous trabecular configuration represented by thin and close trabeculae.

  9. 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.

  10. Novel Method to Track Soft Tissue Deformation by Micro-Computed Tomography: Application to the Mitral Valve.

    PubMed

    Pierce, Eric L; Bloodworth, Charles H; Naran, Ajay; Easley, Thomas F; Jensen, Morten O; Yoganathan, Ajit P

    2016-07-01

    Increasing availability of micro-computed tomography (µCT) as a structural imaging gold-standard is bringing unprecedented geometric detail to soft tissue modeling. However, the utility of these advances is severely hindered without analogous enhancement to the associated kinematic detail. To this end, labeling and following discrete points on a tissue across various deformation states is a well-established approach. Still, existing techniques suffer limitations when applied to complex geometries and large deformations and strains. Therefore, we herein developed a non-destructive system for applying fiducial markers (minimum diameter: 500 µm) to soft tissue and tracking them through multiple loading conditions by µCT. Using a novel applicator to minimize adhesive usage, four distinct marker materials were resolvable from both tissue and one another, without image artifacts. No impact on tissue stiffness was observed. µCT addressed accuracy limitations of stereophotogrammetry (inter-method positional error 1.2 ± 0.3 mm, given marker diameter 1.9 ± 0.1 mm). Marker application to ovine mitral valves revealed leaflet Almansi areal strains (45 ± 4%) closely matching literature values, and provided radiographic access to previously inaccessible regions, such as the leaflet coaptation zone. This system may meaningfully support mechanical characterization of numerous tissues or biomaterials, as well as tissue-device interaction studies for regulatory standards purposes. PMID:26553575

  11. A Novel In Vivo Vascular Imaging Approach for Hierarchical Quantification of Vasculature Using Contrast Enhanced Micro-Computed Tomography

    PubMed Central

    Nebuloni, Laura; Kuhn, Gisela A.; Vogel, Johannes; Müller, Ralph

    2014-01-01

    The vasculature of body tissues is continuously subject to remodeling processes originating at the micro-vascular level. The formation of new blood vessels (angiogenesis) is essential for a number of physiological and pathophysiological processes such as tissue regeneration, tumor development and the integration of artificial tissues. There are currently no time-lapsed in vivo imaging techniques providing information on the vascular network at the capillary level in a non-destructive, three-dimensional and high-resolution fashion. This paper presents a novel imaging framework based on contrast enhanced micro-computed tomography (micro-CT) for hierarchical in vivo quantification of blood vessels in mice, ranging from largest to smallest structures. The framework combines for the first time a standard morphometric approach with densitometric analysis. Validation tests showed that the method is precise and robust. Furthermore, the framework is sensitive in detecting different perfusion levels after the implementation of a murine ischemia-reperfusion model. Correlation with both histological data and micro-CT analysis of vascular corrosion casts confirmed accuracy of the method. The newly developed time-lapsed imaging approach shows high potential for in vivo monitoring of a number of different physiological and pathological conditions in angiogenesis and vascular development. PMID:24475146

  12. 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

  13. 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.

  14. 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. PMID:27058023

  15. Comparative microcomputed tomography and histological study of maxillary pneumatization in four species of new world monkeys: the perinatal period.

    PubMed

    Smith, Timothy D; Rossie, James B; Cooper, Gregory M; Schmieg, Robin M; Bonar, Christopher J; Mooney, Mark P; Siegel, Michael I

    2011-03-01

    In anthropoid primates, it has been hypothesized that the magnitude of maxillary sinus growth is influenced by adjacent dental and soft tissue matrices. Relatively, little comparative evidence exists for the perinatal period when secondary pneumatization is at its earliest stages in some primates. Here, dental and midfacial variables were studied in a perinatal sample of four anthropoid primates, including three callitrichines (Leontopithecus, Saguinus, and Callithrix) and Saimiri boliviensis. In the latter species, the maxillary recess (the ontogenetic precursor to a "true" maxillary sinus) does not undergo secondary pneumatization. Using histological methods and micro-computed tomography, midfacial and dental dimensions and radiographic hydroxyapatite density of tooth cusps were measured. The distribution of osteoclasts and osteoblasts was also documented. Kruskal-Wallis's one-way analysis of variance tests indicates significant (P < 0.05) differences among groups for dental and midfacial measurements. In particular, the posterior maxillary dentition is relatively larger and more mineralized in Saimiri compared to the callitrichines. At posterior dental levels, Saimiri has the lowest palatonasal index [interdental (palatal) width/width of the nasal cavity] and highest bizygomatic-interorbital index. Distribution of osteoclasts indicates that the inferomedial surfaces of the orbits are resorptive in perinatal Saimiri, whereas, in all callitrichines, these surfaces are depository. Taken together, these findings suggest that pneumatization in Saimiri is suppressed by an inward growth trajectory of the orbits, relatively large posterior dentition, and a correspondingly compressed nasal region.

  16. 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.

  17. 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

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

    PubMed

    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

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

    PubMed

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

    2015-06-01

    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. PMID:25728683

  20. 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.

  1. Development of a Micro-Computed Tomography-Based Image-Guided Conformal Radiotherapy System for Small Animals

    SciTech Connect

    Zhou Hu; Rodriguez, Manuel; Haak, Fred van den; Nelson, Geoffrey; Jogani, Rahil

    2010-09-01

    Purpose: To report on the physical aspects of a system in which radiotherapy functionality was added to a micro-computed tomography (microCT) scanner, to evaluate the accuracy of this instrument, and to and demonstrate the application of this technology for irradiating tumors growing within the lungs of mice. Methods and Materials: A GE eXplore RS120 microCT scanner was modified by the addition of a two-dimensional subject translation stage and a variable aperture collimator. Quality assurance protocols for these devices, including measurement of translation stage positioning accuracy, collimator aperture accuracy, and collimator alignment with the X-ray beam, were devised. Use of this system for image-guided radiotherapy was assessed by irradiation of a solid water phantom as well as of two mice bearing spontaneous MYC-induced lung tumors. Radiation damage was assessed ex vivo by immunohistochemical detection of {gamma}H2AX foci. Results: The positioning error of the translation stage was found to be <0.05 mm, whereas after alignment of the collimator with the X-ray axis through adjustment of its displacement and rotation, the collimator aperture error was <0.1 mm measured at isocenter. Computed tomography image-guided treatment of a solid water phantom demonstrated target localization accuracy to within 0.1 mm. Gamma-H2AX foci were detected within irradiated lung tumors in mice, with contralateral lung tissue displaying background staining. Conclusions: Addition of radiotherapy functionality to a microCT scanner is an effective means of introducing image-guided radiation treatments into the preclinical setting. This approach has been shown to facilitate small-animal conformal radiotherapy while leveraging existing technology.

  2. 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.

  3. 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. PMID:18362725

  4. 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

  5. 3D tissue-engineered construct analysis via conventional high-resolution microcomputed tomography without X-ray contrast.

    PubMed

    Voronov, Roman S; VanGordon, Samuel B; Shambaugh, Robert L; Papavassiliou, Dimitrios V; Sikavitsas, Vassilios I

    2013-05-01

    As the field of tissue engineering develops, researchers are faced with a large number of degrees of freedom regarding the choice of material, architecture, seeding, and culturing. To evaluate the effectiveness of a tissue-engineered strategy, histology is typically done by physically slicing and staining a construct (crude, time-consuming, and unreliable). However, due to recent advances in high-resolution biomedical imaging, microcomputed tomography (μCT) has arisen as a quick and effective way to evaluate samples, while preserving their structure in the original state. However, a major barrier for using μCT to do histology has been its inability to differentiate between materials with similar X-ray attenuation. Various contrasting strategies (hardware and chemical staining agents) have been proposed to address this problem, but at a cost of additional complexity and limited access. Instead, here we suggest a strategy for how virtual 3D histology in silico can be conducted using conventional μCT, and we provide an illustrative example from bone tissue engineering. The key to our methodology is an implementation of scaffold surface architecture that is ordered in relation to cells and tissue, in concert with straightforward image-processing techniques, to minimize the reliance on contrasting for material segmentation. In the case study reported, μCT was used to image and segment porous poly(lactic acid) nonwoven fiber mesh scaffolds that were seeded dynamically with mesenchymal stem cells and cultured to produce soft tissue and mineralized tissue in a flow perfusion bioreactor using an osteogenic medium. The methodology presented herein paves a new way for tissue engineers to identify and distinguish components of cell/tissue/scaffold constructs to easily and effectively evaluate the tissue-engineering strategies that generate them.

  6. 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. PMID:27430011

  7. 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.

  8. 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.

  9. Fast laboratory-based micro-computed tomography for pore-scale research: Illustrative experiments and perspectives on the future

    NASA Astrophysics Data System (ADS)

    Bultreys, Tom; Boone, Marijn A.; Boone, Matthieu N.; De Schryver, Thomas; Masschaele, Bert; Van Hoorebeke, Luc; Cnudde, Veerle

    2016-09-01

    Over the past decade, the wide-spread implementation of laboratory-based X-ray micro-computed tomography (micro-CT) scanners has revolutionized both the experimental and numerical research on pore-scale transport in geological materials. The availability of these scanners has opened up the possibility to image a rock's pore space in 3D almost routinely to many researchers. While challenges do persist in this field, we treat the next frontier in laboratory-based micro-CT scanning: in-situ, time-resolved imaging of dynamic processes. Extremely fast (even sub-second) micro-CT imaging has become possible at synchrotron facilities over the last few years, however, the restricted accessibility of synchrotrons limits the amount of experiments which can be performed. The much smaller X-ray flux in laboratory-based systems bounds the time resolution which can be attained at these facilities. Nevertheless, progress is being made to improve the quality of measurements performed on the sub-minute time scale. We illustrate this by presenting cutting-edge pore scale experiments visualizing two-phase flow and solute transport in real-time with a lab-based environmental micro-CT set-up. To outline the current state of this young field and its relevance to pore-scale transport research, we critically examine its current bottlenecks and their possible solutions, both on the hardware and the software level. Further developments in laboratory-based, time-resolved imaging could prove greatly beneficial to our understanding of transport behavior in geological materials and to the improvement of pore-scale modeling by providing valuable validation.

  10. 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

  11. 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.

  12. 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

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. 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

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

    NASA Astrophysics Data System (ADS)

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

    2010-01-01

    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 μm 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.

  2. 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.

  3. Structure and micro-computed tomography-based finite element modeling of Toucan beak.

    PubMed

    Seki, Yasuaki; Mackey, Mason; Meyers, Marc A

    2012-05-01

    Bird beaks are one of the most fascinating sandwich composites in nature. Their design is composed of a keratinous integument and a bony foam core. We evaluated the structure and mechanical properties of a Toucan beak to establish structure-property relationships. We revealed the hierarchical structure of the Toucan beak by microscopy techniques. The integument consists of 50 μm polygonal keratin tiles with ~7.5 nm embedded intermediate filaments. The branched intermediate filaments were visualized by TEM tomography techniques. The bony foam core or trabecular bone is a closed-cell foam, which serves as a stiffener for the beak. The tridimensional foam structure was reconstructed by μ-CT scanning to create a model for the finite element analysis (FEA). The mechanical response of the beak foam including trabeculae and cortical shell was measured in tension and compression. We found that Young's modulus is 3 (S.D. 2.2) GPa for the trabeculae and 0.3 (S.D. 0.2) GPa for the cortical shell. After obtaining the material parameters, the deformation and microscopic failure of foam were calculated by FEA. The calculations agree well with the experimental results. PMID:22498278

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

    PubMed

    Santos, L A N; Lopes, L J; 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.

  5. Three Dimensional Imaging of Paraffin Embedded Human Lung Tissue Samples by Micro-Computed Tomography

    PubMed Central

    Scott, Anna E.; Vasilescu, Dragos M.; Seal, Katherine A. D.; Keyes, Samuel D.; Mavrogordato, Mark N.; Hogg, James C.; Sinclair, Ian; Warner, Jane A.; Hackett, Tillie-Louise; Lackie, Peter M.

    2015-01-01

    Background Understanding the three-dimensional (3-D) micro-architecture of lung tissue can provide insights into the pathology of lung disease. Micro computed tomography (µCT) has previously been used to elucidate lung 3D histology and morphometry in fixed samples that have been stained with contrast agents or air inflated and dried. However, non-destructive microstructural 3D imaging of formalin-fixed paraffin embedded (FFPE) tissues would facilitate retrospective analysis of extensive tissue archives of lung FFPE lung samples with linked clinical data. Methods FFPE human lung tissue samples (n = 4) were scanned using a Nikon metrology µCT scanner. Semi-automatic techniques were used to segment the 3D structure of airways and blood vessels. Airspace size (mean linear intercept, Lm) was measured on µCT images and on matched histological sections from the same FFPE samples imaged by light microscopy to validate µCT imaging. Results The µCT imaging protocol provided contrast between tissue and paraffin in FFPE samples (15mm x 7mm). Resolution (voxel size 6.7 µm) in the reconstructed images was sufficient for semi-automatic image segmentation of airways and blood vessels as well as quantitative airspace analysis. The scans were also used to scout for regions of interest, enabling time-efficient preparation of conventional histological sections. The Lm measurements from µCT images were not significantly different to those from matched histological sections. Conclusion We demonstrated how non-destructive imaging of routinely prepared FFPE samples by laboratory µCT can be used to visualize and assess the 3D morphology of the lung including by morphometric analysis. PMID:26030902

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

    PubMed Central

    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 R2 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 (Et) 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 R2 between predicted and experimental strength when compared with uniform Et=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%. PMID:25908967

  7. 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%.

  8. 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.

  9. 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.

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

    PubMed Central

    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

    Background: 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. Materials and Methods: 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. Results: 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. Conclusions: Micro-CT is a promising modality for measuring and staging the IDC. PMID:26730350

  11. 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

  12. 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

  13. 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

  14. 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.

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

    NASA Astrophysics Data System (ADS)

    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 μm 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.

  16. 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. PMID:26648337

  17. 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.

  18. 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.

  19. 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…

  20. 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

  1. Understanding the micro structure of Berea Sandstone by the simultaneous use of micro-computed tomography (micro-CT) and focused ion beam-scanning electron microscopy (FIB-SEM).

    PubMed

    Bera, Bijoyendra; Mitra, Sushanta K; Vick, Douglas

    2011-07-01

    Berea sandstone is the building block for reservoirs containing precious hydrocarbon fuel. In this study, we comprehensively reveal the microstructure of Berea sandstone, which is often treated as a porous material with interconnected micro-pores of 2-5 μm. This has been possible due to the combined application of micro-computed tomography (CT) and focused ion beam (FIB)-scanning electron microscopy (SEM) on a Berea sample. While the use of micro-CT images are common for geological materials, the clubbing and comparison of tomography on Berea with state-of-the-art microstructure imaging techniques like FIB-SEM reveals some unforeseen features of Berea microstructure. In particular, for the first time FIB-SEM has been used to understand the micro-structure of reservoir rock material like Berea sandstone. By using these characterization tools, we are able to show that the micro-pores (less than 30 μm) are absent below the solid material matrix, and that it has small interconnected pores (30-40 μm) and large crater-like voids (100-250 μm) throughout the bulk material. Three-dimensional pore space reconstructions have been prepared from the CT images. Accordingly, characterization of Berea sandstone specimen is performed by calculation of pore-structure volumes and determination of porosity values.

  2. 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…

  3. 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.

  4. Comparison of computed tomography dose reporting software.

    PubMed

    Abdullah, A; Sun, Z; Pongnapang, N; Ng, K-H

    2012-08-01

    Computed tomography (CT) dose reporting software facilitates the estimation of doses to patients undergoing CT examinations. In this study, comparison of three software packages, i.e. CT-Expo (version 1.5, Medizinische Hochschule, Hannover, Germany), ImPACT CT Patients Dosimetry Calculator (version 0.99×, Imaging Performance Assessment on Computed Tomography, www.impactscan.org) and WinDose (version 2.1a, Wellhofer Dosimetry, Schwarzenbruck, Germany), has been made in terms of their calculation algorithm and the results of calculated doses. Estimations were performed for head, chest, abdominal and pelvic examinations based on the protocols recommended by European guidelines using single-slice CT (SSCT) (Siemens Somatom Plus 4, Erlangen, Germany) and multi-slice CT (MSCT) (Siemens Sensation 16, Erlangen, Germany) for software-based female and male phantoms. The results showed that there are some differences in final dose reporting provided by these software packages. There are deviations of effective doses produced by these software packages. Percentages of coefficient of variance range from 3.3 to 23.4 % in SSCT and from 10.6 to 43.8 % in MSCT. It is important that researchers state the name of the software that is used to estimate the various CT dose quantities. Users must also understand the equivalent terminologies between the information obtained from the CT console and the software packages in order to use the software correctly.

  5. Micro-computed tomography: a method for the non-destructive evaluation of the three-dimensional structure of biological specimens.

    PubMed

    Stauber, Martin; Müller, Ralph

    2008-01-01

    The large increase in interest in micro-computed tomography (micro-CT) over the last decade reflects the+ need for a method able to non-destructively visualize the internal three-dimensional structure of an object. Thereby, the real beauty of computed tomography lies in the fact that it is available for a large range of nominal resolutions, which allows hierarchical imaging from whole bodies down to the tissue level. Although micro-CT is currently mainly used for imaging of hard tissue (i.e., bone and tooth), future developments might also allow high soft tissue contrast either using appropriate contrast agents or x-ray contrast mechanisms. This chapter aims to review the steps necessary for a successful micro-CT measurement. Although the actual measurement is often machine dependent, the chapter does not describe a specific system but rather lists all steps that eventually have to be considered to set up a measurement, run the measurement, process the image data, and get morphometric indices as a result. The chapter provides an easy understandable manual that should allow newcomers to perform successful measurements and hence to best profit from this powerful technique.

  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. 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. PMID:26580735

  9. 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.

  10. 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.

  11. 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.

  12. Bone dynamics in the upward direction after a maxillary sinus floor elevation procedure: serial segmentation using synchrotron radiation micro-computed tomography

    PubMed Central

    Seo, Seung-Jun; Bark, Chung Wung; Lim, Jae-Hong; Kim, Yong-Gun

    2015-01-01

    Objective Maxillary sinus floor augmentation has been shown to be the most predictable surgical technique for enhancing the bone volume in the posterior area of the maxilla. The purpose of this study was to analyze the serial slice image segmentation of newly formed bone and bone substitutes after sinus floor elevation using synchrotron radiation X-ray micro-computed tomography (SR-μCT). Materials and methods Bone biopsy specimens were collected after 6 months of sinus floor augmentation. From the six bone biopsy specimens, the cross-sectional images at every 8 μm along the apical direction from the inferior border using serial segmentation from three-dimensional reconstructed X-ray images were analyzed. The amount of new bone and bone substitutes were measured at each slicing image (300–430 images per specimen). Results The bone dynamics between the new bone and bone substitutes along the inferior–superior direction in humans after maxillary sinus floor elevation (MSFE) were analyzed using the whole sample region. Although these observations suggest that the specimens are structurally inhomogeneous, sinus floor elevation was confirmed to be a reliable surgical procedure for increasing the amount of bone. Conclusion SR-μCT is highly effective for obtaining high-resolution images. An analysis of biological specimens using SR-μCT is quite reliable and this technique will be an important tool in the wide field of tissue engineering. PMID:26347146

  13. Estimation of an early meaningful time point of bone parameter changes in application to an osteoporotic rat model with in vivo microcomputed tomography measurements.

    PubMed

    Keiler, Annekathrin Martina; Zierau, Oliver; Vollmer, Günter; Scharnweber, Dieter; Bernhardt, Ricardo

    2012-07-01

    The commonly used preclinical animal model of postmenopausal osteoporosis is the mature ovariectomized rat, whereby cessation of ovarian oestrogen production consequently results in bone volume reduction. The study aim was to precisely define the time course of structural changes resulting from ovariectomy and thereby reduce the time animals have to be treated to judge the effects of osteoporosis treatment. For this purpose, we assessed architectural changes by microcomputed tomography (μCT) during 10 weeks following ovariectomy or sham surgery at two-week intervals. Moreover, the trabecular microarchitecture of the lumbar vertebrae was assessed after necropsy. Besides this, serum biomarkers of bone turnover were determined. These data were in a new approach additionally correlated to femur mRNA expression profiles. We selected the osteoblast marker genes osteocalcin and type I collagen as well as the two osteoclast marker genes cathepsin k and tartrate-resistant acid phosphatase 5. The gene expression analysis suggested an activation of osteoblasts as well as octeoclasts. The significantly induced serum levels of osteocalcin and collagen degradation fragments also revealed this higher rate of bone turnover. Our results indicate that as soon as four weeks after ovariectomy the bone volume fraction exhibited a decline of 30% and 50% of the connectivity density. In addition, significant decreases of trabecular number and thickness as well as of the bone volume fraction were only observed in vertebrae of ovariectomized animals. Interestingly, changes of trabecular morphology were also found in the sham animals as a consequence of senescence.

  14. 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

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

    PubMed

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

    2015-11-01

    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.

  16. 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. PMID:27041355

  17. 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.

  18. 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

    2015-07-01

    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.

  19. Micro-Computed Tomography-Based Three-Dimensional Kinematic Analysis During Lateral Bending for Spinal Fusion Assessment in a Rat Posterolateral Lumbar Fusion Model

    PubMed Central

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

    2014-01-01

    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. PMID:24199634

  20. Fracture healing in mice lacking Pten in osteoblasts: a micro-computed tomography image-based analysis of the mechanical properties of the femur.

    PubMed

    Collins, Caitlyn J; Vivanco, Juan F; Sokn, Scott A; Williams, Bart O; Burgers, Travis A; Ploeg, Heidi-Lynn

    2015-01-21

    In the United States, approximately eight million osseous fractures are reported annually, of which 5-10% fail to create a bony union. Osteoblast-specific deletion of the gene Pten in mice has been found to stimulate bone growth and accelerate fracture healing. Healing rates at four weeks increased in femurs from Pten osteoblast conditional knock-out mice (Pten-CKO) compared to wild-type mice (WT) of the same genetic strain as measured by an increase in mechanical stiffness and failure load in four-point bending tests. Preceding mechanical testing, each femur was imaged using a Skyscan 1172 micro-computed tomography (μCT) scanner (Skyscan, Kontich, Belgium). The present study used µCT image-based analysis to test the hypothesis that the increased femoral fracture force and stiffness in Pten-CKO were due to greater section properties with the same effective material properties as that of the WT. The second moment of area and section modulus were computed in ImageJ 1.46 (National Institutes of Health) and used to predict the effective flexural modulus and the stress at failure for fourteen pairs of intact and callus WT and twelve pairs of intact and callus Pten-CKO femurs. For callus and intact femurs, the failure stress and tissue mineral density of the Pten-CKO and WT were not different; however, the section properties of the Pten-CKO were more than twice as large 28 days post-fracture. It was therefore concluded, when the gene Pten was conditionally knocked-out in osteoblasts, the resulting increased bending stiffness and force to fracture were due to increased section properties.

  1. 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.

  2. 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. PMID:23306857

  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. PMID:27249559

  4. 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.

  5. 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

  6. 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

  7. Characterisation of density distributions in roller-compacted ribbons using micro-indentation and X-ray micro-computed tomography.

    PubMed

    Miguélez-Morán, Andres M; Wu, Chuan-Yu; Dong, Hanshan; Seville, Jonathan P K

    2009-05-01

    Roller compaction is one stage in a dry granulation process to produce free flowing granules. Its proper understanding is essential in optimising manufacturing efficiency and product quality. Roller compaction produces a compacted strip or "ribbon", which is then milled to produce granules. For a given milling condition, the density distribution in the ribbons determines the properties of the granules (particularly their size distribution and strength). Therefore, knowing the density distributions in the ribbons is very important in improving the effectiveness of the roller compaction process and the quality of the granules produced. In this paper, the density distribution in roller-compacted ribbons of microcrystalline cellulose (Avicel PH102) has been examined using three different techniques: (1) sectioning; (2) micro-indentation and (3) X-ray micro-computed tomography. It has been shown that with proper calibration all three techniques can essentially produce the same results, but with a different degree of resolution (scale of scrutiny). In addition, the influence of process conditions, such as roll gap, roll speed and the presence or absence of lubrication, on the ribbon density distributions has also been investigated. Flow into the press is often constrained by the presence of "cheek plates", which prevent lateral powder movement. In this type of arrangement, it is found that non-uniform powder feeding occurs in the compaction region, induced by the friction between the powder and the cheek plates; as a result, the densities in the middle of the ribbon width are generally higher than those close to the edges. It has also been shown that higher average ribbon densities are obtained when the roll gap, roll speed, or the friction between the powder and the side cheek plates is reduced.

  8. 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.

  9. Fracture Healing in Mice Lacking Pten in Osteoblasts: A Micro-Computed Tomography Image-Based Analysis of the Mechanical Properties of the Femur

    PubMed Central

    Collins, Caitlyn J.; Vivanco, Juan; Sokn, Scott; Williams, Bart O.; Burgers, Travis A.; Ploeg, Heidi-Lynn

    2014-01-01

    In the United States, approximately 8 million osseous fractures are reported annually, of which 5-10% fail to create a bony union. Osteoblast-specific deletion of the gene Pten in mice has been found to stimulate bone growth and accelerate fracture healing. Healing rates at four weeks increased in femurs from Pten osteoblast conditional knock-out mice (Pten-CKO) compared to wild-type mice (WT) of the same genetic strain as measured by an increase in mechanical stiffness and failure load in four-point bending tests. Preceding mechanical testing, each femur was imaged using a Skyscan 1172 micro-computed tomography (μCT) scanner (Skyscan, Kontich, Belgium). The present study used μCT image-based analysis to test the hypothesis that the increased femoral fracture force and stiffness in Pten-CKO were due to greater section properties with the same effective material properties as that of the WT. The second moment of area and section modulus were computed in ImageJ 1.46 (National Institutes of Health) and used to predict the effective flexural modulus and the stress at failure for fourteen pairs of intact and callus WT and twelve pairs of intact and callus Pten-CKO femurs. For callus and intact femurs, the failure stress and tissue mineral density of the Pten-CKO and WT were not different; however, the section properties of the Pten-CKO were more than twice as large 28 days post-fracture. It was therefore concluded, when the gene Pten was conditionally knocked-out in osteoblasts, the resulting increased bending stiffness and force to fracture were due to increased section properties. PMID:25498366

  10. Experimental Fusion of Contrast Enhanced High-Field Magnetic Resonance Imaging and High-Resolution Micro-Computed Tomography in Imaging the Mouse Inner Ear

    PubMed Central

    Counter, S. Allen; Damberg, Peter; Aski, Sahar Nikkhou; Nagy, Kálmán; Berglin, Cecilia Engmér; Laurell, Göran

    2015-01-01

    Objective: Imaging cochlear, vestibular, and 8th cranial nerve abnormalities remains a challenge. In this study, the membranous and osseous labyrinths of the wild type mouse inner ear were examined using volumetric data from ultra high-field magnetic resonance imaging (MRI) with gadolinium contrast at 9.4 Tesla and high-resolution micro-computed tomography (µCT) to visualize the scalae and vestibular apparatus, and to establish imaging protocols and parameters for comparative analysis of the normal and mutant mouse inner ear. Methods: For in vivo MRI acquisition, animals were placed in a Milleped coil situated in the isocenter of a horizontal 9.4 T Varian magnet. For µCT examination, cone beam scans were performed ex vivo following MRI using the µCT component of a nanoScan PET/CT in vivo scanner. Results: The fusion of Gd enhanced high field MRI and high-resolution µCT scans revealed the dynamic membranous labyrinth of the perilymphatic fluid filled scala tympani and scala vestibule of the cochlea, and semicircular canals of the vestibular apparatus, within the µCT visualized contours of the contiguous osseous labyrinth. The ex vivo µCT segmentation revealed the surface contours and structural morphology of each cochlea turn and the semicircular canals in 3 planes. Conclusions: The fusion of ultra high-field MRI and high-resolution µCT imaging techniques were complementary, and provided high-resolution dynamic and static visualization of the complex morphological features of the normal mouse inner ear structures, which may offer a valuable approach for the investigation of cochlear and vestibular abnormalities that are associated with birth defects related to genetic inner ear disorders in humans. PMID:26401173

  11. A comparative study of the effects of two nickel-titanium preparation techniques on root canal geometry assessed by microcomputed tomography.

    PubMed

    Loizides, Alexios L; Kakavetsos, Vasilios D; Tzanetakis, Giorgos N; Kontakiotis, Evangelos G; Eliades, George

    2007-12-01

    The present study was conducted with the aim of evaluating and comparing the effects of a new Hero group (Endoflare, Hero-shaper, and Hero-apical; Micro-Mega, Besancon, France) and Protaper Ni-Ti rotary instruments (Dentsply/Maillefer, Ballaigues, Switzerland) on root canal geometry in extracted human teeth using microcomputed tomography (muCT). Twenty-two mesial root canals of mandibular first molars were randomly divided into two groups. Canals were scanned before and after preparation with both systems. Cross-sectional images of each canal were obtained at 2-mm intervals. Differences in canal roundness, cross-sectional area, perimeter of each canal before and after instrumentation, and the extent of root canal transportation were calculated using image analysis software. There was no difference between the two rotary systems in regards to working time. Both systems create a similar round shape after instrumentation regardless of the initial root canal's shape. The Hero instruments showed a greater cutting efficiency compared with the ProTaper at the levels of 8 mm, 6 mm, and 4 mm but not at the level of 2 mm. On the other hand, the ProTaper seems to have a similar cutting efficiency at all levels. However, the ProTaper showed a tendency toward apical transportation. Under the conditions of the present study, both preparation techniques prepared the canals rapidly with a sufficient round shape. Despite that, it seems that there is a great potential for the improvement of shaping ability of rotary instruments. Hybrid instrumentation techniques should be evaluated by future studies in order to provide better results regarding the shaping ability of rotary instruments. PMID:18037058

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

    PubMed

    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.

  13. 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.

  14. 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

  15. Micro-computed tomography of pulmonary fibrosis in mice induced by adenoviral gene transfer of biologically active transforming growth factor-β1

    PubMed Central

    2010-01-01

    Background Micro-computed tomography (micro-CT) is a novel tool for monitoring acute and chronic disease states in small laboratory animals. Its value for assessing progressive lung fibrosis in mice has not been reported so far. Here we examined the importance of in vivo micro-CT as non-invasive tool to assess progression of pulmonary fibrosis in mice over time. Methods Pulmonary fibrosis was induced in mice by intratracheal delivery of an adenoviral gene vector encoding biologically active TGF-ß1 (AdTGF-ß1). Respiratory gated and ungated micro-CT scans were performed at 1, 2, 3, and 4 weeks post pulmonary adenoviral gene or control vector delivery, and were then correlated with respective histopathology-based Ashcroft scoring of pulmonary fibrosis in mice. Visual assessment of image quality and consolidation was performed by 3 observers and a semi-automated quantification algorithm was applied to quantify aerated pulmonary volume as an inverse surrogate marker for pulmonary fibrosis. Results We found a significant correlation between classical Ashcroft scoring and micro-CT assessment using both visual assessment and the semi-automated quantification algorithm. Pulmonary fibrosis could be clearly detected in micro-CT, image quality values were higher for respiratory gated exams, although differences were not significant. For assessment of fibrosis no significant difference between respiratory gated and ungated exams was observed. Conclusions Together, we show that micro-CT is a powerful tool to assess pulmonary fibrosis in mice, using both visual assessment and semi-automated quantification algorithms. These data may be important in view of pre-clinical pharmacologic interventions for the treatment of lung fibrosis in small laboratory animals. PMID:21176193

  16. 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. PMID:24797662

  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. Microcomputed tomographic comparison of posterior composite resin restorative techniques: sonicated bulk fill versus incremental fill.

    PubMed

    Jarisch, Justin; Lien, Wen; Guevara, Peter H; Greenwood, William J; Dunn, William J

    2016-01-01

    Sonication technology has recently been touted to decrease composite viscosity during delivery and may allow better cavity preparation adaptation and minimize voids. The purpose of this investigation was to evaluate the difference between conventional, hand-placed, incremental application of a standard hybrid resin-based composite (RBC) and sonicated application of a bulk-fill RBC in box-type and cylindrical cavity preparations. Experimental restorations were fabricated using molds of box-type or cylindrical preparations. For bulk-filled specimens, a single compule of bulk-fill composite was dispensed with a sonic handpiece. The conventional hybrid material was placed in 3 increments (2 mm, 2 mm, and 1 mm). Microfocus x-ray computed tomography was used to analyze voids for percentage and total volume porosity as well as number of actual pores. An analysis of variance indicated that RBC restorations that were applied to cylindrical cavities using a sonicated bulk-filled application method exhibited significantly less porosity (1.42%; P < 0.001) than incrementally placed cylindrical restorations (2.87%); sonicated bulk-filled, cube-shaped restorations (3.12%); and incrementally placed cube-shaped restorations (5.16%). When the groups were subcategorized into the specific characteristics of shape (cube vs cylinder) and application method (bulk vs incremental), the cylindrical group, which included both bulk-filled and incrementally placed specimens, demonstrated significantly less porosity (2.00%; P < 0.001) than other groups. Restorations that were incrementally placed into cube-shaped cavities produced the largest amount of porosity. PMID:27599276

  19. Quality of different gutta-percha techniques when filling experimental internal resorptive cavities: a micro-computed tomography study.

    PubMed

    Keles, Ali; Ahmetoglu, Fuat; Uzun, Ismail

    2014-12-01

    The purpose of this ex vivo study was to determine the quality of root fillings in experimental internal resorptive cavities filled using cold lateral condensation (CLC), vertical condensation and Thermafil techniques. Forty-five extracted maxillary canine teeth were selected. After root canal instrumentation, the roots were sectioned horizontally and experimental internal resorption cavities were prepared. The root sections were re-approximated with a luting agent and randomly assigned to three groups (n = 15) to be filled using CLC, vertical condensation and Thermafil, respectively. Assessment of obturation quality in the internal resorptive cavity was performed using a desktop X-ray micro focus computed tomography scanner, and the percentage of gutta-percha (GP), sealer and voiding was calculated for each specimen. Data were statistically analysed using non-parametric tests, with P < 0.05 denoting a statistically significant difference. Vertical condensation filled 96.25 ± 8.31% of the total artificial cavity, and was superior to CLC (63.20 ± 16.87%) and Thermafil (59.26 ± 18.47%). The mean percentage of voids was 3.75 ± 8.31% in the vertical condensation group, 37.09 ± 17.13% in the CLC group and 41.06 ± 18.60% in the Thermafil group. We conclude that obturation of experimental resorption cavities is significantly better when using vertical condensation than when using other GP-based techniques.

