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Sample records for three-dimensional isotropic mri

  1. Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study

    Energy Technology Data Exchange (ETDEWEB)

    Olszewski, Raphael; Reychler, H. [Universite Catholique de Louvain, Department of Oral and Maxillofacial Surgery, Cliniques Universitaires Saint Luc, Brussels (Belgium); Liu, Y.; Xu, T.M. [Peking University School and Hospital of Stomatology, Department of Orthodontics, Beijing (China); Duprez, T. [Universite Catholique de Louvain, Department of Radiology, Cliniques Universitaires Saint Luc, Brussels (Belgium)

    2009-06-15

    Our knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion. Three-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2. We were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi. 3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field. (orig.)

  2. Three-dimensional appearance of the lips muscles with three-dimensional isotropic MRI: in vivo study.

    Science.gov (United States)

    Olszewski, Raphael; Liu, Y; Duprez, T; Xu, T M; Reychler, H

    2009-06-01

    Our knowledge of facial muscles is based primarily on atlases and cadaveric studies. This study describes a non-invasive in vivo method (3D MRI) for segmenting and reconstructing facial muscles in a three-dimensional fashion. Three-dimensional (3D), T1-weighted, 3 Tesla, isotropic MRI was applied to a subject. One observer performed semi-automatic segmentation using the Editor module from the 3D Slicer software (Harvard Medical School, Boston, MA, USA), version 3.2. We were able to successfully outline and three-dimensionally reconstruct the following facial muscles: pars labialis orbicularis oris, m. levatro labii superioris alaeque nasi, m. levator labii superioris, m. zygomaticus major and minor, m. depressor anguli oris, m. depressor labii inferioris, m. mentalis, m. buccinator, and m. orbicularis oculi. 3D reconstruction of the lip muscles should be taken into consideration in order to improve the accuracy and individualization of existing 3D facial soft tissue models. More studies are needed to further develop efficient methods for segmentation in this field.

  3. Intracranial arterial wall imaging using three-dimensional high isotropic resolution black blood MRI at 3.0 Tesla.

    Science.gov (United States)

    Qiao, Ye; Steinman, David A; Qin, Qin; Etesami, Maryam; Schär, Michael; Astor, Brad C; Wasserman, Bruce A

    2011-07-01

    To develop a high isotropic-resolution sequence to evaluate intracranial vessels at 3.0 Tesla (T). Thirteen healthy volunteers and 4 patients with intracranial stenosis were imaged at 3.0T using 0.5-mm isotropic-resolution three-dimensional (3D) Volumetric ISotropic TSE Acquisition (VISTA; TSE, turbo spin echo), with conventional 2D-TSE for comparison. VISTA was repeated for 6 volunteers and 4 patients at 0.4-mm isotropic-resolution to explore the trade-off between SNR and voxel volume. Wall signal-to-noise-ratio (SNR(wall) ), wall-lumen contrast-to-noise-ratio (CNR(wall-lumen) ), lumen area (LA), wall area (WA), mean wall thickness (MWT), and maximum wall thickness (maxWT) were compared between 3D-VISTA and 2D-TSE sequences, as well as 3D images acquired at both resolutions. Reliability was assessed by intraclass correlations (ICC). Compared with 2D-TSE measurements, 3D-VISTA provided 58% and 74% improvement in SNR(wall) and CNR(wall-lumen) , respectively. LA, WA, MWT and maxWT from 3D and 2D techniques highly correlated (ICCs of 0.96, 0.95, 0.96, and 0.91, respectively). CNR(wall-lumen) using 0.4-mm resolution VISTA decreased by 27%, compared with 0.5-mm VISTA but with reduced partial-volume-based overestimation of wall thickness. Reliability for 3D measurements was good to excellent. The 3D-VISTA provides SNR-efficient, highly reliable measurements of intracranial vessels at high isotropic-resolution, enabling broad coverage in a clinically acceptable time. Copyright © 2011 Wiley-Liss, Inc.

  4. Three-dimensional isotropic T2-weighted cervical MRI at 3 T: Comparison with two-dimensional T2-weighted sequences

    International Nuclear Information System (INIS)

    Kwon, J.W.; Yoon, Y.C.; Choi, S.-H.

    2012-01-01

    Aim: To compare three-dimensional (3D) isotropic T2-weighted magnetic resonance imaging (MRI) sequences and reformation with two-dimensional (2D) T2-weighted sequences regarding image quality of the cervical spine at 3 T. Materials and methods: A phantom study was performed using a water-filled cylinder. The signal-to-noise and image homogeneity were evaluated. Fourteen (n = 14) volunteers were examined at 3 T using 3D isotropic T2-weighted sagittal and conventional 2D T2-weighted sagittal, axial, and oblique sagittal MRI. Multiplanar reformation (MPR) of the 3D T2-weighted sagittal dataset was performed simultaneously with image evaluation. In addition to artefact assessment, the visibility of anatomical structures in the 3D and 2D sequences was qualitatively assessed by two radiologists independently. Cohen’s kappa and Wilcoxon signed rank test were used for the statistical analysis. Result: The 3D isotropic T2-weighted sequence resulted in the highest signal-to-noise ratio (SNR) and lowest non-uniformity (NU) among the sequences in the phantom study. Quantitative evaluation revealed lower NU values of the cerebrospinal fluid (CSF) and muscles in 2D T2-weighted sagittal sequences compared to the 3D volume isotropic turbo spin-echo acquisition (VISTA) sequence. The other NU values revealed no statistically significant difference between the 2D turbo spin-echo (TSE) and 3D VISTA sequences (0.059 < p < 0.959). 3D VISTA images showed significantly fewer CSF flow artefacts (p < 0.001) and better delineated intradural nerve rootlets (p = 0.001) and neural foramina (p = 0.016) compared to 2D sequences. Conclusion: A 3D T2 weighted sequence is superior to conventional 2D sequences for the delineation of intradural nerve rootlets and neural foramina and is less affected by CSF flow artefacts.

  5. Full three-dimensional isotropic transformation media

    International Nuclear Information System (INIS)

    García-Meca, C; Martí, J; Martínez, A; Ortuño, R

    2014-01-01

    We present a method that enables the implementation of full three-dimensional (3D) transformation media with minimized anisotropy. It is based on a special kind of shape-preserving mapping and a subsequent optimization process. For sufficiently smooth transformations, the resulting anisotropy can be neglected, paving the way for practically realizable 3D devices. The method is independent of the considered wave phenomenon and can thus be applied to any field for which a transformational technique exists, such as acoustics or thermodynamics. Full 3D isotropy has an additional important implication for optical transformation media, as it eliminates the need for magnetic materials in many situations. To illustrate the potential of the method, we design 3D counterparts of transformation-based electromagnetic squeezers and bends. (paper)

  6. Three-dimensional volumetric MRI with isotropic resolution: improved speed of acquisition, spatial resolution and assessment of lesion conspicuity in patients with recurrent soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Ahlawat, Shivani [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); Morris, Carol [The Johns Hopkins Medical Institutions, Department of Orthopedic Surgery, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Oncology, Baltimore, MD (United States); Fayad, Laura M. [The Johns Hopkins Medical Institutions, The Russell H. Morgan Department of Radiology and Radiological Science, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Orthopedic Surgery, Baltimore, MD (United States); The Johns Hopkins Medical Institutions, Department of Oncology, Baltimore, MD (United States)

    2016-05-15

    To assess the acquisition speed, lesion conspicuity, and inter-observer agreement associated with volumetric T{sub 1}-weighted MR sequences with isotropic resolution for detecting recurrent soft-tissue sarcoma (STS). Fifteen subjects with histologically proven recurrent STS underwent MRI, including axial and coronal T{sub 1}-weighted spin echo (T{sub 1}-WSE) (5-mm slice thickness) and coronal 3D volumetric T{sub 1}-weighted (fat-suppressed, volume-interpolated, breath-hold examination; repetition time/echo time, 3.7/1.4 ms; flip angle, 9.5 ; 1-mm slice thickness) sequences before and after intravenous contrast administration. Subtraction imaging and multiplanar reformations (MPRs) were performed. Acquisition times for T{sub 1}-WSE in two planes and 3D sequences were reported. Two radiologists reviewed images for quality (>50 % artifacts, 25-50 % artifacts, <25 % artifacts, and no substantial artifacts), lesion conspicuity, contrast-to-noise ratio (CNR{sub muscle}), recurrence size, and recurrence-to-joint distance. Descriptive and intraclass correlation (ICC) statistics are given. Mean acquisition times were significantly less for 3D imaging compared with 2-plane T{sub 1}-WSE (183.6 vs 342.6 s; P = 0.012). Image quality was rated as having no substantial artifacts in 13/15 and <25 % artifacts in 2/15. Lesion conspicuity was significantly improved for subtracted versus unsubtracted images (CNR{sub muscle}, 100 ± 138 vs 181 ± 199; P = 0.05). Mean recurrent lesion size was 2.5 cm (range, 0.7-5.7 cm), and measurements on 3D sequences offered excellent interobserver agreement (ICC, 0.98 for lesion size and 0.96 for recurrence-to-joint distance with MPR views). Three-dimensional volumetric sequences offer faster acquisition times, higher spatial resolution, and MPR capability compared with 2D T{sub 1}-WSE for postcontrast imaging. Subtraction imaging provides higher lesion conspicuity for detecting recurrent STS in skeletal muscle, with excellent interobserver

  7. Three-dimensional magnetospheric equilibrium with isotropic pressure

    International Nuclear Information System (INIS)

    Cheng, C.Z.

    1995-05-01

    In the absence of the toroidal flux, two coupled quasi two-dimensional elliptic equilibrium equations have been derived to describe self-consistent three-dimensional static magnetospheric equilibria with isotropic pressure in an optimal (Ψ,α,χ) flux coordinate system, where Ψ is the magnetic flux function, χ is a generalized poloidal angle, α is the toroidal angle, α = φ - δ(Ψ,φ,χ) is the toroidal angle, δ(Ψ,φ,χ) is periodic in φ, and the magnetic field is represented as rvec B = ∇Ψ x ∇α. A three-dimensional magnetospheric equilibrium code, the MAG-3D code, has been developed by employing an iterative metric method. The main difference between the three-dimensional and the two-dimensional axisymmetric solutions is that the field-aligned current and the toroidal magnetic field are finite for the three-dimensional case, but vanish for the two-dimensional axisymmetric case. With the same boundary flux surface shape, the two-dimensional axisymmetric results are similar to the three-dimensional magnetosphere at each local time cross section

  8. Intra-connected three-dimensionally isotropic bulk negative index photonic metamaterial

    International Nuclear Information System (INIS)

    Guney, Durdu; Koschny, Thomas; Soukoulis, Costas

    2010-01-01

    Isotropic negative index metamaterials (NIMs) are highly desired, particularly for the realization of ultra-high resolution lenses. However, existing isotropic NIMs function only two-dimensionally and cannot be miniaturized beyond microwaves. Direct laser writing processes can be a paradigm shift toward the fabrication of three-dimensionally (3D) isotropic bulk optical metamaterials, but only at the expense of an additional design constraint, namely connectivity. Here, we demonstrate with a proof-of-principle design that the requirement connectivity does not preclude fully isotropic left-handed behavior. This is an important step towards the realization of bulk 3D isotropic NIMs at optical wavelengths.

  9. Full three-dimensional isotropic carpet cloak designed by quasi-conformal transformation optics.

    Science.gov (United States)

    Silva, Daniely G; Teixeira, Poliane A; Gabrielli, Lucas H; Junqueira, Mateus A F C; Spadoti, Danilo H

    2017-09-18

    A fully three-dimensional carpet cloak presenting invisibility in all viewing angles is theoretically demonstrated. The design is developed using transformation optics and three-dimensional quasi-conformal mapping. Parametrization strategy and numerical optimization of the coordinate transformation deploying a quasi-Newton method is applied. A discussion about the minimum achievable anisotropy in the 3D transformation optics is presented. The method allows to reduce the anisotropy in the cloak and an isotropic medium could be considered. Numerical simulations confirm the strategy employed enabling the design of an isotropic reflectionless broadband carpet cloak independently of the incident light direction and polarization.

  10. Comparison of two-dimensional fast spin echo T2 weighted sequences and three-dimensional volume isotropic T2 weighted fast spin echo (VISTA) MRI in the evaluation of triangular fibrocartilage of the wrist.

    Science.gov (United States)

    Park, Hee Jin; Lee, So Yeon; Kang, Kyung A; Kim, Eun Young; Shin, Hun Kyu; Park, Se Jin; Park, Jai Hyung; Kim, Eugene

    2018-04-01

    To compare image quality of three-dimensional volume isotropic T 2 weighted fast spin echo (3D VISTA) and two-dimensional (2D) T 2 weighted images (T2WI) for evaluation of triangular fibrocartilage (TFC) and to investigate whether 3D VISTA can replace 2D T 2 WI in evaluating TFC injury. This retrospective study included 69 patients who received wrist MRIs using both 2D T 2 WI and 3D VISTA techniques for assessment of wrist pathology, including TFC injury. Two radiologists measured the signal-to-noise ratio (SNR) and the contrast-to-noise ratio (CNR) of the two sequences. The anatomical identification score and diagnostic performance were independently assessed by two interpreters. The diagnostic abilities of 3D VISTA and 2D T 2 WI were analysed by sensitivity, specificity and accuracy for diagnosing TFC injury using surgically or clinically confirmed diagnostic reference standards. 17 cases (25%) were classified as having TFC injury. 2 cases (12%) were diagnosed surgically, and 15 cases (88%) were diagnosed by physical examination. 52 cases (75%) were diagnosed as having intact TFC. 8 of these cases (15%) were surgically confirmed, while the others were diagnosed by physical examination and clinical findings. The 3D VISTA images had significantly higher SNR and CNR values for the TFC than 2D T 2 WI images. The scores of 3D VISTA's total length, full width and sharpness were similar to those of 2D T 2 WI. We were unable to find a significant difference between 3D VISTA and 2D T 2 WI in the ability to diagnose TFC injury. 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment. Advances in knowledge: 3D VISTA image quality is similar to that of 2D T 2 WI for TFC evaluation and is also excellent for tissue contrast. 3D VISTA can replace 2D images in TFC injury assessment.

  11. Three-dimensional isotropic fat-suppressed proton density-weighted MRI at 3 tesla using a T/R-coil can replace multiple plane two-dimensional sequences in knee imaging

    Energy Technology Data Exchange (ETDEWEB)

    Homsi, R.; Luetkens, J.A. [Bonn Univ. (Germany). Dept. of Radiology; Gieseke, J. [Philips Healthcare, Hamburg (Germany); and others

    2016-10-15

    To evaluate whether a 3D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS. 52 patients (26 men, mean age: 41.9±14.5 years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40-0.63 x 0.44-0.89 x 3 mm{sup 3}) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63 x 0.68 x 0.63 mm{sup 3}). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13 patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection. The CR was higher in the ACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (p<0.01 for ACL and PCL; p=0.07 for MEN). Compared to 2D images, the OIQ was rated higher in 3D-PDwFS images (p<0.01) due to fewer artifacts and HFS despite the lower IS (p<0.01). The sensitivity and specificity of lesion detection in 3D- and 2D-PDwFS were similar. Compared to standard multiplanar 2D-PDwFS knee imaging, isotropic high spatial resolution 3D-PDwFS of the knee at 3.0T can be acquired with high image quality in a reasonable scan time. Multiplanar reformations in arbitrary planes may serve as an additional benefit of 3D-PDwFS.

  12. Three-dimensional MRI of the glenoid labrum

    International Nuclear Information System (INIS)

    Loehr, S.P.; Pope, T.L. Jr.; Martin, D.F.; Link, K.M.; Monu, J.U.V.; Hunter, M.; Reboussin, D.

    1995-01-01

    The objective of this study was to assess the accuracy of three-dimensional (3D) magnetic resonance imaging (MRI) reformation in the evaluation of tears of the glenoid labrum complex (GLC). Fifty-five shoulders were evaluated by MRI using standard spin-echo sequences. Gradient-refocused-echo axial projections were used to assess the GLC on the two-dimensional (2D) studies. Three-dimensional Fourier transform multiplanar gradient-recalled imaging with a resolution of 0.7 mm was also performed in all patients. Independent analyses of the anterior and posterior labra were performed in a blinded manner for both the 2D and 3D studies by three experienced musculoskeletal radiologists. Observations of the imaging studies were compared with the videoarthroscopic findings. The appearance of the GLC was rated on a scale of 0 to 4 (0-2=normal, 3, 4=abnormal or torn). The diagnostic confidence was averaged from the three reader's scores. Anterior labral tears were effectively detected with sensitivities of 89% and 96% and specificities of 96% and 100% (P<0.0001) for the 2D and 3D studies, respectively. For posterior labral tears, the sensitivity and specificity of the 2D method were 47% and 98%, respectively. The sensitivity and specificity of the 3D volume sequence were 53% and 98%, respectively. The lower sensitivity of both imaging methods for detecting posterior labral tears may be influenced by the smaller number (n=5) of arthroscopically confirmed cases in our study and reflects the difficulty of visualizing the posteroinferior borders of the GLC with present MRI techniques. (orig.)

  13. Three-dimensional brain mapping using fMRI

    International Nuclear Information System (INIS)

    Fukunaga, Masaki; Tanaka, Chuzo; Umeda, Masahiro; Ebisu, Toshihiko; Aoki, Ichio; Higuchi, Toshihiro; Naruse, Shoji.

    1997-01-01

    Functional mapping of the activated brain, the location and extent of the activated area were determined, during motor tasks and sensory stimulation using fMRI superimposed on 3D anatomical MRI. Twelve volunteers were studied. The fMR images were acquired using a 2D gradient echo echo planar imaging sequence. The 3D anatomical MR images of the whole brain were acquired using a conventional 3D gradient echo sequence. Motor tasks were sequential opposition of fingers, clenching a hand and elbow flexion. Somatosensory stimulation were administered by scrubbing the palm and sole with a washing sponge. Visual stimulation consisted of full visual field stimulation. Data were analyzed by the cross-correlation method. Transversal fMR images and anatomical images were reconstructed using both volume-, surface-rendering methods, and reconstructed for coronal and sagittal sections. Activated areas were expressed using the three primary colors. Motor tasks activated the contralateral primary motor area (M1), the primary somatosensory area (S1) and the supplementary motor area (SMA). Somatosensory tasks activated the contralateral S1, M1 and secondary sensory area (S2). Activated areas during full visual field stimulation was observed in the bilateral occipital lobe, including both the primary cortex. Three-dimensional brain mapping allowed visualization of the anatomical location and extent of the activated brain during both motor task and sensory stimulation. Using this method we could obtain a functional map similar to the Penfield's schema. (author)

  14. Three-Dimensional Isotropic Fat-Suppressed Proton Density-Weighted MRI at 3 Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging.

    Science.gov (United States)

    Homsi, R; Gieseke, J; Luetkens, J A; Kupczyk, P; Maedler, B; Kukuk, G M; Träber, F; Agha, B; Rauch, M; Rajakaruna, N; Willinek, W; Schild, H H; Hadizadeh, D R

    2016-10-01

    To evaluate whether a 3 D proton density-weighted fat-suppressed sequence (PDwFS) of the knee is able to replace multiplanar 2D-PDwFS. 52 patients (26 men, mean age: 41.9 ± 14.5years) underwent magnetic resonance imaging (MRI) of the knee at 3.0 Tesla using a T/R-coil. The imaging protocol included 3 planes of 2D-PDwFS (acquisition time (AT): 6:40 min; voxel sizes: 0.40 - 0.63 × 0.44 - 0.89 × 3mm³) and a 3D-PDwFS (AT: 6:31 min; voxel size: 0.63 × 0.68 × 0.63mm³). Homogeneity of fat suppression (HFS), artifacts, and image sharpness (IS) were evaluated on a 5-point scale (5[excellent] - 1[non-diagnostic]). The sum served as a measure for the overall image quality (OIQ). Contrast ratios (CR) compared to popliteal muscle were calculated for the meniscus (MEN), anterior (ACL) and posterior cruciate ligaments (PCL). In 13 patients who underwent arthroscopic knee surgery, two radiologists evaluated the presence of meniscal, ligamental and cartilage lesions to estimate the sensitivity and specificity of lesion detection. The CR was higher in the ACL, PCL and MEN in 3D- PDwFS compared to 2D-PDwFS (p Tesla Using a T/R-Coil Can Replace Multiple Plane Two-Dimensional Sequences in Knee Imaging. Fortschr Röntgenstr 2016; 188: 949 - 956. © Georg Thieme Verlag KG Stuttgart · New York.

  15. Three-Dimensionally Isotropic Negative Refractive Index Materials from Block Copolymer Self-Assembled Chiral Gyroid Networks

    KAUST Repository

    Hur, Kahyun

    2011-10-17

    Metamaterials are engineered artificial materials that offer new functionalities such as super-resolution imaging and cloaking. Calculations of the photonic properties of three-dimensionally isotropic metamaterials with cubic double gyroid and alternating gyroid morphologies from block copolymer self-assembly are presented.

  16. Lattice Boltzmann model for three-dimensional decaying homogeneous isotropic turbulence

    International Nuclear Information System (INIS)

    Xu Hui; Tao Wenquan; Zhang Yan

    2009-01-01

    We implement a lattice Boltzmann method (LBM) for decaying homogeneous isotropic turbulence based on an analogous Galerkin filter and focus on the fundamental statistical isotropic property. This regularized method is constructed based on orthogonal Hermite polynomial space. For decaying homogeneous isotropic turbulence, this regularized method can simulate the isotropic property very well. Numerical studies demonstrate that the novel regularized LBM is a promising approximation of turbulent fluid flows, which paves the way for coupling various turbulent models with LBM

  17. Split energy–helicity cascades in three-dimensional homogeneous and isotropic turbulence

    NARCIS (Netherlands)

    Biferale, L.; Musacchio, S.; Toschi, F.

    2013-01-01

    We investigate the transfer properties of energy and helicity fluctuations in fully developed homogeneous and isotropic turbulence by changing the nature of the nonlinear Navier–Stokes terms. We perform a surgery of all possible interactions, by keeping only those triads that have sign-definite

  18. Isotropic three-dimensional T2 mapping of knee cartilage: Development and validation.

    Science.gov (United States)

    Colotti, Roberto; Omoumi, Patrick; Bonanno, Gabriele; Ledoux, Jean-Baptiste; van Heeswijk, Ruud B

    2018-02-01

    1) To implement a higher-resolution isotropic 3D T 2 mapping technique that uses sequential T 2 -prepared segmented gradient-recalled echo (Iso3DGRE) images for knee cartilage evaluation, and 2) to validate it both in vitro and in vivo in healthy volunteers and patients with knee osteoarthritis. The Iso3DGRE sequence with an isotropic 0.6 mm spatial resolution was developed on a clinical 3T MR scanner. Numerical simulations were performed to optimize the pulse sequence parameters. A phantom study was performed to validate the T 2 estimation accuracy. The repeatability of the sequence was assessed in healthy volunteers (n = 7). T 2 values were compared with those from a clinical standard 2D multislice multiecho (MSME) T 2 mapping sequence in knees of healthy volunteers (n = 13) and in patients with knee osteoarthritis (OA, n = 5). The numerical simulations resulted in 100 excitations per segment and an optimal radiofrequency (RF) excitation angle of 15°. The phantom study demonstrated a good correlation of the technique with the reference standard (slope 0.9 ± 0.05, intercept 0.2 ± 1.7 msec, R 2 ≥ 0.99). Repeated measurements of cartilage T 2 values in healthy volunteers showed a coefficient of variation of 5.6%. Both Iso3DGRE and MSME techniques found significantly higher cartilage T 2 values (P < 0.03) in OA patients. Iso3DGRE precision was equal to that of the MSME T 2 mapping in healthy volunteers, and significantly higher in OA (P = 0.01). This study successfully demonstrated that high-resolution isotropic 3D T 2 mapping for knee cartilage characterization is feasible, accurate, repeatable, and precise. The technique allows for multiplanar reformatting and thus T 2 quantification in any plane of interest. 1 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2018;47:362-371. © 2017 International Society for Magnetic Resonance in Medicine.

  19. Three-dimensional radiative transfer in an isotropically scattering, plane-parallel medium: generalized X- and Y-functions

    International Nuclear Information System (INIS)

    Mueller, D.W.; Crosbie, A.L.

    2005-01-01

    The topic of this work is the generalized X- and Y-functions of multidimensional radiative transfer. The physical problem considered is spatially varying, collimated radiation incident on the upper boundary of an isotropically scattering, plane-parallel medium. An integral transform is used to reduce the three-dimensional transport equation to a one-dimensional form, and a modified Ambarzumian's method is used to derive coupled, integro-differential equations for the source functions at the boundaries of the medium. The resulting equations are said to be in double-integral form because the integration is over both angular variables. Numerical results are presented to illustrate the computational characteristics of the formulation

  20. Comparison of three dimensional isotropic and two dimensional conventional indirect MR arthrography for the diagnosis of rotator cuff tears

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Ji Hyun; Yoon, Young Cheol; Kwon, Jong Won; Yoo, Jae Chul [Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul (Korea, Republic of); Cha, Jang Kyu [Dept. of Radiology, Soonchunhyang University Bucheon Hospital, Bucheon (Korea, Republic of); Jee, Suk Kyoung [Joeun Madi Hospital, Seoul (Korea, Republic of)

    2014-12-15

    To compare the accuracy between a three-dimensional (3D) indirect isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) arthrography and a conventional two-dimensional (2D) T1-weighted sequences of indirect MR arthrography for diagnosing rotator cuff tears. The study was approved by our Institutional Review Board. In total, 205 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery for 206 shoulders were included in this study. Both conventional 2D T1-weighted FSE sequences and 3D isotropic T1-weighted FSE sequence were performed in all patients. Two radiologists evaluated the images for the presence of full- or partial-thickness tears in the supraspinatus-infraspinatus (SSP-ISP) tendons and tears in the subscapularis (SSC) tendons. Using the arthroscopic findings as the reference standard, the diagnostic performances of both methods were analyzed by the area under the receiver operating characteristic curve (AUC). Arthroscopy confirmed 165 SSP-ISP tendon tears and 103 SSC tendon tears. For diagnosing SSP-ISP tendon tears, the AUC values were 0.964 and 0.989 for the 2D sequences and 3D T1-weighted FSE sequence, respectively, in reader I and 0.947 and 0.963, respectively, in reader II. The AUC values for diagnosing SSC tendon tears were 0.921 and 0.925, respectively, for reader I and 0.856 and 0.860, respectively, for reader II. There was no significant difference between the AUC values of the 2D and 3D sequences in either reader for either type of tear. 3D indirect isotropic MR arthrography with FSE sequence and the conventional 2D arthrography are not significantly different in terms of accuracy for diagnosing rotator cuff tears.

  1. Comparison of three dimensional isotropic and two dimensional conventional indirect MR arthrography for the diagnosis of rotator cuff tears

    International Nuclear Information System (INIS)

    Lee, Ji Hyun; Yoon, Young Cheol; Kwon, Jong Won; Yoo, Jae Chul; Cha, Jang Kyu; Jee, Suk Kyoung

    2014-01-01

    To compare the accuracy between a three-dimensional (3D) indirect isotropic T1-weighted fast spin-echo (FSE) magnetic resonance (MR) arthrography and a conventional two-dimensional (2D) T1-weighted sequences of indirect MR arthrography for diagnosing rotator cuff tears. The study was approved by our Institutional Review Board. In total, 205 patients who had undergone indirect shoulder MR arthrography followed by arthroscopic surgery for 206 shoulders were included in this study. Both conventional 2D T1-weighted FSE sequences and 3D isotropic T1-weighted FSE sequence were performed in all patients. Two radiologists evaluated the images for the presence of full- or partial-thickness tears in the supraspinatus-infraspinatus (SSP-ISP) tendons and tears in the subscapularis (SSC) tendons. Using the arthroscopic findings as the reference standard, the diagnostic performances of both methods were analyzed by the area under the receiver operating characteristic curve (AUC). Arthroscopy confirmed 165 SSP-ISP tendon tears and 103 SSC tendon tears. For diagnosing SSP-ISP tendon tears, the AUC values were 0.964 and 0.989 for the 2D sequences and 3D T1-weighted FSE sequence, respectively, in reader I and 0.947 and 0.963, respectively, in reader II. The AUC values for diagnosing SSC tendon tears were 0.921 and 0.925, respectively, for reader I and 0.856 and 0.860, respectively, for reader II. There was no significant difference between the AUC values of the 2D and 3D sequences in either reader for either type of tear. 3D indirect isotropic MR arthrography with FSE sequence and the conventional 2D arthrography are not significantly different in terms of accuracy for diagnosing rotator cuff tears.

  2. The value of MRI three-dimensional reconstruction in diagnosis and therapy of prostate cancer

    International Nuclear Information System (INIS)

    Li Feiyu; Wang Xiaoying; Xu Yufeng; Xiao Jiangxi; Jiang Xuexiang

    2006-01-01

    Objective: To evaluate three-dimensional reconstruction of MRI images in diagnosis and therapy of prostate cancer. Methods: Twenty-eight patients with proven prostate cancers were recruited in this study. Seventeen of them were diagnosed as having prostate cancer according to the ultrasound guided systemic biopsy. Their MR examinations showed fourteen lesions in the peripheral zone and three in the central gland of the prostate. The other eleven patients underwent MR examination after a period of treatment, including endocrinetherapy and brachytherapy. Using endorectal coil, a series of T 2 -weighted images were acquired on the axial plane. These source images were processed by 3D-Doctor software to reconstruct into three-dimensional images. Results: In the fourteen patients with peripheral zone cancer, reconstruction images could display the 3D regions of cancer and the involvement of capsular. The outspread of central gland and the compression of peripheral zone in patients with central gland cancer could be revealed in the same way. The volumetric changes of the lesion and the prostate after endocrinetherapy could also be perceived through these 3 D images. Similarly, radioactive seeds were revealed in a spatial manner that could be easily evaluated. Conclusion: Three-dimensional reconstruction images were obtained in all patients. They were able to provide stereotyped information about the lesions and their surrounding tissues. MRI three-dimensional reconstruction can be an adjunctive tool in the evaluation of prostate lesions. (authors)

  3. MRI of the lateral ankle ligaments: value of three-dimensional orientation

    International Nuclear Information System (INIS)

    Mayerhoefer, M.E.; Breitenseher, M.J.

    2003-01-01

    Purpose: To determine the three-dimensional orientation of the lateral ankle ligaments with MRI. Materials and Methods: Twenty healthy volunteers without previous injury to the ankle were included in the study. With the right ankle in the normal anatomic position stabilized in a splint, coronal T2-weighted spin-echo sequences (TSE) were obtained. The three-dimensional orientation was determined by placing paths through the ligaments and by measuring the angles between corresponding tangents and the three main imaging planes. Results: Using the calculated angles, full-length visualization of the lateral ligaments of the ankle was achieved. The angles deviating from the axial imaging plane were 18.0 degrees for the anterior talofibular ligament, 52.3 degrees for the calcaneofibular ligament and 28.2 degrees for the posterior talofibular ligament. Conclusion: MRI enables the exact determination of the three-dimensional orientation of the lateral ankle ligaments. Orienting the imaging planes according to the calculated angular deviation allows the full-length visualization of the ligaments and is the basis for optimal imaging of the lateral ankle ligaments. (orig.) [de

  4. Computational modeling for prediction of the shear stress of three-dimensional isotropic and aligned fiber networks.

    Science.gov (United States)

    Park, Seungman

    2017-09-01

    Interstitial flow (IF) is a creeping flow through the interstitial space of the extracellular matrix (ECM). IF plays a key role in diverse biological functions, such as tissue homeostasis, cell function and behavior. Currently, most studies that have characterized IF have focused on the permeability of ECM or shear stress distribution on the cells, but less is known about the prediction of shear stress on the individual fibers or fiber networks despite its significance in the alignment of matrix fibers and cells observed in fibrotic or wound tissues. In this study, I developed a computational model to predict shear stress for different structured fibrous networks. To generate isotropic models, a random growth algorithm and a second-order orientation tensor were employed. Then, a three-dimensional (3D) solid model was created using computer-aided design (CAD) software for the aligned models (i.e., parallel, perpendicular and cubic models). Subsequently, a tetrahedral unstructured mesh was generated and flow solutions were calculated by solving equations for mass and momentum conservation for all models. Through the flow solutions, I estimated permeability using Darcy's law. Average shear stress (ASS) on the fibers was calculated by averaging the wall shear stress of the fibers. By using nonlinear surface fitting of permeability, viscosity, velocity, porosity and ASS, I devised new computational models. Overall, the developed models showed that higher porosity induced higher permeability, as previous empirical and theoretical models have shown. For comparison of the permeability, the present computational models were matched well with previous models, which justify our computational approach. ASS tended to increase linearly with respect to inlet velocity and dynamic viscosity, whereas permeability was almost the same. Finally, the developed model nicely predicted the ASS values that had been directly estimated from computational fluid dynamics (CFD). The present

  5. Isotropic three-dimensional fast spin-echo Cube magnetic resonance dacryocystography: comparison with the three-dimensional fast-recovery fast spin-echo technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Jing; Chen, Lang; Wang, Qiu-Xia; Zhu, Wen-Zhen; Luo, Xin; Peng, Li [Huazhong University of Science and Technology, Department of Radiology, Tongji Hospital, Wuhan (China); Liu, Rong [Huazhong University of Science and Technology, Department of Ophthalmology, Tongji Hospital, Wuhan (China); Xiong, Wei [GE Healthcare China Wuhan Office, Wuhan (China)

    2015-04-01

    Three-dimensional fast spin-echo Cube (3D-FSE-Cube) uses modulated refocusing flip angles and autocalibrates two dimensional (2D)-accelerated parallel and nonlinear view ordering to produce high-quality volumetric image sets with high-spatial resolution. Furthermore, 3D-FSE-Cube with topical instillation of fluid can also be used for magnetic resonance dacryocystography (MRD) with good soft tissue contrast. The purpose of this study was to evaluate the technical quality and visualization of the lacrimal drainage system (LDS) when using the 3D-FSE-Cube sequence and the 3D fast-recovery fast spin-echo (FRFSE) sequence. In total, 75 patients with primary LDS outflow impairment or postsurgical recurrent epiphora underwent 3D-FSE-Cube MRD and 3D-FRFSE MRD at 3.0 T after topical administration of compound sodium chloride eye drops. Two radiologists graded the images from either of the two sequences in a blinded fashion, and appropriate statistical tests were used to assess differences in technical quality, visibility of ductal segments, and number of segments visualized per LDS. Obstructions were confirmed in 90 of the 150 LDSs assessed. The technical quality of 3D-FSE-Cube MRD and 3D-FRFSE MRD was statistically equivalent (P = 0.871). However, compared with 3D-FRFSE MRD, 3D-FSE-Cube MRD improved the overall visibility and the visibility of the upper drainage segments in normal and obstructed LDSs (P < 0.001). There was a corresponding increase in the number of segments visualized per LDS in both groups (P < 0.001). Compared with 3D-FRFSE MRD, 3D-FSE-Cube MRD potentially improves the visibility of the LDS. (orig.)

  6. Three-dimensional coupled thermoelastodynamic stress and flux induced wave propagation for isotropic half-space with scalar potential functions

    Science.gov (United States)

    Hayati, Yazdan; Eskandari-Ghadi, Morteza

    2018-02-01

    An asymmetric three-dimensional thermoelastodynamic wave propagation with scalar potential functions is presented for an isotropic half-space, in such a way that the wave may be originated from an arbitrary either traction or heat flux applied on a patch at the free surface of the half-space. The displacements, stresses and temperature are presented within the framework of Biot's coupled thermoelasticity formulations. By employing a complete representation for the displacement and temperature fields in terms of two scalar potential functions, the governing equations of coupled thermoelasticity are uncoupled into a sixth- and a second-order partial differential equation in cylindrical coordinate system. By virtue of Fourier expansion and Hankel integral transforms, the angular and radial variables are suppressed respectively, and a 6{th}- and a 2{nd}-order ordinary differential equation in terms of depth are received, which are solved readily, from which the displacement, stresses and temperature fields are derived in transformed space by satisfying both the regularity and boundary conditions. By applying the inverse Hankel integral transforms, the displacements and temperature are numerically evaluated to determine the solutions in the real space. The numerical evaluations are done for three specific cases of vertical and horizontal time-harmonic patch traction and a constant heat flux passing through a circular disc on the surface of the half-space. It has been previously proved that the potential functions used in this paper are applicable from elastostatics to thermoelastodynamics. Thus, the analytical solutions presented in this paper are verified by comparing the results of this study with two specific problems reported in the literature, which are an elastodynamic problem and an axisymmetric quasi-static thermoelastic problem. To show the accuracy of numerical results, the solution of this study is also compared with the solution for elastodynamics exists in

  7. Three-dimensional contrasted visualization of pancreas in rats using clinical MRI and CT scanners.

    Science.gov (United States)

    Yin, Ting; Coudyzer, Walter; Peeters, Ronald; Liu, Yewei; Cona, Marlein Miranda; Feng, Yuanbo; Xia, Qian; Yu, Jie; Jiang, Yansheng; Dymarkowski, Steven; Huang, Gang; Chen, Feng; Oyen, Raymond; Ni, Yicheng

    2015-01-01

    The purpose of this work was to visualize the pancreas in post-mortem rats with local contrast medium infusion by three-dimensional (3D) magnetic resonance imaging (MRI) and computed tomography (CT) using clinical imagers. A total of 16 Sprague Dawley rats of about 300 g were used for the pancreas visualization. Following the baseline imaging, a mixed contrast medium dye called GadoIodo-EB containing optimized concentrations of Gd-DOTA, iomeprol and Evens blue was infused into the distally obstructed common bile duct (CBD) for post-contrast imaging with 3.0 T MRI and 128-slice CT scanners. Images were post-processed with the MeVisLab software package. MRI findings were co-registered with CT scans and validated with histomorphology, with relative contrast ratios quantified. Without contrast enhancement, the pancreas was indiscernible. After infusion of GadoIodo-EB solution, only the pancreatic region became outstandingly visible, as shown by 3D rendering MRI and CT and proven by colored dissection and histological examinations. The measured volume of the pancreas averaged 1.12 ± 0.04 cm(3) after standardization. Relative contrast ratios were 93.28 ± 34.61% and 26.45 ± 5.29% for MRI and CT respectively. We have developed a multifunctional contrast medium dye to help clearly visualize and delineate rat pancreas in situ using clinical MRI and CT scanners. The topographic landmarks thus created with 3D demonstration may help to provide guidelines for the next in vivo pancreatic MRI research in rodents. Copyright © 2015 John Wiley & Sons, Ltd.

  8. Evaluation of anterior pituitary gland volume in childhood using three-dimensional MRI

    International Nuclear Information System (INIS)

    Marziali, Simone; Gaudiello, Fabrizio; Ferone, Ernesto; Colangelo, Vittorio; Floris, Roberto; Simonetti, Giovanni; Bozzao, Alessandro; Scire, Giuseppe; Simonetti, Alessandra; Boscherini, Brunetto

    2004-01-01

    Background: Three-dimensional MRI (3D-MRI) is a reliable tool for the evaluation of anatomical volumes. Volumetric measurement of the normal anterior pituitary gland in childhood has been performed in the past by 2D-MRI calculations, but has inherent inaccuracies. Objective: To obtain accurate normal anterior pituitary gland volume in childhood using 3D-MRI coronal sections. Materials and methods: The anterior pituitary gland was measured using coronal T1-weighted 3D-gradient-echo sequences (section thickness 0.75 mm). The study group was composed of 95 prepubertal children (age range 2 months-10 years) with clinically normal pituitary function and no pituitary or brain abnormalities. Results: A measurement error of 0.2-0.4% was assessed by using a phantom study. Volumetric evaluation of the anterior pituitary gland showed progressive growth of the gland from a mean 131±24 mm 3 at 2-12 months, to 249±25 mm 3 at 1-4 years and 271±29 mm 3 at 5-10 years. Conclusions: These data may be useful for paediatricians in the evaluation of patients with neuroendocrine diseases, in particular growth hormone deficiency. (orig.)

  9. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    International Nuclear Information System (INIS)

    De Deene, Y.; De Wagter, C.; Van Duyse, B.; Achten, E.; De Neve, W.; De Poorter, J.

    1995-01-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes

  10. Three dimensional gel dosimetry by use of nuclear magnetic resonance imaging (MRI)

    Energy Technology Data Exchange (ETDEWEB)

    De Deene, Y; De Wagter, C; Van Duyse, B; Achten, E; De Neve, W [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde; De Poorter, J [Ghent Univ. (Belgium). Dept. of Magnetic Resonance

    1995-12-01

    As co-monomers are found to polymerize by radiation, they are eligible for constructing a three dimensional dosimeter. Another kind of three dimensional dosimeter, based on the radiation sensitivity of the ferrous ions in a Fricke solution, was tested in a previous study. However, a major problem that occurs in this kind of gel dosimeters is the diffusion of the ferric and ferrous ions. The co-monomer gels are more stable. The degree of polymerisation is visualized with a clinical MRI system. Acrylamide and N,N-methylene-bis-acrylamide are dissolved in a gel composed of gelatin and water. By irradiation the co-monomers are polymerized to polyacrylamide. The gel is casted in humanoid forms. As such, a simulation of the irradiation of the patient can be performed. Magnetic resonance relaxivity images of the irradiated gel display the irradiation dose. The images of the gel are fused with the radiological images of the patient. Quantitation of the dose response of the co-monomer gel is obtained through calibration by test tubes.

  11. Three-dimensional dictionary-learning reconstruction of (23)Na MRI data.

    Science.gov (United States)

    Behl, Nicolas G R; Gnahm, Christine; Bachert, Peter; Ladd, Mark E; Nagel, Armin M

    2016-04-01

    To reduce noise and artifacts in (23)Na MRI with a Compressed Sensing reconstruction and a learned dictionary as sparsifying transform. A three-dimensional dictionary-learning compressed sensing reconstruction algorithm (3D-DLCS) for the reconstruction of undersampled 3D radial (23)Na data is presented. The dictionary used as the sparsifying transform is learned with a K-singular-value-decomposition (K-SVD) algorithm. The reconstruction parameters are optimized on simulated data, and the quality of the reconstructions is assessed with peak signal-to-noise ratio (PSNR) and structural similarity (SSIM). The performance of the algorithm is evaluated in phantom and in vivo (23)Na MRI data of seven volunteers and compared with nonuniform fast Fourier transform (NUFFT) and other Compressed Sensing reconstructions. The reconstructions of simulated data have maximal PSNR and SSIM for an undersampling factor (USF) of 10 with numbers of averages equal to the USF. For 10-fold undersampling, the PSNR is increased by 5.1 dB compared with the NUFFT reconstruction, and the SSIM by 24%. These results are confirmed by phantom and in vivo (23)Na measurements in the volunteers that show markedly reduced noise and undersampling artifacts in the case of 3D-DLCS reconstructions. The 3D-DLCS algorithm enables precise reconstruction of undersampled (23)Na MRI data with markedly reduced noise and artifact levels compared with NUFFT reconstruction. Small structures are well preserved. © 2015 Wiley Periodicals, Inc.

  12. Ventricular enlargement in multiple sclerosis: a comparison of three-dimensional and linear MRI estimates

    International Nuclear Information System (INIS)

    Turner, B.; Blumhardt, L.D.; Ramli, N.; Jaspan, T.

    2001-01-01

    Atrophy of central white matter is related to irreversible clinical disability in multiple sclerosis (MS) and ventricular enlargement may be a sensitive marker of this tissue loss. Therapeutic trials in MS have provided MRI data for investigation of cerebral atrophy in MS. These studies use almost exclusively two-dimensional (2-D) images, which may be limited in the assessment of three-dimensional (3-D) structures. We used 3-D MRI data to estimate ventricular volumes in 40 patients with MS and 10 healthy controls, to look at associations with clinical disability and the stage of the disease. We then compared simple linear measures of ventricular size from conventional 2-D images, with 3-D volume estimates to establish the best available linear indices of ventricular volume. Mean ventricular volumes were increased in the patients and significantly larger in the more disabled patients. The estimated volume of the third ventricle obtained from 3-D MRI showed the strongest association with the clinical stage of the disease, duration of symptoms and levels of disability. Finally, we confirmed that in patients with MS accurate data on ventricular size can be obtained from 2-D images by two simple and convenient linear measures, the width of the third ventricle and of the anterior horn of the lateral ventricle. (orig.)

  13. Three-dimensional liver motion tracking using real-time two-dimensional MRI.

    Science.gov (United States)

    Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

    2014-04-01

    Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Axial, sagittal, and coronal 2D MRI series

  14. Three-dimensional liver motion tracking using real-time two-dimensional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Brix, Lau, E-mail: lau.brix@stab.rm.dk [Department of Procurement and Clinical Engineering, Region Midt, Olof Palmes Allé 15, 8200 Aarhus N, Denmark and MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Ringgaard, Steffen [MR Research Centre, Aarhus University Hospital, Skejby, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Sørensen, Thomas Sangild [Department of Computer Science, Aarhus University, Aabogade 34, 8200 Aarhus N, Denmark and Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N (Denmark); Poulsen, Per Rugaard [Department of Clinical Medicine, Aarhus University, Brendstrupgaardsvej 100, 8200 Aarhus N, Denmark and Department of Oncology, Aarhus University Hospital, Nørrebrogade 44, 8000 Aarhus C (Denmark)

    2014-04-15

    Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

  15. Three-dimensional liver motion tracking using real-time two-dimensional MRI

    International Nuclear Information System (INIS)

    Brix, Lau; Ringgaard, Steffen; Sørensen, Thomas Sangild; Poulsen, Per Rugaard

    2014-01-01

    Purpose: Combined magnetic resonance imaging (MRI) systems and linear accelerators for radiotherapy (MR-Linacs) are currently under development. MRI is noninvasive and nonionizing and can produce images with high soft tissue contrast. However, new tracking methods are required to obtain fast real-time spatial target localization. This study develops and evaluates a method for tracking three-dimensional (3D) respiratory liver motion in two-dimensional (2D) real-time MRI image series with high temporal and spatial resolution. Methods: The proposed method for 3D tracking in 2D real-time MRI series has three steps: (1) Recording of a 3D MRI scan and selection of a blood vessel (or tumor) structure to be tracked in subsequent 2D MRI series. (2) Generation of a library of 2D image templates oriented parallel to the 2D MRI image series by reslicing and resampling the 3D MRI scan. (3) 3D tracking of the selected structure in each real-time 2D image by finding the template and template position that yield the highest normalized cross correlation coefficient with the image. Since the tracked structure has a known 3D position relative to each template, the selection and 2D localization of a specific template translates into quantification of both the through-plane and in-plane position of the structure. As a proof of principle, 3D tracking of liver blood vessel structures was performed in five healthy volunteers in two 5.4 Hz axial, sagittal, and coronal real-time 2D MRI series of 30 s duration. In each 2D MRI series, the 3D localization was carried out twice, using nonoverlapping template libraries, which resulted in a total of 12 estimated 3D trajectories per volunteer. Validation tests carried out to support the tracking algorithm included quantification of the breathing induced 3D liver motion and liver motion directionality for the volunteers, and comparison of 2D MRI estimated positions of a structure in a watermelon with the actual positions. Results: Axial, sagittal

  16. Three-dimensional versus two-dimensional sonography of the temporomandibular joint in comparison to MRI

    Energy Technology Data Exchange (ETDEWEB)

    Landes, Constantin A. [Oral, Maxillofacial and Plastic Facial Surgery, Frankfurt University Medical Centre, Theodor-Stern-Kai 7, 60596 Frankfurt (Germany)]. E-mail: c.landes@lycos.com; Goral, Wojciech A. [Oral, Maxillofacial and Plastic Facial Surgery, Frankfurt University Medical Centre, Theodor-Stern-Kai 7, 60596 Frankfurt (Germany)]. E-mail: w.goral@gmx.de; Sader, Robert [Oral, Maxillofacial and Plastic Facial Surgery, Frankfurt University Medical Centre, Theodor-Stern-Kai 7, 60596 Frankfurt (Germany)]. E-mail: r.sader@em.uni-frankfurt.de; Mack, Martin G. [Department of Diagnostic and Interventional Radiology, Frankfurt University Medical Centre, Theodor-Stern-Kai 7, 60596 Frankfurt (Germany)]. E-mail: martinmack@arcor.de

    2007-02-15

    Aim: To compare clinical feasibility of static two-dimensional (2D) to three-dimensional (3D) sonography of the temporomandibular joint (TMJ) in assessment of disk dislocation and joint degeneration compared to magnetic resonance imaging (MRI). Method: Thirty-three patients, 66 TMJ were prospectively sonographed 2D and 3D (8-12.5 MHz step motor scan), in occlusion and maximum opening with a probe position parallel inferior to the zygomatic arch. Axial 2D images were judged independent from the 3D scans; 3D volumes were cut axial, sagittal, frontal and rotated in real-time. Disk position and joint degeneration were assessed and compared to a subsequent MRI examination. Results: The specific appearance of the disk was hypoechogenic overlying a hyperechogenic condyle in axial (2D) or sagittal and frontal (3D) viewing. Specificity of 2D sonography for disk dislocation was 63%, sensitivity 58%, accuracy 64%, positive predictive value 46%, negative predictive value 73%; for joint degeneration synonymously 59/68/61/38/83%. 3D sonography for disk displacement reached synonymously 68/60/69/51/76%, for joint degeneration 75/65/73/48/86%. 2D sonographic diagnoses of disk dislocation in the closed mouth position and of joint degeneration showed significantly different results from the expected values (MRI) in {chi} {sup 2} testing; 3D diagnoses of disk dislocation in closed mouth position, of joint degeneration, 2D and 3D diagnoses in open mouth position were nonsignificant. Conclusions: Acceptable was the overall negative predictive value, as specificity and accuracy for joint degeneration in 3D. 3D appears superior diagnosing disk dislocation in closed mouth position as for overall joint degeneration. Sensitivity, accuracy and positive predictive value will have to ameliorate with future equipment of higher resolution in real-time 2D and 3D, if sonographic screening shall be clinically applied prior to MRI.

  17. Isotropic Kink and Quasiparticle Excitations in the Three-Dimensional Perovskite Manganite La_{0.6}Sr_{0.4}MnO_{3}.

    Science.gov (United States)

    Horiba, Koji; Kitamura, Miho; Yoshimatsu, Kohei; Minohara, Makoto; Sakai, Enju; Kobayashi, Masaki; Fujimori, Atsushi; Kumigashira, Hiroshi

    2016-02-19

    In order to reveal the many-body interactions in three-dimensional perovskite manganites that show colossal magnetoresistance, we performed an in situ angle-resolved photoemission spectroscopy on La_{0.6}Sr_{0.4}MnO_{3} and investigated the behavior of quasiparticles. We observed quasiparticle peaks near the Fermi momentum in both the electron and the hole bands, and clear kinks throughout the entire hole Fermi surface in the band dispersion. This isotropic behavior of quasiparticles and kinks suggests that polaronic quasiparticles produced by the coupling of electrons with Jahn-Teller phonons play an important role in the colossal magnetoresistance properties of the ferromagnetic metallic phase of three-dimensional manganites.

  18. Comparison of three-dimensional isotropic and conventional MR arthrography with respect to the diagnosis of rotator cuff and labral lesions: Focus on isotropic fat-suppressed proton density and VIBE sequences

    International Nuclear Information System (INIS)

    Park, S.Y.; Lee, I.S.; Park, S.K.; Cheon, S.J.; Ahn, J.M.; Song, J.W.

    2014-01-01

    Aim: To compare the diagnostic accuracies of three-dimensional (3D) isotropic magnetic resonance arthrography (MRA) using fat-suppressed proton density (PD) or volume interpolated breath-hold examination (VIBE) sequences with that of conventional MRA for the diagnosis of rotator cuff and labral lesions. Materials and methods: Eighty-six patients who underwent arthroscopic surgery were included. 3D isotropic sequences were performed in the axial plane using fat-suppressed PD (group A) in 53 patients and using VIBE (group B) in 33 patients. Reformatted images were obtained corresponding to conventional images, and evaluated for the presence of labral and rotator cuff lesions using conventional and 3D isotropic sequences. The diagnostic performances of each sequence were determined using arthroscopic findings as the standard. Results: Good to excellent interobserver agreements were obtained for both 3D isotropic sequences for the evaluation of rotator cuff and labral lesions. Excellent agreement was found between two-dimensional (2D) and 3D isotropic MRA, except for supraspinatus tendon (SST) tears by both readers and for subscapularis tendon (SCT) tears by reader 2 in group B. 2D MRA and 3D isotropic sequences had high diagnostic performances for rotator and labral tears, and the difference between the two imaging methods was insignificant. Conclusions: The diagnostic performances of 3D isotropic VIBE and PD sequences were similar to those of 2D MRA

  19. High-Resolution Isotropic Three-Dimensional MR Imaging of the Extraforaminal Segments of the Cranial Nerves.

    Science.gov (United States)

    Wen, Jessica; Desai, Naman S; Jeffery, Dean; Aygun, Nafi; Blitz, Ari

    2018-02-01

    High-resolution isotropic 3-dimensional (D) MR imaging with and without contrast is now routinely used for imaging evaluation of cranial nerve anatomy and pathologic conditions. The anatomic details of the extraforaminal segments are well-visualized on these techniques. A wide range of pathologic entities may cause enhancement or displacement of the nerve, which is now visible to an extent not available on standard 2D imaging. This article highlights the anatomy of extraforaminal segments of the cranial nerves and uses select cases to illustrate the utility and power of these sequences, with a focus on constructive interference in steady-state. Copyright © 2017 Elsevier Inc. All rights reserved.

  20. Three-dimensional textural features of conventional MRI improve diagnostic classification of childhood brain tumours.

    Science.gov (United States)

    Fetit, Ahmed E; Novak, Jan; Peet, Andrew C; Arvanitits, Theodoros N

    2015-09-01

    The aim of this study was to assess the efficacy of three-dimensional texture analysis (3D TA) of conventional MR images for the classification of childhood brain tumours in a quantitative manner. The dataset comprised pre-contrast T1 - and T2-weighted MRI series obtained from 48 children diagnosed with brain tumours (medulloblastoma, pilocytic astrocytoma and ependymoma). 3D and 2D TA were carried out on the images using first-, second- and higher order statistical methods. Six supervised classification algorithms were trained with the most influential 3D and 2D textural features, and their performances in the classification of tumour types, using the two feature sets, were compared. Model validation was carried out using the leave-one-out cross-validation (LOOCV) approach, as well as stratified 10-fold cross-validation, in order to provide additional reassurance. McNemar's test was used to test the statistical significance of any improvements demonstrated by 3D-trained classifiers. Supervised learning models trained with 3D textural features showed improved classification performances to those trained with conventional 2D features. For instance, a neural network classifier showed 12% improvement in area under the receiver operator characteristics curve (AUC) and 19% in overall classification accuracy. These improvements were statistically significant for four of the tested classifiers, as per McNemar's tests. This study shows that 3D textural features extracted from conventional T1 - and T2-weighted images can improve the diagnostic classification of childhood brain tumours. Long-term benefits of accurate, yet non-invasive, diagnostic aids include a reduction in surgical procedures, improvement in surgical and therapy planning, and support of discussions with patients' families. It remains necessary, however, to extend the analysis to a multicentre cohort in order to assess the scalability of the techniques used. Copyright © 2015 John Wiley & Sons, Ltd.

  1. MRI definition of target volumes using fuzzy logic method for three-dimensional conformal radiation therapy

    International Nuclear Information System (INIS)

    Caudrelier, Jean-Michel; Vial, Stephane; Gibon, David; Kulik, Carine; Fournier, Charles; Castelain, Bernard; Coche-Dequeant, Bernard; Rousseau, Jean

    2003-01-01

    Purpose: Three-dimensional (3D) volume determination is one of the most important problems in conformal radiation therapy. Techniques of volume determination from tomographic medical imaging are usually based on two-dimensional (2D) contour definition with the result dependent on the segmentation method used, as well as on the user's manual procedure. The goal of this work is to describe and evaluate a new method that reduces the inaccuracies generally observed in the 2D contour definition and 3D volume reconstruction process. Methods and Materials: This new method has been developed by integrating the fuzziness in the 3D volume definition. It first defines semiautomatically a minimal 2D contour on each slice that definitely contains the volume and a maximal 2D contour that definitely does not contain the volume. The fuzziness region in between is processed using possibility functions in possibility theory. A volume of voxels, including the membership degree to the target volume, is then created on each slice axis, taking into account the slice position and slice profile. A resulting fuzzy volume is obtained after data fusion between multiorientation slices. Different studies have been designed to evaluate and compare this new method of target volume reconstruction and a classical reconstruction method. First, target definition accuracy and robustness were studied on phantom targets. Second, intra- and interobserver variations were studied on radiosurgery clinical cases. Results: The absolute volume errors are less than or equal to 1.5% for phantom volumes calculated by the fuzzy logic method, whereas the values obtained with the classical method are much larger than the actual volumes (absolute volume errors up to 72%). With increasing MRI slice thickness (1 mm to 8 mm), the phantom volumes calculated by the classical method are increasing exponentially with a maximum absolute error up to 300%. In contrast, the absolute volume errors are less than 12% for phantom

  2. Three-dimensional inversion recovery manganese-enhanced MRI of mouse brain using super-resolution reconstruction to visualize nuclei involved in higher brain function.

    Science.gov (United States)

    Poole, Dana S; Plenge, Esben; Poot, Dirk H J; Lakke, Egbert A J F; Niessen, Wiro J; Meijering, Erik; van der Weerd, Louise

    2014-07-01

    The visualization of activity in mouse brain using inversion recovery spin echo (IR-SE) manganese-enhanced MRI (MEMRI) provides unique contrast, but suffers from poor resolution in the slice-encoding direction. Super-resolution reconstruction (SRR) is a resolution-enhancing post-processing technique in which multiple low-resolution slice stacks are combined into a single volume of high isotropic resolution using computational methods. In this study, we investigated, first, whether SRR can improve the three-dimensional resolution of IR-SE MEMRI in the slice selection direction, whilst maintaining or improving the contrast-to-noise ratio of the two-dimensional slice stacks. Second, the contrast-to-noise ratio of SRR IR-SE MEMRI was compared with a conventional three-dimensional gradient echo (GE) acquisition. Quantitative experiments were performed on a phantom containing compartments of various manganese concentrations. The results showed that, with comparable scan times, the signal-to-noise ratio of three-dimensional GE acquisition is higher than that of SRR IR-SE MEMRI. However, the contrast-to-noise ratio between different compartments can be superior with SRR IR-SE MEMRI, depending on the chosen inversion time. In vivo experiments were performed in mice receiving manganese using an implanted osmotic pump. The results showed that SRR works well as a resolution-enhancing technique in IR-SE MEMRI experiments. In addition, the SRR image also shows a number of brain structures that are more clearly discernible from the surrounding tissues than in three-dimensional GE acquisition, including a number of nuclei with specific higher brain functions, such as memory, stress, anxiety and reward behavior. Copyright © 2014 John Wiley & Sons, Ltd.