  20. Internal structures of scaffold-free 3D cell cultures visualized by synchrotron radiation-based micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Saldamli, Belma; Herzen, Julia; Beckmann, Felix; Tübel, Jutta; Schauwecker, Johannes; Burgkart, Rainer; Jürgens, Philipp; Zeilhofer, Hans-Florian; Sader, Robert; Müller, Bert

    2008-08-01

    Recently the importance of the third dimension in cell biology has been better understood, resulting in a re-orientation towards three-dimensional (3D) cultivation. Yet adequate tools for their morphological characterization have to be established. Synchrotron radiation-based micro computed tomography (SRμCT) allows visualizing such biological systems with almost isotropic micrometer resolution, non-destructively. We have applied SRμCT for studying the internal morphology of human osteoblast-derived, scaffold-free 3D cultures, termed histoids. Primary human osteoblasts, isolated from femoral neck spongy bone, were grown as 2D culture in non-mineralizing osteogenic medium until a rather thick, multi-cellular membrane was formed. This delicate system was intentionally released to randomly fold itself. The folded cell cultures were grown to histoids of cubic milli- or centimeter size in various combinations of mineralizing and non-mineralizing osteogenic medium for a total period of minimum 56 weeks. The SRμCT-measurements were performed in the absorption contrast mode at the beamlines BW 2 and W 2 (HASYLAB at DESY, Hamburg, Germany), operated by the GKSS-Research Center. To investigate the entire volume of interest several scans were performed under identical conditions and registered to obtain one single dataset of each sample. The histoids grown under different conditions exhibit similar external morphology of globular or ovoid shape. The SRμCT-examination revealed the distinctly different morphological structures inside the histoids. One obtains details of the histoids that permit to identify and select the most promising slices for subsequent histological characterization.

  1. 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.

  2. 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

  3. Quantification of osseointegration of plasma-polymer coated titanium alloyed implants by means of microcomputed tomography versus histomorphometry.

    PubMed

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

    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.

  4. 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

  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. 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

  7. 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.

  8. 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

  9. 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

  10. 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.

  11. 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…

  12. 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)

  13. Microcomputer Applications in Agriculture.

    ERIC Educational Resources Information Center

    Hilgenberg, Gene; And Others

    This curriculum guide is intended to assist persons teaching a course in microcomputer applications in agriculture. (These applications are designed to be used on Apple IIe or TRS-80 microcomputers.) Addressed in the individual units of instruction are the following topics: microcomputer operating procedures; procedures for evaluating and…

  14. 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.

  15. Leeches of the genus Helobdella (Clitellata: Hirudinida) from São Paulo, Brazil with descriptions of two new species using micro-computed tomography and a new record of Barbronia weberi (Blanchard 1897).

    PubMed

    Iwama, Rafael Eiji; Arruda, Eliane Pintor

    2016-01-01

    Leeches are an important group of macroinvertebrates found in the benthic zone of rivers, streams, lakes and ponds. Despite their ecological importance and potential as bioindicators, little is known about the diversity of leeches in Brazil, where only a few sporadic studies have been performed. Six locations in the region of Sorocaba, in the state of São Paulo, were sampled in order to study the diversity of predatory leeches. Besides traditional dissections, micro-computed tomography was used to access the internal morphology of the new species Helobdella chaviensis n. sp. and Helobdella schlenzae n. sp. Four additional native species were found and redescribed using traditional techniques. The invasive species Barbronia weberi (Blanchard 1897) was reported in the Tietê River for the first time. PMID:27470865

  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 explained,…

  17. 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…

  18. 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)

  19. Miracles, Microcomputers, and Librarians.

    ERIC Educational Resources Information Center

    Swanson, Don R.

    1982-01-01

    Describes potential uses of microcomputers in library education and library automation based upon experiences with a four-user Altos ACS8000 microcomputer at the University of Chicago Graduate Library School. Word processing, training in online information retrieval using MIRABILIS (Microsystem for Interactive Bibliographic Searching), and…

  20. Microcomputers and Literacy.

    ERIC Educational Resources Information Center

    Grice, R. D.

    1986-01-01

    The nature of literacy associated with the widely used new medium of microcomputers has not been fully exploited by schools to foster development of literacy programs. Microcomputer applications need integration with classroom activities where students construct language meaning. (19 references) (CJH)

  1. Instructional Microcomputer Report.

    ERIC Educational Resources Information Center

    Black, B. R.

    Intended to aid teachers, administrators, and interested parents by informing them about the state of the educational microcomputer market, this report is meant to be a guide to school districts in the acquisition and maintenance of microcomputers and related instructional materials. Trends in educational computing technology are noted in relation…

  2. 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…

  3. 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.

  4. 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)

  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. PMID:26008768

  6. Use of Micro-Computed Tomography to Nondestructively Characterize Biomineral Coatings on Solid Freeform Fabricated Poly (L-Lactic Acid) and Poly (ɛ-Caprolactone) Scaffolds In Vitro and In Vivo

    PubMed Central

    Saito, Eiji; Suarez-Gonzalez, Darilis; Rao, Rameshwar R.; Stegemann, Jan P.; Murphy, William L.

    2013-01-01

    Biomineral coatings have been extensively used to enhance the osteoconductivity of polymeric scaffolds. Numerous porous scaffolds have previously been coated with a bone-like apatite mineral through incubation in simulated body fluid (SBF). However, characterization of the mineral layer formed on scaffolds, including the amount of mineral within the scaffolds, often requires destructive methods. We have developed a method using micro-computed tomography (μ-CT) scanning to nondestructively quantify the amount of mineral in vitro and in vivo on biodegradable scaffolds made of poly (L-lactic acid) (PLLA) and poly (ɛ-caprolactone) (PCL). PLLA and PCL scaffolds were fabricated using an indirect solid freeform fabrication (SFF) technique to achieve orthogonally interconnected pore architectures. Biomineral coatings were formed on the fabricated PLLA and PCL scaffolds after incubation in modified SBF (mSBF). Scanning electron microscopy and X-ray diffraction confirmed the formation of an apatite-like mineral. The scaffolds were implanted into mouse ectopic sites for 3 and 10 weeks. The presence of a biomineral coating within the porous scaffolds was confirmed through plastic embedding and μ-CT techniques. Tissue mineral content (TMC) and volume of mineral on the scaffold surfaces detected by μ-CT had a strong correlation with the amount of calcium measured by the orthocresolphthalein complex-one (OCPC) method before and after implantation. There was a strong correlation between OCPC pre- and postimplantation and μ-CT measured TMC (R2=0.96 preimplant; R2=0.90 postimplant) and mineral volume (R2=0.96 preimplant; R2=0.89 postimplant). The μ-CT technique showed increases in mineral following implantation, suggesting that μ-CT can be used to nondestructively determine the amount of calcium on coated scaffolds. PMID:23134479

  7. 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.

  8. 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. PMID:25303146

  9. 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…

  10. 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.

  11. 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

  12. 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

  13. 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

    Schmitt, Michael; Uhl, Gabriele

    2015-01-01

    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

  14. Microcomputers in the Laboratory.

    ERIC Educational Resources Information Center

    Rafert, Bruce; Nicklin, R. C.

    1982-01-01

    A one-semester hour laboratory course introduced junior and senior physics majors to assembly language programing and to interfacing KIM-1 microcomputer to experiments. A general purpose interface to a standard breadboard was developed. Course details, apparatus, and some interfacing projects are given. (Author/SK)

  15. Microcomputer Applications Specialist.

    ERIC Educational Resources Information Center

    Ohio State Univ., Columbus. Center on Education and Training for Employment.

    This publication contains 16 subjects appropriate for use in a competency list for the occupation of microcomputer applications specialist, 1 of 12 occupations within the business/computer technologies cluster. Each unit consists of a number of competencies; a list of competency builders is provided for each competency. Titles of the 16 units are…

  16. Microcomputer Controlled Experiments.

    ERIC Educational Resources Information Center

    Kirkman, John; Knaggs, David

    1982-01-01

    Describes a microcomputer-controlled system which determines the current/voltage characteristics of a resistor, lamp, and diode, detailing system elements, construction, and providing printout of the program developed to provide control and arithmetic functions necessary to complete the experiment. (SK)

  17. 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,…

  18. 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…

  19. A new microhylid frog, genus Rhombophryne, from northeastern Madagascar, and a re-description of R. serratopalpebrosa using micro-computed tomography.

    PubMed

    Scherz, Mark D; Ruthensteiner, Bernhard; Vences, Miguel; Glaw, Frank

    2014-01-01

    The rainforests of the Marojejy massif in northern Madagascar are a well-known hotspot of amphibian species diversity and endemism. In the present paper, we re-describe Rhombophryne serratopalpebrosa (Guibé 1975), a cophyline microhylid frog from high altitude on this massif, based on a re-examination of its holotype, and describe Rhombophryne vaventy sp. nov. using characters of external morphology and osteology, illustrated by pdf-embedded comparative 3D models of their skeletons. Rhombophryne serratopalpebrosa differs from R. vaventy sp. nov. by smaller size (28 mm snout-vent length vs. 52.9 mm), skin texture (granular vs. rough and tubercular skin respectively), supratympanic fold shape (strong, long and straight reaching the eye vs. curved and not extending anteriorly beyond the tympanum), relative tympanum diameter (78% vs. 41% of eye diameter), shape of the postchoanal prevomerine palate, shape of the footplate of the columella, length of prepollex, and by other subtle osteological features. Morphological comparisons suggest that a specimen from Ambolokopatrika assigned to R. serratopalpebrosa in previous genetic studies might belong to yet another undescribed species, closely related to R. vaventy sp. nov., whereas DNA sequences of the topotypic R. serratopalpebrosa remain unknown. We therefore emphasise the need for collecting additional material from high altitudes of the Marojejy massif to understand the systematics, as well as the natural history, of this poorly known species. For the new species described herein, we propose a Red List threat status of Vulnerable, in line with other Marojejy endemics from a similar altitude.  PMID:25283290

  20. Microcomputers and astronomical navigation.

    NASA Astrophysics Data System (ADS)

    Robin-Jouan, Y.

    1996-04-01

    Experienced navigators remember ancient astronomical navigation and its limitations. Using microcomputers in small packages and selecting up-to-date efficient methods will overcome many of these limitations. Both features lead to focus on observations, and encourage an increase in their numbers. With no intention of competing with satellite navigation, sextant navigation in the open sea can then be accessed again by anybody. It can be considered for demonstrative use or as a complement to the GPS.

  1. Application of in vivo micro-computed tomography in the temporal characterisation of subchondral bone architecture in a rat model of low-dose monosodium iodoacetate-induced osteoarthritis

    PubMed Central

    2011-01-01

    Introduction Osteoarthritis (OA) is a complex, multifactorial joint disease affecting both the cartilage and the subchondral bone. Animal models of OA aid in the understanding of the pathogenesis of OA and testing suitable drugs for OA treatment. In this study we characterized the temporal changes in the tibial subchondral bone architecture in a rat model of low-dose monosodium iodoacetate (MIA)-induced OA using in vivo micro-computed tomography (CT). Methods Male Wistar rats received a single intra-articular injection of low-dose MIA (0.2 mg) in the right knee joint and sterile saline in the left knee joint. The animals were scanned in vivo by micro-CT at two, six, and ten weeks post-injection, analogous to early, intermediate, and advanced stages of OA, to assess architectural changes in the tibial subchondral bone. The articular cartilage changes in the tibiae were assessed macroscopically and histologically at ten weeks post-injection. Results Interestingly, tibiae of the MIA-injected knees showed significant bone loss at two weeks, followed by increased trabecular thickness and separation at six and ten weeks. The trabecular number was decreased at all time points compared to control tibiae. The tibial subchondral plate thickness of the MIA-injected knee was increased at two and six weeks and the plate porosity was increased at all time points compared to control. At ten weeks, histology revealed loss of proteoglycans, chondrocyte necrosis, chondrocyte clusters, cartilage fibrillation, and delamination in the MIA-injected tibiae, whereas the control tibiae showed no changes. Micro-CT images and histology showed the presence of subchondral bone sclerosis, cysts, and osteophytes. Conclusions These findings demonstrate that the low-dose MIA rat model closely mimics the pathological features of progressive human OA. The low-dose MIA rat model is therefore suitable to study the effect of therapeutic drugs on cartilage and bone in a non-trauma model of OA. In vivo

  2. 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.

  3. A comparison between abdominal ultrasonography and computed tomography.

    PubMed

    Becker, H; Pienaar, G J

    1980-06-28

    Computed tomography (CT) and ultrasonography are based on entirely different physical principles. In the abdomen the two techniques have similar diagnostic applications. Whereas CT is in many instances more informative, it is also a more time-consuming and much more costly procedure. For clinicians who practise in areas where these techniques are available, this article may be useful as a quick guide to the choice of procedure.

  4. 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…

  5. 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…

  6. Microcomputers and the Classroom Order.

    ERIC Educational Resources Information Center

    Olson, John K.

    A preliminary case study used repertory grid and stimulated recall techniques to examine how teachers make sense of the impact of microcomputers on their work. Emphasis was on how teachers construe their classroom influence in relation to the actual use of microcomputers and to idealizations of their use. A version of the Kelly (1955) repgrid was…

  7. Conference Abstracts: Microcomputers in Education.

    ERIC Educational Resources Information Center

    Baird, William E.

    1985-01-01

    Provides abstracts of five papers presented at the Fourth Annual Microcomputers in Education Conference. Papers considered microcomputers in science laboratories, Apple II Plus/e computer-assisted instruction in chemistry, computer solutions for space mechanics concerns, computer applications to problem solving and hypothesis testing, and…

  8. 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.

  9. Comparison of micro-computerized tomography and cone-beam computerized tomography in the detection of accessory canals in primary molars

    PubMed Central

    Kamburoğlu, Kıvanç; Tatar, İlkan; Arıkan, Volkan; Çelik, Hakan Hamdi; Yüksel, Selcen; Özen, Tuncer

    2015-01-01

    Purpose This study was performed to compare the accuracy of micro-computed tomography (CT) and cone-beam computed tomography (CBCT) in detecting accessory canals in primary molars. Materials and Methods Forty-one extracted human primary first and second molars were embedded in wax blocks and scanned using micro-CT and CBCT. After the images were taken, the samples were processed using a clearing technique and examined under a stereomicroscope in order to establish the gold standard for this study. The specimens were classified into three groups: maxillary molars, mandibular molars with three canals, and mandibular molars with four canals. Differences between the gold standard and the observations made using the imaging methods were calculated using Spearman's rho correlation coefficient test. Results The presence of accessory canals in micro-CT images of maxillary and mandibular root canals showed a statistically significant correlation with the stereomicroscopic images used as a gold standard. No statistically significant correlation was found between the CBCT findings and the stereomicroscopic images. Conclusion Although micro-CT is not suitable for clinical use, it provides more detailed information about minor anatomical structures. However, CBCT is convenient for clinical use but may not be capable of adequately analyzing the internal anatomy of primary teeth. PMID:26730367

  10. Quantum state tomography of a single qubit: comparison of methods

    NASA Astrophysics Data System (ADS)

    Schmied, Roman

    2016-10-01

    The tomographic reconstruction of the state of a quantum-mechanical system is an essential component in the development of quantum technologies. We present an overview of different tomographic methods for determining the quantum-mechanical density matrix of a single qubit: (scaled) direct inversion, maximum likelihood estimation (MLE), minimum Fisher information distance and Bayesian mean estimation (BME). We discuss the different prior densities in the space of density matrices, on which both MLE and BME depend, as well as ways of including experimental errors and of estimating tomography errors. As a measure of the accuracy of these methods, we average the trace distance between a given density matrix and the tomographic density matrices it can give rise to through experimental measurements. We find that the BME provides the most accurate estimate of the density matrix, and suggest using either the pure-state prior, if the system is known to be in a rather pure state, or the Bures prior if any state is possible. The MLE is found to be slightly less accurate. We comment on the extrapolation of these results to larger systems.

  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. 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.

  13. Comparison of Computed Tomography Scout Based Reference Point Localization to Conventional Film and Axial Computed Tomography

    SciTech Connect

    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

  14. 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

  15. 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.

  16. Comparison with reconstruction algorithms in magnetic induction tomography.

    PubMed

    Han, Min; Cheng, Xiaolin; Xue, Yuyan

    2016-05-01

    Magnetic induction tomography (MIT) is a kind of imaging technology, which uses the principle of electromagnetic detection to measure the conductivity distribution. In this research, we make an effort to improve the quality of image reconstruction mainly via the image reconstruction of MIT analysis, including solving the forward problem and image reconstruction. With respect to the forward problem, the variational finite element method is adopted. We transform the solution of a nonlinear partial differential equation into linear equations by using field subdividing and the appropriate interpolation function so that the voltage data of the sensing coils can be calculated. With respect to the image reconstruction, a method of modifying the iterative Newton-Raphson (NR) algorithm is presented in order to improve the quality of the image. In the iterative NR, weighting matrix and L1-norm regularization are introduced to overcome the drawbacks of large estimation errors and poor stability of the reconstruction image. On the other hand, within the incomplete-data framework of the expectation maximization (EM) algorithm, the image reconstruction can be converted to the problem of EM through the likelihood function for improving the under-determined problem. In the EM, the missing-data is introduced and the measurement data and the sensitivity matrix are compensated to overcome the drawback that the number of the measurement voltage is far less than the number of the unknown. In addition to the two aspects above, image segmentation is also used to make the lesion more flexible and adaptive to the patients' real conditions, which provides a theoretical reference for the development of the application of the MIT technique in clinical applications. The results show that solving the forward problem with the variational finite element method can provide the measurement voltage data for image reconstruction, the improved iterative NR method and EM algorithm can enhance the image

  17. Comparison with reconstruction algorithms in magnetic induction tomography.

    PubMed

    Han, Min; Cheng, Xiaolin; Xue, Yuyan

    2016-05-01

    Magnetic induction tomography (MIT) is a kind of imaging technology, which uses the principle of electromagnetic detection to measure the conductivity distribution. In this research, we make an effort to improve the quality of image reconstruction mainly via the image reconstruction of MIT analysis, including solving the forward problem and image reconstruction. With respect to the forward problem, the variational finite element method is adopted. We transform the solution of a nonlinear partial differential equation into linear equations by using field subdividing and the appropriate interpolation function so that the voltage data of the sensing coils can be calculated. With respect to the image reconstruction, a method of modifying the iterative Newton-Raphson (NR) algorithm is presented in order to improve the quality of the image. In the iterative NR, weighting matrix and L1-norm regularization are introduced to overcome the drawbacks of large estimation errors and poor stability of the reconstruction image. On the other hand, within the incomplete-data framework of the expectation maximization (EM) algorithm, the image reconstruction can be converted to the problem of EM through the likelihood function for improving the under-determined problem. In the EM, the missing-data is introduced and the measurement data and the sensitivity matrix are compensated to overcome the drawback that the number of the measurement voltage is far less than the number of the unknown. In addition to the two aspects above, image segmentation is also used to make the lesion more flexible and adaptive to the patients' real conditions, which provides a theoretical reference for the development of the application of the MIT technique in clinical applications. The results show that solving the forward problem with the variational finite element method can provide the measurement voltage data for image reconstruction, the improved iterative NR method and EM algorithm can enhance the image

  18. Microcomputer Acquisition Standards and Controls.

    ERIC Educational Resources Information Center

    Wold, Geoffrey H.

    1987-01-01

    Increased use of microcomputers in schools can be implemented more effectively when management develops acquisitions standards and controls. Technical standards as well as operational and documentation standards are outlined. (MLF)

  19. 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)

  20. 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)

  1. Microcomputer Activities and Occupational Therapy.

    ERIC Educational Resources Information Center

    Wall, Nancy

    1984-01-01

    Directed to occupational therapists, the article focuses on the applications of microcomputers to services for developmentally disabled persons. Noted are computer devices (input, output, software, and firmware); computer programs (basic and sophisticated instruction, graphics); and LOGO, a computer language.

  2. Comparison of Swedish and Norwegian Use of Cone-Beam Computed Tomography: a Questionnaire Study

    PubMed Central

    Strindberg, Jerker Edén; Hol, Caroline; Torgersen, Gerald; Møystad, Anne; Nilsson, Mats; Hellén-Halme, Kristina

    2015-01-01

    ABSTRACT Objectives Cone-beam computed tomography in dentistry can be used in some countries by other dentists than specialists in radiology. The frequency of buying cone-beam computed tomography to examine patients is rapidly growing, thus knowledge of how to use it is very important. The aim was to compare the outcome of an investigation on the use of cone-beam computed tomography in Sweden with a previous Norwegian study, regarding specifically technical aspects. Material and Methods The questionnaire contained 45 questions, including 35 comparable questions to Norwegian clinics one year previous. Results were based on inter-comparison of the outcome from each of the two questionnaire studies. Results Responses rate was 71% in Sweden. There, most of cone-beam computed tomography (CBCT) examinations performed by dental nurses, while in Norway by specialists. More than two-thirds of the CBCT units had a scout image function, regularly used in both Sweden (79%) and Norway (75%). In Sweden 4% and in Norway 41% of the respondents did not wait for the report from the radiographic specialist before initiating treatment. Conclusions The bilateral comparison showed an overall similarity between the two countries. The survey gave explicit and important knowledge of the need for education and training of the whole team, since radiation dose to the patient could vary a lot for the same kind of radiographic examination. It is essential to establish quality assurance protocols with defined responsibilities in the team in order to maintain high diagnostic accuracy for all examinations when using cone-beam computed tomography for patient examinations. PMID:26904179

  3. 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

  4. 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.

  5. Decisions, Decisions, Decisions: Help in Choosing Microcomputer Software and Hardware.

    ERIC Educational Resources Information Center

    Pugh, W. Jean; Fredenburg, Anne M.

    1985-01-01

    This bibliography, prepared with the information specialist, end-user, and administrator in mind, presents citations to 167 journal articles that provide concrete comparisons of commercially-available microcomputer software packages and hardware equipment. An index divided into software and hardware sections with references to type of comparison…

  6. Microcomputer log analysis system

    SciTech Connect

    Ostrander, C.

    1984-04-01

    A comprehensive friendly log analysis system for use on a microcomputer requires only average log analysis skills. Most systems require both log analysis and computer professional for operation. This one has many capabilities: (1) data entry is handled by office personnel after minimal training; (2) entered data is filed and cataloged for future retrieval and analysis; (3) the system can handle more than 9,000,000 ft (2700 km) of log data in over 60,000 files; (4) all data can be edited; (5) searches and listings can be made using factors such as formation names; (6) facsimile reproductions can be made of any log on file; (7) a screening program turns the system into a sophisticated hand calculator to quickly determine zones of interest; and (8) up to 1100 ft (335 m) of contiguous data from a well can be analyzed in one run. Innovative features include: (1) a discriminating factor to separate reservoirs for individual attention concerning rock type, fluid content and potential reserves; and (2) a written report of each reservoir using artificial intelligence. The report discusses, among other things, the rock type and its consistency, comparing the system finding with the geologist's opinion. Differences between the two will elicit alternative analyses.

  7. Global seismic tomography with sparsity constraints: Comparison with smoothing and damping regularization

    NASA Astrophysics Data System (ADS)

    Charléty, Jean; Voronin, Sergey; Nolet, Guust; Loris, Ignace; Simons, Frederik J.; Sigloch, Karin; Daubechies, Ingrid C.

    2013-09-01

    We present a realistic application of an inversion scheme for global seismic tomography that uses as prior information the sparsity of a solution, defined as having few nonzero coefficients under the action of a linear transformation. In this paper, the sparsifying transform is a wavelet transform. We use an accelerated iterative soft-thresholding algorithm for a regularization strategy, which produces sparse models in the wavelet domain. The approach and scheme we present may be of use for preserving sharp edges in a tomographic reconstruction and minimizing the number of features in the solution warranted by the data. The method is tested on a data set of time delays for finite-frequency tomography using the USArray network, the first application in global seismic tomography to real data. The approach presented should also be suitable for other imaging problems. From a comparison with a more traditional inversion using damping and smoothing constraints, we show that (1) we generally retrieve similar features, (2) fewer nonzero coefficients under a properly chosen representation (such as wavelets) are needed to explain the data at the same level of root-mean-square misfit, (3) the model is sparse or compressible in the wavelet domain, and (4) we do not need to construct a heterogeneous mesh to capture the available resolution.

  8. 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…

  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. 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. 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;…

  12. 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…

  13. Microcomputer Unit: Graphing Straight Lines.

    ERIC Educational Resources Information Center

    Hastings, Ellen H.; Yates, Daniel S.

    1983-01-01

    The material is designed to help pupils investigate how the value for slope in the equation of a line affects the inclination for the graph of an equation. A program written in BASIC designed to run on an Apple microcomputer is included. Worksheet masters for duplication are provided. (MP)

  14. Students Discuss Microcomputers and History.

    ERIC Educational Resources Information Center

    Slatta, Richard

    1987-01-01

    Reviews the authors experience in teaching a senior-level undergraduate course entitled: "Using a Microcomputer to Enhance Historical Research and Writing." The class used Ashton-Tate's FRAMEWORK, an integrated program that combines filing, outlining, word processing, and other functions. Includes the syllabus and student reactions to the course.…

  15. 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…

  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. 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…

  19. 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…

  20. Microcomputers in the Public Schools.

    ERIC Educational Resources Information Center

    Hayes, Jeanne

    1984-01-01

    A table shows the number of public schools using microcomputers, by brand, in 1982-83 and 1983-84 respectively. It reveals that Apple has extended its market dominance from 51.1 to 66.2 percent during this time. (TE)

  1. 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…

  2. Micro-computed tomography and scanning electron microscopy comparisons of two nickel-titanium rotary root canal instruments used with reciprocating motion.

    PubMed

    Kim, Hee-Chul; Hwang, You-Jeong; Jung, Da-Woon; You, Sung-Yeop; Kim, Hyeon-Cheol; Lee, WooCheol

    2013-01-01

    The single-file root canal instrumentation technique using reciprocating motion has been gaining concern. Therefore, the purpose of this study was to compare the shaping ability of single ProTaper F2 file and WaveOne Primary file when they were used in the curved root canal with reciprocation motion and to investigate the durability of the file after use with a scanning electron microscopy (SEM). Changes in structure model index (SMI), root canal volume, curvature, surface area, and degree of transportation were measured from the cross-sectional images of the prepared canals using the micro-CT system with an isotropic resolution of 16 μm. Results showed that there were no differences in the changes of root canal volume, surface area, and SMI between the two file groups after the preparation (p > 0.05). The ProTaper group showed a curvature straightening value of 25.45 ± 12.51%, while the WaveOne group showed 27.30 ± 10.91%, and there was no statistically significant difference (p > 0.05). The transportation values between the two groups showed no significant differences (p > 0.05). SEM revealed that 60% of ProTaper files showed initiation of microcracks on the surface while those were detected on the only one WaveOne file. The single-file technique using either WaveOne Primary or ProTaper F2 can be safely used under each reciprocating motion without creating an increased apical transportation in curved canals. However, the metallurgic property resists cyclic fatigue was more favorable with WaveOne under the scanning evaluation.

  3. Comparison of global ionospheric maps, high-orbital and low-orbital radio tomography.

    NASA Astrophysics Data System (ADS)

    Kunitsyn, Viacheslav E.; Andreeva, Elena S.; Nesterov, Ivan A.; Kalashnikova, Svetlana A.; Padokhin, Artem M.

    2010-05-01

    Observations on the GPS receivers networks which are being actively developed at present provide the input data for constructing global ionospheric maps (GIM) of the distributions of total electron content (TEC) in the ionosphere. The methods applied in the GIM construction at several data processing centers are different although all based on the common idea of finding the appropriate model parameters to fit the selected model of the vertical distribution of electron density to the observed GPS data. At the same time, the existing global IGS network together with several regional GPS networks open the possibility for solving the problem of 4D (spatiotemporal) ionospheric radio tomography (RT) based on the data of high-orbiting navigational satellite systems (the high orbital radio tomography, HORT). The approaches used in HORT are similar to those applied and found highly efficient in 2D low-orbital radio tomography (LORT). The purpose of the present work is to compare TEC estimations based on GIMs, calculated by different centers, with HORT and LORT reconstructions observed at different geomagnetic activity. The results of such comparison along RT systems in Russia and Alaska during the periods of geomagnetic storms of 2003-2004 are reported and discussed. The reconstructions for quiet periods are basically similar, although higher GIM and HORT TEC compared to LORT TEC, which might be due to the plasmaspheric contribution, are still noteworthy. However, during the geomagnetic storms, GIM TEC significantly differs from either LORT and HORT TEC. The work was supported by the Russian Foundation for Basic Research (grants nos. 10-05-01126, 08-05-00676). The authors acknowledge IGS for GNSS data. We are also grateful to our colleagues in PGI and NWRS for the shared raw RT data.

  4. Contrast-enhanced [18 F] fluorodeoxyglucose-positron emission tomography/computed tomography in clinical oncology: tumor-, site-, and question-based comparison with standard positron emission tomography/computed tomography

    PubMed Central

    2014-01-01

    Background The present study aimed to evaluate the added value of contrast-enhanced computed tomography (ceCT) in comparison to standard, non-enhanced CT in the context of a combined positron emission tomography (PET)/CT examination by means of a tumor-, site-, and clinical question-based approach. Methods Analysis was performed in 202 patients undergoing PET/CT consisting of a multiphase CT protocol followed by a whole-body PET. The Cochran Q test was performed, followed by a multiple comparisons correction (McNemar test and Bonferroni adjustment), to compare standard and contrast-enhanced PET (cePET/CT). Histopathology or clinical-radiologic follow-up greater than 1 year was used as a reference. Results cePET/CT showed significantly different results with respect to standard PET/CT in head and neck and gastrointestinal cancer (P = 0.02 and 0.0002, respectively), in the evaluation of lesions located in the abdomen (P = 0.009), and in the context of disease restaging (P = 0.003). In all these clinical scenarios, adding ceCT resulted in a distinct benefit, by yielding a higher percentage of change in patient management. Conclusion These data strongly underline the importance of strictly selecting patients for the combined exam. In particular, patient selection should not be driven solely by mere tumor classification, but should also account for the clinical question and the anatomical location of the neoplastic disease, which can significantly impact patient management. PMID:25609564

  5. Current and Future Microcomputer Capabilities: Selecting the Hardware.

    ERIC Educational Resources Information Center

    Mason, Robert M.

    1984-01-01

    Suggests guidelines for selecting microcomputers, reviews present status of microcomputer industry, projects microcomputer capabilities for 1988 and 1998, and discusses implications of recent trends on microcomputer purchasing. It is concluded that buyers interested in a microcomputer for information management will make a safe decision selecting…

  6. 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.

  7. 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.

  8. Microcomputers aid pipeline hydraulic analysis

    SciTech Connect

    Hein, M.A.; Brosius, M.

    1984-02-13

    Microcomputer technology has come a long way in the last few years, and now inexpensive desktop computers can be used to analyze fluid and heat flow in even the largest pipeline and networked piping systems. Except for network problems requiring dynamic compositional modeling and extremely large amounts of data storage, all processing, including input, calculation, and output, can be handled with the microcomputer. And, even for these large problems, a small personal computer can be used to efficiently build the input files, process the output, and generally enhance the whole computational procedure. Only a few years ago the engineer had to code up his data, give it to the keypunching department, wait several hours or days until he got his cards back, attach the appropriate job control language (JCL), submit the deck to the computer department, wait several more hours or days to receive the final results, and finally pore over endless tables of numbers to interpret the results. Further, if there was an error in the input or if several case studies were required, he had to go through the whole process repeatedly. With the advent of the microcomputer with graphics packages, light pens, graphic pads, tens of megaword, fast-access, disk storage, and versatile, user-friendly software the data preparation, interpretation, and computational times for hydraulic piping simulation are cut by an order of magnitude.

  9. 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.

  10. Coral surface area quantification-evaluation of established techniques by comparison with computer tomography

    NASA Astrophysics Data System (ADS)

    Naumann, M. S.; Niggl, W.; Laforsch, C.; Glaser, C.; Wild, C.

    2009-03-01

    The surface area of scleractinian corals represents an important reference parameter required for various aspects of coral reef science. However, with advancements in detection accuracy and novel approaches for coral surface area quantification, evaluation of established techniques in comparison with state-of-the-art technology gains importance to coral researchers. This study presents an evaluation of methodological accuracy for established techniques in comparison to a novel approach composed of computer tomography (CT) and 3-dimensional surface reconstruction. The skeleton surface area of reef corals from six genera representing the most common morphological growth forms was acquired by CT and subsequently measured by computer-aided 3-dimensional surface reconstruction. Surface area estimates for the same corals were also obtained by application of four established techniques: Simple and Advanced Geometry, Wax Coating and Planar Projection Photography. Comparison of the resulting area values revealed significant differences between the majority (82%) of established techniques and the CT reference. Genus-specific analysis assigned the highest accuracy to geometric approximations (Simple or Advanced Geometry) for the majority of assessed coral genera (maximum accuracy: 104%; Simple Geometry with Montipora sp.). The commonly used and invasive Wax Coating technique reached intermediate accuracy (47-74%) for the majority of genera, but performed outstanding in the measurement of branching Acropora spp. corals (maximum accuracy: 101%), while the Planar Projection Photography delivered genera-wide low accuracy (12-36%). Comparison of area values derived from established techniques and CT additionally yielded approximation factors (AFs) applicable as factors in the mathematical improvement of surface area estimates by established techniques in relation to CT reference accuracy.

  11. Comparison of computed tomography dose index in polymethyl methacrylate and nylon dosimetry phantoms.

    PubMed

    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

  12. Variations in optical coherence tomography resolution and uniformity: a multi-system performance comparison.

    PubMed

    Fouad, Anthony; Pfefer, T Joshua; Chen, Chao-Wei; Gong, Wei; Agrawal, Anant; Tomlins, Peter H; Woolliams, Peter D; Drezek, Rebekah A; Chen, Yu

    2014-07-01

    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

  13. Special computer-aided computed tomography (CT) volume measurement and comparison method for pulmonary tuberculosis (TB)

    PubMed Central

    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, R2=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. PMID:26628995

  14. 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.

  15. Accessing ERIC with Your Microcomputer. ERIC Digest.

    ERIC Educational Resources Information Center

    Klausmeier, Jane A.

    This fact sheet offers basic instructions on connecting to the ERIC database for individuals who own or have access to a microcomputer and are familiar with ERIC and how to search it through a database terminal. Software, hardware, and telephone line components necesary to make a microcomputer act as a database terminal are outlined. The…

  16. Microcomputer Software Programs for Vocational Education.

    ERIC Educational Resources Information Center

    Rodenstein, Judith, Ed.; Lambert, Roger, Ed.

    Over 200 microcomputer software packages applicable to vocational education are listed. Most of the programs are available for the Apple, TRS-80, and Commodore microcomputers. The packages have been reviewed, but have not been formally evaluated. Titles of the programs with names and addresses of the distributors are provided. Telephone numbers…

  17. 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…

  18. Using Microcomputers to Increase Productivity in Academia.

    ERIC Educational Resources Information Center

    McKenzie, Garry D.

    1984-01-01

    The expanded use of microcomputers, including word processing, to improve productivity of geological educators and students is discussed. Topic areas examined include: computer development and academic use; word processing with microcomputers; instructional uses and other applications; impacts on academia; and acquisition. (BC)

  19. 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. PMID:10278151

  20. Advanced Microcomputer Service Technician. Teacher Edition.

    ERIC Educational Resources Information Center

    Brown, A. O., III; Fulkerson, Dan, Ed.

    This manual is the second of a three-text microcomputer service and repair series. This text addresses the training needs of "chip level" technicians who work with digital troubleshooting instruments to solve the complex microcomputer problems that are sent to them from computer stores that do not have full-service facilities. The manual contains…

  1. School Districts Using Microcomputers: A National Survey.

    ERIC Educational Resources Information Center

    Hayes, Jeanne

    1983-01-01

    Discusses results of a comprehensive nationwide survey conducted in the summers of 1982 and 1983 on the number and brands of microcomputers in schools. Findings show a 118 percent increase in the number of schools using microcomputers, with Apple the most popular brand. (TE)

  2. Microcomputers as Social Facilitators in Integrated Preschools.

    ERIC Educational Resources Information Center

    Spiegel-McGill, Phyllis; And Others

    1989-01-01

    The study compared the effects of different play conditions (microcomputer, remote-control robot, or no toys) on the amount of time four dyads of handicapped/nonhandicapped children would interact during structured play. Results suggested that microcomputers may serve as social facilitators for children with significant social and language…

  3. 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…

  4. Properly Matching Microcomputer Hardware, Software Minimizes "Glitches."

    ERIC Educational Resources Information Center

    Fredenburg, Philip B.

    1986-01-01

    Microcomputer systems for school districts are best obtained by selecting the software, and matching it with hardware. Discusses criteria for software and hardware, monitors, input/output devices, backup devices, and printers. Components of two basic microcomputer systems for the business office are proposed. (MLF)

  5. Distributed Processors and Processing with Microcomputers.

    ERIC Educational Resources Information Center

    Noerr, K. T. Bivins; Noerr, P. L.

    1983-01-01

    This discussion of the role and effects of microcomputers in the information industry considers technological advances of recent times and how they may affect the future. Complexity of systems and systems control, problems of communication (machine-to-machine, machine-to-human), spread of microcomputers, and information networks and systems are…

  6. Using Calculators and Microcomputers with Exceptional Children.

    ERIC Educational Resources Information Center

    Etlinger, Leonard E.; Ogletree, Earl J.

    The focus of this document is on descriptions of calculators, microcomputers, and related educational technology and materials. Calculators are viewed as innovative teaching tools that can have both practical and pedagogical functions in the classroom to enhance understanding and achievement in mathematics. Microcomputers are seen as glorified…

  7. Automating Relational Database Design for Microcomputer Users.

    ERIC Educational Resources Information Center

    Pu, Hao-Che

    1991-01-01

    Discusses issues involved in automating the relational database design process for microcomputer users and presents a prototype of a microcomputer-based system (RA, Relation Assistant) that is based on expert systems technology and helps avoid database maintenance problems. Relational database design is explained and the importance of easy input…

  8. 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. PMID:26158079

  9. 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

  10. Ionospheric tomography over South Africa: Comparison of MIDAS and ionosondes measurements

    NASA Astrophysics Data System (ADS)

    Giday, Nigussie M.; Katamzi, Zama T.; McKinnell, Lee-Anne

    2016-01-01

    This paper aims to show the results of an ionospheric tomography algorithm called Multi-Instrument Data Analysis System (MIDAS) over the South African region. Recorded data from a network of 49-53 Global Positioning System (GPS) receivers over the South African region was used as input for the inversion. The inversion was made for April, July, October and December representing the four distinct seasons (Autumn, Winter, Spring and Summer respectively) of the year 2012. MIDAS reconstructions were validated by comparing maximum electron density of the F2 layer (NmF2) and peak height (hmF2) values predicted by MIDAS to those derived from three South African ionosonde measurements. The diurnal and seasonal trends of the MIDAS NmF2 values were in good agreement with the respective NmF2 values derived from the ionosondes. In addition, good agreement was found between the two measurements with minimum and maximum coefficients of determination (r2) between 0.84 and 0.96 in all the stations and validation days. The seasonal trend of the NmF2 values over the South Africa region has been reproduced using this inversion which was in good agreement with the ionosonde measurements. Moreover, a comparison of the International Reference Ionosphere (IRI-2012) model NmF2 values with the respective ionosonde derived NmF2 values showed to have higher deviation than a similar comparison between the MIDAS reconstruction and the ionosonde measurements. However, the monthly averaged hmF2 values derived from IRI 2012 model showed better agreement than the respective MIDAS reconstructed hmF2 values compared with the ionosonde derived hmF2 values.The performance of the MIDAS reconstruction was observed to deteriorate with increased geomagnetic conditions. MIDAS reconstructed electron density were slightly elevated during three storm periods studied (24 April, 15 July and 8 October) which was in good agreement with the ionosonde measurements.

  11. Comparison of thermal corneal lesions by optical coherence tomography (OCT) and polarization histology

    NASA Astrophysics Data System (ADS)

    Koop, Norbert; Brinkmann, Ralf; Kaftan, Bjorn; Asiyo-Vogel, Mary; Engelhardt, Ralf; Birngruber, Reginald

    1996-12-01

    Corneal thermal lesions as typically applied in laser thermokeratoplasty were investigated with optical coherence tomography (OCT) and polarization microscopy. Both methods were used to compare the lesions with respect to the extent and degree of thermal denaturation. The coagulations wee applied on enucleated porcine eyes using a continuously emitting laser diode at a wavelength of 1.86 micrometers . The self developed OCT-system has an axial and lateral resolution of 15-20 micrometers and 26-48 micrometers , respectively, and was used to perform cross sections through the lesions. After OCT on the intact globe, the sections were fixed in formalin and embedded in paraffin. The sections were stained with sirius red and analyzed by polarization light microscopy. The comparison of the backscattered light of the OCT image with the changes in birefringence detected with the polarization microscopy technique found to be in good agreement. Up to four changes in birefringence detected with the polarization microscopy technique found to be in good agreement.Up to four different degrees of denaturation zones could be classified in both methods. OCT findings taken from a noninvasive method and correlated with histological experiences can be used to control the extent and degree of corneal lesions and monitor their healing response.

  12. 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…

  13. Microcomputer logarithmic time base generator

    NASA Astrophysics Data System (ADS)

    Wills, L. J.; Ly, Nhan G.

    1985-11-01

    A new circuit is introduced to generate the logarithmic time base function with good resolution. By using a single-chip microcomputer with EPROM program storage, the circuitry is simplified and can be easily reproduced. The output function covers more than six decades of time and has 590 discrete points per decade with an accuracy of one discrete point per decade or ±0.16%. The design overcomes two well-known problems in using the logarithmic time base. First because the time increments are derived from a real-time register there is a precise reference for zero time, and second a series of time base interval marks are output for correctly calibrating the time axis.

  14. Microcomputer control of power converters

    SciTech Connect

    Alegria, C.M.; Freris, L.L.; Paiva, J.P.

    1984-08-01

    Thyristor power converters are charac terized by an inherent discrete control action and are, therefore, particularly well suited to on - line control by microcomputers. The paper presents a new design of digital controllers based upon powerful 16-bit or bit -slice microprocessors, which provide high firing time resolution and enough computing power to implement sophis ticated control strategies. Both hardware and software are discussed, with special emphasis on the firing con trol algorithms. The properties of Pulse Frequency Con trol (PFC) and Pulse Phase Control (PPC) are examined and small-signal discrete models are presented. These models are used in the analysis of constant current and constant extinction angle control through the z-transform method.

  15. Networking of microcomputers in the radiology department.

    PubMed

    Markivee, C R

    1985-10-01

    A microcomputer may be installed in any of several areas in a radiology department or office to automate data processing. Such areas include the reception desk, the transcription office, the quality-control station, and remote or satellite radiography rooms. Independent microcomputers can be interconnected by networking, using small hardware and software packages and cables, to effect communication between them, afford access to a common data base, and share peripheral devices such as hard disks and printers. A network of microcomputers can perform many of the functions of a larger minicomputer system at lower cost and can be assembled in small modules as budgetary constraints allow. PMID:3876011

  16. 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

  17. 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.

  18. Microcomputers: "A New Era at Ramapo Catskill."

    ERIC Educational Resources Information Center

    Freund, Alfred L.

    1983-01-01

    Discussion of the use of microcomputers in a cooperative public library system notes library management applications in areas of clerical work, word processing, book ordering, inventories, special collection catalogs, mailing lists, and a union list of serials. (EJS)

  19. Utilization of Educationally Oriented Microcomputer Based Laboratories

    ERIC Educational Resources Information Center

    Fitzpatrick, Michael J.; Howard, James A.

    1977-01-01

    Describes one approach to supplying engineering and computer science educators with an economical portable digital systems laboratory centered around microprocessors. Expansion of the microcomputer based laboratory concept to include Learning Resource Aided Instruction (LRAI) systems is explored. (Author)

  20. Introducing a Microcomputer into Adult Education Classes.

    ERIC Educational Resources Information Center

    Bostock, Stephen; Seifert, Roger

    1983-01-01

    There are now plenty of adult education classes on how to use a computer; this article is an account of how microcomputers were actually used as an aid to learning in the biological, natural, and social sciences. (Author/SSH)

  1. The Practical Use of Microcomputers in Rehabilitation.

    ERIC Educational Resources Information Center

    Vanderheiden, Gregg C.

    1983-01-01

    The application of microcomputers for handicapped individuals has tremendous potential. Barriers needing research include: access by the handicapped to the available software, aids that are portable, the problem of obsolescence. (SEW)

  2. 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)

  3. Microcomputer-Based Pediatric Health Maintenance System

    PubMed Central

    Maxwell, Carron M.; Philipsborn, Herbert F.; Napier, Robin; Nigro, Rise

    1983-01-01

    The Pediatric Evaluation, Research and Tracking System (PERTS) is an automated health maintenance and tracking system implemented on a microcomputer. This summary of significant medical information is used to support more effective patient care, operations research, training and program planning for a pediatric group practice in a suburban teaching hospital. The System's programs are designed to be convenient for use by health professionals and clerical staff. The system is implemented on a 64K microcomputer using MBASIC under MP/M and KSAM.

  4. Development of CCD-based optical computed tomography and comparison with single-beam optical CT scanner

    NASA Astrophysics Data System (ADS)

    Chang, Y. J.

    2015-01-01

    This study reports on the development of CCD-based optical computed tomography (CT) CT-s2. A commercially available 10× fast optical computed tomography scanner (OCTOPUSTM-10X, MGS Research, Inc., Madison, CT, USA) was used for comparison. NIPAM polymer gel dosimeter was used to validate the performance of CT-s2. The gamma pass rate can reach 96.00% when using a 3% dose difference and 3 mm dose-to-agreement criteria. The results of CT-s2 are as good as those of the single-beam optical-CT scanner, but the scanning time of CT-s2 is only one-tenth of that of the single-beam optical-CT scanner.

  5. Comparison of magnetic resonance imaging and computed tomography in the preoperative staging of rectal cancer.

    PubMed

    Guinet, C; Buy, J N; Ghossain, M A; Sézeur, A; Mallet, A; Bigot, J M; Vadrot, D; Ecoiffier, J

    1990-03-01

    Nineteen patients with middle and lower rectal carcinomas were operated on, with abdominoperineal resection in 10 patients, lower anterior resection with coloanal anastomosis in 6 patients, and colorectal anastomosis in 3 patients. The distance of the lower margin of the tumor to insertion of the levator ani on the rectal wall was correctly evaluated by computed tomography in 12 (63%) of 19 patients and by magnetic resonance imaging in 13 (68%) of 19 patients, while digital examination correctly assessed the distance in 15 (79%) of 19 patients. Computed tomography and magnetic resonance imaging were unable to assess extension through the rectal wall. No significant difference was observed between computed tomography and magnetic resonance imaging in assessing extension to the perivesical fat, adjacent organs, pelvic side wall, or lymph nodes. According to the TNM classification, magnetic resonance imaging correctly staged 74% (14/19) of carcinomas, while computed tomography correctly staged 68% (13/19).

  6. Blow-out fractures of the orbit: a comparison of computed tomography and conventional radiography with anatomic correlation

    SciTech Connect

    Hammeschlag, S.B.; Hughes, S.; O'Reilly, G.V.; Naheedy, M.H.; Rumbaugh, C.L.

    1982-05-01

    Orbital blow-out fractures were experimentally created in eight human cadavers. Each orbit underwent conventional radiographic studies, complex motion tomography, and computed tomographic examinations. A comparison of the three modalities was made. Anatomical correlation was obtained by dissecting the orbits. The significance of medial-wall fractures and enophthalmos is discussed. Limitation of inferior rectus muscle mobility is thought to be a result of muscle kinking associated with orbital fat-pad prolapse at the fracture site, rather than muscle incarceration. Blow-out fractures should be evaluated by computed tomographic computer reformations in the oblique sagittal plane.

  7. Comparison of hydraulic tomography with traditional methods at a highly heterogeneous site.

    PubMed

    Berg, Steven J; Illman, Walter A

    2015-01-01

    Over the past several decades, different groundwater modeling approaches of various complexities and data use have been developed. A recently developed approach for mapping hydraulic conductivity (K) and specific storage (Ss ) heterogeneity is hydraulic tomography, the performance of which has not been compared to other more "traditional" methods that have been utilized over the past several decades. In this study, we compare seven methods of modeling heterogeneity which are (1) kriging, (2) effective parameter models, (3) transition probability/Markov Chain geostatistics models, (4) geological models, (5) stochastic inverse models conditioned to local K data, (6) hydraulic tomography, and (7) hydraulic tomography conditioned to local K data using data collected in five boreholes at a field site on the University of Waterloo (UW) campus, in Waterloo, Ontario, Canada. The performance of each heterogeneity model is first assessed during model calibration. In particular, the correspondence between simulated and observed drawdowns is assessed using the mean absolute error norm, (L1 ), mean square error norm (L2 ), and correlation coefficient (R) as well as through scatterplots. We also assess the various models on their ability to predict drawdown data not used in the calibration effort from nine pumping tests. Results reveal that hydraulic tomography is best able to reproduce these tests in terms of the smallest discrepancy and highest correlation between simulated and observed drawdowns. However, conditioning of hydraulic tomography results with permeameter K data caused a slight deterioration in accuracy of drawdown predictions which suggests that data integration may need to be conducted carefully.

  8. Comparison of different dose reduction system in computed tomography for orthodontic applications

    PubMed Central

    FANUCCI, E.; FIASCHETTI, V.; OTTRIA, L.; MATALONI, M; ACAMPORA, V.; LIONE, R.; BARLATTANI, A.; SIMONETTI, G.

    2011-01-01

    SUMMARY To correlate different CT system: MSCT (multislice computed tomography) with different acquisition parameters (100KV, 80KV), different reconstruction algorithm (ASIR) and CBCT (cone beam computed tomography) examination in terms of absorbed X-ray dose and diagnostic accuracy. 80 KV protocols compared with 100 KV protocols resulted in reduced total radiation dose without relevant loss of diagnostic image information and quality. CBCT protocols compared with 80 KV MSCT protocols resulted in reduced total radiation dose but loss of diagnostic image information and quality although no so relevant. In addition the new system applies to equipment ASIR applicable on MSCT allows 50% of the dose without compromising image quality. PMID:23285397

  9. Mediastinal lymph node staging of non-small-cell lung cancer: a prospective comparison of computed tomography and positron emission tomography.

    PubMed

    Scott, W J; Gobar, L S; Terry, J D; Dewan, N A; Sunderland, J J

    1996-03-01

    We compared the abilities of positron emission tomography and computed tomography to detect N2 or N3 lymph node metastases (N2 or N3) in patients with lung cancer. Positron emission tomography detects increased rates of glucose uptake, characteristic of malignant cells. Patients with peripheral tumors smaller than 2 cm and a normal mediastinum were ineligible. All patients underwent computed tomography, positron emission tomography, and surgical staging. The American Thoracic Society lymph node map was used. Computed and positron emission tomographic scans were read by separate radiologists blinded to surgical staging results. Lymph nodes were "positive" by computed tomography if larger than 1.0 cm in short-axis diameter. Standardized uptake values were recorded from areas on positron emission tomography corresponding to those from which biopsy specimens were taken; if greater than 4.2, they were called "positive." Seventy-five lymph node stations (2.8 per patient) were analyzed in 27 patients. Computed tomography incorrectly staged the mediastinum as positive for metastases in three patients and as negative for metastases in three patients. Sensitivity and specificity of computed tomographic scans were 67% and 83%, respectively. Positron emission tomography correctly staged the mediastinum in all 27 patients. When analyzed by individual node station, there were four false positive and four false negative results by computed tomography (sensitivity = 60%, specificity = 93%, positive predictive value = 60%). Positron emission tomography mislabeled one node station as positive (100% sensitive, 98% specific, positive predictive value 91%). The differences were significant when the data were analyzed both for individual lymph node stations (p = 0.039) and for patients (p = 0.031) (McNemar test). Positron emission tomography and computed tomography are more accurate than computed tomography alone in detecting mediastinal lymph node metastases from non-small-cell lung

  10. Factor analysis and predictive validity of microcomputer-based tests

    NASA Technical Reports Server (NTRS)

    Kennedy, R. S.; Baltzley, D. R.; Turnage, J. J.; Jones, M. B.

    1989-01-01

    11 tests were selected from two microcomputer-based performance test batteries because previously these tests exhibited rapid stability (less than 10 min, of practice) and high retest reliability efficiencies (r greater than 0.707 for each 3 min. of testing). The battery was administered three times to each of 108 college students (48 men and 60 women) and a factor analysis was performed. Two of the three identified factors appear to be related to information processing ("encoding" and "throughput/decoding"), and the third named an "output/speed" factor. The spatial, memory, and verbal tests loaded on the "encoding" factor and included Grammatical Reasoning, Pattern Comparison, Continuous Recall, and Matrix Rotation. The "throughput/decoding" tests included perceptual/numerical tests like Math Processing, Code Substitution, and Pattern Comparison. The output speed factor was identified by Tapping and Reaction Time tests. The Wonderlic Personnel Test was group administered before the first and after the last administration of the performance tests. The multiple Rs in the total sample between combined Wonderlic as a criterion and less than 5 min. of microcomputer testing on Grammatical Reasoning and Math Processing as predictors ranged between 0.41 and 0.52 on the three test administrations. Based on these results, the authors recommend a core battery which, if time permits, would consist of two tests from each factor. Such a battery is now known to permit stable, reliable, and efficient assessment.

  11. Comparison of Computed Tomography and Chest Radiography in the Detection of Rib Fractures in Abused Infants

    ERIC Educational Resources Information Center

    Wootton-Gorges, Sandra L.; Stein-Wexler, Rebecca; Walton, John W.; Rosas, Angela J.; Coulter, Kevin P.; Rogers, Kristen K.

    2008-01-01

    Purpose: Chest radiographs (CXR) are the standard method for evaluating rib fractures in abused infants. Computed tomography (CT) is a sensitive method to detect rib fractures. The purpose of this study was to compare CT and CXR in the evaluation of rib fractures in abused infants. Methods: This retrospective study included all 12 abused infants…

  12. [General-purpose microcomputer for medical laboratory instruments].

    PubMed

    Vil'ner, G A; Dudareva, I E; Kurochkin, V E; Opalev, A A; Polek, A M

    1984-01-01

    Presented in the paper is the microcomputer based on the KP580 microprocessor set. Debugging of the hardware and the software by using the unique debugging stand developed on the basis of microcomputer "Electronica-60" is discussed.

  13. The Power of the New Microcomputers: Challenge and Opportunity.

    ERIC Educational Resources Information Center

    Rumsey, Eric

    1990-01-01

    Describes current developments in microcomputer technology, including CD-ROM, the 80386 microprocessor, and the graphic user interface. It is argued that, as the information handling capacity of microcomputers increases, the microcomputer industry will increasingly market information to end users, and the library will be challenged to provide the…

  14. Exceptional Children and Microcomputers, A Survey of Public School Applications.

    ERIC Educational Resources Information Center

    Crowner, T. Timothy

    Telephone interviews on the use of microcomputers in special education were administered to personnel in 25 districts (drawn from a random sample of the largest school districts in the United States) on the following topics: coordination of microcomputers; numbers of microcomputers owned and used; pragmatic uses; funding; brands used; selection,…

  15. Microcomputer-Administered Research: What it Means for Educational Researchers.

    ERIC Educational Resources Information Center

    Johnson, Craig W.

    1982-01-01

    The development of the microcomputer offers advantages for behavioral science and educational research. Among the potentials of microcomputer use are enhanced capacities for precise replication and extension, measurement, and experimental control and randomization, and the relative economy that microcomputer-administered experimental treatments…

  16. A Low Cost Microcomputer Laboratory for Investigating Computer Architecture.

    ERIC Educational Resources Information Center

    Mitchell, Eugene E., Ed.

    1980-01-01

    Described is a microcomputer laboratory at the United States Military Academy at West Point, New York, which provides easy access to non-volatile memory and a single input/output file system for 16 microcomputer laboratory positions. A microcomputer network that has a centralized data base is implemented using the concepts of computer network…

  17. Fabricating a Microcomputer on a Single Silicon Wafer

    NASA Technical Reports Server (NTRS)

    Evanchuk, V. L.

    1983-01-01

    Concept for "microcomputer on a slice" reduces microcomputer costs by eliminating scribing, wiring, and packaging of individual circuit chips. Low-cost microcomputer on silicon slice contains redundant components. All components-central processing unit, input/output circuitry, read-only memory, and random-access memory (CPU, I/O, ROM, and RAM) on placed on single silicon wafer.

  18. Reconstruction in interferometric synthetic aperture microscopy: comparison with optical coherence tomography and digital holographic microscopy.

    PubMed

    Sheppard, Colin J R; Kou, Shan Shan; Depeursinge, Christian

    2012-03-01

    It is shown that the spatial frequencies recorded in interferometric synthetic aperture microscopy do not correspond to exact backscattering [as they do in unistatic synthetic aperture radar (SAR)] and that the reconstruction process based on SAR is therefore based on an approximation. The spatial frequency response is developed based on the three-dimensional coherent transfer function approach and compared with that in optical coherence tomography and digital holographic microscopy.

  19. Microcomputer Simulation of Enzyme Kinetic Behaviour.

    ERIC Educational Resources Information Center

    Gill, R. A.

    1984-01-01

    Describes a program which simulates the kinetic behavior of a "typical" enzyme. Program objectives, background to the kinetic model used in the simulation, major program features, typical results obtained, and a note on the availability of the program (written in BASIC for Commodore microcomputer) are included. (JN)

  20. A Modular System of Interfacing Microcomputers.

    ERIC Educational Resources Information Center

    Martin, Peter

    1983-01-01

    Describes a system of interfacing allowing a range of signal conditioning and control modules to be connected to microcomputers, enabling execution of such experiments as: examining rate of cooling; control by light-activated switch; pH measurements; control frequency of signal generators; and making automated measurements of frequency response of…

  1. Sheet Music Index on a Microcomputer.

    ERIC Educational Resources Information Center

    Carter, Nancy F.

    1983-01-01

    Describes procedures followed in the use of a microcomputer to develop an index to a collection of vocal sheet music at the Music Library of the University of Colorado. Indexes generated using four fields--title, composer's last name, lyricist's last name, and first line--are noted. (EJS)

  2. Microcomputers: Tools for Developing Technological Literacy.

    ERIC Educational Resources Information Center

    Liao, Thomas T.

    1983-01-01

    Describes a course in which undergraduate students learn to program microcomputers while learning about its applications and ramifications. Descriptions of software developed for the course are also provided. These include yellow light (traffic flow), domestic electrical energy use/cost, water pollution, and supermarket automation. (CN)

  3. Computense: Verb Drills on a Microcomputer.

    ERIC Educational Resources Information Center

    Dolphin, Emil

    1989-01-01

    A microcomputer program providing extensive and constantly changing practice with 35 irregular French verbs in 6 tenses is described. The program's objectives are to establish lateral associations between tense forms, provide continuous opportunity for recall, and shorten correct response time. (Author/MSE)

  4. Evaluation of Five Microcomputer CAD Packages.

    ERIC Educational Resources Information Center

    Leach, James A.

    1987-01-01

    Discusses the similarities, differences, advanced features, applications and number of users of five microcomputer computer-aided design (CAD) packages. Included are: "AutoCAD (V.2.17)"; "CADKEY (V.2.0)"; "CADVANCE (V.1.0)"; "Super MicroCAD"; and "VersaCAD Advanced (V.4.00)." Describes the evaluation of the packages and makes recommendations for…

  5. Microcomputers: An Available Technology for Special Education.

    ERIC Educational Resources Information Center

    Joiner, Lee Marvin; And Others

    1980-01-01

    The article describes the capabilities and features of basic microcomputer systems and describes special education applications: computer assisted instruction, prosthesis, testing, communication, and enhancing personal relations. Problems such as the availability of authoring languages, high quality educational software, and computer safety are…

  6. Microcomputer Peripheral Service Technician. Teacher Edition.

    ERIC Educational Resources Information Center

    Brown, A. O., III; Fulkerson, Dan, Ed.

    This manual is the third of a three-text microcomputer service and repair series. This text is designed to assist instructors in teaching service and repair procedures for floppy disk drives, printers, and monitors. The manual contains five units. Each instructional unit includes some or all of these basic components: performance objectives,…

  7. Basic Microcomputer Service Technician. Teacher Edition.

    ERIC Educational Resources Information Center

    Brown, A. O., III; Fulkerson, Dan, Ed.

    This manual is the first of three manuals for teaching repair skills to entry-level microcomputer service technicians. Although it focuses on basic computer repair skills, it also highlights the people skills needed by service providers. The manual contains 11 units. Each instructional unit includes some or all of these basic components:…

  8. Microcomputer Analysis of Children's Language Samples.

    ERIC Educational Resources Information Center

    Rosenkoetter, Sharon E.; Rice, Mabel L.

    The workshop paper examines the use of microcomputer packages to analyze spontaneous language samples of children with communication disorders. Advantages of computerized analysis are seen to include time saving, more efficient data management, and increased objectivity. To help consumers determine which programs to buy, four aspects are…

  9. Micro-Computers in Biology Inquiry.

    ERIC Educational Resources Information Center

    Barnato, Carolyn; Barrett, Kathy

    1981-01-01

    Describes the modification of computer programs (BISON and POLLUT) to accommodate species and areas indigenous to the Pacific Coast area. Suggests that these programs, suitable for PET microcomputers, may foster a long-term, ongoing, inquiry-directed approach in biology. (DS)

  10. Issues and Concerns in Special Education Microcomputing.

    ERIC Educational Resources Information Center

    Maddux, Cleborne D.

    1986-01-01

    Discussion of microcomputer use in public elementary schools focuses on the field of special education. Two main ways of using computers are described: (1) traditional uses, including administration, computer-assisted instruction, and assessment; and (2) new applications, including programming, word processing, simulations, and prosthetic aids…

  11. Computer-Assisted Microcomputer Preventive Maintenance.

    ERIC Educational Resources Information Center

    Ives, David J.

    1993-01-01

    Proposes a solution to the problem of preventive microcomputer maintenance in libraries. The strategy involves a batch program, small paper form, simple WordPerfect macro, and on-diskette log form which saves time, quickly generates standard reports, increases efficiency, eliminates most paperwork, and offers the flexibility for modification and…

  12. Microcomputer Listens to the Coefficient of Restitution.

    ERIC Educational Resources Information Center

    Smith, P. A.; And Others

    1981-01-01

    Describes a procedure for determining the coefficient of restitution using a microcomputer which collects and sends data to a large computer where analysis is done and graphical output is generated. The data collection hardware and software are described, and results are illustrated. (Author/SK)

  13. Microcomputers for Libraries: Features, Descriptions, Evaluations.

    ERIC Educational Resources Information Center

    Warden, William H.; Warden, Bette M.

    1983-01-01

    Discusses major features of microcomputers (word length, memory, size, disk size and capacity, central processing unit speed, peripherals, software) and provides descriptions of 19 models. Comparative analysis on basis of cost, software support, machine capacity, storage capacity, and types of peripherals is presented. A 173-item bibliography is…

  14. Microcomputers in Education: Why Is Earlier Better?

    ERIC Educational Resources Information Center

    Cuffaro, Harriet K.

    1984-01-01

    Microcomputers are not necessarily a desirable teaching/learning tool for young children. Learning styles of the preschool child are not often compatible with computer assisted instruction techniques. An examination of the types of available programing activities and software is presented. (DF)

  15. Managing Microcomputer Technology as an Organizational Resource.

    ERIC Educational Resources Information Center

    Khosrowpour, Mehdi; Amoroso, Donald

    With the realization that microcomputers provide an extraordinary value to the organization follows the need to address a variety of issues in order to more effectively manage these resources. Each of the 14 chapters, consisting of papers written by different authors, represents a different perspective existing in organizations with respect to the…

  16. Microcomputer Software for Teaching German: An Evaluation.

    ERIC Educational Resources Information Center

    Cornick, Lisa

    This report examines the strengths and weaknesses of the following 12 microcomputer programs: (1) Language Teacher Series: TRS-80; (2) Language Teacher Series: Atari; (3) Apfeldeutsch; (4) Author I; (5) Dasher; (6) The Definite Article; (7) Flashcard; (8) German Packages I, II, and III; (9) German Vocabulary Builder; (10) The Linguist; (11)…

  17. The Impact of Microcomputers on Composition Students.

    ERIC Educational Resources Information Center

    Hocking, Joan

    To determine whether computer assisted instruction was just a fad or a viable alternative to traditional methods for teaching English composition, a microcomputer was used in a traditional college freshman English course. The class was divided into small groups: some went to the computer lab, while others worked in the classroom. Interactive…

  18. Microcomputers for Information Storage and Retrieval.

    ERIC Educational Resources Information Center

    Kanters, Ben

    1983-01-01

    Report on use of the microcomputer for information storage and retrieval (ISR) notes hardware (floppy disks, keyboard, screen, printer); functions of ISR software; standardization of the operating system; database creation; data entry; indexing; search process; choice of ISR software package; software market and user; training and instruction; and…

  19. Developing Resource Support for Educators Using Microcomputers.

    ERIC Educational Resources Information Center

    Martinez, Carole

    This working paper documents the efforts of a professional information center (PIC) in Denver to provide resources that aid teachers and administrators in selecting software programs for varied microcomputer uses. The report outlines the development of PIC as a coordinator and clearinghouse for organizing and disseminating information on computers…

  20. Teaching Real Science with a Microcomputer.

    ERIC Educational Resources Information Center

    Naiman, Adeline

    1983-01-01

    Discusses various ways science can be taught using microcomputers, including simulations/games which allow large-scale or historic experiments to be replicated on a manageable scale in a brief time. Examples of several computer programs are also presented, including "Experiments in Human Physiology,""Health Awareness Games,""Heredity Dog," and…

  1. Criteria for the Evaluation of Microcomputer Courseware.

    ERIC Educational Resources Information Center

    Cohen, Vicki Blum

    1983-01-01

    Discusses attributes which are offered as set of standards to judge instructional software--those unique to design of microcomputer courseware and those included in design of all instruction. Curriculum role, modes of interaction, computer managed instruction, graphics, feedback, packaging, and manuals are noted. Fourteen references are included.…

  2. A Microcomputer-Controlled Measurement of Acceleration.

    ERIC Educational Resources Information Center

    Crandall, A. Jared; Stoner, Ronald

    1982-01-01

    Describes apparatus and method used to allow rapid and repeated measurement of acceleration of a ball rolling down an inclined plane. Acceleration measurements can be performed in an hour with the apparatus interfaced to a Commodore PET microcomputer. A copy of the BASIC program is available from the authors. (Author/JN)

  3. Microcomputer-Based Programs for Pharmacokinetic Simulations.

    ERIC Educational Resources Information Center

    Li, Ronald C.; And Others

    1995-01-01

    Microcomputer software that simulates drug-concentration time profiles based on user-assigned pharmacokinetic parameters such as central volume of distribution, elimination rate constant, absorption rate constant, dosing regimens, and compartmental transfer rate constants is described. The software is recommended for use in undergraduate…

  4. Scheduling Software for MS-DOS Microcomputers.

    ERIC Educational Resources Information Center

    Carlson, David H.; Prior, Barbara

    1991-01-01

    Identifies four microcomputer-based software packages for scheduling and evaluates their usefulness for scheduling employees in a library setting. Evaluation criteria are applied to (1) Schedule Master, from Schedule Master Corporation; (2) Schedule Plus, from Cyclesoft, Inc.; (3) Who Works When, from Newport Systems; and (4) Working Hours, from…

  5. The Hidden Costs of Owning a Microcomputer.

    ERIC Educational Resources Information Center

    McDole, Thomas L.

    Before purchasing computer hardware, individuals must consider the costs associated with the setup and operation of a microcomputer system. Included among the initial costs of purchasing a computer are the costs of the computer, one or more disk drives, a monitor, and a printer as well as the costs of such optional peripheral devices as a plotter…

  6. RESPSYST: An Interactive Microcomputer Program for Education.

    ERIC Educational Resources Information Center

    Boyle, Joseph

    1985-01-01

    RESPSYST is a computer program (written in BASICA and using MS-DOS/PC-DOS microcomputers) incorporating more than 20 of the factors that determine gas transport by the cardio-respiratory system. The five-part program discusses most of these factors, provides several question/answer sections, and relies heavily on graphics to demonstrate…

  7. Microcomputer Courseware: Characteristics and Design Trends.

    ERIC Educational Resources Information Center

    Bialo, Ellen R.; Erickson, Lisa B.

    A total of 163 microcomputer programs evaluated by the Educational Products Information Exchange (EPIE) Institute through December 1983 were examined in order to identify strengths and weaknesses in instructional and technical design. Programs were evaluated in a variety of areas including the arts, business education, computer languages, computer…

  8. Comparison of different numerical treatments for x-ray phase tomography of soft tissue from differential phase projections

    NASA Astrophysics Data System (ADS)

    Pelliccia, Daniele; Vaz, Raquel; Svalbe, Imants; Morgan, Kaye S.; Marathe, Shashidhara; Xiao, Xianghui; Assoufid, Lahsen; Anderson, Rebecca A.; Topczewski, Jacek; Bryson-Richardson, Robert J.

    2015-04-01

    X-ray imaging of soft tissue is made difficult by their low absorbance. The use of x-ray phase imaging and tomography can significantly enhance the detection of these tissues and several approaches have been proposed to this end. Methods such as analyzer-based imaging or grating interferometry produce differential phase projections that can be used to reconstruct the 3D distribution of the sample refractive index. We report on the quantitative comparison of three different methods to obtain x-ray phase tomography with filtered back-projection from differential phase projections in the presence of noise. The three procedures represent different numerical approaches to solve the same mathematical problem, namely phase retrieval and filtered back-projection. It is found that obtaining individual phase projections and subsequently applying a conventional filtered back-projection algorithm produces the best results for noisy experimental data, when compared with other procedures based on the Hilbert transform. The algorithms are tested on simulated phantom data with added noise and the predictions are confirmed by experimental data acquired using a grating interferometer. The experiment is performed on unstained adult zebrafish, an important model organism for biomedical studies. The method optimization described here allows resolution of weak soft tissue features, such as muscle fibers.