  3. Computer-assisted three-dimensional reconstruction of the corticospinal system as a reference for CT and MRI

    Energy Technology Data Exchange (ETDEWEB)

    Buhmann, C. [Department of Neuroanatomy, Hannover Medical School (Germany)]|[University Hospital Eppendorf, Hamburg (Germany); Kretschmann, H.J. [Department of Neuroanatomy, Hannover Medical School (Germany)

    1998-09-01

    We present a three-dimensional (3D) anatomical computer-graphics model of the corticospinal system acquired from equidistant serial anatomical slices of six intracranially-fixed human brains. This model is part of a neuroanatomical reference system (NeuRef) which enables 3D visualization of the brain and shows the relationship of its components such as anatomical structures, functional fibre tracts and arteries. Sections through the models can be matched with corresponding CT or MR images. This allows the probable localisation of corticospinal fibres on CT or MRI. (orig.) (orig.) With 18 figs., 3 tabs., 40 refs.

  4. Computer-assisted three-dimensional reconstruction of the corticospinal system as a reference for CT and MRI

    International Nuclear Information System (INIS)

    Buhmann, C.; Kretschmann, H.J.

    1998-01-01

    We present a three-dimensional (3D) anatomical computer-graphics model of the corticospinal system acquired from equidistant serial anatomical slices of six intracranially-fixed human brains. This model is part of a neuroanatomical reference system (NeuRef) which enables 3D visualization of the brain and shows the relationship of its components such as anatomical structures, functional fibre tracts and arteries. Sections through the models can be matched with corresponding CT or MR images. This allows the probable localisation of corticospinal fibres on CT or MRI. (orig.) (orig.)

  5. Three-dimensional evaluation of lumbar disc hernia and prediction of absorption by enhanced MRI

    International Nuclear Information System (INIS)

    Kawaji, Youichi; Uchiyama, Seiji; Yagi, Eiichi

    2001-01-01

    Both the spontaneous shrinkage and the disappearance of disc hernia have been confirmed through the use of computed tomography (CT) and magnetic resonance imaging (MRI). There is, however, no practical method to predict the likely absorption of the herniated mass. The objective of this study was to predict the spontaneous absorption of disc hernia by MRI, and to select the optimum treatment. The study involved 65 patients with lumbar disc hernias. Conservative treatment was carried out in 21 patients, while 44 patients underwent herniotomy. In the nonoperated patients, an MRI was taken both during the painful period, and shortly after pain remission. Hernial shrinkage was evaluated according to the decrease in the calculated volume, in addition to the decrease in hernial area, calculated by MRI. In the operated group, preoperative MRI enhancement, type of hernia, and invasion of granulation tissue in the histological specimens were studied. In the 21 nonoperated patients, the volume (mean ±SD) was 0.488±208 cm 3 (range, 0.197-0.931 cm 3 ) in the painful period and 0.214±0.181 cm 3 (range, 0.0-0.744 cm 3 ) in the remission period. This decrease in volume was statistically significant. There was also a greater decrease in hernias exhibiting positive enhancement by MRI. In the operated patients, hernias that penetrated the posterior longitudinal ligament (PLL) had high rates of preoperative enhancement, and these hernias showed invasion of granulation tissue with marked neovascularization. Positive enhancement by MRI confirms an ongoing absorption process. Enhanced MRI can be a good method for the prediction of spontaneous absorption of lumbar disc hernias. (author)

  6. Three-dimensional evaluation of lumbar disc hernia and prediction of absorption by enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kawaji, Youichi; Uchiyama, Seiji [Niigata Univ. (Japan). School of Medicine; Yagi, Eiichi

    2001-07-01

    Both the spontaneous shrinkage and the disappearance of disc hernia have been confirmed through the use of computed tomography (CT) and magnetic resonance imaging (MRI). There is, however, no practical method to predict the likely absorption of the herniated mass. The objective of this study was to predict the spontaneous absorption of disc hernia by MRI, and to select the optimum treatment. The study involved 65 patients with lumbar disc hernias. Conservative treatment was carried out in 21 patients, while 44 patients underwent herniotomy. In the nonoperated patients, an MRI was taken both during the painful period, and shortly after pain remission. Hernial shrinkage was evaluated according to the decrease in the calculated volume, in addition to the decrease in hernial area, calculated by MRI. In the operated group, preoperative MRI enhancement, type of hernia, and invasion of granulation tissue in the histological specimens were studied. In the 21 nonoperated patients, the volume (mean {+-}SD) was 0.488{+-}208 cm{sup 3} (range, 0.197-0.931 cm{sup 3}) in the painful period and 0.214{+-}0.181 cm{sup 3} (range, 0.0-0.744 cm{sup 3}) in the remission period. This decrease in volume was statistically significant. There was also a greater decrease in hernias exhibiting positive enhancement by MRI. In the operated patients, hernias that penetrated the posterior longitudinal ligament (PLL) had high rates of preoperative enhancement, and these hernias showed invasion of granulation tissue with marked neovascularization. Positive enhancement by MRI confirms an ongoing absorption process. Enhanced MRI can be a good method for the prediction of spontaneous absorption of lumbar disc hernias. (author)

  7. A three-dimensional stereotaxic MRI brain atlas of the cichlid fish Oreochromis mossambicus.

    Science.gov (United States)

    Simões, José M; Teles, Magda C; Oliveira, Rui F; Van der Linden, Annemie; Verhoye, Marleen

    2012-01-01

    The African cichlid Oreochromis mossambicus (Mozambique tilapia) has been used as a model system in a wide range of behavioural and neurobiological studies. The increasing number of genetic tools available for this species, together with the emerging interest in its use for neurobiological studies, increased the need for an accurate hodological mapping of the tilapia brain to supplement the available histological data. The goal of our study was to elaborate a three-dimensional, high-resolution digital atlas using magnetic resonance imaging, supported by Nissl staining. Resulting images were viewed and analysed in all orientations (transverse, sagittal, and horizontal) and manually labelled to reveal structures in the olfactory bulb, telencephalon, diencephalon, optic tectum, and cerebellum. This high resolution tilapia brain atlas is expected to become a very useful tool for neuroscientists using this fish model and will certainly expand their use in future studies regarding the central nervous system.

  8. Three-dimensional motion analysis of an improved head immobilization system for simulation, CT, MRI, and PET imaging

    International Nuclear Information System (INIS)

    Thornton, A.F. Jr.; Ten Haken, R.K.; Gerhardsson, A.; Correll, M.

    1991-01-01

    A mask/marker immobilization system for the routine radiation therapy treatment of head and neck disease is described, utilizing a commercially available thermoplastic mesh, indexed and mounted for a rigid frame attached to the therapy couch. Designed to permit CT, MRI, and PET diagnostics scans of the patient to be performed in the simulation and treatment position employing the same mask, the system has been tested in order to demonstrate the reproducibility of immobilization throughout a radical course of irradiation. Three-dimensional analysis of patient position over an 8-week course of daily radiation treatment has been performed for 9 patients from digitization of anatomic points identified on orthogonal radiographs. Studies employing weekly constructed system permits rapid mask formation to be performed on the treatment simulator, resulting in an immobilization device comparable to masks produced with vacuum-forming techniques. Details of motion analysis and central axis CT, MRI, and PET markers are offered. (author). 16 refs.; 3 figs

  9. Dynamic Three-Dimensional Shoulder Mri during Active Motion for Investigation of Rotator Cuff Diseases.

    Directory of Open Access Journals (Sweden)

    Christine Tempelaere

    Full Text Available MRI is the standard methodology in diagnosis of rotator cuff diseases. However, many patients continue to have pain despite treatment, and MRI of a static unloaded shoulder seems insufficient for best diagnosis and treatment. This study evaluated if Dynamic MRI provides novel kinematic data that can be used to improve the understanding, diagnosis and best treatment of rotator cuff diseases.Dynamic MRI provided real-time 3D image series and was used to measure changes in the width of subacromial space, superior-inferior translation and anterior-posterior translation of the humeral head relative to the glenoid during active abduction. These measures were investigated for consistency with the rotator cuff diseases classifications from standard MRI.The study included: 4 shoulders with massive rotator cuff tears, 5 shoulders with an isolated full-thickness supraspinatus tear, 5 shoulders with tendinopathy and 6 normal shoulders. A change in the width of subacromial space greater than 4mm differentiated between rotator cuff diseases with tendon tears (massive cuff tears and supraspinatus tear and without tears (tendinopathy (p = 0.012. The range of the superior-inferior translation was higher in the massive cuff tears group (6.4mm than in normals (3.4mm (p = 0.02. The range of the anterior-posterior translation was higher in the massive cuff tears (9.2 mm and supraspinatus tear (9.3 mm shoulders compared to normals (3.5mm and tendinopathy (4.8mm shoulders (p = 0.05.The Dynamic MRI enabled a novel measure; 'Looseness', i.e. the translation of the humeral head on the glenoid during an abduction cycle. Looseness was better able at differentiating different forms of rotator cuff disease than a simple static measure of relative glenohumeral position.

  10. A three-dimensional MRI atlas of the zebra finch brain in stereotaxic coordinates

    DEFF Research Database (Denmark)

    Poirier, Colline; Vellema, Michiel; Verhoye, Marleen

    2008-01-01

    of different brain areas (nuclei) involved in the sensory and motor control of song. Until now, the only published atlases of songbird brains consisted in drawings based on histological slices of the canary and of the zebra finch brain. Taking advantage of high-magnetic field (7 Tesla) MRI technique, we...

  11. Evaluation of the menisci of the knee joint using three-dimensional isotropic resolution fast spin-echo imaging: diagnostic performance in 250 patients with surgical correlation

    Energy Technology Data Exchange (ETDEWEB)

    Kijowski, Richard; Davis, Kirkland W.; Blankenbaker, Donna G.; Woods, Michael A.; De Smet, Arthur A. [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); Munoz del Rio, Alejandro [University of Wisconsin School of Medicine and Public Health, Department of Radiology, Madison, WI (United States); University of Wisconsin School of Medicine and Public Health, Department of Statistics, Madison, WI (United States)

    2012-02-15

    To compare the diagnostic performance of FSE-Cube, a three-dimensional isotropic resolution intermediate-weighted fast spin-echo sequence, with a routine magnetic resonance (MR) protocol at 3.0 T for detecting surgically confirmed meniscal tears of the knee joint in a large patient population. FSE-Cube was added to a routine MR protocol performed at 3.0 T on 250 patients who underwent subsequent knee arthroscopy. Three radiologists independently used FSE-Cube during one review and the routine MR protocol during a second review to detect medial and lateral meniscal tears. Using arthroscopy as the reference standard, the sensitivity and specificity of FSE-Cube and the routine MR protocol for detecting meniscal tears were determined for all readers combined. McNemar's tests were used to compare diagnostic performance between FSE-Cube and the routine MR protocol. FSE-cube and the routine MR protocol had similar sensitivity (95.5%/95.3% respectively, P=0.94) and similar specificity (69.8%/74.0% respectively, P=0.10) for detecting 156 medial meniscal tears. FSE-Cube had significantly lower sensitivity than the routine MR protocol (79.4%/85.0% respectively, P < 0.05) but similar specificity (83.9%/82.2% respectively, P=0.37) for detecting 89 lateral mensical tears. For lateral meniscal tears, FSE-Cube had significantly lower sensitivity (P < 0.05) than the routine MR protocol for detecting 19 root tears but similar sensitivity (P=0.17-1.00) for detecting all other tear locations and types. FSE-Cube had diagnostic performance similar to a routine MR protocol for detecting meniscal tears except for a significantly lower sensitivity for detecting lateral meniscal tears, which was mainly attributed to decreased ability to identify lateral meniscus root tears. (orig.)

  12. Evaluation of the menisci of the knee joint using three-dimensional isotropic resolution fast spin-echo imaging: diagnostic performance in 250 patients with surgical correlation

    International Nuclear Information System (INIS)

    Kijowski, Richard; Davis, Kirkland W.; Blankenbaker, Donna G.; Woods, Michael A.; De Smet, Arthur A.; Munoz del Rio, Alejandro

    2012-01-01

    To compare the diagnostic performance of FSE-Cube, a three-dimensional isotropic resolution intermediate-weighted fast spin-echo sequence, with a routine magnetic resonance (MR) protocol at 3.0 T for detecting surgically confirmed meniscal tears of the knee joint in a large patient population. FSE-Cube was added to a routine MR protocol performed at 3.0 T on 250 patients who underwent subsequent knee arthroscopy. Three radiologists independently used FSE-Cube during one review and the routine MR protocol during a second review to detect medial and lateral meniscal tears. Using arthroscopy as the reference standard, the sensitivity and specificity of FSE-Cube and the routine MR protocol for detecting meniscal tears were determined for all readers combined. McNemar's tests were used to compare diagnostic performance between FSE-Cube and the routine MR protocol. FSE-cube and the routine MR protocol had similar sensitivity (95.5%/95.3% respectively, P=0.94) and similar specificity (69.8%/74.0% respectively, P=0.10) for detecting 156 medial meniscal tears. FSE-Cube had significantly lower sensitivity than the routine MR protocol (79.4%/85.0% respectively, P < 0.05) but similar specificity (83.9%/82.2% respectively, P=0.37) for detecting 89 lateral mensical tears. For lateral meniscal tears, FSE-Cube had significantly lower sensitivity (P < 0.05) than the routine MR protocol for detecting 19 root tears but similar sensitivity (P=0.17-1.00) for detecting all other tear locations and types. FSE-Cube had diagnostic performance similar to a routine MR protocol for detecting meniscal tears except for a significantly lower sensitivity for detecting lateral meniscal tears, which was mainly attributed to decreased ability to identify lateral meniscus root tears. (orig.)

  13. Three-dimensional (3D) MRI of the knee. IRM tridimensionnelle du genou

    Energy Technology Data Exchange (ETDEWEB)

    Shahabpour, M.; Spruyt, D.; Leroux, G.B.; Osteaux, M. (Vrije Univ., Brussels (Belgium))

    1993-01-01

    Three-dimensional gradient echo T2-weighted sequences have a number of advantages over spin echo T2-weighted sequences (or even 2D gradient echo T2-weighted sequences) for assessment of the knee. They allow a multidimensional analysis based on a single acquisition sequence usually obtained in the sagittal plane. Image reconstructions can be performed secondarily in the coronal, axial and oblique planes, particularly along the specific path of the anterior cruciate ligament. By providing ultrathin serial sections, decreasing the partial volume effect, small lesions, such as cartilaginous fissures or flaps and radial meniscal lesions can be detected in the axial plane, for example. This advantage, combined with the marked sensitivity of gradient echo sequences to alterations in the tissue water content, allows the detection of partial tendon ruptures. The reduction of the partial volume effect and chemical shift artefact probably participate in the capacity of these sequences to visualize the two surfaces of the cartilage of the femorotibial joint. Flow artefacts are less of a problem than with 2D imaging, which eliminates the need for techniques such as saturation of the vascular signal or cardiac gating. A disadvantage of these gradient echo sequences (3D or 2D) is their sensitivity to the presence of metallic material, limiting their application in operated knees.

  14. MRI-three dimensional reconstruction of biliary system in choledochal cyst

    International Nuclear Information System (INIS)

    Kaji, Tatsuru; Takamatsu, Hideo; Noguchi, Hiroyuki; Tahara, Hiroyuki; Fukushige, Takahiko; Kajiya, Hiroshi; Kajiya, Yoshiki

    1995-01-01

    We report a trial of MR cholangiography in children with choledochal cyst. Recently, three-dimensional reconstruction using magnetic resolution imaging of biliary system (MR cholangiography) has been reported as the less-invasive diagnostic method for obstructive lesions of biliary system. Forty-eight cases of choledochal cyst were treated at Kagoshima University Hospital in the past ten years. In 22 of them, intrahepatic duct dilatation was revealed by preoperative or operative cholangiogram. We tried MR cholangiography in nine cases of 22 cases pre- and/or post-operatively. Five cases had MR cholangiography preoperatively. Intrahepatic biliary dilatation was revealed in all of them and intrahepatic biliary stenosis was revealed in two cases. These findings were almost the same as those by preoperative or operative cholangiogram. MR cholangiography was applied on seven cases postoperatively: 3 cases had fine construction of biliary system, because they still had intrahepatic biliary dilatation, and no dilatation was seen in 4 cases, because of good operative results. This method has advantages of less-invasive in children, no need of contrast dye, and fair delineation of biliary system as samely as endoscopic retrograde cholangiography (ERCP) and percutaneous transhepatic cholangiography (PTC). In cases of huge biliary dilatation, MR cholangiography provides more information concerning intrahepatic biliary than ERCP. (author)

  15. 4 T MRI of chondrocalcinosis in combination with three-dimensional CT, radiography, and arthroscopy: a report of three cases

    International Nuclear Information System (INIS)

    Suan, J.C.; Chhem, R.K.; Gati, J.S.; Norley, C.J.; Holdsworth, D.W.

    2005-01-01

    To describe 4 T MRI techniques in imaging chondrocalcinosis within the knee and examine the results together with those demonstrated using three-dimensional (3D) computed tomography, conventional radiography, and arthroscopy. From a larger clinical imaging study of early osteoarthritis, knee arthroscopy patients were imaged using high-field MRI and high-resolution 3D CT prior to their surgery. Retrospective review of the imaging data diagnosed three patients with chondrocalcinosis. Fat-suppressed 3D spoiled gradient (3D SPGR) and two-dimensional fat-suppressed fast spin echo (FSE) imaging was performed at 4 T. The MR images, multi-planar reformatted CT (MPR-CT) and maximum intensity projection CT (MIP-CT) images, and radiographs were examined by a musculoskeletal radiologist for the presence and location of chondrocalcinosis. The findings from arthroscopy were also included. MRI showed 16 sites of punctate hypointense regions from 18 articular surfaces and five of six menisci with similar signal characteristics. Both meniscal chondrocalcinosis and meniscal tears were clearly visible using the 3D SPGR sequence. Only three sites were demonstrated to have calcification using MPR-CT and MIP-CT revealed an additional three. In articular cartilage surfaces showing surface disruption, arthroscopy demonstrated 11 sites with crystal deposition. Arthroscopy also revealed five menisci with calcification present. Our preliminary findings suggest that imaging chondrocalcinosis using spoiled gradient 4 T MRI is superior and complementary to the other imaging modalities in the detection of crystal deposition in both articular cartilage and menisci. (orig.)

  16. 4 T MRI of chondrocalcinosis in combination with three-dimensional CT, radiography, and arthroscopy: a report of three cases

    Energy Technology Data Exchange (ETDEWEB)

    Suan, J.C.; Chhem, R.K.; Gati, J.S.; Norley, C.J.; Holdsworth, D.W. [Robarts Research Institute, Imaging Research Laboratories, London, Ontario (Canada)

    2005-11-01

    To describe 4 T MRI techniques in imaging chondrocalcinosis within the knee and examine the results together with those demonstrated using three-dimensional (3D) computed tomography, conventional radiography, and arthroscopy. From a larger clinical imaging study of early osteoarthritis, knee arthroscopy patients were imaged using high-field MRI and high-resolution 3D CT prior to their surgery. Retrospective review of the imaging data diagnosed three patients with chondrocalcinosis. Fat-suppressed 3D spoiled gradient (3D SPGR) and two-dimensional fat-suppressed fast spin echo (FSE) imaging was performed at 4 T. The MR images, multi-planar reformatted CT (MPR-CT) and maximum intensity projection CT (MIP-CT) images, and radiographs were examined by a musculoskeletal radiologist for the presence and location of chondrocalcinosis. The findings from arthroscopy were also included. MRI showed 16 sites of punctate hypointense regions from 18 articular surfaces and five of six menisci with similar signal characteristics. Both meniscal chondrocalcinosis and meniscal tears were clearly visible using the 3D SPGR sequence. Only three sites were demonstrated to have calcification using MPR-CT and MIP-CT revealed an additional three. In articular cartilage surfaces showing surface disruption, arthroscopy demonstrated 11 sites with crystal deposition. Arthroscopy also revealed five menisci with calcification present. Our preliminary findings suggest that imaging chondrocalcinosis using spoiled gradient 4 T MRI is superior and complementary to the other imaging modalities in the detection of crystal deposition in both articular cartilage and menisci. (orig.)

  17. Investigation of hydrocephalus with three-dimensional constructive interference in steady state MRI

    International Nuclear Information System (INIS)

    Kurihara, N.; National Sendai Hospital; Takahashi, S.; Higano, S.; Furuta, S.; Umetsu, A.; Tamura, H.; Research Inst. of Brain and Blood Vessels, Akita; Jokura, H.

    2000-01-01

    We report four patients with various types of hydrocephalus in whom constructive interference in steady state (CISS) MRI disclosed the cause of the hydrocephalus. The imaging clearly delineated an abnormal contour of the ventricular system and intraventricular septa, essential information for surgical planning, including endoscopic surgery. Postoperative CISS images were useful for showing not only regression of hydrocephalus but also the patency of small fenestrations. (orig.)

  18. Three-Dimensional Assessment of Temporomandibular Joint Using MRI-CBCT Image Registration.

    Directory of Open Access Journals (Sweden)

    Mohammed A Q Al-Saleh

    Full Text Available To introduce a new approach to reconstruct a 3D model of the TMJ using magnetic resonance imaging (MRI and cone-beam computed tomography (CBCT registered images, and to evaluate the intra-examiner reproducibility values of reconstructing the 3D models of the TMJ.MRI and CBCT images of five patients (10 TMJs were obtained. Multiple MRIs and CBCT images were registered using a mutual information based algorithm. The articular disc, condylar head and glenoid fossa were segmented at two different occasions, at least one-week apart, by one investigator, and 3D models were reconstructed. Differences between the segmentation at two occasions were automatically measured using the surface contours (Average Perpendicular Distance and the volume overlap (Dice Similarity Index of the 3D models. Descriptive analysis of the changes at 2 occasions, including means and standard deviation (SD were reported to describe the intra-examiner reproducibility.The automatic segmentation of the condyle revealed maximum distance change of 1.9±0.93 mm, similarity index of 98% and root mean squared distance of 0.1±0.08 mm, and the glenoid fossa revealed maximum distance change of 2±0.52 mm, similarity index of 96% and root mean squared distance of 0.2±0.04 mm. The manual segmentation of the articular disc revealed maximum distance change of 3.6±0.32 mm, similarity index of 80% and root mean squared distance of 0.3±0.1 mm.The MRI-CBCT registration provides a reliable tool to reconstruct 3D models of the TMJ's soft and hard tissues, allows quantification of the articular disc morphology and position changes with associated differences of the condylar head and glenoid fossa, and facilitates measuring tissue changes over time.

  19. Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

    Energy Technology Data Exchange (ETDEWEB)

    Hosoya, T.; Adachi, M.; Sugai, Y. [Dept. of Radiology, Yamagata University School of Medicine (Japan); Yamaguchi, K.; Yamaguchi, K. [Dept. of Ophthalmology, Yamagata University School of Medicine (Japan); Kato, T. [3. Dept. of Internal Medicine, Yamagata University School of Medicine (Japan)

    2001-04-01

    We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

  20. Abducens nerve enhancement demonstrated by multiplanar reconstruction of contrast-enhanced three-dimensional MRI

    International Nuclear Information System (INIS)

    Hosoya, T.; Adachi, M.; Sugai, Y.; Yamaguchi, K.; Yamaguchi, K.; Kato, T.

    2001-01-01

    We describe contrast enhancement of the cisternal portion of the abducens nerve and discuss its clinical significance. We examined 67 patients with ophthalmoplegia using contrast-enhanced 3-dimensional (3D) MRI with multiplanar reconstruction along the nerves and found 16 patients (ten men, six women), aged 10-73 years (mean 34.4 years), with contrast enhancement of the abducens nerve. Of the 36 patients who had an abducens palsy, 14 (39 %) showed contrast enhancement. In the 16 patients, 23 abducens nerves enhanced; 13 were symptomatic and 10 asymptomatic at the time. The causes were disseminated tumour (1), an inflammatory process (3), trauma (2), ischaemia (2) and autoimmune diseases (8), such as the Miller Fisher syndrome, acute ophthalmoparesis, polyneuropathy and multiple sclerosis. Abducens and/or oculomotor nerve enhancement was the only abnormality on MRI in the patients with traumatic or ischaemic neuropathy or autoimmune diseases. There were 14 patients who recovered fully within 1-6 months after treatment, and resolution of the enhancement correlated well with recovery. (orig.)

  1. Diagnosis of nerve root compromise of the lumbar spine: Evaluation of the performance of three-dimensional isotropic T2-weighted turbo spin-echo SPACE sequence at 3T

    Energy Technology Data Exchange (ETDEWEB)

    Sung, Jin Kyeong; Jee, Won Hee; Jung, Joon Yong; Jang, Jin Hee; Kim, Jin Sung; Kim, Young Hoon; Ha, Kee Yong [Seoul St. Mary' s Hospital, College of Medicine, The Catholic University of Korea, Seoul (Korea, Republic of)

    2017-01-15

    To explore the performance of three-dimensional (3D) isotropic T2-weighted turbo spin-echo (TSE) sampling perfection with application optimized contrasts using different flip angle evolution (SPACE) sequence on a 3T system, for the evaluation of nerve root compromise by disc herniation or stenosis from central to extraforaminal location of the lumbar spine, when used alone or in combination with conventional two-dimensional (2D) TSE sequence. Thirty-seven patients who had undergone 3T spine MRI including 2D and 3D sequences, and had subsequent spine surgery for nerve root compromise at a total of 39 nerve levels, were analyzed. A total of 78 nerve roots (48 symptomatic and 30 asymptomatic sites) were graded (0 to 3) using different MRI sets of 2D, 3D (axial plus sagittal), 3D (all planes), and combination of 2D and 3D sequences, with respect to the nerve root compromise caused by posterior disc herniations, lateral recess stenoses, neural foraminal stenoses, or extraforaminal disc herniations; grading was done independently by two readers. Diagnostic performance was compared between different imaging sets using the receiver operating characteristics (ROC) curve analysis. There were no statistically significant differences (p = 0.203 to > 0.999) in the ROC curve area between the imaging sets for both readers 1 and 2, except for combined 2D and 3D (0.843) vs. 2D (0.802) for reader 1 (p = 0.035), and combined 2D and 3D (0.820) vs. 3D including all planes (0.765) for reader 2 (p = 0.049). The performance of 3D isotropic T2-weighted TSE sequence of the lumbar spine, whether axial plus sagittal images, or all planes of images, was not significantly different from that of 2D TSE sequences, for the evaluation of nerve root compromise of the lumbar spine. Combining 2D and 3D might possibly improve the diagnostic accuracy compared with either one.

  2. Three-dimensional cine MRI in free-breathing infants and children with congenital heart disease

    Energy Technology Data Exchange (ETDEWEB)

    Seeger, Achim; Fenchel, Michael C.; Kramer, Ulrich; Bretschneider, Christiane; Doering, Joerg; Claussen, Claus D.; Miller, Stephan [University of Tuebingen (Germany). Department of Diagnostic and Interventional Radiology; Greil, Gerald F. [St. Thomas Hospital, Division of Imaging Sciences, King' s College London (United Kingdom); Martirosian, Petros [University of Tuebingen, Section of Experimental Radiology, Tuebingen (Germany); Sieverding, Ludger [University of Tuebingen, Department of Pediatric Cardiology, Tuebingen (Germany)

    2009-12-15

    Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease. (orig.)

  3. Three-dimensional cine MRI in free-breathing infants and children with congenital heart disease

    International Nuclear Information System (INIS)

    Seeger, Achim; Fenchel, Michael C.; Kramer, Ulrich; Bretschneider, Christiane; Doering, Joerg; Claussen, Claus D.; Miller, Stephan; Martirosian, Petros; Sieverding, Ludger

    2009-01-01

    Patients with congenital heart disease frequently have complex cardiac and vascular malformations requiring detailed non-invasive diagnostic evaluation including functional parameters. To evaluate the morphological and functional information provided by a novel 3-D cine steady-state free-precession (SSFP) sequence. Twenty consecutive children (mean age 2.2 years, nine boys) were examined using a 1.5-T MR system including 2-D cine gradient-recalled-echo sequences, static 3-D SSFP and 3-D cine SSFP sequences. Measurement of ventricular structures and volumes showed close agreement between the 3-D cine SSFP sequence and the 2-D cine gradient-recalled-echo and static 3-D SSFP sequences (left ventricular volumes mean difference 1.0-1.9 ml and 8.8-11.4%, respectively; right ventricular volumes 1.7-2.1 ml and 9.9-16.9%, respectively). No systematic bias was observed. 3-D cine MRI provides anatomic as well as functional information with sufficient spatial and temporal resolution in free-breathing infants with congenital heart disease. (orig.)

  4. Comparing three-dimensional serial optical coherence tomography histology to MRI imaging in the entire mouse brain

    Science.gov (United States)

    Castonguay, Alexandre; Lefebvre, Joël; Pouliot, Philippe; Lesage, Frédéric

    2018-01-01

    An automated serial histology setup combining optical coherence tomography (OCT) imaging with vibratome sectioning was used to image eight wild type mouse brains. The datasets resulted in thousands of volumetric tiles resolved at a voxel size of (4.9×4.9×6.5) μm3 stitched back together to give a three-dimensional map of the brain from which a template OCT brain was obtained. To assess deformation caused by tissue sectioning, reconstruction algorithms, and fixation, OCT datasets were compared to both in vivo and ex vivo magnetic resonance imaging (MRI) imaging. The OCT brain template yielded a highly detailed map of the brain structure, with a high contrast in white matter fiber bundles and was highly resemblant to the in vivo MRI template. Brain labeling using the Allen brain framework showed little variation in regional brain volume among imaging modalities with no statistical differences. The high correspondence between the OCT template brain and its in vivo counterpart demonstrates the potential of whole brain histology to validate in vivo imaging.

  5. Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes.

    Science.gov (United States)

    Bjerre, Troels; Crijns, Sjoerd; af Rosenschöld, Per Munck; Aznar, Marianne; Specht, Lena; Larsen, Rasmus; Keall, Paul

    2013-07-21

    The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path. For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm for a translation of 39.9 mm. We have demonstrated how interleaved acquired, orthogonal cine-MRI planes can be used for online tracking of soft-tissue target volumes.

  6. A new background distribution-based active contour model for three-dimensional lesion segmentation in breast DCE-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Hui; Liu, Yiping; Qiu, Tianshuang [Department of Biomedical Engineering, Dalian University of Technology, Dalian 116024 (China); Zhao, Zuowei, E-mail: liuhui@dlut.edu.cn [Second Affiliated Hospital, Dalian Medical University, Dalian 116027 (China); Zhang, Lina [Department of Radiology, First Affiliated Hospital, Dalian Medical University, Dalian 116027 (China)

    2014-08-15

    Purpose: To develop and evaluate a computerized semiautomatic segmentation method for accurate extraction of three-dimensional lesions from dynamic contrast-enhanced magnetic resonance images (DCE-MRIs) of the breast. Methods: The authors propose a new background distribution-based active contour model using level set (BDACMLS) to segment lesions in breast DCE-MRIs. The method starts with manual selection of a region of interest (ROI) that contains the entire lesion in a single slice where the lesion is enhanced. Then the lesion volume from the volume data of interest, which is captured automatically, is separated. The core idea of BDACMLS is a new signed pressure function which is based solely on the intensity distribution combined with pathophysiological basis. To compare the algorithm results, two experienced radiologists delineated all lesions jointly to obtain the ground truth. In addition, results generated by other different methods based on level set (LS) are also compared with the authors’ method. Finally, the performance of the proposed method is evaluated by several region-based metrics such as the overlap ratio. Results: Forty-two studies with 46 lesions that contain 29 benign and 17 malignant lesions are evaluated. The dataset includes various typical pathologies of the breast such as invasive ductal carcinoma, ductal carcinomain situ, scar carcinoma, phyllodes tumor, breast cysts, fibroadenoma, etc. The overlap ratio for BDACMLS with respect to manual segmentation is 79.55% ± 12.60% (mean ± s.d.). Conclusions: A new active contour model method has been developed and shown to successfully segment breast DCE-MRI three-dimensional lesions. The results from this model correspond more closely to manual segmentation, solve the weak-edge-passed problem, and improve the robustness in segmenting different lesions.

  7. Three-dimensional MRI-linac intra-fraction guidance using multiple orthogonal cine-MRI planes

    DEFF Research Database (Denmark)

    Bjerre, Troels; Crijns, Sjoerd; Rosenschöld, Per Munck af

    2013-01-01

    The introduction of integrated MRI-radiation therapy systems will offer live intra-fraction imaging. We propose a feasible low-latency multi-plane MRI-linac guidance strategy. In this work we demonstrate how interleaved acquired, orthogonal cine-MRI planes can be used for low-latency tracking...... of the 3D trajectory of a soft-tissue target structure. The proposed strategy relies on acquiring a pre-treatment 3D breath-hold scan, extracting a 3D target template and performing template matching between this 3D template and pairs of orthogonal 2D cine-MRI planes intersecting the target motion path....... For a 60 s free-breathing series of orthogonal cine-MRI planes, we demonstrate that the method was capable of accurately tracking the respiration related 3D motion of the left kidney. Quantitative evaluation of the method using a dataset designed for this purpose revealed a translational error of 1.15 mm...

  8. Evaluation of shoulder pathology: three-dimensional enhanced T1 high-resolution isotropic volume excitation MR vs two-dimensional fast spin echo T2 fat saturation MR.

    Science.gov (United States)

    Park, H J; Lee, S Y; Kim, M S; Choi, S H; Chung, E C; Kook, S H; Kim, E

    2015-03-01

    To evaluate the diagnostic accuracy of three-dimensional (3D) enhanced T1 high-resolution isotropic volume excitation (eTHRIVE) shoulder MR for the detection of rotator cuff tears, labral lesions and calcific tendonitis of the rotator cuff in comparison with two-dimensional (2D) fast spin echo T2 fat saturation (FS) MR. This retrospective study included 73 patients who underwent shoulder MRI using the eTHRIVE technique. Shoulder MR images were interpreted separately by two radiologists. They evaluated anatomic identification and image quality of the shoulder joint on routine MRI sequences (axial and oblique coronal T2 FS images) and compared them with the reformatted eTHRIVE images. The images were scored on a four-point scale (0, poor; 1, questionable; 2, adequate; 3, excellent) according to the degree of homogeneous and sufficient fat saturation to penetrate bone and soft tissue, visualization of the glenoid labrum and distinction of the supraspinatus tendon (SST). The diagnostic accuracy of eTHRIVE images compared with routine MRI sequences was evaluated in the setting of rotator cuff tears, glenoid labral injuries and calcific tendonitis of the SST. Fat saturation scores for eTHRIVE were significantly higher than those of the T2 FS for both radiologists. The sensitivity and accuracy of the T2 FS in diagnosing rotor cuff tears were >90%, whereas sensitivity and accuracy of the eTHRIVE method were significantly lower. The sensitivity, specificity and accuracy of both images in diagnosing labral injuries and calcific tendonitis were similar and showed no significant differences. The specificity of both images for the diagnosis of labral injuries and calcific tendonitis was higher than the sensitivities. The accuracy of 3D eTHRIVE imaging was comparable to that of 2D FSE T2 FS for the diagnosis of glenoid labral injury and calcific tendonitis of SST. The 3D eTHRIVE technique was superior to 2D FSE T2 FS in terms of fat saturation. Overall, 3D eTHRIVE was inferior

  9. Three-dimensional black-blood contrast-enhanced MRI improves detection of intraluminal thrombi in patients with acute ischaemic stroke.

    Science.gov (United States)

    Jang, Won; Kwak, Hyo Sung; Chung, Gyung Ho; Hwang, Seung Bae

    2018-03-19

    This study evaluated the utility of three-dimensional (3D), black-blood (BB), contrast-enhanced, magnetic resonance imaging (MRI) for the detection of intraluminal thrombi in acute stroke patients. Forty-seven patients with acute stroke involving the anterior circulation underwent MRI examination within 6 h of clinical onset. Cerebral angiography was used as the reference standard. In a blinded manner, two neuroradiologists interpreted the following three data sets: (1) diffusion-weighted imaging (DWI) + 3D BB contrast-enhanced MRI; (2) DWI + susceptibility weighted imaging (SWI); (3) DWI + 3D BB contrast-enhanced MRI + SWI. Of these patients, 47 had clots in the middle cerebral artery and four had clots in the anterior cerebral artery. For both observers, the area under the curve (Az) for data sets 1 and 3, which included 3D BB contrast-enhanced MRI, was significantly greater than it was for data set 2, which did not include 3D BB contrast-enhanced MR imaging (observer 1, 0.988 vs 0.904, p = 0.001; observer 2, 0.988 vs 0.894, p = 0.000). Three-dimensional BB contrast-enhanced MRI improves detection of intraluminal thrombi compared to conventional MRI methods in patients with acute ischaemic stroke. • BB contrast-enhanced MRI helps clinicians to assess the intraluminal clot • BB contrast-enhanced MRI improves detection of intraluminal thrombi • BB contrast-enhanced MRI for clot detection has a higher sensitivity.

  10. Three-dimensional anisotropy contrast MRI and functional MRI of the human brain. Clinical application to assess pyramidal tract in patients with brain tumor and infarction

    International Nuclear Information System (INIS)

    Morikawa, Minoru; Kaminogo, Makio; Ishimaru, Hideki; Nakashima, Kazuaki; Kitagawa, Naoki; Ochi, Makoto; Hayashi, Kuniaki; Shibata, Shobu; Kabasawa, Hiroyuki

    2001-01-01

    We describe and evaluate the findings of three-dimensional anisotropy contrast MR axonography (3DAC MRX) and functional MRI (fMRI) in brain tumor and infarction. We obtained diffusion-weighted images (DWI) in 28 patients including 23 brain tumors and 15 acute infarctions located in or near pyramidal tract. Three anisotropic DWIs were transformed into graduations color-coded as red, green and blue, and then composed to form a combined color 3DAC MRX. We also performed functional MRI in 7 of the 28 patients and compared with cortical mapping of 3DAC MRX. 3DAC MRX with 23 brain tumors showed that the ipsilateral pyramidal tract was either discontinuous due to impaired anisotropy (n=8) or compressed due to mass effect (n=15). In 10 patients of acute infarction with motor impairment, pyramidal tract involvement was visually more conspicuous on 3DAC MRX compared to standard DWI. On functional MRI, hand motor activation was observed between blue vertical directional colors of pre- and post central gyrus. In conclusion, 3DAC MRX is a new noninvasive approach for visualization of the white matter neuronal tract and provides the information concerning pyramidal tract involvement. (author)

  11. Three-dimensional ultrashort echo time MRI and Short T2 images generated from subtraction for determination of tumor burden in lung cancer: Preclinical investigation in transgenic mice.

    Science.gov (United States)

    Müller, Andreas; Jagoda, Philippe; Fries, Peter; Gräber, Stefan; Bals, Robert; Buecker, Arno; Jungnickel, Christopher; Beisswenger, Christoph

    2018-02-01

    To investigate the potential of 3D ultrashort echo time MRI and short T 2 images generated by subtraction for determination of total tumor burden in lung cancer. As an animal model of spontaneously developing non-small cell lung cancer, the K-rasLA1 transgenic mouse was used. Three-dimensional MR imaging was performed with radial k-space acquisition and echo times of 20 µs and 1 ms. For investigation of the short T 2 component in the recorded signal, subtraction images were generated from these data sets and used for consensus identification of tumors. Next, manual segmentation was performed on all MR images by two independent investigators. MRI data were compared with the results from histologic investigations and among the investigators. Tumor number and total tumor burden from imaging experiments correlated strongly with the results of histologic investigations. Intra- and interuser comparison showed highest correlations between the individual measurements for ultra-short TE MRI. Three-dimensional MRI protocols facilitate accurate tumor identification in mice harboring lung tumors. Ultrashort TE MRI is the superior imaging strategy when investigating lung tumors of miscellaneous size with 3D MR imaging strategies. Magn Reson Med 79:1052-1060, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  12. MRI and three dimensional ultrasonography in the assessment of pulmonary hypoplasia in fetuses with urinary tract anomalies

    Directory of Open Access Journals (Sweden)

    Mariam Raafat

    2016-12-01

    Conclusion: There is a good concordance between 3D-US and MRI in the evaluation of PH in fetuses with UTM. MRI could be reserved for borderline cases of pulmonary hypoplasia and the difficult diagnostic situations.

  13. High-spatial-resolution isotropic three-dimensional fast-recovery fast spin-echo magnetic resonance dacryocystography combined with topical administration of sterile saline solution

    International Nuclear Information System (INIS)

    Jing, Zhang; Lang, Chen; Qiu-Xia, Wang; Rong, Liu; Xin, Luo; Wen-Zhen, Zhu; Li-Ming, Xia; Jian-Pin, Qi; He, Wang

    2013-01-01

    Objective: This study aims to investigate the clinical performance of three-dimensional (3D) fast-recovery fast spin-echo (FRFSE) magnetic resonance dacryocystography (MRD) with topical administration of sterile saline solution for the assessment of the lacrimal drainage system (LDS). Methods: A total of 13 healthy volunteers underwent both 3D-FRFSE MRD and two-dimensional (2D)-impulse recovery (IR)-single-shot fast spin-echo (SSFSE) MRD after topical administration of sterile saline solution, and 31 patients affected by primary LDS outflow impairment or postsurgical recurrent epiphora underwent 3D-FRFSE MRD and conventional T1- and T2-weighted sequences. All patients underwent lacrimal endoscopy or surgery, which served as a standard of reference for confirming the MRD findings. Results: 3D-FRFSE MRD detected more visualized superior and inferior canaliculi and nasolacrimal duct than 2D-IR-SSFSE MRD. Compared with 2D-IR-SSFSE MRD, 3D-FRFSE MRD showed more visualized segments per LDS, although the difference was not statistically significant. Significant improvements in the inferior canaliculus and nasolacrimal duct visibility grades were achieved using 3D-FRFSE MRD. 3D-FRFSE MRD had 100% sensitivity and 63.6% specificity for detecting LDS obstruction. In 51 out of the 62 LDSs that were assessed, a 90% agreement was noted between the findings of 3D-FRFSE MRD and lacrimal endoscopy in detecting the obstruction level. Conclusion: 3D-FRFSE MRD combined with topical administration of sterile saline solution is a simple and noninvasive method of obtaining detailed morphological and functional information on the LDS. Overall, 3D-FRFSE MRD could be used as a reliable diagnostic method in many patients with epiphora prior to surgery

  14. Three-dimensional dynamic contrast-enhanced MRI for the accurate, extensive quantification of microvascular permeability in atherosclerotic plaques

    NARCIS (Netherlands)

    Calcagno, Claudia; Lobatto, Mark E.; Dyvorne, Hadrien; Robson, Philip M.; Millon, Antoine; Senders, Max L.; Lairez, Olivier; Ramachandran, Sarayu; Coolen, Bram F.; Black, Alexandra; Mulder, Willem J. M.; Fayad, Zahi A.

    2015-01-01

    Atherosclerotic plaques that cause stroke and myocardial infarction are characterized by increased microvascular permeability and inflammation. Dynamic contrast-enhanced MRI (DCE-MRI) has been proposed as a method to quantify vessel wall microvascular permeability in vivo. Until now, most DCE-MRI

  15. Three Dimensional Parametric Analyses of Stress Concentration Factor and Its Mitigation in Isotropic and Orthotropic Plate with Central Circular Hole Under Axial In-Plane Loading

    Science.gov (United States)

    Nagpal, Shubhrata; Jain, Nitin Kumar; Sanyal, Shubhashis

    2016-01-01

    The problem of finding the stress concentration factor of a loaded rectangular plate has offered considerably analytical difficulty. The present work focused on understanding of behavior of isotropic and orthotropic plate subjected to static in-plane loading using finite element method. The complete plate model configuration has been analyzed using finite element method based software ANSYS. In the present work two parameters: thickness to width of plate (T/A) and diameter of hole to width of plate (D/A) have been varied for analysis of stress concentration factor (SCF) and its mitigation. Plates of five different materials have been considered for complete analysis to find out the sensitivity of stress concentration factor. The D/A ratio varied from 0.1 to 0.7 for analysis of SCF and varied from 0.1 to 0.5 for analyzing the mitigation of SCF. 0.01, 0.05 and 0.1 are considered as T/A ratio for all the cases. The results are presented in graphical form and discussed. The mitigation in SCF reported is very encouraging. The SCF is more sensitive to D/A ratio as compared to T/A.

  16. A SiPM-based isotropic-3D PET detector X'tal cube with a three-dimensional array of 1 mm{sup 3} crystals

    Energy Technology Data Exchange (ETDEWEB)

    Yamaya, Taiga; Mitsuhashi, Takayuki; Inadama, Naoko; Nishikido, Fumihiko; Yoshida, Eiji; Murayama, Hideo [Molecular Imaging Center, National Institute of Radiological Sciences, 4-9-1 Anagawa, Inage-ku, Chiba 263-8555 (Japan); Matsumoto, Takahiro; Kawai, Hideyuki; Suga, Mikio [Chiba University, 1-33 Yayoicho, Inage-ku, Chiba 263-8522 (Japan); Watanabe, Mitsuo, E-mail: taiga@nirs.go.jp [Central Research Laboratory, Hamamatsu Photonics K.K., 5000 Hirakuchi, Hamakita-ku, Hamamatsu 434-8601 (Japan)

    2011-11-07

    We are developing a novel, general purpose isotropic-3D PET detector X'tal cube which has high spatial resolution in all three dimensions. The research challenge for this detector is implementing effective detection of scintillation photons by covering six faces of a segmented crystal block with silicon photomultipliers (SiPMs). In this paper, we developed the second prototype of the X'tal cube for a proof-of-concept. We aimed at realizing an ultimate detector with 1.0 mm{sup 3} cubic crystals, in contrast to our previous development using 3.0 mm{sup 3} cubic crystals. The crystal block was composed of a 16 x 16 x 16 array of lutetium gadolinium oxyorthosilicate (LGSO) crystals 0.993 x 0.993 x 0.993 mm{sup 3} in size. The crystals were optically glued together without inserting any reflector inside and 96 multi-pixel photon counters (MPPCs, S10931-50P, i.e. six faces each with a 4 x 4 array of MPPCs), each having a sensitive area of 3.0 x 3.0 mm{sup 2}, were optically coupled to the surfaces of the crystal block. Almost all 4096 crystals were identified through Anger-type calculation due to the finely adjusted reflector sheets inserted between the crystal block and light guides. The reflector sheets, which formed a belt of 0.5 mm width, were placed to cover half of the crystals of the second rows from the edges in order to improve identification performance of the crystals near the edges. Energy resolution of 12.7% was obtained at 511 keV with almost uniform light output for all crystal segments thanks to the effective detection of the scintillation photons.

  17. Effects of emotional valence and three-dimensionality of visual stimuli on brain activation: an fMRI study.

    Science.gov (United States)

    Dores, A R; Almeida, I; Barbosa, F; Castelo-Branco, M; Monteiro, L; Reis, M; de Sousa, L; Caldas, A Castro

    2013-01-01

    Examining changes in brain activation linked with emotion-inducing stimuli is essential to the study of emotions. Due to the ecological potential of techniques such as virtual reality (VR), inspection of whether brain activation in response to emotional stimuli can be modulated by the three-dimensional (3D) properties of the images is important. The current study sought to test whether the activation of brain areas involved in the emotional processing of scenarios of different valences can be modulated by 3D. Therefore, the focus was made on the interaction effect between emotion-inducing stimuli of different emotional valences (pleasant, unpleasant and neutral valences) and visualization types (2D, 3D). However, main effects were also analyzed. The effect of emotional valence and visualization types and their interaction were analyzed through a 3 × 2 repeated measures ANOVA. Post-hoc t-tests were performed under a ROI-analysis approach. The results show increased brain activation for the 3D affective-inducing stimuli in comparison with the same stimuli in 2D scenarios, mostly in cortical and subcortical regions that are related to emotional processing, in addition to visual processing regions. This study has the potential of clarify brain mechanisms involved in the processing of emotional stimuli (scenarios' valence) and their interaction with three-dimensionality.

  18. Extended endoscopic endonasal surgery using three-dimensional endoscopy in the intra-operative MRI suite for supra-diaphragmatic ectopic pituitary adenoma.

    Science.gov (United States)

    Fuminari, Komatsu; Hideki, Atsumi; Manabu, Osakabe; Mitsunori, Matsumae

    2015-01-01

    We describe a supra-diaphragmatic ectopic pituitary adenoma that was safely removed using the extended endoscopic endonasal approach, and discuss the value of three-dimensional (3D) endoscopy and intra-operative magnetic resonance imaging (MRI) to this type of procedure. A 61-year-old-man with bitemporal hemianopsia was referred to our hospital, where MRI revealed an enhanced suprasellar tumor compressing the optic chiasma. The tumor extended on the planum sphenoidale and partially encased the right internal carotid artery. An endocrinological assessment indicated normal pituitary function. The extended endoscopic endonasal approach was taken using a 3D endoscope in the intraoperative MRI suite. The tumor was located above the diaphragma sellae and separated from the normal pituitary gland. The pathological findings indicated non-functioning pituitary adenoma and thus the tumor was diagnosed as a supra-diaphragmatic ectopic pituitary adenoma. Intra-operative MRI provided useful information to minimize dural opening and the supra-diaphragmatic ectopic pituitary adenoma was removed from the complex neurovascular structure via the extended endoscopic endonasal approach under 3D endoscopic guidance in the intra-operative suite. Safe and effective removal of a supra-diaphragmatic ectopic pituitary adenoma was accomplished via the extended endoscopic endonasal approach with visual information provided by 3D endoscopy and intra-operative MRI.

  19. Three-dimensional quantification of vorticity and helicity from 3D cine PC-MRI using finite-element interpolations.

    Science.gov (United States)

    Sotelo, Julio; Urbina, Jesús; Valverde, Israel; Mura, Joaquín; Tejos, Cristián; Irarrazaval, Pablo; Andia, Marcelo E; Hurtado, Daniel E; Uribe, Sergio

    2018-01-01

    We propose a 3D finite-element method for the quantification of vorticity and helicity density from 3D cine phase-contrast (PC) MRI. By using a 3D finite-element method, we seamlessly estimate velocity gradients in 3D. The robustness and convergence were analyzed using a combined Poiseuille and Lamb-Ossen equation. A computational fluid dynamics simulation was used to compared our method with others available in the literature. Additionally, we computed 3D maps for different 3D cine PC-MRI data sets: phantom without and with coarctation (18 healthy volunteers and 3 patients). We found a good agreement between our method and both the analytical solution of the combined Poiseuille and Lamb-Ossen. The computational fluid dynamics results showed that our method outperforms current approaches to estimate vorticity and helicity values. In the in silico model, we observed that for a tetrahedral element of 2 mm of characteristic length, we underestimated the vorticity in less than 5% with respect to the analytical solution. In patients, we found higher values of helicity density in comparison to healthy volunteers, associated with vortices in the lumen of the vessels. We proposed a novel method that provides entire 3D vorticity and helicity density maps, avoiding the used of reformatted 2D planes from 3D cine PC-MRI. Magn Reson Med 79:541-553, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Evaluation of renal artery and renal masses using enhanced dynamic MRI. Three-dimensional volumetric interpolated breath-hold examination

    International Nuclear Information System (INIS)

    Ishikawa, Aimi; Kakizaki, Dai; Ito, Naoki; Shindou, Hiroaki; Ozuki, Taizou; Abe, Kimihiko; Sasaki, Kazuyoshi; Katsuyama, Hiroaki

    2003-01-01

    The purpose of this study was to evaluate of three-dimensional volumetric interpolated breathhold examination (3D-VIBE) for imaging renal arteries in renal tumor surgery. Twenty four patients to evaluate renal arteries, and 30 patients for staging of renal tumors. For evaluation of renal arteries, the number of renal arteries and secondary branches, and the RA ratio (renal artery diameter per aorta diameter) were investigated. For tumor evaluation, we investigated T factor and presence and condition of tumor capsule, 3D-VIBE was performed with a MAGNETOM Symphony (Siemens, Erlangen, Germany). Before the dynamic study, we measured renal artery acquisition time with 1 ml of contrast material (Gd-DTPA) and 20 ml of physiological saline solution injected into a hand vein at a rate of 3 ml/sec using an automatic injector. The first phase was set for arrival of the Gd-DTPA at the renal artery, the 2nd for 40 sec after the 1st phase, and the 3rd 180 sec after injection. Then we started scanning with 19 ml of Gd-DTPA and 20 ml of physiological saline solution. Maximum intensity projection (MIP) and multiplanar reconstruction (MFR) were reconstructed by the image data set. All renal arteries were correctly counted In one case, a branch of the superior mesenteric artery (SMA) was mistaken for a renal artery, but correctly identified using a stereo view. The rate of depiction of secondary branches was 86% compared with RA ratio which was significantly smaller than on aortic angiography (p<0.05). The findings for 5 tumors were confirmed by CT, but differed pathologically. We believe 3D-VIBE is useful dynamic CT for evaluation of renal arteries and preoperative classification of renal tumors. (author)

  1. Three-dimensional MRI Analysis of Femoral Head Remodeling After Reduction in Patients With Developmental Dysplasia of the Hip.

    Science.gov (United States)

    Tsukagoshi, Yuta; Kamada, Hiroshi; Kamegaya, Makoto; Takeuchi, Ryoko; Nakagawa, Shogo; Tomaru, Yohei; Tanaka, Kenta; Onishi, Mio; Nishino, Tomofumi; Yamazaki, Masashi

    2018-05-02

    Previous reports on patients with developmental dysplasia of the hip (DDH) showed that the prereduced femoral head was notably smaller and more nonspherical than the intact head, with growth failure observed at the proximal posteromedial area. We evaluated the shape of the femoral head cartilage in patients with DDH before and after reduction, with size and sphericity assessed using 3-dimensional (3D) magnetic resonance imaging (MRI). We studied 10 patients with unilateral DDH (all female) who underwent closed reduction. Patients with avascular necrosis of the femoral head on the plain radiograph 1 year after reduction were excluded. 3D MRI was performed before reduction and after reduction, at 2 years of age. 3D-image analysis software was used to reconstruct the multiplanes. After setting the axial, coronal, and sagittal planes in the software (based on the femoral shaft and neck axes), the smallest sphere that included the femoral head cartilage was drawn, the diameter was measured, and the center of the sphere was defined as the femoral head center. We measured the distance between the center and cartilage surface every 30 degrees on the 3 reconstructed planes. Sphericity of the femoral head was calculated using a ratio (the distance divided by each radius) and compared between prereduction and postreduction. The mean patient age was 7±3 and 26±3 months at the first and second MRI, respectively. The mean duration between the reduction and second MRI was 18±3 months. The femoral head diameter was 26.7±1.5 and 26.0±1.6 mm on the diseased and intact sides, respectively (P=0.069). The ratios of the posteromedial area on the axial plane and the proximoposterior area on the sagittal plane after reduction were significantly larger than before reduction (P<0.01). We demonstrated that the size of the reduced femoral head was nearly equal to that of the intact femoral head and that the growth failure area of the head before reduction, in the proximal posteromedial

  2. Qualitative and quantitative assessment of wrist MRI at 3.0T - Comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo

    International Nuclear Information System (INIS)

    Jung, Jee Young; Yoon, Young Cheol; Jung, Jin Young; Choe, Bong-Keun

    2013-01-01

    Background: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated. Purpose: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T. Material and Methods: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed. Results: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial. Conclusion: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for

  3. Qualitative and quantitative assessment of wrist MRI at 3.0T - Comparison between isotropic 3D turbo spin echo and isotropic 3D fast field echo and 2D turbo spin echo

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Jee Young [Dept. of Radiology, Chungang Univ. Hospital, School of Medicine, Chungang Univ. (Korea, Republic of); Yoon, Young Cheol [Dept. of Radiology, Samsung Medical Center, School of Medicine, Sungkyunkwan Univ. (Korea, Republic of)], e-mail: ycyoon@skku.edu; Jung, Jin Young [Dept. of Radiology, Saint Paul' s Hospital, The Catholic Univ. (Korea, Republic of); Choe, Bong-Keun [Dept. of Preventive Medicine, School of Medicine, Kyung Hee Univ., Seoul (Korea, Republic of)

    2013-04-15

    Background: Isotropic three-dimensional (3D) magnetic resonance imaging (MRI) has been applied to various joints. However, comparison for image quality between isotropic 3D MRI and two-dimensional (2D) turbo spin echo (TSE) sequence of the wrist at a 3T MR system has not been investigated. Purpose: To compare the image quality of isotropic 3D MRI including TSE intermediate-weighted (VISTA) sequence and fast field echo (FFE) sequence with 2D TSE intermediate-weighted sequence of the wrist joint at 3.0 T. Material and Methods: MRI was performed in 10 wrists of 10 healthy volunteers with isotropic 3D sequences (VISTA and FFE) and 2D TSE intermediate-weighted sequences at 3.0 T. The signal-to-noise ratio (SNR) was obtained by imaging phantom and noise-only image. Contrast ratios (CRs) were calculated between fluid and cartilage, triangular fibrocartilage complex (TFCC), and the scapholunate ligament. Two radiologists independently assessed the visibility of TFCC, carpal ligaments, cartilage, tendons and nerves with a four-point grading scale. Statistical analysis to compare CRs (one way ANOVA with a Tukey test) and grades of visibility (Kruskal-Wallis test) between three sequences and those for inter-observer agreement (kappa analysis) were performed. Results: The SNR of 2D TSE (46.26) was higher than those of VISTA (23.34) and 3D FFE (19.41). CRs were superior in 2D TSE than VISTA (P = 0.02) for fluid-cartilage and in 2D TSE than 3D FFE (P < 0.01) for fluid-TFCC. The visibility was best in 2D TSE (P < 0.01) for TFCC and in VISTA (P = 0.01) for scapholunate ligament. The visibility was better in 2D TSE and 3D FFE (P 0.04) for cartilage and in VISTA than 3D FFE (P < 0.01) for TFCC. The inter-observer agreement for the visibility of anatomic structures was moderate or substantial. Conclusion: Image quality of 2D TSE was superior to isotropic 3D MR imaging for cartilage, and TFCC. 3D FFE has better visibility for cartilage than VISTA and VISTA has superior visibility for

  4. The role of Gd-enhanced three-dimensional MRI fast low-angle shot (FLASH) in the evaluation of symptomatic lumbosacral nerve roots

    Energy Technology Data Exchange (ETDEWEB)

    Kikkawa, Ichiro; Sugimoto, Hideharu; Saita, Kazuo; Ookami, Hitoshi; Nakama, Sueo; Hoshino, Yuichi [Jichi Medical School, Minamikawachi, Tochigi (Japan)

    2001-07-01

    In the field of lumbar spine disorders, three-dimensional (3-D) magnetic resonance imaging (MRI) can clearly depict a lumbar nerve root from the distal region to the dorsal root ganglion. In this study, we used a gadoliniumdiethylenetriaminepentaacetic acid (Gd-DTPA) enhanced-three-dimensional (3-D) fast low-angle shot (FLASH) sequence when examining lumbosacral disorders. The subjects were 33 patients (14 men and 19 women) in whom lumbosacral neural compression had been diagnosed clinically. Twenty-one patients had lumbar disc herniation, 11 had lumbar spinal stenosis, and 1 had lumbar radiculopathy caused by rheumatoid arthritis. Five subjects with low back pain were also studied as a control group. In all patients and in all 5 of the controls, the dorsal root ganglion of every root was enhanced clearly. There was no root enhancement in the 5 controls. Enhancement of the symptomatic nerve roots, caused by compression, was found in 11 of the 33 patients. All 11 patients had rediculopathy, and muscle weakness was more frequent in patients with enhanced nerve roots than in those without enhancement. There was no enhancement of the cauda equina, even in the patients with cauda syndrome. The enhancement effect may reflect some pathological condition of the compressed nerve root and needs to be studied further. (author)

  5. The role of Gd-enhanced three-dimensional MRI fast low-angle shot (FLASH) in the evaluation of symptomatic lumbosacral nerve roots

    International Nuclear Information System (INIS)

    Kikkawa, Ichiro; Sugimoto, Hideharu; Saita, Kazuo; Ookami, Hitoshi; Nakama, Sueo; Hoshino, Yuichi

    2001-01-01

    In the field of lumbar spine disorders, three-dimensional (3-D) magnetic resonance imaging (MRI) can clearly depict a lumbar nerve root from the distal region to the dorsal root ganglion. In this study, we used a gadoliniumdiethylenetriaminepentaacetic acid (Gd-DTPA) enhanced-three-dimensional (3-D) fast low-angle shot (FLASH) sequence when examining lumbosacral disorders. The subjects were 33 patients (14 men and 19 women) in whom lumbosacral neural compression had been diagnosed clinically. Twenty-one patients had lumbar disc herniation, 11 had lumbar spinal stenosis, and 1 had lumbar radiculopathy caused by rheumatoid arthritis. Five subjects with low back pain were also studied as a control group. In all patients and in all 5 of the controls, the dorsal root ganglion of every root was enhanced clearly. There was no root enhancement in the 5 controls. Enhancement of the symptomatic nerve roots, caused by compression, was found in 11 of the 33 patients. All 11 patients had rediculopathy, and muscle weakness was more frequent in patients with enhanced nerve roots than in those without enhancement. There was no enhancement of the cauda equina, even in the patients with cauda syndrome. The enhancement effect may reflect some pathological condition of the compressed nerve root and needs to be studied further. (author)

  6. Preliminary experience with a novel method of three-dimensional co-registration of prostate cancer digital histology and in vivo multiparametric MRI.

    Science.gov (United States)

    Orczyk, C; Rusinek, H; Rosenkrantz, A B; Mikheev, A; Deng, F-M; Melamed, J; Taneja, S S

    2013-12-01

    To assess a novel method of three-dimensional (3D) co-registration of prostate cancer digital histology and in-vivo multiparametric magnetic resonance imaging (mpMRI) image sets for clinical usefulness. A software platform was developed to achieve 3D co-registration. This software was prospectively applied to three patients who underwent radical prostatectomy. Data comprised in-vivo mpMRI [T2-weighted, dynamic contrast-enhanced weighted images (DCE); apparent diffusion coefficient (ADC)], ex-vivo T2-weighted imaging, 3D-rebuilt pathological specimen, and digital histology. Internal landmarks from zonal anatomy served as reference points for assessing co-registration accuracy and precision. Applying a method of deformable transformation based on 22 internal landmarks, a 1.6 mm accuracy was reached to align T2-weighted images and the 3D-rebuilt pathological specimen, an improvement over rigid transformation of 32% (p = 0.003). The 22 zonal anatomy landmarks were more accurately mapped using deformable transformation than rigid transformation (p = 0.0008). An automatic method based on mutual information, enabled automation of the process and to include perfusion and diffusion MRI images. Evaluation of co-registration accuracy using the volume overlap index (Dice index) met clinically relevant requirements, ranging from 0.81-0.96 for sequences tested. Ex-vivo images of the specimen did not significantly improve co-registration accuracy. This preliminary analysis suggests that deformable transformation based on zonal anatomy landmarks is accurate in the co-registration of mpMRI and histology. Including diffusion and perfusion sequences in the same 3D space as histology is essential further clinical information. The ability to localize cancer in 3D space may improve targeting for image-guided biopsy, focal therapy, and disease quantification in surveillance protocols. Copyright © 2013 The Royal College of Radiologists. Published by Elsevier Ltd. All rights reserved.

  7. Real-time three dimensional CT and MRI to guide interventions for congenital heart disease and acquired pulmonary vein stenosis.

    Science.gov (United States)

    Suntharos, Patcharapong; Setser, Randolph M; Bradley-Skelton, Sharon; Prieto, Lourdes R

    2017-10-01

    To validate the feasibility and spatial accuracy of pre-procedural 3D images to 3D rotational fluoroscopy registration to guide interventional procedures in patients with congenital heart disease and acquired pulmonary vein stenosis. Cardiac interventions in patients with congenital and structural heart disease require complex catheter manipulation. Current technology allows registration of the anatomy obtained from 3D CT and/or MRI to be overlaid onto fluoroscopy. Thirty patients scheduled for interventional procedures from 12/2012 to 8/2015 were prospectively recruited. A C-arm CT using a biplane C-arm system (Artis zee, VC14H, Siemens Healthcare) was acquired to enable 3D3D registration with pre-procedural images. Following successful image fusion, the anatomic landmarks marked in pre-procedural images were overlaid on live fluoroscopy. The accuracy of image registration was determined by measuring the distance between overlay markers and a reference point in the image. The clinical utility of the registration was evaluated as either "High", "Medium" or "None". Seventeen patients with congenital heart disease and 13 with acquired pulmonary vein stenosis were enrolled. Accuracy and benefit of registration were not evaluated in two patients due to suboptimal images. The distance between the marker and the actual anatomical location was 0-2 mm in 18 (64%), 2-4 mm in 3 (11%) and >4 mm in 7 (25%) patients. 3D3D registration was highly beneficial in 18 (64%), intermediate in 3 (11%), and not beneficial in 7 (25%) patients. 3D3D registration can facilitate complex congenital and structural interventions. It may reduce procedure time, radiation and contrast dose.

  8. Three-dimensional vascular mapping of the breast by using contrast-enhanced MRI: association of unilateral increased vascularity with ipsilateral breast cancer.

    Science.gov (United States)

    Orgüç, Şebnem; Başara, Işıl; Coşkun, Teoman; Pekindil, Gökhan

    2012-01-01

    We aimed to retrospectively compare three-dimensional vascular maps of both breasts obtained by dynamic magnetic resonance imaging (MRI) and determine the association of one-sided vascular prominence with ipsilateral breast cancer. MRI was performed using gadolinium in 194 cases. Two readers scored vascular density using maximum intensity projections (MIPs). Dynamic fat-saturated T1-weighted gradientecho MIPs were acquired. Two readers evaluated the MIPs, and vessels greater than 2 mm in diameter and longer than 3 cm were counted. The difference in vessel numbers detected in the two breasts determined the score. A total of 54 patients had malignant lesions (prevalence, 28%), including invasive ductal carcinoma (n=40), invasive mixed ductal-lobular carcinoma (n=5), invasive lobular carcinoma (n=3), ductal carcinoma in situ (n=3), mucinous carcinoma (n=1), medullary carcinoma (n=1), and leukemic metastasis (n=1). In 62 patients, there were benign lesions (fibroadenomas, fibrocysts), and four patients had inflammation (granulomatous mastitis in two patients, breast tuberculosis in two patients). There were 78 normal cases. When a difference of at least two vessels was scored as vascular asymmetry, the sensitivity, specificity, positive likelihood ratio (+LR), and negative (-LR) of unilaterally increased vascularity associated with ipsilateral malignancy were 69%, 92%, 8.72, and 0.34, respectively. When four infection and three post-operative cases with vascular asymmetry were excluded; prevalence, specificity, and +LR increased to 29%, 97%, and 22.8, respectively, with the same sensitivity and -LR. Differences in mean vascularity scores were evaluated with regard to tumor size. T1 and T2 tumors were not significantly different from each other. The mean score of T3 tumors differed significantly from T1 and T2 tumors. MRI vascular mapping is an effective method for determining breast tissue vascularization. Ipsilateral increased vascularity was commonly associated with

  9. Three dimensional strained semiconductors

    Science.gov (United States)

    Voss, Lars; Conway, Adam; Nikolic, Rebecca J.; Leao, Cedric Rocha; Shao, Qinghui

    2016-11-08

    In one embodiment, an apparatus includes a three dimensional structure comprising a semiconductor material, and at least one thin film in contact with at least one exterior surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the three dimensional structure. In another embodiment, a method includes forming a three dimensional structure comprising a semiconductor material, and depositing at least one thin film on at least one surface of the three dimensional structure for inducing a strain in the structure, the thin film being characterized as providing at least one of: an induced strain of at least 0.05%, and an induced strain in at least 5% of a volume of the structure.

  10. In vivo hemodynamic analysis of intracranial aneurysms obtained by magnetic resonance fluid dynamics (MRFD) based on time-resolved three-dimensional phase-contrast MRI

    International Nuclear Information System (INIS)

    Isoda, Haruo; Takeda, Hiroyasu; Yamashita, Shuhei; Takehara, Yasuo; Sakahara, Harumi; Ohkura, Yasuhide; Kosugi, Takashi; Hirano, Masaya; Hiramatsu, Hisaya; Namba, Hiroki; Alley, Marcus T.; Bammer, Roland; Pelc, Norbert J.

    2010-01-01

    Hemodynamics is thought to play a very important role in the initiation, growth, and rupture of intracranial aneurysms. The purpose of our study was to perform in vivo hemodynamic analysis of unruptured intracranial aneurysms of magnetic resonance fluid dynamics using time-resolved three-dimensional phase-contrast MRI (4D-Flow) at 1.5 T and to analyze relationships between hemodynamics and wall shear stress (WSS) and oscillatory shear index (OSI). This study included nine subjects with 14 unruptured aneurysms. 4D-Flow was performed by a 1.5-T magnetic resonance scanner with a head coil. We calculated in vivo streamlines, WSS, and OSI of intracranial aneurysms based on 4D-Flow with our software. We evaluated the number of spiral flows in the aneurysms and compared the differences in WSS or OSI between the vessel and aneurysm and between whole aneurysm and the apex of the spiral flow. 3D streamlines, WSS, and OSI distribution maps in arbitrary direction during the cardiac phase were obtained for all intracranial aneurysms. Twelve aneurysms had one spiral flow each, and two aneurysms had two spiral flows each. The WSS was lower and the OSI was higher in the aneurysm compared to the vessel. The apex of the spiral flow had a lower WSS and higher OSI relative to the whole aneurysm. Each intracranial aneurysm in this study had at least one spiral flow. The WSS was lower and OSI was higher at the apex of the spiral flow than the whole aneurysmal wall. (orig.)

  11. In vivo hemodynamic analysis of intracranial aneurysms obtained by magnetic resonance fluid dynamics (MRFD) based on time-resolved three-dimensional phase-contrast MRI.

    Science.gov (United States)

    Isoda, Haruo; Ohkura, Yasuhide; Kosugi, Takashi; Hirano, Masaya; Takeda, Hiroyasu; Hiramatsu, Hisaya; Yamashita, Shuhei; Takehara, Yasuo; Alley, Marcus T; Bammer, Roland; Pelc, Norbert J; Namba, Hiroki; Sakahara, Harumi

    2010-10-01

    Hemodynamics is thought to play a very important role in the initiation, growth, and rupture of intracranial aneurysms. The purpose of our study was to perform in vivo hemodynamic analysis of unruptured intracranial aneurysms of magnetic resonance fluid dynamics using time-resolved three-dimensional phase-contrast MRI (4D-Flow) at 1.5 T and to analyze relationships between hemodynamics and wall shear stress (WSS) and oscillatory shear index (OSI). This study included nine subjects with 14 unruptured aneurysms. 4D-Flow was performed by a 1.5-T magnetic resonance scanner with a head coil. We calculated in vivo streamlines, WSS, and OSI of intracranial aneurysms based on 4D-Flow with our software. We evaluated the number of spiral flows in the aneurysms and compared the differences in WSS or OSI between the vessel and aneurysm and between whole aneurysm and the apex of the spiral flow. 3D streamlines, WSS, and OSI distribution maps in arbitrary direction during the cardiac phase were obtained for all intracranial aneurysms. Twelve aneurysms had one spiral flow each, and two aneurysms had two spiral flows each. The WSS was lower and the OSI was higher in the aneurysm compared to the vessel. The apex of the spiral flow had a lower WSS and higher OSI relative to the whole aneurysm. Each intracranial aneurysm in this study had at least one spiral flow. The WSS was lower and OSI was higher at the apex of the spiral flow than the whole aneurysmal wall.

  12. Three dimensional canonical transformations

    International Nuclear Information System (INIS)

    Tegmen, A.

    2010-01-01

    A generic construction of canonical transformations is given in three-dimensional phase spaces on which Nambu bracket is imposed. First, the canonical transformations are defined as based on cannonade transformations. Second, it is shown that determination of the generating functions and the transformation itself for given generating function is possible by solving correspondent Pfaffian differential equations. Generating functions of type are introduced and all of them are listed. Infinitesimal canonical transformations are also discussed as the complementary subject. Finally, it is shown that decomposition of canonical transformations is also possible in three-dimensional phase spaces as in the usual two-dimensional ones.

  13. Three-dimensional neuroimaging

    International Nuclear Information System (INIS)

    Toga, A.W.

    1990-01-01

    This book reports on new neuroimaging technologies that are revolutionizing the study of the brain be enabling investigators to visualize its structure and entire pattern of functional activity in three dimensions. The book provides a theoretical and practical explanation of the new science of creating three-dimensional computer images of the brain. The coverage includes a review of the technology and methodology of neuroimaging, the instrumentation and procedures, issues of quantification, analytic protocols, and descriptions of neuroimaging systems. Examples are given to illustrate the use of three-dimensional enuroimaging to quantitate spatial measurements, perform analysis of autoradiographic and histological studies, and study the relationship between brain structure and function

  14. Robust isotropic super-resolution by maximizing a Laplace posterior for MRI volumes

    Science.gov (United States)

    Han, Xian-Hua; Iwamoto, Yutaro; Shiino, Akihiko; Chen, Yen-Wei

    2014-03-01

    Magnetic resonance imaging can only acquire volume data with finite resolution due to various factors. In particular, the resolution in one direction (such as the slice direction) is much lower than others (such as the in-plane direction), yielding un-realistic visualizations. This study explores to reconstruct MRI isotropic resolution volumes from three orthogonal scans. This proposed super- resolution reconstruction is formulated as a maximum a posterior (MAP) problem, which relies on the generation model of the acquired scans from the unknown high-resolution volumes. Generally, the deviation ensemble of the reconstructed high-resolution (HR) volume from the available LR ones in the MAP is represented as a Gaussian distribution, which usually results in some noise and artifacts in the reconstructed HR volume. Therefore, this paper investigates a robust super-resolution by formulating the deviation set as a Laplace distribution, which assumes sparsity in the deviation ensemble based on the possible insight of the appeared large values only around some unexpected regions. In addition, in order to achieve reliable HR MRI volume, we integrates the priors such as bilateral total variation (BTV) and non-local mean (NLM) into the proposed MAP framework for suppressing artifacts and enriching visual detail. We validate the proposed robust SR strategy using MRI mouse data with high-definition resolution in two direction and low-resolution in one direction, which are imaged in three orthogonal scans: axial, coronal and sagittal planes. Experiments verifies that the proposed strategy can achieve much better HR MRI volumes than the conventional MAP method even with very high-magnification factor: 10.

  15. Use of three-dimensional time-resolved phase-contrast magnetic resonance imaging with vastly undersampled isotropic projection reconstruction to assess renal blood flow in a renal cell carcinoma patient treated with sunitinib: a case report.

    Science.gov (United States)

    Takayama, Tatsuya; Takehara, Yasuo; Sugiyama, Masataka; Sugiyama, Takayuki; Ishii, Yasuo; Johnson, Kevin E; Wieben, Oliver; Wakayama, Tetsuya; Sakahara, Harumi; Ozono, Seiichiro

    2014-08-14

    New imaging modalities to assess the efficacy of drugs that have molecular targets remain under development. Here, we describe for the first time the use of time-resolved three-dimensional phase-contrast magnetic resonance imaging to monitor changes in blood supply to a tumor during sunitinib treatment in a patient with localized renal cell carcinoma. A 43-year-old Japanese woman with a tumor-bearing but functional single kidney presented at our hospital in July 2012. Computed tomography and magnetic resonance imaging revealed a cT1aN0M0 renal cell carcinoma embedded in the upper central region of the left kidney. She was prescribed sunitinib as neoadjuvant therapy for 8 months, and then underwent partial nephrectomy. Tumor monitoring during this time was done using time-resolved three-dimensional phase-contrast magnetic resonance imaging, a recent technique which specifically measures blood flow in the various vessels of the kidney. This imaging allowed visualization of the redistribution of renal blood flow during treatment, and showed that flow to the tumor was decreased and flows to other areas increased. Of note, this change occurred in the absence of any change in tumor size. The ability of time-resolved three-dimensional phase-contrast magnetic resonance imaging to provide quantitative information on blood supply to tumors may be useful in monitoring the efficacy of sunitinib treatment.

  16. Three dimensional visualization of medical images

    International Nuclear Information System (INIS)

    Suto, Yasuzo

    1992-01-01

    Three dimensional visualization is a stereoscopic technique that allows the diagnosis and treatment of complicated anatomy site of the bone and organ. In this article, the current status and technical application of three dimensional visualization are introduced with special reference to X-ray CT and MRI. The surface display technique is the most common for three dimensional visualization, consisting of geometric model, voxel element, and stereographic composition techniques. Recent attention has been paid to display method of the content of the subject called as volume rendering, whereby information on the living body is provided accurately. The application of three dimensional visualization is described in terms of diagnostic imaging and surgical simulation. (N.K.)

  17. Three-Dimensional Flows

    CERN Document Server

    Araujo, Vitor; Viana, Marcelo

    2010-01-01

    In this book, the authors present the elements of a general theory for flows on three-dimensional compact boundaryless manifolds, encompassing flows with equilibria accumulated by regular orbits. The book aims to provide a global perspective of this theory and make it easier for the reader to digest the growing literature on this subject. This is not the first book on the subject of dynamical systems, but there are distinct aspects which together make this book unique. Firstly, this book treats mostly continuous time dynamical systems, instead of its discrete counterpart, exhaustively treated

  18. Three dimensional system integration

    CERN Document Server

    Papanikolaou, Antonis; Radojcic, Riko

    2010-01-01

    Three-dimensional (3D) integrated circuit (IC) stacking is the next big step in electronic system integration. It enables packing more functionality, as well as integration of heterogeneous materials, devices, and signals, in the same space (volume). This results in consumer electronics (e.g., mobile, handheld devices) which can run more powerful applications, such as full-length movies and 3D games, with longer battery life. This technology is so promising that it is expected to be a mainstream technology a few years from now, less than 10-15 years from its original conception. To achieve thi

  19. Confidence in Assessment of Lumbar Spondylolysis Using Three-Dimensional Volumetric T2-Weighted MRI Compared With Limited Field of View, Decreased-Dose CT.

    Science.gov (United States)

    Delavan, Joshua Adam; Stence, Nicholas V; Mirsky, David M; Gralla, Jane; Fadell, Michael F

    2016-07-01

    Limited z-axis-coverage computed tomography (CT) to evaluate for pediatric lumbar spondylolysis, altering the technique such that the dose to the patient is comparable or lower than radiographs, is currently used at our institution. The objective of the study was to determine whether volumetric 3-dimensional fast spin echo magnetic resonance imaging (3D MRI) can provide equal or greater diagnostic accuracy compared with limited CT in the diagnosis of pediatric lumbar spondylolysis without ionizing radiation. Volumetric 3D MRI can provide equal or greater diagnostic accuracy compared with low-dose CT for pediatric lumbar spondylolysis without ionizing radiation. Clinical review. Level 2. Three pediatric neuroradiologists evaluated 2-dimensional (2D) MRI, 2D + 3D MRI, and limited CT examinations in 42 pediatric patients who obtained imaging for low back pain and suspected spondylolysis. As there is no gold standard for the diagnosis of spondylolysis besides surgery, interobserver agreement and degree of confidence were compared to determine which modality is preferable. Decreased-dose CT provided a greater level of agreement than 2D MRI and 2D + 3D MRI. The kappa for rater agreement with 2D MRI, 2D + 3D MRI, and CT was 0.19, 0.32, and 1.0, respectively. All raters agreed in 31%, 40%, and 100% of cases with 2D MRI, 2D + 3D MRI, and CT. Lack of confidence was significantly lower with CT (0%) than with 2D MRI (30%) and 2D + 3D MRI (25%). For diagnosing spondylolysis, radiologist agreement and confidence trended toward improvement with the addition of a volumetric 3D MRI sequence to standard 2D MRI sequences compared with 2D MRI alone; however, agreement and confidence remain significantly greater using decreased-dose CT when compared with either MRI acquisition. Decreased-dose CT of the lumbar spine remains the optimal examination to confirm a high suspicion of spondylolysis, with dose essentially equivalent to radiographs. If clinical symptoms are not classic for

  20. Three Dimensional Dirac Semimetals

    Science.gov (United States)

    Zaheer, Saad

    2014-03-01

    Dirac points on the Fermi surface of two dimensional graphene are responsible for its unique electronic behavior. One can ask whether any three dimensional materials support similar pseudorelativistic physics in their bulk electronic spectra. This possibility has been investigated theoretically and is now supported by two successful experimental demonstrations reported during the last year. In this talk, I will summarize the various ways in which Dirac semimetals can be realized in three dimensions with primary focus on a specific theory developed on the basis of representations of crystal spacegroups. A three dimensional Dirac (Weyl) semimetal can appear in the presence (absence) of inversion symmetry by tuning parameters to the phase boundary separating a bulk insulating and a topological insulating phase. More generally, we find that specific rules governing crystal symmetry representations of electrons with spin lead to robust Dirac points at high symmetry points in the Brillouin zone. Combining these rules with microscopic considerations identifies six candidate Dirac semimetals. Another method towards engineering Dirac semimetals involves combining crystal symmetry and band inversion. Several candidate materials have been proposed utilizing this mechanism and one of the candidates has been successfully demonstrated as a Dirac semimetal in two independent experiments. Work carried out in collaboration with: Julia A. Steinberg, Steve M. Young, J.C.Y. Teo, C.L. Kane, E.J. Mele and Andrew M. Rappe.

  1. MRI of the lumbar spine: comparison of 3D isotropic turbo spin-echo SPACE sequence versus conventional 2D sequences at 3.0 T.

    Science.gov (United States)

    Lee, Sungwon; Jee, Won-Hee; Jung, Joon-Yong; Lee, So-Yeon; Ryu, Kyeung-Sik; Ha, Kee-Yong

    2015-02-01

    Three-dimensional (3D) fast spin-echo sequence with variable flip-angle refocusing pulse allows retrospective alignments of magnetic resonance imaging (MRI) in any desired plane. To compare isotropic 3D T2-weighted (T2W) turbo spin-echo sequence (TSE-SPACE) with standard two-dimensional (2D) T2W TSE imaging for evaluating lumbar spine pathology at 3.0 T MRI. Forty-two patients who had spine surgery for disk herniation and had 3.0 T spine MRI were included in this study. In addition to standard 2D T2W TSE imaging, sagittal 3D T2W TSE-SPACE was obtained to produce multiplanar (MPR) images. Each set of MR images from 3D T2W TSE and 2D TSE-SPACE were independently scored for the degree of lumbar neural foraminal stenosis, central spinal stenosis, and nerve compression by two reviewers. These scores were compared with operative findings and the sensitivities were evaluated by McNemar test. Inter-observer agreements and the correlation with symptoms laterality were assessed with kappa statistics. The 3D T2W TSE and 2D TSE-SPACE had similar sensitivity in detecting foraminal stenosis (78.9% versus 78.9% in 32 foramen levels), spinal stenosis (100% versus 100% in 42 spinal levels), and nerve compression (92.9% versus 81.8% in 59 spinal nerves). The inter-observer agreements (κ = 0.849 vs. 0.451 for foraminal stenosis, κ = 0.809 vs. 0.503 for spinal stenosis, and κ = 0.681 vs. 0.429 for nerve compression) and symptoms correlation (κ = 0.449 vs. κ = 0.242) were better in 3D TSE-SPACE compared to 2D TSE. 3D TSE-SPACE with oblique coronal MPR images demonstrated better inter-observer agreements compared to 3D TSE-SPACE without oblique coronal MPR images (κ = 0.930 vs. κ = 0.681). Isotropic 3D T2W TSE-SPACE at 3.0 T was comparable to 2D T2W TSE for detecting foraminal stenosis, central spinal stenosis, and nerve compression with better inter-observer agreements and symptom correlation. © The Foundation Acta Radiologica 2014 Reprints and

  2. Three dimensional energy profile:

    International Nuclear Information System (INIS)

    Kowsari, Reza; Zerriffi, Hisham

    2011-01-01

    The provision of adequate, reliable, and affordable energy has been considered as a cornerstone of development. More than one-third of the world's population has a very limited access to modern energy services and suffers from its various negative consequences. Researchers have been exploring various dimensions of household energy use in order to design strategies to provide secure access to modern energy services. However, despite more than three decades of effort, our understanding of household energy use patterns is very limited, particularly in the context of rural regions of the developing world. Through this paper, the past and the current trends in the field of energy analysis are investigated. The literature on rural energy and energy transition in developing world has been explored and the factors affecting households' decisions on energy use are listed. The and the factors affecting households' decisions on energy use are listed. The gaps identified in the literature on rural household energy analysis provide a basis for developing an alternative model that can create a more realistic view of household energy use. The three dimensional energy profile is presented as a new conceptual model for assessment of household energy use. This framework acts as a basis for building new theoretical and empirical models of rural household energy use. - Highlights: ► Reviews literature on household energy, energy transitions and decision-making in developing countries. ► Identifies gaps in rural household energy analysis and develops a new conceptual framework. ► The 3-d energy profile provides a holistic view of household energy system characteristics. ► Illustrates the use of the framework for understanding household energy transitions.

  3. Three-dimensional echocardiography

    International Nuclear Information System (INIS)

    Buck, Thomas

    2011-01-01

    Presents tips and tricks for beginners and experts Provides educational material for 3D training courses Features comprehensively illustrated cases Includes an accompanying DVD with video clips of all sample cases Three-dimensional echocardiography is the most recent fundamental advancement in echocardiography. Since real-time 3D echocardiography became commercially available in 2002, it has rapidly been accepted in echo labs worldwide. This book covers all clinically relevant aspects of this fascinating new technology, including a comprehensive explanation of its basic principles, practical aspects of clinical application, and detailed descriptions of specific uses in the broad spectrum of clinically important heart disease. The book was written by a group of well-recognized international experts in the field, who have not only been involved in the scientific and clinical evolution of 3D echocardiography since its inception but are also intensively involved in expert training courses. As a result, the clear focus of this book is on the practical application of 3D echocardiography in daily clinical routine with tips and tricks for both beginners and experts, accompanied by more than 150 case examples comprehensively illustrated in more than 800 images and more than 500 videos provided on a DVD. In addition to an in-depth review of the most recent literature on real-time 3D echocardiography, this book represents an invaluable reference work for beginners and expert users of 3D echocardiography. - Tips and tricks for beginners and experts - Educational material for 3D training courses - Comprehensively illustrated cases - DVD with video clips of all sample cases.

  4. Three-dimensional ICT reconstruction

    International Nuclear Information System (INIS)

    Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

    2005-01-01

    The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context, qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

  5. Three-dimensional ICT reconstruction

    International Nuclear Information System (INIS)

    Zhang Aidong; Li Ju; Chen Fa; Sun Lingxia

    2004-01-01

    The three-dimensional ICT reconstruction method is the hot topic of recent ICT technology research. In the context qualified visual three-dimensional ICT pictures are achieved through multi-piece two-dimensional images accumulation by order, combining with thresholding method and linear interpolation. Different direction and different position images of the reconstructed pictures are got by rotation and interception respectively. The convenient and quick method is significantly instructive to more complicated three-dimensional reconstruction of ICT images. (authors)

  6. Three dimensional MEMS supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Wei

    2011-10-15

    The overall objective of this research is to achieve compact supercapacitors with high capacitance, large power density, and long cycle life for using as micro power sources to drive low power devices and sensors. The main shortcoming of supercapacitors as a power source is that its energy density typically is about 1/10 of that of batteries. To achieve compact supercapacitors of large energy density, supercapacitors must be developed with high capacitance and power density which are mainly depended on the effective surface area of the electrodes of the supercapacitors. Many studies have been done to increase the effective surface area by modifying the electrode materials, however, much less investigations are focus on machining the electrodes. In my thesis work, micro- and nano-technologies are applied as technology approaches for machining the electrodes with three dimensional (3D) microstructures. More specific, Micro-electro-mechanical system (MEMS) fabrication process flow, which integrates the key process such as LIGA-like (German acronym for Lithographie, Galvanoformung, Abformung, which mean Lithography, Electroplating and Molding) technology or DRIE (deep reactive ion etching), has been developed to enable innovative designs of 3D MEMS supercapacitors which own the electrodes of significantly increased geometric area. Two types of 3D MEMS supercapcitors, based on LIGA-like and DRIE technology respectively, were designed and successfully created. The LIGA-like based 3D MEMS supercapacitor is with an interdigital 3D structure, and consists of silicon substrate, two electroplated nickel current collectors, two PPy (poly pyrrole) electrodes, and solid state electrolyte. The fabrication process flow developed includes the flowing key processes, SU-8 lithography, nickel electroplating, PPy polymerization and solid state electrolyte coating. Electrochemical tests showed that the single electrode of the supercapacitor has the specific capacitance of 0.058 F cm-2

  7. Fully three-dimensional reconstruction from data collected on concentric cubes in Fourier space: implementation and a sample application to MRI [magnetic resonance imaging

    International Nuclear Information System (INIS)

    Herman, G.T.; Roberts, D.; Axel, L.

    1992-01-01

    An algorithm is proposed for rapid and accurate reconstruction from data collected in Fourier space at points arranged on a grid of concentric cubes. The whole process has computational complexity of the same order as required for the 3D fast Fourier transform and so (for medically relevant sizes of the data set) it is faster than backprojection into the same size rectangular grid. The design of the algorithm ensures that no interpolations are needed, in contrast to methods involving backprojection with their unavoidable interpolations. As an application, a 3D data collection method for MRI has been designed which directly samples the Fourier transform of the object to be reconstructed on concentric cubes as needed for the algorithm. (author)

  8. The relationship between three-dimensional knee MRI bone shape and total knee replacement—a case control study: data from the Osteoarthritis Initiative

    Science.gov (United States)

    Barr, Andrew J.; Dube, Bright; Hensor, Elizabeth M. A.; Kingsbury, Sarah R.; Peat, George; Bowes, Mike A.; Sharples, Linda D.

    2016-01-01

    Objective. There is growing understanding of the importance of bone in OA. Our aim was to determine the relationship between 3D MRI bone shape and total knee replacement (TKR). Methods. A nested case-control study within the Osteoarthritis Initiative cohort identified case knees with confirmed TKR for OA and controls that were matched using propensity scores. Active appearance modelling quantification of the bone shape of all knee bones identified vectors between knees having or not having OA. Vectors were scaled such that −1 and +1 represented the mean non-OA and mean OA shapes. Results. Compared to controls (n = 310), TKR cases (n = 310) had a more positive mean baseline 3D bone shape vector, indicating more advanced structural OA, for the femur [mean 0.98 vs −0.11; difference (95% CI) 1.10 (0.88, 1.31)], tibia [mean 0.86 vs −0.07; difference (95% CI) 0.94 (0.72, 1.16)] and patella [mean 0.95 vs 0.03; difference (95% CI) 0.92 (0.65, 1.20)]. Odds ratios (95% CI) for TKR per normalized unit of 3D bone shape vector for the femur, tibia and patella were: 1.85 (1.59, 2.16), 1.64 (1.42, 1.89) and 1.36 (1.22, 1.50), respectively, all P < 0.001. After including Kellgren–Lawrence grade in a multivariable analysis, only the femur 3D shape vector remained significantly associated with TKR [odds ratio 1.24 (1.02, 1.51)]. Conclusion. 3D bone shape was associated with the endpoint of this study, TKR, with femoral shape being most associated. This study contributes to the validation of quantitative MRI bone biomarkers for OA structure-modification trials. PMID:27185958

  9. Three-dimensional contrast-enhanced MRI using an intravascular contrast agent for detection of traumatic intra-abdominal hemorrhage and abdominal parenchymal injuries: an experimental study

    International Nuclear Information System (INIS)

    Weishaupt, D.; Ruehm, S.G.; Patak, M.A.; Schmidt, M.; Debatin, J.F.; Hetzer, F.H.

    2000-01-01

    The aim of this study was to compare the performance of 3D MRI in conjunction with an intravascular contrast agent to spiral contrast-enhanced CT, regarding the detection of abdominal parenchymal injuries as well as peritoneal hemorrhage in an animal model. Liver and kidney injuries were created surgically in six female pigs under general anesthesia. All pigs underwent contrast-enhanced spiral CT and 3D MR imaging following administration of an intravascular contrast agent (NC100150 Injection). Two readers rated their confidence independently on MR and CT data sets using a five-point scale for the presence of organ injury and hemoperitoneum. Autopsy findings served as standard of reference. Sensitivity and specificity for MR in detecting hepatic and renal injuries as well as hemoperitoneum was 100 %. Computed tomography was less accurate with sensitivity and specificity values of 90 and 94 %, respectively. Receiver operating characteristics (ROC) analysis revealed a higher confidence when interpretation was based on MR images. In an animal model 3D MR imaging in conjunction with an intravascular contrast agent proved highly accurate in detecting and localizing parenchymal injuries to the upper abdomen as well as in detecting intraperitoneal blood collections. (orig.)

  10. MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Jisook; Cha, Jang Gyu [Soonchunhyang University Bucheon Hospital, Department of Radiology, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Young Koo [Soonchunhyang University Bucheon Hospital, Department of Orthopedics, Wonmi-gu, Bucheon-si (Korea, Republic of); Lee, Bo Ra [Soonchunhyang University Bucheon Hospital, Department of Biomedical Statistics, Wonmi-gu, Bucheon-si (Korea, Republic of); Jeon, Chan Hong [Soonchunhyang University Bucheon Hospital, Division of Rheumatology, Department of Internal Medicine, Wonmi-gu, Bucheon-si (Korea, Republic of)

    2016-07-15

    To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs. (orig.)

  11. MRI of the anterior talofibular ligament, talar cartilage and os subfibulare: Comparison of isotropic resolution 3D and conventional 2D T2-weighted fast spin-echo sequences at 3.0 T

    International Nuclear Information System (INIS)

    Yi, Jisook; Cha, Jang Gyu; Lee, Young Koo; Lee, Bo Ra; Jeon, Chan Hong

    2016-01-01

    To determine the accuracy of a three-dimensional (3D) T2-weighted fast spin-echo (FSE) magnetic resonance (MR) sequence compared with two-dimensional (2D) sequence for diagnosing anterior talofibular ligament (ATFL) tears, chondral lesion of the talus (CLT) and os subfibulare/avulsion fracture of the distal fibula (OSF). Thirty-five patients were included, who had undergone ankle MRI with 3D T2-weighted FSE and 2D T2-weighted FSE sequences, as well as subsequent ankle arthroscopy, between November 2013 and July 2014. Each MR imaging sequence was independently scored by two readers retrospectively for the presence of ATFL tears, CLT and OSF. The area under the receiver operating curve (AUC) was compared to determine the discriminatory power of the two image sequences. Interobserver agreement was expressed as unweighted kappa value. Arthroscopic findings confirmed 21 complete tears of the ATFL, 14 partial tears of the ATFL, 17 CLTs and 7 OSFs. There were no significant differences in the diagnoses of ATFL tears (p = 0.074-0.501), CLT (p = 0.090-0.450) and OSF (p = 0.317) obtained from the 2D and 3D sequences by either reader. The interobserver agreement rates between two readers using the 3D T2-weighted FSE sequence versus those obtained with the 2D sequence were substantial (κ = 0.659) versus moderate (κ = 0.553) for ATFL tears, moderate (κ = 0.499) versus substantial (κ = 0.676) for CLT and substantial (κ = 0.621) versus substantial (κ = 0.689) for OSF. Three-dimensional isotropic T2-weighted FSE MRI of the ankle resulted in no statistically significant difference in diagnostic performance compared to two-dimensional T2-weighted FSE MRI in the evaluation of ATFL tears, CLTs and OSFs. (orig.)

  12. Utility of three-dimensional method for diagnosing meniscal lesions

    International Nuclear Information System (INIS)

    Ohshima, Suguru; Nomura, Kazutoshi; Hirano, Mako; Hashimoto, Noburo; Fukumoto, Tetsuya; Katahira, Kazuhiro

    1998-01-01

    MRI of the knee is a useful method for diagnosing meniscal tears. Although the spin echo method is usually used for diagnosing meniscal tears, we examined the utility of thin slice scan with the three-dimensional method. We reviewed 70 menisci in which arthroscopic findings were confirmed. In this series, sensitivity was 90.9% for medial meniscal injuries and 68.8% for lateral meniscal injuries. There were 3 meniscal tears in which we could not detect tears on preoperative MRI. We could find tears in two of these cases when re-evaluated using the same MRI. In conclusion, we can get the same diagnostic rate with the three-dimensional method compared with the spin echo method. Scan time of the three-dimensional method is 3 minutes, on the other hand that of spin echo method in 17 minutes. This slice scan with three-dimensional method is useful for screening meniscal injuries before arthroscopy. (author)

  13. Effects of forcing in three-dimensional turbulent flows

    NARCIS (Netherlands)

    Biferale, L.; Lanotte, A.; Toschi, F.

    2004-01-01

    We present the results of a numerical investigation of three-dimensional homogeneous and isotropic turbulence, stirred by a random forcing with a power-law spectrum, Ef(k)~k3-y. Numerical simulations are performed at different resolutions up to 5123. We show that at varying the spectrum slope y,

  14. Rapid whole-brain resting-state fMRI at 3 T: Efficiency-optimized three-dimensional EPI versus repetition time-matched simultaneous-multi-slice EPI.

    Science.gov (United States)

    Stirnberg, Rüdiger; Huijbers, Willem; Brenner, Daniel; Poser, Benedikt A; Breteler, Monique; Stöcker, Tony

    2017-12-01

    State-of-the-art simultaneous-multi-slice (SMS-)EPI and 3D-EPI share several properties that benefit functional MRI acquisition. Both sequences employ equivalent parallel imaging undersampling with controlled aliasing to achieve high temporal sampling rates. As a volumetric imaging sequence, 3D-EPI offers additional means of acceleration complementary to 2D-CAIPIRINHA sampling, such as fast water excitation and elliptical sampling. We performed an application-oriented comparison between a tailored, six-fold CAIPIRINHA-accelerated 3D-EPI protocol at 530 ms temporal and 2.4 mm isotropic spatial resolution and an SMS-EPI protocol with identical spatial and temporal resolution for whole-brain resting-state fMRI at 3 T. The latter required eight-fold slice acceleration to compensate for the lack of elliptical sampling and fast water excitation. Both sequences used vendor-supplied on-line image reconstruction. We acquired test/retest resting-state fMRI scans in ten volunteers, with simultaneous acquisition of cardiac and respiration data, subsequently used for optional physiological noise removal (nuisance regression). We found that the 3D-EPI protocol has significantly increased temporal signal-to-noise ratio throughout the brain as compared to the SMS-EPI protocol, especially when employing motion and nuisance regression. Both sequence types reliably identified known functional networks with stronger functional connectivity values for the 3D-EPI protocol. We conclude that the more time-efficient 3D-EPI primarily benefits from reduced parallel imaging noise due to a higher, actual k-space sampling density compared to SMS-EPI. The resultant BOLD sensitivity increase makes 3D-EPI a valuable alternative to SMS-EPI for whole-brain fMRI at 3 T, with voxel sizes well below 3 mm isotropic and sampling rates high enough to separate dominant cardiac signals from BOLD signals in the frequency domain. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Differentiation between grade 3 and grade 4 articular cartilage defects of the knee: Fat-suppressed proton density-weighted versus fat-suppressed three-dimensional gradient-echo MRI

    Energy Technology Data Exchange (ETDEWEB)

    Lee, So Yeon; Jee, Won-Hee; Kim, Sun Ki (Dept. of Radiology, Seoul St Mary' s Hospital, Catholic Univ. of Korea, Seoul (Korea)), e-mail: whjee@catholic.ac.kr; Koh, In-Jun (Dept. of Joint Reconstruction Center, Seoul National Univ. Bundang Hospital, Seoul (Korea)); Kim, Jung-Man (Dept. of Orthopedic Surgery, Seoul St Mary' s Hospital, Catholic Univ. of Korea, Seoul (Korea))

    2010-05-15

    Background: Fat-suppressed (FS) proton density (PD)-weighted magnetic resonance imaging (MRI) and FS three-dimensional (3D) gradient-echo imaging such as spoiled gradient-recalled (SPGR) sequence have been established as accurate methods for detecting articular cartilage defects. Purpose: To retrospectively compare the diagnostic efficacy between FS PD-weighted and FS 3D gradient-echo MRI for differentiating between grade 3 and grade 4 cartilage defects of the knee with arthroscopy as the standard of reference. Material and Methods: Twenty-one patients who had grade 3 or 4 cartilage defects in medial femoral condyle at arthroscopy and knee MRI were included in this study: grade 3, >50% cartilage defects; grade 4, full thickness cartilage defects exposed to the bone. Sagittal FS PD-weighted MR images and FS 3D gradient-echo images with 1.5 T MR images were independently graded for the cartilage abnormalities of medial femoral condyle by two musculoskeletal radiologists. Statistical analysis was performed by Fisher's exact test. Inter-observer agreement in grading of cartilage was assessed using ? coefficients. Results: Arthroscopy revealed grade 3 defects in 17 patients and grade 4 defects in 4 patients in medial femoral condyles. For FS 3D gradient-echo images grade 3 defects were graded as grade 3 (n=15) and grade 4 (n=2), and all grade 4 defects (n=4) were correctly graded. However, for FS PD-weighted MR images all grade 3 defects were misinterpreted as grade 1 (n=1) and grade 4 (n=16), whereas all grade 4 defects (n=4) were correctly graded. FS 3D gradient-echo MRI could differentiate grade 3 from grade 4 defects (P=0.003), whereas FS PD-weighted imaging could not (P=1.0). Inter-observer agreement was substantial (?=0.70) for grading of cartilage using FS PD-weighted imaging, whereas it was moderate (?=0.46) using FS 3D gradient-echo imaging. Conclusion: FS 3D gradient-echo MRI is more helpful for differentiating between grade 3 and grade 4 cartilage

  16. MRI of the popliteofibular ligament: isotropic 3D WE-DESS versus coronal oblique fat-suppressed T2W MRI

    International Nuclear Information System (INIS)

    Rajeswaran, G.; Lee, J.C.; Healy, J.C.

    2007-01-01

    The objective was to compare isotropic 3D water excitation double-echo steady state (WE-DESS) MRI with coronal oblique fat-suppressed T2-weighted (FS T2W) images in the identification of the popliteofibular ligament (PFL). A prospective analysis of 122 consecutive knee MRIs was performed in patients referred for knee pain from the orthopaedic clinic. In addition to the standard knee sequences, isotropic WE-DESS volume acquisition through the whole knee and coronal oblique FS T2W fast spin echo sequences through the posterolateral corner were obtained. The presence of the popliteus and biceps femoris tendons, lateral collateral and PFL was documented. Anterior cruciate ligament injury was present in 33 cases and these were excluded from the study because of the risk of associated PFL injury, leaving a total of 89 cases. Of the 42 patients in whom arthroscopic evaluation was subsequently obtained, none were found to have an injury to the PFL. The lateral collateral ligament, biceps femoris and popliteus tendon were identified in all cases on all sequences. The PFL was seen in 81 (91.0%; 95% CI 85.1-97.0%) patients using the WE-DESS sequence and 63 (70.8%; 95% CI 61.3-80.2%) patients using the coronal oblique FS T2W sequence, a statistically significant difference (p < 0.00005). Isotropic 3D WE-DESS MRI significantly enhances our ability to identify the popliteofibular ligament compared with coronal oblique fat-suppressed T2-weighted images. (orig.)

  17. Three-dimensional biomedical imaging

    International Nuclear Information System (INIS)

    Robb, R.A.

    1985-01-01

    Scientists in biomedical imaging provide researchers, physicians, and academicians with an understanding of the fundamental theories and practical applications of three-dimensional biomedical imaging methodologies. Succinct descriptions of each imaging modality are supported by numerous diagrams and illustrations which clarify important concepts and demonstrate system performance in a variety of applications. Comparison of the different functional attributes, relative advantages and limitations, complementary capabilities, and future directions of three-dimensional biomedical imaging modalities are given. Volume 1: Introductions to Three-Dimensional Biomedical Imaging Photoelectronic-Digital Imaging for Diagnostic Radiology. X-Ray Computed Tomography - Basic Principles. X-Ray Computed Tomography - Implementation and Applications. X-Ray Computed Tomography: Advanced Systems and Applications in Biomedical Research and Diagnosis. Volume II: Single Photon Emission Computed Tomography. Position Emission Tomography (PET). Computerized Ultrasound Tomography. Fundamentals of NMR Imaging. Display of Multi-Dimensional Biomedical Image Information. Summary and Prognostications

  18. Isotropic 3D cardiac cine MRI allows efficient sparse segmentation strategies based on 3D surface reconstruction.

    Science.gov (United States)

    Odille, Freddy; Bustin, Aurélien; Liu, Shufang; Chen, Bailiang; Vuissoz, Pierre-André; Felblinger, Jacques; Bonnemains, Laurent

    2018-05-01

    Segmentation of cardiac cine MRI data is routinely used for the volumetric analysis of cardiac function. Conventionally, 2D contours are drawn on short-axis (SAX) image stacks with relatively thick slices (typically 8 mm). Here, an acquisition/reconstruction strategy is used for obtaining isotropic 3D cine datasets; reformatted slices are then used to optimize the manual segmentation workflow. Isotropic 3D cine datasets were obtained from multiple 2D cine stacks (acquired during free-breathing in SAX and long-axis (LAX) orientations) using nonrigid motion correction (cine-GRICS method) and super-resolution. Several manual segmentation strategies were then compared, including conventional SAX segmentation, LAX segmentation in three views only, and combinations of SAX and LAX slices. An implicit B-spline surface reconstruction algorithm is proposed to reconstruct the left ventricular cavity surface from the sparse set of 2D contours. All tested sparse segmentation strategies were in good agreement, with Dice scores above 0.9 despite using fewer slices (3-6 sparse slices instead of 8-10 contiguous SAX slices). When compared to independent phase-contrast flow measurements, stroke volumes computed from four or six sparse slices had slightly higher precision than conventional SAX segmentation (error standard deviation of 5.4 mL against 6.1 mL) at the cost of slightly lower accuracy (bias of -1.2 mL against 0.2 mL). Functional parameters also showed a trend to improved precision, including end-diastolic volumes, end-systolic volumes, and ejection fractions). The postprocessing workflow of 3D isotropic cardiac imaging strategies can be optimized using sparse segmentation and 3D surface reconstruction. Magn Reson Med 79:2665-2675, 2018. © 2017 International Society for Magnetic Resonance in Medicine. © 2017 International Society for Magnetic Resonance in Medicine.

  19. The role of isotropic diffusion MRI in children under 2 years of age

    International Nuclear Information System (INIS)

    Gelal, F.M.; Grant, P.E.; Fischbein, N.J.; Henry, R.G.; Vigneron, D.B.; Barkovich, A.J.

    2001-01-01

    Our objective was to determine the contribution of diffusion MR imaging to standard MR imaging in the neuroradiological evaluation of children less than 2 years of age. Echo-planar diffusion MR imaging was added to standard MR exams in 75 consecutive patients under the age of 2 years. Single-shot echo-planar spin-echo T2 weighted images (EPSE-T2) were acquired. Isotropic diffusion-weighted images (DWI), attenuation coefficient maps (ACM), and apparent diffusion coefficient (ADC) maps were calculated offline from images obtained with diffusion gradients (b=1000 s/mm 2 ) in three orthogonal directions. Two neuroradiologists determined if EPSE-T2, DWI, or ACM contributed new information to spin-echo proton density (SE PD) and T2 studies. In 15 of 18 abnormalities detected in 8 patients with symptoms less than 1 week in duration, DWI and/or ACM added information to SE PD and T2. Diffusion sequences detected five new lesions, showed six lesions with greater conspicuity, and identified four lesions with different diffusion character. In patients with symptoms of more than 7 days duration, diffusion studies added no information. Isotropic diffusion MR contributed to lesion detection and characterization in infants when symptoms were less than 1 week in duration. Diffusion MR is useful in patients with leukodystrophies, metabolic disorders, and patients with acute ischemic lesions. (orig.)

  20. (Weakly) three-dimensional caseology

    International Nuclear Information System (INIS)

    Pomraning, G.C.

    1996-01-01

    The singular eigenfunction technique of Case for solving one-dimensional planar symmetry linear transport problems is extended to a restricted class of three-dimensional problems. This class involves planar geometry, but with forcing terms (either boundary conditions or internal sources) which are weakly dependent upon the transverse spatial variables. Our analysis involves a singular perturbation about the classic planar analysis, and leads to the usual Case discrete and continuum modes, but modulated by weakly dependent three-dimensional spatial functions. These functions satisfy parabolic differential equations, with a different diffusion coefficient for each mode. Representative one-speed time-independent transport problems are solved in terms of these generalised Case eigenfunctions. Our treatment is very heuristic, but may provide an impetus for more rigorous analysis. (author)

  1. An anatomical study of normal meniscal roots with isotropic 3D MRI at 3 T

    International Nuclear Information System (INIS)

    Ren Ahong; Zheng Zhuozhao; Shang Yao; Tian Chunyan

    2012-01-01

    Objectives: To clarify the morphological features of normal meniscal roots on magnetic resonance (MR) imaging with an isotropic 3D proton density-weighted (PDW) sequence. Materials: 3D PDW MR was performed in sixty-two patients at 3 T before knee arthroscopy. MR images of 34 normal medial menisci and 33 intact lateral menisci confirmed by arthroscopy were retrospectively evaluated. MR signals, insertion sites, dimensions and courses of four meniscal roots were recorded. Results: The anterior root of medial meniscus (ARMM) was typically hypointense, while the posterior root of medial meniscus (PRMM) and the anterior root of lateral meniscus (ARLM) were prone to be hyperintense or showing a comblike signal, and the posterior root of lateral meniscus (PRLM) was usually hypointense or comblike on PDW MR images. ARMM and PRLM had more complex and diverse insertion patterns than ARLM and PRMM. There were significant statistical differences of the lengths, widths, heights and course angles among four meniscal roots (all P < 0.001). Conclusions: The signal intensity of each meniscal root can be hypointense, hyperintense, or comblike on 3D PDW MR images. ARMM and PRLM have more complex and diverse insertion patterns than ARLM and PRMM. The dimensions and courses of four meniscal roots all differ.

  2. Equilibrium: three-dimensional configurations

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    This chapter considers toroidal MHD configurations that are inherently three-dimensional. The motivation for investigation such complicated equilibria is that they possess the potential for providing toroidal confinement without the need of a net toroidal current. This leads to a number of advantages with respect to fusion power generation. First, the attractive feature of steady-state operation becomes more feasible since such configurations no longer require a toroidal current transformer. Second, with zero net current, one potentially dangerous class of MHD instabilities, the current-driven kink modes, is eliminated. Finally, three-dimensional configurations possess nondegenerate flux surfaces even in the absence of plasma pressure and plasma current. Although there is an enormous range of possible three-dimensional equilibria, the configurations of interest are accurately described as axisymmetric tori with superimposed helical fields; furthermore, they possess no net toroidal current. Instead, two different and less obvious restoring forces are developed: the helical sideband force and the toroidal dipole current force. Each is discussed in detail in Chapter 7. A detailed discussion of the parallel current constraint, including its physical significance, is given in section 7.2. A general analysis of helical sideband equilibria, along with a detailed description of the Elmo bumpy torus, is presented in sections 7.3 and 7.4. A general description of toroidal dipole-current equilibria, including a detailed discussion of stellarators, heliotrons, and torsatrons, is given in sections 7.5 and 7.6

  3. Three-dimensional aromatic networks.

    Science.gov (United States)

    Toyota, Shinji; Iwanaga, Tetsuo

    2014-01-01

    Three-dimensional (3D) networks consisting of aromatic units and linkers are reviewed from various aspects. To understand principles for the construction of such compounds, we generalize the roles of building units, the synthetic approaches, and the classification of networks. As fundamental compounds, cyclophanes with large aromatic units and aromatic macrocycles with linear acetylene linkers are highlighted in terms of transannular interactions between aromatic units, conformational preference, and resolution of chiral derivatives. Polycyclic cage compounds are constructed from building units by linkages via covalent bonds, metal-coordination bonds, or hydrogen bonds. Large cage networks often include a wide range of guest species in their cavity to afford novel inclusion compounds. Topological isomers consisting of two or more macrocycles are formed by cyclization of preorganized species. Some complicated topological networks are constructed by self-assembly of simple building units.

  4. Clinical significance of three-dimensional sonohysterography

    International Nuclear Information System (INIS)

    Lee, Eun Hye; Lee, Mi Hwa; Lee, Chan; Kim, Jong Wook; Shin, Myung Choel

    1999-01-01

    To evaluate the usefulness of three dimensional sonohysterography (3D SHG) in the evaluation of uterine endometrial and submucosal lesions in comparison with conventional two-dimensional sonohysterography (2D SHG). Our series consisted of 26 patients (mean aged 41 years) who complained of uterine bleeding, menorrhagia, or dysmenorrhea. 2D SHG was performed, and then 3D SHG was done after the volume mode was switched on. Simultaneous display of three perpendicular two-dimensional planes and surface rendering of findings on particular section were obtained. We analyzed whether the endometrium was thickened or not, and the location, size, shape, echogenicity, posterior shadowing, and echogenic rim of the focal lesion. The results were compared with the pathologic findings or MRI. There were submucosal myomas (n=12), intramural myomas (n=2), endometrial polyps (n=7), placental polyp (n=1), and normal endometrial cavities (n=4) on SHG. Nineteen cases were confirmed by pathologic findings or MRI. The results were correlated in 89% (17/19) of the cases. We misdiagnosed 2 cases: focal endometrial hyperplasia and choriocarcinoma were misdiagnosed as endometrial polyp and placental polyp, respectively. Imaging diagnoses were same in the techniques. Comparing with 2D SHG, 3D SHG provided a subjective display of pathologic findings and an additional information about spatial relationship between focal lesion and surroundings.

  5. Clinical significance of three-dimensional sonohysterography

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Eun Hye; Lee, Mi Hwa; Lee, Chan; Kim, Jong Wook; Shin, Myung Choel [Pochon Cha University College of Medicine, Pochon (Korea, Republic of)

    1999-12-15

    To evaluate the usefulness of three dimensional sonohysterography (3D SHG) in the evaluation of uterine endometrial and submucosal lesions in comparison with conventional two-dimensional sonohysterography (2D SHG). Our series consisted of 26 patients (mean aged 41 years) who complained of uterine bleeding, menorrhagia, or dysmenorrhea. 2D SHG was performed, and then 3D SHG was done after the volume mode was switched on. Simultaneous display of three perpendicular two-dimensional planes and surface rendering of findings on particular section were obtained. We analyzed whether the endometrium was thickened or not, and the location, size, shape, echogenicity, posterior shadowing, and echogenic rim of the focal lesion. The results were compared with the pathologic findings or MRI. There were submucosal myomas (n=12), intramural myomas (n=2), endometrial polyps (n=7), placental polyp (n=1), and normal endometrial cavities (n=4) on SHG. Nineteen cases were confirmed by pathologic findings or MRI. The results were correlated in 89% (17/19) of the cases. We misdiagnosed 2 cases: focal endometrial hyperplasia and choriocarcinoma were misdiagnosed as endometrial polyp and placental polyp, respectively. Imaging diagnoses were same in the techniques. Comparing with 2D SHG, 3D SHG provided a subjective display of pathologic findings and an additional information about spatial relationship between focal lesion and surroundings.

  6. Three-dimensional reconstruction of functional brain images

    International Nuclear Information System (INIS)

    Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao

    1999-01-01

    We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

  7. Three-dimensional reconstruction of functional brain images

    Energy Technology Data Exchange (ETDEWEB)

    Inoue, Masato; Shoji, Kazuhiko; Kojima, Hisayoshi; Hirano, Shigeru; Naito, Yasushi; Honjo, Iwao [Kyoto Univ. (Japan)

    1999-08-01

    We consider PET (positron emission tomography) measurement with SPM (Statistical Parametric Mapping) analysis to be one of the most useful methods to identify activated areas of the brain involved in language processing. SPM is an effective analytical method that detects markedly activated areas over the whole brain. However, with the conventional presentations of these functional brain images, such as horizontal slices, three directional projection, or brain surface coloring, makes understanding and interpreting the positional relationships among various brain areas difficult. Therefore, we developed three-dimensionally reconstructed images from these functional brain images to improve the interpretation. The subjects were 12 normal volunteers. The following three types of images were constructed: routine images by SPM, three-dimensional static images, and three-dimensional dynamic images, after PET images were analyzed by SPM during daily dialog listening. The creation of images of both the three-dimensional static and dynamic types employed the volume rendering method by VTK (The Visualization Toolkit). Since the functional brain images did not include original brain images, we synthesized SPM and MRI brain images by self-made C++ programs. The three-dimensional dynamic images were made by sequencing static images with available software. Images of both the three-dimensional static and dynamic types were processed by a personal computer system. Our newly created images showed clearer positional relationships among activated brain areas compared to the conventional method. To date, functional brain images have been employed in fields such as neurology or neurosurgery, however, these images may be useful even in the field of otorhinolaryngology, to assess hearing and speech. Exact three-dimensional images based on functional brain images are important for exact and intuitive interpretation, and may lead to new developments in brain science. Currently, the surface

  8. Three-dimensional morphologic description and visualization of brain anatomy from MR images

    International Nuclear Information System (INIS)

    Kraske, W.; George, F.W.; Zee, C.S.; Colletti, P.M.; Halls, J.M.; Boswell, W.O.