  9. Comparison between diffraction contrast tomography and high-energy diffraction microscopy on a slightly deformed aluminium alloy

    PubMed Central

    Renversade, Loïc; Quey, Romain; Ludwig, Wolfgang; Menasche, David; Maddali, Siddharth; Suter, Robert M.; Borbély, András

    2016-01-01

    The grain structure of an Al–0.3 wt%Mn alloy deformed to 1% strain was reconstructed using diffraction contrast tomography (DCT) and high-energy diffraction microscopy (HEDM). 14 equally spaced HEDM layers were acquired and their exact location within the DCT volume was determined using a generic algorithm minimizing a function of the local disorientations between the two data sets. The microstructures were then compared in terms of the mean crystal orientations and shapes of the grains. The comparison shows that DCT can detect subgrain boundaries with disorientations as low as 1° and that HEDM and DCT grain boundaries are on average 4 µm apart from each other. The results are important for studies targeting the determination of grain volume. For the case of a polycrystal with an average grain size of about 100 µm, a relative deviation of about ≤10% was found between the two techniques. PMID:26870379

  10. Comparison between diffraction contrast tomography and high-energy diffraction microscopy on a slightly deformed aluminium alloy.

    PubMed

    Renversade, Loïc; Quey, Romain; Ludwig, Wolfgang; Menasche, David; Maddali, Siddharth; Suter, Robert M; Borbély, András

    2016-01-01

    The grain structure of an Al-0.3 wt%Mn alloy deformed to 1% strain was reconstructed using diffraction contrast tomography (DCT) and high-energy diffraction microscopy (HEDM). 14 equally spaced HEDM layers were acquired and their exact location within the DCT volume was determined using a generic algorithm minimizing a function of the local disorientations between the two data sets. The microstructures were then compared in terms of the mean crystal orientations and shapes of the grains. The comparison shows that DCT can detect subgrain boundaries with disorientations as low as 1° and that HEDM and DCT grain boundaries are on average 4 µm apart from each other. The results are important for studies targeting the determination of grain volume. For the case of a polycrystal with an average grain size of about 100 µm, a relative deviation of about ≤10% was found between the two techniques.

  11. Comparison between diffraction contrast tomography and high-energy diffraction microscopy on a slightly deformed aluminium alloy.

    PubMed

    Renversade, Loïc; Quey, Romain; Ludwig, Wolfgang; Menasche, David; Maddali, Siddharth; Suter, Robert M; Borbély, András

    2016-01-01

    The grain structure of an Al-0.3 wt%Mn alloy deformed to 1% strain was reconstructed using diffraction contrast tomography (DCT) and high-energy diffraction microscopy (HEDM). 14 equally spaced HEDM layers were acquired and their exact location within the DCT volume was determined using a generic algorithm minimizing a function of the local disorientations between the two data sets. The microstructures were then compared in terms of the mean crystal orientations and shapes of the grains. The comparison shows that DCT can detect subgrain boundaries with disorientations as low as 1° and that HEDM and DCT grain boundaries are on average 4 µm apart from each other. The results are important for studies targeting the determination of grain volume. For the case of a polycrystal with an average grain size of about 100 µm, a relative deviation of about ≤10% was found between the two techniques. PMID:26870379

  12. Comparison Between Perfusion Computed Tomography and Dynamic Contrast-Enhanced Magnetic Resonance Imaging in Rectal Cancer

    SciTech Connect

    Kierkels, Roel G.J.; Backes, Walter H.; Janssen, Marco H.M.; Buijsen, Jeroen; Beets-Tan, Regina G.H.; Lambin, Philippe; Lammering, Guido; Oellers, Michel C.; Aerts, Hugo J.W.L.

    2010-06-01

    Purpose: To compare pretreatment scans with perfusion computed tomography (pCT) vs. dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in rectal tumors. Methods and Materials: Nineteen patients diagnosed with rectal cancer were included in this prospective study. All patients underwent both pCT and DCE-MRI. Imaging was performed on a dedicated 40-slice CT-positron emission tomography system and a 3-T MRI system. Dynamic contrast enhancement was measured in tumor tissue and the external iliac artery. Tumor perfusion was quantified in terms of pharmacokinetic parameters: transfer constant K{sup trans}, fractional extravascular-extracellular space v{sub e}, and fractional plasma volume v{sub p}. Pharmacokinetic parameter values and their heterogeneity (by 80% quantile value) were compared between pCT and DCE-MRI. Results: Tumor K{sup trans} values correlated significantly for the voxel-by-voxel-derived median (Kendall's tau correlation, tau = 0.81, p < 0.001) and 80% quantile (tau = 0.54, p = 0.04), as well as for the averaged uptake (tau = 0.58, p = 0.03). However, no significant correlations were found for v{sub e} and v{sub p} derived from the voxel-by-voxel-derived median and 80% quantile and derived from the averaged uptake curves. Conclusions: This study demonstrated for the first time that pCT provides K{sup trans} values comparable to those of DCE-MRI. However, no correlation was found for the v{sub e} and v{sub p} parameters between CT and MRI. Computed tomography can serve as an alternative modality to MRI for the in vivo evaluation of tumor angiogenesis in terms of the transfer constant K{sup trans}.

  13. A comparison of in-house and regionalized computerized tomography scanning: clinical impact and cost.

    PubMed Central

    Elixhauser, A; Reker, D M; Gillespie, K N; Fletcher, J; Wolinsky, F D

    1990-01-01

    Over a two-year interval, computerized tomography (CT) scans at an urban, 400-bed Department of Veterans Affairs medical center (VAMC) were obtained in three ways. First, an in-house low-efficiency machine was used. Then, scans were done at another area hospital, in effect duplicating some aspects of regionalizing services. Finally, a high-efficiency in-house machine was used. Clinical outcomes and costs of diagnosing 181 bronchogenic cancer patients were compared across the three time periods to identify any differences associated with regionalization of CT services. Patient groups were homogeneous with respect to sociodemographic characteristics, clinical presentation, and severity of disease. The first part of the analysis investigated whether the site of CT scanning affected clinical outcomes. Diagnostic procedures, surgical results, mortality, and length of stay were compared using one-way analysis of variance. Significant differences were found only for conventional tomography and CT utilization rates. While conventional tomography declined across the periods, CT utilization increased, exceeding national trends. The second part of the analysis examined the costs of CT scanning. During the regionalized period, the hospital paid a fixed fee of $519 per scan. Estimated costs of in-house scans were $285 in the low-efficiency and $141 in the high-efficiency periods. Charge-based payments made to the external facility and differences in the volumes of patients scanned internally account for the cost differences. The analysis showed that while regionalized CT scanning did not compromise the quality of care for these VA patients, it was more costly. Results suggest that VA hospital administrators should carefully consider ownership and payment arrangements when comparing regionalized and in-house provision of services. PMID:2109740

  14. Comparison of Spall Pullback Signals and X-ray Tomography Analysis in Copper

    NASA Astrophysics Data System (ADS)

    Gard, Marcie; Russell, Rod; Hanna, Romy; Bless, Stephan; InstituteAdvanced Technology Collaboration; Department of Geological Sciences-UT Austin Collaboration

    2011-06-01

    Spall experiments were conducted on electrolytic tough pitch C110 copper plates. Flyer plates half the target-plate thickness were launched with a single-stage compressed-gas gun. Pullback signals were measured with a photonic Doppler velocimeter (PDV). Spall stresses were determined and found to be about 1 GPa. In addition, damage on the spall plane for samples that failed to separate a spall plate was characterized by x-ray tomography. The paper will include a description of threshold damage. The threshold for appearance of a pullback signal corresponded to the initiation of tensile damage, not formation of a spall separation plane.

  15. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    NASA Astrophysics Data System (ADS)

    Beasley, D. G.; Alves, L. C.; Barberet, Ph.; Bourret, S.; Devès, G.; Gordillo, N.; Michelet, C.; Le Trequesser, Q.; Marques, A. C.; Seznec, H.; da Silva, R. C.

    2014-07-01

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans - a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

  16. Comparison of algorithms for non-linear inverse 3D electrical tomography reconstruction.

    PubMed

    Molinari, Marc; Cox, Simon J; Blott, Barry H; Daniell, Geoffrey J

    2002-02-01

    Non-linear electrical impedance tomography reconstruction algorithms usually employ the Newton-Raphson iteration scheme to image the conductivity distribution inside the body. For complex 3D problems, the application of this method is not feasible any more due to the large matrices involved and their high storage requirements. In this paper we demonstrate the suitability of an alternative conjugate gradient reconstruction algorithm for 3D tomographic imaging incorporating adaptive mesh refinement and requiring less storage space than the Newton-Raphson scheme. We compare the reconstruction efficiency of both algorithms for a simple 3D head model. The results show that an increase in speed of about 30% is achievable with the conjugate gradient-based method without loss of accuracy.

  17. Renal trauma: radiological studies - comparison of urography, computed tomography, angiography, and radionuclide studies

    SciTech Connect

    Lang, E.K.; Sullivan, J.; Frentz, G.

    1985-01-01

    Excretory urography, computed radionuclide urography, angiography, and both conventional and dynamic computed tomography (CT) were compared with regard to accuracy, sensitivity, and specificity in 388 patients with renal trauma. Used as the triage examination, urography established the absence of significant renal injury with an accuracy of 87%, obviating further evaluation. Dynamic CT proved to be the best methods of assessing parenchymal injuries, establishing the correct diagnosis in 129 out of 130 cases compared to 116/130 for conventional CT. Angiography was the procedure of choice for diagnosis and categorization of renal artery injuries, which were diagnosed correctly in all 43 cases. The choice between dynamic CT and angiography as the second examination rests upon careful evaluation of clinical and urographic findings for signs of renal artery injury which would mandate angiographic assessment.

  18. Magnetic resonance imaging of the adrenal glands: a comparison with computed tomography

    SciTech Connect

    Schultz, C.L.; Haaga, J.R.; Fletcher, B.D.; Alfidi, R.J.; Schultz, M.A.

    1984-12-01

    This investigation compared magnetic resonance imaging (MRI) with computed tomography (CT) in the evaluation of normal and abnormal adrenal glands. Thirty normal volunteers were studied with MRI, and the results were compared with a retrospective review of 30 normal CT examinations. CT identified both adrenal glands in all 30 patients. MRI identified both glands in 29 of 30 volunteers. There were no statistically significant differences between the two imaging techniques using chi-square analysis. Twenty-one patients with abnormal adrenal gland(s) detected with CT were also studied with MRI. The abnormalities studied included bilateral hyperplasia (three patients), adenoma (two), myelolipoma (one), adrenal metastases (six), adrenal hemorrhage (two), and neuroblastoma (seven). MRI detected the abnormal adrenal gland(s) in 20 of 21 patients. The CT and MRI features of the adrenal lesions are discussed.

  19. A comparison of the redistribution and reinjection techniques in dipyridamole thallium tomography.

    PubMed

    Kennedy, N S; Cook, B; Choy, A M; Bridges, A B; Hanson, J K; McNeill, G P; Pringle, T H

    1993-06-01

    The effect of the injection of additional thallium after a redistribution study and prior to a further resting study was evaluated in 21 patients with angiographically proven coronary artery disease. Using dipyridamole as the stress mechanism, the studies were carried out tomographically and the results analysed quantitatively with the Bull's-eye technique. Two patients had normal scans. Of the remaining 19, 11 patients had a perfusion defect which appeared irreversible on redistribution imaging. However, six of these patients demonstrated improved or normal uptake after the second injection of thallium. Of the eight patients with a reversible defect, two revealed considerably greater reversibility after reinjection. These results indicate that the reinjection of thallium prior to the resting study significantly (P < 0.02) improves the detection rate of ischaemia during dipyridamole thallium tomography.

  20. A quantitative spatial comparison of high-density diffuse optical tomography and fMRI cortical mapping

    PubMed Central

    Eggebrecht, Adam T.; White, Brian R.; Ferradal, Silvina L.; Chen, Chunxiao; Zhan, Yuxuan; Snyder, Abraham Z.; Dehghani, Hamid; Culver, Joseph P.

    2012-01-01

    Functional neuroimaging commands a dominant role in current neuroscience research. However its use in bedside clinical and certain neuro-scientific studies has been limited because the current tools lack the combination of being non-invasive, non-ionizing and portable while maintaining moderate resolution and localization accuracy. Optical neuroimaging satisfies many of these requirements, but, until recent advances in high-density diffuse optical tomography (HD-DOT), has been hampered by limited resolution. While early results of HD-DOT have been promising, a quantitative voxel-wise comparison and validation of HD-DOT against the gold standard of functional magnetic resonance imaging (fMRI) has been lacking. Herein, we provide such an analysis within the visual cortex using matched visual stimulation protocols in a single group of subjects (n=5) during separate HD-DOT and fMRI scanning sessions. To attain the needed voxel-to-voxel co-registration between HD-DOT and fMRI image spaces, we implemented subject-specific head modeling that incorporated MRI anatomy, detailed segmentation, and alignment of source and detector positions. Comparisons of the visual responses found an average localization error between HD-DOT and fMRI of 4.4 +/− 1 mm, significantly less than the average distance between cortical gyri. This specificity demonstrates that HD-DOT has sufficient image quality to be useful as a surrogate for fMRI. PMID:22330315

  1. Comparison of Two Algorithms for Analysis of Perfusion Computed Tomography Data for Evaluation of Cerebral Microcirculation in Chronic Subdural Hematoma.

    PubMed

    Trofimov, Alexey O; Kalentiev, George; Voennov, Oleg; Yuriev, Michail; Agarkova, Darya; Trofimova, Svetlana; Bragin, Denis E

    2016-01-01

    The aim of this work was comparison of two algorithms of perfusion computed tomography (PCT) data analysis for evaluation of cerebral microcirculation in the perifocal zone of chronic subdural hematoma (CSDH). Twenty patients with CSDH after polytrauma were included in the study. The same PCT data were assessed quantitatively in cortical brain region beneath the CSDH (zone 1), and in the corresponding contralateral brain hemisphere (zone 2) without and with the use of perfusion calculation mode excluding vascular pixel 'Remote Vessels' (RV); 1st and 2nd analysis method, respectively. Comparison with normal values for perfusion indices in the zone 1 in the 1st analysis method showed a significant (p < 0.01) increase in CBV and CBF, and no significant increase in MTT and TTP. Use of the RV mode (2nd analysis method) showed no statistically reliable change of perfusion parameters in the microcirculatory blood flow of the 2nd zone. Maintenance of microcirculatory blood flow perfusion reflects the preservation of cerebral blood flow autoregulation in patients with CSDH. PMID:27526170

  2. The Effect of Experimental Variables on Industrial X-Ray Micro-Computed Sensitivity

    NASA Technical Reports Server (NTRS)

    Roth, Don J.; Rauser, Richard W.

    2014-01-01

    A study was performed on the effect of experimental variables on radiographic sensitivity (image quality) in x-ray micro-computed tomography images for a high density thin wall metallic cylinder containing micro-EDM holes. Image quality was evaluated in terms of signal-to-noise ratio, flaw detectability, and feature sharpness. The variables included: day-to-day reproducibility, current, integration time, voltage, filtering, number of frame averages, number of projection views, beam width, effective object radius, binning, orientation of sample, acquisition angle range (180deg to 360deg), and directional versus transmission tube.

  3. Printed circuit board layout by microcomputer

    NASA Astrophysics Data System (ADS)

    Krausman, E. W.

    1983-12-01

    Printed circuit board artwork is usually prepared manually because of the unavailability of computer-aided-design tools. This thesis presents the design of a microcomputer based printed circuit board layout system that is easy to use and cheap. Automatic routing and component placement routines will significantly speed up the process. The design satisfies the following requirements: Microcomputer implementation, portable, algorithm independent, interactive, and user friendly. When it is fully implemented a user will be able to select components and a board outline from an automated catalog, enter a schematic diagram, position the components on the board, and completely route the board from a single graphics terminal. Currently, the user interface and the outer level command processor have been implemented in Pascal. Future versions will be written in C for better portability.

  4. Versatile microcomputer-based temperature controller

    SciTech Connect

    Yarberry, V.R.

    1980-09-01

    The wide range of thermal responses required in laboratory and scientific equipment requires a temperature controller with a great deal of flexibility. While a number of analog temperature controllers are commercially available, they have certain limitations, such as inflexible parameter control or insufficient precision. Most lack digital interface capabilities--a necessity when the temperature controller is part of a computer-controlled automatic data acquisition system. We have developed an extremely versatile microcomputer-based temperature controller to fulfill this need in a variety of equipment. The control algorithm used allows optimal tailoring of parameters to control overshoot, response time, and accuracy. This microcomputer-based temperature controller can be used as a standalone instrument (with a teletype used to enter para-meters), or it can be integrated into a data acquisition system (with a computer used to pass parameters by way of an IEE-488 instrumentation bus).

  5. Scheduling nursing personnel on a microcomputer.

    PubMed

    Liao, C J; Kao, C Y

    1997-01-01

    Suggests that with the shortage of nursing personnel, hospital administrators have to pay more attention to the needs of nurses to retain and recruit them. Also asserts that improving nurses' schedules is one of the most economic ways for the hospital administration to create a better working environment for nurses. Develops an algorithm for scheduling nursing personnel. Contrary to the current hospital approach, which schedules nurses on a person-by-person basis, the proposed algorithm constructs schedules on a day-by-day basis. The algorithm has inherent flexibility in handling a variety of possible constraints and goals, similar to other non-cyclical approaches. But, unlike most other non-cyclical approaches, it can also generate a quality schedule in a short time on a microcomputer. The algorithm was coded in C language and run on a microcomputer. The developed software is currently implemented at a leading hospital in Taiwan. The response to the initial implementation is quite promising. PMID:10167872

  6. A Microcomputer-Based Neurophysiological Stimulator

    PubMed Central

    Halter, John

    1979-01-01

    A neurophysiological stimulator is presented which utilizes TTL hardware controlled by a microcomputer. Up to four channels of stimulation are provided, each of which consists of a TTL-Based Pulse Generator. Operating parameters are entered into the stimulator via a front panel in a format familiar to the clinician. Operating parameters may be investigated and modified at any time by another computer, thereby enabling the implementation of more complex clinical procedures. ImagesFigure 1Figure 4

  7. Some Applications of Microcomputers in Observatory Automation

    NASA Astrophysics Data System (ADS)

    Honeycutt, R. K.; Kephart, J. E.

    1982-06-01

    We present here some of the techniques used to automate many of the observing tasks on the 0.91-meter telescope of the Goethe Link Observatory. A description of the method used to calculate the dome position for a telescope which is mounted asymmetrically is included. We also give details of a novel autoguider. This autoguider uses a digitized television image of the star field to enable the microcomputer to generate error signals from a centroid calculation.

  8. Federal microcomputer software for urban hydrology

    USGS Publications Warehouse

    Jennings, Marshall E.; Smith, Roger H.; Jennings, Ross B.

    1988-01-01

    The purpose of this paper is to describe the development, availability, and general use of selected urban hydrology microcomputer software developed by: U.S. Soil Conservation Service (SCS); U.S. Army Corps of Engineers, Hydrologic Engineering Center (HEC); U.S. Environmental Protection Agency (EPA); and U.S. Geological Survey (USGS). The discussion is limited to software used for design and planning for urban stormwater flows.

  9. Accessing remote data bases using microcomputers

    PubMed Central

    Saul, Peter D.

    1985-01-01

    General practitioners' access to remote data bases using microcomputers is increasing, making even the most obscure information readily available. Some of the systems available to general practitioners in the UK are described and the methods of access are outlined. General practitioners should be aware of the advances in technology; data bases are increasing in size, the cost of access is falling and their use is becoming easier. PMID:4020756

  10. Experimental Comparison of Continuous-Wave and Frequency-Domain Fluorescence Tomography in a Commercial Multi-Modal Scanner.

    PubMed

    Lu, Yujie; Darne, Chinmay D; Tan, I-Chih; Zhu, Banghe; Rightmer, Ryan; Rasmussen, John C; Sevick-Muraca, Eva M

    2015-06-01

    The performance evaluation of a variety of small animal tomography measurement approaches and algorithms for recovery of fluorescent absorption cross section has not been conducted. Herein, we employed an intensified CCD system installed in a commercial small animal CT (Computed Tomography) scanner to compare image reconstructions from time-independent, continuous wave (CW) measurements and from time-dependent, frequency domain (FD) measurements in a series of physical phantoms specifically designed for evaluation. Comparisons were performed as a function of (1) number of projections, (2) the level of preprocessing filters used to improve the signal-to-noise ratio (SNR), (3) endogenous heterogeneity of optical properties, as well as in the cases of (4) two fluorescent targets and (5) a mouse-shaped phantom. Assessment of quantitative recovery of fluorescence absorption cross section was performed using a fully parallel, regularization-free, linear reconstruction algorithm with diffusion approximation (DA) and high order simplified spherical harmonics ( SPN) approximation to the radiative transport equation (RTE). The results show that while FD measurements may result in superior image reconstructions over CW measurements, data acquisition times are significantly longer, necessitating further development of multiple detector/source configurations, improved data read-out rates, and detector technology. FD measurements with SP3 reconstructions enabled better quantitative recovery of fluorescent target strength, but required increased computational expense. Despite the developed parallel reconstruction framework being able to achieve more than 60 times speed increase over sequential implementation, further development in faster parallel acceleration strategies for near-real time and real-time image recovery and more precise forward solution is necessary. PMID:25438307

  11. Comparison of rubidium-82 positron emission tomography and thallium-201 SPECT imaging for detection of coronary artery disease

    SciTech Connect

    Stewart, R.E.; Schwaiger, M.; Molina, E.; Popma, J.; Gacioch, G.M.; Kalus, M.; Squicciarini, S.; al-Aouar, Z.R.; Schork, A.; Kuhl, D.E. )

    1991-06-15

    The diagnostic performance of rubidium-82 (Rb-82) positron emission tomography (PET) and thallium-201 (Tl-201) single-photon emission-computed tomography (SPECT) for detecting coronary artery disease was investigated in 81 patients (52 men, 29 women). PET studies using 60 mCi of Rb-82 were performed at baseline and after intravenous infusion of 0.56 mg/kg dipyridamole in conjunction with handgrip stress. Tl-201 SPECT was performed after dipyridamole-handgrip stress and, in a subset of patients, after treadmill exercise. Sensitivity, specificity and overall diagnostic accuracy were assessed using both visually and quantitatively interpreted coronary angiograms. The overall sensitivity, specificity and accuracy of PET for detection of coronary artery disease (greater than 50% diameter stenosis) were 84, 88 and 85%, respectively. In comparison, the performance of SPECT revealed a sensitivity of 84%, specificity of 53% (p less than 0.05 vs PET) and accuracy of 79%. Similar results were obtained using either visual or quantitative angiographic criteria for severity of coronary artery disease. In 43 patients without prior myocardial infarction, the sensitivity for detection of disease was 71 and 73%, respectively, similar for both PET and SPECT. There was no significant difference in diagnostic performance between imaging modalities when 2 different modes of stress (exercise treadmill vs intravenous dipyridamole plus handgrip) were used with SPECT imaging. Thus, Rb-82 PET provides improved specificity compared with Tl-201 SPECT for identifying coronary artery disease, most likely due to the higher photon energy of Rb-82 and attenuation correction provided by PET. However, post-test referral cannot be entirely excluded as a potential explanation for the lower specificity of Tl-201 SPECT.

  12. Comparison of magmatic structures beneath Redoubt (Alaska) and Toba (Northern Sumatra) volcanoes derived from local earthquake tomography studies

    NASA Astrophysics Data System (ADS)

    Kasatkina, Ekaterina; Koulakov, Ivan; West, Michael

    2014-05-01

    We present the results of seismic tomography studies of two different volcanoes - Mt. Redoubt and Toba caldera. These two subduction related volcanoes have different ages and scales of eruption activity. Velocity model beneath the Redoubt volcano is based on tomographic inversion of P- and S- arrival time data from over 4000 local earthquakes recorded by 19 stations since 1989 to 2012 provided by the Alaskan Volcano Observatory (University of Fairbanks). Just below the volcano edifice we observe an anomaly of high Vp/Vs ratio reaching 2.2 which is seen down to 2- 3 km depth. This indicates a presence of partially molten substance or fluid filled rocks. We can suggest that anomaly area matches with volcano magma chamber. One of the previous velocity models of Toba caldera was obtained by Koulakov et al. (2009) and was based on data recorded by temporary network from January to May 1995. In this study this "old" dataset was supplemented with "new" data recorded by a temporary network deployed in approximately same area by GFZ-Potsdam from May to November 2008. We have manually picked the arrival times from the local events recorded by the later experiment and then performed the tomography inversion for the combined dataset using the LOTOS code (Koulakov, 2009). In the uppermost layers we observe strong low-velocity P- and S- anomalies within the Caldera which can be interpreted by the presence of think sediments filling the caldera. In the lower crust and uppermost mantle we observe a vertical anomaly of low P- and S-velocities which probably represent the path of conduits which link the caldera area with the slab. Similar to Redoubt volcano, resulting velocity model of Toba has an increased value of Vp/Vs ratio that indicates a presence of magma reservoir. Comparison of the tomographic results obtained for the completely different volcanic systems helps in understanding some basic principles of feeding the volcanoes. This study was partly supported by the Project #7

  13. Comparison of Ultrahigh- and Standard-Resolution Optical Coherence Tomography for Imaging Macular Hole Pathology and Repair

    PubMed Central

    Ko, Tony H.; Fujimoto, James G.; Duker, Jay S.; Paunescu, Lelia A.; Drexler, Wolfgang; Baumal, Caroline R.; Puliafito, Carmen A.; Reichel, Elias; Rogers, Adam H.; Schuman, Joel S.

    2007-01-01

    of the macular hole architectural morphology. The increased resolution of UHR-OCT enables the visualization of photoreceptor morphology associated with macular holes. This promises to lead to a better understanding of the pathogenesis of macular holes, the causes of visual loss secondary to macular holes, the timing of surgical repair, and the evaluation of postsurgical outcome. Ultrahigh-resolution optical coherence tomography imaging of macular holes that correspond to known alterations in retinal morphology can be used to interpret retinal morphology in UHR-OCT images. Comparisons of UHR-OCT images with standard-resolution OCT images can establish a baseline for the better interpretation of clinical standard-resolution OCT images. The ability to visualize photoreceptors and their integrity or impairment is an indicator of macular hole progression and surgical outcome. PMID:15522369

  14. Microcomputers in exploration - perspective and forecast

    SciTech Connect

    Crane, D.C.

    1984-04-01

    General purpose microcomputers have become so inexpensive that powerful systems now are within the budget of a one-person company. The uninitiated have visions of a desktop machine that can do budget reports, royalty accounting, lease control, interactive modeling of the subsurface, contour maps, decision making, dart throwing, and much more. Old hands in major oil companies can see the opposite side: horror stories about expensive programming projects, machines that are overloaded and slow, and enormous staffs required to interface the working geologist with the machine. The truth about microcomputers is somewhere in between. An intelligent search for software packages will turn up a few that pay for themselves and the computer(s) they require. But buying a machine and attempting to make it fit a ''grand vision'' can lead to disaster. This paper presents a perspective on microcomputer capabilities, both software and hardware, now and for the next few years, and suggests a method and a schedule for small-company geologists to become involved with computers.

  15. Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study.

    PubMed

    Oliver, Josep F; Rafecas, M

    2016-01-01

    Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, "Singles-Prompts" (SP), that includes the information conveyed by prompt coincidences and models the pile-up. The SP method has the same structure than the well-known "Singles Rate" (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte-Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (∼10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, +16%, while SP produces the correct value. Spill-over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, -16%. In general, the better estimations of SP translate into better image quality. PMID:27603143

  16. Modelling Random Coincidences in Positron Emission Tomography by Using Singles and Prompts: A Comparison Study

    PubMed Central

    2016-01-01

    Random coincidences degrade the image in Positron Emission Tomography, PET. To compensate for their degradation effects, the rate of random coincidences should be estimated. Under certain circumstances, current estimation methods fail to provide accurate results. We propose a novel method, “Singles–Prompts” (SP), that includes the information conveyed by prompt coincidences and models the pile–up. The SP method has the same structure than the well-known “Singles Rate” (SR) approach. Hence, SP can straightforwardly replace SR. In this work, the SP method has been extensively assessed and compared to two conventional methods, SR and the delayed window (DW) method, in a preclinical PET scenario using Monte–Carlo simulations. SP offers accurate estimates for the randoms rates, while SR and DW tend to overestimate the rates (∼10%, and 5%, respectively). With pile-up, the SP method is more robust than SR (but less than DW). At the image level, the contrast is overestimated in SR-corrected images, +16%, while SP produces the correct value. Spill–over is slightly reduced using SP instead of SR. The DW images values are similar to those of SP except for low-statistic scenarios, where DW behaves as if randoms were not compensated for. In particular, the contrast is reduced, −16%. In general, the better estimations of SP translate into better image quality. PMID:27603143

  17. Methods and algorithms for optical coherence tomography-based angiography: a review and comparison

    NASA Astrophysics Data System (ADS)

    Zhang, Anqi; Zhang, Qinqin; Chen, Chieh-Li; Wang, Ruikang K.

    2015-10-01

    Optical coherence tomography (OCT)-based angiography is increasingly becoming a clinically useful and important imaging technique due to its ability to provide volumetric microvascular networks innervating tissue beds in vivo without a need for exogenous contrast agent. Numerous OCT angiography algorithms have recently been proposed for the purpose of contrasting microvascular networks. A general literature review is provided on the recent progress of OCT angiography methods and algorithms. The basic physics and mathematics behind each method together with its contrast mechanism are described. Potential directions for future technical development of OCT based angiography is then briefly discussed. Finally, by the use of clinical data captured from normal and pathological subjects, the imaging performance of vascular networks delivered by the most recently reported algorithms is evaluated and compared, including optical microangiography, speckle variance, phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping. It is found that the method that utilizes complex OCT signal to contrast retinal blood flow delivers the best performance among all the algorithms in terms of image contrast and vessel connectivity. The purpose of this review is to help readers understand and select appropriate OCT angiography algorithm for use in specific applications.

  18. Comparison of two regularization methods for soft x-ray tomography at Tore Supra

    NASA Astrophysics Data System (ADS)

    Jardin, A.; Mazon, D.; Bielecki, J.

    2016-04-01

    Soft x-ray (SXR) emission in the range 0.1-20 keV is widely used to obtain valuable information on tokamak plasma physics, such as particle transport, magnetic configuration or magnetohydrodynamic activity. In particular, 2D tomography is the usual plasma diagnostic to access the local SXR emissivity. The tomographic inversion is traditionally performed from line-integrated measurements of two or more cameras viewing the plasma in a poloidal cross-section, like at Tore Supra (TS). Unfortunately, due to the limited number of measured projections and presence of noise, the tomographic reconstruction of SXR emissivity is a mathematical ill-posed problem. Thus, obtaining reliable results of the tomographic inversion is a very challenging task. In order to perform the reconstruction, inversion algorithms implemented in present tokamaks use a priori information as additional constraints imposed on the plasma SXR emissivity. Among several potential inversion methods, some of them have been identified as well suited to tokamak plasmas. The purpose of this work is to compare two promising inversion methods, i.e. the minimum fisher information method already used at TS and planned for WEST configuration, and the alternative 2nd order Phillips-Tikhonov regularization with smoothness constraints imposed on the second derivative norm. Respective accuracy of both reconstruction methods as well as overall robustness and computational time are studied, using several synthetic SXR emissivity profiles. Finally, a real case is studied through tomographic reconstruction from TS SXR database.

  19. GPS ionospheric tomography: A comparison with the IRI-2001 model over South Korea

    NASA Astrophysics Data System (ADS)

    Jin, S.; Park, J.-U.

    2007-04-01

    The International Reference Ionosphere model 2001 (IRI-2001) is one of the most comprehensive empirical models of the ionosphere and has been widely used to estimate the electron density profiles in the altitude ranging from about 60 to 2000 km and the total electron content (TEC) at any given location, time and date, which reflect smooth-average global ionospheric behaviors. However, whether it provides normal actual estimations in the ionosphere over some regions should be tested with real observation data. In this paper, the three-dimensional ionospheric electron density profiles over South Korea in 2003 are obtained using the ionospheric tomography reconstruction technique with the permanent Korean GPS Network (KGN) data, and its validity is further verified by another independent ionosonde data. The GPS ionospheric reconstruction results are used to compare then results obtained with the IRI-2001 model in South Korea in terms of NmF2 and TEC. The monthly averaged diurnal values of these key parameters in January, April, July and October 2003 are considered to represent the winter, spring, summer and autumn seasons, respectively. Compared with the GPS reconstruction results, averaged monthly NmF2 medians from the IRI-2001 are overestimated in daytime and underestimated in nighttime for all seasons, but the deviation magnitudes in autumn and winter are smaller than in spring and summer. In addition, averaged monthly TEC medians from the IRI-2001 are overestimated in daytime in winter, but almost always underestimated in other seasons.

  20. Methods and algorithms for optical coherence tomography-based angiography: a review and comparison

    PubMed Central

    Zhang, Anqi; Zhang, Qinqin; Chen, Chieh-Li; Wang, Ruikang K.

    2015-01-01

    Abstract. Optical coherence tomography (OCT)-based angiography is increasingly becoming a clinically useful and important imaging technique due to its ability to provide volumetric microvascular networks innervating tissue beds in vivo without a need for exogenous contrast agent. Numerous OCT angiography algorithms have recently been proposed for the purpose of contrasting microvascular networks. A general literature review is provided on the recent progress of OCT angiography methods and algorithms. The basic physics and mathematics behind each method together with its contrast mechanism are described. Potential directions for future technical development of OCT based angiography is then briefly discussed. Finally, by the use of clinical data captured from normal and pathological subjects, the imaging performance of vascular networks delivered by the most recently reported algorithms is evaluated and compared, including optical microangiography, speckle variance, phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping. It is found that the method that utilizes complex OCT signal to contrast retinal blood flow delivers the best performance among all the algorithms in terms of image contrast and vessel connectivity. The purpose of this review is to help readers understand and select appropriate OCT angiography algorithm for use in specific applications. PMID:26473588

  1. Comparison of rotational imaging optical coherence tomography and selective plane illumination microscopy for embryonic study

    NASA Astrophysics Data System (ADS)

    Wu, Chen; Ran, Shihao; Le, Henry H.; Singh, Manmohan; Larina, Irina V.; Mayerich, David; Dickinson, Mary E.; Larin, Kirill V.

    2016-03-01

    The mouse is a common model for studying developmental diseases. Different optical techniques have been developed to investigate mouse embryos, but each has its own set of limitations and restrictions. In this study, we imaged the same E9.5 mouse embryo with rotational imaging Optical Coherence Tomography (RI-OCT) and Selective Plane Illumination Microscopy (SPIM), and compared the two techniques. Results demonstrate that both methods can provide images with micrometer-scale spatial resolution. The RI-OCT technique was developed to increase imaging depth of OCT by performing traditional OCT imaging at multiple sides and co-registering the images. In SPIM, optical sectioning is achieved by illuminating the sample with a sheet of light. In this study, the images acquired from both techniques are compared with each other to evaluate the benefits and drawbacks of each technique for embryonic imaging. Since 3D stacks can be obtained by SPIM from different angles by rotating the sample, it might be possible to build a hybrid setup of two imaging modalities to combine the advantages of each technique.

  2. Comparison of two regularization methods for soft x-ray tomography at Tore Supra

    NASA Astrophysics Data System (ADS)

    Jardin, A.; Mazon, D.; Bielecki, J.