    1989-01-01

    The USC VOXAR-MRI system incorporates MR tissue classification algorithms to provide dynamic three- dimensional volumetric visualization and discrimination of brain anatomy and pathology for precision diagnosis, staging, and treatment planning. The VOXAR-MRI approach to tissue classification employs the three-dimensional reconstruction of various intracranial features from gray-scale morphologic erosion and dilation (GMED)-derived skeleton representation of the MR acquisition. Case presentations include an array of VOXAR-MRI-demonstrated tumors, abscesses, hematomas, and other lesions

  9. Three dimensional imaging of otoliths

    International Nuclear Information System (INIS)

    Barry, B.; Markwitz, A.; David, B.

    2008-01-01

    Otoliths are small structures in fish ears made of calcium carbonate which carry a record of the environment in which the fish live. Traditionally, in order to study their microchemistry by a scanning technique such as PIXE the otoliths have been either ground down by hand or thin sectioned to expose the otolith core. However this technique is subject to human error in judging the core position. In this study we have scanned successive layers of otoliths 50 and 100 μm apart by removing the otolith material in a lapping machine which can be set to a few μm precision. In one study by comparing data from otoliths from the two ears of a freshwater species we found that polishing by hand could miss the core and thus give misleading results as to the life cycle of the fish. In another example we showed detail in a marine species which could be used to build a three dimensional picture of the Sr distribution. (author)

  10. Three-Dimensional Rebar Graphene.

    Science.gov (United States)

    Sha, Junwei; Salvatierra, Rodrigo V; Dong, Pei; Li, Yilun; Lee, Seoung-Ki; Wang, Tuo; Zhang, Chenhao; Zhang, Jibo; Ji, Yongsung; Ajayan, Pulickel M; Lou, Jun; Zhao, Naiqin; Tour, James M

    2017-03-01

    Free-standing robust three-dimensional (3D) rebar graphene foams (GFs) were developed by a powder metallurgy template method with multiwalled carbon nanotubes (MWCNTs) as a reinforcing bar, sintered Ni skeletons as a template and catalyst, and sucrose as a solid carbon source. As a reinforcement and bridge between different graphene sheets and carbon shells, MWCNTs improved the thermostability, storage modulus (290.1 kPa) and conductivity (21.82 S cm -1 ) of 3D GF resulting in a high porosity and structurally stable 3D rebar GF. The 3D rebar GF can support >3150× the foam's weight with no irreversible height change, and shows only a ∼25% irreversible height change after loading >8500× the foam's weight. The 3D rebar GF also shows stable performance as a highly porous electrode in lithium ion capacitors (LICs) with an energy density of 32 Wh kg -1 . After 500 cycles of testing at a high current density of 6.50 mA cm -2 , the LIC shows 78% energy density retention. These properties indicate promising applications with 3D rebar GFs in devices requiring stable mechanical and electrochemical properties.

  11. Three-dimensional magnetotelluric axial anisotropic forward modeling and inversion

    Science.gov (United States)

    Cao, Hui; Wang, Kunpeng; Wang, Tao; Hua, Boguang

    2018-06-01

    Magnetotelluric (MT) data has been widely used to image underground electrical structural. However, when the significant axial resistivity anisotropy presents, how this influences three-dimensional MT data has not been resolved clearly yet. We here propose a scheme for three-dimensional modeling of MT data in presence of axial anisotropic resistivity, where the electromagnetic fields are decomposed into primary and secondary components. A 3D staggered-grid finite difference method is then used to resolve the resulting 3D governing equations. Numerical tests have completed to validate the correctness and accuracy of the present algorithm. A limited-memory Broyden-Fletcher-Goldfarb-Shanno method is then utilized to realize the 3D MT axial anisotropic inversion. The testing results show that, compared to the results of isotropic resistivity inversion, taking account the axial anisotropy can much improve the inverted results.

  12. Three dimensional image alignment, registration and fusion

    International Nuclear Information System (INIS)

    Treves, S.T.; Mitchell, K.D.; Habboush, I.H.

    1998-01-01

    Combined assessment of three dimensional anatomical and functional images (SPECT, PET, MRI, CT) is useful to determine the nature and extent of lesions in many parts of the body. Physicians principally rely on their spatial sense of mentally re-orient and overlap images obtained with different imaging modalities. Objective methods that enable easy and intuitive image registration can help the physician arrive at more optimal diagnoses and better treatment decisions. This review describes a simple, intuitive and robust image registration approach developed in our laboratory. It differs from most other registration techniques in that it allows the user to incorporate all of the available information within the images in the registration process. This method takes full advantage of the ability of knowledgeable operators to achieve image registration and fusion using an intuitive interactive visual approach. It can register images accurately and quickly without the use of elaborate mathematical modeling or optimization techniques. The method provides the operator with tools to manipulate images in three dimensions, including visual feedback techniques to assess the accuracy of registration (grids, overlays, masks, and fusion of images in different colors). Its application is not limited to brain imaging and can be applied to images from any region in the body. The overall effect is a registration algorithm that is easy to implement and can achieve accuracy on the order of one pixel

  13. CAIPIRINHA accelerated SPACE enables 10-min isotropic 3D TSE MRI of the ankle for optimized visualization of curved and oblique ligaments and tendons

    Energy Technology Data Exchange (ETDEWEB)

    Kalia, Vivek [University of Vermont Medical Center, Department of Radiology, Burlington, VT (United States); Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Section of Musculoskeletal Radiology, Baltimore, MD (United States); Fritz, Benjamin [University Medical Center Freiburg, Department of Radiology, Freiburg im Breisgau (Germany); Johnson, Rory [Siemens Healthcare USA, Inc, Cary, NC (United States); Gilson, Wesley D. [Siemens Healthcare USA, Inc, Baltimore, MD (United States); Raithel, Esther [Siemens Healthcare GmbH, Erlangen (Germany); Fritz, Jan [Johns Hopkins University School of Medicine, Russell H. Morgan Department of Radiology and Radiological Science, Section of Musculoskeletal Radiology, Baltimore, MD (United States)

    2017-09-15

    To test the hypothesis that a fourfold CAIPIRINHA accelerated, 10-min, high-resolution, isotropic 3D TSE MRI prototype protocol of the ankle derives equal or better quality than a 20-min 2D TSE standard protocol. Following internal review board approval and informed consent, 3-Tesla MRI of the ankle was obtained in 24 asymptomatic subjects including 10-min 3D CAIPIRINHA SPACE TSE prototype and 20-min 2D TSE standard protocols. Outcome variables included image quality and visibility of anatomical structures using 5-point Likert scales. Non-parametric statistical testing was used. P values ≤0.001 were considered significant. Edge sharpness, contrast resolution, uniformity, noise, fat suppression and magic angle effects were without statistical difference on 2D and 3D TSE images (p > 0.035). Fluid was mildly brighter on intermediate-weighted 2D images (p < 0.001), whereas 3D images had substantially less partial volume, chemical shift and no pulsatile-flow artifacts (p < 0.001). Oblique and curved planar 3D images resulted in mildly-to-substantially improved visualization of joints, spring, bifurcate, syndesmotic, collateral and sinus tarsi ligaments, and tendons (p < 0.001, respectively). 3D TSE MRI with CAIPIRINHA acceleration enables high-spatial resolution oblique and curved planar MRI of the ankle and visualization of ligaments, tendons and joints equally well or better than a more time-consuming anisotropic 2D TSE MRI. (orig.)

  14. CAIPIRINHA accelerated SPACE enables 10-min isotropic 3D TSE MRI of the ankle for optimized visualization of curved and oblique ligaments and tendons

    International Nuclear Information System (INIS)

    Kalia, Vivek; Fritz, Benjamin; Johnson, Rory; Gilson, Wesley D.; Raithel, Esther; Fritz, Jan

    2017-01-01

    To test the hypothesis that a fourfold CAIPIRINHA accelerated, 10-min, high-resolution, isotropic 3D TSE MRI prototype protocol of the ankle derives equal or better quality than a 20-min 2D TSE standard protocol. Following internal review board approval and informed consent, 3-Tesla MRI of the ankle was obtained in 24 asymptomatic subjects including 10-min 3D CAIPIRINHA SPACE TSE prototype and 20-min 2D TSE standard protocols. Outcome variables included image quality and visibility of anatomical structures using 5-point Likert scales. Non-parametric statistical testing was used. P values ≤0.001 were considered significant. Edge sharpness, contrast resolution, uniformity, noise, fat suppression and magic angle effects were without statistical difference on 2D and 3D TSE images (p > 0.035). Fluid was mildly brighter on intermediate-weighted 2D images (p < 0.001), whereas 3D images had substantially less partial volume, chemical shift and no pulsatile-flow artifacts (p < 0.001). Oblique and curved planar 3D images resulted in mildly-to-substantially improved visualization of joints, spring, bifurcate, syndesmotic, collateral and sinus tarsi ligaments, and tendons (p < 0.001, respectively). 3D TSE MRI with CAIPIRINHA acceleration enables high-spatial resolution oblique and curved planar MRI of the ankle and visualization of ligaments, tendons and joints equally well or better than a more time-consuming anisotropic 2D TSE MRI. (orig.)

  15. Elastocapillary fabrication of three-dimensional microstructures

    NARCIS (Netherlands)

    van Honschoten, J.W.; Berenschot, Johan W.; Ondarcuhu, T.; Sanders, Remco G.P.; Sundaram, J.; Elwenspoek, Michael Curt; Tas, Niels Roelof

    2010-01-01

    We describe the fabrication of three-dimensional microstructures by means of capillary forces. Using an origami-like technique, planar silicon nitride structures of various geometries are folded to produce three-dimensional objects of 50–100 m. Capillarity is a particularly effective mechanism since

  16. CAIPIRINHA accelerated SPACE enables 10-min isotropic 3D TSE MRI of the ankle for optimized visualization of curved and oblique ligaments and tendons.

    Science.gov (United States)

    Kalia, Vivek; Fritz, Benjamin; Johnson, Rory; Gilson, Wesley D; Raithel, Esther; Fritz, Jan

    2017-09-01

    To test the hypothesis that a fourfold CAIPIRINHA accelerated, 10-min, high-resolution, isotropic 3D TSE MRI prototype protocol of the ankle derives equal or better quality than a 20-min 2D TSE standard protocol. Following internal review board approval and informed consent, 3-Tesla MRI of the ankle was obtained in 24 asymptomatic subjects including 10-min 3D CAIPIRINHA SPACE TSE prototype and 20-min 2D TSE standard protocols. Outcome variables included image quality and visibility of anatomical structures using 5-point Likert scales. Non-parametric statistical testing was used. P values ≤0.001 were considered significant. Edge sharpness, contrast resolution, uniformity, noise, fat suppression and magic angle effects were without statistical difference on 2D and 3D TSE images (p > 0.035). Fluid was mildly brighter on intermediate-weighted 2D images (p acceleration enables high-spatial resolution oblique and curved planar MRI of the ankle and visualization of ligaments, tendons and joints equally well or better than a more time-consuming anisotropic 2D TSE MRI. • High-resolution 3D TSE MRI improves visualization of ankle structures. • Limitations of current 3D TSE MRI include long scan times. • 3D CAIPIRINHA SPACE allows now a fourfold-accelerated data acquisition. • 3D CAIPIRINHA SPACE enables high-spatial-resolution ankle MRI within 10 min. • 10-min 3D CAIPIRINHA SPACE produces equal-or-better quality than 20-min 2D TSE.

  17. The body force in a three-dimensional Lame system identification and regularization

    DEFF Research Database (Denmark)

    Trong, Dang Duc; Phan, Thanh Nam; Thuc, Phung Trong

    2012-01-01

    Let a three-dimensional isotropic elastic body be described by the Lamé system with the body force of the form F(x, t) = (t)f (x), where is known. We consider the problem of determining the unknown spatial term f (x) of the body force when the surface stress history is given...

  18. Transverse mixing in three-dimensional nonstationary anisotropic heterogeneous porous media

    DEFF Research Database (Denmark)

    Cirpka, Olaf; Chiogna, Gabriele; Rolle, Massimo

    2015-01-01

    -dimensional domains, more complex flow patterns are possible because streamlines can twist. In particular, spatially varying orientation of anisotropy can cause steady-state groundwater whirls. We analyze steady-state solute transport in three-dimensional locally isotropic heterogeneous porous media with blockwise...

  19. On two-dimensionalization of three-dimensional turbulence in shell models

    DEFF Research Database (Denmark)

    Chakraborty, Sagar; Jensen, Mogens Høgh; Sarkar, A.

    2010-01-01

    Applying a modified version of the Gledzer-Ohkitani-Yamada (GOY) shell model, the signatures of so-called two-dimensionalization effect of three-dimensional incompressible, homogeneous, isotropic fully developed unforced turbulence have been studied and reproduced. Within the framework of shell m......-similar PDFs for longitudinal velocity differences are also presented for the rotating 3D turbulence case....

  20. three dimensional photoelastic investigations on thick rectangular

    African Journals Online (AJOL)

    user

    1983-09-01

    Sep 1, 1983 ... Thick rectangular plates are investigated by means of three-dimensional photoelasticity ... a thin plate theory and a higher order thick plate theory. 1. ..... number of fringes lest the accuracy of the results will be considerably.

  1. Three dimensional diffusion calculations of nuclear reactors

    International Nuclear Information System (INIS)

    Caspo, N.

    1981-07-01

    This work deals with the three dimensional calculation of nuclear reactors using the code TRITON. The purposes of the work were to perform three-dimensional computations of the core of the Soreq nuclear reactor and of the power reactor ZION and to validate the TRITON code. Possible applications of the TRITON code in Soreq reactor calculations and in power reactor research are suggested. (H.K.)

  2. Three-dimensional effects in fracture mechanics

    International Nuclear Information System (INIS)

    Benitez, F.G.

    1991-01-01

    An overall view of the pioneering theories and works, which enlighten the three-dimensional nature of fracture mechanics during the last years is given. the main aim is not an exhaustive reviewing but the displaying of the last developments on this scientific field in a natural way. This work attempts to envisage the limits of disregarding the three-dimensional behaviour in theories, analyses and experiments. Moreover, it tries to draw attention on the scant fervour, although increasing, this three-dimensional nature of fracture has among the scientific community. Finally, a constructive discussion is presented on the use of two-dimensional solutions in the analysis of geometries which bear a three-dimensional configuration. the static two-dimensional solutions and its applications fields are reviewed. also, the static three-dimensional solutions, wherein a comparative analysis with elastoplastic and elastostatic solutions are presented. to end up, the dynamic three-dimensional solutions are compared to the asymptotic two-dimensional ones under the practical applications point of view. (author)

  3. Preliminary study of in vivo hemodynamic analysis of intracranial aneurysms using time-resolved three-dimensional phase-contrast MRI and in-house software [Presidential award proceedings

    International Nuclear Information System (INIS)

    Isoda, Haruo; Ohkura, Yasuhide; Seo, Taro

    2007-01-01

    We calculated in vivo wall shear stress (WSS) and streamlines of intracranial aneurysms and analyzed the relationships between the hemodynamics and WSS of the aneurysms using time-resolved three-dimensional (3D) phase-contrast magnetic resonance (MR) imaging (4D-Flow) and in-house software. We studied 10 subjects with 11 aneurysms. 4D-flow was performed using a 1.5T GE MR scanner with head coil. 3D time-of-flight (TOF) MR angiography was performed for geometric information. The software calculated the WSS based on interpolated shearing velocity using the data set obtained by 4D-flow near the wall and provided us with 3D streamlines. We acquired 3D streamlines and WSS distribution maps in arbitrary directions during the cardiac phase for all intracranial aneurysms, and each intracranial aneurysm in this study had at least one spiral flow. We noted lower WSS with lower flow velocities at the apex of the spiral flow. (author)

  4. [Effects of the volume and shape of voxels on the measurement of phantom volume using three-dimensional magnetic resonance imaging].

    Science.gov (United States)

    Mori, Koichi; Hagino, Hirofumi; Saitou, Osamu; Yotsutsuji, Takashi; Tonami, Syuichi; Nakamura, Mamoru; Kuranishi, Makoto

    2002-01-01

    Recently, an increasing number of volumetric studies of the human brain have been reported, using three-dimensional magnetic resonance imaging (3D-MRI). To our knowledge, however, there are few investigations on the relation of the volume and shape of voxels which constitute an MR image to the accuracy in volume measurement of an imaged object. The purpose of this study was to evaluate the effect of a different shape of voxel, that is, isotropic or anisotropic, as well as the volume of a voxel on the volume measurement based on the original image data and multiplanar reconstruction (MPR) data, respectively. In the experiment, we repeatedly acquired contiguous sagittal images of a single globe phantom with a known volume under the condition in which the volume and shape of voxels varied, on a 1.5T MR scanner. We used a gradient echo sequence (3D FLASH). The volume of the globe phantom from both original images and MPR ones was measured on workstations employing a semi-automated local thresholding technique. As a result, the smaller volume of voxels tended to give us the more correct measurement, and an isotropic voxel reduced measurement errors as compared to an anisotropic one. Therefore, it is concluded that the setting of voxel with both an isotropic shape and small volume, e.g., a voxel of 1 mm x 1 mm x 1 mm at present, is recommended in order to get a precise volume measurement using 3D-MRI.

  5. Effects of the volume and shape of voxels on the measurement of phantom volume using three-dimensional magnetic resonance imaging

    International Nuclear Information System (INIS)

    Mori, Koichi; Tonami, Syuichi; Nakamura, Mamoru; Kuranishi, Makoto; Hagino, Hirofumi; Saitou, Osamu; Yotsutsuji, Takashi

    2002-01-01

    Recently, an increasing number of volumetric studies of the human brain have been reported, using three-dimensional magnetic resonance imaging (3D-MRI). To our knowledge, however, there are few investigations on the relation of the volume and shape of voxels which constitute and MR image to the accuracy in volume measurement of an imaged object. The purpose of this study was to evaluate the effect of a different shape of voxel, that is, isotropic or anisotropic, as well as the volume of a voxel on the volume measurement based on the original image data and multiplanar reconstruction (MPR) data, respectively. In the experiment, we repeatedly acquired contiguous sagittal images of a single globe phantom with a known volume under the condition in which the volume and shape of voxels varied, on a 1.5 T MR scanner. We used a gradient echo sequence (3D FLASH). The volume of the globe phantom from both original images and MPR ones was measured on workstations employing a semi-automated local thresholding technique. As a result, the smaller volume of voxels tended to give us the more correct measurement, and an isotropic voxel reduced measurement errors as compared to an anisotropic one. Therefore, it is concluded that the setting of voxel with both an isotropic shape and small volume, e.g., a voxel of 1 mm x 1 mm x 1 mm at present, is recommended in order to get a precise volume measurement using 3D-MRI. (author)

  6. 3T MRI of the knee with optimised isotropic 3D sequences. Accurate delineation of intra-articular pathology without prolonged acquisition times

    Energy Technology Data Exchange (ETDEWEB)

    Abdulaal, Osamah M.; Rainford, Louise; Galligan, Marie; McGee, Allison [University College Dublin, Radiography and Diagnostic Imaging, School of Medicine, Belfield, Dublin (Ireland); MacMahon, Peter; Kavanagh, Eoin [Mater Misericordiae University Hospital, Department of Radiology, Dublin (Ireland); University College Dublin, School of Medicine, Dublin (Ireland); Cashman, James [Mater Misericordiae University Hospital, Department of Orthopaedics, Dublin (Ireland); University College Dublin, School of Medicine, Dublin (Ireland)

    2017-11-15

    To investigate optimised isotropic 3D turbo spin echo (TSE) and gradient echo (GRE)-based pulse sequences for visualisation of articular cartilage lesions within the knee joint. Optimisation of experimental imaging sequences was completed using healthy volunteers (n=16) with a 3-Tesla (3T) MRI scanner. Imaging of patients with knee cartilage abnormalities (n=57) was then performed. Acquired sequences included 3D proton density-weighted (PDW) TSE (SPACE) with and without fat-suppression (FS), and T2*W GRE (TrueFISP) sequences, with acquisition times of 6:51, 6:32 and 5:35 min, respectively. One hundred sixty-one confirmed cartilage lesions were detected and categorised (Grade II n=90, Grade III n=71). The highest sensitivity and specificity for detecting cartilage lesions were obtained with TrueFISP with values of 84.7% and 92%, respectively. Cartilage SNR mean for PDW SPACE-FS was the highest at 72.2. TrueFISP attained the highest CNR means for joint fluid/cartilage (101.5) and joint fluid/ligament (156.5), and the lowest CNR for cartilage/meniscus (48.5). Significant differences were identified across the three sequences for all anatomical structures with respect to SNR and CNR findings (p-value <0.05). Isotropic TrueFISP at 3T, optimised for acquisition time, accurately detects cartilage defects, although it demonstrated the lowest contrast between cartilage and meniscus. (orig.)

  7. Time-efficient, high-resolution, whole brain three-dimensional macromolecular proton fraction mapping.

    Science.gov (United States)

    Yarnykh, Vasily L

    2016-05-01

    Macromolecular proton fraction (MPF) mapping is a quantitative MRI method that reconstructs parametric maps of a relative amount of macromolecular protons causing the magnetization transfer (MT) effect and provides a biomarker of myelination in neural tissues. This study aimed to develop a high-resolution whole brain MPF mapping technique using a minimal number of source images for scan time reduction. The described technique was based on replacement of an actually acquired reference image without MT saturation by a synthetic one reconstructed from R1 and proton density maps, thus requiring only three source images. This approach enabled whole brain three-dimensional MPF mapping with isotropic 1.25 × 1.25 × 1.25 mm(3) voxel size and a scan time of 20 min. The synthetic reference method was validated against standard MPF mapping with acquired reference images based on data from eight healthy subjects. Mean MPF values in segmented white and gray matter appeared in close agreement with no significant bias and small within-subject coefficients of variation (maps demonstrated sharp white-gray matter contrast and clear visualization of anatomical details, including gray matter structures with high iron content. The proposed synthetic reference method improves resolution of MPF mapping and combines accurate MPF measurements with unique neuroanatomical contrast features. © 2015 Wiley Periodicals, Inc.

  8. Three-dimensional microbubble streaming flows

    Science.gov (United States)

    Rallabandi, Bhargav; Marin, Alvaro; Rossi, Massimiliano; Kaehler, Christian; Hilgenfeldt, Sascha

    2014-11-01

    Streaming due to acoustically excited bubbles has been used successfully for applications such as size-sorting, trapping and focusing of particles, as well as fluid mixing. Many of these applications involve the precise control of particle trajectories, typically achieved using cylindrical bubbles, which establish planar flows. Using astigmatic particle tracking velocimetry (APTV), we show that, while this two-dimensional picture is a useful description of the flow over short times, a systematic three-dimensional flow structure is evident over long time scales. We demonstrate that this long-time three-dimensional fluid motion can be understood through asymptotic theory, superimposing secondary axial flows (induced by boundary conditions at the device walls) onto the two-dimensional description. This leads to a general framework that describes three-dimensional flows in confined microstreaming systems, guiding the design of applications that profit from minimizing or maximizing these effects.

  9. Three-dimensional whole-brain perfusion quantification using pseudo-continuous arterial spin labeling MRI at multiple post-labeling delays: accounting for both arterial transit time and impulse response function.

    Science.gov (United States)

    Qin, Qin; Huang, Alan J; Hua, Jun; Desmond, John E; Stevens, Robert D; van Zijl, Peter C M

    2014-02-01

    Measurement of the cerebral blood flow (CBF) with whole-brain coverage is challenging in terms of both acquisition and quantitative analysis. In order to fit arterial spin labeling-based perfusion kinetic curves, an empirical three-parameter model which characterizes the effective impulse response function (IRF) is introduced, which allows the determination of CBF, the arterial transit time (ATT) and T(1,eff). The accuracy and precision of the proposed model were compared with those of more complicated models with four or five parameters through Monte Carlo simulations. Pseudo-continuous arterial spin labeling images were acquired on a clinical 3-T scanner in 10 normal volunteers using a three-dimensional multi-shot gradient and spin echo scheme at multiple post-labeling delays to sample the kinetic curves. Voxel-wise fitting was performed using the three-parameter model and other models that contain two, four or five unknown parameters. For the two-parameter model, T(1,eff) values close to tissue and blood were assumed separately. Standard statistical analysis was conducted to compare these fitting models in various brain regions. The fitted results indicated that: (i) the estimated CBF values using the two-parameter model show appreciable dependence on the assumed T(1,eff) values; (ii) the proposed three-parameter model achieves the optimal balance between the goodness of fit and model complexity when compared among the models with explicit IRF fitting; (iii) both the two-parameter model using fixed blood T1 values for T(1,eff) and the three-parameter model provide reasonable fitting results. Using the proposed three-parameter model, the estimated CBF (46 ± 14 mL/100 g/min) and ATT (1.4 ± 0.3 s) values averaged from different brain regions are close to the literature reports; the estimated T(1,eff) values (1.9 ± 0.4 s) are higher than the tissue T1 values, possibly reflecting a contribution from the microvascular arterial blood compartment

  10. Towards three-dimensional optical metamaterials

    Science.gov (United States)

    Tanaka, Takuo; Ishikawa, Atsushi

    2017-12-01

    Metamaterials have opened up the possibility of unprecedented and fascinating concepts and applications in optics and photonics. Examples include negative refraction, perfect lenses, cloaking, perfect absorbers, and so on. Since these metamaterials are man-made materials composed of sub-wavelength structures, their development strongly depends on the advancement of micro- and nano-fabrication technologies. In particular, the realization of three-dimensional metamaterials is one of the big challenges in this research field. In this review, we describe recent progress in the fabrication technologies for three-dimensional metamaterials, as well as proposed applications.

  11. Development of three dimensional solid modeler

    International Nuclear Information System (INIS)

    Zahoor, R.M.A.

    1999-01-01

    The work presented in this thesis is aimed at developing a three dimensional solid modeler employing computer graphics techniques using C-Language. Primitives have been generated, by combination of plane surfaces, for various basic geometrical shapes including cylinder, cube and cone. Back face removal technique for hidden surface removal has also been incorporated. Various transformation techniques such as scaling, translation, and rotation have been included for the object animation. Three dimensional solid modeler has been created by the union of two primitives to demonstrate the capabilities of the developed program. (author)

  12. Three-dimensional topological insulators and bosonization

    Energy Technology Data Exchange (ETDEWEB)

    Cappelli, Andrea [INFN, Sezione di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Randellini, Enrico [INFN, Sezione di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Dipartimento di Fisica e Astronomia, Università di Firenze,Via G. Sansone 1, 50019 Sesto Fiorentino - Firenze (Italy); Sisti, Jacopo [Scuola Internazionale Superiore di Studi Avanzati (SISSA),Via Bonomea 265, 34136 Trieste (Italy)

    2017-05-25

    Massless excitations at the surface of three-dimensional time-reversal invariant topological insulators possess both fermionic and bosonic descriptions, originating from band theory and hydrodynamic BF theory, respectively. We analyze the corresponding field theories of the Dirac fermion and compactified boson and compute their partition functions on the three-dimensional torus geometry. We then find some non-dynamic exact properties of bosonization in (2+1) dimensions, regarding fermion parity and spin sectors. Using these results, we extend the Fu-Kane-Mele stability argument to fractional topological insulators in three dimensions.

  13. Three-dimensional imaging utilizing energy discrimination

    International Nuclear Information System (INIS)

    Gunter, D.L.; Hoffman, K.R.; Beck, R.N.

    1990-01-01

    An algorithm is proposed for three-dimensional image reconstruction in nuclear medicine which uses scattered radiation rather than multiple projected images to determine the source depth within the body. Images taken from numerous energy windows are combined to construct the source distribution in the body. The gamma-ray camera is not moved during the imaging process. Experiments with both Tc-99m and Ga-67 demonstrate that two channels of depth information can be extracted from the low energy images produced by scattered radiation. By combining this technique with standard SPECT reconstruction using multiple projections the authors anticipate much improved spatial resolution in the overall three-dimensional reconstruction

  14. Creation of three-dimensional craniofacial standards from CBCT images

    Science.gov (United States)

    Subramanyan, Krishna; Palomo, Martin; Hans, Mark

    2006-03-01

    Low-dose three-dimensional Cone Beam Computed Tomography (CBCT) is becoming increasingly popular in the clinical practice of dental medicine. Two-dimensional Bolton Standards of dentofacial development are routinely used to identify deviations from normal craniofacial anatomy. With the advent of CBCT three dimensional imaging, we propose a set of methods to extend these 2D Bolton Standards to anatomically correct surface based 3D standards to allow analysis of morphometric changes seen in craniofacial complex. To create 3D surface standards, we have implemented series of steps. 1) Converting bi-plane 2D tracings into set of splines 2) Converting the 2D splines curves from bi-plane projection into 3D space curves 3) Creating labeled template of facial and skeletal shapes and 4) Creating 3D average surface Bolton standards. We have used datasets from patients scanned with Hitachi MercuRay CBCT scanner providing high resolution and isotropic CT volume images, digitized Bolton Standards from age 3 to 18 years of lateral and frontal male, female and average tracings and converted them into facial and skeletal 3D space curves. This new 3D standard will help in assessing shape variations due to aging in young population and provide reference to correct facial anomalies in dental medicine.

  15. Dose response study of PVA-Fx gel for three dimensional dose distribution

    International Nuclear Information System (INIS)

    Brindha, S.; Ayyangar, Komanduri M.; Shen, Bin; Saw, Cheng B.

    2001-01-01

    Modern radiotherapy techniques involve complex field arrangements using conformal and intensity modulated radiation that requires three dimensional treatment planning. The verification of these plans poses even more challenge. In 1984, Gore et al., proposed that ferrous gel dosimeters combined with magnetic resonance imaging (MRI) could be used to measure three dimensional radiation dose distributions. Since then, there has been much interest in the development of gel dosimetry to aid the determination of three dimensional dose distributions during field arrangements. In this work, preparation and study of the MR characteristics of a PVA-Fx gel reported in the literature is presented

  16. Three-Dimensional Messages for Interstellar Communication

    Science.gov (United States)

    Vakoch, Douglas A.

    One of the challenges facing independently evolved civilizations separated by interstellar distances is to communicate information unique to one civilization. One commonly proposed solution is to begin with two-dimensional pictorial representations of mathematical concepts and physical objects, in the hope that this will provide a foundation for overcoming linguistic barriers. However, significant aspects of such representations are highly conventional, and may not be readily intelligible to a civilization with different conventions. The process of teaching conventions of representation may be facilitated by the use of three-dimensional representations redundantly encoded in multiple formats (e.g., as both vectors and as rasters). After having illustrated specific conventions for representing mathematical objects in a three-dimensional space, this method can be used to describe a physical environment shared by transmitter and receiver: a three-dimensional space defined by the transmitter--receiver axis, and containing stars within that space. This method can be extended to show three-dimensional representations varying over time. Having clarified conventions for representing objects potentially familiar to both sender and receiver, novel objects can subsequently be depicted. This is illustrated through sequences showing interactions between human beings, which provide information about human behavior and personality. Extensions of this method may allow the communication of such culture-specific features as aesthetic judgments and religious beliefs. Limitations of this approach will be noted, with specific reference to ETI who are not primarily visual.

  17. Three-Dimensional Printing Surgical Applications.

    Science.gov (United States)

    AlAli, Ahmad B; Griffin, Michelle F; Butler, Peter E

    2015-01-01

    Three-dimensional printing, a technology used for decades in the industrial field, gains a lot of attention in the medical field for its potential benefits. With advancement of desktop printers, this technology is accessible and a lot of research is going on in the medical field. To evaluate its application in surgical field, which may include but not limited to surgical planning, surgical education, implants, and prosthesis, which are the focus of this review. Research was conducted by searching PubMed, Web of science, and other reliable sources. We included original articles and excluded articles based on animals, those more than 10 years old, and those not in English. These articles were evaluated, and relevant studies were included in this review. Three-dimensional printing shows a potential benefit in surgical application. Printed implants were used in patient in a few cases and show successful results; however, longer follow-up and more trials are needed. Surgical and medical education is believed to be more efficient with this technology than the current practice. Printed surgical instrument and surgical planning are also believed to improve with three-dimensional printing. Three-dimensional printing can be a very powerful tool in the near future, which can aid the medical field that is facing a lot of challenges and obstacles. However, despite the reported results, further research on larger samples and analytical measurements should be conducted to ensure this technology's impact on the practice.

  18. Electron crystallography of three dimensional protein crystals

    NARCIS (Netherlands)

    Georgieva, Dilyana

    2008-01-01

    This thesis describes an investigation of the potential of electron diffraction for studying three dimensional sub-micro-crystals of proteins and pharmaceuticals. A prerequisite for using electron diffraction for structural studies is the predictable availability of tiny crystals. A method for

  19. Three dimensional electrochemical system for neurobiological studies

    DEFF Research Database (Denmark)

    Vazquez, Patricia; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    In this work we report a novel three dimensional electrode array for electrochemical measurements in neuronal studies. The main advantage of working with these out-of-plane structures is the enhanced sensitivity of the system in terms of measuring electrochemical changes in the environment...

  20. Imaging unsteady three-dimensional transport phenomena

    Indian Academy of Sciences (India)

    2014-01-05

    Jan 5, 2014 ... The image data can be jointly analysed with the physical laws governing transport and principles of image formation. Hence, with the experiment suitably carried out, three-dimensional physical domains with unsteady processes can be accommodated. Optical methods promise to breach the holy grail of ...

  1. Computerized three-dimensional normal atlas

    International Nuclear Information System (INIS)

    Mano, Isamu; Suto, Yasuzo; Suzuki, Masataka; Iio, Masahiro.

    1990-01-01

    This paper presents our ongoing project in which normal human anatomy and its quantitative data are systematically arranged in a computer. The final product, the Computerized Three-Dimensional Normal Atlas, will be able to supply tomographic images in any direction, 3-D images, and coded information on organs, e.g., anatomical names, CT numbers, and T 1 and T 2 values. (author)

  2. Three-Dimensional Shallow Water Acoustics

    Science.gov (United States)

    2016-03-30

    medium properties, so horizontal refraction and reflection of sound can occur and produce significant three-dimensional (3-D) sound propagation ...by the environmental factors existing commonly in the continental shelf and shelfbreak areas, such as slopes, submarine canyons, sub-bottom layers ...surface waves, internal waves and shelfbreak fronts. 15. SUBJECT TERMS Continental Shelf; 3-D Acoustics , Surface Waves, Sound Propagation 16

  3. Arching in three-dimensional clogging

    Science.gov (United States)

    Török, János; Lévay, Sára; Szabó, Balázs; Somfai, Ellák; Wegner, Sandra; Stannarius, Ralf; Börzsönyi, Tamás

    2017-06-01

    Arching in dry granular material is a long established concept, however it remains still an open question how three-dimensional orifices clog. We investigate by means of numerical simulations and experimental data how the outflow creates a blocked configuration of particles. We define the concave surface of the clogged dome by two independent methods (geometric and density based). The average shape of the cupola for spheres is almost a hemisphere but individual samples have large holes in the structure indicating a blocked state composed of two-dimensional force chains rather than three-dimensional objects. The force chain structure justifies this assumption. For long particles the clogged configurations display large variations, and in certain cases the empty region reaches a height of 5 hole diameters. These structures involve vertical walls consisting of horizontally placed stable stacking of particles.

  4. Three-dimensional bio-printing.

    Science.gov (United States)

    Gu, Qi; Hao, Jie; Lu, YangJie; Wang, Liu; Wallace, Gordon G; Zhou, Qi

    2015-05-01

    Three-dimensional (3D) printing technology has been widely used in various manufacturing operations including automotive, defence and space industries. 3D printing has the advantages of personalization, flexibility and high resolution, and is therefore becoming increasingly visible in the high-tech fields. Three-dimensional bio-printing technology also holds promise for future use in medical applications. At present 3D bio-printing is mainly used for simulating and reconstructing some hard tissues or for preparing drug-delivery systems in the medical area. The fabrication of 3D structures with living cells and bioactive moieties spatially distributed throughout will be realisable. Fabrication of complex tissues and organs is still at the exploratory stage. This review summarize the development of 3D bio-printing and its potential in medical applications, as well as discussing the current challenges faced by 3D bio-printing.

  5. Three dimensional imaging in cardiac nuclear medicine

    International Nuclear Information System (INIS)

    Torizuka, Kanji; Ishii, Yasushi; Yonekura, Yoshiharu; Yamamoto, Kazutaka; Tamaki, Takeyoshi

    1981-01-01

    Methods to obtain three dimensional images of the heart were reviewed. Gated three dimensional display reconstructed from images using bidirectional collimator, was a useful method to detect akinesis of the heart wall. Tomographic observation of the heart can be carried out by a pinhole collimator to image ischemia with high sensitivity. However the focusing plane must be carefully selected to prevent false positives. In the case of emission CT (ECT), utilization of positron emitters gave a quantitative image without correction, whereas single photon ECT needed the correction due to the absorption of γ-ray. Though the reliability of the images by ECT was high, the time required for data acquisition was much longer than that by a 7 pinhole or bidirectional collimator. (Nakanishi, T.)

  6. Three dimensional transport model for toroidal plasmas

    International Nuclear Information System (INIS)

    Copenhauer, C.

    1980-12-01

    A nonlinear MHD model, developed for three-dimensional toroidal geometries (asymmetric) and for high β (β approximately epsilon), is used as a basis for a three-dimensional transport model. Since inertia terms are needed in describing evolving magnetic islands, the model can calculate transport, both in the transient phase before nonlinear saturation of magnetic islands and afterwards on the resistive time scale. In the β approximately epsilon ordering, the plasma does not have sufficient energy to compress the parallel magnetic field, which allows the Alfven wave to be eliminated in the reduced nonlinear equations, and the model then follows the slower time scales. The resulting perpendicular and parallel plasma drift velocities can be identified with those of guiding center theory

  7. Three dimensional digital imaging of environmental data

    International Nuclear Information System (INIS)

    Nichols, R.L.; Eddy, C.A.

    1991-01-01

    The Environmental Sciences Section (ESS) of the Savannah River Laboratory has recently acquired the computer hardware (Silicon Graphics Personal Iris Workstations) and software (Dynamic Graphics, Interactive Surface and Volume Modeling) to perform three dimensional analysis of hydrogeologic data. Three dimensional digital imaging of environmental data is a powerful technique that can be used to incorporate field, analytical, and modeling results from geologic, hydrologic, ecologic, and chemical studies into a comprehensive model for visualization and interpretation. This report covers the contamination of four different sites of the Savannah River Plant. Each section of this report has a computer graphic display of the concentration of contamination in the groundwater and/or sediments of each site

  8. SNAP - a three dimensional neutron diffusion code

    International Nuclear Information System (INIS)

    McCallien, C.W.J.

    1993-02-01

    This report describes a one- two- three-dimensional multi-group diffusion code, SNAP, which is primarily intended for neutron diffusion calculations but can also carry out gamma calculations if the diffusion approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. SNAP can solve the multi-group neutron diffusion equations using finite difference methods. The one-dimensional slab, cylindrical and spherical geometries and the two-dimensional case are all treated as simple special cases of three-dimensional geometries. Numerous reflective and periodic symmetry options are available and may be used to reduce the number of mesh points necessary to represent the system. Extrapolation lengths can be specified at internal and external boundaries. (Author)

  9. Three-dimensional Imaging, Visualization, and Display

    CERN Document Server

    Javidi, Bahram; Son, Jung-Young

    2009-01-01

    Three-Dimensional Imaging, Visualization, and Display describes recent developments, as well as the prospects and challenges facing 3D imaging, visualization, and display systems and devices. With the rapid advances in electronics, hardware, and software, 3D imaging techniques can now be implemented with commercially available components and can be used for many applications. This volume discusses the state-of-the-art in 3D display and visualization technologies, including binocular, multi-view, holographic, and image reproduction and capture techniques. It also covers 3D optical systems, 3D display instruments, 3D imaging applications, and details several attractive methods for producing 3D moving pictures. This book integrates the background material with new advances and applications in the field, and the available online supplement will include full color videos of 3D display systems. Three-Dimensional Imaging, Visualization, and Display is suitable for electrical engineers, computer scientists, optical e...

  10. Three-dimensional imaging modalities in endodontics

    Science.gov (United States)

    Mao, Teresa

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome. PMID:25279337

  11. Three-dimensional imaging modalities in endodontics

    Energy Technology Data Exchange (ETDEWEB)

    Mao, Teresa; Neelakantan, Prasanna [Dept. of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha University, Chennai (India)

    2014-09-15

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome.

  12. Three-dimensional imaging modalities in endodontics

    International Nuclear Information System (INIS)

    Mao, Teresa; Neelakantan, Prasanna

    2014-01-01

    Recent research in endodontics has highlighted the need for three-dimensional imaging in the clinical arena as well as in research. Three-dimensional imaging using computed tomography (CT) has been used in endodontics over the past decade. Three types of CT scans have been studied in endodontics, namely cone-beam CT, spiral CT, and peripheral quantitative CT. Contemporary endodontics places an emphasis on the use of cone-beam CT for an accurate diagnosis of parameters that cannot be visualized on a two-dimensional image. This review discusses the role of CT in endodontics, pertaining to its importance in the diagnosis of root canal anatomy, detection of peri-radicular lesions, diagnosis of trauma and resorption, presurgical assessment, and evaluation of the treatment outcome

  13. THREE DIMENSIONAL GRAPHICAL REPRESENTATION OF QUALITY

    Directory of Open Access Journals (Sweden)

    Vineet V. Kumar

    2014-03-01

    Full Text Available Quality is an important aspect for every firm in modern era of competition. Every product has tough competition in terms of market reach. The factor, which actually makes any product long run in market, is quality and hence quality is the stepping-stone for success of any firm. For everyone meaning of quality is different. We have seen several economists who have defined quality by considering different factors, but what all of them have common in them is Customer satisfaction. Customer satisfaction is the ultimate result of quality. In three-dimensional graphical representation of quality, optimum quality is obtained by using three-dimensional graph by considering some important factors governing quality of any product, limiting factor, and customer satisfaction.

  14. Three dimensional contact/impact methodology

    International Nuclear Information System (INIS)

    Kulak, R.F.

    1987-01-01

    The simulation of three-dimensional interface mechanics between reactor components and structures during static contact or dynamic impact is necessary to realistically evaluate their structural integrity to off-normal loads. In our studies of postulated core energy release events, we have found that significant structure-structure interactions occur in some reactor vessel head closure designs and that fluid-structure interactions occur within the reactor vessel. Other examples in which three-dimensional interface mechanics play an important role are: (1) impact response of shipping casks containing spent fuel, (2) whipping pipe impact on reinforced concrete panels or pipe-to-pipe impact after a pipe break, (3) aircraft crash on secondary containment structures, (4) missiles generated by turbine failures or tornados, and (5) drops of heavy components due to lifting accidents. The above is a partial list of reactor safety problems that require adequate treatment of interface mechanics and are discussed in this paper

  15. A pilot study of three dimensional color CT images of brain diseases to improve informed consent

    International Nuclear Information System (INIS)

    Tanizaki, Yoshio; Akiyama, Takenori; Hiraga, Kenji; Akaji, Kazunori

    2005-01-01

    We have described brain diseases to patients and their family using monochrome CT images. It is thought that patients have difficulties in giving their consent to our conventional explanation because their understanding of brain diseases is based on three dimensional and color images, however, standard CT images are two dimensional and gray scale images. We have been trying to use three dimensional color CT images to improve the typical patient's comprehension of brain diseases. We also try to simulate surgery using these images. Multi-slice CT accumulates precise isotropic voxel data within a half minute. These two dimensional and monochrome data are converted to three dimensional color CT images by 3D workstation. Three dimensional color CT images of each brain structures (e.g. scalp, skull, brain, ventricles and lesions) are created separately. Then, selected structures are fused together for different purposes. These images are able to rotate around any axis. Because the methods to generate three-dimensional color images have not established, we neurosurgeons must create these images. In particular, when an operation is required, the surgeon should create the images. In this paper, we demonstrate how three-dimensional color CT images can improve informed consent. (author)

  16. Three-dimensional simulation of vortex breakdown

    Science.gov (United States)

    Kuruvila, G.; Salas, M. D.

    1990-01-01

    The integral form of the complete, unsteady, compressible, three-dimensional Navier-Stokes equations in the conservation form, cast in generalized coordinate system, are solved, numerically, to simulate the vortex breakdown phenomenon. The inviscid fluxes are discretized using Roe's upwind-biased flux-difference splitting scheme and the viscous fluxes are discretized using central differencing. Time integration is performed using a backward Euler ADI (alternating direction implicit) scheme. A full approximation multigrid is used to accelerate the convergence to steady state.

  17. Impermeability effects in three-dimensional vesicles

    International Nuclear Information System (INIS)

    Biscari, P; Canevese, S M; Napoli, G

    2004-01-01

    We analyse the effects of the impermeability constraint on the equilibrium shapes of a three-dimensional vesicle hosting a rigid inclusion. A given alteration of the inclusion and/or vesicle parameters leads to shape modifications of different orders of magnitude, when applied to permeable or impermeable vesicles. Moreover, the enclosed-volume constraint wrecks the uniqueness of stationary equilibrium shapes, and gives rise to pear-shaped or stomatocyte-like vesicles

  18. Applicability of three-dimensional imaging techniques in fetal medicine

    Energy Technology Data Exchange (ETDEWEB)

    Werner Junior, Heron; Daltro, Pedro; Gasparetto, Emerson Leandro, E-mail: heronwerner@hotmail.com [Clinica de Diagnostico Por Imagem (CDPI), Rio de Janeiro, RJ (Brazil); Santos, Jorge Lopes dos; Belmonte, Simone; Ribeiro, Gerson [Pontificia Universidade Catolica do Rio de Janeiro (PUC-Rio), RJ (Brazil); Marchiori, Edson [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2016-09-15

    Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. (author)

  19. Applicability of three-dimensional imaging techniques in fetal medicine*

    Science.gov (United States)

    Werner Júnior, Heron; dos Santos, Jorge Lopes; Belmonte, Simone; Ribeiro, Gerson; Daltro, Pedro; Gasparetto, Emerson Leandro; Marchiori, Edson

    2016-01-01

    Objective To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models. PMID:27818540

  20. Multiparallel Three-Dimensional Optical Microscopy

    Science.gov (United States)

    Nguyen, Lam K.; Price, Jeffrey H.; Kellner, Albert L.; Bravo-Zanoquera, Miguel

    2010-01-01

    Multiparallel three-dimensional optical microscopy is a method of forming an approximate three-dimensional image of a microscope sample as a collection of images from different depths through the sample. The imaging apparatus includes a single microscope plus an assembly of beam splitters and mirrors that divide the output of the microscope into multiple channels. An imaging array of photodetectors in each channel is located at a different distance along the optical path from the microscope, corresponding to a focal plane at a different depth within the sample. The optical path leading to each photodetector array also includes lenses to compensate for the variation of magnification with distance so that the images ultimately formed on all the photodetector arrays are of the same magnification. The use of optical components common to multiple channels in a simple geometry makes it possible to obtain high light-transmission efficiency with an optically and mechanically simple assembly. In addition, because images can be read out simultaneously from all the photodetector arrays, the apparatus can support three-dimensional imaging at a high scanning rate.

  1. Three dimensional analysis of laterally loaded piles

    International Nuclear Information System (INIS)

    Yilmaz, C.

    1987-01-01

    In this study static analysis of laterally loaded pile is studied by the three models. The first model is the beam on discrete elastic springs. This model is analyzed using a flexibility method. The second model is the beam on a two-parameter elastic foundation. This model is analyzed using the linear finite element method. The third model is the finite element model, using the three-dimensional iso-parametric parabolic brick element. Three-dimensional pile group analysis is also performed using elastic constants of single pile obtained by any one of the above analyses. The main objective is to develop computer programs for each model related to single piles and to group analysis. Then, the deflections, rotations, moments, shears, stresses and strains of the single pile are obtained at any arbitrary point. Comparison is made between each model and with other studies such as Poulos 1971, Desai and Appel 1976. In addition, to provide a benchmark of three-dimensional finite element analysis, the Boussinesq problem is analyzed. (orig.)

  2. Three-Dimensional Reconstruction of Sandpile Interiors

    Science.gov (United States)

    Seidler, G. T.

    2001-03-01

    The granular bed, or sandpile, has become one of the condensed matter physicist's favorite systems. In addition to conceptual appeal, the simplest sandpile of monodisperse hard spheres is a valuable model system for understanding powders, liquids, and metallic glasses. Any fundamental approach to the transport and mechanical properties of three-dimensional mesoscale disordered materials must follow from a thorough understanding of their structure. However, in the overwhelming majority of cases, structure measurements have been limited to the mean filling fraction and the structural autocorrelation function. This is particularly unfortunate in the ongoing sandpile renaissance, where some of the most interesting questions concern structure and the relationship between structure and dynamics. I will discuss the combination of synchrotron x-ray microtomography and computer vision algorithms to perform three-dimensional virtual reconstructions of real sandpiles. This technique is rapid and noninvasive, and is applicable to samples large enough to separate bulk and boundary properties. The resulting complete knowledge of structure can be used to calculate otherwise inaccessible correlation functions. I will present results for several measures of the bond-orientational order in three-dimensional sandpiles, including fabric tensors and nematic order parameters.

  3. Three-dimensional deformation of orthodontic brackets

    Science.gov (United States)

    Melenka, Garrett W; Nobes, David S; Major, Paul W

    2013-01-01

    Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire–bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design. PMID:23762201

  4. Three-dimensional deformation of orthodontic brackets.

    Science.gov (United States)

    Melenka, Garrett W; Nobes, David S; Major, Paul W; Carey, Jason P

    2013-01-01

    Braces are used by orthodontists to correct the misalignment of teeth in the mouth. Archwire rotation is a particular procedure used to correct tooth inclination. Wire rotation can result in deformation to the orthodontic brackets, and an orthodontic torque simulator has been designed to examine this wire-bracket interaction. An optical technique has been employed to measure the deformation due to size and geometric constraints of the orthodontic brackets. Images of orthodontic brackets are collected using a stereo microscope and two charge-coupled device cameras, and deformation of orthodontic brackets is measured using a three-dimensional digital image correlation technique. The three-dimensional deformation of orthodontic brackets will be evaluated. The repeatability of the three-dimensional digital image correlation measurement method was evaluated by performing 30 archwire rotation tests using the same bracket and archwire. Finally, five Damon 3MX and five In-Ovation R self-ligating brackets will be compared using this technique to demonstrate the effect of archwire rotation on bracket design.

  5. Three dimensional illustrating - three-dimensional vision and deception of sensibility

    Directory of Open Access Journals (Sweden)

    Anita Gánóczy

    2009-03-01

    Full Text Available The wide-spread digital photography and computer use gave the opportunity for everyone to make three-dimensional pictures and to make them public. The new opportunities with three-dimensional techniques give chance for the birth of new artistic photographs. We present in detail the biological roots of three-dimensional visualization, the phenomena of movement parallax, which can be used efficiently in making three-dimensional graphics, the Zöllner- and Corridor-illusion. There are present in this paper the visual elements, which contribute to define a plane two-dimensional image in three-dimension: coherent lines, the covering, the measurement changes, the relative altitude state, the abatement of detail profusion, the shadings and the perspective effects of colors.

  6. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    International Nuclear Information System (INIS)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu

    1989-01-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.)

  7. Three-dimensional analysis of craniofacial bones using three-dimensional computer tomography

    Energy Technology Data Exchange (ETDEWEB)

    Ono, Ichiro; Ohura, Takehiko; Kimura, Chu (Hokkaido Univ., Sapporo (Japan). School of Medicine) (and others)

    1989-08-01

    Three-dimensional computer tomography (3DCT) was performed in patients with various diseases to visualize stereoscopically the deformity of the craniofacial bones. The data obtained were analyzed by the 3DCT analyzing system. A new coordinate system was established using the median sagittal plane of the face (a plane passing through sella, nasion and basion) on the three-dimensional image. Three-dimensional profilograms were prepared for detailed analysis of the deformation of craniofacial bones for cleft lip and palate, mandibular prognathia and hemifacial microsomia. For patients, asymmetry in the frontal view and twist-formed complicated deformities were observed, as well as deformity of profiles in the anteroposterior and up-and-down directions. A newly developed technique allows three-dimensional visualization of changes in craniofacial deformity. It would aid in determining surgical strategy, including crani-facial surgery and maxillo-facial surgery, and in evaluating surgical outcome. (N.K.).

  8. Three-dimensional instability of standing waves

    Science.gov (United States)

    Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

    2003-12-01

    We investigate the three-dimensional instability of finite-amplitude standing surface waves under the influence of gravity. The analysis employs the transition matrix (TM) approach and uses a new high-order spectral element (HOSE) method for computation of the nonlinear wave dynamics. HOSE is an extension of the original high-order spectral method (HOS) wherein nonlinear wave wave and wave body interactions are retained up to high order in wave steepness. Instead of global basis functions in HOS, however, HOSE employs spectral elements to allow for complex free-surface geometries and surface-piercing bodies. Exponential convergence of HOS with respect to the total number of spectral modes (for a fixed number of elements) and interaction order is retained in HOSE. In this study, we use TM-HOSE to obtain the stability of general three-dimensional perturbations (on a two-dimensional surface) on two classes of standing waves: plane standing waves in a rectangular tank; and radial/azimuthal standing waves in a circular basin. For plane standing waves, we confirm the known result of two-dimensional side-bandlike instability. In addition, we find a novel three-dimensional instability for base flow of any amplitude. The dominant component of the unstable disturbance is an oblique (standing) wave oriented at an arbitrary angle whose frequency is close to the (nonlinear) frequency of the original standing wave. This finding is confirmed by direct long-time simulations using HOSE which show that the nonlinear evolution leads to classical Fermi Pasta Ulam recurrence. For the circular basin, we find that, beyond a threshold wave steepness, a standing wave (of nonlinear frequency Omega) is unstable to three-dimensional perturbations. The unstable perturbation contains two dominant (standing-wave) components, the sum of whose frequencies is close to 2Omega. From the cases we consider, the critical wave steepness is found to generally decrease/increase with increasing radial

  9. Isotropic Negative Thermal Expansion Metamaterials.

    Science.gov (United States)

    Wu, Lingling; Li, Bo; Zhou, Ji

    2016-07-13

    Negative thermal expansion materials are important and desirable in science and engineering applications. However, natural materials with isotropic negative thermal expansion are rare and usually unsatisfied in performance. Here, we propose a novel method to achieve two- and three-dimensional negative thermal expansion metamaterials via antichiral structures. The two-dimensional metamaterial is constructed with unit cells that combine bimaterial strips and antichiral structures, while the three-dimensional metamaterial is fabricated by a multimaterial 3D printing process. Both experimental and simulation results display isotropic negative thermal expansion property of the samples. The effective coefficient of negative thermal expansion of the proposed models is demonstrated to be dependent on the difference between the thermal expansion coefficient of the component materials, as well as on the circular node radius and the ligament length in the antichiral structures. The measured value of the linear negative thermal expansion coefficient of the three-dimensional sample is among the largest achieved in experiments to date. Our findings provide an easy and practical approach to obtaining materials with tunable negative thermal expansion on any scale.

  10. Three-dimensional stereo by photometric ratios

    International Nuclear Information System (INIS)

    Wolff, L.B.; Angelopoulou, E.

    1994-01-01

    We present a methodology for corresponding a dense set of points on an object surface from photometric values for three-dimensional stereo computation of depth. The methodology utilizes multiple stereo pairs of images, with each stereo pair being taken of the identical scene but under different illumination. With just two stereo pairs of images taken under two different illumination conditions, a stereo pair of ratio images can be produced, one for the ratio of left-hand images and one for the ratio of right-hand images. We demonstrate how the photometric ratios composing these images can be used for accurate correspondence of object points. Object points having the same photometric ratio with respect to two different illumination conditions constitute a well-defined equivalence class of physical constraints defined by local surface orientation relative to illumination conditions. We formally show that for diffuse reflection the photometric ratio is invariant to varying camera characteristics, surface albedo, and viewpoint and that therefore the same photometric ratio in both images of a stereo pair implies the same equivalence class of physical constraints. The correspondence of photometric ratios along epipolar lines in a stereo pair of images under different illumination conditions is a correspondence of equivalent physical constraints, and the determination of depth from stereo can be performed. Whereas illumination planning is required, our photometric-based stereo methodology does not require knowledge of illumination conditions in the actual computation of three-dimensional depth and is applicable to perspective views. This technique extends the stereo determination of three-dimensional depth to smooth featureless surfaces without the use of precisely calibrated lighting. We demonstrate experimental depth maps from a dense set of points on smooth objects of known ground-truth shape, determined to within 1% depth accuracy

  11. Three-dimensional CT of the mandible

    International Nuclear Information System (INIS)

    Zinreich, S.J.; Price, J.C.; Wang, H.; Ahn, H.S.; Kashima, H.

    1988-01-01

    Seventeen patients with mandibular oblation for facial neoplasia, primary neoplasm, and trauma were evaluated with CT and three-dimensional CT. In eight of these patients, a computerized acrylic model was generated for preoperative planning and postoperative reconstruction. The ramus and body of the mandible were reconstructed with mirror image and fusion techniques. Reconstructions of the anterior mandible were generated from models including the midface, skull based, and residual mandibular fragments. The results are preliminary; however, the authors believe that these represent a powerful new tool and a significant advance in mandibular reconstructive technique, reduced anesthesia time, and the optimized restoration of dental alignment and facial contour

  12. Three-dimensional interpretation of TEM soundings

    Science.gov (United States)

    Barsukov, P. O.; Fainberg, E. B.

    2013-07-01

    We describe the approach to the interpretation of electromagnetic (EM) sounding data which iteratively adjusts the three-dimensional (3D) model of the environment by local one-dimensional (1D) transformations and inversions and reconstructs the geometrical skeleton of the model. The final 3D inversion is carried out with the minimal number of the sought parameters. At each step of the interpretation, the model of the medium is corrected according to the geological information. The practical examples of the suggested method are presented.

  13. Three Dimensional Double Layers in Magnetized Plasmas

    DEFF Research Database (Denmark)

    Jovanovic, D.; Lynov, Jens-Peter; Michelsen, Poul

    1982-01-01

    Experimental results are presented which demonstrate the formation of fully three dimensional double layers in a magnetized plasma. The measurements are performed in a magnetized stationary plasma column with radius 1.5 cm. Double layers are produced by introducing an electron beam with radius 0.......4 cm along the magnetic field from one end of the column. The voltage drop across the double layer is found to be determined by the energy of the incoming electron beam. In general we find that the width of the double layer along the external magnetic field is determined by plasma density and beam...

  14. Three-dimensional flow about penguin wings

    Science.gov (United States)

    Noca, Flavio; Sudki, Bassem; Lauria, Michel

    2012-11-01

    Penguins, contrary to airborne birds, do not need to compensate for gravity. Yet, the kinematics of their wings is highly three-dimensional and seems exceedingly complex for plain swimming. Is such kinematics the result of an evolutionary optimization or is it just a forced adaptation of an airborne flying apparatus to underwater swimming? Some answers will be provided based on flow dynamics around robotic penguin wings. Updates will also be presented on the development of a novel robotic arm intended to simulate penguin swimming and enable novel propulsion devices.

  15. Three-dimensional teletherapy treatment planning

    International Nuclear Information System (INIS)

    Panthaleon van Eck, R.B. van.

    1986-01-01

    This thesis deals with physical/mathematical backgrounds of computerized teletherapy treatment planning. The subjects discussed in this thesis can be subdivided into three main categories: a) Three-dimensional treatment planning. A method is evaluated which can be used for the purpose of simulation and optimization of dose distributions in three dimensions. b) The use of Computed Tomography. The use of patient information obtained from Computed Tomography for the purpose of dose computations is evaluated. c) Dose computational models for photon- and electron beams. Models are evaluated which provide information regarding the way in which the radiation dose is distributed in the patient (viz. is absorbed and/or dispersed). (Auth.)

  16. Creating three-dimensional thermal maps

    CSIR Research Space (South Africa)

    Price

    2011-11-01

    Full Text Available stream_source_info Price_2011.pdf.txt stream_content_type text/plain stream_size 30895 Content-Encoding ISO-8859-1 stream_name Price_2011.pdf.txt Content-Type text/plain; charset=ISO-8859-1 Creating Three...-Dimensional Thermal Maps Mathew Price Cogency cc Cape Town Email: mathew@cogency.co.za Jeremy Green CSIR Centre for Mining Innovation Johannesburg Email: jgreen@csir.co.za John Dickens CSIR Centre for Mining Innovation Johannesburg Email: jdickens...

  17. Three-dimensional cooling of muons

    CERN Document Server

    Vsevolozhskaya, T A

    2000-01-01

    The simultaneous ionization cooling of muon beams in all three - the longitudinal and two transverse - directions is considered in a scheme, based on bent lithium lenses with dipole constituent of magnetic field in them, created by a special configuration of current-carrying rod. An analysis of three-dimensional cooling is performed with the use of kinetic equation method. Results of numerical calculation for a specific beam line configuration are presented together with results of computer simulation using the Moliere distribution to describe the Coulomb scattering and the Vavilov distribution used to describe the ionization loss of energy.

  18. The future of three-dimensional medical imaging

    International Nuclear Information System (INIS)

    Peter, T.M.

    1996-01-01

    The past 15 years have witnessed an explosion in medical imaging technology, and none more so than in the tomographic imaging modalities of CT and MRI. Prior to 1975, 3-D imaging was largely performed in the minds of radiologists and surgeons, assisted by the modalities of conventional x-ray tomography and stereoscopic radiography. However today, with the advent of imaging techniques which ower their existence to computer technology, three-dimensional image acquisition is fast becoming the norm and the clinician finally has access to sets of data that represent the entire imaged volume. Stereoscopic image visualization has already begun to reappear as a viable means of visualizing 3 D medical images. The future of 3-D imaging is exciting and will undoubtedly move further in the direction of virtual reality. (author)

  19. Three-dimensional radiation treatment planning

    International Nuclear Information System (INIS)

    Mohan, R.

    1989-01-01

    A major aim of radiation therapy is to deliver sufficient dose to the tumour volume to kill the cancer cells while sparing the nearby health organs to prevent complications. With the introduction of devices such as CT and MR scanners, radiation therapy treatment planners have access to full three-dimensional anatomical information to define, simulate, and evaluate treatments. There are a limited number of prototype software systems that allow 3D treatment planning currently in use. In addition, there are more advanced tools under development or still in the planning stages. They require sophisticated graphics and computation equipment, complex physical and mathematical algorithms, and new radiation treatment machines that deliver dose very precisely under computer control. Components of these systems include programs for the identification and delineation of the anatomy and tumour, the definition of radiation beams, the calculation of dose distribution patterns, the display of dose on 2D images and as three dimensional surfaces, and the generation of computer images to verify proper patient positioning in treatment. Some of these functions can be performed more quickly and accurately if artificial intelligence or expert systems techniques are employed. 28 refs., figs

  20. Three-dimensional fluorescence lifetime tomography

    International Nuclear Information System (INIS)

    Godavarty, Anuradha; Sevick-Muraca, Eva M.; Eppstein, Margaret J.

    2005-01-01

    Near-infrared fluorescence tomography using molecularly targeted lifetime-sensitive, fluorescent contrast agents have applications for early-stage cancer diagnostics. Yet, although the measurement of fluorescent lifetime imaging microscopy (FLIM) is extensively used in microscopy and spectroscopy applications, demonstration of fluorescence lifetime tomography for medical imaging is limited to two-dimensional studies. Herein, the feasibility of three-dimensional fluorescence-lifetime tomography on clinically relevant phantom volumes is established, using (i) a gain-modulated intensified charge coupled device (CCD) and modulated laser diode imaging system, (ii) two fluorescent contrast agents, e.g., Indocyanine green and 3-3'-Diethylthiatricarbocyanine iodide differing in their fluorescence lifetime by 0.62 ns, and (iii) a two stage approximate extended Kalman filter reconstruction algorithm. Fluorescence measurements of phase and amplitude were acquired on the phantom surface under different target to background fluorescence absorption (70:1, 100:1) and fluorescence lifetime (1:1, 2.1:1) contrasts at target depths of 1.4-2 cm. The Bayesian tomography algorithm was employed to obtain three-dimensional images of lifetime and absorption owing to the fluorophores

  1. Three-dimensional image signals: processing methods

    Science.gov (United States)

    Schiopu, Paul; Manea, Adrian; Craciun, Anca-Ileana; Craciun, Alexandru

    2010-11-01

    Over the years extensive studies have been carried out to apply coherent optics methods in real-time processing, communications and transmission image. This is especially true when a large amount of information needs to be processed, e.g., in high-resolution imaging. The recent progress in data-processing networks and communication systems has considerably increased the capacity of information exchange. We describe the results of literature investigation research of processing methods for the signals of the three-dimensional images. All commercially available 3D technologies today are based on stereoscopic viewing. 3D technology was once the exclusive domain of skilled computer-graphics developers with high-end machines and software. The images capture from the advanced 3D digital camera can be displayed onto screen of the 3D digital viewer with/ without special glasses. For this is needed considerable processing power and memory to create and render the complex mix of colors, textures, and virtual lighting and perspective necessary to make figures appear three-dimensional. Also, using a standard digital camera and a technique called phase-shift interferometry we can capture "digital holograms." These are holograms that can be stored on computer and transmitted over conventional networks. We present some research methods to process "digital holograms" for the Internet transmission and results.

  2. Three dimensional animated images of anorectal malformations

    International Nuclear Information System (INIS)

    Ueno, Shigeru; Yanagimachi, Noriharu; Muro, Isao; Komiya, Taizo; Yokoyama, Seishichi; Hirakawa, Hitoshi; Tajima, Tomoo; Mitomi, Toshio; Suto, Yasuzo.

    1996-01-01

    Accurate reconstruction of the pelvic structures is a most important factor in obtaining a desirable result after anorectoplasty for a patient with anorectal malformation. Preoperative evaluation of the anatomy is indispensable for choosing an appropriate operative method in each case. To facilitate preoperative evaluation, three dimensional animated images of the pelvic structure of patients with anorectal malformations were constructed by computer graphics based upon tomographic images obtained from magnetic resonance imaging. Axial 1-mm thick images of the pelvic portion were generated with spoiling pulse gradient echo sequences using short repetition times (13 msec TR) and short echo times (6 msec TE) with a flip angle of 25 degrees with the patient in the jack-knife position. Graphic data from MR images were transferred to a graphic work station and processed on it. The skin surface, the ano-rectum, the lower urinary tract and the sphincter musculature were segmented by thresholding images by the signal intensity. Three dimensional images were displayed by surface rendering method using the segmented data of each organ and then animation images of these organs were obtained. The anatomy of each type of anomaly was easily recognized by 3-D visualization, and animation of the pelvic viscera and the sphincter musculature made the images more realistic. Animated images of the musculature were especially useful for simulating surgical procedures and could be helpful for reviewing surgical results. (author)

  3. Three-dimensional analysis of antenna sheaths

    International Nuclear Information System (INIS)

    Myra, J.R.; D'Ippolito, D.A.; Ho, Y.L.

    1996-01-01

    The present work is motivated by the importance of r.f. sheaths in determining the antenna-plasma interaction and the sensitivity of the sheaths to the complicated three-dimensional structure of modern ion cyclotron range of frequency (ICRF) antennas. To analyze r.f. sheaths on the plasma facing regions of the launcher, we first calculate the contact points of the tokamak magnetic field lines on the surface of the antenna Faraday screen and nearby limiters for realistic three-dimensional magnetic flux surface and antenna geometries. Next, the r.f. voltage that can drive sheaths at the contact points is determined and used to assess the resulting sheath power dissipation, r.f.-driven sputtering, and r.f.-induced convective cells (which produce edge profile modification). The calculations are embodied in a computer code, ANSAT (antenna sheath analysis tool), and sample ANSAT runs are shown to highlight the physics- and geometry-dependent characteristics of the r.f. sheaths and their relationship to the antenna design. One use of ANSAT is therefore as a design tool, to assess the strengths and weaknesses of a given design with respect to critical voltage handling and edge plasma interaction issues. Additionally, examples are presented where ANSAT has been useful in the analysis and interpretation of ICRF experiments (orig.)

  4. Three-dimensional visual feature representation in the primary visual cortex.

    Science.gov (United States)

    Tanaka, Shigeru; Moon, Chan-Hong; Fukuda, Mitsuhiro; Kim, Seong-Gi

    2011-12-01

    In the cat primary visual cortex, it is accepted that neurons optimally responding to similar stimulus orientations are clustered in a column extending from the superficial to deep layers. The cerebral cortex is, however, folded inside a skull, which makes gyri and fundi. The primary visual area of cats, area 17, is located on the fold of the cortex called the lateral gyrus. These facts raise the question of how to reconcile the tangential arrangement of the orientation columns with the curvature of the gyrus. In the present study, we show a possible configuration of feature representation in the visual cortex using a three-dimensional (3D) self-organization model. We took into account preferred orientation, preferred direction, ocular dominance and retinotopy, assuming isotropic interaction. We performed computer simulation only in the middle layer at the beginning and expanded the range of simulation gradually to other layers, which was found to be a unique method in the present model for obtaining orientation columns spanning all the layers in the flat cortex. Vertical columns of preferred orientations were found in the flat parts of the model cortex. On the other hand, in the curved parts, preferred orientations were represented in wedge-like columns rather than straight columns, and preferred directions were frequently reversed in the deeper layers. Singularities associated with orientation representation appeared as warped lines in the 3D model cortex. Direction reversal appeared on the sheets that were delimited by orientation-singularity lines. These structures emerged from the balance between periodic arrangements of preferred orientations and vertical alignment of the same orientations. Our theoretical predictions about orientation representation were confirmed by multi-slice, high-resolution functional MRI in the cat visual cortex. We obtained a close agreement between theoretical predictions and experimental observations. The present study throws a

  5. Three-dimensional simulations of the surface topography evolution of niobium superconducting radio frequency cavities

    Directory of Open Access Journals (Sweden)

    Rađenović Branislav M.

    2014-01-01

    Full Text Available This paper contains results of the three-dimensional simulations of the surface topography evolution of the niobium superconducting radio frequency cavities during isotropic and anisotropic etching modes. The initial rough surface is determined from the experimental power spectral density. The simulation results based on the level set method reveal that the time dependence of the root mean square roughness obeys Family-Viscek scaling law. The growth exponential factors b are determined for both etching modes. Exponential factor for the isotropic etching is 100 times lower than that for the anisotropic etching mode reviling that the isotropic etching is very useful mechanism of the smoothing. [Projekat Ministarstva nauke Republike Srbije, br. O171037 i br. III45006

  6. Steady, three-dimensional, internally heated convection

    International Nuclear Information System (INIS)

    Schubert, G.; Glatzmaier, G.A.; Travis, B.

    1993-01-01

    Numerical calculations have been carried out of steady, symmetric, three-dimensional modes of convection in internally heated, infinite Prandtl number, Boussinesq fluids at a Rayleigh number of 1.4x10 4 in a spherical shell with inner/outer radius of 0.55 and in a 3x3x1 rectangular box. Multiple patterns of convection occur in both geometries. In the Cartesian geometry the patterns are dominated by cylindrical cold downflows and a broad hot upwelling. In the spherical geometry the patterns consist of cylindrical cold downwellings centered either at the vertices of a tetrahedron or the centers of the faces of a cube. The cold downflow cylinders are immersed in a background of upwelling within which there are cylindrical hot concentrations (plumes) and hot halos around the downflows. The forced hot upflow return plumes of internally heated spherical convection are fundamentally different from the buoyancy-driven plumes of heated from below convection

  7. Exact solutions in three-dimensional gravity

    CERN Document Server

    Garcia-Diaz, Alberto A

    2017-01-01

    A self-contained text, systematically presenting the determination and classification of exact solutions in three-dimensional Einstein gravity. This book explores the theoretical framework and general physical and geometrical characteristics of each class of solutions, and includes information on the researchers responsible for their discovery. Beginning with the physical character of the solutions, these are identified and ordered on the basis of their geometrical invariant properties, symmetries, and algebraic classifications, or from the standpoint of their physical nature, for example electrodynamic fields, fluid, scalar field, or dilaton. Consequently, this text serves as a thorough catalogue on 2+1 exact solutions to the Einstein equations coupled to matter and fields, and on vacuum solutions of topologically massive gravity with a cosmological constant. The solutions are also examined from different perspectives, enabling a conceptual bridge between exact solutions of three- and four-dimensional gravit...

  8. Three-dimensional printing physiology laboratory technology.

    Science.gov (United States)

    Sulkin, Matthew S; Widder, Emily; Shao, Connie; Holzem, Katherine M; Gloschat, Christopher; Gutbrod, Sarah R; Efimov, Igor R

    2013-12-01

    Since its inception in 19th-century Germany, the physiology laboratory has been a complex and expensive research enterprise involving experts in various fields of science and engineering. Physiology research has been critically dependent on cutting-edge technological support of mechanical, electrical, optical, and more recently computer engineers. Evolution of modern experimental equipment is constrained by lack of direct communication between the physiological community and industry producing this equipment. Fortunately, recent advances in open source technologies, including three-dimensional printing, open source hardware and software, present an exciting opportunity to bring the design and development of research instrumentation to the end user, i.e., life scientists. Here we provide an overview on how to develop customized, cost-effective experimental equipment for physiology laboratories.

  9. Towards microscale electrohydrodynamic three-dimensional printing

    International Nuclear Information System (INIS)

    He, Jiankang; Xu, Fangyuan; Cao, Yi; Liu, Yaxiong; Li, Dichen

    2016-01-01

    It is challenging for the existing three-dimensional (3D) printing techniques to fabricate high-resolution 3D microstructures with low costs and high efficiency. In this work we present a solvent-based electrohydrodynamic 3D printing technique that allows fabrication of microscale structures like single walls, crossed walls, lattice and concentric circles. Process parameters were optimized to deposit tiny 3D patterns with a wall width smaller than 10 μm and a high aspect ratio of about 60. Tight bonding among neighbour layers could be achieved with a smooth lateral surface. In comparison with the existing microscale 3D printing techniques, the presented method is low-cost, highly efficient and applicable to multiple polymers. It is envisioned that this simple microscale 3D printing strategy might provide an alternative and innovative way for application in MEMS, biosensor and flexible electronics. (paper)

  10. Three-dimensional hologram display system

    Science.gov (United States)

    Mintz, Frederick (Inventor); Chao, Tien-Hsin (Inventor); Bryant, Nevin (Inventor); Tsou, Peter (Inventor)

    2009-01-01

    The present invention relates to a three-dimensional (3D) hologram display system. The 3D hologram display system includes a projector device for projecting an image upon a display medium to form a 3D hologram. The 3D hologram is formed such that a viewer can view the holographic image from multiple angles up to 360 degrees. Multiple display media are described, namely a spinning diffusive screen, a circular diffuser screen, and an aerogel. The spinning diffusive screen utilizes spatial light modulators to control the image such that the 3D image is displayed on the rotating screen in a time-multiplexing manner. The circular diffuser screen includes multiple, simultaneously-operated projectors to project the image onto the circular diffuser screen from a plurality of locations, thereby forming the 3D image. The aerogel can use the projection device described as applicable to either the spinning diffusive screen or the circular diffuser screen.

  11. Three-dimensional echocardiography in valve disease

    Directory of Open Access Journals (Sweden)

    Cesare Fiorentini

    2009-08-01

    Full Text Available This review covers the role of three-dimensional (3D echocardiography in the diagnosis of heart valve disease. Several factors have contributed to the evolution of this technique, which is currently a simple and routine method: rapid evolution in probe and computer technologies, demonstration that 3D data sets allowed more complete and accurate evaluation of cardiac structures, emerging clinical experience indicating the strong potential particularly in valve diseases, volume and function of the two ventricle measurements and several other fields. This report will review current and future applications of 3D echocardiography in mitral, aortic and tricuspid valve diseases underlying both qualitative (morphologic and quantitative advantages of this technique. (Heart International 2007; 3: 35-41

  12. Towards microscale electrohydrodynamic three-dimensional printing

    Science.gov (United States)

    He, Jiankang; Xu, Fangyuan; Cao, Yi; Liu, Yaxiong; Li, Dichen

    2016-02-01

    It is challenging for the existing three-dimensional (3D) printing techniques to fabricate high-resolution 3D microstructures with low costs and high efficiency. In this work we present a solvent-based electrohydrodynamic 3D printing technique that allows fabrication of microscale structures like single walls, crossed walls, lattice and concentric circles. Process parameters were optimized to deposit tiny 3D patterns with a wall width smaller than 10 μm and a high aspect ratio of about 60. Tight bonding among neighbour layers could be achieved with a smooth lateral surface. In comparison with the existing microscale 3D printing techniques, the presented method is low-cost, highly efficient and applicable to multiple polymers. It is envisioned that this simple microscale 3D printing strategy might provide an alternative and innovative way for application in MEMS, biosensor and flexible electronics.

  13. An Introduction of Three-dimensional Grammar

    Directory of Open Access Journals (Sweden)

    Fan Xiao

    2017-12-01

    Full Text Available This paper introduces some key points of Three-dimensional Grammar. As for the structure, it can be distinguished into syntactic structure, semantic structure and pragmatic structure from the perspectives of syntax, semantics and pragmatics. And the same is true with the followings, such as grammatical constituents, grammatical functions, grammatical meanings, grammatical focuses. Sentence types which is called sentence pattern, sentence model and sentence types respectively, and analysis methods. This paper proposes that grammatical researches should be done in accordance with the four principles, that is form and meaning co-verified, static and dynamic co-referenced, structure and function co-testified and description and interpretation co-promoted.

  14. Three-dimensional function photonic crystals

    Science.gov (United States)

    Zhang, Hai-Feng

    2017-11-01

    In this paper, the properties of the photonic band gaps (PBGs) of three-dimensional (3D) function photonic crystals (PCs) are theoretically investigated by a modified plane wave expansion (PWE) method, whose equations for computations are deduced. The configuration of 3D function PCs is the dielectric spheres inserted in the air background with simple-cubic (SC) lattices whose dielectric constants are the functions of space coordinates, which can be realized by the electro-optical or optical Kerr effect in the practice. The influences of the parameter for 3D function PCs on the PBGs also are discussed. The calculated results show that the bandwidths and number of PBGs can be tuned with different distributions of function dielectrics. Compared with the conventional 3D dielectric PCs with SC lattices, the larger and more PBGs can be obtained in the 3D function PCs. Those results provide a new way to design the novel practical devices.

  15. Three-dimensional tori and Arnold tongues

    Energy Technology Data Exchange (ETDEWEB)

    Sekikawa, Munehisa, E-mail: sekikawa@cc.utsunomiya-u.ac.jp [Department of Mechanical and Intelligent Engineering, Utsunomiya University, Utsunomiya-shi 321-8585 (Japan); Inaba, Naohiko [Organization for the Strategic Coordination of Research and Intellectual Property, Meiji University, Kawasaki-shi 214-8571 (Japan); Kamiyama, Kyohei [Department of Electronics and Bioinformatics, Meiji University, Kawasaki-shi 214-8571 (Japan); Aihara, Kazuyuki [Institute of Industrial Science, the University of Tokyo, Meguro-ku 153-8505 (Japan)

    2014-03-15

    This study analyzes an Arnold resonance web, which includes complicated quasi-periodic bifurcations, by conducting a Lyapunov analysis for a coupled delayed logistic map. The map can exhibit a two-dimensional invariant torus (IT), which corresponds to a three-dimensional torus in vector fields. Numerous one-dimensional invariant closed curves (ICCs), which correspond to two-dimensional tori in vector fields, exist in a very complicated but reasonable manner inside an IT-generating region. Periodic solutions emerge at the intersections of two different thin ICC-generating regions, which we call ICC-Arnold tongues, because all three independent-frequency components of the IT become rational at the intersections. Additionally, we observe a significant bifurcation structure where conventional Arnold tongues transit to ICC-Arnold tongues through a Neimark-Sacker bifurcation in the neighborhood of a quasi-periodic Hopf bifurcation (or a quasi-periodic Neimark-Sacker bifurcation) boundary.

  16. Multiscale modeling of three-dimensional genome

    Science.gov (United States)

    Zhang, Bin; Wolynes, Peter

    The genome, the blueprint of life, contains nearly all the information needed to build and maintain an entire organism. A comprehensive understanding of the genome is of paramount interest to human health and will advance progress in many areas, including life sciences, medicine, and biotechnology. The overarching goal of my research is to understand the structure-dynamics-function relationships of the human genome. In this talk, I will be presenting our efforts in moving towards that goal, with a particular emphasis on studying the three-dimensional organization, the structure of the genome with multi-scale approaches. Specifically, I will discuss the reconstruction of genome structures at both interphase and metaphase by making use of data from chromosome conformation capture experiments. Computationally modeling of chromatin fiber at atomistic level from first principles will also be presented as our effort for studying the genome structure from bottom up.

  17. Three-dimensional reconstruction of CT images

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Toshiaki; Kattoh, Keiichi; Kawakami, Genichiroh; Igami, Isao; Mariya, Yasushi; Nakamura, Yasuhiko; Saitoh, Yohko; Tamura, Koreroku; Shinozaki, Tatsuyo

    1986-09-01

    Computed tomography (CT) has the ability to provide sensitive visualization of organs and lesions. Owing to the nature of CT to be transaxial images, a structure which is greater than a certain size appears as several serial CT images. Consequently each observer must reconstruct those images into a three-dimensional (3-D) form mentally. It has been supposed to be of great use if such a 3-D form can be described as a definite figure. A new computer program has been developed which can produce 3-D figures from the profiles of organs and lesions on CT images using spline curves. The figures obtained through this method are regarded to have practical applications.

  18. The Three-Dimensional EIT Wave

    Science.gov (United States)

    Thompson, B. J.; Biesecker, D. A.; Gilbert, H. R.; Lawrence, G. R.; Ofman, L.; Wu, S. T.; Warmuth, A.; Fisher, Richard R. (Technical Monitor)

    2002-01-01

    An EIT wave is an impulsive disturbance which has been observed in the EUV, Soft X-ray and white light corona, with corresponding observations in the chromosphere. The effects of these disturbances can be observed across the entire solar disk of the Sun, and throughout the inner heliosphere as well. However, the picture is not complete; observations alone do not establish a complete understanding of the nature of this three-dimensional phenomenon. A number of associated phenomena have been documented, though in most cases causality has not determined. Additionally, it is unclear which factors govern the impulse's ability to affect regions of the corona and heliosphere. We discuss the various observations and the models which provided links between the associated phenomena.

  19. Three-dimensional model for fusion processes

    International Nuclear Information System (INIS)

    Olson, A.P.

    1984-01-01

    Active galactic nuclei (AGN) emit unusual spectra of radiation which is interpreted to signify extreme distance, extreme power, or both. The status of AGNs was recently reviewed by Balick and Heckman. It seems that the greatest conceptual difficulty with understanding AGNs is how to form a coherent phenomenological model of their properties. What drives the galactic engine. What and where are the mass-flows of fuel to this engine. Are there more than one engine. Do the engines have any symmetry properties. Is observed radiation isotropically emitted from the source. If it is polarized, what causes the polarization. Why is there a roughly spherical cloud of ionized gas about the center of our own galaxy, the Milky Way. The purpose of this paper is to discuss a new model, based on fusion processes which are not axisymmetric, uniform, isotropic, or even time-invariant. Then, the relationship to these questions will be developed. A unified model of fusion processes applicable to many astronomical phenomena will be proposed and discussed

  20. Three-dimensional (3D) analysis of the temporomandibular joint

    DEFF Research Database (Denmark)

    Kitai, N.; Kreiborg, S.; Murakami, S.

    Symposium Orthodontics 2001: Where are We Now? Where are We Going?, three-dimensional analysis, temporomandibular joint......Symposium Orthodontics 2001: Where are We Now? Where are We Going?, three-dimensional analysis, temporomandibular joint...

  1. Three-dimensional display of magnetic source imaging (MSI)

    International Nuclear Information System (INIS)

    Morioka, Takato; Yamamoto, Tomoya; Nishio, Shunji; Hasuo, Kanehiro; Fujii, Kiyotaka; Fukui, Masashi; Nitta, Koichi.

    1995-01-01

    Magnetic source imaging (MSI) is a relatively new, noninvasive technique for defining the relationship between brain structure and function of individual patients, and to establish comparisons from one patient to another. This is achieved by combining detailed neurophysiological data derived via magnetoencephalography (MEG) with neuroimaging data such as computed tomographic scan and magnetic resonance imaging (MRI). The noninvasive presurgical mapping of cortical functional somatosensory activity and the direct mapping of epilepsy-associated activity are among the neurosurgical uses that are emerging for MSI. Although the procedure provides clinically useful data, there are still limitations to two-dimensional MSI. We employ three-dimensional (3-D) MSI, superimposing MSI localizations on 3-D volumetric reconstruction of MRI. 3-D MSI enhances the visualization of the entire sensory homunculus and clearly demonstrates the spatial relationship with structural lesions. The functional localization of the epileptic focus in spatial relation to the lesion provides important clues for preoperative planning and on the epileptogenicity of the lesion. 3-D MSI improves localization of the sensory cortex and generator areas of epileptic activity. (author)

  2. Three-dimensional magnetic resonance imaging for ruptures of the lateral ligaments of the ankle

    International Nuclear Information System (INIS)

    Verhaven, E.; Handelberg, F.; Opdecam, P.; Shahabpour, M.; Osteaux, M.; Vaes, P.

    1990-01-01

    The accuracy has been determined of three-dimensional MRI in visualizing the anterior talofibular and the calcaneofibular ligament in young athletes with an acute severe sprain of the lateral ligaments of the ankle by comparing these findings with those found at operation and evaluating three-dimensional fast imaging with steady state precession (3D FISP) as a diagnostic aid to operative planning for tears of both the anterior talofibular and the calcaneofibular ligament in younger competitive athletes. (author). 20 refs.; 2 figs

  3. Study on three dimensional seismic isolation system

    International Nuclear Information System (INIS)

    Morishita, Masaki; Kitamura, Seiji

    2003-01-01

    Japan Nuclear Cycle Development Institute (JNC) and Japan Atomic Power Company (JAPC) launched joint research programs on structural design and three-dimensional seismic isolation technologies, as part of the supporting R and D activities for the feasibility studies on commercialized fast breeder reactor cycle systems. A research project by JAPC under the auspices of the Ministry of Economy, Trade, and Industry (METI) with technical support by JNC is included in this joint study. This report contains the results of the research on the three-dimensional seismic isolation technologies, and the results of this year's study are summarized in the following five aspects. (1) Study on Earthquake Condition for Developing 3-dimensional Base Isolation System. The case study S2 is one of the maximum ground motions, of which the records were investigated up to this time. But a few observed near the fault exceed the case study S2 in the long period domain, depending on the fault length and conditions. Generally it is appropriate that the response spectra ratio (vertical/horizontal) is 0.6. (2) Performance Requirement for 3-dimensional Base Isolation System and Devices. Although the integrity map of main equipment/piping dominate the design criteria for the 3-dimensional base isolation system, the combined integrity map is the same as those of FY 2000, which are under fv=1Hz and over hv=20%. (3) Developing Targets and Schedule for 3-dimensional Isolation Technology. The target items for 3-dimensional base isolation system were rearranged into a table, and developing items to be examined concerning the device were also adjusted. A development plan until FY 2009 was made from the viewpoint of realization and establishment of a design guideline on 3-dimensional base isolation system. (4) Study on 3-dimensional Entire Building Base Isolation System. Three ideas among six ideas that had been proposed in FY2001, i.e., '3-dimensional base isolation system incorporating hydraulic

  4. Scale-invariance in three-dimensional isotropic turbulence: a paradox and its resolution

    International Nuclear Information System (INIS)

    McComb, David

    2008-01-01

    If the Reynolds number is large enough, turbulence is expected to exhibit scale invariance in an intermediate ('inertial') range of wave numbers, as shown by power-law behaviour of the energy spectrum and also by a constant rate of energy transfer through wave number. However, although it has long been known that the first of these is true, there has been little recognition of the fact that, if the second is to hold, then there is a contradiction between the definition of the energy flux (as the integral of the transfer spectrum) and the observed behaviour of the transfer spectrum itself. This is because the transfer spectrum T(k) is invariably found to have a zero crossing at a single point (at k 0 , say), implying that the corresponding energy flux cannot have an extended plateau but must instead have a maximum value at k = k 0 . We outline the resulting paradox and note that it may be resolved by the observation that the symmetry of the triadic interactions means that T(k) is not the relevant transfer term in determining the energy flux. Instead the relevant term is a filtered/partitioned version, herein denoted by T +- (k|k c ), where k = k c is the cut-off wave number for low/high-pass filtering. It is known from studies of spectral subgrid transfer that T +- (k|k c ) is zero over an extended range of wave numbers. As this is the case for quite modest Reynolds numbers, it not only resolves the paradox, but may also shed some light on the 'embarrassment of success' of the Kolmogorov theory

  5. Bifurcation analysis of a three dimensional system

    Directory of Open Access Journals (Sweden)

    Yongwen WANG

    2018-04-01

    Full Text Available In order to enrich the stability and bifurcation theory of the three dimensional chaotic systems, taking a quadratic truncate unfolding system with the triple singularity equilibrium as the research subject, the existence of the equilibrium, the stability and the bifurcation of the system near the equilibrium under different parametric conditions are studied. Using the method of mathematical analysis, the existence of the real roots of the corresponding characteristic equation under the different parametric conditions is analyzed, and the local manifolds of the equilibrium are gotten, then the possible bifurcations are guessed. The parametric conditions under which the equilibrium is saddle-focus are analyzed carefully by the Cardan formula. Moreover, the conditions of codimension-one Hopf bifucation and the prerequisites of the supercritical and subcritical Hopf bifurcation are found by computation. The results show that the system has abundant stability and bifurcation, and can also supply theorical support for the proof of the existence of the homoclinic or heteroclinic loop connecting saddle-focus and the Silnikov's chaos. This method can be extended to study the other higher nonlinear systems.

  6. Three-dimensional dynamics of protostellar evolution

    International Nuclear Information System (INIS)

    Cook, T.L.

    1977-06-01

    A three-dimensional finite difference numerical methodology was developed for self-gravitating, rotating gaseous systems. The fully nonlinear equations for time-varying fluid dynamics are solved by high speed computer in a cylindrical coordinate system rotating with an instantaneous angular velocity, selected such that the net angular momentum relative to the rotating frame is zero. The time-dependent adiabatic collapse of gravitationally bound, rotating, protostellar clouds is studied for specified uniform and nonuniform initial conditions. Uniform clouds can form axisymmetric, rotating toroidal configurations. If the thermal pressure is high, nonuniform clouds can also collapse to axisymmetric toroids. For low thermal pressures, however, the collapsing cloud is unstable to initial perturbations. The fragmentation of protostellar clouds is investigated by studying the response of rotating, self-gravitating, equilibrium toroids to non-axisymmetric perturbations. The detailed evolution of the fragmenting toroid depends upon a non-dimensional function of the initial entropy, the total mass in the toroid, the angular velocity of rotation, and the number of perturbation wavelengths around the circumference of the toroid. For low and intermediate entropies, the configuration develops into co-rotating components with spiral streamers. In the spiral regions retrograde vortices are observed in some examples. For high levels of entropy, barred spirals can exist as intermediate states of the fragmentation

  7. Three-dimensional dynamics of protostellar evolution

    International Nuclear Information System (INIS)

    Cook, T.L.; Harlow, F.H.

    1978-01-01

    A three-dimensional finite difference numerical methodology has been developed for self-gravitating, rotating gaseous systems. The fully nonlinear equations for time-varying fluid dynamics are solved by high-speed computer in a cylindrical coordinate system rotating with an instantaneous angular velocity. The time-dependent adiabatic collapse of gravitationally bound, rotating, protostellar clouds is studied for specified uniform and nonuniform initial conditions. Uniform clouds can form axisymmetric, rotating toroidal configurations. If the thermal pressure is high, nonuniform clouds can also collapse to axisymmetric ellipsoids. For low thermal pressures, however, the collapsing cloud is unstable to perturbations. The resulting fragmentation of unstable protostellar clouds is investigated by studying the response of rotating, self-gravitating, equilibrium toroids to nonaxisymmetric perturbations. The detailed evolution of the fragmentation toroid depends upon a nondimensional function of the initial entropy, the total mass in the toroid, the angular velocity of rotation, and the number of perturbation wave-lengths around the circumference of the toroid. For low and intermediate entropies, the configuration develops into corotating components with spiral streamers. In the spiral regions retrograde vortices are observed in some examples. For high levels of entropy, barred spirals can exist as intermediate states of the fragmentation

  8. Three dimensional characterization and archiving system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1995-01-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D ampersand D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D ampersand D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. Chemical analysis plays a vital role throughout the process of decontamination. Before clean-up operations can begin the site must be characterized with respect to the type and concentration of contaminants, and detailed site mapping must clarify areas of both high and low risk. During remediation activities chemical analysis provides a means to measure progress and to adjust clean-up strategy. Once the clean-up process has been completed the results of chemical analysis will verify that the site is in compliance with federal and local regulations

  9. MORPHOLOGICAL DESCRIPTIONS USING THREE-DIMENSIONAL WAVEFRONTS

    Directory of Open Access Journals (Sweden)

    Jean Serra

    2011-05-01

    Full Text Available The present study deals with the analysis of three-dimensional binary objects whose structure is not obvious nor generally clearly visible. Our approach is illustrated through three examples taken from biological microscopy. In one of our examples, we need to extract the osteocytes contained in sixty confocal sections. The cells are not numerous, but are characterized by long branches, hence they will be separated using a directional wavefront The two other objects are more complex and will be analysed by means of a spherical wavefront In the first case, a kidney of a rat embryo, the tissue grows like a tree, where we want to detect the branches, their extremities,and their spatial arrangement. The wavefront method enables us to define precisely branches and extremities, and gives flexible algorithms. The last example deals with the embryonic growth of the chicken shinbone. The central part of the bone (or shaft is structured as a series of nested cylinders following the same axis, and connected by more or less long bridges. Using wavefronts, we show that it is possible to separate the cylinders,and to extract and count the bridges that connect them.

  10. Multimodal three-dimensional dynamic signature

    Directory of Open Access Journals (Sweden)

    Yury E. Kozlov

    2017-11-01

    Full Text Available Reliable authentication in mobile applications is among the most important information security challenges. Today, we can hardly imagine a person who would not own a mobile device that connects to the Internet. Mobile devices are being used to store large amounts of confidential information, ranging from personal photos to electronic banking tools. In 2009, colleagues from Rice University together with their collaborators from Motorola, proposed an authentication through in-air gestures. This and subsequent work contributing to the development of the method are reviewed in our introduction. At the moment, there exists a version of the gesture-based authentication software available for Android mobile devices. This software has not become widespread yet. One of likely reasons for that is the insufficient reliability of the method, which involves similar to its earlier analogs the use of only one device. Here we discuss the authentication based on the multimodal three-dimensional dynamic signature (MTDS performed by two independent mobile devices. The MTDS-based authentication technique is an advanced version of in-air gesture authentication. We describe the operation of a prototype of MTDS-based authentication, including the main implemented algorithms, as well as some preliminary results of testing the software. We expect that our method can be used in any mobile application, provided a number of additional improvements discussed in the conclusion are made.

  11. Three-Dimensional Printed Thermal Regulation Textiles.

    Science.gov (United States)

    Gao, Tingting; Yang, Zhi; Chen, Chaoji; Li, Yiju; Fu, Kun; Dai, Jiaqi; Hitz, Emily M; Xie, Hua; Liu, Boyang; Song, Jianwei; Yang, Bao; Hu, Liangbing

    2017-11-28

    Space cooling is a predominant part of energy consumption in people's daily life. Although cooling the whole building is an effective way to provide personal comfort in hot weather, it is energy-consuming and high-cost. Personal cooling technology, being able to provide personal thermal comfort by directing local heat to the thermally regulated environment, has been regarded as one of the most promising technologies for cooling energy and cost savings. Here, we demonstrate a personal thermal regulated textile using thermally conductive and highly aligned boron nitride (BN)/poly(vinyl alcohol) (PVA) composite (denoted as a-BN/PVA) fibers to improve the thermal transport properties of textiles for personal cooling. The a-BN/PVA composite fibers are fabricated through a fast and scalable three-dimensional (3D) printing method. Uniform dispersion and high alignment of BN nanosheets (BNNSs) can be achieved during the processing of fiber fabrication, leading to a combination of high mechanical strength (355 MPa) and favorable heat dispersion. Due to the improved thermal transport property imparted by the thermally conductive and highly aligned BNNSs, better cooling effect (55% improvement over the commercial cotton fiber) can be realized in the a-BN/PVA textile. The wearable a-BN/PVA textiles containing the 3D-printed a-BN/PVA fibers offer a promising selection for meeting the personal cooling requirement, which can significantly reduce the energy consumption and cost for cooling the whole building.

  12. Three-dimensional printing for craniomaxillofacial regeneration.

    Science.gov (United States)

    Gaviria, Laura; Pearson, Joseph J; Montelongo, Sergio A; Guda, Teja; Ong, Joo L

    2017-10-01

    Craniomaxillofacial injuries produce complex wound environments involving various tissue types and treatment strategies. In a clinical setting, care is taken to properly irrigate and stabilize the injury, while grafts are molded in an attempt to maintain physiological functionality and cosmesis. This often requires multiple surgeries and grafts leading to added discomfort, pain and financial burden. Many of these injuries can lead to disfigurement and resultant loss of system function including mastication, respiration, and articulation, and these can lead to acute and long-term psychological impact on the patient. A main causality of these issues is the lack of an ability to spatially control pre-injury morphology while maintaining shape and function. With the advent of additive manufacturing (three-dimensional printing) and its use in conjunction with biomaterial regenerative strategies and stem cell research, there is an increased potential capacity to alleviate such limitations. This review focuses on the current capabilities of additive manufacturing platforms, completed research and potential for future uses in the treatment of craniomaxillofacial injuries, with an in-depth discussion of regeneration of the periodontal complex and teeth.

  13. Three-dimensional supersonic vortex breakdown

    Science.gov (United States)

    Kandil, Osama A.; Kandil, Hamdy A.; Liu, C. H.

    1993-01-01

    Three-dimensional supersonic vortex-breakdown problems in bound and unbound domains are solved. The solutions are obtained using the time-accurate integration of the unsteady, compressible, full Navier-Stokes (NS) equations. The computational scheme is an implicit, upwind, flux-difference splitting, finite-volume scheme. Two vortex-breakdown applications are considered in the present paper. The first is for a supersonic swirling jet which is issued from a nozzle into a supersonic uniform flow at a lower Mach number than that of the swirling jet. The second is for a supersonic swirling flow in a configured circular duct. In the first application, an extensive study of the effects of grid fineness, shape and grid-point distribution on the vortex breakdown is presented. Four grids are used in this study and they show a substantial dependence of the breakdown bubble and shock wave on the grid used. In the second application, the bubble-type and helix-type vortex breakdown have been captured.

  14. Three-dimensional laparoscopy: Principles and practice

    Directory of Open Access Journals (Sweden)

    Rakesh Y Sinha

    2017-01-01

    Full Text Available The largest challenge for laparoscopic surgeons is the eye–hand coordination within a three-dimensional (3D scene observed on a 2D display. The 2D view on flat screen laparoscopy is cerebrally intensive. The loss of binocular vision on a 2D display causes visual misperceptions, mainly loss of depth perception and adds to the surgeon's fatigue. This compromises the safety of laparoscopy. The 3D high-definition view with great depth perception and tactile feedback makes laparoscopic surgery more acceptable, safe and cost-effective. It improves surgical precision and hand–eye coordination, conventional and all straight stick instruments can be used, capital expenditure is less and recurring cost and annual maintenance cost are less. In this article, we have discussed the physics of 3D laparoscopy, principles of depth perception, and the different kinds of 3D systems available for laparoscopy. We have also discussed our experience of using 3D laparoscopy in over 2000 surgeries in the last 4 years.

  15. Three dimensional characterization and archiving system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastian, R.L.; Clark, R.; Gallman, P. [Coleman Research Corp., Springfield, VA (United States)] [and others

    1995-10-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D&D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D&D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. The 3D-ICAS system robotically conveys a multisensor probe near the surface to be inspected. The sensor position and orientation are monitored and controlled by Coherent laser radar (CLR) tracking. The ICAS fills the need for high speed automated organic analysis by means of gas chromatography-mass spectrometry sensors, and also by radionuclide sensors which combines alpha, beta, and gamma counting.

  16. Three dimensional characterization and archiving system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.; Gallman, P.

    1996-01-01

    The Three Dimensional Characterization and Archiving System (3D-ICAS) is being developed as a remote system to perform rapid in situ analysis of hazardous organics and radionuclide contamination on structural materials. Coleman Research and its subcontractors, Thermedics Detection, Inc. (TD) and the University of Idaho (UI) are in the second phase of a three phase program to develop 3D-ICAS to support Decontamination and Decommissioning (D and D) operations. Accurate physical characterization of surfaces and the radioactive and organic is a critical D and D task. Surface characterization includes identification of potentially dangerous inorganic materials, such as asbestos and transite. Real-time remotely operable characterization instrumentation will significantly advance the analysis capabilities beyond those currently employed. Chemical analysis is a primary area where the characterization process will be improved. The 3D-ICAS system robotically conveys a multisensor probe near the surfaces to be inspected. The sensor position and orientation are monitored and controlled using coherent laser radar (CLR) tracking. The CLR also provides 3D facility maps which establish a 3D world view within which the robotic sensor system can operate

  17. Three-dimensional RAMA fluence methodology benchmarking

    International Nuclear Information System (INIS)

    Baker, S. P.; Carter, R. G.; Watkins, K. E.; Jones, D. B.

    2004-01-01

    This paper describes the benchmarking of the RAMA Fluence Methodology software, that has been performed in accordance with U. S. Nuclear Regulatory Commission Regulatory Guide 1.190. The RAMA Fluence Methodology has been developed by TransWare Enterprises Inc. through funding provided by the Electric Power Research Inst., Inc. (EPRI) and the Boiling Water Reactor Vessel and Internals Project (BWRVIP). The purpose of the software is to provide an accurate method for calculating neutron fluence in BWR pressure vessels and internal components. The Methodology incorporates a three-dimensional deterministic transport solution with flexible arbitrary geometry representation of reactor system components, previously available only with Monte Carlo solution techniques. Benchmarking was performed on measurements obtained from three standard benchmark problems which include the Pool Criticality Assembly (PCA), VENUS-3, and H. B. Robinson Unit 2 benchmarks, and on flux wire measurements obtained from two BWR nuclear plants. The calculated to measured (C/M) ratios range from 0.93 to 1.04 demonstrating the accuracy of the RAMA Fluence Methodology in predicting neutron flux, fluence, and dosimetry activation. (authors)

  18. Three-Dimensional Printed Graphene Foams.

    Science.gov (United States)

    Sha, Junwei; Li, Yilun; Villegas Salvatierra, Rodrigo; Wang, Tuo; Dong, Pei; Ji, Yongsung; Lee, Seoung-Ki; Zhang, Chenhao; Zhang, Jibo; Smith, Robert H; Ajayan, Pulickel M; Lou, Jun; Zhao, Naiqin; Tour, James M

    2017-07-25

    An automated metal powder three-dimensional (3D) printing method for in situ synthesis of free-standing 3D graphene foams (GFs) was successfully modeled by manually placing a mixture of Ni and sucrose onto a platform and then using a commercial CO 2 laser to convert the Ni/sucrose mixture into 3D GFs. The sucrose acted as the solid carbon source for graphene, and the sintered Ni metal acted as the catalyst and template for graphene growth. This simple and efficient method combines powder metallurgy templating with 3D printing techniques and enables direct in situ 3D printing of GFs with no high-temperature furnace or lengthy growth process required. The 3D printed GFs show high-porosity (∼99.3%), low-density (∼0.015g cm -3 ), high-quality, and multilayered graphene features. The GFs have an electrical conductivity of ∼8.7 S cm -1 , a remarkable storage modulus of ∼11 kPa, and a high damping capacity of ∼0.06. These excellent physical properties of 3D printed GFs indicate potential applications in fields requiring rapid design and manufacturing of 3D carbon materials, for example, energy storage devices, damping materials, and sound absorption.

  19. Brain volume measurement using three-dimensional magnetic resonance images

    International Nuclear Information System (INIS)

    Ishimaru, Yoshihiro

    1996-01-01

    This study was designed to validate accurate measurement method of human brain volume using three dimensional (3D) MRI data on a workstation, and to establish optimal correcting method of human brain volume on diagnosis of brain atrophy. 3D MRI data were acquired by fast SPGR sequence using 1.5 T MR imager. 3D MRI data were segmented by region growing method and 3D image was displayed by surface rendering method on the workstation. Brain volume was measured by the volume measurement function of the workstation. In order to validate the accurate measurement method, phantoms and a specimen of human brain were examined. Phantom volume was measured by changing the lower level of threshold value. At the appropriate threshold value, percentage of error of phantoms and the specimen were within 0.6% and 0.08%, respectively. To establish the optimal correcting method, 130 normal volunteers were examined. Brain volumes corrected with height weight, body surface area, and alternative skull volume were evaluated. Brain volume index, which is defined as dividing brain volume by alternative skull volume, had the best correlation with age (r=0.624, p<0.05). No gender differences was observed in brain volume index in contrast to in brain volume. The clinical usefulness of this correcting method for brain atrophy diagnosis was evaluated in 85 patients. Diagnosis by 2D spin echo MR images was compared with brain volume index. Diagnosis of brain atrophy by 2D MR image was concordant with the evaluation by brain volume index. These results indicated that this measurement method had high accuracy, and it was important to set the appropriate threshold value. Brain volume index was the appropriate indication for evaluation of human brain volume, and was considered to be useful for the diagnosis of brain atrophy. (author)

  20. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyun Don; Park, Chang Seo [Dept. of Dental Radiology, College of Dentistry, Yensei University, Seoul (Korea, Republic of); Yoo, Sun Kook; Lee, Kyoung Sang [Dept. of Medical Engineering, College of Medicine, Yensei University, Seoul (Korea, Republic of)

    1998-08-15

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  1. Application of Simulated Three Dimensional CT Image in Orthognathic Surgery

    International Nuclear Information System (INIS)

    Kim, Hyun Don; Park, Chang Seo; Yoo, Sun Kook; Lee, Kyoung Sang

    1998-01-01

    In orthodontics and orthognathic surgery, cephalogram has been routine practice in diagnosis and treatment evaluation of craniofacial deformity. But its inherent distortion of actual length and angles during projecting three dimensional object to two dimensional plane might cause errors in quantitative analysis of shape and size. Therefore, it is desirable that three dimensional object is diagnosed and evaluated three dimensionally and three dimensional CT image is best for three dimensional analysis. Development of clinic necessitates evaluation of result of treatment and comparison before and after surgery. It is desirable that patient that was diagnosed and planned by three dimensional computed tomography before surgery is evaluated by three dimensional computed tomography after surgery, too. But Because there is no standardized normal values in three dimension now and three dimensional Computed Tomography needs expensive equipment and because of its expenses and amount of exposure to radiation, limitations still remain to be solved in its application to routine practice. If postoperative three dimensional image is constructed by pre and postoperative lateral and postero-anterior cephalograms and preoperative three dimensional computed tomogram, pre and postoperative image will be compared and evaluated three dimensionally without three dimensional computed tomography after surgery and that will contribute to standardize normal values in three dimension. This study introduced new method that computer-simulated three dimensional image was constructed by preoperative three dimensional computed tomogram and pre and postoperative lateral and postero-anterior cephalograms, and for validation of new method, in four cases of dry skull that position of mandible was displaced and four patients of orthognathic surgery, computer-simulated three dimensional image and actual postoperative three dimensional image were compared. The results were as follows. 1. In four cases of

  2. Panoramic three-dimensional CT imaging

    International Nuclear Information System (INIS)

    Kawamata, Akitoshi; Fujishita, Masami

    1998-01-01

    Panoramic radiography is a unique projection technique for producing a single image of both maxillary and mandibular arches and many other anatomical structures. To obtain a similar panoramic image without panoramic radiography system, a modified three-dimensional (3D) CT imaging technique was designed. A set of CT slice image data extending from the chin to the orbit was used for 3D reconstruction. The CT machine used in this study was the X-Vision (TOSHIBA, Japan). The helical scan technique was used. The slice thickness of reconstructed image was one or 1.5 mm. The occlusal plane or Frankfort horizontal (FH) plane was used as the reference line. The resultant slice image data was stored on a magnetic optical disk and then used to create panoramic 3D-CT images on a Macintosh computer systems (Power Macintosh 8600/250, Apple Computer Inc., USA). To create the panoramic 3D-CT image, the following procedure was designed: Design a curved panoramic 3D-CT imaging layer using the imaging layer and the movement of the x-ray beam in panoramic radiography system as a template; Cut this imaging layer from each slice image, then the trimmed image was transformed to a rectangular layer using the ''still image warping'' special effect in the Elastic Reality special effects system (Elastic Reality Inc., USA); Create panoramic 3D-CT image using the Voxel View (Vital Images Inc., USA) rendering system and volume rendering technique. Although the image quality was primitive, a panoramic view of maxillofacial region was obtained by this technique. (author)

  3. An analytic, approximate method for modeling steady, three-dimensional flow to partially penetrating wells

    Science.gov (United States)

    Bakker, Mark

    2001-05-01

    An analytic, approximate solution is derived for the modeling of three-dimensional flow to partially penetrating wells. The solution is written in terms of a correction on the solution for a fully penetrating well and is obtained by dividing the aquifer up, locally, in a number of aquifer layers. The resulting system of differential equations is solved by application of the theory for multiaquifer flow. The presented approach has three major benefits. First, the solution may be applied to any groundwater model that can simulate flow to a fully penetrating well; the solution may be superimposed onto the solution for the fully penetrating well to simulate the local three-dimensional drawdown and flow field. Second, the approach is applicable to isotropic, anisotropic, and stratified aquifers and to both confined and unconfined flow. Third, the solution extends over a small area around the well only; outside this area the three-dimensional effect of the partially penetrating well is negligible, and no correction to the fully penetrating well is needed. A number of comparisons are made to existing three-dimensional, analytic solutions, including radial confined and unconfined flow and a well in a uniform flow field. It is shown that a subdivision in three layers is accurate for many practical cases; very accurate solutions are obtained with more layers.

  4. Three-Dimensional Liver Surgery Simulation: Computer-Assisted Surgical Planning with Three-Dimensional Simulation Software and Three-Dimensional Printing.

    Science.gov (United States)

    Oshiro, Yukio; Ohkohchi, Nobuhiro

    2017-06-01

    To perform accurate hepatectomy without injury, it is necessary to understand the anatomical relationship among the branches of Glisson's sheath, hepatic veins, and tumor. In Japan, three-dimensional (3D) preoperative simulation for liver surgery is becoming increasingly common, and liver 3D modeling and 3D hepatectomy simulation by 3D analysis software for liver surgery have been covered by universal healthcare insurance since 2012. Herein, we review the history of virtual hepatectomy using computer-assisted surgery (CAS) and our research to date, and we discuss the future prospects of CAS. We have used the SYNAPSE VINCENT medical imaging system (Fujifilm Medical, Tokyo, Japan) for 3D visualization and virtual resection of the liver since 2010. We developed a novel fusion imaging technique combining 3D computed tomography (CT) with magnetic resonance imaging (MRI). The fusion image enables us to easily visualize anatomic relationships among the hepatic arteries, portal veins, bile duct, and tumor in the hepatic hilum. In 2013, we developed an original software, called Liversim, which enables real-time deformation of the liver using physical simulation, and a randomized control trial has recently been conducted to evaluate the use of Liversim and SYNAPSE VINCENT for preoperative simulation and planning. Furthermore, we developed a novel hollow 3D-printed liver model whose surface is covered with frames. This model is useful for safe liver resection, has better visibility, and the production cost is reduced to one-third of a previous model. Preoperative simulation and navigation with CAS in liver resection are expected to help planning and conducting a surgery and surgical education. Thus, a novel CAS system will contribute to not only the performance of reliable hepatectomy but also to surgical education.

  5. Airway branching morphogenesis in three dimensional culture

    Directory of Open Access Journals (Sweden)

    Gudjonsson Thorarinn

    2010-11-01

    Full Text Available Abstract Background Lungs develop from the fetal digestive tract where epithelium invades the vascular rich stroma in a process called branching morphogenesis. In organogenesis, endothelial cells have been shown to be important for morphogenesis and the maintenance of organ structure. The aim of this study was to recapitulate human lung morphogenesis in vitro by establishing a three dimensional (3D co-culture model where lung epithelial cells were cultured in endothelial-rich stroma. Methods We used a human bronchial epithelial cell line (VA10 recently developed in our laboratory. This cell line cell line maintains a predominant basal cell phenotype, expressing p63 and other basal markers such as cytokeratin-5 and -14. Here, we cultured VA10 with human umbilical vein endothelial cells (HUVECs, to mimic the close interaction between these cell types during lung development. Morphogenesis and differentiation was monitored by phase contrast microscopy, immunostainings and confocal imaging. Results We found that in co-culture with endothelial cells, the VA10 cells generated bronchioalveolar like structures, suggesting that lung epithelial branching is facilitated by the presence of endothelial cells. The VA10 derived epithelial structures display various complex patterns of branching and show partial alveolar type-II differentiation with pro-Surfactant-C expression. The epithelial origin of the branching VA10 colonies was confirmed by immunostaining. These bronchioalveolar-like structures were polarized with respect to integrin expression at the cell-matrix interface. The endothelial-induced branching was mediated by soluble factors. Furthermore, fibroblast growth factor receptor-2 (FGFR-2 and sprouty-2 were expressed at the growing tips of the branching structures and the branching was inhibited by the FGFR-small molecule inhibitor SU5402. Discussion In this study we show that a human lung epithelial cell line can be induced by endothelial cells to

  6. [Precision of three-dimensional printed brackets].

    Science.gov (United States)

    Zhang, D; Wang, L C; Zhou, Y H; Liu, X M; Li, J

    2017-08-18

    This study was based on digital orthodontic diagnosis work flow for indirect bonding transfer tray model design and three-dimensional (3D) printing, and the aim of this paper was to inspect the dimensional accuracyof 3D printed brackets, which is the foundation of the follow up work and hoped that will illuminate the clinical application of the digital orthodontics work flow. The samples which consisted of 14 cases of patients with malocclusion from Department of Orthodontics Peking University were selected, including 8 cases with tooth extraction and 6 cases without tooth extraction. All the 14 patients were taken intra-oral scan (Trios 3Shape, Denmark) and cone-beam computed tomography (CBCT, NewTom 3G volumetric scanner, Aperio Service,Italy)shooting after periodontal treatment. STL data and DICOM data were obtained from intraoral scans and CBCT images.Data segmentation, registration, fusion, automatic tooth arrangement, virtual positioning of orthodontic appliance and conversion the coordinates of malocclusion model were all done with self-programming software. The data of 3D printing model with brackets on it were output finally and printed out with EDEN260V (Objet Geometries, Israel) to make indirect bonding transfer tray. Digital vernier caliper was used to measure the length and width of upper and lower left brackets and buccal tubes on those 3D models after removal of surrounding supporting material by ultrasonic vibration and water-spray. Intra-examiner reliability was assessed by using intra-class correlation coefficients (ICC), and one-sample T test was used to compare the measurements with the standard dimensional data of the brackets. There were significant differences which range in 0.04-0.17 mm between the 13 items out of the 19 measurement items. Except for the length of the lower left premolars'brackets, mean values of the other items were greater than the test value. Although the measurement results in the width of brackets and the width and

  7. Three-dimensional seismic depth migration

    Science.gov (United States)

    Zhou, Hongbo

    1998-12-01

    filters are incorporated into 3-D one-way frequency-space depth migration for evanescent energy removal and for phase compensation of splitting errors; a single filter achieves both goals. Synthetic examples illustrate the behavior of the parallel filters. For a given order of filter, the cost of the Butterworth and Chebyshev filters is the same. A Chebyshev filter is more effective for phase compensation than the Butterworth filter of the same order, at the expense of some wavenumber-dependent amplitude ripples. An analytical formula for geometrical spreading is derived for a horizontally layered transversely isotropic medium with a vertical symmetry axis. Under this expression, geometrical spreading can be determined only by the anisotropic parameters in the first layer, the traveltime derivatives, and source-receiver offset. An explicit, numerically feasible expression for geometrical spreading can be further obtained by considering some of the special cases of transverse isotropy, such as weak anisotropy or elliptic anisotropy. Therefore, with the techniques of non-hyerbolic moveout for transverse isotropic media, geometrical spreading can be calculated by using picked traveltimes of primary P-wave reflections without having to know the actual parameters in the deeper subsurface; no ray tracing is needed. Synthetic examples verify the algorithm and show that it is numerically feasible for calculation of geometrical spreading.