    2016-04-01

    Soft x-ray (SXR) emission in the range 0.1–20 keV is widely used to obtain valuable information on tokamak plasma physics, such as particle transport, magnetic configuration or magnetohydrodynamic activity. In particular, 2D tomography is the usual plasma diagnostic to access the local SXR emissivity. The tomographic inversion is traditionally performed from line-integrated measurements of two or more cameras viewing the plasma in a poloidal cross-section, like at Tore Supra (TS). Unfortunately, due to the limited number of measured projections and presence of noise, the tomographic reconstruction of SXR emissivity is a mathematical ill-posed problem. Thus, obtaining reliable results of the tomographic inversion is a very challenging task. In order to perform the reconstruction, inversion algorithms implemented in present tokamaks use a priori information as additional constraints imposed on the plasma SXR emissivity. Among several potential inversion methods, some of them have been identified as well suited to tokamak plasmas. The purpose of this work is to compare two promising inversion methods, i.e. the minimum fisher information method already used at TS and planned for WEST configuration, and the alternative 2nd order Phillips–Tikhonov regularization with smoothness constraints imposed on the second derivative norm. Respective accuracy of both reconstruction methods as well as overall robustness and computational time are studied, using several synthetic SXR emissivity profiles. Finally, a real case is studied through tomographic reconstruction from TS SXR database.

  3. Comparison of breast density measurements made using ultrasound tomography and mammography

    NASA Astrophysics Data System (ADS)

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Krycia, Mark; Sherman, Mark E.; Boyd, Norman; Gierach, Gretchen L.

    2015-03-01

    Women with elevated mammographic percent density, defined as the ratio of fibroglandular tissue area to total breast area on a mammogram are at an increased risk of developing breast cancer. Ultrasound tomography (UST) is an imaging modality that can create tomographic sound speed images of a patient's breast, which can then be used to measure breast density. These sound speed images are useful because physical tissue density is directly proportional to sound speed. The work presented here updates previous results that compared mammographic breast density measurements with UST breast density measurements within an ongoing study. The current analysis has been expanded to include 158 women with negative digital mammographic screens who then underwent a breast UST scan. Breast density was measured for both imaging modalities and preliminary analysis demonstrated strong and positive correlations (Spearman correlation coefficient rs = 0.703). Additional mammographic and UST related imaging characteristics were also analyzed and used to compare the behavior of both imaging modalities. Results suggest that UST can be used among women with negative mammographic screens as a quantitative marker of breast density that may avert shortcomings of mammography.

  4. Methods and algorithms for optical coherence tomography-based angiography: a review and comparison.

    PubMed

    Zhang, Anqi; Zhang, Qinqin; Chen, Chieh-Li; Wang, Ruikang K

    2015-10-01

    Optical coherence tomography (OCT)-based angiography is increasingly becoming a clinically useful and important imaging technique due to its ability to provide volumetric microvascular networks innervating tissue beds in vivo without a need for exogenous contrast agent. Numerous OCT angiography algorithms have recently been proposed for the purpose of contrasting microvascular networks. A general literature review is provided on the recent progress of OCT angiography methods and algorithms. The basic physics and mathematics behind each method together with its contrast mechanism are described. Potential directions for future technical development of OCT based angiography is then briefly discussed. Finally, by the use of clinical data captured from normal and pathological subjects, the imaging performance of vascular networks delivered by the most recently reported algorithms is evaluated and compared, including optical microangiography, speckle variance,phase variance, split-spectrum amplitude decorrelation angiography, and correlation mapping. It is found that the method that utilizes complex OCT signal to contrast retinal blood flow delivers the best performance among all the algorithms in terms of image contrast and vessel connectivity. The purpose of this review is to help readers understand and select appropriate OCT angiography algorithm for use in specific applications.

  5. Comparison of Kasai Autocorrelation and Maximum Likelihood Estimators for Doppler Optical Coherence Tomography

    PubMed Central

    Chan, Aaron C.; Srinivasan, Vivek J.

    2013-01-01

    In optical coherence tomography (OCT) and ultrasound, unbiased Doppler frequency estimators with low variance are desirable for blood velocity estimation. Hardware improvements in OCT mean that ever higher acquisition rates are possible, which should also, in principle, improve estimation performance. Paradoxically, however, the widely used Kasai autocorrelation estimator’s performance worsens with increasing acquisition rate. We propose that parametric estimators based on accurate models of noise statistics can offer better performance. We derive a maximum likelihood estimator (MLE) based on a simple additive white Gaussian noise model, and show that it can outperform the Kasai autocorrelation estimator. In addition, we also derive the Cramer Rao lower bound (CRLB), and show that the variance of the MLE approaches the CRLB for moderate data lengths and noise levels. We note that the MLE performance improves with longer acquisition time, and remains constant or improves with higher acquisition rates. These qualities may make it a preferred technique as OCT imaging speed continues to improve. Finally, our work motivates the development of more general parametric estimators based on statistical models of decorrelation noise. PMID:23446044

  6. Comparison between multislice and cone-beam computerized tomography in the volumetric assessment of cleft palate.

    PubMed

    Albuquerque, Marco Antonio; Gaia, Bruno Felipe; Cavalcanti, Marcelo Gusmão Paraíso

    2011-08-01

    The aim of this study was to determine the applicability of multislice and cone-beam computerized tomography (CT) in the assessment of bone defects in patients with oral clefts. Bone defects were produced in 9 dry skulls to mimic oral clefts. All defects were modeled with wax. The skulls were submitted to multislice and cone-beam CT. Subsequently, physical measurements were obtained by the Archimedes principle of water displacement of wax models. The results demonstrated that multislice and cone-beam CT showed a high efficiency rate and were considered to be effective for volumetric assessment of bone defects. It was also observed that both CT modalities showed excellent results with high reliability in the study of the volume of bone defects, with no difference in performance between them. The clinical applicability of our research has shown these CT modalities to be immediate and direct, and they is important for the diagnosis and therapeutic process of patients with oral cleft. PMID:21664153

  7. COMPARISON OF COMPUTED TOMOGRAPHY AND ABDOMINAL RADIOGRAPHY FOR DETECTION OF CANINE MECHANICAL INTESTINAL OBSTRUCTION.

    PubMed

    Drost, Wm Tod; Green, Eric M; Zekas, Lisa J; Aarnes, Turi K; Su, Lillian; Habing, Gregory G

    2016-07-01

    Vomiting, often caused by mechanical intestinal obstruction, is common in dogs. Equivocal radiographic signs often necessitate repeat radiographs or additional imaging procedures. For our prospective, case-controlled, accuracy study, we hypothesized the following: (1) using computed tomography (CT), radiologists will be more sensitive and specific for detecting mechanical intestinal obstruction and recommending surgery compared to using radiographs; and (2) using measurements, radiologists will be more sensitive and specific using radiographs or CT for detecting mechanical intestinal obstruction and recommending surgery. Twenty dogs had abdominal radiographs and abdominal CT. Seventeen dogs had abdominal surgery and three dogs were not obstructed based on clinical follow-up. Confidence levels (five-point scale) of three experienced radiologists for mechanical intestinal obstruction and recommending surgery were recorded before and after making selected measurements. Eight dogs had surgically confirmed mechanical intestinal obstruction, and 12 dogs did not have obstruction. For detecting mechanical intestinal obstruction, CT was more sensitive (95.8% vs. 79.2%) and specific (80.6% vs. 69.4%) compared to radiographs, but the difference was not statistically significant. For recommending surgery, radiography was more sensitive (91.7% vs. 83.3%) and specific (83.3% vs. 72.2%) than using CT, but differences were not statistically significant. We reported objective CT measurements for predicting small mechanical intestinal obstruction. By incorporating these objective data, the diagnosis of mechanical intestinal obstruction changed in five of 120 instances (radiographs and CT). In no instance (0/120), did the objective data change the recommendation for surgery. Using CT or abdominal radiographs for the detection of canine mechanical intestinal obstruction is sensitive and specific when evaluated by experienced veterinary radiologists.

  8. Ultrasonography in the diagnosis of nasal bone fractures: a comparison with conventional radiography and computed tomography.

    PubMed

    Lee, In Sook; Lee, Jung-Hoon; Woo, Chang-Ki; Kim, Hak Jin; Sol, Yu Li; Song, Jong Woon; Cho, Kyu-Sup

    2016-02-01

    The purpose of this study was to evaluate and compare the diagnostic efficacy of ultrasonography (US) with radiography and multi-detector computed tomography (CT) for the detection of nasal bone fractures. Forty-one patients with a nasal bone fracture who underwent prospective US examinations were included. Plain radiographs and CT images were obtained on the day of trauma. For US examinations, radiologist used a linear array transducer (L17-5 MHz) in 24 patients and hockey-stick probe (L15-7 MHz) in 17. The bony component of the nose was divided into three parts (right and left lateral nasal walls, and midline of nasal bone). Fracture detection by three modalities was subjected to analysis. Furthermore, findings made by each modality were compared with intraoperative findings. Nasal bone fractures were located in the right lateral wall (n = 28), midline of nasal bone (n = 31), or left lateral wall (n = 31). For right and left lateral nasal walls, CT had greater sensitivity and specificity than US or radiography, and better agreed with intraoperative findings. However, for midline fractures of nasal bone, US had higher specificity, positive predictive value, and negative predictive value than CT. Although two US evaluations showed good agreements at all three sites, US findings obtained by the hockey-stick probe showed closer agreement with intraoperative findings for both lateral nasal wall and midline of nasal bone. Although CT showed higher sensitivity and specificity than US or radiography, US found to be helpful for evaluating the midline of nasal bone. Furthermore, for US examinations of the nasal bone, a smaller probe and higher frequency may be required.

  9. Optical Coherence Tomography Angiography in Mice: Comparison with Confocal Scanning Laser Microscopy and Fluorescein Angiography

    PubMed Central

    Giannakaki-Zimmermann, Helena; Kokona, Despina; Wolf, Sebastian; Ebneter, Andreas; Zinkernagel, Martin S.

    2016-01-01

    Purpose Optical coherence tomography angiography (OCT-A) allows noninvasive visualization of retinal vessels in vivo. OCT-A was used to characterize the vascular network of the mouse retina and was compared with fluorescein angiography (FA) and histology. Methods In the present study, OCT-A based on a Heidelberg Engineering Spectralis system was used to investigate the vascular network in mice. Data was compared with FA and confocal microscopy of flat-mount histology stained with isolectin IB4. For quantitative analysis the National Cancer Institute's AngioTool software was used. Vessel density, the number of vessel junctions, and endpoints were measured and compared between the imaging modalities. Results The configuration of the superficial capillary network was comparable with OCT-A and flat-mount histology in BALBc mice. However, vessel density and the number of vessel junctions per region of interest (P = 0.0161 and P = 0.0015, respectively) in the deep vascular network of BALBc mice measured by OCT-A was significantly higher than with flat-mount histology. In C3A.Cg-Pde6b+Prph2Rd2/J mice, where the deep capillary plexus is absent, analysis of the superficial network provided similar results for all three imaging modalities. Conclusion OCT-A is a helpful imaging tool for noninvasive, in vivo imaging of the vascular plexus in mice. It may offer advantages over FA and confocal microscopy especially for imaging the deep vascular plexus. Translational Relevance The present study shows that OCT-A can be employed for small animal imaging to assess the vascular network and offers advantages over flat-mount histology and FA. PMID:27570710

  10. Comparison of the marginal adaptation of direct and indirect composite inlay restorations with optical coherence tomography

    PubMed Central

    TÜRK, Ayşe Gözde; SABUNCU, Metin; ÜNAL, Sena; ÖNAL, Banu; ULUSOY, Mübin

    2016-01-01

    ABSTRACT Objective The purpose of the study was to use the photonic imaging modality of optical coherence tomography (OCT) to compare the marginal adaptation of composite inlays fabricated by direct and indirect techniques. Material and Methods Class II cavities were prepared on 34 extracted human molar teeth. The cavities were randomly divided into two groups according to the inlay fabrication technique. The first group was directly restored on cavities with a composite (Esthet X HD, Dentsply, Germany) after isolating. The second group was indirectly restored with the same composite material. Marginal adaptations were scanned before cementation with an invisible infrared light beam of OCT (Thorlabs), allowing measurement in 200 µm intervals. Restorations were cemented with a self-adhesive cement resin (SmartCem2, Dentsply), and then marginal adaptations were again measured with OCT. Mean values were statistically compared by using independent-samples t-test and paired samples t-test (p<0.05), before and after cementation. Results Direct inlays presented statistically smaller marginal discrepancy values than indirect inlays, before (p=0.00001442) and after (p=0.00001466) cementation. Marginal discrepancy values were increased for all restorations after cementation (p=0.00008839, p=0.000000952 for direct and indirect inlays, respectively). The mean marginal discrepancy value of the direct group increased from 56.88±20.04 µm to 91.88±31.7 µm, whereas the indirect group increased from 107.54±35.63 µm to 170.29±54.83 µm. Different techniques are available to detect marginal adaptation of restorations, but the OCT system can give quantitative information about resin cement thickness and its interaction between tooth and restoration in a nondestructive manner. Conclusions Direct inlays presented smaller marginal discrepancy than indirect inlays. The marginal discrepancy values were increased for all restorations that refer to cement thickness after cementation

  11. Respiratory gating in positron emission tomography: A quantitative comparison of different gating schemes

    SciTech Connect

    Dawood, Mohammad; Buether, Florian; Lang, Norbert; Schober, Otmar; Schaefers, Klaus P

    2007-07-15

    Respiratory gating is used for reducing the effects of breathing motion in a wide range of applications from radiotherapy treatment to diagnostical imaging. Different methods are feasible for respiratory gating. In this study seven gating methods were developed and tested on positron emission tomography (PET) listmode data. The results of seven patient studies were compared quantitatively with respect to motion and noise. (1) Equal and (2) variable time-based gating methods use only the time information of the breathing cycle to define respiratory gates. (3) Equal and (4) variable amplitude-based gating approaches utilize the amplitude of the respiratory signal. (5) Cycle-based amplitude gating is a combination of time and amplitude-based techniques. A baseline correction was applied to methods (3) and (4) resulting in two new approaches: Baseline corrected (6) equal and (7) variable amplitude-based gating. Listmode PET data from seven patients were acquired together with a respiratory signal. Images were reconstructed applying the seven gating methods. Two parameters were used to quantify the results: Motion was measured as the displacement of the heart due to respiration and noise was defined as the standard deviation of pixel intensities in a background region. The amplitude-based approaches (3) and (4) were superior to the time-based methods (1) and (2). The improvement in capturing the motion was more than 30% (up to 130%) in all subjects. The variable time (2) and amplitude (4) methods had a more uniform noise distribution among all respiratory gates compared to equal time (1) and amplitude (3) methods. Baseline correction did not improve the results. Out of seven different respiratory gating approaches, the variable amplitude method (4) captures the respiratory motion best while keeping a constant noise level among all respiratory phases.

  12. Comparison of electrical capacitance tomography & gamma densitometer measurement in viscous oil-gas flows

    NASA Astrophysics Data System (ADS)

    Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

    2014-04-01

    Multiphase flow is a common occurrence in industries such as nuclear, process, oil & gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil & gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 & 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 & 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

  13. Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows

    SciTech Connect

    Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

    2014-04-11

    Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

  14. A comparison of methods for in situ discrimination of imaged phase boundaries using electrical capacitance tomography

    NASA Astrophysics Data System (ADS)

    Clark, P. J.; Tsoligkas, A. N.; Simmons, M. J. H.; Robbins, P. T.; Stitt, E. H.

    2016-02-01

    The detection of hard boundaries using tomographic techniques is challenging due to the measurement resolution inherent in the hardware and smoothing effects created during image reconstruction. This paper is concerned with the development of data processing approaches which enable the use of electrical capacitance tomography (ECT) in real-time applications to visualise interfaces in liquid/liquid and solid/liquid systems based upon phase permittivity differences in media with a high di-electric continuum. The methodologies developed were applied to a series of phantoms to investigate their validity as a tool for imaging phase boundaries in two and three phase systems. In an ECT based tomogram, the interface between phases is exhibited as a transition region; by applying a threshold technique based upon known areas of each respective phase within the system, the transient region can be resolved into a sharp interface. The image error of a tomogram, defined as the deviation of all pixels from their theoretical value, has been calculated using a pixel-by-pixel approach; however this requires exact a priori knowledge and is unsuitable for in-line application; the areal method used in this paper requires global phase distribution information thereby allowing for real-time application. A range of threshold values were applied to tomograms of phantoms of varying geometry and the corresponding image error for each threshold value calculated using both the areal and pixel-by-pixel approaches given above. The threshold value yielding lowest image error from this range is further used in the binary images giving improved tomograms with approximately 40% increase in image accuracy when compared with a default threshold value. Close to the sensor wall, the image becomes distorted due to reconstruction errors arising from decreased density in the electrical field lines, resulting in a circular phantom appearing elongated by approximately 10% when positioned near the wall.

  15. Comparison of cone-beam computed tomography cephalometric measurements using a midsagittal projection and conventional two-dimensional cephalometric measurements

    PubMed Central

    Jung, Pil-Kyo; Lee, Gung-Chol

    2015-01-01

    Objective This study investigated whether it is possible to use a two-dimensional (2D) standard in three-dimensional (3D) analysis, by comparing the angles and lengths measured from a midsagittal projection in 3D cone-beam computed tomography (CBCT) with those measured by 2D lateral cephalometric radiography (LCR). Methods Fifty patients who underwent both LCR and CBCT were selected as subjects. CBCT was reoriented in 3 different methods and the measuring-points were projected onto the midsagittal plane. Twelve angle values and 8 length values were measured on both LCR and CBCT and compared. Results Repeated measures analysis of the variance revealed statistically significant differences in 7 angular and 5 linear measurements among LCR and 3 types of CBCT (p < 0.05). Of these 12 measurements, multiple comparisons showed that 6 measurements (ANB, AB to FH, IMPA, FMA, Co-Gn, Go-Me) were not significantly different in pairwise comparisons. LCR was significantly different from 3 types of CBCT in 3 angular (SN to FH, interincisal angle, FMIA) and 2 linear (S-Go, Co-ANS) measurements. The CBCT method was similar for all measurements, except for 1 linear measurement, i.e., S-N. However, the disparity between the mean values for all parameters was within the range of clinical measurement error. Conclusions 3D-CBCT analysis, using midsagittal projection, is a useful method in which the 2D-LCR normative values can be used. Although the measurements changed with reorientation, these changes were not clinically significant. PMID:26629474

  16. Magnetic resonance imaging and computed tomography in emergency assessment of patients with suspected acute stroke: a prospective comparison

    PubMed Central

    Chalela, Julio A; Kidwell, Chelsea S; Nentwich, Lauren M; Luby, Marie; Butman, John A; Demchuk, Andrew M; Hill, Michael D; Patronas, Nicholas; Latour, Lawrence; Warach, Steven

    2007-01-01

    Summary Background Although the use of magnetic resonance imaging (MRI) for the diagnosis of acute stroke is increasing, this method has not proved more effective than computed tomography (CT) in the emergency setting. We aimed to prospectively compare CT and MRI for emergency diagnosis of acute stroke. Methods We did a single-centre, prospective, blind comparison of non-contrast CT and MRI (with diffusion-weighted and susceptibility weighted images) in a consecutive series of patients referred for emergency assessment of suspected acute stroke. Scans were independently interpreted by four experts, who were unaware of clinical information, MRI-CT pairings, and follow-up imaging. Results 356 patients, 217 of whom had a final clinical diagnosis of acute stroke, were assessed. MRI detected acute stroke (ischaemic or haemorrhagic), acute ischaemic stroke, and chronic haemorrhage more frequently than did CT (p<0.0001, for all comparisons). MRI was similar to CT for the detection of acute intracranial haemorrhage. MRI detected acute ischaemic stroke in 164 of 356 patients (46%; 95% CI 41-51%), compared with CT in 35 of 356 patients (10%; 7-14%). In the subset of patients scanned within 3 h of symptom onset, MRI detected acute ischaemic stroke in 41 of 90 patients (46%; 35-56%); CT in 6 of 90 (7%; 3-14%). Relative to the final clinical diagnosis, MRI had a sensitivity of 83% (181 of 217; 78-88%) and CT of 26% (56 of 217; 20-32%) for the diagnosis of any acute stroke. Interpretation MRI is better than CT for detection of acute ischaemia, and can detect acute and chronic haemorrhage; therefore it should be the preferred test for accurate diagnosis of patients with suspected acute stroke. Because our patient sample encompassed the range of disease that is likely to be encountered in emergency cases of suspected stroke, our results are directly applicable to clinical practice. PMID:17258669

  17. COMPARISON OF QUANTITATIVE COMPUTED TOMOGRAPHY-BASED MEASURES IN PREDICTING VERTEBRAL COMPRESSIVE STRENGTH

    PubMed Central

    Buckley, Jenni M.; Loo, Kenneth; Motherway, Julie

    2007-01-01

    Patient-specific measures derived from quantitative computed tomography (QCT) scans are currently being developed as a clinical tool for vertebral strength prediction. QCT-based measurement techniques vary greatly in structural complexity and generally fall into one of three categories: 1) bone mineral density (BMD), 2) “mechanics of solids” (MOS) models, such as minimum axial rigidity (the product of axial stiffness and vertebral height), or 3) three dimensional finite element (FE) models. There is no clear consensus as to the relative performance of these measures due to differences in experimental protocols, sample sizes and demographics, and outcome metrics. The goal of this study was to directly compare the performance of QCT-based assessment techniques of varying degrees of structural sophistication in predicting experimental vertebral compressive strength. Eighty-one human thoracic vertebrae (T6 – T10) from 44 donors cadavers (F = 32, M = 12; 85 + 8 y.o., max = 97 y.o., min = 54 y.o.) were QCT scanned and destructively tested in uniaxial compression. The QCT scans were processed to generate FE models and various BMD and MOS measures, including trabecular bone mineral density (tBMD), integral bone mineral density (iBMD), and axial rigidity. Bone mineral density was weakly to moderately predictive of compressive strength (R2 = 0.16 and 0.62 for tBMD and iBMD, respectively). Ex vivo vertebral strength was strongly correlated with both axial rigidity (R2 = 0.81) and FE strength measurements (R2 = 0.80), and the predictive capabilities of these two metrics were statistically equivalent (p > 0.05 for differences between FE and axial rigidity). The results of this study indicate that non-invasive predictive measures of vertebral strength should include some level of structural sophistication, specifically, gross geometric and material property distribution information. However, for uniaxial compression of isolated vertebrae, which is the current biomechanical

  18. Retinal Nerve Fiber Layer Thickness Measurement Comparison Using Spectral Domain and Swept Source Optical Coherence Tomography

    PubMed Central

    Ha, Ahnul; Lee, Seung Hyen; Lee, Eun Ji

    2016-01-01

    Purpose To investigate the retinal nerve fiber layer (RNFL) thickness concordance when measured by spectral domain (SD) and swept source (SS) optical coherence tomography (OCT), and to compare glaucoma-discriminating capability. Methods RNFL thicknesses were measured with the scan circle, centered on the optic nerve head, in 55 healthy, 41 glaucoma suspected, and 87 glaucomatous eyes. The RNFL thickness measured by the SD-OCT (sdRNFL thickness) and SS-OCT (ssRNFL thickness) were compared using the t-test. Bland-Altman analysis was performed to examine their agreement. We compared areas under the receiver operating characteristics curve and examined sdRNFL and ssRNFL thickness for discriminating glaucomatous eyes from healthy eyes, and from glaucoma suspect eyes. Results The average ssRNFL thickness was significantly greater than sdRNFL thickness in healthy (110.0 ± 7.9 vs. 100.1 ± 6.8 µm, p < 0.001), glaucoma suspect (96.8 ± 9.3 vs. 89.6 ± 7.9 µm, p < 0.001), and glaucomatous eyes (74.3 ± 14.2 vs. 69.1 ± 12.4 µm, p = 0.011). Bland-Altman analysis showed that there was a tendency for the difference between ssRNFL and sdRNFL to increase in eyes with thicker RNFL. The area under the curves of the average sdRNFL and ssRNFL thickness for discriminating glaucomatous eyes from healthy eyes (0.984 vs. 0.986, p = 0.491) and glaucoma suspect eyes (0.936 vs. 0.918, p = 0.132) were comparable. Conclusions There was a tendency for ssRNFL thickness to increase, compared with sdRNFL thickness, in eyes with thicker RNFL. The ssRNFL thickness had comparable diagnostic capability compared with sdRNFL thickness for discriminating glaucomatous eyes from healthy eyes and glaucoma suspect eyes. PMID:27051263

  19. Comparison of sound speed measurements on two different ultrasound tomography devices

    NASA Astrophysics Data System (ADS)

    Sak, Mark; Duric, Neb; Littrup, Peter; Bey-Knight, Lisa; Sherman, Mark; Gierach, Gretchen; Malyarenko, Antonina

    2014-03-01

    Ultrasound tomography (UST) employs sound waves to produce three-dimensional images of breast tissue and precisely measures the attenuation of sound speed secondary to breast tissue composition. High breast density is a strong breast cancer risk factor and sound speed is directly proportional to breast density. UST provides a quantitative measure of breast density based on three-dimensional imaging without compression, thereby overcoming the shortcomings of many other imaging modalities. The quantitative nature of the UST breast density measures are tied to an external standard, so sound speed measurement in breast tissue should be independent of specific hardware. The work presented here compares breast sound speed measurement obtained with two different UST devices. The Computerized Ultrasound Risk Evaluation (CURE) system located at the Karmanos Cancer Institute in Detroit, Michigan was recently replaced with the SoftVue ultrasound tomographic device. Ongoing clinical trials have used images generated from both sets of hardware, so maintaining consistency in sound speed measurements is important. During an overlap period when both systems were in the same exam room, a total of 12 patients had one or both of their breasts imaged on both systems on the same day. There were 22 sound speed scans analyzed from each system and the average breast sound speeds were compared. Images were either reconstructed using saved raw data (for both CURE and SoftVue) or were created during the image acquisition (saved in DICOM format for SoftVue scans only). The sound speed measurements from each system were strongly and positively correlated with each other. The average difference in sound speed between the two sets of data was on the order of 1-2 m/s and this result was not statistically significant. The only sets of images that showed a statistical difference were the DICOM images created during the SoftVue scan compared to the SoftVue images reconstructed from the raw data

  20. Comparison among GPR measurements and ultrasonic tomographies with different inversion strategies applied to the basement of an ancient egyptian sculpture.

    NASA Astrophysics Data System (ADS)

    Sambuelli, Luigi; Bohm, Gualtiero; Capizzi, Patrizia; Cardarelli, Ettore; Cosentino, Pietro; D'Onofrio, Laurent; Marchisio, Mario

    2010-05-01

    By the late 2008 one of the most important pieces of the "Museo delle Antichità Egizie" in Turin, the sculpture of the Pharaoh with god Amun, was planned to be one of the masterpieces of a travelling exhibition in Japan. The "Fondazione Museo delle Antichità Egizie di Torino", managing the museum, was concerned with the integrity of the basement of the statue which actually presents visible signs of restorations dating back to the early IXX century. The questions put by the museum managers were to estimate the internal extension of some visible fractures, to search for unknown internal ones and to provide information about the overall mechanical strength of the basement. In order to tackle the first and second questions a GPR reflection survey of the basement along three sides was performed and the results were assembled in a 3D rendering. As far as the third question is concerned, two parallel, horizontal ultrasonic 2D tomographies across the basement were made with a source-receiver layout able to acquire, for each section, 723 ultrasonic signals correspondent to different transmitter and receiver positions. The ultrasonic tomographic data were inverted using different software based upon different algorithms. The obtained velocity images were then compared with the GPR results and with the visible joints on the basement. A critical analysis of the comparisons is finally presented.

  1. Comparison of cardiac output of the left and right side of the heart by ultrafast computed tomography

    SciTech Connect

    Wolfkiel, C.J.; Ferguson, J.L.; Law, W.R.; Chomka, E.V.; Brundage, B.H.

    1986-03-05

    Ultrafast computed tomography (CT) evaluation of cardiac output (CO) can be determined using indicator dilution theory. The concentration of an iodinated contrast agent injected into a vein of a subject can be measured as a function of time by serial EKG, gated CT imaging. The contrast density of the blood pool measured by CT defines the indicator concentration. CT CO is proportional to the area under a time density curve from a region of the blood pool. Proper subject position and scanning timing allows CT to measure CO in the pulmonary (PA) artery and the aorta (AO) with the same contrast bolus. Three anesthetized dogs were multiply scanned following simultaneous injections of contrast and radioactive tracer microspheres. Microsphere CO was determined by reference withdrawal method. Multiple thermodilution CO measurements were made just prior and after each CT CO procedure. 24 comparisons were made of thermodilution, microsphere and CT CO measured in the PA (right sided CO (RSCO)) and the AO (left sided CO (LSCO)). CT CO was calculated as the ratio of the volume of contrast injected to the time density curve area corrected for the relation of contrast density to CT number. RSCO agreed very closely to LSCO (r = .99, p < .001; y = 1.0x +/- .32). RSCO correlated to thermodilution (r = .96, p < .001; y = 1.2x +/- 1.3) and microsphere CO (r = .93, p < .001; y = .69x +/- 1.3). These data show that CT CO measurements can be made in the PA and AO with equal accuracy.

  2. Comparison of analyzer-based imaging computed tomography extraction algorithms and application to bone-cartilage imaging.

    PubMed

    Diemoz, Paul C; Bravin, Alberto; Glaser, Christian; Coan, Paola

    2010-12-21

    In x-ray phase-contrast analyzer-based imaging, the contrast is provided by a combination of absorption, refraction and scattering effects. Several extraction algorithms, which attempt to separate and quantify these different physical contributions, have been proposed and applied. In a previous work, we presented a quantitative comparison of five among the most well-known extraction algorithms based on the geometrical optics approximation applied to planar images: diffraction-enhanced imaging (DEI), extended diffraction-enhanced imaging (E-DEI), generalized diffraction-enhanced imaging (G-DEI), multiple-image radiography (MIR) and Gaussian curve fitting (GCF). In this paper, we compare these algorithms in the case of the computed tomography (CT) modality. The extraction algorithms are applied to analyzer-based CT images of both plastic phantoms and biological samples (cartilage-on-bone cylinders). Absorption, refraction and scattering signals are derived. Results obtained with the different algorithms may vary greatly, especially in the case of large refraction angles. We show that ABI-CT extraction algorithms can provide an excellent tool to enhance the visualization of cartilage internal structures, which may find applications in a clinical context. Besides, by using the refraction images, the refractive index decrements for both the cartilage matrix and the cartilage cells have been estimated. PMID:21113091

  3. Comparison of Computed Tomography and Cineangiography in the Demonstration of Central Pulmonary Arteries in Cyanotic Congenital Heart Disease

    SciTech Connect

    Taneja, Karuna; Sharma, Sanjiv; Kumar, Krishan; Rajani, Mira

    1996-03-15

    Purpose: To assess the diagnostic accuracy of contrast-enhanced computed tomography (CT) for central pulmonary artery pathology in patients with cyanotic congenital heart disease (CCHD) and right ventricular outflow obstruction. Methods: We compared contrast-enhanced CT and cine pulmonary arteriography in 24 patients with CCHD to assess central pulmonary arteries including the confluence. Both investigations were interpreted by a cardiac radiologist in a double-blinded manner at an interval of 3 weeks. Angiography was used as the gold standard for comparison. Results: The sensitivity for visualization of main pulmonary artery (MPA), right pulmonary artery (RPA), left pulmonary artery (LPA), and confluence on CT was 94%, 100%, 92.8%, and 92.8%, respectively. Diagnostic specificity for the same entities was 28.5%, 100%, 80%, and 50%, respectively. The positive predictive value for each was 76.2%, 100%, 94.1%, and 72.2%, respectively. The low specificity of CT in the evaluation of the MPA and the confluence is perhaps due to distorted right ventricular outflow anatomy in CCHD. Large aortopulmonary collaterals in this region were mistaken for the MPA in some patients with pulmonary atresia. Conclusion: CT is a useful, relatively noninvasive, imaging technique for the central pulmonary arteries in selected patients. It can supplement diagnostic information from angiography but cannot replace it. LPA demonstration on axial images alone is inadequate.

  4. Electrical resistivity tomography applied to a complex lava dome: 2D and 3D models comparison

    NASA Astrophysics Data System (ADS)

    Portal, Angélie; Fargier, Yannick; Lénat, Jean-François; Labazuy, Philippe

    2015-04-01

    The study of volcanic domes growth (e.g. St. Helens, Unzen, Montserrat) shows that it is often characterized by a succession of extrusion phases, dome explosions and collapse events. Lava dome eruptive activity may last from days to decades. Therefore, their internal structure, at the end of the eruption, is complex and includes massive extrusions and lava lobes, talus and pyroclastic deposits as well as hydrothermal alteration. The electrical resistivity tomography (ERT) method, initially developed for environmental and engineering exploration, is now commonly used for volcano structure imaging. Because a large range of resistivity values is often observed in volcanic environments, the method is well suited to study the internal structure of volcanic edifices. We performed an ERT survey on an 11ka years old trachytic lava dome, the Puy de Dôme volcano (French Massif Central). The analysis of a recent high resolution DEM (LiDAR 0.5 m), as well as other geophysical data, strongly suggest that the Puy de Dôme is a composite dome. 11 ERT profiles have been carried out, both at the scale of the entire dome (base diameter of ~2 km and height of 400 m) on the one hand, and at a smaller scale on the summit part on the other hand. Each profile is composed of 64 electrodes. Three different electrode spacing have been used depending on the study area (35 m for the entire dome, 10 m and 5 m for its summit part). Some profiles were performed with half-length roll-along acquisitions, in order to keep a good trade-off between depth of investigation and resolution. Both Wenner-alpha and Wenner-Schlumberger protocols were used. 2-D models of the electrical resistivity distribution were computed using RES2DINV software. In order to constrain inversion models interpretation, the depth of investigation (DOI) method was applied to those results. It aims to compute a sensitivity index on inversion results, illustrating how the data influence the model and constraining models

  5. Comparison between computed tomography multislice and high-field magnetic resonance in the diagnostic evaluation of patients with renal masses

    PubMed Central

    Baldari, Diana; Capece, Sergio; Mainenti, Pier Paolo; Tucci, Anna Giacoma; Klain, Michele; Cozzolino, Immacolata; Salvatore, Marco

    2015-01-01

    Background Renal masses are a common finding in diagnostic imaging; these lesions usually are solid or cystic, benign or malignant, and the correct diagnosis may be difficult. The aim of our study was the comparison of multi-slice computed tomography (MSCT) and high-field magnetic resonance (MR) in the diagnostic evaluation of renal masses. Methods We studied 29 patients, 16 men and 13 women aged 8-85 years (mean 61±17 years) with histo-cytological diagnosis of renal masses (n=31), of which the majority (74%; n=23) was represented by malignant lesions [renal cell carcinoma (Ca) =16, chromophobe renal cell Ca =2, squamous cell Ca =1, urothelial Ca =2, lymphoma =1, Wilms tumor =1]; the remaining 8 masses (26%) were benign (pyelonephritis =2, simple cyst =1, hematic cyst =1, lipoma =1 and oncocytoma =3). All patients underwent MSCT and MR (3.0 Tesla) before and after contrast injection; the images were evaluated in double-blind by two expert radiologists. The results of the images were then compared with the histo-cytological data to calculate the values of diagnostic accuracy for both methods in the identification and characterization of renal masses. The benign or malignant nature of the lesions was established according to the regularity of the margins, presence or absence of significant contrast enhancement, infiltration of perirenal fat and vascular invasion. The concordance of the results of the two imaging techniques was then calculated using the coefficient Kappa Cohen. Results For both identification and characterization of renal masses, MSCT and MR showed comparable values of diagnostic accuracy with a significant concordance (k=1); in particular, the diagnostic accuracy of MSCT/MR was 100%/100% for lesion identification, 90%/90% for lesion characterization in terms of benign or malignant nature, 97%/97% for the evaluation of lesion edges, 90%/90% for the assessment of lesion contrast enhancement, 93%/93% for the evaluation of peri-renal fat infiltration

  6. Evolution of microcomputer-based medical instrumentation.

    PubMed

    Tompkins, Willis J

    2009-01-01

    This paper provides a historical review of the evolution of the technologies that led to modern microcomputer-based medical instrumentation. I review the history of the microprocessor-based system because of the importance of the microprocessor in the design of modern medical instruments. I then give some examples of medical instruments in which the microprocessor has played a key role and in some cases has even empowered us to develop new instruments that were not possible before. I include a discussion of the role of the microprocessor-based personal computer in development of medical instruments.