  8. [Preparation of simulate craniocerebral models via three dimensional printing technique].

    Science.gov (United States)

    Lan, Q; Chen, A L; Zhang, T; Zhu, Q; Xu, T

    2016-08-09

    Three dimensional (3D) printing technique was used to prepare the simulate craniocerebral models, which were applied to preoperative planning and surgical simulation. The image data was collected from PACS system. Image data of skull bone, brain tissue and tumors, cerebral arteries and aneurysms, and functional regions and relative neural tracts of the brain were extracted from thin slice scan (slice thickness 0.5 mm) of computed tomography (CT), magnetic resonance imaging (MRI, slice thickness 1mm), computed tomography angiography (CTA), and functional magnetic resonance imaging (fMRI) data, respectively. MIMICS software was applied to reconstruct colored virtual models by identifying and differentiating tissues according to their gray scales. Then the colored virtual models were submitted to 3D printer which produced life-sized craniocerebral models for surgical planning and surgical simulation. 3D printing craniocerebral models allowed neurosurgeons to perform complex procedures in specific clinical cases though detailed surgical planning. It offered great convenience for evaluating the size of spatial fissure of sellar region before surgery, which helped to optimize surgical approach planning. These 3D models also provided detailed information about the location of aneurysms and their parent arteries, which helped surgeons to choose appropriate aneurismal clips, as well as perform surgical simulation. The models further gave clear indications of depth and extent of tumors and their relationship to eloquent cortical areas and adjacent neural tracts, which were able to avoid surgical damaging of important neural structures. As a novel and promising technique, the application of 3D printing craniocerebral models could improve the surgical planning by converting virtual visualization into real life-sized models.It also contributes to functional anatomy study.

  9. The Three-dimensional Digital Factory for Shipbuilding Technology Research

    Directory of Open Access Journals (Sweden)

    Xu Wei

    2016-01-01

    Full Text Available The three-dimensional digital factory technology research is the hotspot in shipbuilding recently. The three-dimensional digital factory technology not only focus on design the components of the product, but also discuss on the simulation and analyses of the production process.Based on the three-dimensional model, the basic data layer, application control layer and the presentation layer of hierarchical structure are established in the three-dimensional digital factory of shipbuilding in this paper. And the key technologies of three-dimensional digital factory of shipbuilding are analysed. Finally, a case study is applied and the results show that the three-dimensional digital factory will play an important role in the future.

  10. Three-dimensional reconstructions in neuroanatomy

    International Nuclear Information System (INIS)

    Kretschmann, H.J.; Vogt, H.; Schuetz, T.; Gerke, M.; Riedel, A.; Buhmann, C.; Wesemann, M.; Mueller, D.

    1991-01-01

    Computer-aided 3D reconstructions of neurofunctional systems and structures are generated as a reference for neuroimaging (CT, MRI, PET). The clinical application of these 3D reconstructions requires a coordinate system and conditions resembling the intravital neuroanatomy as far as possible. In this paper the neuroanatomical reference system (NeuRef) of the Department of Neuroanatomy of Hannover Medical School is presented. This consists of methods to record brain structures from serial sections with minimal error (less than 1 mm) and to display 3D brain models derived from such a data base. In addition, NeuRef is able to generate sections through, for instance, the visual and pyramidal system and to transfer these data onto a corresponcing CT image. Therefore, this method can serve as a diagnostic aid in neuroradiology, in operation planning, and radiotherapy. It can also be used in PACS. (orig.) [de

  11. Nested structures approach in designing an isotropic negative-index material for infrared

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Malureanu, Radu; Lavrinenko, Andrei

    2009-01-01

    We propose a new generic approach for designing isotropic metamaterial with nested cubic structures. As an example, a three-dimensional isotropic unit cell design "Split Cube in Cage" (SCiC) is shown to exhibit an effective negative refractive index on infrared wavelengths. We report on the refra......We propose a new generic approach for designing isotropic metamaterial with nested cubic structures. As an example, a three-dimensional isotropic unit cell design "Split Cube in Cage" (SCiC) is shown to exhibit an effective negative refractive index on infrared wavelengths. We report...

  12. Three-dimensional reconstruction of the biliary tract using spiral computed tomography. Three-dimensional cholangiography

    International Nuclear Information System (INIS)

    Gon, Masanori; Ogura, Norihiro; Uetsuji, Shouji; Ueyama, Yasuo

    1995-01-01

    In this study, 310 patients with benign biliary diseases, 20 with gallbladder cancer, and 8 with biliary tract carcinoma underwent spiral CT (SCT) scanning at cholangiography. Depiction rate of the shape of the conjunction site of the gallbladder and biliary tract was 27.5% by conventional intravenous cholangiography (DIC), 92.5% by ERC, and 90.0% by DIC-SCT. Abnormal cystic duct course was admitted in 14.1%. Multiplanar reconstruction by DIC-SCT enabled identification of the common bile duct and intrahepatic bile duct stone. Three-dimensional reconstruction of DIC-SCT was effective in evaluating obstruction of the anastomosis or passing condition of after hepatico-jejunostomy. Two-dimensional SCT images through PTCD tube enabled degree of hepatic invasion in bile duct cancer, and three-dimensional images were useful in grasping the morphology of the bile duct branches near the obstruction site. DIC-SCT is therefore considered a useful procedure as non-invasive examination of bile duct lesions. (S.Y.)

  13. Analytical three-dimensional neutron transport benchmarks for verification of nuclear engineering codes. Final report

    International Nuclear Information System (INIS)

    Ganapol, B.D.; Kornreich, D.E.

    1997-01-01

    Because of the requirement of accountability and quality control in the scientific world, a demand for high-quality analytical benchmark calculations has arisen in the neutron transport community. The intent of these benchmarks is to provide a numerical standard to which production neutron transport codes may be compared in order to verify proper operation. The overall investigation as modified in the second year renewal application includes the following three primary tasks. Task 1 on two dimensional neutron transport is divided into (a) single medium searchlight problem (SLP) and (b) two-adjacent half-space SLP. Task 2 on three-dimensional neutron transport covers (a) point source in arbitrary geometry, (b) single medium SLP, and (c) two-adjacent half-space SLP. Task 3 on code verification, includes deterministic and probabilistic codes. The primary aim of the proposed investigation was to provide a suite of comprehensive two- and three-dimensional analytical benchmarks for neutron transport theory applications. This objective has been achieved. The suite of benchmarks in infinite media and the three-dimensional SLP are a relatively comprehensive set of one-group benchmarks for isotropically scattering media. Because of time and resource limitations, the extensions of the benchmarks to include multi-group and anisotropic scattering are not included here. Presently, however, enormous advances in the solution for the planar Green's function in an anisotropically scattering medium have been made and will eventually be implemented in the two- and three-dimensional solutions considered under this grant. Of particular note in this work are the numerical results for the three-dimensional SLP, which have never before been presented. The results presented were made possible only because of the tremendous advances in computing power that have occurred during the past decade

  14. New method for solving three-dimensional Schroedinger equation

    International Nuclear Information System (INIS)

    Melezhik, V.S.

    1990-01-01

    The method derived recently for solving a multidimensional scattering problem is applied to a three-dimensional Schroedinger equation. As compared with direct three-dimensional calculations of finite elements and finite differences, this approach gives sufficiently accurate upper and lower approximations to the helium-atom binding energy, which demonstrates its efficiency. 15 refs.; 1 fig.; 2 tabs

  15. Three-dimensional low-energy topological invariants

    International Nuclear Information System (INIS)

    Bakalarska, M.; Broda, B.

    2000-01-01

    A description of the one-loop approximation formula for the partition function of a three-dimensional abelian version of the Donaldson-Witten theory is proposed. The one-loop expression is shown to contain such topological invariants of a three-dimensional manifold M like the Reidemeister-Ray-Singer torsion τ R and Betti numbers. (orig.)

  16. Collapse in a forced three-dimensional nonlinear Schrodinger equation

    DEFF Research Database (Denmark)

    Lushnikov, P.M.; Saffman, M.

    2000-01-01

    We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation.......We derive sufficient conditions for the occurrence of collapse in a forced three-dimensional nonlinear Schrodinger equation without dissipation. Numerical studies continue the results to the case of finite dissipation....

  17. Three-dimensional plasma equilibrium near a separatrix

    International Nuclear Information System (INIS)

    Reiman, A.H.; Pomphrey, N.; Boozer, A.H.

    1988-08-01

    The limiting behavior of a general three-dimensional MHD equilibrium near a separatrix is calculated explicitly. No expansions in β or assumptions about island widths are made. Implications of the results for the numerical calculation of such equilibria, are discussed, as well as for issues concerning the existence of three-dimensional MHD equilibria. 16 refs., 2 figs

  18. Three dimensional periodic foundations for base seismic isolation

    International Nuclear Information System (INIS)

    Yan, Y; Mo, Y L; Cheng, Z; Shi, Z; Menq, F; Tang, Y

    2015-01-01

    Based on the concept of phononic crystals, periodic foundations made of periodic materials are investigated in this paper. The periodic foundations can provide low frequency band gaps, which cover the main frequency ranges of seismic waves. Therefore, the periodic foundations are able to protect the upper structures during earthquake events. In this paper, the basic theory of three dimensional periodic foundations is studied and the finite element method was used to conduct the sensitivity study. A simplified three-dimensional periodic foundation with a superstructure was tested in the field and the feasibility of three dimensional periodic foundations was proved. The test results showed that the response of the upper structure with the three dimensional periodic foundation was reduced under excitation waves with the main frequency falling in the attenuation zones. The finite element analysis results are consistent with the experimental data, indicating that three dimensional periodic foundations are a feasible way of reducing seismic vibrations. (paper)

  19. Magnetic resonance imaging and three-dimensional ultrasound of carotid atherosclerosis: mapping regional differences.

    Science.gov (United States)

    Krasinski, Adam; Chiu, Bernard; Fenster, Aaron; Parraga, Grace

    2009-04-01

    To evaluate differences in carotid atherosclerosis measured using magnetic resonance imaging (MRI) and three-dimensional ultrasound (3DUS). Ten subject volunteers underwent carotid 3DUS and MRI (multislice black blood fast spin echo, T1-weighted contrast, double inversion recovery, 0.5 mm in-plane resolution, 2 mm slice, 3.0 T) within 1 hour. 3DUS and MR images were manually segmented by two observers providing vessel wall and lumen contours for quantification of vessel wall volume (VWV) and generation of carotid thickness maps. MRI VWV (1040 +/- 210 mm(3)) and 3DUS VWV (540 +/- 110 mm(3)) were significantly different (P Power Doppler US confirmed that heterogeneity in the common carotid artery in all patients resulted from apparent flow disturbances, not atherosclerotic plaque. MRI and 3DUS VWV were significantly different and carotid maps showed homogeneous thickness differences and heterogeneity in specific regions of interest identified as MR flow artifacts in the common carotid artery.

  20. Three dimensional image presentation techniques in medical imaging

    International Nuclear Information System (INIS)

    Pizer, S.M.; Fuchs, H.

    1987-01-01

    Medical images can be presented three-dimensionally by techniques that either calculate the effect of reflections from surfaces predefined from slices or project a three-space of luminosities computed from voxel intensities onto the visual receptors. Sliced-based reflective displays are the most common type. Means of producing surface descriptions both via voxel sets and via slice contours are reviewed. Advantages of and means of transparent display to allow the appreciation of the 3D relationships among objects are set forth. Ways to produce additional depth cues by stereoscopy and the kinetic depth effect are discussed, and the importance of interactive modification of viewpoint, clipping plane, displayed objects, etc. are explained. A new device, UNC's Pixel-planes, for accomplishing this in real time are illustrated. Voxel intensity based display methods avoid the need for time-consuming predefinition of object surfaces and thus can allow exploration of 3D image data. Varifocal mirror hardware and fast computation of one or more projections based on object probabilities are two of the more important approaches. While 3D display provides important information about 3D relationships, it cannot provide the kind of appreciation of subtle grey-scale changes that 2D display can. Methods that can combine these two kinds of information by superimposing 2D grey-scale slices on or in the context of 3D displays are discussed. Applications of these techniques for both diagnosis and radiotherapy planning are used as illustrations and guides to the usefulness of these techniques with CT, MRI, and other 3D medical imaging modalities. 24 refs.; 5 figs

  1. Development of a three-dimensional radiation dosimetry system

    International Nuclear Information System (INIS)

    Bero, M.A.

    2001-12-01

    The direct non-destructive measurement of the radiation absorbed dose in three dimensions is considered to be technically difficult. Accurate determination of the spatial distribution of absorbed dose plays an important role in many applications particularly in medicine. In radiotherapy computer calculations are frequently used to estimate three-dimensional dose distributions in complex geometry, hence a practical dosimetry system able to provide three-dimensional (3-D) integrated measurements is highly desirable for verifying such dose predictions. Magnetic Resonance Imaging (MRI) has been used to visualise 3-D dose distributions, inside two different detector materials, namely the ferrous sulphate gel (Fricke gel) and the polymer gel system. Each of these procedures has its own drawbacks and limitations, and this research project sought to find improvements and alternatives to overcome these problems. Work on the Fricke gel led to an improved preparation procedure employing gelatin gel whose lower melting point reduces the possibility of dissolved oxygen loss. The role of each component was clarified which led to the omission of all unnecessary chemicals such as the sodium chloride and benzoic acid. Initially MRI was the only 3-D readout technique available, however simple relaxometry was used to characterise the detector quantitatively with each modification before employing an MRI scanner to obtain images. Optimisation of the active constituents saves time and effort, and minimises the cost of equipment as well as materials. A serious drawback of the Fricke gel is ion diffusion, which causes blurring of the recorded spatial distribution and much effort was given to attempts to reduce this. However it was concluded that it is possible to slow down ion diffusion but at the cost of detector sensitivity. Therefore the best way of dealing with this problem is by introducing a fast readout technique so that the dose distribution can be recorded before serious

  2. Cylindrical Three-Dimensional Porous Anodic Alumina Networks

    Directory of Open Access Journals (Sweden)

    Pedro M. Resende

    2016-11-01

    Full Text Available The synthesis of a conformal three-dimensional nanostructure based on porous anodic alumina with transversal nanopores on wires is herein presented. The resulting three-dimensional network exhibits the same nanostructure as that obtained on planar geometries, but with a macroscopic cylindrical geometry. The morphological analysis of the nanostructure revealed the effects of the initial defects on the aluminum surface and the mechanical strains on the integrity of the three-dimensional network. The results evidence the feasibility of obtaining 3D porous anodic alumina on non-planar aluminum substrates.

  3. Diffraction limited focusing with controllable arbitrary three-dimensional polarization

    International Nuclear Information System (INIS)

    Chen, Weibin; Zhan, Qiwen

    2010-01-01

    We propose a new approach that enables full control over the three-dimensional state of polarization and the field distribution near the focus of a high numerical aperture objective lens. By combining the electric dipole radiation and a vectorial diffraction method, the input field at the pupil plane for generating arbitrary three-dimensionally oriented linear polarization at the focal point with a diffraction limited spot size is found analytically by solving the inverse problem. Arbitrary three-dimensional elliptical polarization can be obtained by introducing a second electric dipole oriented in the orthogonal plane with appropriate amplitude and phase differences

  4. Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

    Energy Technology Data Exchange (ETDEWEB)

    Rasche, Volker [University of Ulm, Department of Internal Medicine II, Ulm (Germany); Philips Medical Systems, Bothell, WA (United States); Mansour, Moussa; Reddy, Vivek; Singh, Jagmeet P.; Ruskin, Jeremy [Massachusetts General Hospital, Harvard Medical School, Cardiac Arrhythmia Service, Boston, MA (United States); Qureshi, Answer [Massachusetts General Hospital, Harvard Medical School, Echocardiography, Boston, MA (United States); Manzke, Robert; Sokka, Sham [Philips Research North America, Clinical Sites Research, Briacliff Manor, NY (United States)

    2008-03-15

    Cardiovascular intervention guidance requires knowledge of heart function relative to its blood supply or venous drainage. Functional and vascular anatomic data are usually generated on different imaging systems, so fusion of the data is necessary to simultaneously visualize the results for intervention planning and guidance. The objective of this work is to establish the feasibility of fusing volumetric ultrasound (U/S) data with three-dimensional (3D) X-ray imaging data for visualization of cardiac morphology, function and coronary venous drainage. Temporally resolved U/S volume data was registered with the 3D reconstruction of vascular structures derived from X-ray modeling and reconstruction. U/S image registration was obtained by optical tracking fiducial markers with simultaneous X-ray imaging. The proposed technique was applied to phantom data for accuracy assessment of the registration process and to biventricular pacemaker implantation as clinical example. Fusion of U/S data with 3D X-ray reconstruction data produced an RMS registration error below 2 mm. Preliminary clinical feasibility of U/S-derived data synchronously with X-ray derived 3D coronary venography was established. This technique can be applied for fusion of functional U/S data with 3D anatomic X-ray data of the coronary veins during a biventricular pacemaker implantation procedures. (orig.)

  5. Three-dimensional modelling and three-dimensional printing in pediatric and congenital cardiac surgery.

    Science.gov (United States)

    Kiraly, Laszlo

    2018-04-01

    Three-dimensional (3D) modelling and printing methods greatly support advances in individualized medicine and surgery. In pediatric and congenital cardiac surgery, personalized imaging and 3D modelling presents with a range of advantages, e.g., better understanding of complex anatomy, interactivity and hands-on approach, possibility for preoperative surgical planning and virtual surgery, ability to assess expected results, and improved communication within the multidisciplinary team and with patients. 3D virtual and printed models often add important new anatomical findings and prompt alternative operative scenarios. For the lack of critical mass of evidence, controlled randomized trials, however, most of these general benefits remain anecdotal. For an individual surgical case-scenario, prior knowledge, preparedness and possibility of emulation are indispensable in raising patient-safety. It is advocated that added value of 3D printing in healthcare could be raised by establishment of a multidisciplinary centre of excellence (COE). Policymakers, research scientists, clinicians, as well as health care financers and local entrepreneurs should cooperate and communicate along a legal framework and established scientific guidelines for the clinical benefit of patients, and towards financial sustainability. It is expected that besides the proven utility of 3D printed patient-specific anatomical models, 3D printing will have a major role in pediatric and congenital cardiac surgery by providing individually customized implants and prostheses, especially in combination with evolving techniques of bioprinting.

  6. Fusion of three-dimensional X-ray angiography and three-dimensional echocardiography

    International Nuclear Information System (INIS)

    Rasche, Volker; Mansour, Moussa; Reddy, Vivek; Singh, Jagmeet P.; Ruskin, Jeremy; Qureshi, Answer; Manzke, Robert; Sokka, Sham

    2008-01-01

    Cardiovascular intervention guidance requires knowledge of heart function relative to its blood supply or venous drainage. Functional and vascular anatomic data are usually generated on different imaging systems, so fusion of the data is necessary to simultaneously visualize the results for intervention planning and guidance. The objective of this work is to establish the feasibility of fusing volumetric ultrasound (U/S) data with three-dimensional (3D) X-ray imaging data for visualization of cardiac morphology, function and coronary venous drainage. Temporally resolved U/S volume data was registered with the 3D reconstruction of vascular structures derived from X-ray modeling and reconstruction. U/S image registration was obtained by optical tracking fiducial markers with simultaneous X-ray imaging. The proposed technique was applied to phantom data for accuracy assessment of the registration process and to biventricular pacemaker implantation as clinical example. Fusion of U/S data with 3D X-ray reconstruction data produced an RMS registration error below 2 mm. Preliminary clinical feasibility of U/S-derived data synchronously with X-ray derived 3D coronary venography was established. This technique can be applied for fusion of functional U/S data with 3D anatomic X-ray data of the coronary veins during a biventricular pacemaker implantation procedures. (orig.)

  7. Fabrication of malleable three-dimensional-printed customized bolus using three-dimensional scanner.

    Directory of Open Access Journals (Sweden)

    Jae Won Park

    Full Text Available A three-dimensional (3D-printed customized bolus (3D bolus can be used for radiotherapy application to irregular surfaces. However, bolus fabrication based on computed tomography (CT scans is complicated and also delivers unwanted irradiation. Consequently, we fabricated a bolus using a 3D scanner and evaluated its efficacy. The head of an Alderson Rando phantom was scanned with a 3D scanner. The 3D surface data were exported and reconstructed with Geomagic Design X software. A 3D bolus of 5-mm thickness designed to fit onto the nose was printed with the use of rubber-like printing material, and a radiotherapy plan was developed. We successfully fabricated the customized 3D bolus, and further, a CT simulation indicated an acceptable fit of the 3D bolus to the nose. There was no air gap between the bolus and the phantom surface. The percent depth dose (PDD curve of the phantom with the 3D bolus showed an enhanced surface dose when compared with that of the phantom without the bolus. The PDD of the 3D bolus was comparable with that of a commercial superflab bolus. The radiotherapy plan considering the 3D bolus showed improved target coverage when compared with that without the bolus. Thus, we successfully fabricated a customized 3D bolus for an irregular surface using a 3D scanner instead of a CT scanner.

  8. Progress of radiotherapy by three-dimensional treatment planning

    International Nuclear Information System (INIS)

    Imada, Hajime; Nomoto, Satoshi; Takahashi, Hiroyuki; Nakata, Hajime

    1998-01-01

    The recent progress of three-dimensional radiation treatment planning was reviewed. And clinical cases such as lung cancer and breast cancer are introduced. In the University of Occupational and Development Health, the treatment system FOCUS which is made up of CT simulator and linac was used mainly. Three-dimensional treatment planning was carried for about 90% of 330 patients who underwent radiotherapy for one year. The target becomes to be accurate and dose distribution with all CT slices in radiation field can be confirmed by using three-dimensional radiation treatment planning apparatus. High dose irradiation localized to tumor part is possible. Relations between total dose and volume of normal tissue and/or tumor can be estimated numerically and easily by DVH. A prediction of indication and affection became possible by this procedure. In conclusion, generalization of three-dimensional radiation treatment planning will bring progress of more effective radiotherapy with less adverse reaction. (K.H.). 21 refs

  9. Feynman diagrams coupled to three-dimensional quantum gravity

    International Nuclear Information System (INIS)

    Barrett, John W

    2006-01-01

    A framework for quantum field theory coupled to three-dimensional quantum gravity is proposed. The coupling with quantum gravity regulates the Feynman diagrams. One recovers the usual Feynman amplitudes in the limit as the cosmological constant tends to zero

  10. Three-dimensional reconstruction and visualization system for medical images

    International Nuclear Information System (INIS)

    Preston, D.F.; Batnitzky, S.; Kyo Rak Lee; Cook, P.N.; Cook, L.T.; Dwyer, S.J.

    1982-01-01

    A three-dimensional reconstruction and visualization system could be of significant advantage in medical application such as neurosurgery and radiation treatment planning. The reconstructed anatomic structures from CT head scans could be used in a head stereotactic system to help plan the surgical procedure and the radiation treatment for a brain lesion. Also, the use of three-dimensional reconstruction algorithm provides for quantitative measures such as volume and surface area estimation of the anatomic features. This aspect of the three-dimensional reconstruction system may be used to monitor the progress or staging of a disease and the effects of patient treatment. Two cases are presented to illustrate the three-dimensional surface reconstruction and visualization system

  11. Three dimensional CT imaging of ossicular chain: a preliminary study

    International Nuclear Information System (INIS)

    Hu Chunhong; Zhong Shenbin; Fu Yindi; Zhu Wei; Wang Xueyuan; Chen Jianhua; Ding Yi

    2001-01-01

    Objective: To analysis the features of normal and abnormal ossicular chain in three dimensional images and asses the best parameters and its usefulness in diagnosis and treatment of chronic otitis media (COM). Methods: All patients, including 43 patients with normal ears and 24 ears with COM, were examined using spiral CT with inner ear software, 1-mm slice width and 1 pitch. SSD method was used in three dimensional reconstruction and the threshold was 100-300 Hu. Results: In normal cases, Malleus, incus, stapes crura, incudomalleal joints and incudostapedial joints were displayed well, but stapes footplate unsatisfactorily. The disruption of the ossicular chain showed in three-dimensional images in cases of chronic otitis media was in accord with that seen in the operation. Conclusion: It is very important for imaging with high quality through selecting proper parameters, and three-dimensional image can provide valuable information for surgery

  12. Analysis and validation of carbohydrate three-dimensional structures

    International Nuclear Information System (INIS)

    Lütteke, Thomas

    2009-01-01

    The article summarizes the information that is gained from and the errors that are found in carbohydrate structures in the Protein Data Bank. Validation tools that can locate these errors are described. Knowledge of the three-dimensional structures of the carbohydrate molecules is indispensable for a full understanding of the molecular processes in which carbohydrates are involved, such as protein glycosylation or protein–carbohydrate interactions. The Protein Data Bank (PDB) is a valuable resource for three-dimensional structural information on glycoproteins and protein–carbohydrate complexes. Unfortunately, many carbohydrate moieties in the PDB contain inconsistencies or errors. This article gives an overview of the information that can be obtained from individual PDB entries and from statistical analyses of sets of three-dimensional structures, of typical problems that arise during the analysis of carbohydrate three-dimensional structures and of the validation tools that are currently available to scientists to evaluate the quality of these structures

  13. Three-dimensional Simulation of Backward Raman Amplification

    International Nuclear Information System (INIS)

    Balakin, A.A.; Fraiman, G.M.; Fisch, N.J.

    2005-01-01

    Three-dimensional (3-D) simulations for the Backward Raman Amplification (BRA) are presented. The images illustrate the effects of pump depletion, pulse diffraction, non-homogeneous plasma density, and plasma ionization

  14. Magnetic structure of two- and three-dimensional supramolecular compounds

    Energy Technology Data Exchange (ETDEWEB)

    Decurtins, S.; Schmalle, H.W.; Pellaux, R. [Zurich Univ. (Switzerland); Fischer, P.; Fauth, F. [Paul Scherrer Inst. (PSI), Villigen (Switzerland); Ouladdiaf, B. [Institut Max von Laue - Paul Langevin, 75 - Paris (France)

    1997-09-01

    Supramolecular chiral networks of oxalato-bridged transition metals show either two- or three-dimensional structural features. The magnetic structures of such compounds have been investigated by means of elastic neutron powder diffraction. (author) 2 figs., 2 refs.

  15. Three-Dimensional scanning transmission electron microscopy of biological specimens

    KAUST Repository

    De Jonge, Niels; Sougrat, Rachid; Northan, Brian M.; Pennycook, Stephen J.

    2010-01-01

    A three-dimensional (3D) reconstruction of the cytoskeleton and a clathrin-coated pit in mammalian cells has been achieved from a focal-series of images recorded in an aberration-corrected scanning transmission electron microscope (STEM

  16. [Bone drilling simulation by three-dimensional imaging].

    Science.gov (United States)

    Suto, Y; Furuhata, K; Kojima, T; Kurokawa, T; Kobayashi, M

    1989-06-01

    The three-dimensional display technique has a wide range of medical applications. Pre-operative planning is one typical application: in orthopedic surgery, three-dimensional image processing has been used very successfully. We have employed this technique in pre-operative planning for orthopedic surgery, and have developed a simulation system for bone-drilling. Positive results were obtained by pre-operative rehearsal; when a region of interest is indicated by means of a mouse on the three-dimensional image displayed on the CRT, the corresponding region appears on the slice image which is displayed simultaneously. Consequently, the status of the bone-drilling is constantly monitored. In developing this system, we have placed emphasis on the quality of the reconstructed three-dimensional images, on fast processing, and on the easy operation of the surgical planning simulation.

  17. Standalone visualization tool for three-dimensional DRAGON geometrical models

    International Nuclear Information System (INIS)

    Lukomski, A.; McIntee, B.; Moule, D.; Nichita, E.

    2008-01-01

    DRAGON is a neutron transport and depletion code able to solve one-, two- and three-dimensional problems. To date DRAGON provides two visualization modules, able to represent respectively two- and three-dimensional geometries. The two-dimensional visualization module generates a postscript file, while the three dimensional visualization module generates a MATLAB M-file with instructions for drawing the tracks in the DRAGON TRACKING data structure, which implicitly provide a representation of the geometry. The current work introduces a new, standalone, tool based on the open-source Visualization Toolkit (VTK) software package which allows the visualization of three-dimensional geometrical models by reading the DRAGON GEOMETRY data structure and generating an axonometric image which can be manipulated interactively by the user. (author)

  18. Study of three-dimensional image display by systemic CT

    International Nuclear Information System (INIS)

    Fujioka, Tadao; Ebihara, Yoshiyuki; Unei, Hiroshi; Hayashi, Masao; Shinohe, Tooru; Wada, Yuji; Sakai, Takatsugu; Kashima, Kenji; Fujita, Yoshihiro

    1989-01-01

    A head phantom for CT was scanned at 2 mm intervals from the cervix to the vertex in an attempt to obtain a three-dimensional image display of bones and facial epidermis from an ordinary axial image. Clinically, three-dimensional images were formed at eye sockets and hip joints. With the three-dimensional image using the head phantom, the entire head could be displayed at any angle. Clinically, images were obtained that could not be attained by ordinary CT scanning, such as broken bones in eye sockets and stereoscopic structure at the bottom of a cranium. The three-dimensional image display is considered to be useful in clinical diagnosis. (author)

  19. Three-Dimensional Structure Determination of Botulinum Toxin

    National Research Council Canada - National Science Library

    Stevens, Ray

    1997-01-01

    ...) Based on the structure of the neurotoxin, understand the toxins mechanism of action. We have accomplished the first goal of determining the three-dimensional structure of the 150 kD botulinum neurotoxin serotype...

  20. Three-Dimensional Structure Determination of Botulinum Toxin

    National Research Council Canada - National Science Library

    Stevens, Ray

    1998-01-01

    ...) Based on the structure of the neurotoxin, understand the toxins mechanism of action. We have accomplished the first goal of determining the three-dimensional structure of the 150 kD botulinum neurotoxin serotype...

  1. Direct Linear Transformation Method for Three-Dimensional Cinematography

    Science.gov (United States)

    Shapiro, Robert

    1978-01-01

    The ability of Direct Linear Transformation Method for three-dimensional cinematography to locate points in space was shown to meet the accuracy requirements associated with research on human movement. (JD)

  2. A simple remark on three dimensional gauge theories

    International Nuclear Information System (INIS)

    Lemes, V.E.R.; Linhares de Jesus, C.; Sasaki, C.A.G.; Sorella, S.P.; Vilar, L.C.Q.; Ventura, O.S.

    1997-08-01

    Classical three dimensional Yang-Mills is seen to be related to the topological Chern-Simons term through a nonlinear but fully local and covariant gauge field redefinition. A classical recursive cohomological argument is proved. (author)

  3. Computational study of three-dimensional wake structure

    International Nuclear Information System (INIS)

    Himeno, R.; Shirayama, S.; Kamo, K.; Kuwahara, K.

    1986-01-01

    Three-dimensional wake structure is studied by numerically solving the incompressible Navier-Stokes equations. Results are visualized by a three-dimensional color graphic system. It was found that a pair of vortex tubes separated from a body plays the most important role in the wake. Near the body vortex tubes are rather stable, however, they gradually become unsteady as they flow down

  4. Three-dimensional magnetophotonic crystals based on artificial opals

    Science.gov (United States)

    Baryshev, A. V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

    2004-06-01

    We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties.

  5. Three-dimensional magnetophotonic crystals based on artificial opals

    International Nuclear Information System (INIS)

    Baryshev, A.V.; Kodama, T.; Nishimura, K.; Uchida, H.; Inoue, M.

    2004-01-01

    We fabricated and experimentally investigated three-dimensional magnetophotonic crystals (3D MPCs) based on artificial opals. Opal samples with three-dimensional dielectric lattices were impregnated with different types of magnetic material. Magnetic and structural properties of 3D MPCs were studied by field emission scanning electron microscopy, x-ray diffraction analysis, and vibrating sample magnetometer. We have shown that magnetic materials synthesized in voids of opal lattices and the composites obtained have typical magnetic properties

  6. Three-dimensional transesophageal echocardiography of the atrial septal defects

    Directory of Open Access Journals (Sweden)

    Romero-Cárdenas Ángel

    2008-07-01

    Full Text Available Abstract Transesophageal echocardiography has advantages over transthoracic technique in defining morphology of atrial structures. Even though real time three-dimensional echocardiographic imaging is a reality, the off-line reconstruction technique usually allows to obtain higher spatial resolution images. The purpose of this study was to explore the accuracy of off-line three-dimensional transesophageal echocardiography in a spectrum of atrial septal defects by comparing them with representative anatomic specimens.

  7. Comparison of two three-dimensional cephalometric analysis computer software

    OpenAIRE

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-01-01

    Background: Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Materials and Methods: Twenty cone beam computed tomography images were obtained using i-CAT® imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (Unive...

  8. Simulation on three dimensional bubble formation using MARS

    International Nuclear Information System (INIS)

    Kunugi, Tomoaki

    1997-01-01

    This paper describes a numerical simulation on three-dimensional bubble formation by means of the MARS (Multi-interfaces Advection and Reconstruction Solver) developed by the author. The comparison between two-dimensional and three-dimensional simulation on an agglomeration of two bubbles is discussed. Moreover, some simulation results regarding a phase change phenomena such as a boiling and condensation in a two dimensional enclosure with heated and cooled walls are presented. (author)

  9. Three-dimensional stellarator equilibrium as an ohmic steady state

    International Nuclear Information System (INIS)

    Park, W.; Monticello, D.A.; Strauss, H.; Manickam, J.

    1985-07-01

    A stable three-dimensional stellarator equilibrium can be obtained numerically by a time-dependent relaxation method using small values of dissipation. The final state is an ohmic steady state which approaches an ohmic equilibrium in the limit of small dissipation coefficients. We describe a method to speed up the relaxation process and a method to implement the B vector . del p = 0 condition. These methods are applied to obtain three-dimensional heliac equilibria using the reduced heliac equations

  10. Discretization model for nonlinear dynamic analysis of three dimensional structures

    International Nuclear Information System (INIS)

    Hayashi, Y.

    1982-12-01

    A discretization model for nonlinear dynamic analysis of three dimensional structures is presented. The discretization is achieved through a three dimensional spring-mass system and the dynamic response obtained by direct integration of the equations of motion using central diferences. First the viability of the model is verified through the analysis of homogeneous linear structures and then its performance in the analysis of structures subjected to impulsive or impact loads, taking into account both geometrical and physical nonlinearities is evaluated. (Author) [pt

  11. Advancing three-dimensional MEMS by complimentary laser micro manufacturing

    Science.gov (United States)

    Palmer, Jeremy A.; Williams, John D.; Lemp, Tom; Lehecka, Tom M.; Medina, Francisco; Wicker, Ryan B.

    2006-01-01

    This paper describes improvements that enable engineers to create three-dimensional MEMS in a variety of materials. It also provides a means for selectively adding three-dimensional, high aspect ratio features to pre-existing PMMA micro molds for subsequent LIGA processing. This complimentary method involves in situ construction of three-dimensional micro molds in a stand-alone configuration or directly adjacent to features formed by x-ray lithography. Three-dimensional micro molds are created by micro stereolithography (MSL), an additive rapid prototyping technology. Alternatively, three-dimensional features may be added by direct femtosecond laser micro machining. Parameters for optimal femtosecond laser micro machining of PMMA at 800 nanometers are presented. The technical discussion also includes strategies for enhancements in the context of material selection and post-process surface finish. This approach may lead to practical, cost-effective 3-D MEMS with the surface finish and throughput advantages of x-ray lithography. Accurate three-dimensional metal microstructures are demonstrated. Challenges remain in process planning for micro stereolithography and development of buried features following femtosecond laser micro machining.

  12. Visual Interpretation with Three-Dimensional Annotations (VITA): Three-Dimensional Image Interpretation Tool for Radiological Reporting

    OpenAIRE

    Roy, Sharmili; Brown, Michael S.; Shih, George L.

    2013-01-01

    This paper introduces a software framework called Visual Interpretation with Three-Dimensional Annotations (VITA) that is able to automatically generate three-dimensional (3D) visual summaries based on radiological annotations made during routine exam reporting. VITA summaries are in the form of rotating 3D volumes where radiological annotations are highlighted to place important clinical observations into a 3D context. The rendered volume is produced as a Digital Imaging and Communications i...

  13. Electron tomography, three-dimensional Fourier analysis and colour prediction of a three-dimensional amorphous biophotonic nanostructure

    Science.gov (United States)

    Shawkey, Matthew D.; Saranathan, Vinodkumar; Pálsdóttir, Hildur; Crum, John; Ellisman, Mark H.; Auer, Manfred; Prum, Richard O.

    2009-01-01

    Organismal colour can be created by selective absorption of light by pigments or light scattering by photonic nanostructures. Photonic nanostructures may vary in refractive index over one, two or three dimensions and may be periodic over large spatial scales or amorphous with short-range order. Theoretical optical analysis of three-dimensional amorphous nanostructures has been challenging because these structures are difficult to describe accurately from conventional two-dimensional electron microscopy alone. Intermediate voltage electron microscopy (IVEM) with tomographic reconstruction adds three-dimensional data by using a high-power electron beam to penetrate and image sections of material sufficiently thick to contain a significant portion of the structure. Here, we use IVEM tomography to characterize a non-iridescent, three-dimensional biophotonic nanostructure: the spongy medullary layer from eastern bluebird Sialia sialis feather barbs. Tomography and three-dimensional Fourier analysis reveal that it is an amorphous, interconnected bicontinuous matrix that is appropriately ordered at local spatial scales in all three dimensions to coherently scatter light. The predicted reflectance spectra from the three-dimensional Fourier analysis are more precise than those predicted by previous two-dimensional Fourier analysis of transmission electron microscopy sections. These results highlight the usefulness, and obstacles, of tomography in the description and analysis of three-dimensional photonic structures. PMID:19158016

  14. MR-based three-dimensional presentation of cartilage thickness in the femoral head

    International Nuclear Information System (INIS)

    Nakanishi, Katsuyuki; Tanaka, Hisashi; Nakamura, Hironobu; Sato, Yoshinobu; Kubota, Tetsuya; Tamura, Shinichi; Ueguchi, Takashi

    2001-01-01

    The purpose of our study was to visualize the hyaline cartilage of the femoral head and to evaluate the distribution of the thickness by three-dimensional reconstruction of MRI data. The MRI was performed in 10 normal volunteers, 1 patient with osteonecrosis and 4 with advanced osteoarthritis. A fast 3D spoiled gradient-recalled acquisition in the steady state pulse sequence (TR 22 ms/TE 5.6 ms/no. of excitations 2) with fat suppression was used for data collection. Coronal and sagittal images were obtained with 3-mm effective slice thickness, 16-cm field of view (FOV) and 256 x 192 matrix. The MR images were reconstructed in three dimensions for evaluating the distribution of the cartilage thickness. In all normal volunteers, 1 patient with osteonecrosis and three advanced osteoarthritis, 3D reconstruction was successful, but in 1 case of osteoarthritis, 3D reconstruction failed because of the narrow joint space. In normal volunteers, the cartilage thickness is thickest in the central portion around the ligamentum teres (mean 2.8 mm). The medial portion and the lateral portion are almost of the same thickness (medial 1.3 mm, lateral 1.1 mm). In 3 cases of osteoarthritis, the cartilage became thinner in the lateral portions (<0.6 mm), but was unchanged in the central and medial portions. Three-dimensional reconstruction of MRI data is useful for evaluating the distribution of the cartilage thickness of the femoral head objectively. (orig.)

  15. MR-based three-dimensional presentation of cartilage thickness in the femoral head

    Energy Technology Data Exchange (ETDEWEB)

    Nakanishi, Katsuyuki [Dept. of Radiology, Osaka Seamen' s Insurance Hospital (Japan); Tanaka, Hisashi; Nakamura, Hironobu [Osaka Univ. (Japan). Dept. of Radiology; Sugano, Nobuhiko [Dept. of Orthopedic Surgery, Osaka University Medical School (Japan); Sato, Yoshinobu; Kubota, Tetsuya; Tamura, Shinichi [Div. of Functional Imaging, Osaka University Medical School (Japan); Ueguchi, Takashi [Dept. of Radiology, Osaka University Medical Hospital (Japan)

    2001-11-01

    The purpose of our study was to visualize the hyaline cartilage of the femoral head and to evaluate the distribution of the thickness by three-dimensional reconstruction of MRI data. The MRI was performed in 10 normal volunteers, 1 patient with osteonecrosis and 4 with advanced osteoarthritis. A fast 3D spoiled gradient-recalled acquisition in the steady state pulse sequence (TR 22 ms/TE 5.6 ms/no. of excitations 2) with fat suppression was used for data collection. Coronal and sagittal images were obtained with 3-mm effective slice thickness, 16-cm field of view (FOV) and 256 x 192 matrix. The MR images were reconstructed in three dimensions for evaluating the distribution of the cartilage thickness. In all normal volunteers, 1 patient with osteonecrosis and three advanced osteoarthritis, 3D reconstruction was successful, but in 1 case of osteoarthritis, 3D reconstruction failed because of the narrow joint space. In normal volunteers, the cartilage thickness is thickest in the central portion around the ligamentum teres (mean 2.8 mm). The medial portion and the lateral portion are almost of the same thickness (medial 1.3 mm, lateral 1.1 mm). In 3 cases of osteoarthritis, the cartilage became thinner in the lateral portions (<0.6 mm), but was unchanged in the central and medial portions. Three-dimensional reconstruction of MRI data is useful for evaluating the distribution of the cartilage thickness of the femoral head objectively. (orig.)

  16. Stereoscopic Three-Dimensional Visualization Applied to Multimodal Brain Images: Clinical Applications and a Functional Connectivity Atlas.

    Directory of Open Access Journals (Sweden)

    Gonzalo M Rojas

    2014-11-01

    Full Text Available Effective visualization is central to the exploration and comprehension of brain imaging data. While MRI data are acquired in three-dimensional space, the methods for visualizing such data have rarely taken advantage of three-dimensional stereoscopic technologies. We present here results of stereoscopic visualization of clinical data, as well as an atlas of whole-brain functional connectivity. In comparison with traditional 3D rendering techniques, we demonstrate the utility of stereoscopic visualizations to provide an intuitive description of the exact location and the relative sizes of various brain landmarks, structures and lesions. In the case of resting state fMRI, stereoscopic 3D visualization facilitated comprehension of the anatomical position of complex large-scale functional connectivity patterns. Overall, stereoscopic visualization improves the intuitive visual comprehension of image contents, and brings increased dimensionality to visualization of traditional MRI data, as well as patterns of functional connectivity.

  17. A plastic surgery application in evolution: three-dimensional printing.

    Science.gov (United States)

    Gerstle, Theodore L; Ibrahim, Ahmed M S; Kim, Peter S; Lee, Bernard T; Lin, Samuel J

    2014-02-01

    Three-dimensional printing represents an evolving technology still in its infancy. Currently, individuals and small business entities have the ability to manufacture physical objects from digital renderings, computer-aided design, and open source files. Design modifications and improvements in extrusion methods have made this technology much more affordable. This article explores the potential uses of three-dimensional printing in plastic surgery. A review was performed detailing the known uses of three-dimensional printing in medicine. The potential applications of three-dimensional printing in plastic surgery are discussed. Various applications for three-dimensional printing technology have emerged in medicine, including printing organs, printing body parts, bio-printing, and computer-aided tissue engineering. In plastic surgery, these tools offer various prospective applications for surgical planning, resident education, and the development of custom prosthetics. Numerous applications exist in medicine, including the printing of devices, implants, tissue replacements, and even whole organs. Plastic surgeons may likely find this technology indispensable in surgical planning, education, and prosthetic device design and development in the near future.

  18. Three-dimensional printing and pediatric liver disease.

    Science.gov (United States)

    Alkhouri, Naim; Zein, Nizar N

    2016-10-01

    Enthusiastic physicians and medical researchers are investigating the role of three-dimensional printing in medicine. The purpose of the current review is to provide a concise summary of the role of three-dimensional printing technology as it relates to the field of pediatric hepatology and liver transplantation. Our group and others have recently demonstrated the feasibility of printing three-dimensional livers with identical anatomical and geometrical landmarks to the native liver to facilitate presurgical planning of complex liver surgeries. Medical educators are exploring the use of three-dimensional printed organs in anatomy classes and surgical residencies. Moreover, mini-livers are being developed by regenerative medicine scientist as a way to test new drugs and, eventually, whole livers will be grown in the laboratory to replace organs with end-stage disease solving the organ shortage problem. From presurgical planning to medical education to ultimately the bioprinting of whole organs for transplantation, three-dimensional printing will change medicine as we know in the next few years.

  19. Three-dimensional imagery by encoding sources of X rays

    International Nuclear Information System (INIS)

    Magnin, Isabelle

    1987-01-01

    This research thesis addresses the theoretical and practical study of X ray coded sources, and thus notably aims at exploring whether it would be possible to transform a standard digital radiography apparatus (as those operated in radiology hospital departments) into a low cost three-dimensional imagery system. The author first recalls the principle of conventional tomography and improvement attempts, and describes imagery techniques based on the use of encoding openings and source encoding. She reports the modelling of an imagery system based on encoded sources of X ray, and addresses the original notion of three-dimensional response for such a system. The author then addresses the reconstruction method by considering the reconstruction of a plane object, of a multi-plane object, and of real three-dimensional object. The frequency properties and the tomographic capacities of various types of source codes are analysed. She describes a prototype tomography apparatus, and presents and discusses three-dimensional actual phantom reconstructions. She finally introduces a new principle of dynamic three-dimensional radiography which implements an acquisition technique by 'gating code'. The acquisition principle should allow the reconstruction of volumes animated by periodic deformations, such as the heart for example [fr

  20. Three-dimensional MR imaging in the assessment of physeal growth arrest.

    Science.gov (United States)

    Sailhan, Frédéric; Chotel, Franck; Guibal, Anne-Laure; Gollogly, Sohrab; Adam, Philippe; Bérard, Jérome; Guibaud, Laurent

    2004-09-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  1. Three-dimensional MR imaging in the assessment of physeal growth arrest

    Energy Technology Data Exchange (ETDEWEB)

    Sailhan, Frederic; Chotel, Franck; Gollogly, Sohrab; Adam, Philippe; Berard, Jerome [Department of Orthopaedics, Hopital Bebrousse, 29 rue Soeur Bouvier, 69005, Lyon (France); Guibal, Anne-Laure; Guibaud, Laurent [Department of Radiology, Hopital Bebrousse, 29 rue Soeur Bouvier, 69005, Lyon (France)

    2004-09-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  2. Three-dimensional MR imaging in the assessment of physeal growth arrest

    International Nuclear Information System (INIS)

    Sailhan, Frederic; Chotel, Franck; Gollogly, Sohrab; Adam, Philippe; Berard, Jerome; Guibal, Anne-Laure; Guibaud, Laurent

    2004-01-01

    The purpose of this study is to describe an imaging method for identifying and characterising physeal growth arrest following physeal plate aggression. The authors describe the use of three-dimensional MRI performed with fat-suppressed three-dimensional spoiled gradient-recalled echo sequences followed by manual image reconstruction to create a 3D model of the physeal plate. This retrospective series reports the analysis of 33 bony physeal bridges in 28 children (mean age 10.5 years) with the use of fat-suppressed three-dimensional spoiled gradient-recalled echo imaging and 3D reconstructions from the source images. 3D reconstructions were obtained after the outlining was done manually on each source image. Files of all patients were reviewed for clinical data at the time of MRI, type of injury, age at MRI and bone bridge characteristics on reconstructions. Twenty-one (63%) of the 33 bridges were post-traumatic and were mostly situated in the lower extremities (19/21). The distal tibia was involved in 66% (14/21) of the cases. Bridges due to causes other than trauma were located in the lower extremities in 10/12 cases, and the distal femur represented 60% of these cases. Of the 28 patients, five presented with two bridges involving two different growth plates making a total of 33 physeal bone bars. The location and shape of each bridge was accurately identified in each patient, and in post-traumatic cases, 89% of bone bars were of Ogden type III (central) or I (peripheral). Reconstructions were obtained in 15 min and are easy to interpret. Volumes of the physeal bone bridge(s) and of the remaining normal physis were calculated. The bone bridging represented less than 1% to 47% of the total physeal plate volume. The precise shape and location of the bridge can be visualised on the 3D reconstructions. This information is useful in the surgical management of these deformities; as for the eight patients who underwent bone bar resection, an excellent correspondence was

  3. Three-dimensional particle image velocimetry measurement technique

    International Nuclear Information System (INIS)

    Hassan, Y.A.; Seeley, C.H.; Henderson, J.A.; Schmidl, W.D.

    2004-01-01

    The experimental flow visualization tool, Particle Image Velocimetry (PIV), is being used to determine the velocity field in two-dimensional fluid flows. In the past few years, the technique has been improved to allow the capture of flow fields in three dimensions. This paper describes changes which were made to two existing two-dimensional tracking algorithms to enable them to track three-dimensional PIV data. Results of the tests performed on these three-dimensional routines with synthetic data are presented. Experimental data was also used to test the tracking algorithms. The test setup which was used to acquire the three-dimensional experimental data is described, along with the results from both of the tracking routines which were used to analyze the experimental data. (author)

  4. Three-dimensional simulations of resistance spot welding

    DEFF Research Database (Denmark)

    Nielsen, Chris Valentin; Zhang, Wenqi; Perret, William

    2014-01-01

    This paper draws from the fundamentals of electro-thermo-mechanical coupling to the main aspects of finite element implementation and three-dimensional modelling of resistance welding. A new simulation environment is proposed in order to perform three-dimensional simulations and optimization...... of resistance welding together with the simulations of conventional and special-purpose quasi-static mechanical tests. Three-dimensional simulations of resistance welding consider the electrical, thermal, mechanical and metallurgical characteristics of the material as well as the operating conditions...... of the welding machines. Simulations of the mechanical tests take into account material softening due to the accumulation of ductile damage and cover conventional tests, such as tensile–shear tests, cross-tension test and peel tests, as well as the possibility of special-purpose tests designed by the users...

  5. Application of three-dimensional CT reconstruction cranioplasty

    International Nuclear Information System (INIS)

    Yan Shuli; Yun Yongxing; Wan Kunming; Qiu Jian

    2011-01-01

    Objective: To study the application of three-dimensional CT reconstruction in cranioplasty. Methods: 46 patients with skull defect were divided into two group. One group underwent CT examination and three-dimensional reconstruction, and then the Titanium nets production company manufactured corresponding titanium meshes were shaped those data before the operation. The other group received traditional operation in which titanium meshes were shaped during operation. The average time of operation were compared. Results: The average time of operation of the first group is 86.6±13.6 mins, and that of the second group is 115±15.0 mins. The difference of average operation time between the two groups was statistically significant. Conclusion: Three-dimensional CT reconstruction techniques contribute to shorten the average operation time, reduce the intensity of neurosurgeon's work and the patien's risk. (authors)

  6. Eustachian tube three-dimensional reconstruction of secretory otitis media

    International Nuclear Information System (INIS)

    Yu Yafeng; Zhou Weirong; Bao Xueping; Li Min; Hu Zhenmin

    2006-01-01

    Objective: To study relationship between Eustachian tube and secretory otitis media and to explore the pathogeny of secretory otitis by three-dimensional reconstruction of Eustachian tube. Methods: Thirty cases of secretory otitis media (male 19, female 11) were selected randomly. Everyone was checked by otoscope and audiometry. Their bilateral Eustachian tubes were scanning by helix CT while making Valsalva's action. All images were passed on to work station to make three-dimensional reconstruction. Results: Four patients were found have Eustachian tube diseases, while most of patients' Eustachian tubes ventilated normally. Conclusions: Three-dimensional reconstruction of Eustachian tube can open out some pathogens of some secretory otitis medias. It will be helpful to diagnosis and therapy of secretory otitis media. (authors)

  7. Three-dimensional CT of the pediatric spine

    International Nuclear Information System (INIS)

    Starshak, R.J.; Crawford, C.R.; Waisman, R.C.; Sty, J.R.

    1987-01-01

    CT of the spine has been shown to be useful in evaluating congenital, neoplastic, inflammatory, and traumatic lesions. Any portion of the neural arch may be involved by these disease processes. However, the complex nature of the spinal column can make evaluation of these abnormalities difficult on axial CT. This is especially true if the spine is distorted by scoliosis, kyphosis, or lordosis. The principal advantage of three-dimensional CT is its ability to display the surface relationships of complicated objects. The complexity of the spinal axis makes it ideal for study with three-dimensional CT. This presentation illustrates the advantages and drawbacks of three-dimensional CT in spinal abnormalities in children

  8. Two- and three-dimensional CT analysis of ankle fractures

    International Nuclear Information System (INIS)

    Magid, D.; Fishman, E.K.; Ney, D.R.; Kuhlman, J.E.

    1988-01-01

    CT with coronal and sagittal reformatting (two-dimensional CT) and animated volumetric image rendering (three-dimensional CT) was used to assess ankle fractures. Partial volume limits transaxial CT in assessments of horizontally oriented structures. Two-dimensional CT, being orthogonal to the plafond, superior mortise, talar dome, and tibial epiphysis, often provides the most clinically useful images. Two-dimensional CT is most useful in characterizing potentially confusing fractures, such as Tillaux (anterior tubercle), triplane, osteochondral talar dome, or nondisplaced talar neck fractures, and it is the best study to confirm intraarticular fragments. Two-and three-dimensional CT best indicate the percentage of articular surface involvement and best demonstrate postoperative results or complications (hardware migration, residual step-off, delayed union, DJD, AVN, etc). Animated three-dimensional images are the preferred means of integrating the two-dimensional findings for surgical planning, as these images more closely simulate the clinical problem

  9. Prognostic value of three-dimensional ultrasound for fetal hydronephrosis

    Science.gov (United States)

    WANG, JUNMEI; YING, WEIWEN; TANG, DAXING; YANG, LIMING; LIU, DONGSHENG; LIU, YUANHUI; PAN, JIAOE; XIE, XING

    2015-01-01

    The present study evaluated the prognostic value of three-dimensional ultrasound for fetal hydronephrosis. Pregnant females with fetal hydronephrosis were enrolled and a novel three-dimensional ultrasound indicator, renal parenchymal volume/kidney volume, was introduced to predict the postnatal prognosis of fetal hydronephrosis in comparison with commonly used ultrasound indicators. All ultrasound indicators of fetal hydronephrosis could predict whether postnatal surgery was required for fetal hydronephrosis; however, the predictive performance of renal parenchymal volume/kidney volume measurements as an individual indicator was the highest. In conclusion, ultrasound is important in predicting whether postnatal surgery is required for fetal hydronephrosis, and the three-dimensional ultrasound indicator renal parenchymal volume/kidney volume has a high predictive performance. Furthermore, the majority of cases of fetal hydronephrosis spontaneously regress subsequent to birth, and the regression time is closely associated with ultrasound indicators. PMID:25667626

  10. A method of image improvement in three-dimensional imaging

    International Nuclear Information System (INIS)

    Suto, Yasuzo; Huang, Tewen; Furuhata, Kentaro; Uchino, Masafumi.

    1988-01-01

    In general, image interpolation is required when the surface configurations of such structures as bones and organs are three-dimensionally constructed from the multi-sliced images obtained by CT. Image interpolation is a processing method whereby an artificial image is inserted between two adjacent slices to make spatial resolution equal to slice resolution in appearance. Such image interpolation makes it possible to increase the image quality of the constructed three-dimensional image. In our newly-developed algorithm, we have converted the presently and subsequently sliced images to distance images, and generated the interpolation images from these two distance images. As a result, compared with the previous method, three-dimensional images with better image quality have been constructed. (author)

  11. Three-dimensional, three-component wall-PIV

    Science.gov (United States)

    Berthe, André; Kondermann, Daniel; Christensen, Carolyn; Goubergrits, Leonid; Garbe, Christoph; Affeld, Klaus; Kertzscher, Ulrich

    2010-06-01

    This paper describes a new time-resolved three-dimensional, three-component (3D-3C) measurement technique called wall-PIV. It was developed to assess near wall flow fields and shear rates near non-planar surfaces. The method is based on light absorption according to Beer-Lambert’s law. The fluid containing a molecular dye and seeded with buoyant particles is illuminated by a monochromatic, diffuse light. Due to the dye, the depth of view is limited to the near wall layer. The three-dimensional particle positions can be reconstructed by the intensities of the particle’s projection on an image sensor. The flow estimation is performed by a new algorithm, based on learned particle trajectories. Possible sources of measurement errors related to the wall-PIV technique are analyzed. The accuracy analysis was based on single particle experiments and a three-dimensional artificial data set simulating a rotating sphere.

  12. A three-dimensional field solutions of Halbach

    International Nuclear Information System (INIS)

    Chen Jizhong; Xiao Jijun; Zhang Yiming; Xu Chunyan

    2008-01-01

    A three-dimensional field solutions are presented for Halback cylinder magnet. Based on Ampere equivalent current methods, the permanent magnets are taken as distributing of current density. For getting the three-dimensional field solution of ideal polarized permanent magnets, the solution method entails the use of the vector potential and involves the closed-form integration of the free-space Green's function. The programmed field solution are ideal for performing rapid parametric studies of the dipole Halback cylinder magnets made from rare earth materials. The field solutions are verified by both an analytical two-dimensional algorithm and three-dimensional finite element software. A rapid method is presented for extensive analyzing and optimizing Halbach cylinder magnet. (authors)

  13. Computational methods for three-dimensional microscopy reconstruction

    CERN Document Server

    Frank, Joachim

    2014-01-01

    Approaches to the recovery of three-dimensional information on a biological object, which are often formulated or implemented initially in an intuitive way, are concisely described here based on physical models of the object and the image-formation process. Both three-dimensional electron microscopy and X-ray tomography can be captured in the same mathematical framework, leading to closely-related computational approaches, but the methodologies differ in detail and hence pose different challenges. The editors of this volume, Gabor T. Herman and Joachim Frank, are experts in the respective methodologies and present research at the forefront of biological imaging and structural biology.   Computational Methods for Three-Dimensional Microscopy Reconstruction will serve as a useful resource for scholars interested in the development of computational methods for structural biology and cell biology, particularly in the area of 3D imaging and modeling.

  14. Three-dimensional CT imaging of soft-tissue anatomy

    International Nuclear Information System (INIS)

    Fishman, E.K.; Ney, D.R.; Magid, D.; Kuhlman, J.E.