  7. Comparison of Diagnostic Accuracy of Radiation Dose-Equivalent Radiography, Multidetector Computed Tomography and Cone Beam Computed Tomography for Fractures of Adult Cadaveric Wrists

    PubMed Central

    Neubauer, Jakob; Benndorf, Matthias; Reidelbach, Carolin; Krauß, Tobias; Lampert, Florian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Fiebich, Martin; Goerke, Sebastian M.

    2016-01-01

    Purpose To compare the diagnostic accuracy of radiography, to radiography equivalent dose multidetector computed tomography (RED-MDCT) and to radiography equivalent dose cone beam computed tomography (RED-CBCT) for wrist fractures. Methods As study subjects we obtained 10 cadaveric human hands from body donors. Distal radius, distal ulna and carpal bones (n = 100) were artificially fractured in random order in a controlled experimental setting. We performed radiation dose equivalent radiography (settings as in standard clinical care), RED-MDCT in a 320 row MDCT with single shot mode and RED-CBCT in a device dedicated to musculoskeletal imaging. Three raters independently evaluated the resulting images for fractures and the level of confidence for each finding. Gold standard was evaluated by consensus reading of a high-dose MDCT. Results Pooled sensitivity was higher in RED-MDCT with 0.89 and RED-MDCT with 0.81 compared to radiography with 0.54 (P = < .004). No significant differences were detected concerning the modalities’ specificities (with values between P = .98). Raters' confidence was higher in RED-MDCT and RED-CBCT compared to radiography (P < .001). Conclusion The diagnostic accuracy of RED-MDCT and RED-CBCT for wrist fractures proved to be similar and in some parts even higher compared to radiography. Readers are more confident in their reporting with the cross sectional modalities. Dose equivalent cross sectional computed tomography of the wrist could replace plain radiography for fracture diagnosis in the long run. PMID:27788215

  8. Microcomputers: Communication Software. Evaluation Guides. Guide Number 13.

    ERIC Educational Resources Information Center

    Gray, Peter J.

    This guide discusses four types of microcomputer-based communication programs that could prove useful to evaluators: (1) the direct communication of information generated by one computer to another computer; (2) using the microcomputer as a terminal to a mainframe computer to input, direct the analysis of, and/or output data using a statistical…

  9. Evaluator's Guide for Microcomputer-Based Instructional Packages.

    ERIC Educational Resources Information Center

    Northwest Regional Educational Lab., Portland, OR.

    This guide developed by MicroSIFT, a clearinghouse for microcomputer-based educational software and courseware, provides background information and forms to aid teachers and other educators in evaluating available microcomputer courseware. The evaluation process comprises four stages: (1) sifting, which screens out those programs that are not…

  10. Microcomputer Telecommunication: Bringing Education Online for an Expanded Classroom.

    ERIC Educational Resources Information Center

    Schooler, Douglas K.

    This document is designed as a comprehensive resource and guide for computer-using educators who wish to expand the scope and magnitude of their computer power through telecommunications. The major focus is on the microcomputer's ability to communicate with other microcomputers via telephone lines. Emphasis is placed upon information services and…

  11. Handbook and Annotated Software Bibliography. Microcomputers in ABE.

    ERIC Educational Resources Information Center

    Holter, Mary Patricia; Johnson, Carmen

    This handbook and annotated bibliography presents discussions, ideas, and resources useful to adult basic education (ABE) program teachers and administrators in implementing educational microcomputing, and describes microcomputer software programs that have been used successfully in ABE. The first part of the book, the handbook, is organized in…

  12. Microcomputers: Introduction to Features and Uses. Final Report.

    ERIC Educational Resources Information Center

    Hecht, Myron; And Others

    This introduction to microcomputers and their implementation and use in federal agencies discusses both basic concepts in microcomputers and their specific uses by clerical, administrative, professional, and technical federal personnel. Issues concerned with the use of specialized application software and integrated packages--word processing, data…

  13. Microcomputers in Education: A Self-Paced Orientation.

    ERIC Educational Resources Information Center

    Carey, Doris; Carey, Regan

    Designed to serve as a self-paced computer course for education students with no experience using microcomputers, this manual contains instructions for operating an Apple IIe microcomputer, its introductory software, and Bank Street Writer, using the DOS 3.3 System Master. The lessons, which contain illustrations and sample screens, include…

  14. Interfacing Commodore Microcomputers with a Laboratory Device: A Thermometer Probe.

    ERIC Educational Resources Information Center

    Powers, Michael H.

    1986-01-01

    Describes hardware and software requirements for interfacing a thermometer probe, via an analog and digital converter, to any Commodore PET, VIC-20, or Commodore-64 microcomputer (or other microcomputers with some modifications). Also describes use of the probe in an experiment measuring enthalpies of reaction to determine enthalpy of formation of…

  15. The Effects of Microcomputers on Children's Attention to Reading Tasks.

    ERIC Educational Resources Information Center

    Zuk, Dorie; Danner, Fred

    A study investigated the effects of microcomputers on children's attention to reading tasks and the relationship between previous reading achievement and grade level on such attentional behavior. Fifty-five third and fifth graders read two stories each, one presented on a microcomputer and one presented in print. Television cartoons and rock music…

  16. The Microcomputer in the Library: II. Hardware and Operating Systems.

    ERIC Educational Resources Information Center

    Leggate, Peter; Dyer, Hilary

    1985-01-01

    This second in a series of six articles introducing microcomputer applications in smaller libraries describes the main microcomputer hardware components--processors, internal and external memory, buses, printers, communications, hardware. Importance of ergonomic factors in equipment design, multi-user and network configurations, and the role of…

  17. A Guide to Microcomputer Programs in the California Community Colleges.

    ERIC Educational Resources Information Center

    Dimsdale, Jeffrey M., Ed.

    Designed to assist faculty in California community colleges in sharing microcomputer programs they have written, this guide provides abstracts for 89 teacher-developed microcomputer programs that can be obtained for non-commercial use. Each entry contains information on the title and author of the program, the institution of the author, the…

  18. Creating Microcomputer Graphics with the KoalaPad.

    ERIC Educational Resources Information Center

    White, Dennis W.

    1985-01-01

    The KoalaPad, an advanced graphic tablet introduced in 1983, reduces the cost and the degree of programing background required to create sophisticated images on the microcomputer. The potentials of the KoalaPad for use in an art education program are discussed, and recommendations for creating a microcomputer graphics lab are presented. (RM)

  19. Microcomputing in North Carolina Libraries: A Special Section.

    ERIC Educational Resources Information Center

    Speller, Benjamin F., Jr., Ed.; Burgin, Robert, Ed.

    1982-01-01

    The eight articles in this special section on microcomputer applications in libraries discuss selection of microcomputer courseware for school media collections, public and special libraries, information retrieval, and library education. References and an annotated bibliography are provided. (Request subscription information from W. Robert…

  20. A microcomputer program for analysis of nucleic acid hybridization data

    PubMed Central

    Green, S.; Field, J.K.; Green, C.D.; Beynon, R.J.

    1982-01-01

    The study of nucleic acid hybridization is facilitated by computer mediated fitting of theoretical models to experimental data. This paper describes a non-linear curve fitting program, using the `Patternsearch' algorithm, written in BASIC for the Apple II microcomputer. The advantages and disadvantages of using a microcomputer for local data processing are discussed. Images PMID:7071017

  1. TLC for Growing Minds. Microcomputer Projects. Advanced Projects for Adults.

    ERIC Educational Resources Information Center

    Taitt, Henry A.

    Designed to improve students' thinking, learning, and creative skills while they learn to program a microcomputer in BASIC programing language, this book for advanced learners at the high school/adult level provides a variety of microcomputer activities designed to extend the concepts learned in the accompanying instructional manuals (volumes 3…

  2. Enhancing a Mainframe Library System through Microcomputer Technology.

    ERIC Educational Resources Information Center

    Breeding, Marshall

    1988-01-01

    Discusses ways a microcomputer system might enhance the mainframe library system at Vanderbilt University. Topics include: (1) types of microcomputers; (2) types of terminals; (3) characteristics of a dumb terminal; (4) characteristics of an intelligent terminal; (5) which terminals should be given additional features; and (6) designing an…

  3. Microcomputer Selection Guidelines for Administrators. Operations Notebook No. 30.

    ERIC Educational Resources Information Center

    Coombs, Robert W.; And Others

    Designed to assist administrators in making intelligent decisions about microcomputer selection, this nontechnical guide provides information in three areas: how, where, when, and why to use a microcomputer; what questions to ask about software and hardware; and what terminology to use. It provides a framework for answering six questions the…

  4. Microcomputer Technology: Its impact on Teachers in an Elementary School.

    ERIC Educational Resources Information Center

    Hope, Warren C.

    The purpose of this study was to examine the initiation and implementation of microcomputer technology in the educational environment of N.H. Jones Elementary School (Ocala, Florida) and to assess its impact on teachers. Microcomputer technology was configured as a teacher workstation. A conceptual framework was developed to promote microcomputer…

  5. Applications of Local Area Networks of Microcomputers in Libraries.

    ERIC Educational Resources Information Center

    Levert, Virginia M.

    1985-01-01

    Important features of local area networks (LAN) are reviewed, and several microcomputer LANs are described (ARCnet, Hinet, ShareNet, Ethernet, Omninet, PLAN 4000). Results of survey of 10 libraries using or planning to use a microcomputer LAN and considerations in choosing a LAN are reported. Forty-one references are cited. (EJS)

  6. User's manual for levelized power generation cost using a microcomputer

    SciTech Connect

    Fuller, L.C.

    1984-08-01

    Microcomputer programs for the estimation of levelized electrical power generation costs are described. Procedures for light-water reactor plants and coal-fired plants include capital investment cost, operation and maintenance cost, fuel cycle cost, nuclear decommissioning cost, and levelized total generation cost. Programs are written in Pascal and are run on an Apple II Plus microcomputer.

  7. Information survey for microcomputer systems integration

    SciTech Connect

    Hake, K.A.

    1991-12-01

    One goal of the PM-AIM is to provide US Army Project Managers (PMs) and Project Executive Officers (PEOs) with a fundamental microcomputing resource to help perform acquisition information management and its concomitant reporting requirements. Providing key application software represents one means of accomplishing this goal. This workstation would furnish a broad range of capabilities needed in the PM and PEO office settings as well as software tools for specific project management and acquisition information. Although still in the conceptual phase, the practical result of this exercise in systems integration will likely be a system called the Project Manager's Information System (PMIS) or the AIM workstation. It would include such software as, Project Manager's System Software (PMSS), Defense Acquisition Executive Summary (DAES), and Consolidated Acquisition Reporting System (CARS) and would conform to open systems architecture as accepted by the Department of Defense. ORNL has assisted PM-AIM in the development of technology ideas for the PMIS workstation concept. This paper represents the compilation of information gained during this process. This information is presented as a body of knowledge (or knowledge domain) defining the complex technology of microcomputing. The concept of systems integration or tying together all hardware and software components reflects the nature of PM-AIM's task in attempting to field a PMIS or AIM workstation.

  8. Information survey for microcomputer systems integration

    SciTech Connect

    Hake, K.A.

    1991-12-01

    One goal of the PM-AIM is to provide US Army Project Managers (PMs) and Project Executive Officers (PEOs) with a fundamental microcomputing resource to help perform acquisition information management and its concomitant reporting requirements. Providing key application software represents one means of accomplishing this goal. This workstation would furnish a broad range of capabilities needed in the PM and PEO office settings as well as software tools for specific project management and acquisition information. Although still in the conceptual phase, the practical result of this exercise in systems integration will likely be a system called the Project Manager`s Information System (PMIS) or the AIM workstation. It would include such software as, Project Manager`s System Software (PMSS), Defense Acquisition Executive Summary (DAES), and Consolidated Acquisition Reporting System (CARS) and would conform to open systems architecture as accepted by the Department of Defense. ORNL has assisted PM-AIM in the development of technology ideas for the PMIS workstation concept. This paper represents the compilation of information gained during this process. This information is presented as a body of knowledge (or knowledge domain) defining the complex technology of microcomputing. The concept of systems integration or tying together all hardware and software components reflects the nature of PM-AIM`s task in attempting to field a PMIS or AIM workstation.

  9. A microcomputer-based emergency response system*.

    PubMed

    Belardo, S; Howell, A; Ryan, R; Wallace, W A

    1983-09-01

    A microcomputer-based system was developed to provide local officials responsible for disaster management with assistance during the crucial period immediately following a disaster, a period when incorrect decisions could have an adverse impact on the surrounding community. While the paper focuses on a potential disaster resulting from an accident at a commercial nuclear power generating facility, the system can be applied to other disastrous situations. Decisions involving evacuation, shelter and the deployment of resources must be made in response to floods, earthquakes, accidents in the transportation of hazardous materials, and hurricanes to name a few examples. As a decision aid, the system was designed to enhance data display by presenting the data in the form of representations (i.e. road maps, evacuation routes, etc.) as well as in list or tabular form. The potential impact of the event (i.e. the release of radioactive material) was displayed in the form of a cloud, representing the dispersion of the radioactive material. In addition, an algorithm was developed to assist the manager in assigning response resources to demands. The capability for modelling the impact of a disaster is discussed briefly, with reference to a system installed in the communities surrounding the Indian Point nuclear power plant in New York State. Results demonstrate both the technical feasibility of incorporating microcomputers indecision support systems for radiological emergency response, and the acceptance of such systems by those public officials responsible for implementing the response plans.

  10. Automated segmentation of porcine airway wall layers using optical coherence tomography: comparison with manual segmentation and histology

    NASA Astrophysics Data System (ADS)

    Kirby, Miranda; Lee, Anthony M. D.; Candido, Tara; MacAulay, Calum; Lane, Pierre; Lam, Stephen; Coxson, Harvey O.

    2014-03-01

    The objective was to develop an automated optical coherence tomography (OCT) segmentation method. We evaluated three ex-vivo porcine airway specimens; six non-sequential OCT images were selected from each airway specimen. Histology was also performed for each airway and histology images were co-registered to OCT images for comparison. Manual segmentation of the airway luminal area, mucosa area, submucosa area and the outer airway wall area were performed for histology and OCT images. Automated segmentation of OCT images employed a despecking filter for pre-processing, a hessian-based filter for lumen and outer airway wall area segmentation, and K-means clustering for mucosa and submucosa area segmentation. Bland-Altman analysis indicated that there was very little bias between automated OCT segmentation and histology measurements for the airway lumen area (bias=-6%, 95% CI=-21%-8%), mucosa area, (bias=-4%, 95% CI=-14%-5%), submucosa area (bias=7%, 95% CI=-7%-20%) and outer airway wall area segmentation results (bias=-5%, 95% CI=-14%-5%). We also compared automated and manual OCT segmentation and Bland-Altman analysis indicated that there was negligible bias between luminal area (bias=4%, 95% CI=1%-8%), mucosa area (bias=-3%, 95% CI=-6%-1%), submucosa area (bias=-2%, 95% CI=-10%-6%) and the outer airway wall (bias=-3%, 95% CI=-13%-6%). The automated segmentation method for OCT airway imaging developed here allows for accurate and precise segmentation of the airway wall components, suggesting that translation of this method to in vivo human airway analysis would allow for longitudinal and serial studies.

  11. Multiparameter adjoint tomography of the crust and upper mantle beneath East Asia: 1. Model construction and comparisons

    NASA Astrophysics Data System (ADS)

    Chen, Min; Niu, Fenglin; Liu, Qinya; Tromp, Jeroen; Zheng, Xiufen

    2015-03-01

    We present a 3-D radially anisotropic model of the crust and mantle beneath East Asia down to 900 km depth. Adjoint tomography based on a spectral element method is applied to a phenomenal data set comprising 1.7 million frequency-dependent traveltime measurements from waveforms of 227 earthquakes recorded by 1869 stations. Compressional wave speeds are independently constrained and simultaneously inverted along with shear wave speeds (VSH and VSV) using the same waveform data set with comparable resolution. After 20 iterations, the new model (named EARA2014) exhibits sharp and detailed wave speed anomalies with improved correlations with surface tectonic units compared to previous models. In the upper 100 km, high wave speed (high-V) anomalies correlate very well with the Junggar and Tarim Basins, the Ordos Block, and the Yangtze Platform, while strong low wave speed (low-V) anomalies coincide with the Qiangtang Block, the Songpan Ganzi Fold Belt, the Chuandian Block, the Altay-Sayan Mountain Range, and the back-arc basins along the Pacific and Philippine Sea Plate margins. At greater depths, narrow high-V anomalies correspond to major subduction zones and broad high-V anomalies to cratonic roots in the upper mantle and fragmented slabs in the mantle transition zone. In particular, EARA2014 reveals a strong high-V structure beneath Tibet, appearing below 100 km depth and extending to the bottom of the mantle transition zone, and laterally spanning across the Lhasa and Qiangtang Blocks. In this paper we emphasize technical aspects of the model construction and provide a general discussion through comparisons.

  12. Comparisons of Derived Metrics from Computed Tomography (CT) Scanned Images of Fluvial Sediment from Gravel-Bed Flume Experiments

    NASA Astrophysics Data System (ADS)

    Voepel, Hal; Ahmed, Sharif; Hodge, Rebecca; Leyland, Julian; Sear, David

    2016-04-01

    Uncertainty in bedload estimates for gravel bed rivers is largely driven by our inability to characterize arrangement, orientation and resultant forces of fluvial sediment in river beds. Water working of grains leads to structural differences between areas of the bed through particle sorting, packing, imbrication, mortaring and degree of bed armoring. In this study, non-destructive, micro-focus X-ray computed tomography (CT) imaging in 3D is used to visualize, quantify and assess the internal geometry of sections of a flume bed that have been extracted keeping their fabric intact. Flume experiments were conducted at 1:1 scaling of our prototype river. From the volume, center of mass, points of contact, and protrusion of individual grains derived from 3D scan data we estimate 3D static force properties at the grain-scale such as pivoting angles, buoyancy and gravity forces, and local grain exposure. Here metrics are derived for images from two flume experiments: one with a bed of coarse grains (>4mm) and the other where sand and clay were incorporated into the coarse flume bed. In addition to deriving force networks, comparison of metrics such as critical shear stress, pivot angles, grain distributions, principle axis orientation, and pore space over depth are made. This is the first time bed stability has been studied in 3D using CT scanned images of sediment from the bed surface to depths well into the subsurface. The derived metrics, inter-granular relationships and characterization of bed structures will lead to improved bedload estimates with reduced uncertainty, as well as improved understanding of relationships between sediment structure, grain size distribution and channel topography.

  13. COMPARISONS AMONG RADIOGRAPHY, ULTRASONOGRAPHY AND COMPUTED TOMOGRAPHY FOR EX VIVO CHARACTERIZATION OF STIFLE OSTEOARTHRITIS IN THE HORSE.

    PubMed

    De Lasalle, Julie; Alexander, Kate; Olive, Julien; Laverty, Sheila

    2016-09-01

    A better understanding of imaging characteristics of equine stifle osteoarthritis (OA) may allow earlier detection and improve prognosis. Objectives of this ex vivo, prospective, methods comparison study were to (1) describe the location and severity of naturally acquired OA lesions in the equine stifle using ultrasound (US), radiography (XR), computed tomography (CT), and macroscopic evaluation (ME); (2) compare the diagnostic performance of each imaging modality with ME; and (3) describe subchondral bone mineral density (BMD) in equine stifle joints with OA using CT. Radiographic, CT, and US evaluations were performed on 23 equine cadaver stifles and compared with ME. Significant associations were found between osteophyte global scores for all imaging modalities (CT, P ˂ 0.0001; XR, P = 0.005; US, P = 0.04) vs. ME osteophyte global scores. Osteophytes were detected most frequently in the medial femorotibial (MFT) joint. A specific pattern of osteophytes was observed, with a long ridge of new bone at the insertion of the MFT joint capsule cranially on the medial femoral condyle. A novel caudo-10°proximo-5°lateral-cranio-disto-medial oblique radiographic projection was helpful for detection of intercondylar osteophytes. Multiplanar CT reformatted images were helpful for characterizing all osteophytes. Osteophyte grades at most sites did not differ among modalities. Low sensitivity/specificity for subchondral bone sclerosis and flattening of femoral condyles suggested that these signs may not be reliable radiographic and CT indicators of equine stifle OA. Equine stifle OA was associated with a decrease in BMD and specific sites of focal subchondral bone resorption/cyst formation were found in some specimens. PMID:27237699

  14. Performance comparison between 8- and 14-bit-depth imaging in polarization-sensitive swept-source optical coherence tomography.

    PubMed

    Lu, Zenghai; Kasaragod, Deepa K; Matcher, Stephen J

    2011-03-04

    Recently the effects of reduced bit-depth acquisition on swept-source optical coherence tomography (SS-OCT) image quality have been evaluated by using simulations and empirical studies, showing that image acquisition at 8-bit depth allows high system sensitivity with only a minimal drop in the signal-to-noise ratio compared to higher bit-depth systems. However, in these studies the 8-bit data is actually 12- or 14-bit ADC data numerically truncated to 8 bits. In practice, a native 8-bit ADC could actually possess a true bit resolution lower than this due to the electronic jitter in the converter etc. We compare true 8- and 14-bit-depth imaging of SS-OCT and polarization-sensitive SS-OCT (PS-SS-OCT) by using two hardware-synchronized high-speed data acquisition (DAQ) boards. The two DAQ boards read exactly the same imaging data for comparison. The measured system sensitivity at 8-bit depth is comparable to that for 14-bit acquisition when using the more sensitive of the available full analog input voltage ranges of the ADC. Ex-vivo structural and birefringence images of equine tendon indicate no significant differences between images acquired by the two DAQ boards suggesting that 8-bit DAQ boards can be employed to increase imaging speeds and reduce storage in clinical SS-OCT/PS-SS-OCT systems. One possible disadvantage is a reduced imaging dynamic range which can manifest itself as an increase in image artifacts due to strong Fresnel reflection.

  15. 99m-Tc-ubiquicidin scintigraphy in diagnosis of knee prosthesis infection and comparison with F-18 fluorodeoxy-glucose positron emission tomography/computed tomography.

    PubMed

    Kamaleshwaran, Koramadai Karuppusamy; Rajkumar, N; Mohanan, Vyshak; Kalarikal, Radhakrishnan; Shinto, Ajit Sugunan

    2015-01-01

    Total knee arthroplasty has witnessed a significant increase in recent years. Despite the advantages of this surgical procedure, it has some complications, the most serious of which is prosthetic infection. The discrimination of bacterial infections from sterile inflammatory processes is of great importance in the management of periprosthetic infection (PPI). Ubiquicidin (UBI) is a synthetic antimicrobial peptide fragment reported to be highly infection-specific. Tc99m-UBI has recently been reported to be a promising radiotracer for infection imaging. We report a case of left knee PPI diagnosed using 99mTc-UBI scintigraphy and compared with F-18 fluorodeoxy-glucose positron emission tomography.

  16. 99m-Tc-ubiquicidin scintigraphy in diagnosis of knee prosthesis infection and comparison with F-18 fluorodeoxy-glucose positron emission tomography/computed tomography

    PubMed Central

    Kamaleshwaran, Koramadai Karuppusamy; Rajkumar, N; Mohanan, Vyshak; Kalarikal, Radhakrishnan; Shinto, Ajit Sugunan

    2015-01-01

    Total knee arthroplasty has witnessed a significant increase in recent years. Despite the advantages of this surgical procedure, it has some complications, the most serious of which is prosthetic infection. The discrimination of bacterial infections from sterile inflammatory processes is of great importance in the management of periprosthetic infection (PPI). Ubiquicidin (UBI) is a synthetic antimicrobial peptide fragment reported to be highly infection-specific. Tc99m-UBI has recently been reported to be a promising radiotracer for infection imaging. We report a case of left knee PPI diagnosed using 99mTc-UBI scintigraphy and compared with F-18 fluorodeoxy-glucose positron emission tomography. PMID:26170572

  17. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws: A Phantom Study.

    PubMed

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M

    2015-08-01

    To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner.We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy.The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences.Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  18. Comparison of Multidetector Computed Tomography and Flat-Panel Computed Tomography Regarding Visualization of Cortical Fractures, Cortical Defects, and Orthopedic Screws

    PubMed Central

    Neubauer, Jakob; Benndorf, Matthias; Lang, Hannah; Lampert, Florian; Kemna, Lars; Konstantinidis, Lukas; Neubauer, Claudia; Reising, Kilian; Zajonc, Horst; Kotter, Elmar; Langer, Mathias; Goerke, Sebastian M.

    2015-01-01

    Abstract To compare the visualization of cortical fractures, cortical defects, and orthopedic screws in a dedicated extremity flat-panel computed tomography (FPCT) scanner and a multidetector computed tomography (MDCT) scanner. We used feet of European roe deer as phantoms for cortical fractures, cortical defects, and implanted orthopedic screws. FPCT and MDCT scans were performed with equivalent dose settings. Six observers rated the scans according to number of fragments, size of defects, size of defects opposite orthopedic screws, and the length of different screws. The image quality regarding depiction of the cortical bone was assessed. The gold standard (real number of fragments) was evaluated by autopsy. The correlation of reader assessment of fragments, cortical defects, and screws with the gold standard was similar for FPCT and MDCT. Three readers rated the subjective image quality of the MDCT to be higher, whereas the others showed no preferences. Although the image quality was rated higher in the MDCT than in the FPCT by 3 out of 6 observers, both modalities proved to be comparable regarding the visualization of cortical fractures, cortical defects, and orthopedic screws and of use to musculoskeletal radiology regarding fracture detection and postsurgical evaluation in our experimental setting. PMID:26252281

  19. Cognitive and Affective Effects of Various Types of Microcomputer Use by Preschoolers.

    ERIC Educational Resources Information Center

    Goodwin, Laura D.; And Others

    1986-01-01

    The effects of microcomputer use on preschoolers' knowledge of pre-reading concepts and attitudes toward microcomputers were investigated. Seventy-seven preschoolers were randomly assigned to three treatment conditions: (1) adult-assisted microcomputer instruction; (2) unassisted microcomputer use; and (3) no computer use. Analysis of pretest…

  20. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    SciTech Connect

    Morris, C. L.; Bourke, M.; Byler, D. D.; Chen, C. F.; Hogan, G.; Hunter, J. F.; Kwiatkowski, K.; Mariam, F. G.; McClellan, K. J.; Merrill, F.; Morley, D. J.; Saunders, A.

    2013-02-15

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. We also show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods have been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 {mu}m has been demonstrate, 20 {mu}m seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 {mu}m resolution but further development of sources, collimation, and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  1. The role of ultrasonography in the detection of adrenal masses: comparison with computed tomography and magnetic resonance imaging.

    PubMed

    Suzuki, Y; Sasagawa; Suzuki, H; Izumi, T; Kaneko, H; Nakada, T

    2001-01-01

    To compare detection rates of adrenal tumors by ultrasonography, computed tomography and magnetic resonance image, we studied 61 patients with adrenal tumor, who underwent adrenalectomy. In 45 (73.8%) of the 61 patients. adrenal tumor was detected by ultrasonography. However, computed tomography and magnetic resonance imaging could detect all adrenal tumors. All adrenal tumors measuring more than 3.0 cm in diameter were detected by ultrasonography, computed tomography and magnetic resonance image. When adrenal tumors were smaller than 3.0 cm. however, ultrasonography, computed tomography and magnetic resonance imaging correctly found adrenal tumors in 30 (65.2%) and 46 (100.0%) of 46 patients and 30 (100.0%) of 30 patients, respectively. These facts suggest that ultrasonography seems to be an effective diagnostic procedure for the prevention of overlooking adrenal tumors larger than 3.0 cm. PMID:11583338

  2. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    SciTech Connect

    Morris, Christopher L.; Bourke, Mark A.; Byler, Darrin D.; Chen, Ching-Fong; Hogan, Gary E.; Hunter, James F.; Kwiatkowski, Kris K.; Mariam, Fesseha G.; McClellan, Kenneth J.; Merrill, Frank E.; Morley, Deborah J.; Saunders, Alexander

    2013-02-11

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. Also, we show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods has been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomography on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.

  3. Comparison of Accuracy of Uncorrected and Corrected Sagittal Tomography in Detection of Mandibular Condyle Erosions: an Exvivo Study

    PubMed Central

    Naser, Asieh Zamani; Shirani, Amir Mansour; Hekmatian, Ehsan; Valiani, Ali; Ardestani, Pegah; Vali, Ava

    2010-01-01

    Background: Radiographic examination of TMJ is indicated when there are clinical signs of pathological conditions, mainly bone changes that may influence the diagnosis and treatment planning. The purpose of this study was to evaluate and to compare the validity and diagnostic accuracy of uncorrected and corrected sagittal tomographic images in the detection of simulated mandibular condyle erosions. Methods Simulated lesions were created in 10 dry mandibles using a dental round bur. Using uncorrected and corrected sagittal tomography techniques, mandibular condyles were imaged by a Cranex Tome X-ray unit before and after creating the lesions. The uncorrected and corrected tomography images were examined by two independent observers for absence or presence of a lesion. The accuracy for detecting mandibular condyle lesions was expressed as sensitivity, specificity, and validity values. Differences between the two radiographic modalities were tested by Wilcoxon for paired data tests. Inter-observer agreement was determined by Cohen's Kappa. Results: The sensitivity, specificity and validity were 45%, 85% and 30% in uncorrected sagittal tomographic images, respectively, and 70%, 92.5% and 60% in corrected sagittal tomographic images, respectively. There was a significant statistical difference between the accuracy of uncorrected and corrected sagittal tomography in detection of mandibular condyle erosions (P = 0.016). The inter-observer agreement was slight for uncorrected sagittal tomography and moderate for corrected sagittal tomography. Conclusion: The accuracy of corrected sagittal tomography is significantly higher than that of uncorrected sagittal tomography. Therefore, corrected sagittal tomography seems to be a better modality in detection of mandibular condyle erosions. PMID:22013461

  4. Microcomputers and neurobiology: a short review.

    PubMed

    Fraser, P J

    1985-12-01

    A brief history of the application of computing techniques emphasizes the two-part development with expensive minicomputers available in a few laboratories being added to by inexpensive microcomputers ubiquitously available. Computers are used for microscope control and plotting, serial section reconstruction, morphometric measurement, stereology, video image analysis, photometry and fluorescence microscopy. Basic principles are exemplified by considering nerve cell reconstruction. General principles of computerized electrical measurement including filtering, averaging and stimulus generation are discussed. Computerized waveform selection as used for spike discrimination, when considered along with computer control of electrode position and the growing availability of multichannel recording arrays, suggests a possible advance in automatic analyses. With the ability to process more complex waveforms successfully, electrophysiological data such as compound extracellular potentials may usefully replace the cleaner, but more limited intracellular data. Success with multichannel feedback controlled stimulators making paraplegics stand and walk point to a developing application with much potential.

  5. Microcomputer based software for biodynamic simulation

    NASA Technical Reports Server (NTRS)

    Rangarajan, N.; Shams, T.

    1993-01-01

    This paper presents a description of a microcomputer based software package, called DYNAMAN, which has been developed to allow an analyst to simulate the dynamics of a system consisting of a number of mass segments linked by joints. One primary application is in predicting the motion of a human occupant in a vehicle under the influence of a variety of external forces, specially those generated during a crash event. Extensive use of a graphical user interface has been made to aid the user in setting up the input data for the simulation and in viewing the results from the simulation. Among its many applications, it has been successfully used in the prototype design of a moving seat that aids in occupant protection during a crash, by aircraft designers in evaluating occupant injury in airplane crashes, and by users in accident reconstruction for reconstructing the motion of the occupant and correlating the impacts with observed injuries.

  6. Comparison of Physical Examination and Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography 4-6 Months After Radiotherapy to Assess Residual Head-and-Neck Cancer

    SciTech Connect

    Zundel, M. Tracy; Michel, Michelle A.; Schultz, Christopher J.; Maheshwari, Mohit; Wong, Stuart J.; Campbell, Bruce H.; Massey, Becky L.; Blumin, Joel; Wilson, J. Frank; Wang, Dian

    2011-12-01

    Purpose: To retrospectively compare fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and physical examination 4-6 months after radiotherapy for assessing residual head-and-neck cancer (HNC). Methods and Materials: From July 2002 through March 2006, 52 HNC patients underwent definitive radiotherapy or chemoradiotherapy. Categoric assessments of residual tumor by PET/CT and physical examination 4-6 months after therapy were correlated and compared with clinical outcomes. Pretreatment data, including tumor stage and primary site standardized uptake value, were also gathered retrospectively and correlated with clinical outcomes. Median follow-up time was 58 months. Results: Twenty-one patients had either locoregionally 'positive' (17 of 21) or 'equivocal' (4 of 21) PET/CT scans, whereas 31 patients had locoregionally negative scans. Four patients failed treatment and had biopsy-confirmed residual or recurrent local disease. All patients, including patients with locally suspicious scans or examinations who refused biopsies, were followed clinically for a minimum of 29 months after therapy, with no other cases of treatment failure detected during this time. No patient had residual nodal disease after therapy. Sensitivities of PET/CT vs. physical examination for early detection of treatment failure were 100% vs. 50%, whereas the specificities of the two modalities were 64.6% vs. 89.6%, respectively. Higher initial T stage and American Joint Commission on Cancer stage correlated with increased incidence of positive/equivocal PET/CT results and treatment failure. Maximal standardized uptake value was not predictive of any clinical outcome. Conclusions: A negative result on PET/CT obtained 4-6 months after radiotherapy is highly sensitive and correlates with successful locoregional control. Patients with negative scans may reasonably be spared invasive diagnostic procedures, such as biopsy and neck dissection, unless recurrent disease is suspected

  7. High resolution image processing on low-cost microcomputers

    NASA Technical Reports Server (NTRS)

    Miller, R. L.