    1988-01-01

    Three-dimensional display of computed tomographic data has been limited to skeletal structures. This was in part related to the reconstruction algorithm used, which relied on a binary classification scheme. A new algorithm, volumetric rendering with percentage classification, provides the ability to display three-dimensional images of muscle and soft tissue. A review was conducted of images in 35 cases in which muscle and/or soft tissue were part of the clinical problem. In all cases, individual muscle groups could be clearly identified and discriminated. Branching vessels in the range of 2.3 mm could be identified. Similarly, lymph nodes could be clearly defined. High-resolution three-dimensional images were found to be useful both in providing an increased understanding of complex muscle and soft tissue anatomy and in surgical planning

  15. Extending generalized Kubelka-Munk to three-dimensional radiative transfer.

    Science.gov (United States)

    Sandoval, Christopher; Kim, Arnold D

    2015-08-10

    The generalized Kubelka-Munk (gKM) approximation is a linear transformation of the double spherical harmonics of order one (DP1) approximation of the radiative transfer equation. Here, we extend the gKM approximation to study problems in three-dimensional radiative transfer. In particular, we derive the gKM approximation for the problem of collimated beam propagation and scattering in a plane-parallel slab composed of a uniform absorbing and scattering medium. The result is an 8×8 system of partial differential equations that is much easier to solve than the radiative transfer equation. We compare the solutions of the gKM approximation with Monte Carlo simulations of the radiative transfer equation to identify the range of validity for this approximation. We find that the gKM approximation is accurate for isotropic scattering media that are sufficiently thick and much less accurate for anisotropic, forward-peaked scattering media.

  16. Development and anisotropy of three-dimensional turbulence in a current sheet

    International Nuclear Information System (INIS)

    Onofri, M.; Veltri, P.; Malara, F.

    2007-01-01

    The nonlinear evolution of three-dimensional reconnection instabilities are studied in a current sheet where many resonant surfaces are simultaneously present at different locations of the simulation domain. The nonlinear evolution produces the development of anisotropic magnetohydrodynamic turbulence. The development of the energy spectrum is followed until the energy is transported to the dissipative length scale and the anisotropy of the spectrum is analyzed. The energy cascade is affected by the Alfven effect and it takes place mainly in the direction perpendicular to the local average magnetic field. Anisotropy is also affected by propagation of perturbations across the main magnetic field, due to the growth of a transverse component related to reconnection. The direction of anisotropy varies with the position in space. The spectral index is different both from what is found in homogeneous isotropic turbulence and from the values predicted for magnetohydrodynamic turbulence with a uniform large-scale magnetic field

  17. Transmission probability method for solving neutron transport equation in three-dimensional triangular-z geometry

    Energy Technology Data Exchange (ETDEWEB)

    Liu Guoming [Department of Nuclear Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)], E-mail: gmliusy@gmail.com; Wu Hongchun; Cao Liangzhi [Department of Nuclear Engineering, Xi' an Jiaotong University, Xi' an, Shaanxi 710049 (China)

    2008-09-15

    This paper presents a transmission probability method (TPM) to solve the neutron transport equation in three-dimensional triangular-z geometry. The source within the mesh is assumed to be spatially uniform and isotropic. At the mesh surface, the constant and the simplified P{sub 1} approximation are invoked for the anisotropic angular flux distribution. Based on this model, a code TPMTDT is encoded. It was verified by three 3D Takeda benchmark problems, in which the first two problems are in XYZ geometry and the last one is in hexagonal-z geometry, and an unstructured geometry problem. The results of the present method agree well with those of Monte-Carlo calculation method and Spherical Harmonics (P{sub N}) method.

  18. Three-dimensional simulation of diamagnetic cavity formation by a finite-sized plasma beam

    International Nuclear Information System (INIS)

    Thomas, V.A.

    1989-01-01

    The problem of collisionless coupling between a plasma beam and a background plasma is examined using a three-dimensional hybrid code. The beam is assumed to be moving parallel to an ambient magnetic field at a speed greater than the local Alfven speed. In addition, the beam has a finite spatial extent in the directions perpendicular to the magnetic field and is uniform and infinite in the direction parallel to the ambient magnetic field. Such a system is susceptible to coupling of the beam ions with the background ions via an electromagnetic ion beam instability. This instability isotropizes the beam and energizes the background plasma. A large-amplitude Alfven wave traveling radially away from the interaction region is associated with the energized background plasma. The process described here is one which may be responsible for the formation of diamagnetic cavities observed in the solar wind. copyright American Geophysical Union 1989

  19. Soft-tissue segmentation and three-dimensional display with MR imaging

    International Nuclear Information System (INIS)

    Koenig, H.A.; Laub, G.

    1987-01-01

    The purpose of this study is to design a method capable of segmenting different soft-tissue types. The investigated cases were measured using fast three-dimensional (3D) sequences (FISP of fast low-angle shot) with isotropic voxel resolution of nearly 1 mm. The segmentation is based on the assumption that different tissue types are discernible by their morphologic and/or physical features. Surface reconstructions are then used to display specific tissue types from different viewing directions. This automatic procedure is applied to different head cases to represent specific tissues in 3D format. With 3D techniques, rotation of classified objects in cine format is performed for better topologic correlation and therapeutic planning

  20. Three-dimensional quadrupole lenses made with permanent magnets

    International Nuclear Information System (INIS)

    Ivanov, A.S.

    1984-01-01

    The performance of accelerator systems with quadrupole magnets can be improved by using permanent magnets in quadrupole lenses. This requires better methods for treating the three-dimensional nature of the magnetic fields and the nonlinear characteristics of the magnets. A numerical method is described for simulating three-dimensional magnetic fields and used to analyze quadrupole lenses and doublets with permanent magnets. The results, which are confirmed experimentally, indicate that both the quadrupole magnetic gradient and the effective field length are changed in permanent-magnet quadrupole lenses when the pole lengths and the gap between the lenses are varied while the other characteristics of the magnets remain unchanged

  1. Three dimensional imaging technique for laser-plasma diagnostics

    International Nuclear Information System (INIS)

    Jiang Shaoen; Zheng Zhijian; Liu Zhongli

    2001-01-01

    A CT technique for laser-plasma diagnostic and a three-dimensional (3D) image reconstruction program (CT3D) have been developed. The 3D images of the laser-plasma are reconstructed by using a multiplication algebraic reconstruction technique (MART) from five pinhole camera images obtained along different sight directions. The technique has been used to measure the three-dimensional distribution of X-ray of laser-plasma experiments in Xingguang II device, and the good results are obtained. This shows that a CT technique can be applied to ICF experiments

  2. Three-dimensional flow and turbulence structure in electrostatic precipitator

    DEFF Research Database (Denmark)

    Ullum, Thorvald Uhrskov; Larsen, Poul Scheel; Özcan, Oktay

    2002-01-01

    Stereo PIV is employed to study the three-dimensional velocity and turbulence fields in a laboratory model of a negative corona, barbed-wire, smooth-plate, electrostatic precipitator (figure 1). The study is focused on determining the parametric effects of axial development, mean current density Jm...... and bulk velocity U0 on secondary flows and turbulence levels and structures due to the action of the three-dimensional electrostatic field on the charged gas. At constant bulk velocity (U0 = 1 m/s) and current density (Jm = 0.4 mA/m2), secondary flows in the form of rolls of axial vorticity with swirl...

  3. Three-dimensional wax patterning of paper fluidic devices.

    Science.gov (United States)

    Renault, Christophe; Koehne, Jessica; Ricco, Antonio J; Crooks, Richard M

    2014-06-17

    In this paper we describe a method for three-dimensional wax patterning of microfluidic paper-based analytical devices (μPADs). The method is rooted in the fundamental details of wax transport in paper and provides a simple way to fabricate complex channel architectures such as hemichannels and fully enclosed channels. We show that three-dimensional μPADs can be fabricated with half as much paper by using hemichannels rather than ordinary open channels. We also provide evidence that fully enclosed channels are efficiently isolated from the exterior environment, decreasing contamination risks, simplifying the handling of the device, and slowing evaporation of solvents.

  4. Three dimensional investigation of oceanic active faults. A demonstration survey

    Energy Technology Data Exchange (ETDEWEB)

    Nakao, Seizo; Kishimoto, Kiyoyuki; Kuramoto, Shinichi; Sato, Mikio [Geological Survey of Japan, Tsukuba, Ibaraki (Japan)

    1998-02-01

    In order to upgrade probability of activity and action potential evaluation of oceanic active faults which have some important effects on nuclear facilities, trench type oceanic active fault was investigated three dimensionally. Contents of the investigation were high precision sea bottom topographic survey and sea bottom back scattering wave image data observation by using a sea bottom topography acoustic imaginator. And, by high resolution earthquake wave survey, high precision survey of an active fault under sea bottom was conducted to detect oceanic active faults three-dimensionally. Furthermore, the generally issued data were summarized to promote to construct a data base for evaluating the active faults. (G.K.)

  5. Implementation of three dimensional treatment planning system for external radiotherapy

    International Nuclear Information System (INIS)

    Major, Tibor; Kurup, P.G.G.; Stumpf, Janos

    1997-01-01

    A three dimensional (3D) treatment planning system was installed at Apollo Cancer Hospital, Chennai, India in 1995. This paper gives a short description of the system including hardware components, calculation algorithm, measured data requirements and specific three dimensional features. The concept and the structure of the system are shortly described. The first impressions along with critical opinions and the experiences are gained during the data acquisition are mentioned. Some improvements in the user interface are suggested. It is emphasized that although a 3D system offers more detailed and accurate dose distributions compared to a 2D system, it also introduces a greatly increased workload for the planning staff. (author)

  6. Resonance fluorescence based two- and three-dimensional atom localization

    Science.gov (United States)

    Wahab, Abdul; Rahmatullah; Qamar, Sajid

    2016-06-01

    Two- and three-dimensional atom localization in a two-level atom-field system via resonance fluorescence is suggested. For the two-dimensional localization, the atom interacts with two orthogonal standing-wave fields, whereas for the three-dimensional atom localization, the atom interacts with three orthogonal standing-wave fields. The effect of the detuning and phase shifts associated with the corresponding standing-wave fields is investigated. A precision enhancement in position measurement of the single atom can be noticed via the control of the detuning and phase shifts.

  7. Three dimensional imaging technique for laser-plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Shaoen, Jiang; Zhijian, Zheng; Zhongli, Liu [China Academy of Engineering Physics, Chengdu (China)

    2001-04-01

    A CT technique for laser-plasma diagnostic and a three-dimensional (3D) image reconstruction program (CT3D) have been developed. The 3D images of the laser-plasma are reconstructed by using a multiplication algebraic reconstruction technique (MART) from five pinhole camera images obtained along different sight directions. The technique has been used to measure the three-dimensional distribution of X-ray of laser-plasma experiments in Xingguang II device, and the good results are obtained. This shows that a CT technique can be applied to ICF experiments.

  8. Three dimensional investigation of oceanic active faults. A demonstration survey

    International Nuclear Information System (INIS)

    Nakao, Seizo; Kishimoto, Kiyoyuki; Kuramoto, Shinichi; Sato, Mikio

    1998-01-01

    In order to upgrade probability of activity and action potential evaluation of oceanic active faults which have some important effects on nuclear facilities, trench type oceanic active fault was investigated three dimensionally. Contents of the investigation were high precision sea bottom topographic survey and sea bottom back scattering wave image data observation by using a sea bottom topography acoustic imaginator. And, by high resolution earthquake wave survey, high precision survey of an active fault under sea bottom was conducted to detect oceanic active faults three-dimensionally. Furthermore, the generally issued data were summarized to promote to construct a data base for evaluating the active faults. (G.K.)

  9. Three-dimensional Reciprocal Structures: Morphology, Concepts, Generative Rules

    DEFF Research Database (Denmark)

    Parigi, Dario; Pugnale, Alberto

    2012-01-01

    , causing every configuration to develop naturally out-of the plane. The structures presented here were developed and built by the students of the Master of Science in “Architectural Design” during a two week long workshop organized at Aalborg University in the fall semester 2011.......This paper present seven different three dimensional structures based on the principle of structural reciprocity with superimposition joint and standardized un-notched elements. Such typology could be regarded as being intrinsically three-dimensional because elements sit one of the top of the other...

  10. Virtual reality publication of spiral ct-derived three-dimensional models: or, creation of spiral, CT-derived, three-dimensional VRML objects.

    Science.gov (United States)

    Tyszka, J M

    1997-01-01

    Three-dimensional models can be generated from slice images, such as those obtained from computed tomography (CT) and magnetic resonance imaging (MRI) using a variety of techniques. A popular method for rendering 3D anatomical models is the creation of polygonal mesh surfaces representing the boundary between tissues. Mesh surfaces can be rendered extremely quickly using conventional personal computers, without recourse to more expensive graphic workstations. The dissemination of three-dimensional (3D) models across the Internet has been made significantly easier by the definition of the Virtual Reality Markup Language (VRML) format. The VRML definition allows the parameters and relationships of 3D objects to be described in a text format. The text file can be transfered from a host computer to a remote client computer through the World Wide Web and viewed using readily available software (See Appendix). VRML is based on the definition of primitive 3D objects such as polygons and spheres. Consequently, the transition from a mesh surface derived from a clinical image data set to a VRML object is relatively simple, allowing for convenient and cost-effective dissemination of 3D clinical models across the internet.

  11. Stability analysis of non-axisymmetric three-dimensional finite ...

    Indian Academy of Sciences (India)

    The present work explores the use of mass-lumping in stability ... further considers orthotropic flexible support which makes the stiffness matrix a ... symmetric rotor on rigid, isotropic and orthotropic bearing is stable in absence of a destabilizing.

  12. Diffusion tensor imaging and three-dimensional brain fiber tracking for the diagnosis of multiple sclerosis

    Energy Technology Data Exchange (ETDEWEB)

    Bing, Hu; Hong, Shan; Mingyue, Luo; Shaoqiong, Chen; Wang, Kang; Bingjun, He; Yan, Zou [Department of Radiology, the 3rd Affiliated Hospital of Sun Yat-sen Univ., Guangzhou (China); Binbin, Ye

    2007-02-15

    Objective: To demonstrate the diffusion tensor imaging (DTI) characteristics of multiple sclerosis (MS) plaques, periplaque white matter regions and normal appearing white matter (NAWM) regions in patients with MS, and to evaluate the clinical values of DTI and three-dimensional brain fiber tracking for the diagnosis of MS. Methods: Conventional MRI and DTI were performed in 32 patients with MS and 32 age-matched control subjects. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps were generated and coregistered with T{sub 2}-weighted MR images. FA and ADC values were calculated in regions of interest in plaques, periplaque white matter regions, NAWM regions and white matter regions in control subjects. And three-dimensional brain fiber tracking maps were generated by using the DTI. Results: The ADC was (1.233 {+-} 0.119) x 10{sup -3} mm{sup 2}/s in MS plaques, (0.973 {+-} 0.098) x 10{sup -3} mm{sup 2}/s in periplaque white matter regions, (0.748 {+-} 0.089) x 10{sup -3} mm{sup 2}/s in NAWM, and (0.620 {+-} 0.094) x 10{sup -3} mm{sup 2}/s in control subjects. The FA was 0.225 {+-} 0.052 in MS plaques, 0.311 {+-} 0.050 in periplaque white matter regions, 0.421 {+-} 0.070 in NAWM, and 0.476 {+-} 0.069 in control subjects. Significant differences in FA and ADC values were observed among all white matter regions (P<0.01). MS plaques were demonstrated in three-dimensional brain fiber tracking maps. Conclusion: FA and ADC maps are helpful for the evaluation of all white matter changes of MS. The abnormalities of white matter fiber tracts in MS plaques could be demonstrated in three-dimensional brain fiber tracking maps. (authors)

  13. Diffusion tensor imaging and three-dimensional brain fiber tracking for the diagnosis of multiple sclerosis

    International Nuclear Information System (INIS)

    Hu Bing; Shan Hong; Luo Mingyue; Chen Shaoqiong; Kang Wang; He Bingjun; Zou Yan; Ye Binbin

    2007-01-01

    Objective: To demonstrate the diffusion tensor imaging (DTI) characteristics of multiple sclerosis (MS) plaques, periplaque white matter regions and normal appearing white matter (NAWM) regions in patients with MS, and to evaluate the clinical values of DTI and three-dimensional brain fiber tracking for the diagnosis of MS. Methods: Conventional MRI and DTI were performed in 32 patients with MS and 32 age-matched control subjects. Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) maps were generated and coregistered with T 2 -weighted MR images. FA and ADC values were calculated in regions of interest in plaques, periplaque white matter regions, NAWM regions and white matter regions in control subjects. And three-dimensional brain fiber tracking maps were generated by using the DTI. Results: The ADC was (1.233 ± 0.119) x 10 -3 mm 2 /s in MS plaques, (0.973 ± 0.098) x 10 -3 mm 2 /s in periplaque white matter regions, (0.748 ± 0.089) x 10 -3 mm 2 /s in NAWM, and (0.620 ± 0.094) x 10 -3 mm 2 /s in control subjects. The FA was 0.225 ± 0.052 in MS plaques, 0.311 ± 0.050 in periplaque white matter regions, 0.421 ± 0.070 in NAWM, and 0.476 ± 0.069 in control subjects. Significant differences in FA and ADC values were observed among all white matter regions (P<0.01). MS plaques were demonstrated in three-dimensional brain fiber tracking maps. Conclusion: FA and ADC maps are helpful for the evaluation of all white matter changes of MS. The abnormalities of white matter fiber tracts in MS plaques could be demonstrated in three-dimensional brain fiber tracking maps. (authors)

  14. Acid-base properties of complexes with three-dimensional polyligands. Complexes with three-dimensional polyphosphoric acids

    International Nuclear Information System (INIS)

    Kopylova, V.D.; Bojko, Eh.T.; Saldadze, K.M.

    1985-01-01

    By the method of potentiometric titration acid-base properties of uranyl (2) complexes with three-dimensional polyphosphoric acids, KRF-8p, KF-1, KF-7 prepared by phosphorylation of copolymer of styrene and divinylbenzene or saponification of the copolymers of di-2,2'-chloroethyl ester of vinylphosphonic acid with divinyl benzene are studied. It is shown that in case of formation in the phase of three-dimensional polyphosphoric acids of UO 2 2+ complexes with the growth of bond covalence of metal ion-phosphonic group the acidjty of the second hydroxyl of the phosphonic group increases

  15. Three Dimensional Polarimetric Neutron Tomography of Magnetic Fields

    DEFF Research Database (Denmark)

    Sales, Morten; Strobl, Markus; Shinohara, Takenao

    2018-01-01

    Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non-destructively wi......Through the use of Time-of-Flight Three Dimensional Polarimetric Neutron Tomography (ToF 3DPNT) we have for the first time successfully demonstrated a technique capable of measuring and reconstructing three dimensional magnetic field strengths and directions unobtrusively and non...... and reconstructed, thereby providing the proof-of-principle of a technique able to reveal hitherto unobtainable information on the magnetic fields in the bulk of materials and devices, due to a high degree of penetration into many materials, including metals, and the sensitivity of neutron polarisation to magnetic...... fields. The technique puts the potential of the ToF time structure of pulsed neutron sources to full use in order to optimise the recorded information quality and reduce measurement time....

  16. Three-Dimensional Extension of a Digital Library Service System

    Science.gov (United States)

    Xiao, Long

    2010-01-01

    Purpose: The paper aims to provide an overall methodology and case study for the innovation and extension of a digital library, especially the service system. Design/methodology/approach: Based on the three-dimensional structure theory of the information service industry, this paper combines a comprehensive analysis with the practical experiences…

  17. Quantum field between moving mirrors: A three dimensional example

    Science.gov (United States)

    Hacyan, S.; Jauregui, Roco; Villarreal, Carlos

    1995-01-01

    The scalar quantum field uniformly moving plates in three dimensional space is studied. Field equations for Dirichlet boundary conditions are solved exactly. Comparison of the resulting wavefunctions with their instantaneous static counterpart is performed via Bogolubov coefficients. Unlike the one dimensional problem, 'particle' creation as well as squeezing may occur. The time dependent Casimir energy is also evaluated.

  18. Three-dimensional fractal geometry for gas permeation in microchannels

    NARCIS (Netherlands)

    Malankowska, Magdalena; Schlautmann, Stefan; Berenschot, Erwin J.W.; Tiggelaar, Roald M.; Pina, Maria Pilar; Mallada, Reyes; Tas, Niels R.; Gardeniers, Han

    2018-01-01

    The novel concept of a microfluidic chip with an integrated three-dimensional fractal geometry with nanopores, acting as a gas transport membrane, is presented. The method of engineering the 3D fractal structure is based on a combination of anisotropic etching of silicon and corner lithography. The

  19. A DETERMINISTIC METHOD FOR TRANSIENT, THREE-DIMENSIONAL NUETRON TRANSPORT

    International Nuclear Information System (INIS)

    S. GOLUOGLU, C. BENTLEY, R. DEMEGLIO, M. DUNN, K. NORTON, R. PEVEY I.SUSLOV AND H.L. DODDS

    1998-01-01

    A deterministic method for solving the time-dependent, three-dimensional Boltzmam transport equation with explicit representation of delayed neutrons has been developed and evaluated. The methodology used in this study for the time variable of the neutron flux is known as the improved quasi-static (IQS) method. The position, energy, and angle-dependent neutron flux is computed deterministically by using the three-dimensional discrete ordinates code TORT. This paper briefly describes the methodology and selected results. The code developed at the University of Tennessee based on this methodology is called TDTORT. TDTORT can be used to model transients involving voided and/or strongly absorbing regions that require transport theory for accuracy. This code can also be used to model either small high-leakage systems, such as space reactors, or asymmetric control rod movements. TDTORT can model step, ramp, step followed by another step, and step followed by ramp type perturbations. It can also model columnwise rod movement can also be modeled. A special case of columnwise rod movement in a three-dimensional model of a boiling water reactor (BWR) with simple adiabatic feedback is also included. TDTORT is verified through several transient one-dimensional, two-dimensional, and three-dimensional benchmark problems. The results show that the transport methodology and corresponding code developed in this work have sufficient accuracy and speed for computing the dynamic behavior of complex multidimensional neutronic systems

  20. Scattering and conductance quantization in three-dimensional metal nanocontacts

    DEFF Research Database (Denmark)

    Brandbyge, Mads; Jacobsen, Karsten Wedel; Nørskov, Jens Kehlet

    1997-01-01

    The transmission through three-dimensional nanocontacts is calculated in the presence of localized scattering centers and boundary scattering using a coupled-channel recursion method. Simple confining potentials are used to investigate how robust the observation of quantized conductance is with r...

  1. Three-dimensional reconstruction of the pigeon inner ear

    NARCIS (Netherlands)

    Hofman, R.; Segenhout, J. M.; Wit, H. P.

    2009-01-01

    Three-dimensional reconstructions of the inner ear of the pigeon (Columba livia domestica), from two-dimensional images, obtained with (conventional) light microscopy or orthogonal-plane fluorescence optical sectioning (OPFOS), are presented. The results are compared with available information on

  2. A note on the three dimensional sine--Gordon equation

    OpenAIRE

    Shariati, Ahmad

    1996-01-01

    Using a simple ansatz for the solutions of the three dimensional generalization of the sine--Gordon and Toda model introduced by Konopelchenko and Rogers, a class of solutions is found by elementary methods. It is also shown that these equations are not evolution equations in the sense that solution to the initial value problem is not unique.

  3. Three-dimensional reacting shock–bubble interaction

    NARCIS (Netherlands)

    Diegelmann, Felix; Hickel, S.; Adams, Nikolaus A.

    2017-01-01

    We investigate a reacting shock–bubble interaction through three-dimensional numerical simulations with detailed chemistry. The convex shape of the bubble focuses the shock and generates regions of high pressure and temperature, which are sufficient to ignite the diluted stoichiometric

  4. Polycrystalline diamond detectors with three-dimensional electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Lagomarsino, S., E-mail: lagomarsino@fi.infn.it [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Bellini, M. [INO-CNR Firenze, Largo E. Fermi 6, 50125 Firenze (Italy); Brianzi, M. [INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Carzino, R. [Smart Materials-Nanophysics, Istituto Italiano di Tecnologia, Genova, Via Morego 30, 16163 Genova (Italy); Cindro, V. [Joseph Stefan Institute, Jamova Cesta 39, 1000 Ljubljana (Slovenia); Corsi, C. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); LENS Firenze, Via N. Carrara 1, 50019 Sesto Fiorentino (Italy); Morozzi, A.; Passeri, D. [INFN Perugia, Perugia (Italy); Università degli Studi di Perugia, Dipartimento di Ingegneria, via G. Duranti 93, 06125 Perugia (Italy); Sciortino, S. [University of Florence, Department of Physics, Via Sansone 1, 50019 Sesto Fiorentino (Italy); INFN Firenze, Via B. Rossi 1, 50019 Sesto Fiorentino (Italy); Servoli, L. [INFN Perugia, Perugia (Italy)

    2015-10-01

    The three-dimensional concept in diamond detectors has been applied, so far, to high quality single-crystal material, in order to test this technology in the best available conditions. However, its application to polycrystalline chemical vapor deposited diamond could be desirable for two reasons: first, the short inter-electrode distance of three-dimensional detectors should improve the intrinsically lower collection efficiency of polycrystalline diamond, and second, at high levels of radiation damage the performances of the poly-crystal material are not expected to be much lower than those of the single crystal one. We report on the fabrication and test of three-dimensional polycrystalline diamond detectors with several inter-electrode distances, and we demonstrate that their collection efficiency is equal or higher than that obtained with conventional planar detectors fabricated with the same material. - Highlights: • Pulsed laser fabrication of polycristalline diamond detectors with 3D electrodes. • Measurement of the charge collection efficiency (CCE) under beta irradiation. • Comparation between the CCE of 3D and conventional planar diamond sensors. • A rationale for the behavior of three-dimensional and planar sensors is given.

  5. Loop expansion in massless three-dimensional QED

    International Nuclear Information System (INIS)

    Guendelman, E.I.; Radulovic, Z.M.

    1983-01-01

    It is shown how the loop expansion in massless three-dimensional QED can be made finite, up to three loops, by absorbing the infrared divergences in a gauge-fixing term. The same method removes leading and first subleading singularities to all orders of perturbation theory, and all singularities of the fermion self-energy to four loops

  6. Three-dimensional models of the tracheostoma using stereolithography

    NARCIS (Netherlands)

    Grolman, W.; Schouwenburg, P. F.; Verbeeten, B.; de Boer, M. F.; Meeuwis, C. A.

    1995-01-01

    The availability of an accurate three-dimensional (3-D) model of the tracheostoma and trachea of the laryngectomy patient would be of great help in prototyping of endotracheal prostheses. Stereolithography has been described for skull and jaw models but never for soft-tissue reconstructions of the

  7. Three-dimensional ultrasound strain imaging of skeletal muscles

    NARCIS (Netherlands)

    Gijsbertse, Kaj; Sprengers, Andre M.; Nillesen, Maartje; Hansen, Hendrik H.G.; Verdonschot, Nico; De Korte, Chris L.

    2015-01-01

    Muscle contraction is characterized by large deformation and translation, which requires a multi-dimensional imaging modality to reveal its behavior. Previous work on ultrasound strain imaging of the muscle contraction was limited to 2D and bi-plane techniques. In this study, a three-dimensional

  8. Kondo effect in three-dimensional Dirac and Weyl systems

    NARCIS (Netherlands)

    Mitchell, Andrew K.; Fritz, Lars

    2015-01-01

    Magnetic impurities in three-dimensional Dirac and Weyl systems are shown to exhibit a fascinatingly diverse range of Kondo physics, with distinctive experimental spectroscopic signatures. When the Fermi level is precisely at the Dirac point, Dirac semimetals are in fact unlikely candidates for a

  9. Generation of a Desired Three-Dimensional Electromagnetic Field

    DEFF Research Database (Denmark)

    2005-01-01

    The present invention relates to a method and a system for synthesizing a prescribed three-dimensional electromagnetic field based on generalized phase contrast imaging. Such a method and apparatus may be utilized in advanced optical micro and nano-manipulation, such as by provision of a multiple...

  10. Three-dimensional coupled double-distribution-function lattice ...

    Indian Academy of Sciences (India)

    Ruo-Fan Qiu

    2017-11-14

    Nov 14, 2017 ... Abstract. Two three-dimensional (3D) lattice Boltzmann models in the framework of coupled double-distribution- function approach for compressible flows, in which specific-heat ratio and Prandtl number can be adjustable, are developed in this paper. The main differences between the two models are ...

  11. Three-dimensional face shape in Fabry disease

    NARCIS (Netherlands)

    Cox-Brinkman, Josanne; Vedder, Anouk; Hollak, Carla; Richfield, Linda; Mehta, Atul; Orteu, Kate; Wijburg, Frits; Hammond, Peter

    2007-01-01

    Facial dysmorphology is an important feature in several lysosomal storage disorders. Although in Fabry disease facial dysmorphism is not a prominent sign, minor facial abnormalities have been previously reported. By analysing three-dimensional images of faces, we quantified facial dysmorphology in a

  12. Three dimensional reconstruction of tomographic images of the retina

    International Nuclear Information System (INIS)

    Glittenberg, C.; Zeiler, F.; Falkner, C.; Binder, S.; Povazay, B.; Hermann, B.; Drexler, W.

    2007-01-01

    The development of a new display system for the three-dimensional visualization of tomographic images in ophthalmology. Specifically, a system that can use stacks of B-mode scans from an ultrahigh resolution optical tomography examination to vividly display retinal specimens as three-dimensional objects. Several subroutines were programmed in the rendering and raytracing program Cinema 4D XL 9.102 Studio Bundle (Maxon Computer Inc., Friedrichsburg, Germany), which could process stacks of tomographic scans into three-dimensional objects. Ultrahigh resolution optical coherence tomography examinations were performed on patients with various retinal pathologies and post processed with the subroutines that had been designed. All ultrahigh resolution optical coherence tomographies were performed with a titanium: sapphire based ultra broad bandwidth (160 nm) femtosecond laser system (INTEGRAL, Femtolasers Productions GmbH. Vienna Austria) with an axial resolution of 3 μm. A new three dimensional display system for tomographic images in ophthalmology was developed, which allows a highly vivid display of physiological and pathological structures of the retina. The system also distinguishes itself through its high interactivity and adaptability. This new display system allows the visualization of physiological and pathological structures of the retina in a new way, which will give us new insight into their morphology and development. (author) [de

  13. Numerical Investigation of Three-dimensional Instability of Standing Waves

    Science.gov (United States)

    Zhu, Qiang; Liu, Yuming; Yue, Dick K. P.

    2002-11-01

    We study the three-dimensional instability of finite-amplitude standing waves under the influence of gravity using the transition matrix method. For accurate calculation of the transition matrices, we apply an efficient high-order spectral element method for nonlinear wave dynamics in complex domain. We consider two types of standing waves: (a) plane standing waves; and (b) standing waves in a circular tank. For the former, in addition to the confirmation of the side-band-like instability, we find a new three-dimensional instability for arbitrary base standing waves. The dominant component of the unstable disturbance is an oblique standing wave, with an arbitrary angle relative to the base flow, whose frequency is approximately equal to that of the base standing wave. Based on direct simulations, we confirm such a three-dimensional instability and show the occurrence of the Fermi-Pasta-Ulam recurrence phenomenon during nonlinear evolution. For the latter, we find that beyond a threshold wave steepness, the standing wave with frequency Ω becomes unstable to a small three-dimensional disturbance, which contains two dominant standing-wave components with frequencies ω1 and ω_2, provided that 2Ω ω1 + ω_2. The threshold wave steepness is found to decrease/increase as the radial/azimuthal wavenumber of the base standing wave increases. We show that the instability of standing waves in rectangular and circular tanks is caused by third-order quartet resonances between base flow and disturbance.

  14. Wave packet construction in three-dimensional quantum billiards ...

    Indian Academy of Sciences (India)

    E-mail: mannu_711@yahoo.co.in. MS received 14 ... The motivation to extend the study to a three-dimensional (3D) system is .... with a GWP centred around the central value of the principle quantum number n0 instead of a GWP ...... Cubical and parallelepiped billiards are the potential candidates for the creation of arti-.

  15. Green function of a three-dimensional Wick problem

    International Nuclear Information System (INIS)

    Matveev, V.A.

    1988-01-01

    An exact solution of a three-dimensional Coulomb Wick-Cutkovsky problem has been obtained which possesses the hidden 0(4)-symmetry. Here we shell give the derivation of the corresponding Green function and consider its connection with the asymptoric behaviour of the scattering amplitude. 9 refs

  16. Three-Dimensional Gauge Theories and ADE Monopoles

    OpenAIRE

    Tong, David

    1998-01-01

    We study three-dimensional N=4 gauge theories with product gauge groups constructed from ADE Dynkin diagrams. One-loop corrections to the metric on the Coulomb branch are shown to coincide with the metric on the moduli space of well-seperated ADE monopoles. We propose that this correspondence is exact.

  17. Three-dimensional simulations of free-electron laser physics

    International Nuclear Information System (INIS)

    McVey, B.D.

    1985-09-01

    A computer code has been developed to simulate three-dimensional free-electron laser physics. A mathematical formulation of the FEL equations is presented, and the numerical solution of the problem is described. Sample results from the computer code are discussed. 23 refs., 6 figs., 2 tabs

  18. Three-dimensional organization of the human interphase nucleus

    NARCIS (Netherlands)

    T.A. Knoch (Tobias); C. Münkel (Christian); W. Waldeck (Waldemar); J. Langowski (Jörg)

    2000-01-01

    textabstractDespite the successful linear sequencing of the human genome its three-dimensional structure is widely unknown, although it is important for gene regulation and replication. For a long time the interphase nucleus has been viewed as a 'spaghetti soup' of DNA without much internal

  19. Birkhoff's Theorem for Three-Dimensional AdS Gravity

    OpenAIRE

    Ayón-Beato, Eloy; Martínez, Cristián; Zanelli, Jorge

    2004-01-01

    All three-dimensional matter-free spacetimes with negative cosmological constant, compatible with cyclic symmetry are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2) x R isometry, and the self-dual Coussaert-Henneaux spacetimes, with isometry groups SO(2) x SO(2,1) or SO(2) x SO(2).

  20. Fabrication of three-dimensional carbon microelectrodes for electrochemical sensing

    DEFF Research Database (Denmark)

    Hemanth, Suhith

    Carbon microelectrodes have a wide range of applications because of their unique material properties and biocompatibility. The aim of the research work carried out in this thesis was to develop three-dimensional (3D) carbon microelectrodes for electrochemical applications. Three different fabrica...

  1. Three-dimensional echocardiographic assessment of the repaired mitral valve.

    Science.gov (United States)

    Maslow, Andrew; Mahmood, Feroze; Poppas, Athena; Singh, Arun

    2014-02-01

    This study examined the geometric changes of the mitral valve (MV) after repair using conventional and three-dimensional echocardiography. Prospective evaluation of consecutive patients undergoing mitral valve repair. Tertiary care university hospital. Fifty consecutive patients scheduled for elective repair of the mitral valve for regurgitant disease. Intraoperative transesophageal echocardiography. Assessments of valve area (MVA) were performed using two-dimensional planimetry (2D-Plan), pressure half-time (PHT), and three-dimensional planimetry (3D-Plan). In addition, the direction of ventricular inflow was assessed from the three-dimensional imaging. Good correlations (r = 0.83) and agreement (-0.08 +/- 0.43 cm(2)) were seen between the MVA measured with 3D-Plan and PHT, and were better than either compared to 2D-Plan. MVAs were smaller after repair of functional disease repaired with an annuloplasty ring. After repair, ventricular inflow was directed toward the lateral ventricular wall. Subgroup analysis showed that the change in inflow angle was not different after repair of functional disease (168 to 171 degrees) as compared to those presenting with degenerative disease (168 to 148 degrees; p<0.0001). Three-dimensional imaging provides caregivers with a unique ability to assess changes in valve function after mitral valve repair. Copyright © 2014 Elsevier Inc. All rights reserved.

  2. Mathematical modeling of three-dimensional images in emission tomography

    International Nuclear Information System (INIS)

    Koblik, Yu.N.; Khugaev, A. V.; Mktchyan, G.A.; Ioannou, P.; Dimovasili, E.

    2002-01-01

    The model of processing results of three-dimensional measurements in positron-emissive tomograph is proposed in this work. The algorithm of construction and visualization of phantom objects of arbitrary shape was developed and its concrete realization in view of program packet for PC was carried out

  3. Three-dimensional image reconstruction from stereo DSA

    International Nuclear Information System (INIS)

    Sakamoto, Kiyoshi; Kotoura, Noriko; Umehara, Takayoshi; Yamada, Eiji; Inaba, Tomohiro; Itou, Hiroshi

    1999-01-01

    The technique of interventional radiology has spread rapidly in recent years, and three-dimensional information from blood vessel images is being sought to enhance examinations. Stereo digital subtraction angiography (DSA) and rotational DSA were developed for that purpose. However, it is difficult with stereo DSA to observe the image pair during examination and to obtain positional information on blood vessels. Further, the exposure dose is increased in rotational DSA when many mask images need to be collected, and the patient is required to hold his or her breath for a long duration. We therefore devised a technique to construct three-dimensional blood vessel images by employing geometrical information extracted from stereo DSA images using the right and left images. We used a judgment method based on the correlation coefficient, although we had to extract an equal blood vessel from the right and left images to determine the three-dimensional coordinates of the blood vessel. The reconstructed three-dimensional blood vessels were projected from various angles, again by using a virtual focus, and new images were created. These image groups were displayed as rotational images by the animation display function incorporated in the DSA device. This system can observe blood vessel images of the same phase at a free angle, although the image quality is inferior to that of rotational DSA. In addition, because collection of the mask images is reduced, exposure dose can be decreased. Further, the system offers enhanced safety because no mechanical movement of the imaging system is involved. (author)

  4. Three-dimensional computer models of electrospinning systems

    Directory of Open Access Journals (Sweden)

    Smółka Krzysztof

    2017-12-01

    Full Text Available Electrospinning is a very interesting method that allows the fabrication of continuous fibers with diameters down to a few nanometers. This paper presents an overview of electrospinning systems as well as their comparison using proposed three-dimensional parameterized numerical models. The presented solutions allow an analysis of the electric field distribution.

  5. Three-Dimensional Structure of CeO2 Nanocrystals

    DEFF Research Database (Denmark)

    Tan, Joyce Pei Ying; Tan, Hui Ru; Boothroyd, Chris

    2011-01-01

    Visualization of three-dimensional (3D) structures of materials at the nanometer scale can shed important information on the performance of their applications and provide insight into the growth mechanism of shape-controlled nanomaterials. In this paper, the 3D structures and growth pathway of Ce...

  6. Three dimensional simulated modelling of diffusion capacitance of ...

    African Journals Online (AJOL)

    A three dimensional (3-D) simulated modelling was developed to analyse the excess minority carrier density in the base of a polycrystalline bifacial silicon solar cell. The concept of junction recombination velocity was ado-pted to quantify carrier flow through the junction, and to examine the solar cell diffusion capacitance for ...

  7. Signal processing of eddy current three-dimensional maps

    International Nuclear Information System (INIS)

    Birac, C.; David, D.; Lamant, D.

    1987-01-01

    Digital processing of eddy current three-dimensional maps improves accuracy of detection: flattening, filtering, computing deconvolution, mapping new variables,.., give new possibilities for difficult test problems. With simulation of defects, probes, probe travels, it is now possible to compute new eddy current processes, without machining defects or building probes

  8. Backlund transformations and three-dimensional lattice equations

    NARCIS (Netherlands)

    Nijhoff, F.W.; Capel, H.W.; Wiersma, G.L.; Quispel, G.R.W.

    1984-01-01

    A (nonlocal) linear integral equation is studied, which allows for Bäcklund transformations in the measure. The compatibility of three of these transformations leads to an integrable nonlinear three-dimensional lattice equation. In appropriate continuum limits the two-dimensional Toda-lattice

  9. A Novel Three-Dimensional Tool for Teaching Human Neuroanatomy

    Science.gov (United States)

    Estevez, Maureen E.; Lindgren, Kristen A.; Bergethon, Peter R.

    2010-01-01

    Three-dimensional (3D) visualization of neuroanatomy can be challenging for medical students. This knowledge is essential in order for students to correlate cross-sectional neuroanatomy and whole brain specimens within neuroscience curricula and to interpret clinical and radiological information as clinicians or researchers. This study implemented…

  10. Oblique water entry of a three dimensional body

    Directory of Open Access Journals (Sweden)

    Scolan Yves-Marie

    2014-12-01

    Full Text Available The problem of the oblique water entry of a three dimensional body is considered. Wagner theory is the theoretical framework. Applications are discussed for an elliptic paraboloid entering an initially flat free surface. A dedicated experimental campaign yields a data base for comparisons. In the present analysis, pressure, force and dynamics of the wetted surface expansion are assessed.

  11. Splines under tension for gridding three-dimensional data

    International Nuclear Information System (INIS)

    Brand, H.R.; Frazer, J.W.

    1982-01-01

    By use of the splines-under-tension concept, a simple algorithm has been developed for the three-dimensional representation of nonuniformly spaced data. The representations provide useful information to the experimentalist when he is attempting to understand the results obtained in a self-adaptive experiment. The shortcomings of the algorithm are discussed as well as the advantages

  12. Approaching the Sequential and Three-Dimensional Organization of Genomes

    NARCIS (Netherlands)

    T.A. Knoch (Tobias)

    2006-01-01

    textabstractGenomes are one of the major foundations of life due to their role in information storage, process regulation and evolution. To achieve a deeper unterstanding of the human genome the three-dimensional organization of the human cell nucleus, the structural-, scaling- and dynamic

  13. Evaluation of three-dimensional virtual perception of garments

    Science.gov (United States)

    Aydoğdu, G.; Yeşilpinar, S.; Erdem, D.

    2017-10-01

    In recent years, three-dimensional design, dressing and simulation programs came into prominence in the textile industry. By these programs, the need to produce clothing samples for every design in design process has been eliminated. Clothing fit, design, pattern, fabric and accessory details and fabric drape features can be evaluated easily. Also, body size of virtual mannequin can be adjusted so more realistic simulations can be created. Moreover, three-dimensional virtual garment images created by these programs can be used while presenting the product to end-user instead of two-dimensional photograph images. In this study, a survey was carried out to investigate the visual perception of consumers. The survey was conducted for three different garment types, separately. Questions about gender, profession etc. was asked to the participants and expected them to compare real samples and artworks or three-dimensional virtual images of garments. When survey results were analyzed statistically, it is seen that demographic situation of participants does not affect visual perception and three-dimensional virtual garment images reflect the real sample characteristics better than artworks for each garment type. Also, it is reported that there is no perception difference depending on garment type between t-shirt, sweatshirt and tracksuit bottom.

  14. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    International Nuclear Information System (INIS)

    Cavinato, Christianne C.; Campos, Leticia L.; Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B.; Giordani, Adelmo J.

    2011-01-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  15. FXG dosimeter response for three-dimensional conformal radiotherapy using different evaluation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.b, E-mail: lcrodri@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil); Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B., E-mail: bhsouza@unifesp.b, E-mail: daros.kellen@unifesp.b, E-mail: rbitel-li.ddi@epm.b [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagem; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Servico de Radioterapia

    2011-07-01

    This work aims to compare the dose-response of the Fricke xylenol gel (FXG) dosimeter developed at IPEN using 270 Bloom gelatin from porcine skin made in Brazil evaluated using the magnetic resonance imaging (MRI) technique with the dosimetric response evaluated using the optical absorption (OA) spectrophotometry technique, in order to verify the possibility of quality assurance (QA) and reproducibility of FXG dosimeter to be carried out routinely using the OA technique for three-dimensional conformal radiotherapy (3DCRT) application using a 6 MV photons linear accelerator. The response in function of the absorbed dose of FXG dosimeter developed at IPEN presents linear behavior in clinical interest dose range when irradiated with Co-60 gamma radiation and 6 MV photons and evaluated using the MRI and OA techniques. The results indicate that the optical technique can be used for QA of FXG dosemeter when used in the possible application in QA of 3DCRT. (author)

  16. Nematic order on the surface of a three-dimensional topological insulator

    Science.gov (United States)

    Lundgren, Rex; Yerzhakov, Hennadii; Maciejko, Joseph

    2017-12-01

    We study the spontaneous breaking of rotational symmetry in the helical surface state of three-dimensional topological insulators due to strong electron-electron interactions, focusing on time-reversal invariant nematic order. Owing to the strongly spin-orbit coupled nature of the surface state, the nematic order parameter is linear in the electron momentum and necessarily involves the electron spin, in contrast with spin-degenerate nematic Fermi liquids. For a chemical potential at the Dirac point (zero doping), we find a first-order phase transition at zero temperature between isotropic and nematic Dirac semimetals. This extends to a thermal phase transition that changes from first to second order at a finite-temperature tricritical point. At finite doping, we find a transition between isotropic and nematic helical Fermi liquids that is second order even at zero temperature. Focusing on finite doping, we discuss various observable consequences of nematic order, such as anisotropies in transport and the spin susceptibility, the partial breakdown of spin-momentum locking, collective modes and induced spin fluctuations, and non-Fermi-liquid behavior at the quantum critical point and in the nematic phase.

  17. Three-dimensional finite element models of the human pubic symphysis with viscohyperelastic soft tissues.

    Science.gov (United States)

    Li, Zuoping; Alonso, Jorge E; Kim, Jong-Eun; Davidson, James S; Etheridge, Brandon S; Eberhardt, Alan W

    2006-09-01

    Three-dimensional finite element (FE) models of human pubic symphyses were constructed from computed tomography image data of one male and one female cadaver pelvis. The pubic bones, interpubic fibrocartilaginous disc and four pubic ligaments were segmented semi-automatically and meshed with hexahedral elements using automatic mesh generation schemes. A two-term viscoelastic Prony series, determined by curve fitting results of compressive creep experiments, was used to model the rate-dependent effects of the interpubic disc and the pubic ligaments. Three-parameter Mooney-Rivlin material coefficients were calculated for the discs using a heuristic FE approach based on average experimental joint compression data. Similarly, a transversely isotropic hyperelastic material model was applied to the ligaments to capture average tensile responses. Linear elastic isotropic properties were assigned to bone. The applicability of the resulting models was tested in bending simulations in four directions and in tensile tests of varying load rates. The model-predicted results correlated reasonably with the joint bending stiffnesses and rate-dependent tensile responses measured in experiments, supporting the validity of the estimated material coefficients and overall modeling approach. This study represents an important and necessary step in the eventual development of biofidelic pelvis models to investigate symphysis response under high-energy impact conditions, such as motor vehicle collisions.

  18. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    Directory of Open Access Journals (Sweden)

    Wendy Whiteside

    2015-01-01

    Full Text Available Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver.

  19. Three-dimensional magnetic resonance imaging overlay to assist with percutaneous transhepatic access at the time of cardiac catheterization

    International Nuclear Information System (INIS)

    Whiteside, Wendy; Christensen, Jason; Zampi, Jeffrey D

    2005-01-01

    Multimodality image overlay is increasingly used for complex interventional procedures in the cardiac catheterization lab. We report a case in which three-dimensional magnetic resonance imaging (3D MRI) overlay onto live fluoroscopic imaging was utilized to safely obtain transhepatic access in a 12-year-old patient with prune belly syndrome, complex and distorted abdominal anatomy, and a vascular mass within the liver

  20. Informatics solutions for Three-dimensional visualization in real time

    International Nuclear Information System (INIS)

    Guzman Montoto, Jose Ignacio

    2002-01-01

    The advances reached in the development of the hardware and in the methods of acquisition of data like tomographic scanners and systems of analysis of images, have allowed obtaining geometric models of biomedical elements with the property of being manipulated through the three-dimensional visualization (3D). Nowadays, this visualization embraces from biological applications, including analysis of structures and its functional relationships, until medical applications that include anatomical accuracies and the planning or the training for complex surgical operations. This work proposes computer solutions to satisfy visualization requirements in real time. The developed algorithms are contained in a graphic library that will facilitate the development of future works. The obtained results allow facing current problems of three-dimensional representation of complex surfaces, realism is reached in the images and they have possible application in bioinformatics and medicine

  1. Visualization of traumatic tricuspid insufficiency by three-dimensional echocardiography.

    Science.gov (United States)

    Nishimura, Kazuhisa; Okayama, Hideki; Inoue, Katsuji; Saito, Makoto; Nagai, Takayuki; Suzuki, Jun; Ogimoto, Akiyoshi; Ohtsuka, Tomoaki; Higaki, Jitsuo

    2010-01-01

    A 19-year-old male was admitted to the emergency room of our hospital after a motor vehicle accident. During his first physical examination, a holosystolic murmur was heard at the fourth left parasternal border. Transthoracic echocardiography showed severe tricuspid insufficiency, but the cause of tricuspid insufficiency was unclear. Therefore, three-dimensional echocardiography was performed and demonstrated flail anterior, posterior and septal leaflets of the tricuspid valve. The diagnosis was tricuspid insufficiency due to papillary muscle rupture secondary to chest blunt trauma. Surgical repair of the tricuspid valve was performed in this patient. After surgery, the signs and symptoms of right ventricular heart failure were relieved. In this case, three-dimensional echocardiography was very useful for the evaluation of spatial destruction of the tricuspid valve and papillary muscle. 2009 Japanese College of Cardiology. Published by Elsevier Ltd. All rights reserved.

  2. Three-dimensional simulations of Nova capsule implosion experiments

    International Nuclear Information System (INIS)

    Marinak, M.M.; Tipton, R.E.; Landen, O.L.

    1995-01-01

    Capsule implosion experiments carried out on the Nova laser are simulated with the three-dimensional HYDRA radiation hydrodynamics code. Simulations of ordered near single mode perturbations indicate that structures which evolve into round spikes can penetrate farthest into the hot spot. Bubble-shaped perturbations can burn through the capsule shell fastest, however, causing even more damage. Simulations of a capsule with multimode perturbations shows spike amplitudes evolving in good agreement with a saturation model during the deceleration phase. The presence of sizable low mode asymmetry, caused either by drive asymmetry or perturbations in the capsule shell, can dramatically affect the manner in which spikes approach the center of the hot spot. Three-dimensional coupling between the low mode shell perturbations intrinsic to Nova capsules and the drive asymmetry brings the simulated yields into closer agreement with the experimental values

  3. Three-dimensional MR imaging of congenital heart disease

    International Nuclear Information System (INIS)

    Laschinger, J.C.; Vannier, M.W.; Knapp, R.H.; Gutierrez, F.R.; Cox, J.L.

    1987-01-01

    Contiguous 5-mm thick ECG-gated MR images of the thorax were edited using surface reconstruction techniques to produce three-dimensional (3D) images of the heart and great vessels in four healthy individuals and 25 patients with congenital heart disease (aged 3 months-30 years). Anomalies studied include atrial and ventricular septal defects, aortic coarctation, AV canal defects, double outlet ventricles, hypoplastic left heart syndrome, and a wide spectrum of patients with tetralogy of Fallot. The results were correlated with echocardiographic and cineradiographic studies, and with surgical findings or pathologic specimens. Three-dimensional reconstructions accurately localized the dimensions and locations of all cardiac and great vessel anomalies and often displayed anatomic findings not diagnosed or visualized with other forms of diagnostic imaging

  4. Secondary instability and transition in three-dimensional boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, A.; Bertolotti, F.P.; Koch, W. (Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany). Inst. fuer Stroemungsmechanik)

    1999-01-01

    Stationary and traveling crossflow modes are the most prominent disturbances in the highly accelerated three-dimensional flow near the leading edge of a swept wing. Near transition onset, secondary three-dimensional instabilities of high frequency can be observed in such flows. A model flow on the basis of a DLR swept plate experiment allows a detailed study of transition scenarios triggered by crossflow instabilities, since the favorable pressure gradient over the whole plate inhibits instabilities of Tollmien-Schlichting type. In order to shed some light upon the role of the high-frequency secondary instabilities, the saturation characteristics of crossflow vortices in this model flow are investigated using the parabolized stability equations. In contrast to nonlinear equilibrium solutions of steady crossflow vortices, the nonlinear Polarized Stability Equations (PSE) results yield different maximal disturbance amplitudes for different initial amplitudes. (orig./AKF)

  5. Secondary instability and transition in three-dimensional boundary layers

    Energy Technology Data Exchange (ETDEWEB)

    Stolte, A.; Bertolotti, F.P.; Koch, W. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Goettingen (Germany). Inst. fuer Stroemungsmechanik

    1999-12-01

    Stationary and traveling crossflow modes are the most prominent disturbances in the highly accelerated three-dimensional flow near the leading edge of a swept wing. Near transition onset, secondary three-dimensional instabilities of high frequency can be observed in such flows. A model flow on the basis of a DLR swept plate experiment allows a detailed study of transition scenarios triggered by crossflow instabilities, since the favorable pressure gradient over the whole plate inhibits instabilities of Tollmien-Schlichting type. In order to shed some light upon the role of the high-frequency secondary instabilities, the saturation characteristics of crossflow vortices in this model flow are investigated using the parabolized stability equations. In contrast to nonlinear equilibrium solutions of steady crossflow vortices, the nonlinear Polarized Stability Equations (PSE) results yield different maximal disturbance amplitudes for different initial amplitudes. (orig./AKF)

  6. Three-dimensional metallic opals fabricated by double templating

    International Nuclear Information System (INIS)

    Yan Qingfeng; Nukala, Pavan; Chiang, Yet-Ming; Wong, C.C.

    2009-01-01

    We report a simple and cost-effective double templating method for fabricating large-area three-dimensional metallic photonic crystals of controlled thickness. A self-assembled polystyrene opal was used as the first template to fabricate a silica inverse opal on a gold-coated glass substrate via sol-gel processing. Gold was subsequently infiltrated to the pores of the silica inverse opal using electrochemical deposition. A high-quality three-dimensional gold photonic crystal was obtained after removal of the secondary template (silica inverse opal). The effects of template sphere size and deposition current density on the gold growth rate, and the resulting morphology and growth mechanism of the gold opal, were investigated.

  7. Three-dimensional P velocity structure in Beijing area

    Science.gov (United States)

    Yu, Xiang-Wei; Chen, Yun-Tai; Wang, Pei-De

    2003-01-01

    A detail three-dimensional P wave velocity structure of Beijing, Tianjin and Tangshan area (BTT area) was determined by inverting local earthquake data. In total 16 048 P wave first arrival times from 16048 shallow and mid-depth crustal earthquakes, which occurred in and around the BTT area from 1992 to 1999 were used. The first arrival times are recorded by Northern China United Telemetry Seismic Network and Yanqing-Huailai Digital Seismic Network. Hypocentral parameters of 1 132 earthquakes with magnitude M L=1.7 6.2 and the three-dimensional P wave velocity structure were obtained simultaneously. The inversion result reveals the complicated lateral heterogeneity of P wave velocity structure around BTT area. The tomographic images obtained are also found to explain other seismological observations well.

  8. Quasi-three-dimensional particle imaging with digital holography.

    Science.gov (United States)

    Kemppinen, Osku; Heinson, Yuli; Berg, Matthew

    2017-05-01

    In this work, approximate three-dimensional structures of microparticles are generated with digital holography using an automated focus method. This is done by stacking a collection of silhouette-like images of a particle reconstructed from a single in-line hologram. The method enables estimation of the particle size in the longitudinal and transverse dimensions. Using the discrete dipole approximation, the method is tested computationally by simulating holograms for a variety of particles and attempting to reconstruct the known three-dimensional structure. It is found that poor longitudinal resolution strongly perturbs the reconstructed structure, yet the method does provide an approximate sense for the structure's longitudinal dimension. The method is then applied to laboratory measurements of holograms of single microparticles and their scattering patterns.

  9. Three-Dimensional Flow Behavior Inside the Submerged Entry Nozzle

    Science.gov (United States)

    Real-Ramirez, Cesar Augusto; Carvajal-Mariscal, Ignacio; Sanchez-Silva, Florencio; Cervantes-de-la-Torre, Francisco; Diaz-Montes, Jesus; Gonzalez-Trejo, Jesus

    2018-05-01

    According to various authors, the surface quality of steel depends on the dynamic conditions that occur within the continuous casting mold's upper region. The meniscus, found in that upper region, is where the solidification process begins. The liquid steel is distributed into the mold through a submerged entry nozzle (SEN). In this paper, the dynamic behavior inside the SEN is analyzed by means of physical experiments and numerical simulations. The particle imaging velocimetry technique was used to obtain the vector field in different planes and three-dimensional flow patterns inside the SEN volume. Moreover, large eddy simulation was performed, and the turbulence model results were used to understand the nonlinear flow pattern inside the SEN. Using scaled physical and numerical models, quasi-periodic behavior was observed due to the interaction of two three-dimensional vortices that move inside the SEN lower region located between the exit ports of the nozzle.

  10. Three-dimensional computerized tomography in mandibular condyle fractures

    International Nuclear Information System (INIS)

    Bermeo, Fausto; Salazar, Abad

    2003-01-01

    Now, car accidents are so commons, this associated to the high technology in produce automobiles make this type of accidents so serious and the consequences of mandibular condyle fractures are more commons and with more gravity, some of these patients, generally need a traqueostomy to be operated, that is why every second that we can save during the surgery is important. The normal exams as X rays and simple TAC give as an important idea but no complete, on the contrary the three-dimensional TAC permits to observe every damages and its exact location, this contribute to make a better surgery organization, the number and type of plates that we have to put and the better way to treat each case, that contribute to reduce time in operating theatre which is in benefit of the patient, diminishing risks in serious patients as they are, that is why we recommend the utilization of the three-dimensional TAC. (The author)

  11. Handwriting: three-dimensional kinetic synergies in circle drawing movements.

    Science.gov (United States)

    Hooke, Alexander W; Karol, Sohit; Park, Jaebum; Kim, Yoon Hyuk; Shim, Jae Kun

    2012-07-01

    The purpose of this study was to investigate central nervous system (CNS) strategies for controlling multifinger forces during a circle-drawing task. Subjects drew 30 concentric, discontinuous clockwise and counter clockwise circles, at self and experimenter-set paces. The three-dimensional trajectory of the pen's center of mass and the three-dimensional forces and moments of force at each contact between the hand and the pen were recorded. Uncontrolled Manifold Analysis was used to quantify the synergies between pen-hand contact forces in radial, tangential and vertical directions. Results showed that synergies in the radial and tangential components were significantly stronger than in the vertical component. Synergies in the clockwise direction were significantly stronger than the counterclockwise direction in the radial and vertical components. Pace was found to be insignificant under any condition.

  12. Three Dimensional Energy Transmitting Boundary in the Time Domain

    Directory of Open Access Journals (Sweden)

    Naohiro eNakamura

    2015-11-01

    Full Text Available Although the energy transmitting boundary is accurate and efficient for the FEM earthquake response analysis, it could be applied in the frequency domain only. In the previous papers, the author proposed an earthquake response analysis method using the time domain energy transmitting boundary for two dimensional problems. In this paper, this technique is expanded for three dimensional problems. The inner field is supposed to be a hexahedron shape and the approximate time domain boundary is explained, first. Next, two dimensional anti-plane time domain boundary is studied for a part of the approximate three dimensional boundary method. Then, accuracy and efficiency of the proposed method are confirmed by example problems.