    1993-01-01

    Recent advances in microcomputer technology have resulted in systems that rival the speed, storage, and display capabilities of traditionally larger machines. Low-cost microcomputers can provide a powerful environment for image processing. A new software program which offers sophisticated image display and analysis on IBM-based systems is presented. Designed specifically for a microcomputer, this program provides a wide-range of functions normally found only on dedicated graphics systems, and therefore can provide most students, universities and research groups with an affordable computer platform for processing digital images. The processing of AVHRR images within this environment is presented as an example.

  8. Direct Comparison of Virtual-Histology Intravascular Ultrasound and Optical Coherence Tomography Imaging for Identification of Thin-Cap Fibroatheroma

    PubMed Central

    Brown, Adam J.; Obaid, Daniel R.; Costopoulos, Charis; Parker, Richard A.; Calvert, Patrick A.; Teng, Zhongzhao; Hoole, Stephen P.; West, Nick E.J.; Goddard, Martin

    2015-01-01

    Background— Although rupture of thin-cap fibroatheroma (TCFA) underlies most myocardial infarctions, reliable TCFA identification remains challenging. Virtual-histology intravascular ultrasound (VH-IVUS) and optical coherence tomography (OCT) can assess tissue composition and classify plaques. However, direct comparisons between VH-IVUS and OCT are lacking and it remains unknown whether combining these modalities improves TCFA identification. Methods and Results— Two hundred fifty-eight regions-of-interest were obtained from autopsied human hearts, with plaque composition and classification assessed by histology and compared with coregistered ex vivo VH-IVUS and OCT. Sixty-seven regions-of-interest were classified as fibroatheroma on histology, with 22 meeting criteria for TCFA. On VH-IVUS, plaque (10.91±4.82 versus 8.42±4.57 mm2; P=0.01) and necrotic core areas (1.59±0.99 versus 1.03±0.85 mm2; P=0.02) were increased in TCFA versus other fibroatheroma. On OCT, although minimal fibrous cap thickness was similar (71.8±44.1 μm versus 72.6±32.4; P=0.30), the number of continuous frames with fibrous cap thickness ≤85 μm was higher in TCFA (6.5 [1.75–11.0] versus 2.0 [0.0–7.0]; P=0.03). Maximum lipid arc on OCT was an excellent discriminator of fibroatheroma (area under the curve, 0.92; 95% confidence interval, 0.87–0.97) and TCFA (area under the curve, 0.86; 95% confidence interval, 0.81–0.92), with lipid arc ≥80° the optimal cut-off value. Using existing criteria, the sensitivity, specificity, and diagnostic accuracy for TCFA identification was 63.6%, 78.1%, and 76.5% for VH-IVUS and 72.7%, 79.8%, and 79.0% for OCT. Combining VH-defined fibroatheroma and fibrous cap thickness ≤85 μm over 3 continuous frames improved TCFA identification, with diagnostic accuracy of 89.0%. Conclusions— Both VH-IVUS and OCT can reliably identify TCFA, although OCT accuracy may be improved using lipid arc ≥80° and fibrous cap thickness ≤85 μm over 3

  9. Comparison of Anterior Segment Optical Tomography Parameters Measured Using a Semi-Automatic Software to Standard Clinical Instruments

    PubMed Central

    Ang, Marcus; Chong, Wesley; Huang, Huiqi; Tay, Wan Ting; Wong, Tien Yin; He, Ming-Guang; Aung, Tin; Mehta, Jodhbir S.

    2013-01-01

    Objective To compare anterior segment parameters measured using a semi-automatic software (Zhongshan Angle Assessment Program, ZAP) applied to anterior segment optical coherence tomography (AS-OCT) images, with commonly used instruments. Methods Cross-sectional study of a total of 1069 subjects (1069 eyes) from three population-based studies of adults aged 40–80 years. All subjects underwent AS-OCT imaging and ZAP software was applied to determine anterior chamber depth (ACD), central corneal thickness (CCT), anterior and keratometry (K) – readings. These were compared to auto-refraction, keratometry and ocular biometry measured using an IOLMaster, ultrasound pachymeter and auto-refractor respectively. Agreements between AS-OCT (ZAP) and clinical instrument modalities were described using Bland-Altman, 95% limits of agreement (LOA). Results The mean age of our subjects was 56.9±9.5 years and 50.9% were male. The mean AS-OCT (ZAP) parameters of our study cohort were: ACD 3.29±0.35 mm, CCT 560.75±35.07 µm; K-reading 46.79±2.72 D. There was good agreement between the measurements from ZAP analysis and each instrument and no violations in the assumptions of the LOA; albeit with a systematic bias for each comparison: AS-OCT consistently measured a deeper ACD compared to IOLMaster (95% LOA −0.24, 0.55); and a thicker CCT for the AS-OCT compared to ultrasound pachymetry (16.8±0.53 µm 95% LOA −17.3, 50.8). AS-OCT had good agreement with auto-refractor with at least 95% of the measurements within the prediction interval (P value <0.001). Conclusion This study demonstrates that there is good agreement between the measurements from the AS-OCT (ZAP) and conventional tools. However, small systematic biases remain that suggest that these measurement tools may not be interchanged. PMID:23750265

  10. Impact of dynamic specimen shape evolution on the atom probe tomography results of doped epitaxial oxide multilayers: Comparison of experiment and simulation

    SciTech Connect

    Madaan, Nitesh; Nandasiri, Manjula; Devaraj, Arun; Bao, Jie; Xu, Zhijie; Thevuthasan, Suntharampillai

    2015-08-31

    The experimental atom probe tomography (APT) results from two different specimen orientations (top-down and sideways) of a high oxygen ion conducting Samaria-doped-ceria/Scandia-stabilized-zirconia multilayer thin film solid oxide fuel cell electrolyte was compared with level-set method based field evaporation simulations for the same specimen orientations. This experiment-simulation comparison explains the dynamic specimen shape evolution and ion trajectory aberrations that can induce density artifacts in final reconstruction, leading to inaccurate estimation of interfacial intermixing. This study highlights the importance of comparing experimental results with field evaporation simulations when using APT to study oxide heterostructure interfaces.

  11. Absolute quantitation of iodine-123 epidepride kinetics using single-photon emission tomography: comparison with carbon-11 epidepride and positron emission tomography.

    PubMed

    Almeida, P; Ribeiro, M J; Bottlaender, M; Loc'h, C; Langer, O; Strul, D; Hugonnard, P; Grangeat, P; Mazière, B; Bendriem, B

    1999-12-01

    Epidepride labelled with iodine-123 is a suitable probe for the in vivo imaging of striatal and extrastriatal dopamine D2 receptors using single-photon emission tomography (SPET). Recently, this molecule has also been labelled with carbon-11. The goal of this work was to develop a method allowing the in vivo quantification of radioactivity uptake in baboon brain using SPET and to validate it using positron emission tomography (PET). SPET studies were performed in Papio anubis baboons using 123I-epidepride. Emission and transmission measurements were acquired on a dual-headed system with variable head angulation and low-energy ultra-high resolution (LEUHR) collimation. The imaging protocol consisted of one transmission measurement (24 min, heads at 90 degrees), obtained with two sliding line sources of gadolinium-153 prior to injection of 0.21-0.46 GBq of 123I-epidepride, and 12 emission measurements starting 5 min post injection. For scatter correction (SC) we used a dual-window method adapted to 123I. Collimator blurring correction (CBC) was done by deconvolution in Fourier space and attenuation correction (AT) was applied on a preliminary (CBC) filtered back-projection reconstruction using 12 iterations of a preconditioned, regularized minimal residual algorithm. For each reconstruction, a calibration factor was derived from a uniform cylinder filled with a 123I solution of a known radioactivity concentration. Calibration and baboon images were systematically built with the same reconstruction parameters. Uncorrected (UNC) and (AT), (SC + AT) and (SC + CBC + AT) corrected images were compared. PET acquisitions using 0.11-0.44 GBq of 11C-epidepride were performed on the same baboons and used as a reference. The radioactive concentrations expressed in percent of the injected dose per 100 ml (% ID/100 ml) obtained after (SC + CBC + AT) in SPET are in good agreement with those obtained with PET and 11C-epidepride. A method for the in vivo absolute quantitation of 123

  12. A comparison study of 11C-methionine and 18F-fluorodeoxyglucose positron emission tomography-computed tomography scans in evaluation of patients with recurrent brain tumors

    PubMed Central

    Sharma, Rajnish; D’Souza, Maria; Jaimini, Abhinav; Hazari, Puja Panwar; Saw, Sanjeev; Pandey, Santosh; Singh, Dinesh; Solanki, Yachna; Kumar, Nitin; Mishra, Anil K.; Mondal, Anupam

    2016-01-01

    Introduction: 11C-methonine ([11C]-MET) positron emission tomography-computed tomography (PET-CT) is a well-established technique for evaluation of tumor for diagnosis and treatment planning in neurooncology. [11C]-MET reflects amino acid transport and has been shown to be more sensitive than magnetic resonance imaging (MRI) in stereotactic biopsy planning. This study compared fluorodeoxyglucose (FDG) PET-CT and MET PET-CT in the detection of various brain tumors. Materials and Methods: Sixty-four subjects of brain tumor treated by surgery, chemotherapy, and/or radiotherapy were subjected to [18F]-FDG, [11C]-MET, and MRI scan. The lesion was analyzed semiquantitatively using tumor to normal contralateral ratio. The diagnosis was confirmed by surgery, stereotactic biopsy, clinical follow-up, MRI, or CT scans. Results: Tumor recurrence was found in 5 out of 22 patients on [F-18] FDG scan while [11C]-MET was able to detect recurrence in 18 out of 22 patients in low-grade gliomas. Two of these patients were false positive for the presence of recurrence of tumor and later found to be harboring necrosis. Among oligodendroglioma, medulloblastoma and high-grade glioma out of 42 patients 39 were found to be concordant MET and FDG scans. On semiquantitative analysis, mean T/NT ratio was found to be 2.96 ± 0.94 for lesions positive for recurrence of tumors and 1.18 ± 0.74 for lesions negative for recurrence of tumor on [11C]-MET scan. While the ratio for FDG scan on semiquantitative analysis was found to be 2.05 ± 1.04 for lesions positive for recurrence of tumors and 0.52 ± 0.15 for lesions negative for recurrence of tumors. Conclusion: The study highlight that [11C]-MET is superior to [18F]-FDG PET scans to detect recurrence in low-grade glioma. A cut-off value of target to nontarget value of 1.47 is a useful parameter to distinguish benign from malignant lesion on an [11C]-MET Scan. Both [18F]-FDG and [11C]-MET scans were found to be useful in high-grade astrocytoma

  13. Investigating Electromagnetic Induction through a Microcomputer-Based Laboratory.

    ERIC Educational Resources Information Center

    Trumper, Ricardo; Gelbman, Moshe

    2000-01-01

    Describes a microcomputer-based laboratory experiment designed for high school students that very accurately analyzes Faraday's law of electromagnetic induction, addressing each variable separately while the others are kept constant. (Author/CCM)

  14. Teaching WP and DP with CP/M-Based Microcomputers.

    ERIC Educational Resources Information Center

    Bartholome, Lloyd W.

    1982-01-01

    The use of CP/M (Control Program Monitor)-based microcomputers in teaching word processing and data processing is explored. The system's advantages, variations, dictionary software, and future are all discussed. (CT)

  15. Applications of Microcomputers in the Teaching of Physics 6502 Software.

    ERIC Educational Resources Information Center

    Marsh, David P.

    1980-01-01

    Described is a variety of uses of the microcomputer when coupled with software available for systems using 6502 microprocessors. Included are several computer programs which exhibit some of the possibilities for programing the 6502 microprocessors. (DS)

  16. A Microcomputer-Assisted Presentation of Atomic Orbitals.

    ERIC Educational Resources Information Center

    Petrich, James A.

    1981-01-01

    A program written for the Apple II microcomputer that plots the "one-S" orbital of an atom is described. The material is used to move from the Bohr model of the atom to the quantum mechanical description. (MP)

  17. A Laboratory Data Collection Microcomputer for Handicapped Science Students.

    ERIC Educational Resources Information Center

    Lunney, David; Morrison, Robert C.

    1982-01-01

    A microcomputer-based Universal Laboratory Training and Research Aid (ULTRA) provides meaningful laboratory access to blind students and students with upper limb disabilities. Using ULTRA, blind students can perform chemical experiments independently. (CL)

  18. Computer Center: Setting Up a Microcomputer Center--1 Person's Perspective.

    ERIC Educational Resources Information Center

    Duhrkopf, Richard, Ed.; Collins, Michael, A. J., Ed.

    1988-01-01

    Considers eight components to be considered in setting up a microcomputer center for use with college classes. Discussions include hardware, software, physical facility, furniture, technical support, personnel, continuing financial expenditures, and security. (CW)

  19. Learning Scientific Reasoning Skills in Microcomputer-Based Laboratories.

    ERIC Educational Resources Information Center

    Friedler, Yael; And Others

    1990-01-01

    The impact of enhanced observation or enhanced prediction on scientific reasoning about heat energy and temperature problems was investigated. Instruction was successful in improving prediction and observation skills in the microcomputer-based laboratory environment. (CW)

  20. Evaluating Microcomputer Access Technology for Use by Visually Impaired Students.

    ERIC Educational Resources Information Center

    Ruconich, Sandra

    1984-01-01

    The article outlines advantages and limitations of five types of access to microcomputer technology for visually impaired students: electronic braille, paper braille, Optacon, synthetic speech, and enlarged print. Additional considerations in access decisions are noted. (CL)

  1. Modeling Steady-State Groundwater Flow Using Microcomputer Spreadsheets.

    ERIC Educational Resources Information Center

    Ousey, John Russell, Jr.

    1986-01-01

    Describes how microcomputer spreadsheets are easily adapted for use in groundwater modeling. Presents spreadsheet set-ups and the results of five groundwater models. Suggests that this approach can provide a basis for demonstrations, laboratory exercises, and student projects. (ML)

  2. Comparison of retinal thickness by Fourier-domain optical coherence tomography and OCT retinal image analysis software segmentation analysis derived from Stratus optical coherence tomography images

    NASA Astrophysics Data System (ADS)

    Tátrai, Erika; Ranganathan, Sudarshan; Ferencz, Mária; Debuc, Delia Cabrera; Somfai, Gábor Márk

    2011-05-01

    Purpose: To compare thickness measurements between Fourier-domain optical coherence tomography (FD-OCT) and time-domain OCT images analyzed with a custom-built OCT retinal image analysis software (OCTRIMA). Methods: Macular mapping (MM) by StratusOCT and MM5 and MM6 scanning protocols by an RTVue-100 FD-OCT device are performed on 11 subjects with no retinal pathology. Retinal thickness (RT) and the thickness of the ganglion cell complex (GCC) obtained with the MM6 protocol are compared for each early treatment diabetic retinopathy study (ETDRS)-like region with corresponding results obtained with OCTRIMA. RT results are compared by analysis of variance with Dunnett post hoc test, while GCC results are compared by paired t-test. Results: A high correlation is obtained for the RT between OCTRIMA and MM5 and MM6 protocols. In all regions, the StratusOCT provide the lowest RT values (mean difference 43 +/- 8 μm compared to OCTRIMA, and 42 +/- 14 μm compared to RTVue MM6). All RTVue GCC measurements were significantly thicker (mean difference between 6 and 12 μm) than the GCC measurements of OCTRIMA. Conclusion: High correspondence of RT measurements is obtained not only for RT but also for the segmentation of intraretinal layers between FD-OCT and StratusOCT-derived OCTRIMA analysis. However, a correction factor is required to compensate for OCT-specific differences to make measurements more comparable to any available OCT device.

  3. Comparison of the Diagnostic Image Quality of the Canine Maxillary Dentoalveolar Structures Obtained by Cone Beam Computed Tomography and 64-Multidetector Row Computed Tomography.

    PubMed

    Soukup, Jason W; Drees, Randi; Koenig, Lisa J; Snyder, Christopher J; Hetzel, Scott; Miles, Chanda R; Schwarz, Tobias

    2015-01-01

    The objective of this blinded study was to validate the use of cone beam computed tomography (C) for imaging of the canine maxillary dentoalveolar structures by comparing its diagnostic image quality with that of 64-multidetector row CT Sagittal slices of a tooth-bearing segment of the maxilla of a commercially purchased dog skull embedded in methylmethacrylate were obtained along a line parallel with the dental arch using a commercial histology diamond saw. The slice of tooth-bearing bone that best depicted the dentoalveolar structures was chosen and photographed. The maxillary segment was imaged with cone beam CT and 64-multidetector row CT. Four blinded evaluators compared the cone beam CT and 64-multidetector row CT images and image quality was scored as it related to the anatomy of dentoalveolar structures. Trabecular bone, enamel, dentin, pulp cavity, periodontal ligament space, and lamina dura were scored In addition, a score depicting the evaluators overall impression of the image was recorded. Images acquired with cone beam CT were found to be significantly superior in image quality to images acquired with 64-multidetector row CT overall, and in all scored categories. In our study setting cone beam CT was found to be a valid and clinically superior imaging modality for the canine maxillary dentoalveolar structures when compared to 64-multidetector row CT. PMID:26415384

  4. Microcomputer-controlled world time display for public area viewing

    NASA Astrophysics Data System (ADS)

    Yep, S.; Rashidian, M.

    1982-05-01

    The design, development, and implementation of a microcomputer-controlled world clock is discussed. The system, designated international Time Display System (ITDS), integrates a Geochron Calendar Map and a microcomputer-based digital display to automatically compensate for daylight savings time, leap year, and time zone differences. An in-depth technical description of the design and development of the electronic hardware, firmware, and software systems is provided. Reference material on the time zones, fabrication techniques, and electronic subsystems are also provided.

  5. Experimental comparison of grating- and propagation-based hard X-ray phase tomography of soft tissue

    NASA Astrophysics Data System (ADS)

    Lang, S.; Zanette, I.; Dominietto, M.; Langer, M.; Rack, A.; Schulz, G.; Le Duc, G.; David, C.; Mohr, J.; Pfeiffer, F.; Müller, B.; Weitkamp, T.

    2014-10-01

    When imaging soft tissues with hard X-rays, phase contrast is often preferred over conventional attenuation contrast due its superior sensitivity. However, it is unclear which of the numerous phase tomography methods yields the optimized results at given experimental conditions. Therefore, we quantitatively compared the three phase tomography methods implemented at the beamline ID19 of the European Synchrotron Radiation Facility: X-ray grating interferometry (XGI), and propagation-based phase tomography, i.e., single-distance phase retrieval (SDPR) and holotomography (HT), using cancerous tissue from a mouse model and an entire heart of a rat. We show that for both specimens, the spatial resolution derived from the characteristic morphological features is about a factor of two better for HT and SDPR compared to XGI, whereas the XGI data generally exhibit much better contrast-to-noise ratios for the anatomical features. Moreover, XGI excels in fidelity of the density measurements, and is also more robust against low-frequency artifacts than HT, but it might suffer from phase-wrapping artifacts. Thus, we can regard the three phase tomography methods discussed as complementary. The application will decide which spatial and density resolutions are desired, for the imaging task and dose requirements, and, in addition, the applicant must choose between the complexity of the experimental setup and the one of data processing.

  6. Experimental comparison of grating- and propagation-based hard X-ray phase tomography of soft tissue

    SciTech Connect

    Lang, S.; Schulz, G.; Müller, B.; Zanette, I.; Dominietto, M.; Langer, M.; Rack, A.; Le Duc, G.; David, C.; Mohr, J.; Pfeiffer, F.; Weitkamp, T.

    2014-10-21

    When imaging soft tissues with hard X-rays, phase contrast is often preferred over conventional attenuation contrast due its superior sensitivity. However, it is unclear which of the numerous phase tomography methods yields the optimized results at given experimental conditions. Therefore, we quantitatively compared the three phase tomography methods implemented at the beamline ID19 of the European Synchrotron Radiation Facility: X-ray grating interferometry (XGI), and propagation-based phase tomography, i.e., single-distance phase retrieval (SDPR) and holotomography (HT), using cancerous tissue from a mouse model and an entire heart of a rat. We show that for both specimens, the spatial resolution derived from the characteristic morphological features is about a factor of two better for HT and SDPR compared to XGI, whereas the XGI data generally exhibit much better contrast-to-noise ratios for the anatomical features. Moreover, XGI excels in fidelity of the density measurements, and is also more robust against low-frequency artifacts than HT, but it might suffer from phase-wrapping artifacts. Thus, we can regard the three phase tomography methods discussed as complementary. The application will decide which spatial and density resolutions are desired, for the imaging task and dose requirements, and, in addition, the applicant must choose between the complexity of the experimental setup and the one of data processing.

  7. The Incremental Prognostic Value of Cardiac Computed Tomography in Comparison with Single-Photon Emission Computed Tomography in Patients with Suspected Coronary Artery Disease

    PubMed Central

    Lee, Heesun; Yoon, Yeonyee E.; Park, Jun-Bean; Kim, Hack-Lyoung; Park, Hyo Eun; Lee, Seung-Pyo; Kim, Hyung-Kwan; Choi, Su-Yeon; Kim, Yong-Jin; Cho, Goo-Yeong; Zo, Joo-Hee; Sohn, Dae-Won

    2016-01-01

    Background Coronary computed tomographic angiography (CCTA) facilitates comprehensive evaluation of coronary artery disease (CAD), including plaque characterization, and can provide additive diagnostic value to single-photon emission computed tomography (SPECT). However, data regarding the incremental prognostic value of CCTA to SPECT remain sparse. We evaluated the independent and incremental prognostic value of CCTA, as compared with clinical risk factors and SPECT. Materials and methods A total of 1,077 patients with suspected CAD who underwent both SPECT and cardiac CT between 2004 and 2012 were enrolled retrospectively. Presence of reversible or fixed perfusion defect (PD) and summed stress score were evaluated on SPECT. Presence, extent of coronary atherosclerosis and diameter stenosis (DS) were evaluated on CCTA. Plaque composition was categorized as non-calcified, mixed, or calcified according to the volume of calcified component (>130 Hounsfield Units). Patients were followed up for the occurrence of adverse cardiac events including cardiac death, non-fatal myocardial infarction, unstable angina, and late revascularization (>90 days after imaging studies). Results During follow-up (median 23 months), adverse cardiac events were observed in 71 patients (6.6%). When adjusted for clinical risk factors and SPECT findings, the presence of any coronary plaque, any plaque in ≥3 segments, coronary artery calcium score (CACS) ≥400, a plaque ≥50% DS, presence of non-calcified plaque (NCP) or mixed plaque (MP), and NCP/MP in ≥2 segments were independent predictors of adverse cardiac events; however, the presence of calcified plaque (CP) was not. Conventional CCTA findings, including CACS ≥400 and a plaque ≥50% DS, demonstrated incremental prognostic value over clinical risk factors and SPECT (χ² 54.19 to 101.03; p <0.001). Addition of NCP/MP in ≥2 segments resulted in further significantly improved prediction (χ² 101.03 to 113.29; p <0

  8. Pulmonary Ventilation Imaging Based on 4-Dimensional Computed Tomography: Comparison With Pulmonary Function Tests and SPECT Ventilation Images

    SciTech Connect

    Yamamoto, Tokihiro; Kabus, Sven; Lorenz, Cristian; Mittra, Erik; Hong, Julian C.; Chung, Melody; Eclov, Neville; To, Jacqueline; Diehn, Maximilian; Loo, Billy W.; Keall, Paul J.

    2014-10-01

    Purpose: 4-dimensional computed tomography (4D-CT)-based pulmonary ventilation imaging is an emerging functional imaging modality. The purpose of this study was to investigate the physiological significance of 4D-CT ventilation imaging by comparison with pulmonary function test (PFT) measurements and single-photon emission CT (SPECT) ventilation images, which are the clinical references for global and regional lung function, respectively. Methods and Materials: In an institutional review board–approved prospective clinical trial, 4D-CT imaging and PFT and/or SPECT ventilation imaging were performed in thoracic cancer patients. Regional ventilation (V{sub 4DCT}) was calculated by deformable image registration of 4D-CT images and quantitative analysis for regional volume change. V{sub 4DCT} defect parameters were compared with the PFT measurements (forced expiratory volume in 1 second (FEV{sub 1}; % predicted) and FEV{sub 1}/forced vital capacity (FVC; %). V{sub 4DCT} was also compared with SPECT ventilation (V{sub SPECT}) to (1) test whether V{sub 4DCT} in V{sub SPECT} defect regions is significantly lower than in nondefect regions by using the 2-tailed t test; (2) to quantify the spatial overlap between V{sub 4DCT} and V{sub SPECT} defect regions with Dice similarity coefficient (DSC); and (3) to test ventral-to-dorsal gradients by using the 2-tailed t test. Results: Of 21 patients enrolled in the study, 18 patients for whom 4D-CT and either PFT or SPECT were acquired were included in the analysis. V{sub 4DCT} defect parameters were found to have significant, moderate correlations with PFT measurements. For example, V{sub 4DCT}{sup HU} defect volume increased significantly with decreasing FEV{sub 1}/FVC (R=−0.65, P<.01). V{sub 4DCT} in V{sub SPECT} defect regions was significantly lower than in nondefect regions (mean V{sub 4DCT}{sup HU} 0.049 vs 0.076, P<.01). The average DSCs for the spatial overlap with SPECT ventilation defect regions were only moderate (V

  9. Qualitative comparison of bremsstrahlung X-rays and 800 MeV protons for tomography of urania fuel pellets

    DOE PAGES

    Morris, Christopher L.; Bourke, Mark A.; Byler, Darrin D.; Chen, Ching-Fong; Hogan, Gary E.; Hunter, James F.; Kwiatkowski, Kris K.; Mariam, Fesseha G.; McClellan, Kenneth J.; Merrill, Frank E.; et al

    2013-02-11

    We present an assessment of x-rays and proton tomography as tools for studying the time dependence of the development of damage in fuel rods. Also, we show data taken with existing facilities at Los Alamos National Laboratory that support this assessment. Data on surrogate fuel rods has been taken using the 800 MeV proton radiography (pRad) facility at the Los Alamos Neutron Science Center (LANSCE), and with a 450 keV bremsstrahlung X-ray tomography facility. The proton radiography pRad facility at LANSCE can provide good position resolution (<70 μm has been demonstrate, 20 μm seems feasible with minor changes) for tomographymore » on activated fuel rods. Bremsstrahlung x-rays may be able to provide better than 100 μm resolution but further development of sources, collimation and detectors is necessary for x-rays to deal with the background radiation for tomography of activated fuel rods.« less

  10. Modified Laser and Thermos cell calculations on microcomputers

    SciTech Connect

    Shapiro, A.; Huria, H.C.

    1987-01-01

    In the course of designing and operating nuclear reactors, many fuel pin cell calculations are required to obtain homogenized cell cross sections as a function of burnup. In the interest of convenience and cost, it would be very desirable to be able to make such calculations on microcomputers. In addition, such a microcomputer code would be very helpful for educational course work in reactor computations. To establish the feasibility of making detailed cell calculations on a microcomputer, a mainframe cell code was compiled and run on a microcomputer. The computer code Laser, originally written in Fortran IV for the IBM-7090 class of mainframe computers, is a cylindrical, one-dimensional, multigroup lattice cell program that includes burnup. It is based on the MUFT code for epithermal and fast group calculations, and Thermos for the thermal calculations. There are 50 fast and epithermal groups and 35 thermal groups. Resonances are calculated assuming a homogeneous system and then corrected for self-shielding, Dancoff, and Doppler by self-shielding factors. The Laser code was converted to run on a microcomputer. In addition, the Thermos portion of Laser was extracted and compiled separately to have available a stand alone thermal code.

  11. Electronic Fetal Monitoring by Microcomputer: A Clinical Application

    PubMed Central

    Lichten, Edward M.

    1981-01-01

    Using recent advances in microcomputer technology, a system for the continuous, direct processing of fetal monitor information is installed in Sinai Hospital. The basic system consists of an Apple IIR microcomputer with accessories readily available at local computer stores. Eight fetal monitors are connected to the computer system by cable. Monitor tracings, similar in quality to the original, are displayed at the central unit and at remote locations throughout the labor and delivery areas. This information can also be transmitted to physicians' homes and reproduced on a multi-copy graphic printer. Two benefits with this system are noted. First, this application of microcomputer technology promotes the rapid dissemination of information to physicians and staff. Second, medical record storage can be improved by the graphic printer's copies.

  12. [Comparison of B-mode ultrasonography and computed tomography in the evaluation of maxillary sinusitis in pediatric patients].

    PubMed

    Mori, Aya; Nakayama, Tsuguhisa; Tsukidate, Toshiharu; Hirabayashi, Hideki; Haruna, Shinichi

    2014-01-01

    The use of ultrasonography in the diagnosis of maxillary sinusitis in pediatric patients has been reported recently because of the improvement of the accuracy of ultrasound technology. We thus compared B-mode ultrasonography and computed tomography in the diagnosis of maxillary sinusitis in pediatric patients. Thirty-six maxillary sinuses in 18 patients (10 females, 8 males, ages ranging from 7-15 years with an average age of 10.4 years) were examined. Ultrasonography of the maxillary sinus was performed in the horizontal and the vertical direction. Paranasal computed tomography and B-mode ultrasonography were performed within a few days. In some of these patients the maxillary sinuses were examined with a fiberscope. Sensitivity, specificity, false-positive, false-negative, positive predictive value and negative predictive value of B-mode ultrasonography compared with computed tomography were 92.6%, 100%, 0%, 7.4%, 100% and 81.8%, respectively. It appeared that ultrasonography was more sensitive than X-ray imaging, because the sensitivity and specificity of X-ray imaging of the maxillary sinus in pediatric patients compared with CT was reportedly 70-80%. A meaningful correlation of ultrasonography and CT was accepted as an assessment of desease severity. There are some problems with diagnosis by ultrasonography. There is no differentiation of mucosal thicking, cyst and discharge and imaging are less useful in pediatric patients. Because of these reasons, clinical sign and views in the nose are important for a correct diagnosis in pediatric patients. Furthermore, the most suitable age range to diagnose maxillary sinusitis correctly in pediatric patients must be examined. PMID:24601097

  13. Microcomputer authoring systems: valuable tools for health educators.

    PubMed

    Whiteside, M F; Whiteside, J A

    Writing courseware with the aid of an authoring system is a bold step that can bring together the health education content expert and the power of the microcomputer. The microcomputer can be programmed to present essential knowledge to students in a low pressure setting, specifically geared to their levels of comprehension and rates of progression. Microcomputer-based simulations and patient management problems seem suited to the task helping students develop adequate problem-solving skills in health education (Lewis, 1983; Peterson, 1984). Furthermore, many lecture hours can be replaced by an infinitely patient tutor with which students can interact at their convenience. Creating self-study materials delivered via microcomputer is also a step toward providing the most effective type of learning experiences for individual students. Despite the fact that putting authoring systems in the hands of well-informed content specialists may meet a number of pressing needs in health education, there is one drawback. Authoring systems have a built-in pedagogical structure that, to some extent, dictates the design of the lesson. However, spending time in the evaluation process prior to purchase will enable educators to identify a system that can be used to develop courseware that very closely matches the desires of the author. Integrating microcomputer courseware into health education courses is certainly an attractive solution to some of the educational problems faced in health education today. An authoring system can be used to develop courseware that can substituted for lectures on basic concepts. In addition, students will have more opportunities to develop the ability to apply, in problem-solving situations, the factual knowledge they are learning before they are responsible for making judgments in real-life situations. The time is ripe, then, for health educators to investigate how authoring systems can help them utilize the technology of the microcomputer to improve

  14. SPECT imaging of Moyamoya disease using /sup 99m/Tc-HM-PAO. Comparison with computed tomography findings

    SciTech Connect

    Mountz, J.M.; Foster, N.L.; Ackermann, R.J.; Bluemlein, L.; Petry, N.A.; Kuhl, D.E.

    1988-10-01

    /sup 99m/Tc-HM-PAO was used to evaluate regional cerebral blood flow in a 26-year-old woman with Moyamoya disease. This patient had an 18-month history of recurrent neurologic deficits and had angiographic evidence of Moyamoya disease. She had used oral contraceptives and cigarettes, but had no other risk factors for stroke. Single photon emission computed tomographic images showed bilateral and asymmetric reductions in blood flow to anterior and lateral brain regions. These findings correlated better with clinical symptomatology and suggested more extensive brain involvement than did computed tomography.

  15. Diagnosis of Alzheimer-type dementia: a preliminary comparison of positron emission tomography and proton magnetic resonance

    SciTech Connect

    Friedland, R.P.; Budinger, T.F.; Brant-Zawadzki, M.; Jagust, W.J.

    1984-11-16

    The use of positron emission tomography with (18F)-2-fluoro-2-deoxy-D-glucose (FDG) to study glucose metabolism in dementia is described and compared with the use of magnetic resonance imaging. These studies suggest that physiological imaging with PET may be superior to MR as it is currently used in the diagnosis of dementia-like diseases. Pet is currently limited to a few centers; however, single photon emission CT can provide regional physiological data without the need for a local cyclotron. 15 references, 2 tables.

  16. A microcomputer system designed for psychological and behavioural experiments.

    PubMed

    Popplewell, D A; Burton, M J

    1985-05-01

    This paper describes a relatively cheap MC6809-based microcomputer designed to run experiments in real-time, and to use the hardware and software facilities of a larger (HOST) computer. Each microcomputer is capable of controlling a wide range of psychological and behavioural experiments, and includes 32K RAM, 4K EPROM, 32 digital input lines, 32 digital output lines, analogue/digital converters, and programmable timers. Any programming language may be used, providing a cross-compiler generating MC6809 executable code exists for the HOST. Following over a year of use we can confirm that this system provides an effective method of running psychological and behavioural experiments.

  17. Microcomputers and Teacher Education. OATE-OACTE Monograph Series No. 10.

    ERIC Educational Resources Information Center

    Murphy, Linda B., Ed; Warger, Cynthia L., Ed.

    The six articles presented in this monograph discuss the role of microcomputers in teacher education: (1) "What Teachers and Their Students Should Know about Microcomputers" (Michael T. Battista) (2) "Promoting 'Computing Literacy' for Teacher Educators" (Keith E. Bernhard); (3) "Microcomputers in Education: A Review of Research" (Lynn Lehner and…

  18. Managerial Applications of the Microcomputer for Special Education Teachers. For Your Information.

    ERIC Educational Resources Information Center

    Griffith-Sheriff, Denise; Walter, Virginia

    An overview of the uses of microcomputers in special education management is provided. Following a list of nine applications of microcomputers to educational management is a brief description of microcomputers currently used in education. A listing of five firms currently marketing special education management software includes information of…

  19. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    SciTech Connect

    Darvin, M E; Richter, H; Zhu, Y J; Meinke, M C; Knorr, F; Lademann, J; Gonchukov, S A; Koenig, K

    2014-07-31

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted. (laser biophotonics)

  20. Comparison of in vivo and ex vivo laser scanning microscopy and multiphoton tomography application for human and porcine skin imaging

    NASA Astrophysics Data System (ADS)

    Darvin, M. E.; Richter, H.; Zhu, Y. J.; Meinke, M. C.; Knorr, F.; Gonchukov, S. A.; Koenig, K.; Lademann, J.

    2014-07-01

    Two state-of-the-art microscopic optical methods, namely, confocal laser scanning microscopy in the fluorescence and reflectance regimes and multiphoton tomography in the autofluorescence and second harmonic generation regimes, are compared for porcine skin ex vivo and healthy human skin in vivo. All skin layers such as stratum corneum (SC), stratum spinosum (SS), stratum basale (SB), papillary dermis (PD) and reticular dermis (RD) as well as transition zones between these skin layers are measured noninvasively at a high resolution, using the above mentioned microscopic methods. In the case of confocal laser scanning microscopy (CLSM), measurements in the fluorescence regime were performed by using a fluorescent dye whose topical application on the surface is well suited for the investigation of superficial SC and characterisation of the skin barrier function. For investigations of deeply located skin layers, such as SS, SB and PD, the fluorescent dye must be injected into the skin, which markedly limits fluorescence measurements using CLSM. In the case of reflection CLSM measurements, the obtained results can be compared to the results of multiphoton tomography (MPT) for all skin layers excluding RD. CLSM cannot distinguish between dermal collagen and elastin measuring their superposition in the RD. By using MPT, it is possible to analyse the collagen and elastin structures separately, which is important for the investigation of anti-aging processes. The resolution of MPT is superior to CLSM. The advantages and limitations of both methods are discussed and the differences and similarities between human and porcine skin are highlighted.

  1. In vitro comparison of cone beam computed tomography with different voxel sizes for detection of simulated external root resorption.

    PubMed

    Neves, Frederico S; de Freitas, Deborah Q; Campos, Paulo S F; de Almeida, Solange M; Haiter-Neto, Francisco

    2012-09-01

    The present study compared the efficacy of cone beam computed tomography using different voxel sizes in the diagnosis of simulated external root resorption. The presence or absence of simulated defects on buccal, mesial and distal root surfaces of 20 premolars was evaluated. The defects were small (0.26 mm in diameter and 0.08 mm deep), medium (0.62 mm in diameter and 0.19 mm deep) and large (1.05 mm in diameter and 0.24 mm deep), equally distributed on each root surface. Images were obtained using Classic i-CAT cone beam computed tomography with different voxel sizes: 0.12, 0.20, 0.25 and 0.30 mm. Five oral radiologists evaluated the images. Accuracy, sensitivity, specificity, positive and negative predictive values were determined. The sensitivity decreased and specificity increased as voxel size increased. Accuracy values were the highest for the smallest voxel size (0.12 mm). The results for voxel sizes 0.20 mm and 0.25 mm were similar. Positive and negative predictive values were similar in all protocols, except with 0.30 mm, in which they were the lowest. In conclusion, external root resorption was more easily diagnosed when a smaller voxel size was used.

  2. Local tomography and focal mechanisms in the south-western Alps: Comparison of methods and tectonic implications

    NASA Astrophysics Data System (ADS)

    Nicole, Béthoux; Christian, Sue; Anne, Paul; Jean, Virieux; Julien, Fréchet; François, Thouvenot; Marco, Cattaneo

    2007-03-01

    We investigate how focal solutions and hypocenter locations may depend on the ray tracing algorithm and the strategy of velocity inversion. Using arrival times from a temporary seismological network in the south-western Alps, a local earthquake tomography has been performed by Paul et al. [Paul, A., Cattaneo, M., Thouvenot, F., Spallarossa, D., Béthoux, N., and Fréchet, J., 2001. A three-dimensional crustal velocity model of the south-western Alps from local earthquake tomography. J. Geophys. Res. 106, 19367-19390.] with the method developed by Thurber [Thurber, C.H., 1993. Local earthquake tomography: velocity and Vp/Vs-Theory, in Seismic Tomography: Theory and practice, Iyer, H.M., and Irahara eds., Chapman and Hall, New York, 563-583.]. Another inversion of the same data set is performed here using a different tomography code relying on a shooting paraxial method and cubic interpolation of velocities. The resulting images display the same main features, although Thurber's code appears to be more robust in regions with scarce ray coverage and strong velocity contrasts. Concerning hypocenter location in Piemont units, one major result is the concentration of hypocenters at the boundary between the mantle wedge of the Ivrea body and the European crust. Forty-six focal mechanisms are shown that were computed using both the take-off angles in the minimum 1-D model and in the 3-D velocity structures resulting from the two inversions. The sets of focal solutions are very similar, proving the reliability and the coherency of the focal solutions. The widespread extension in the core of the western Alps is confirmed whereas a few compressive solutions are found east of the Piemont units. These results constrain the sharp change of stress tensor and evidence a decoupling of strain beneath the east of Dora Maira massif up to beneath the north of Argentera massif. On a geodynamical point of view seismicity and focal mechanism distribution are compatible with the present

  3. Terahertz Computed Tomography of NASA Thermal Protection System Materials

    NASA Technical Reports Server (NTRS)

    Roth, D. J.; Reyes-Rodriguez, S.; Zimdars, D. A.; Rauser, R. W.; Ussery, W. W.

    2011-01-01

    A terahertz axial computed tomography system has been developed that uses time domain measurements in order to form cross-sectional image slices and three-dimensional volume renderings of terahertz-transparent materials. The system can inspect samples as large as 0.0283 cubic meters (1 cubic foot) with no safety concerns as for x-ray computed tomography. In this study, the system is evaluated for its ability to detect and characterize flat bottom holes, drilled holes, and embedded voids in foam materials utilized as thermal protection on the external fuel tanks for the Space Shuttle. X-ray micro-computed tomography was also performed on the samples to compare against the terahertz computed tomography results and better define embedded voids. Limits of detectability based on depth and size for the samples used in this study are loosely defined. Image sharpness and morphology characterization ability for terahertz computed tomography are qualitatively described.

  4. Microcomputer-Assisted Biomass Determination of Plankton Bacteria on Scanning Electron Micrographs

    PubMed Central

    Krambeck, Christiane; Krambeck, Hans-Jürgen; Overbeck, Jürgen

    1981-01-01

    Although biovolume is a better measure of biomass than is cell number, biovolumes have rarely been measured because their evaluation is extremely time-consuming. We developed a microcomputer system that assists cell size measurements on images of filtered plankton: scanning electron micrograph negatives were projected on a digitizer field, bacterial length and width were marked by a cursor, and coordinates were directly transferred to an MOS 6502 microcomputer (KIM 1). The dialogue program BABI organized and controlled the digitizer measurements in cooperation with the user, enabled corrections, and printed out results with 95% confidence limits and sample description. The time for scanning electron micrograph preparation was reduced to 15 min (quick transfer to Freon 113 during filtration and air drying). Altogether, this biovolume determination took about 2.5 h for confidence limits of ±15%. Examples are given for applications of the method: (i) comparison of 10 lakes (with specific activities for glucose uptake and for heterotrophic CO2 fixation); (ii) ranges of biomass parameters in one lake; (iii) diurnal cycles (with synchronizing effects, uptake of algal exudates, and calculation of daily growth). This method is discussed in relation to other biomass methods (epifluorescent microscopy, lipopolysaccharide technique, frequency of dividing cells) and the problem of biovolume-to-carbon conversions. Images PMID:16345807

  5. In-vivo imaging of murine tumors using complete-angle projection fluorescence molecular tomography

    NASA Astrophysics Data System (ADS)

    Deliolanis, Nikolaos C.; Dunham, Joshua; Wurdinger, Thomas; Figueiredo, Jose-Luiz; Bakhos, Tannous; Ntziachristos, Vasilis

    2009-05-01

    We interrogate the ability of free-space fluorescence tomography to image small animals in vivo using charge-coupled device (CCD) camera measurements over 360-deg noncontact projections. We demonstrate the performance of normalized dual-wavelength measurements that are essential for in-vivo use, as they account for the heterogeneous distribution of photons in tissue. In-vivo imaging is then showcased on mouse lung and brain tumors cross-validated by x-ray microcomputed tomography and histology.

  6. Micro radiography and tomography for high resolution NDT of advanced materials and microstructural components

    NASA Astrophysics Data System (ADS)

    Maisl, M.; Reiter, H.; Hoeller, P.

    The application of microradiography and microcomputed tomography for the NDT of high strength ceramics and fiber-reinforced composites is discussed. Radiography with microfocal X-ray tubes provides high-resolution radiographs using the direct projection technique. Tomography produces high-contrast images of sections of an object, and results are presented using a tomographic unit with a resolution of the order of magnitude of 20 microns.

  7. Comparison of the pulsed photoacoustic technique and the optical coherence tomography from the viewpoint of biomedical sensing

    NASA Astrophysics Data System (ADS)

    Kinnunen, Matti; Zhao, Zuomin; Myllyla, Risto

    2005-08-01

    Laser photoacoustics (PA) and optical coherence tomography (OCT) are versatile and sensitive techniques for biomedical diagnostics, imaging, and measurements. In this paper, the hdamentals of PA and OCT are considered and the applications in biomedicine reviewed. The properties of the two techniques are compared to find the proper technique for a specific application. The problems and restrictions, dependent on the factors of the human body, which have to be reduced before the clinical utilization of the techniques, are pointed out. The PA technique is more suitable for measuring or imaging the objects located in deep tissue or organs and for sensing the physiological changes caused by compositions with larger absorption variation, such as hemoglobin, blood oxygenation, and melanin. OCT is more suitable for imaging tissue surface and subsurface structures and fine structures and for sensing the physiological changes caused by compositions with larger scattering and refractive index variation, such as skin water, tissue glucose, and sweat.

  8. Direct Numerical Simulation of Liquid Nozzle Spray with Comparison to Shadowgraphy and X-Ray Computed Tomography Experimental Results

    NASA Astrophysics Data System (ADS)

    van Poppel, Bret; Owkes, Mark; Nelson, Thomas; Lee, Zachary; Sowell, Tyler; Benson, Michael; Vasquez Guzman, Pablo; Fahrig, Rebecca; Eaton, John; Kurman, Matthew; Kweon, Chol-Bum; Bravo, Luis

    2014-11-01

    In this work, we present high-fidelity Computational Fluid Dynamics (CFD) results of liquid fuel injection from a pressure-swirl atomizer and compare the simulations to experimental results obtained using both shadowgraphy and phase-averaged X-ray computed tomography (CT) scans. The CFD and experimental results focus on the dense near-nozzle region to identify the dominant mechanisms of breakup during primary atomization. Simulations are performed using the NGA code of Desjardins et al (JCP 227 (2008)) and employ the volume of fluid (VOF) method proposed by Owkes and Desjardins (JCP 270 (2013)), a second order accurate, un-split, conservative, three-dimensional VOF scheme providing second order density fluxes and capable of robust and accurate high density ratio simulations. Qualitative features and quantitative statistics are assessed and compared for the simulation and experimental results, including the onset of atomization, spray cone angle, and drop size and distribution.

  9. Effect of tomography resolution on the calculated microscopic properties of porous materials: Comparison of sandstone and carbonate rocks

    NASA Astrophysics Data System (ADS)

    Gooya, R.; Bruns, S.; Müter, D.; Moaddel, A.; Harti, R. P.; Stipp, S. L. S.; Sørensen, H. O.

    2016-09-01

    X-ray computed tomography is useful for providing insight into the internal structure of porous materials. Extracting reliable quantitative information is difficult because the derived properties rely heavily on data resolution, i.e., very different values emerge, depending on the relationship between size of the features in the sample and the resolution of the 3D tomograms. Here, we present a method for testing if resolution is sufficient for determining reliable petrophysical parameters, i.e., with low levels of uncertainty. We derived the physical properties of sandstone and carbonate rocks over a range of voxel dimensions by computationally reducing raw data resolution in our high resolution images. Lower resolution decreases the calculated surface area for all samples and increases the derived permeability for sandstone. The permeability vs change in resolution was not monotonic for carbonates. The differences in trends for the two rock types result from different pore sizes and pore size distributions.

  10. Comparison of the access window created by hemilaminectomy and mini-hemilaminectomy in the thoracolumbar vertebral canal using computed tomography.

    PubMed

    Huska, Jonathan L; Gaitero, Luis; Brisson, Brigitte A; Nykamp, Stephanie; Thomason, Jeff; Sears, William C

    2014-05-01

    Hemilaminectomy and mini-hemilaminectomy were performed on opposite sides of the spine at T11-T12, T13-L1, and L2-L3 in 11 canine cadavers in order to report differences in the access provided to the thoracolumbar vertebral canal. Measurements of the vertebral canal height, defect height, and dorsal and ventral remnants of the vertebral arch were obtained after computed tomography. A median of 7% to 20% of the vertebral canal height was not removed dorsally after mini-hemilaminectomy compared to 1% to 2% in hemilaminectomy. Thirteen to 25% of the vertebral canal height was left ventrally in mini-hemilaminectomy and 11% to 27% in hemilaminectomy. Potential for a restricted exposure of thoracolumbar lesions should be considered if lesions are located in the ventral 11% to 27% vertebral canal height when performing either procedure or in the dorsal 7% to 20% of the canal height when performing a mini-hemilaminectomy. PMID:24790230

  11. Comparison of accuracy of 64-slice cardiovascular computed tomography with coronary angiography in patients with suspected coronary artery disease.

    PubMed

    Fine, Jeffrey J; Hopkins, Christie B; Ruff, Nicol; Newton, F Carter

    2006-01-15

    Cardiovascular computed tomography (CVCT) with the recently released 64-slice technology increases spatial resolution and decreases acquisition times and slice thickness. We investigated the accuracy of 64-slice CVCT in relation to catheter angiography. We studied 66 sequential subjects who underwent 64-slice CVCT and catheter angiography within 30 days. Accuracy results were 94% for interpretable images, 95% for sensitivity, 96% for specificity, 97% for positive predictive value, and 92% for negative predictive value for lesions with >50% stenosis. We found 100% agreement between 64-slice CVCT and catheterization among vein graft evaluations (9 of 9). These metrics are vastly improved from the 16-slice generation and support 64-slice CVCT as a reliable diagnostic tool.

  12. Methods of predicting visceral fat in Brazilian adults and older adults: a comparison between anthropometry and computerized tomography.

    PubMed

    Roriz, Anna Karla Carneiro; de Oliveira, Carolina Cunha; Moreira, Pricilla Almeida; Eickemberg, Michaela; Medeiros, Jairza Maria Barreto; Sampaio, Lílian Ramos

    2011-03-01

    Visceral adipose tissue (VAT) is linked with the metabolic consequences of obesity, being necessary the use alternative methods of predicting this type of fat, like anthropometry. The objective of this study was assess the performance of anthropometry in predicting visceral fat measured with computerized tomography in adults and older adults. Study transversal with 197 individuals underwent computerized tomography (CT) and anthropometry. The variables analized were: visceral adipose tissue area by CT, Sagittal Abdominal Diameter (SAD), Waist Circumference (WC) and Waist-Hip Ratio (WHR). A descriptive analysis, Pearson correlation and ROC curve were carried out. We observed Correlations higher than 0.7 (p = 0.000) between the SAD, WC and the VAT area were found in adult men and older men and in adult women. WHR displayed the least correlations. The most sensitive and specific SAD cut-off points were equal for all the men (Adults: 20.2 cm/Older adults: 20.2 cm) but different for the women (Adults: 21.0 cm; sens.: 83.3; spec.: 79.1/Older adults: 19.9 cm; sens.: 81.0; spec.:79.3). The WC cutoff points that identified a VAT area = 130 cm2 were 90.2 cm and 92.2 cm for men (adult men--sens.: 86.7; spec.: 86.1--and older men-sens.: 79.3; spec.: 77.8 -respectively), while for women the recorded values were 92.3 cm (adult women--sens.: 83.3; spec: 81.4) and 88.2 cm (older women--sens.:76.2; spec.: 69.0). This study showed that WC and SAD achieved the best performance in the identification of visceral fat considered at risk for the development of cardiometabolic diseases in adults and older adults.

  13. Microcomputers in Vocational Home Economics Classrooms in USD #512.

    ERIC Educational Resources Information Center

    Shawnee Mission Public Schools, KS.

    A project was conducted to identify software suitable for use in home economics classes and to train home economics teachers to use that software with an Apple II Plus microcomputer. During the project, home economics software was identified, evaluated, and catalogued. Teaching strategies were adapted to include using the computer in the…

  14. Software Development Group. Software Review Center. Microcomputing Working Paper Series.

    ERIC Educational Resources Information Center

    Perkey, Nadine; Smith, Shirley C.

    Two papers describe the roles of the Software Development Group (SDG) and the Software Review Center (SRC) at Drexel University. The first paper covers the primary role of the SDG, which is designed to assist Drexel faculty with the technical design and programming of courseware for the Apple Macintosh microcomputer; the relationship of the SDG…

  15. A Bibliography of Microcomputer Software for Working Draft.

    ERIC Educational Resources Information Center

    Hodges, James O.

    Over 160 microcomputer software programs for elementary and secondary school social studies programs are included in this annotated bibliography. Listed in alphabetical order by the name of the program, the annotation contains a description of the program, appropriate grade level, the name of the system and whether it is available on disk or…

  16. Microcomputers and the Library: A Planning Guide for Managers.

    ERIC Educational Resources Information Center

    Walton, Robert A.

    This manual was designed to provide the library manager or supervisor with a basic understanding of microcomputer hardware, software, procurement, and supervision. While developed for a summer workshop series, it can also serve as an introductory text. Separate chapters cover 10 major topics: (1) the microtechnology revolution; (2) how a…

  17. TI 99/4A Microcomputers As Science Laboratory Instruments.

    ERIC Educational Resources Information Center

    Thomas, Frederick J.

    1983-01-01

    Emphasis on interfacing -- the various processes for passing information into or out of computers -- is suggested. Why the Texas Instruments microcomputer is plausible for this is noted, followed by specific interfacing suggestions, including programs for a timer and the assembly language subroutine. (MNS)

  18. Instructional Microcomputer Applications by Business Teachers in Minnesota.

    ERIC Educational Resources Information Center

    Lambrecht, Judith J.

    Data were collected from Minnesota secondary and postsecondary business teachers regarding their instructional microcomputer applications and their attitudes about several instructional computing issues. Usable surveys were returned by 342 teachers in 236 schools. The predominant brand of computer at the secondary level was the Apple II; most…

  19. Impact of the Microcomputer on the Physical Environment for Learning.

    ERIC Educational Resources Information Center

    Parker, James A.

    This paper provides an exploration of the impact of the increasing use of microcomputers in education upon curriculum development and the physical space needs in the learning environment. A secondary topic is the present and future directions of schools in the design of computer environments. (Author/MD)

  20. Planning for the Administrative Microcomputer Local Area Network.

    ERIC Educational Resources Information Center

    Rohr, Theodore; Devoti, Bart

    An overview is provided of the methods used by the Forest Park campus of St. Louis Community College (SLCC) to plan and develop a local area network (LAN) for administrative microcomputers. The first three sections provide brief descriptions of the SLCC District, SLCC, and the Forest Park campus. Section IV looks at the organization of…

  1. The Computer Connection: Four Approaches to Microcomputer Laboratory Interfacing.

    ERIC Educational Resources Information Center

    Graef, Jean L.

    1983-01-01

    Four ways in which microcomputers can be turned into laboratory instruments are discussed. These include adding an analog/digital (A/D) converter on a printed circuit board, adding an external A/D converter using the computer's serial port, attaching transducers to the game paddle ports, or connecting an instrument to the computer. (JN)

  2. A Microcomputer Exercise on Genetic Transcription and Translation.

    ERIC Educational Resources Information Center

    Meisenheimer, John L.

    1985-01-01

    Describes a microcomputer program (written for the Apple II+) which can serve as a lecture demonstration aid in explaining genetic transcription and translation. The program provides unemotional information on student errors, thus serving as a review drill to supplement the classroom. Student participation and instructor options are discussed. (DH)

  3. Using a Microcomputer in the Classroom. Third Edition.

    ERIC Educational Resources Information Center

    Bitter, Gary G.; And Others

    This book was written to help classroom teachers, lay persons, and school personnel understand the role of microcomputers in education. It has been especially designed for undergraduate and graduate technology-based education programs. Specific education examples and applications are provided throughout the book and exercises have been designed…

  4. An accurate demand feeder for fish, suitable for microcomputer control.

    PubMed

    Beach, M A; Baker, G E; Roberts, M G

    1986-01-01

    This paper describes an easily constructed and inexpensive demand feeder. The feeder is driven by an AC synchronous motor and gearbox and is suitable for microcomputer control. It will operate with inexpensive commercially available pelleted fish food, and will consistently deliver a single pellet for each operation of the motor. The components and materials can be purchased for approximately 23 pounds.

  5. The Use of a Microcomputer as an EKG Monitor.

    ERIC Educational Resources Information Center

    Walters, R. A.; Reynolds, R. F.

    1983-01-01

    Discusses the design and operation of a microcomputer system which obtains and displays an individual's electrocardiogram (EKG). The EKG information, in digital form, can be stored on a floppy disk and transmitted over telephone lines by use of a modem. (JN)

  6. ASCAL: A Microcomputer Program for Estimating Logistic IRT Item Parameters.

    ERIC Educational Resources Information Center

    Vale, C. David; Gialluca, Kathleen A.

    ASCAL is a microcomputer-based program for calibrating items according to the three-parameter logistic model of item response theory. It uses a modified multivariate Newton-Raphson procedure for estimating item parameters. This study evaluated this procedure using Monte Carlo Simulation Techniques. The current version of ASCAL was then compared to…

  7. Microcomputers and the Media Specialist: An Annotated Bibliography.

    ERIC Educational Resources Information Center

    Miller, Inabeth

    An overview of the literature reflecting the rapid development of interest in microcomputer use in education since 1978 is followed by an annotated bibliography which lists books, articles, and ERIC documents in nine categories. The first section includes materials of general interest--historical background, guides to using computers in the…

  8. A Microcomputer-Controlled T-60 NMR Emulator.

    ERIC Educational Resources Information Center

    Howard, Gary D.; DuBois, Thomas D.

    1986-01-01

    Discusses the problems created by the insufficient number of major data collection and analysis instruments in most college chemistry courses. Suggests the use of less expensive microcomputer-controlled instrument emulators, which resemble the actual instruments. Discusses the application of one such emulator in an instrumental analysis course.…

  9. Development of a microcomputer-based teleconference system

    SciTech Connect

    Allen, R.W.

    1980-09-12

    A computer based teleconference system was developed at the Lawrence Livermore National Laboratory (LLNL) from FY 1978 through FY 1980. The system is unique because it is based on a single low-cost microcomputer. The implementation of the system, with emphasis on the practical software issues addressed during development, is discussed.

  10. Foreign Language Teaching Programs for Microcomputers: A Volume of Reviews.

    ERIC Educational Resources Information Center

    Culley, Gerald R., Ed.; Mulford, George W., Ed.

    Teachers and supervisors of foreign language programs from 29 high schools in six states provide reviews of foreign language microcomputer courseware. Evaluations of the 25 programs for French, German, Italian, Russian and Spanish are based on: (1) quality of content; (2) relevance to subject area; (3) suitability to computer medium; (4)…

  11. Using Microcomputers in School Administration. Fastback No. 248.

    ERIC Educational Resources Information Center

    Connors, Eugene T.; Valesky, Thomas C.

    This "fastback" outlines the steps to take in computerizing school administration. After an introduction that lists the potential benefits of microcomputers in administrative offices, the booklet begins by delineating a three-step process for establishing an administrative computer system: (1) creating a district-level committee of administrators,…

  12. Microcomputers as Interfaces to Bibliographic Utilities (OCLC, RLIN, etc.).

    ERIC Educational Resources Information Center

    Genaway, David C.

    1983-01-01

    Discusses microcomputer interfacing systems which accept full MARC record from bibliographic utility, reformat and transform it into local library computer system format; illustrates how the TPS-400 interface works; outlines criteria for interface selection; indicates installation decisions; and notes limitation problems and benefits. Four…

  13. Microcomputers in Scottish Schools--A National Plan.

    ERIC Educational Resources Information Center

    Paton, George

    1985-01-01

    Describes the general elements of the National Plan for Microcomputers in Scottish schools, a plan devised by the Scottish Microelectronic Development Programme, which stresses national standardization of computer systems for compatibility of software and communication links and development of national software application packages. (MBR)

  14. Integrating Microcomputers and Microelectronics into the Physics Curriculum.

    ERIC Educational Resources Information Center

    Gale, Douglas S.

    1980-01-01

    Describes an interdisciplinary microcomputer and microelectronics program offered jointly by the Physics and Computer Science Departments of East Texas State University. The program operates on both the graduate and undergraduate level. Content as well as structure of the program are discussed. (Author/DS)

  15. Microcomputer Network for Computerized Adaptive Testing (CAT): Program Listing.

    ERIC Educational Resources Information Center

    Quan, Baldwin; And Others

    This program listing is a supplement to the Microcomputer Network for Computerized Adaptive Testing (CAT). The driver textfile program allows access to major subprograms of the CAT project. The test administration textfile program gives examinees a prescribed set of subtests. The parameter management textfile program establishes a file containing…

  16. Library Software: Directory of Microcomputer Software for Libraries.

    ERIC Educational Resources Information Center

    Walton, Robert A.

    The availability of appropriate software for library applications is a continuing problem, and this directory is designed to reduce the frustration of librarians in their search for library software for a microcomputer by providing profiles of software packages designed specifically for libraries. Each profile describes the purpose of the program,…

  17. Ideas for Integrating the Microcomputer with Special Education.

    ERIC Educational Resources Information Center

    Pollard, Jim, Ed.

    This publication contains six presentations on using microcomputers in special education, submitted by special education teachers at informal information sharing sessions. The first is a lesson plan involving pre-computer activities that prepare preschool developmentally delayed children for using a computer keyboard. Finger isolation and…

  18. Matrix algebra routines for the Acorn Archimedes microcomputer: example applications.

    PubMed

    Fielding, A

    1988-08-01

    A set of matrix algebra routines have been written, as BASICV procedures, for the Acorn Archimedes microcomputer. It is shown that these procedures are executed so quickly that programs, which require matrix algebra computations, can be written in interpreted BASIC. Two example applications, reciprocal averaging and principal components analysis, are demonstrated.

  19. Model Experiment of Two-Dimentional Brownian Motion by Microcomputer.

    ERIC Educational Resources Information Center

    Mishima, Nobuhiko; And Others

    1980-01-01

    Describes the use of a microcomputer in studying a model experiment (Brownian particles colliding with thermal particles). A flow chart and program for the experiment are provided. Suggests that this experiment may foster a deepened understanding through mutual dialog between the student and computer. (SK)

  20. Ideas for Integrating the Microcomputer into Science Instruction.

    ERIC Educational Resources Information Center

    Pollard, Jim, Ed.

    Much of the innovation in the use of microcomputers in education has come from classroom teachers who are using computers with students. In October, 1987, forums were held for secondary school science teachers who were using computers in their science classes. Within this document are some of the lesson plans that the participating teachers…

  1. Technology and Microcomputers for an Information Centre/Special Library.

    ERIC Educational Resources Information Center

    Daehn, Ralph M.

    1984-01-01

    Discusses use of microcomputer hardware and software, telecommunications methods, and advanced library methods to create a specialized information center's database of literature relating to farm machinery and food processing. Systems and services (electronic messaging, serials control, database creation, cataloging, collections, circulation,…

  2. An Observational Study of Social Processes in Microcomputer Classrooms.

    ERIC Educational Resources Information Center

    Feldmann, Shirley C.; And Others

    This observational study examined student and teacher verbal and nonverbal behaviors in microcomputer classrooms in a high school where most of the students are Black, Hispanic, or Asian, and almost half of them are classified as economically disadvantaged. A total of 125 students in grades 9 to 12 were observed, with 47 students in marketing, 18…

  3. Microcomputers & Educational Researchers: Writing, Project Management, Statistics Software, & Data Retrieval.

    ERIC Educational Resources Information Center

    Knirk, Frederick G.

    Designed to assist educational researchers in utilizing microcomputers, this paper presents information on four types of computer software: writing tools for educators, statistical software designed to perform analyses of small and moderately large data sets, project management tools, and general education/research oriented information services…

  4. Teaching Economics: Research Findings from a Microcomputer/Videodisc Project.

    ERIC Educational Resources Information Center

    Glenn, Allen D.; And Others

    1984-01-01

    Describes field test findings of a project funded by the Minnesota Educational Computing Consortium and the Rockefeller Family Fund to demonstrate that microcomputers and home videodisc players can deliver instruction to students. Basic research questions and field testing procedures for a high school economics course are provided. (MBR)

  5. Validity of the Microcomputer Evaluation Screening and Assessment Aptitude Scores.

    ERIC Educational Resources Information Center

    Janikowski, Timothy P.; And Others

    1991-01-01

    Examined validity of Microcomputer Evaluation Screening and Assessment (MESA) aptitude scores relative to General Aptitude Test Battery (GATB) using multitrait-multimethod correlational analyses. Findings from 54 rehabilitation clients and 29 displaced workers revealed no evidence to support the construct validity of the MESA. (Author/NB)

  6. Client Perceptions of the Microcomputer Evaluation and Screening Assessment.

    ERIC Educational Resources Information Center

    Bordieri, James E.; Musgrave, Jack

    1989-01-01

    Explored rehabilitation clients' (N=75) perceptions of Microcomputer Evaluation and Screening Assessment (MESA). Results showed clients experienced greater enjoyment, but more difficulty, learning how to complete computer exercises than hardware exercises but viewed computer exercises instructions as easier to understand. Observed differences in…

  7. Utilization of the Microcomputer in the Mathematics Classroom.

    ERIC Educational Resources Information Center

    Pruett, Poppy L.; And Others

    1993-01-01

    Reports a study investigating the instructional use of microcomputers by secondary mathematics teachers, and discusses results from a sample of 128 completed questionnaires showing that computer utilization is hampered by inadequate access to equipment, lack of software appropriate to the mathematics curricula, and a lack of guidance for…

  8. Microcomputer Usage in Secondary Marketing Education. A National Study.

    ERIC Educational Resources Information Center

    Searle, A. Gary

    A study was conducted to determine microcomputer hardware, software, and inservice components of secondary marketing education programs. A questionnaire was developed and sent to 420 teacher-coordinators in 42 states. A total of 225 (54 percent) usable returns were tabulated at the University of Wisconsin-Stout Computer Center. Results of the…

  9. Evaluation of Three Microcomputer Teaching Modules. SUMIT Courseware Development Project.

    ERIC Educational Resources Information Center

    Soldan, Ted

    The purpose of this series of experiments was to examine two questions related to the effectiveness of computer assisted instruction (CAI). Can microcomputer modules teach effectively, and do they enhance learning when used as a supplement to traditional teaching methods? Part 1 of this report addresses the former question and part 2 addresses the…

  10. A Microcomputer-Based Interactive Presentation Development System.

    ERIC Educational Resources Information Center

    Moreau, Dennis R.; Dominick, Wayne D.

    1988-01-01

    Reviews research and development projects sponsored by the National Aeronautics and Space Administration (NASA) that address microcomputer-based support for instructional activities at the University of Southwestern Louisiana. Highlights include a graphics project, local area networks, and the Interactive Presentation Development System, which is…

  11. Microcomputer Simulation of Nonlinear Systems: From Oscillations to Chaos.

    ERIC Educational Resources Information Center

    Raw, Cecil J. G.; Stacey, Larry M.

    1989-01-01

    Presents two short microcomputer programs which illustrate features of nonlinear dynamics, including steady states, periodic oscillations, period doubling, and chaos. Logistic maps are explained, inclusion in undergraduate chemistry and physics courses to teach nonlinear equations is discussed, and applications in social and biological sciences…

  12. Planning the Use of Microcomputers in Higher Education Administration.

    ERIC Educational Resources Information Center

    Slovacek, Simeon P.; Dolence, Michael G.

    The process of planning the role of the microcomputer in higher education administration is investigated through a survey of a sample of universities and colleges in California engaged in such efforts, and through a review of literature in education as well as computing. A major objective of the study was to systematically investigate the…

  13. Executive Decision Making: Using Microcomputers in Budget Planning.

    ERIC Educational Resources Information Center

    Hoffman, Roslyn; Robinson, Lucinda

    The successful integration of microcomputer support to help prepare for an anticipated budget crisis at the University of Illinois at Chicago is described. The IBM Personal Computer and VisiCalc software were key tools in the decision support system. When campus executives were instructed to cut budgets and reallocate funds to produce a "Doomsday…

  14. Microcomputer Activities Which Encourage the Reading-Writing Connection.

    ERIC Educational Resources Information Center

    Balajthy, Ernest

    Many reading teachers, cognizant of the creative opportunities for skill development allowed by new reading-writing software, are choosing to use microcomputers in their classrooms full-time. Adventure story creation programs capitalize on reading-writing integration by allowing children, with appropriate assistance, to create their own…

  15. Logo Burn-In. Microcomputing Working Paper Series.

    ERIC Educational Resources Information Center

    Drexel Univ., Philadelphia, PA. Microcomputing Program.

    This paper describes a hot-stamping operation undertaken at Drexel University in an attempt to prevent computer theft on campus. The program was initiated in response to the University's anticipated receipt of up to 3,000 Macintosh microcomputers per year and the consequent publicity the university was receiving. All clusters of computers (e.g.,…

  16. Microcomputer-Based Digital Signal Processing Laboratory Experiments.

    ERIC Educational Resources Information Center

    Tinari, Jr., Rocco; Rao, S. Sathyanarayan

    1985-01-01

    Describes a system (Apple II microcomputer interfaced to flexible, custom-designed digital hardware) which can provide: (1) Fast Fourier Transform (FFT) computation on real-time data with a video display of spectrum; (2) frequency synthesis experiments using the inverse FFT; and (3) real-time digital filtering experiments. (JN)

  17. The Microcomputer as an Aid in Teaching Dynamic Systems Analysis.

    ERIC Educational Resources Information Center

    Young, Peter

    1985-01-01

    Describes the major aspects of a 20-lecture introductory course for environmental science students, showing how microcomputers can help teach dynamic systems concepts. Also discusses the continuous stirred tank reactor as a simple dynamic system, higher order systems, frequency response, nonlinear systems, and feedback control. (JN)

  18. Development of an In-Plant Microcomputer Literacy Lab.

    ERIC Educational Resources Information Center

    Gacka, Richard C.

    General Electric Company (GE) of Erie, Pennsylvania, hosts onsite literacy classes in conjunction with the Northwest Tri-County Unit. The development of the inplant microcomputer literacy lab expands the offerings available to the participating adult basic education and General Educational Development program students by supplying software and…

  19. Evaluating Microcomputer Courses in a Non-Traditional Setting.

    ERIC Educational Resources Information Center

    Thompson, Gary E.

    Summer Tech '84 was the product of a joint venture of the College of Education of Ohio State University and the Columbus Ohio Public Schools to provide instruction on the use of microcomputers to citizens of the Columbus metropolitan area. For four weeks, 80 different 10-hour classes were offered in eight areas: introductory computer literacy,…

  20. A BASIC Microcomputer Program for Estimating Test Reliability.

    ERIC Educational Resources Information Center

    Cobern, William W.

    This computer program, written in BASIC, performs three different calculations of test reliability: (1) the Kuder-Richardson method; (2); the "common split-half" method; and (3) the Rulon-Guttman split-half method. The program reads sequential access data files for microcomputers that have been set up by statistical packages such as STATPAC. The…