  13. Canonical and symplectic analysis for three dimensional gravity without dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Escalante, Alberto, E-mail: aescalan@ifuap.buap.mx [Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apartado Postal J-48 72570, Puebla, Pue. (Mexico); Osmart Ochoa-Gutiérrez, H. [Facultad de Ciencias Físico Matemáticas, Benemérita Universidad Autónoma de Puebla, Apartado postal 1152, 72001 Puebla, Pue. (Mexico)

    2017-03-15

    In this paper a detailed Hamiltonian analysis of three-dimensional gravity without dynamics proposed by V. Hussain is performed. We report the complete structure of the constraints and the Dirac brackets are explicitly computed. In addition, the Faddeev–Jackiw symplectic approach is developed; we report the complete set of Faddeev–Jackiw constraints and the generalized brackets, then we show that the Dirac and the generalized Faddeev–Jackiw brackets coincide to each other. Finally, the similarities and advantages between Faddeev–Jackiw and Dirac’s formalism are briefly discussed. - Highlights: • We report the symplectic analysis for three dimensional gravity without dynamics. • We report the Faddeev–Jackiw constraints. • A pure Dirac’s analysis is performed. • The complete structure of Dirac’s constraints is reported. • We show that symplectic and Dirac’s brackets coincide to each other.

  14. The thermoelectric performance of bulk three-dimensional graphene

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Zhi, E-mail: yangzhi@tyut.edu.cn [Key Lab of Advanced Transducers and Intelligent Control System, Ministry of Education and Shanxi Province, Taiyuan University of Technology, Taiyuan 030024 (China); College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Lan, Guoqiang; Ouyang, Bin [Department of Mining and Materials Engineering, McGill University, Montreal H3A 0C5 (Canada); Xu, Li-Chun; Liu, Ruiping [College of Physics and Optoelectronics, Taiyuan University of Technology, Taiyuan 030024 (China); Liu, Xuguang, E-mail: liuxuguang@tyut.edu.cn [Key Lab of Interface Science and Engineering in Advanced Materials, Ministry of Education, Taiyuan University of Technology, Taiyuan 030024 (China); College of Chemistry and Chemical Engineering, Taiyuan University of Technology, Taiyuan 030024 (China); Song, Jun [Department of Mining and Materials Engineering, McGill University, Montreal H3A 0C5 (Canada)

    2016-11-01

    The electronic and thermoelectric properties of a new carbon bulk material, three-dimensional (3D) graphene, are investigated in this study. Our results show that 3D graphene has unique electronic structure, i.e., near the Fermi level there exist Dirac cones. More importantly, the thermoelectric performance of 3D graphene is excellent, at room temperature the thermoelectric figure of merit (ZT) is 0.21, an order of magnitude higher than that of graphene. By introducing line defects, the ZT of 3D graphene could be enhanced to 1.52, indicating 3D graphene is a powerful candidate for constructing novel thermoelectric materials. - Highlights: • There exist Dirac cones in three-dimensional (3D) graphene. • The thermoelectric performance of 3D graphene is excellent. • The defective 3D graphene has better thermoelectric performance.

  15. Three-dimensional Modeling of Type Ia Supernova Explosions

    Science.gov (United States)

    Khokhlov, Alexei

    2001-06-01

    A deflagration explosion of a Type Ia Supernova (SNIa) is studied using three-dimensional, high-resolution, adaptive mesh refinement fluid dynamic calculations. Deflagration speed in an exploding Chandrasekhar-mass carbon-oxygen white dwarf (WD) grows exponentially, reaches approximately 30the speed of sound, and then declines due to a WD expansion. Outermost layers of the WD remain unburned. The explosion energy is comparable to that of a Type Ia supernova. The freezing of turbulent motions by expansion appears to be a crucial physical mechanism regulating the strength of a supernova explosion. In contrast to one-dimensional models, three-dimensional calculations predict the formation of Si-group elements and pockets of unburned CO in the middle and in central regions of a supernova ejecta. This, and the presence of unburned outer layer of carbon-oxygen may pose problems for SNIa spectra. Explosion sensitivity to initial conditions and its relation to a diversity of SNIa is discussed.

  16. SNAP-3D: a three-dimensional neutron diffusion code

    International Nuclear Information System (INIS)

    McCallien, C.W.J.

    1975-10-01

    A preliminary report is presented describing the data requirements of a one- two- or three-dimensional multi-group diffusion code, SNAP-3D. This code is primarily intended for neutron diffusion calculations but it can also carry out gamma calculations if the diffuse approximation is accurate enough. It is suitable for fast and thermal reactor core calculations and for shield calculations. It is assumed the reader is familiar with the older, two-dimensional code SNAP and can refer to the report [TRG-Report-1990], describing it. The present report concentrates on the enhancements to SNAP that have been made to produce the three-dimensional version, SNAP-3D, and is intended to act a a guide on data preparation until a single, comprehensive report can be published. (author)

  17. Analytical Prediction of Three Dimensional Chatter Stability in Milling

    Science.gov (United States)

    Altintas, Yusuf

    The chip regeneration mechanism during chatter is influenced by vibrations in three directions when milling cutters with ball end, bull nose, or inclined cutting edges are used. A three dimensional chatter stability is modeled analytically in this article. The dynamic milling system is formulated as a function of cutter geometry, the frequency response of the machine tool structure at the cutting zone in three Cartesian directions, cutter engagement conditions and material property. The dynamic milling system with nonlinearities and periodic delayed differential equations is reduced to a three dimensional linear stability problem by approximations based on the physics of milling. The chatter stability lobes are predicted in the frequency domain using the proposed analytical solution, and verified experimentally in milling a Titanium alloy with a face milling cutter having circular inserts.

  18. Pattern formation and three-dimensional instability in rotating flows

    Science.gov (United States)

    Christensen, Erik A.; Aubry, Nadine; Sorensen, Jens N.

    1997-03-01

    A fluid flow enclosed in a cylindrical container where fluid motion is created by the rotation of one end wall as a centrifugal fan is studied. Direct numerical simulations and spatio-temporal analysis have been performed in the early transition scenario, which includes a steady-unsteady transition and a breakdown of axisymmetric to three-dimensional flow behavior. In the early unsteady regime of the flow, the central vortex undergoes a vertical beating motion, accompanied by axisymmetric spikes formation on the edge of the breakdown bubble. As traveling waves, the spikes move along the central vortex core toward the rotating end-wall. As the Reynolds number is increased further, the flow undergoes a three-dimensional instability. The influence of the latter on the previous patterns is studied.

  19. Three-dimensional theory for light-matter interaction

    DEFF Research Database (Denmark)

    Sørensen, Martin Westring; Sørensen, Anders Søndberg

    2008-01-01

    We present a full quantum mechanical three dimensional theory describing an electromagnetic field interacting with an ensemble of identical atoms. The theory is constructed such that it describes recent experiments on light-matter quantum interfaces, where the quantum fluctuations of light...... to a dressed state picture, where the light modes are solutions to the diffraction problem, and develop a perturbative expansion in the fluctuations. The fluctuations are due to quantum fluctuations as well as the random positions of the atoms. In this perturbative expansion we show how the quantum...... fluctuations are mapped between atoms and light while the random positioning of the atoms give rise to decay due to spontaneous emission. Furthermore we identify limits, where the full three dimensional theory reduce to the one dimensional theory typically used to describe the interaction....

  20. Three-dimensional imaging technology offers promise in medicine.

    Science.gov (United States)

    Karako, Kenji; Wu, Qiong; Gao, Jianjun

    2014-04-01

    Medical imaging plays an increasingly important role in the diagnosis and treatment of disease. Currently, medical equipment mainly has two-dimensional (2D) imaging systems. Although this conventional imaging largely satisfies clinical requirements, it cannot depict pathologic changes in 3 dimensions. The development of three-dimensional (3D) imaging technology has encouraged advances in medical imaging. Three-dimensional imaging technology offers doctors much more information on a pathology than 2D imaging, thus significantly improving diagnostic capability and the quality of treatment. Moreover, the combination of 3D imaging with augmented reality significantly improves surgical navigation process. The advantages of 3D imaging technology have made it an important component of technological progress in the field of medical imaging.

  1. Design of three-dimensional nonimaging concentrators with inhomogeneous media

    Science.gov (United States)

    Minano, J. C.

    1986-09-01

    A three-dimensional nonimaging concentrator is an optical system that transforms a given four-parametric manifold of rays reaching a surface (entry aperture) into another four-parametric manifold of rays reaching the receiver. A procedure of design of such concentrators is developed. In general, the concentrators use mirrors and inhomogeneous media (i.e., gradient-index media). The concentrator has the maximum concentration allowed by the theorem of conservation of phase-space volume. This is the first known concentrator with such properties. The Welford-Winston edge-ray principle in three-dimensional geometry is proven under several assumptions. The linear compound parabolic concentrator is derived as a particular case of the procedure of design.

  2. Single florescent nanodiamond in a three dimensional ABEL trap

    Science.gov (United States)

    Kayci, Metin; Radenovic, Aleksandra

    2015-01-01

    Three dimensional single particle trapping and manipulation is an outstanding challenge in various fields ranging from basic physics to life sciences. By monitoring the response of a trapped particle to a designed environment one can extract its characteristics. In addition, quantum dynamics of a spatially scanned well-known particle can provide environmental information. Precise tracking and positioning of such a particle in aqueous environment is crucial task for achieving nano-scale resolution. Here we experimentally demonstrate three dimensional ABEL trap operating at high frequency by employing a hybrid approach in particle tracking. The particle location in the transverse plane is detected via a scanning laser beam while the axial position is determined by defocused imaging. The scanning of the trapped particle is accomplished through a nano positioning stage integrated to the trap platform. PMID:26559890

  3. Three-dimensional metamaterials fabricated using Proton Beam Writing

    Energy Technology Data Exchange (ETDEWEB)

    Bettiol, A.A., E-mail: a.bettiol@nus.edu.sg [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Turaga, S.P.; Yan, Y.; Vanga, S.K. [Centre for Ion Beam Applications, Department of Physics, National University of Singapore, 2 Science Dr. 3, Singapore 117542 (Singapore); Chiam, S.Y. [NUS High School for Maths and Science, 20 Clementi Avenue 1, Singapore 129957 (Singapore)

    2013-07-01

    Proton Beam Writing (PBW) is a direct write lithographic technique that has recently been applied to the fabrication of three dimensional metamaterials. In this work, we show that the unique capabilities of PBW, namely the ability to fabricate arrays of high resolution, high aspect ratio microstructures in polymer or replicated into metal, is well suited to metamaterials research. We have also developed a novel method for selectively electroless plating silver directly onto polymer structures that were fabricated using PBW. This method opens up new avenues for utilizing PBW for making metamaterials and other sub-wavelength metallic structures. Several potential applications of three dimensional metamaterials fabricated using PBW are discussed, including sensing and negative refractive index materials.

  4. Three-dimensional passive sensing photon counting for object classification

    Science.gov (United States)

    Yeom, Seokwon; Javidi, Bahram; Watson, Edward

    2007-04-01

    In this keynote address, we address three-dimensional (3D) distortion-tolerant object recognition using photon-counting integral imaging (II). A photon-counting linear discriminant analysis (LDA) is discussed for classification of photon-limited images. We develop a compact distortion-tolerant recognition system based on the multiple-perspective imaging of II. Experimental and simulation results have shown that a low level of photons is sufficient to classify out-of-plane rotated objects.

  5. Three-dimensional discrete ordinates reactor assembly calculations on GPUs

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Thomas M [ORNL; Joubert, Wayne [ORNL; Hamilton, Steven P [ORNL; Johnson, Seth R [ORNL; Turner, John A [ORNL; Davidson, Gregory G [ORNL; Pandya, Tara M [ORNL

    2015-01-01

    In this paper we describe and demonstrate a discrete ordinates sweep algorithm on GPUs. This sweep algorithm is nested within a multilevel comunication-based decomposition based on energy. We demonstrated the effectiveness of this algorithm on detailed three-dimensional critical experiments and PWR lattice problems. For these problems we show improvement factors of 4 6 over conventional communication-based, CPU-only sweeps. These sweep kernel speedups resulted in a factor of 2 total time-to-solution improvement.

  6. Three-dimensional, computer simulated navigation in endoscopic neurosurgery

    Directory of Open Access Journals (Sweden)

    Roberta K. Sefcik, BHA

    2017-06-01

    Conclusion: Three-dimensional, frameless neuronavigation systems are useful in endoscopic neurosurgery to assist in the pre-operative planning of potential trajectories and to help localize the pathology of interest. Neuronavigation appears to be accurate to <1–2 mm without issues related to brain shift. Further work is necessary in the investigation of the effect of neuronavigation on operative time, cost, and patient-centered outcomes.

  7. Existence of a new three-dimensional chaotic attractor

    International Nuclear Information System (INIS)

    Wang Jiezhi; Chen Zengqiang; Yuan Zhuzhi

    2009-01-01

    In this paper, one heteroclinic orbit of a new three-dimensional continuous autonomous chaotic system, whose chaotic attractor belongs to the conjugate Lue attractor, is found. The series expression of the heteroclinic orbit of Shil'nikov type is derived by using the undetermined coefficient method. The uniform convergence of the precise series expansions of this heteroclinic orbits is proved. According to the Shil'nikov theorem, this system clearly has Smale horseshoes and the horseshoe chaos.

  8. Heat engine in the three-dimensional spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Mo, Jie-Xiong [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Liang, Feng [Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Li, Gu-Qiang [Institute of Theoretical Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China); Department of Physics, Lingnan Normal University,Zhanjiang, 524048, Guangdong (China)

    2017-03-02

    We define a kind of heat engine via three-dimensional charged BTZ black holes. This case is quite subtle and needs to be more careful. The heat flow along the isochores does not equal to zero since the specific heat C{sub V}≠0 and this point completely differs from the cases discussed before whose isochores and adiabats are identical. So one cannot simply apply the paradigm in the former literatures. However, if one introduces a new thermodynamic parameter associated with the renormalization length scale, the above problem can be solved. We obtain the analytical efficiency expression of the three-dimensional charged BTZ black hole heat engine for two different schemes. Moreover, we double check with the exact formula. Our result presents the first specific example for the sound correctness of the exact efficiency formula. We argue that the three-dimensional charged BTZ black hole can be viewed as a toy model for further investigation of holographic heat engine. Furthermore, we compare our result with that of the Carnot cycle and extend the former result to three-dimensional spacetime. In this sense, the result in this paper would be complementary to those obtained in four-dimensional spacetime or ever higher. Last but not the least, the heat engine efficiency discussed in this paper may serve as a criterion to discriminate the two thermodynamic approaches introduced in ref. https://www.doi.org/10.1103/PhysRevD.92.124069 and our result seems to support the approach which introduces a new thermodynamic parameter R=r{sub 0}.

  9. Three-dimensional echocardiographic assessment of atrial septal defects

    Directory of Open Access Journals (Sweden)

    Charles German

    2015-01-01

    Full Text Available Echocardiography provides a useful tool in the diagnosis of many congenital heart diseases, including atrial septal defects, and aids in further delineating treatment options. Although two-dimensional echocardiography has been the standard of care in this regard, technological advancements have made three-dimensional echocardiography possible, and the images obtained in this new imaging modality are able to accurately portray the morphology, location, dimensions, and dynamic changes of defects and many other heart structures during the cardiac cycle.

  10. Birkhoff's theorem for three-dimensional AdS gravity

    International Nuclear Information System (INIS)

    Ayon-Beato, Eloy; Martinez, Cristian; Zanelli, Jorge

    2004-01-01

    All three-dimensional matter-free space-times with negative cosmological constant, compatible with cyclic symmetry, are identified. The only cyclic solutions are the 2+1 (BTZ) black hole with SO(2)xR isometry, and the self-dual Coussaert-Henneaux space-times, with isometry groups SO(2)xSO(2,1) or SO(2)xSO(2)

  11. Three-dimensional CT of the pediatric spine

    International Nuclear Information System (INIS)

    Starshak, R.J.; Crawford, C.R.; Waisman, R.C.; Sty, J.R.

    1987-01-01

    CT of the spine has been shown to be useful in evaluating congenital, neoplastic, inflammatory, and traumatic lesions. Any portion of the neural arch may be involved by these disease processes. The complex nature of the spinal column can make evaluation of these abnormalities difficult on axial CT. This is especially true if the spine is distorted by scoliosis, kyphosis, or lordosis. This exhibit illustrates the advantages and drawbacks of three-dimensional CT reconstructed images of spinal abnormalities in children

  12. Environmental, Transient, Three-Dimensional, Hydrothermal, Mass Transport Code - FLESCOT

    Energy Technology Data Exchange (ETDEWEB)

    Onishi, Yasuo [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Bao, Jie [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Glass, Kevin A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Eyler, L. L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Okumura, Masahiko [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-03-28

    The purpose of the project was to modify and apply the transient, three-dimensional FLESCOT code to be able to effectively simulate cesium behavior in Fukushima lakes/dam reservoirs, river mouths, and coastal areas. The ultimate objective of the FLESCOT simulation is to predict future changes of cesium accumulation in Fukushima area reservoirs and costal water. These evaluation results will assist ongoing and future environmental remediation activities and policies in a systematic and comprehensive manner.

  13. Study of three-dimensional effects on vortex breakdown

    Science.gov (United States)

    Salas, M. D.; Kuruvila, G.

    1988-01-01

    The incompressible axisymmetric steady Navier-Stokes equations in primitive variables are used to simulate vortex breakdown. The equations, discretized using a second-order, central-difference scheme, are linearized and then solved using an exact LU decomposition, Gaussian elimination, and Newton iteration. Solutions are presented for Reynolds numbers, based on vortex-core radius, as high as 1500. An attempt to study the stability of the axisymmetric solutions against three-dimensional perturbations is discussed.

  14. Three-dimensional massive gravity and the bigravity black hole

    International Nuclear Information System (INIS)

    Banados, Maximo; Theisen, Stefan

    2009-01-01

    We study three-dimensional massive gravity formulated as a theory with two dynamical metrics, like the f-g theories of Isham-Salam and Strathdee. The action is parity preserving and has no higher derivative terms. The spectrum contains a single massive graviton. This theory has several features discussed recently in TMG and NMG. We find warped black holes, a critical point, and generalized Brown-Henneaux boundary conditions.

  15. Spinorial characterizations of surfaces into three-dimensional homogeneous manifolds

    Science.gov (United States)

    Roth, Julien

    2010-06-01

    We give spinorial characterizations of isometrically immersed surfaces into three-dimensional homogeneous manifolds with four-dimensional isometry group in terms of the existence of a particular spinor field. This generalizes works by Friedrich for R3 and Morel for S3 and H3. The main argument is the interpretation of the energy-momentum tensor of such a spinor field as the second fundamental form up to a tensor depending on the structure of the ambient space.

  16. Three-dimensional harmonic control of a nuclear reactor

    International Nuclear Information System (INIS)

    Potapenko, P.T.

    1989-01-01

    Algorithms for neutron flux control based on harmonic three-dimensional core are considered. The essence of the considered approach includes determination of harmonics amplitudes by signals self-powered detectors placed in reactor channels and reconstruction of neutron field distribution over the reactor core volume using the data obtained. Neutron field harmonic control is shown to be reduced to independent measurement and calculation of height harmonics in channels using techniques developed for channel power control

  17. Three-dimensional wound measurements for monitoring wound healing

    DEFF Research Database (Denmark)

    Bisgaard Jørgensen, Line; Møller Jeppesen, Sune; Halekoh, Ulrich

    Telemedicine is increasingly used for monitoring wound healing. Three-dimensional (3D) measurement methods enable clinicians to assess wound healing with respect to all dimensions. However, the currently available methods are inaccurate, costly or complicated to use. To address these issues, a 3D......-WAM camera was developed. This camera is able to measure wound size (2D area, 3D area, perimeter and volume) and to assess wound characteristics....

  18. Three-dimensional charge transport in organic semiconductor single crystals.

    Science.gov (United States)

    He, Tao; Zhang, Xiying; Jia, Jiong; Li, Yexin; Tao, Xutang

    2012-04-24

    Three-dimensional charge transport anisotropy in organic semiconductor single crystals - both plates and rods (above and below, respectively, in the figure) - is measured in well-performing organic field-effect transistors for the first time. The results provide an excellent model for molecular design and device preparation that leads to good performance. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Simulating Photons and Plasmons in a Three-dimensional Lattice

    International Nuclear Information System (INIS)

    Pletzer, A.; Shvets, G.

    2002-01-01

    Three-dimensional metallic photonic structures are studied using a newly developed mixed finite element-finite difference (FE-FD) code, Curly3d. The code solves the vector Helmholtz equation as an eigenvalue problem in the unit cell of a triply periodic lattice composed of conductors and/or dielectrics. The mixed FE-FD discretization scheme ensures rapid numerical convergence of the eigenvalue and allows the code to run at low resolution. Plasmon and photonic band structure calculations are presented

  20. A three-dimensional nodal neutron kinetics capability for relaps

    International Nuclear Information System (INIS)

    Judd, J.L.; Weaver, W.L.

    1996-01-01

    The incorporation of a three-dimensional neutron kinetics capability into the DOE version of the RELAP5/MOD3.2 reactor safety code is discussed. A brief discussion of the kinetics method is given along with a discussion of the cross section parameterization models available in RELAP5/MOD3.2. The RELAP5/MOD3.2 code is then used to perform calculations of the NEACRP rod ejection and rod withdrawal benchmarks, and results are presented

  1. Three-dimensional friction measurement during hip simulation.

    Directory of Open Access Journals (Sweden)

    Robert Sonntag

    Full Text Available Wear of total hip replacements has been the focus of many studies. However, frictional effects, such as high loading on intramodular connections or the interface to the bone, as well as friction associated squeaking have recently increased interest about the amount of friction that is generated during daily activities. The aim of this study was thus to establish and validate a three-dimensional friction setup under standardized conditions.A standard hip simulator was modified to allow for high precision measurements of small frictional effects in the hip during three-dimensional hip articulation. The setup was verified by an ideal hydrostatic bearing and validated with a static-load physical pendulum and an extension-flexion rotation with a dynamic load profile. Additionally, a pendulum model was proposed for screening measurement of frictional effects based on the damping behavior of the angular oscillation without the need for any force/moment transducer. Finally, three-dimensional friction measurements have been realized for ceramic-on-polyethylene bearings of three different sizes (28, 36 and 40 mm.A precision of less than 0.2 Nm during three-dimensional friction measurements was reported, while increased frictional torque (resultant as well as taper torque was measured for larger head diameters. These effects have been confirmed by simple pendulum tests and the theoretical model. A comparison with current literature about friction measurements is presented.This investigation of friction is able to provide more information about a field that has been dominated by the reduction of wear. It should be considered in future pre-clinical testing protocols given by international organizations of standardization.

  2. Three-Dimensional Computer Graphics Brain-Mapping Project

    Science.gov (United States)

    1988-03-24

    1975-76, one of these brains was hand digitized. It was then reconstructed three dimensionally, using an Evans and Sutherland Picture System 2. This...Yakovlev Collection, we use the Evans and Sutherland Picture System 2 which we have been employing for this purpose for a dozen years. Its virtue is...careful, experimentally designed new protocol (See Figure 20). Most of these heads were imaged with Computed Tomography, thanks to Clint Stiles of Picker

  3. Three-dimensional TDHF calculation for reactions of unstable nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ka-Hae; Otsuka, Takaharu [Tokyo Univ. (Japan). Dept. of Physics; Bonche, P.

    1998-07-01

    The fusion is studied for reactions between a stable and an unstable nuclei with neutron skin. The reactions {sup 16,28}O+{sup 40}Ca and {sup 16}O+{sup 16,28}O are taken as examples, and the three-dimensional time-dependent Hartree-Fock method with the full Skyrme interaction is used. It is confirmed that the fusion cross section in low-energy region is sensitive to the interaction used in the calculation. (author)

  4. Three Dimensional Steady Subsonic Euler Flows in Bounded Nozzles

    OpenAIRE

    Chen, Chao; Xie, Chunjing

    2013-01-01

    In this paper, we study the existence and uniqueness of three dimensional steady Euler flows in rectangular nozzles when prescribing normal component of momentum at both the entrance and exit. If, in addition, the normal component of the voriticity and the variation of Bernoulli's function at the exit are both zero, then there exists a unique subsonic potential flow when the magnitude of the normal component of the momentum is less than a critical number. As the magnitude of the normal compon...

  5. Analysis of the three dimensional flow in a turbine scroll

    Science.gov (United States)

    Hamed, A.; Baskharone, E.

    1979-01-01

    The present analysis describes the three-dimensional compressible inviscid flow in the scroll and the vaneless nozzle of a radial inflow turbine. The solution to this flow field, which is further complicated by the geometrical shape of the boundaries, is obtained using the finite element method. Symmetric and nonsymmetric scroll cross sectional geometries are investigated to determine their effect on the general flow field and on the exit flow conditions.

  6. Accuracy of three-dimensional printing for manufacturing replica teeth

    OpenAIRE

    Lee, Keun-Young; Cho, Jin-Woo; Chang, Na-Young; Chae, Jong-Moon; Kang, Kyung-Hwa; Kim, Sang-Cheol; Cho, Jin-Hyoung

    2015-01-01

    Objective Three-dimensional (3D) printing is a recent technological development that may play a significant role in orthodontic diagnosis and treatment. It can be used to fabricate skull models or study models, as well as to make replica teeth in autotransplantation or tooth impaction cases. The aim of this study was to evaluate the accuracy of fabrication of replica teeth made by two types of 3D printing technologies. Methods Fifty extracted molar teeth were selected as samples. They were sc...

  7. Is a three-dimensional-printed tooth filling possible?

    OpenAIRE

    Muhammet Kerim Ayar

    2016-01-01

    Introduction: Three-dimensional (3-D) printing is seen as an innovative production process in many fields of dentistry and medicine. But implantation of this novel production process into the treatment of decayed teeth in dentistry remains lacking. Destruction of dental tissues as a result of dental caries is generally treated with dental resin composite fillings. However, a 3-D-printed tooth filling approach, which could be an alternative to traditional approaches, has a potential to reduce ...

  8. Predicting transition in two- and three-dimensional separated flows

    International Nuclear Information System (INIS)

    Cutrone, L.; De Palma, P.; Pascazio, G.; Napolitano, M.

    2008-01-01

    This paper is concerned with the numerical prediction of two- and three-dimensional transitional separated flows of turbomachinery interest. The recently proposed single-point transition model based on the use of a laminar kinetic energy transport equation is considered, insofar as it does not require to evaluate any integral parameter, such as boundary-layer thickness, and is thus directly applicable to three-dimensional flows. A well established model, combining a transition-onset correlation with an intermittency transport equation, is also used for comparison. Both models are implemented within a Reynolds-averaged Navier-Stokes solver employing a low-Reynolds-number k-ω turbulence model. The performance of the transition models have been evaluated and tested versus well-documented incompressible flows past a flat plate with semi-circular leading edge, namely: tests T3L2, T3L3, T3L5, and T3LA1 of ERCOFTAC, with different Reynolds numbers and free-stream conditions, the last one being characterized by a non-zero pressure gradient. In all computations, the first model has proven as adequate as or superior to the second one and has been then applied with success to two more complex test cases, for which detailed experimental data are available in the literature, namely: the two- and three-dimensional flows through the T106 linear turbine cascade

  9. Three-dimensional features on oscillating microbubbles streaming flows

    Science.gov (United States)

    Rossi, Massimiliano; Marin, Alvaro G.; Wang, Cheng; Hilgenfeldt, Sascha; Kähler, Christian J.

    2013-11-01

    Ultrasound-driven oscillating micro-bubbles have been used as active actuators in microfluidic devices to perform manifold tasks such as mixing, sorting and manipulation of microparticles. A common configuration consists in side-bubbles, created by trapping air pockets in blind channels perpendicular to the main channel direction. This configuration results in bubbles with a semi-cylindrical shape that creates a streaming flow generally considered quasi two-dimensional. However, recent experiments performed with three-dimensional velocimetry methods have shown how microparticles can present significant three-dimensional trajectories, especially in regions close to the bubble interface. Several reasons will be discussed such as boundary effects of the bottom/top wall, deformation of the bubble interface leading to more complex vibrational modes, or bubble-particle interactions. In the present investigation, precise measurements of particle trajectories close to the bubble interface will be performed by means of 3D Astigmatic Particle Tracking Velocimetry. The results will allow us to characterize quantitatively the three-dimensional features of the streaming flow and to estimate its implications in practical applications as particle trapping, sorting or mixing.

  10. Comparison of two three-dimensional cephalometric analysis computer software.

    Science.gov (United States)

    Sawchuk, Dena; Alhadlaq, Adel; Alkhadra, Thamer; Carlyle, Terry D; Kusnoto, Budi; El-Bialy, Tarek

    2014-10-01

    Three-dimensional cephalometric analyses are getting more attraction in orthodontics. The aim of this study was to compare two softwares to evaluate three-dimensional cephalometric analyses of orthodontic treatment outcomes. Twenty cone beam computed tomography images were obtained using i-CAT(®) imaging system from patient's records as part of their regular orthodontic records. The images were analyzed using InVivoDental5.0 (Anatomage Inc.) and 3DCeph™ (University of Illinois at Chicago, Chicago, IL, USA) software. Before and after orthodontic treatments data were analyzed using t-test. Reliability test using interclass correlation coefficient was stronger for InVivoDental5.0 (0.83-0.98) compared with 3DCeph™ (0.51-0.90). Paired t-test comparison of the two softwares shows no statistical significant difference in the measurements made in the two softwares. InVivoDental5.0 measurements are more reproducible and user friendly when compared to 3DCeph™. No statistical difference between the two softwares in linear or angular measurements. 3DCeph™ is more time-consuming in performing three-dimensional analysis compared with InVivoDental5.0.

  11. Supersymmetric quantum mechanics in three-dimensional space, 1

    International Nuclear Information System (INIS)

    Ui, Haruo

    1984-01-01

    As a direct generalization of the model of supersymmetric quantum mechanics by Witten, which describes the motion of a spin one-half particle in the one-dimensional space, we construct a model of the supersymmetric quantum mechanics in the three-dimensional space, which describes the motion of a spin one-half particle in central and spin-orbit potentials in the context of the nonrelativistic quantum mechanics. With the simplest choice of the (super) potential, this model is shown to reduce to the model of the harmonic oscillator plus constant spin-orbit potential of unit strength of both positive and negative signs, which was studied in detail in our recent paper in connection with ''accidental degeneracy'' as well as the ''graded groups''. This simplest model is discussed in some detail as an example of the three-dimensional supersymmetric quantum mechanical system, where the supersymmetry is an exact symmetry of the system. More general choice of a polynomial superpotential is also discussed. It is shown that the supersymmetry cannot be spontaneously broken for any polynomial superpotential in our three-dimensional model; this result is contrasted to the corresponding one in the one-dimensional model. (author)

  12. Development of a Three-dimensional Surgical Navigation System with Magnetic Resonance Angiography and a Three-dimensional Printer for Robot-assisted Radical Prostatectomy.

    Science.gov (United States)

    Jomoto, Wataru; Tanooka, Masao; Doi, Hiroshi; Kikuchi, Keisuke; Mitsuie, Chiemi; Yamada, Yusuke; Suzuki, Toru; Yamano, Toshiko; Ishikura, Reiichi; Kotoura, Noriko; Yamamoto, Shingo

    2018-01-02

    We sought to develop a surgical navigation system using magnetic resonance angiography (MRA) and a three-dimensional (3D) printer for robot-assisted radical prostatectomy (RARP). Six patients with pathologically proven localized prostate cancer were prospectively enrolled in this study. Prostate magnetic resonance imaging (MRI), consisting of T2-weighted sampling perfection with application-optimized contrasts using different flip-angle evolutions (SPACE) and true fast imaging with steady-state precession (true FISP), reconstructed by volume rendering, was followed by dynamic contrast-enhanced MRA performed with a volumetric interpolated breath-hold examination (VIBE) during intravenous bolus injection of gadobutrol. Images of arterial and venous phases were acquired over approximately 210 seconds. Selected images were sent to a workstation for generation of 3D volume-rendered images and standard triangulated language (STL) files for 3D print construction. The neurovascular bundles (NVBs) were found in sequence on non-contrast images. Accessory pudendal arteries (APAs) were found in all cases in the arterial phase of contrast enhancement but were ill-defined on non-contrast enhanced MRA. Dynamic contrast-enhanced MRA helped to detect APAs, suggesting that this 3D system using MRI will be useful in RARP.

  13. Integration of Computed Tomography and Three-Dimensional Echocardiography for Hybrid Three-Dimensional Printing in Congenital Heart Disease.

    Science.gov (United States)

    Gosnell, Jordan; Pietila, Todd; Samuel, Bennett P; Kurup, Harikrishnan K N; Haw, Marcus P; Vettukattil, Joseph J

    2016-12-01

    Three-dimensional (3D) printing is an emerging technology aiding diagnostics, education, and interventional, and surgical planning in congenital heart disease (CHD). Three-dimensional printing has been derived from computed tomography, cardiac magnetic resonance, and 3D echocardiography. However, individually the imaging modalities may not provide adequate visualization of complex CHD. The integration of the strengths of two or more imaging modalities has the potential to enhance visualization of cardiac pathomorphology. We describe the feasibility of hybrid 3D printing from two imaging modalities in a patient with congenitally corrected transposition of the great arteries (L-TGA). Hybrid 3D printing may be useful as an additional tool for cardiologists and cardiothoracic surgeons in planning interventions in children and adults with CHD.

  14. Phase Diagrams of Three-Dimensional Anderson and Quantum Percolation Models Using Deep Three-Dimensional Convolutional Neural Network

    Science.gov (United States)

    Mano, Tomohiro; Ohtsuki, Tomi

    2017-11-01

    The three-dimensional Anderson model is a well-studied model of disordered electron systems that shows the delocalization-localization transition. As in our previous papers on two- and three-dimensional (2D, 3D) quantum phase transitions [J. Phys. Soc. Jpn. 85, 123706 (2016), 86, 044708 (2017)], we used an image recognition algorithm based on a multilayered convolutional neural network. However, in contrast to previous papers in which 2D image recognition was used, we applied 3D image recognition to analyze entire 3D wave functions. We show that a full phase diagram of the disorder-energy plane is obtained once the 3D convolutional neural network has been trained at the band center. We further demonstrate that the full phase diagram for 3D quantum bond and site percolations can be drawn by training the 3D Anderson model at the band center.

  15. Three-dimensional analysis of cellular microstructures by computer simulation

    International Nuclear Information System (INIS)

    Hanson, K.; Morris, J.W. Jr.

    1977-06-01

    For microstructures of the ''cellular'' type (isotropic growth from a distribution of nuclei which form simultaneously), it is possible to construct an efficient code which will completely analyze the microstructure in three dimensions. Such a computer code for creating and storing the connected graph was constructed

  16. On some three-dimensional problems of piezoelectricity | Saha ...

    African Journals Online (AJOL)

    The problem of an elliptical crack embedded in an unbounded transversely isotropic piezoelectric medium and subjected to remote normal loading is considered first. The integral equation method developed by Roy and his coworkers has been applied suitably with proper modifications to solve the problem. The method ...

  17. Three-dimensional labeling program for elucidation of the geometric properties of biological particles in three-dimensional space.

    Science.gov (United States)

    Nomura, A; Yamazaki, Y; Tsuji, T; Kawasaki, Y; Tanaka, S

    1996-09-15

    For all biological particles such as cells or cellular organelles, there are three-dimensional coordinates representing the centroid or center of gravity. These coordinates and other numerical parameters such as volume, fluorescence intensity, surface area, and shape are referred to in this paper as geometric properties, which may provide critical information for the clarification of in situ mechanisms of molecular and cellular functions in living organisms. We have established a method for the elucidation of these properties, designated the three-dimensional labeling program (3DLP). Algorithms of 3DLP are so simple that this method can be carried out through the use of software combinations in image analysis on a personal computer. To evaluate 3DLP, it was applied to a 32-cell-stage sea urchin embryo, double stained with FITC for cellular protein of blastomeres and propidium iodide for nuclear DNA. A stack of optical serial section images was obtained by confocal laser scanning microscopy. The method was found effective for determining geometric properties and should prove applicable to the study of many different kinds of biological particles in three-dimensional space.

  18. New criteria for isotropic and textured metals

    Science.gov (United States)

    Cazacu, Oana

    2018-05-01

    In this paper a isotropic criterion expressed in terms of both invariants of the stress deviator, J2 and J3 is proposed. This criterion involves a unique parameter, α, which depends only on the ratio between the yield stresses in uniaxial tension and pure shear. If this parameter is zero, the von Mises yield criterion is recovered; if a is positive the yield surface is interior to the von Mises yield surface whereas when a is negative, the new yield surface is exterior to it. Comparison with polycrystalline calculations using Taylor-Bishop-Hill model [1] for randomly oriented face-centered (FCC) polycrystalline metallic materials show that this new criterion captures well the numerical yield points. Furthermore, the criterion reproduces well yielding under combined tension-shear loadings for a variety of isotropic materials. An extension of this isotropic yield criterion such as to account for orthotropy in yielding is developed using the generalized invariants approach of Cazacu and Barlat [2]. This new orthotropic criterion is general and applicable to three-dimensional stress states. The procedure for the identification of the material parameters is outlined. Illustration of the predictive capabilities of the new orthotropic is demonstrated through comparison between the model predictions and data on aluminum sheet samples.

  19. MRI

    DEFF Research Database (Denmark)

    Schroeter, Aileen; Rudin, Markus; Gianolio, Eliana

    2017-01-01

    This chapter discusses principles of nuclear magnetic resonance (NMR) and MRI followed by a survey on the major classes of MRI contrast agents (CA), their modes of action, and some of the most significative applications. The two more established classes of MRI-CA are represented by paramagnetic...... been attained that markedly increase the number and typology of systems with CEST properties. Currently much attention is also devoted to hyperpolarized molecules that display a sensitivity enhancement sufficient for their direct exploitation for the formation of the MR image. A real breakthrough...

  20. MRI

    Science.gov (United States)

    ... the room. Pins, hairpins, metal zippers, and similar metallic items can distort the images. Removable dental work ... an MRI can cause heart pacemakers and other implants not to work as well. The magnets can ...

  1. Asymmetric three-dimensional topography over mantle plumes.

    Science.gov (United States)

    Burov, Evgueni; Gerya, Taras

    2014-09-04

    The role of mantle-lithosphere interactions in shaping surface topography has long been debated. In general, it is supposed that mantle plumes and vertical mantle flows result in axisymmetric, long-wavelength topography, which strongly differs from the generally asymmetric short-wavelength topography created by intraplate tectonic forces. However, identification of mantle-induced topography is difficult, especially in the continents. It can be argued therefore that complex brittle-ductile rheology and stratification of the continental lithosphere result in short-wavelength modulation and localization of deformation induced by mantle flow. This deformation should also be affected by far-field stresses and, hence, interplay with the 'tectonic' topography (for example, in the 'active/passive' rifting scenario). Testing these ideas requires fully coupled three-dimensional numerical modelling of mantle-lithosphere interactions, which so far has not been possible owing to the conceptual and technical limitations of earlier approaches. Here we present new, ultra-high-resolution, three-dimensional numerical experiments on topography over mantle plumes, incorporating a weakly pre-stressed (ultra-slow spreading), rheologically realistic lithosphere. The results show complex surface evolution, which is very different from the smooth, radially symmetric patterns usually assumed as the canonical surface signature of mantle upwellings. In particular, the topography exhibits strongly asymmetric, small-scale, three-dimensional features, which include narrow and wide rifts, flexural flank uplifts and fault structures. This suggests a dominant role for continental rheological structure and intra-plate stresses in controlling dynamic topography, mantle-lithosphere interactions, and continental break-up processes above mantle plumes.

  2. Regularization of DT-MRI Using 3D Median Filtering Methods

    Directory of Open Access Journals (Sweden)

    Soondong Kwon

    2014-01-01

    Full Text Available DT-MRI (diffusion tensor magnetic resonance imaging tractography is a method to determine the architecture of axonal fibers in the central nervous system by computing the direction of the principal eigenvectors obtained from tensor matrix, which is different from the conventional isotropic MRI. Tractography based on DT-MRI is known to need many computations and is highly sensitive to noise. Hence, adequate regularization methods, such as image processing techniques, are in demand. Among many regularization methods we are interested in the median filtering method. In this paper, we extended two-dimensional median filters already developed to three-dimensional median filters. We compared four median filtering methods which are two-dimensional simple median method (SM2D, two-dimensional successive Fermat method (SF2D, three-dimensional simple median method (SM3D, and three-dimensional successive Fermat method (SF3D. Three kinds of synthetic data with different altitude angles from axial slices and one kind of human data from MR scanner are considered for numerical implementation by the four filtering methods.

  3. Three-dimensional illumination procedure for photodynamic therapy of dermatology

    Science.gov (United States)

    Hu, Xiao-ming; Zhang, Feng-juan; Dong, Fei; Zhou, Ya

    2014-09-01

    Light dosimetry is an important parameter that affects the efficacy of photodynamic therapy (PDT). However, the irregular morphologies of lesions complicate lesion segmentation and light irradiance adjustment. Therefore, this study developed an illumination demo system comprising a camera, a digital projector, and a computing unit to solve these problems. A three-dimensional model of a lesion was reconstructed using the developed system. Hierarchical segmentation was achieved with the superpixel algorithm. The expected light dosimetry on the targeted lesion was achieved with the proposed illumination procedure. Accurate control and optimization of light delivery can improve the efficacy of PDT.

  4. Optical Forging of Graphene into Three-Dimensional Shapes.

    Science.gov (United States)

    Johansson, Andreas; Myllyperkiö, Pasi; Koskinen, Pekka; Aumanen, Jukka; Koivistoinen, Juha; Tsai, Hung-Chieh; Chen, Chia-Hao; Chang, Lo-Yueh; Hiltunen, Vesa-Matti; Manninen, Jyrki J; Woon, Wei Yen; Pettersson, Mika

    2017-10-11

    Atomically thin materials, such as graphene, are the ultimate building blocks for nanoscale devices. But although their synthesis and handling today are routine, all efforts thus far have been restricted to flat natural geometries, since the means to control their three-dimensional (3D) morphology has remained elusive. Here we show that, just as a blacksmith uses a hammer to forge a metal sheet into 3D shapes, a pulsed laser beam can forge a graphene sheet into controlled 3D shapes in the nanoscale. The forging mechanism is based on laser-induced local expansion of graphene, as confirmed by computer simulations using thin sheet elasticity theory.

  5. Development of three dimensional ocean current model for coastal region

    International Nuclear Information System (INIS)

    Kobayashi, Takuya

    1999-12-01

    In order to study the migration behavior of radionuclides released into a coastal region around Japan, Princeton Ocean Model (POM) was introduced. This three-dimensional ocean current model was modified to be applied for oceanic simulations around Japan. This report describes the governing equations, numerical methods and model improvements. In addition, database system which is utilized for calculations and visualization system for graphical outputs are also described. Model simulation was carried out at off the area of Shimokita. Aomori-ken, Japan to investigate the effects of the boundary conditions on simulated results. (author)

  6. Three-dimensional fractional topological insulators in coupled Rashba layers

    Science.gov (United States)

    Volpez, Yanick; Loss, Daniel; Klinovaja, Jelena

    2017-08-01

    We propose a model of three-dimensional topological insulators consisting of weakly coupled electron- and hole-gas layers with Rashba spin-orbit interaction stacked along a given axis. We show that in the presence of strong electron-electron interactions the system realizes a fractional strong topological insulator, where the rotational symmetry and condensation energy arguments still allow us to treat the problem as quasi-one-dimensional with bosonization techniques. We also show that if Rashba and Dresselhaus spin-orbit interaction terms are equally strong, by doping the system with magnetic impurities, one can bring it into the Weyl semimetal phase.

  7. Three-dimensional problems in the theory of cracks

    International Nuclear Information System (INIS)

    Panasyuk, V.V.; Andrejkiv, A.E.; Stadnik, M.M.

    1979-01-01

    Review of the main mechanical conceptions and mathematic methods, used in solving of spatial problems of the theory of cracks is given. At that, cases of effects upon a body of force static and cyclic and geometrically variable temperature fields are considered. The main calculation models of the theory of cracks are characterized in detail. Other models, derived from these ones and used in solving the above problems are also mentioned. Analysis and synthesis of the most general mathematic methods of solving three-dimensional problems of the theory of cracks are made. Besides precise methods, approximate ones are also presented, being efficient enough in engineering practice

  8. Impurity states in two - and three-dimensional disordered systems

    International Nuclear Information System (INIS)

    Silva, A.F. da; Fabbri, M.

    1984-01-01

    We investigate the microscopic structure of the impurity states in two-and three-dimensional (2D and 3d) disordered systems. A cluster model is outlined for the donor impurity density of states (DIDS) of doped semiconductors. It is shown that the impurity states are very sensitive to a change in the dimensionality of the system, i.e from 3D to 2D system. It is found that all eigenstates become localized in 2D disordered system for a large range of concentration. (Author) [pt

  9. Three-Dimensional Numerical Simulation to Mud Turbine for LWD

    Science.gov (United States)

    Yao, Xiaojiang; Dong, Jingxin; Shang, Jie; Zhang, Guanqi

    Hydraulic performance analysis was discussed for a type of turbine on generator used for LWD. The simulation models were built by CFD analysis software FINE/Turbo, and full three-dimensional numerical simulation was carried out for impeller group. The hydraulic parameter such as power, speed and pressure drop, were calculated in two kinds of medium water and mud. Experiment was built in water environment. The error of numerical simulation was less than 6%, verified by experiment. Based on this rationalization proposals would be given to choice appropriate impellers, and the rationalization of methods would be explored.

  10. Surgical accuracy of three-dimensional virtual planning

    DEFF Research Database (Denmark)

    Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

    2016-01-01

    This retrospective study evaluated the precision and positional accuracy of different orthognathic procedures following virtual surgical planning in 30 patients. To date, no studies of three-dimensional virtual surgical planning have evaluated the influence of segmentation on positional accuracy...... and transverse expansion. Furthermore, only a few have evaluated the precision and accuracy of genioplasty in placement of the chin segment. The virtual surgical plan was compared with the postsurgical outcome by using three linear and three rotational measurements. The influence of maxillary segmentation...

  11. Recurrence relations in the three-dimensional Ising model

    International Nuclear Information System (INIS)

    Yukhnovskij, I.R.; Kozlovskij, M.P.

    1977-01-01

    Recurrence relations between the coefficients asub(2)sup((i)), asub(4)sup((i)) and Psub(2)sup((i)), Psub(4)sup((i)) which characterize the probabilities of distribution for the three-dimensional Ising model are studied. It is shown that for large arguments z of the Makdonald functions Ksub(ν)(z) the recurrence relations correspond to the known Wilson relations. But near the critical point for small values of the transfer momentum k this limit case does not take place. In the pointed region the argument z tends to zero, and new recurrence relations take place

  12. Evaluation of solar energy over three dimensional objects

    International Nuclear Information System (INIS)

    Serposhan, S.; Yaghoubi, M.

    2002-01-01

    The knowledge of solar irradiation is important in heating and cooling of buildings architectural engineering, various solar energy utilizations, and for any system design exposed to sun radiation. In the present article, simulation is made to predict solar irradiation over any three-dimensional objects. Special consideration is made to evaluate solar radiation intensity distribution over semi-circular roof and domed roofs. For practical applications, hourly and average daily solar radiation distribution for a series of three Heller type huge cooling towers of Fars Power Plant is also determined

  13. Three-dimensional cranio-facial computed tomography

    International Nuclear Information System (INIS)

    Pozzi Muccelli, R.; Stagul, F.; Pozzi Muccelli, F.; Zuiani, C.; Smathers, R.

    1986-01-01

    Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy

  14. Turbulence in Three Dimensional Simulations of Magnetopause Reconnection

    Science.gov (United States)

    Drake, J. F.; Price, L.; Swisdak, M.; Burch, J. L.; Cassak, P.; Dahlin, J. T.; Ergun, R.

    2017-12-01

    We present two- and three-dimensional particle-in-cell simulations of the 16 October 2015 MMS magnetopause reconnection event. While the two-dimensional simulation is laminar, turbulence develops at both the x-line and along the magnetic separatrices in the three-dimensional simulation. This turbulence is electromagnetic in nature, is characterized by a wavevector k given by kρ e ˜(m_e/m_i)0.25 with ρ e the electron Larmor radius, and appears to have the ion pressure gradient as its source of free energy. Taken together, these results suggest the instability is a variant of the lower-hybrid drift instability. The turbulence produces electric field fluctuations in the out-of-plane direction (the direction of the reconnection electric field) with an amplitude of around ± 10 mV/m, which is much greater than the reconnection electric field of around 0.1 mV/m. Such large values of the out-of-plane electric field have been identified in the MMS data. The turbulence in the simulation controls the scale lengths of the density profile and current layers in asymmetric reconnection, driving them closer to √ {ρ eρ_i } than the ρ e or de scalings seen in 2D reconnection simulations, where de is the electron inertial length. The turbulence is strong enough to make the magnetic field around the reconnection island chaotic and produces both anomalous resistivity and anomalous viscosity. Each contribute significantly to breaking the frozen-in condition in the electron diffusion region. The crescent-shaped features in velocity space seen both in MMS observations and in two-dimensional simulations survive, even in the turbulent environment of the three-dimensional system. We compare and contrast these results to a three-dimensional simulation of the 8 December 2015 MMS magnetopause reconnection event in which the reconnecting and out-of-plane guide fields are comparable. LHDI is still present in this event, although its appearance is modified by the presence of the guide

  15. Kaon-nucleon scattering in three-dimensional technique

    International Nuclear Information System (INIS)

    Salam, Agus; Fachruddin, Imam

    2016-01-01

    Kaon-nucleon (KN) scattering is formulated in the three-dimensional (3D) momentum space, in which the basis state is not expanded into partial waves. Based on this basis the Lippmann-Schwinger equation for the T-matrix is evaluated. We obtain as final equation for the T-matrix elements a set of two coupled integral equations in two variables, which are the momentum’s magnitude and the scattering angle. Calculations for the differential cross section and some spin observables are shown, for which we employ a hadrons exchange model with the second order contributions only.

  16. Three-dimensional measurement of a tightly focused laser beam

    Directory of Open Access Journals (Sweden)

    Xiangsheng Xie

    2013-02-01

    Full Text Available The spatial structure of a tightly focused light field is measured with a double knife-edge scanning method. The measurement method is based on the use of a high-quality double knife-edge fabricated from a right-angled silicon fragment mounted on a photodetector. The reconstruction of the three-dimensional structures of tightly focused spots is carried out with both uniform and partially obstructed linearly polarized incident light beams. The optical field distribution is found to deviate substantially from the input beam profile in the tightly focused region, which is in good agreement with the results of numerical simulations.

  17. Photogrammetry: applications of a three-dimensional remote measurement technique

    International Nuclear Information System (INIS)

    Peak, K.

    1988-01-01

    Photogrammetry is defined as the precise art of abstracting measurements from photographic images. Used for many years as a means to produce the world's maps, it has, in recent years, been applied in many engineering environments. The nuclear industry has, in particular, benefitted from the close range applications of photogrammetry. This paper sets out to describe the techniques involved, from the site photography through to the analytical data extraction. It will include a number of examples of where photogrammetry has been used in the nuclear industry as a remote measurement technique, from simple monitoring exercises to the compilation of complex three-dimensional as-built computer models. (author)

  18. Three-dimensional, subsurface imaging synthetic aperture radar

    International Nuclear Information System (INIS)

    Moussally, G.J.

    1994-01-01

    The objective of this applied research and devolpment project is to develop a system known as 3-D SISAR. This sytem consists of a gound penetrating radar with software algorithms designed for detection, location, and identification of buried objects in the underground hazardous waste environments found at US DOE storage sites. Three-dimensional maps can assist the development of remdiation strategies and characterization of the digface during remediation. The system should also be useful for monitoring hydrocarbon-based contaminant migration after remediation. 5 figs

  19. 3D radiation sensors with three dimensional electrodes

    CERN Document Server

    Da Via, Cinzia; Parker, Sherwood

    2018-01-01

    This book covers the technical properties, fabrication details, measurement results and applications of three-dimensional silicon radiation sensors. Such devices are currently used in the ATLAS experiment at the European Centre for Particle Physics (CERN) for particle tracking in high energy physics. They are the radiation hardest devices ever fabricated. They have applications in neutron detection, medical dosimetry and space. Written by the leading names in this field, the book explains to non-experts the essential features of silicon particle detectors, interactions of radiation with matter, radiation damage effects, and micro-fabrication. It also provides an historical view of the above.

  20. Integrating three-dimensional printing and nanotechnology for musculoskeletal regeneration

    Science.gov (United States)

    Nowicki, Margaret; Castro, Nathan J.; Rao, Raj; Plesniak, Michael; Zhang, Lijie Grace

    2017-09-01

    The field of tissue engineering is advancing steadily, partly due to advancements in rapid prototyping technology. Even with increasing focus, successful complex tissue regeneration of vascularized bone, cartilage and the osteochondral interface remains largely illusive. This review examines current three-dimensional printing techniques and their application towards bone, cartilage and osteochondral regeneration. The importance of, and benefit to, nanomaterial integration is also highlighted with recent published examples. Early-stage successes and challenges of recent studies are discussed, with an outlook to future research in the related areas.

  1. Self-assembled three-dimensional chiral colloidal architecture

    Science.gov (United States)

    Ben Zion, Matan Yah; He, Xiaojin; Maass, Corinna C.; Sha, Ruojie; Seeman, Nadrian C.; Chaikin, Paul M.

    2017-11-01

    Although stereochemistry has been a central focus of the molecular sciences since Pasteur, its province has previously been restricted to the nanometric scale. We have programmed the self-assembly of micron-sized colloidal clusters with structural information stemming from a nanometric arrangement. This was done by combining DNA nanotechnology with colloidal science. Using the functional flexibility of DNA origami in conjunction with the structural rigidity of colloidal particles, we demonstrate the parallel self-assembly of three-dimensional microconstructs, evincing highly specific geometry that includes control over position, dihedral angles, and cluster chirality.

  2. Modified Three-Dimensional Multicarrier Optical Prime Codes

    Directory of Open Access Journals (Sweden)

    Rajesh Yadav

    2016-01-01

    Full Text Available We propose a mathematical model for novel three-dimensional multicarrier optical codes in terms of wavelength/time/space based on the prime sequence algorithm. The proposed model has been extensively simulated on MATLAB for prime numbers (P to analyze the performance of code in terms of autocorrelation and cross-correlation. The simulated outcome resembles the mathematical model and gives better results over other methods available in the literature as far as autocorrelation and cross-correlation are concerned. The proposed 3D optical codes are more efficient in terms of cardinality, improved security, and providing quality of services.

  3. ORMEC: a three-dimensional MHD spectral inverse equilibrium code

    International Nuclear Information System (INIS)

    Hirshman, S.P.; Hogan, J.T.

    1986-02-01

    The Oak Ridge Moments Equilibrium Code (ORMEC) is an efficient computer code that has been developed to calculate three-dimensional MHD equilibria using the inverse spectral method. The fixed boundary formulation, which is based on a variational principle for the spectral coefficients (moments) of the cylindrical coordinates R and Z, is described and compared with the finite difference code BETA developed by Bauer, Betancourt, and Garabedian. Calculations for the Heliotron, Wendelstein VIIA, and Advanced Toroidal Facility (ATF) configurations are performed to establish the accuracy and mesh convergence properties for the spectral method. 16 refs., 13 figs

  4. A Three-dimensional Topological Model of Ternary Phase Diagram

    International Nuclear Information System (INIS)

    Mu, Yingxue; Bao, Hong

    2017-01-01

    In order to obtain a visualization of the complex internal structure of ternary phase diagram, the paper realized a three-dimensional topology model of ternary phase diagram with the designed data structure and improved algorithm, under the guidance of relevant theories of computer graphics. The purpose of the model is mainly to analyze the relationship between each phase region of a ternary phase diagram. The model not only obtain isothermal section graph at any temperature, but also extract a particular phase region in which users are interested. (paper)

  5. Wave field restoration using three-dimensional Fourier filtering method.

    Science.gov (United States)

    Kawasaki, T; Takai, Y; Ikuta, T; Shimizu, R

    2001-11-01

    A wave field restoration method in transmission electron microscopy (TEM) was mathematically derived based on a three-dimensional (3D) image formation theory. Wave field restoration using this method together with spherical aberration correction was experimentally confirmed in through-focus images of amorphous tungsten thin film, and the resolution of the reconstructed phase image was successfully improved from the Scherzer resolution limit to the information limit. In an application of this method to a crystalline sample, the surface structure of Au(110) was observed in a profile-imaging mode. The processed phase image showed quantitatively the atomic relaxation of the topmost layer.

  6. Monopole gas in three dimensional SU(2) gluodynamics

    International Nuclear Information System (INIS)

    Chernodub, M.N.; Ishiguro, Katsuya; Suzuki, Tsuneo

    2004-01-01

    We study properties of the Abelian monopoles in the Maximal Abelian projection of the three dimensional pure SU(2) gauge model. We match the lattice monopole dynamics with the continuum Coulomb gas model using a method of blocking from continuum. We obtain the Debye screening length and the monopole density in continuum using numerical results for the density to the (squared) monopole charges and for the monopole action. The monopoles treated within our blocking method provide about 75% contribution to the non-Abelian Debye screening length. We also find that monopoles form a Coulomb plasma which is not dilute. (author)

  7. Quantum tunneling from three-dimensional black holes

    International Nuclear Information System (INIS)

    Ejaz, Asiya; Gohar, H.; Lin, Hai; Saifullah, K.; Yau, Shing-Tung

    2013-01-01

    We study Hawking radiation from three-dimensional black holes. For this purpose the emission of charged scalar and charged fermionic particles is investigated from charged BTZ black holes, with and without rotation. We use the quantum tunneling approach incorporating WKB approximation and spacetime symmetries. Another class of black holes which is asymptotic to a Sol three-manifold has also been investigated. This procedure gives us the tunneling probability of outgoing particles, and we compute the temperature of the radiation for these black holes. We also consider the quantum tunneling of particles from black hole asymptotic to Sol geometry

  8. Three-Dimensional Bone Adaptation of the Proximal Femur

    DEFF Research Database (Denmark)

    Bagge, Mette

    1998-01-01

    The bone remodeling of a three-dimensional model of the proximal femur is considered. The bone adaptation is numerically described as an evolution in time formulated such that the structural change goes in an optimal direction within each time step for the optimal boundary conditions. In the bone...... remodeling scheme is included the memory of past loadings to account for the delay in the bone response to the load changes. In order to get a realistic bone adaptation process, the bone structure at the onset of the remodeling needs to be realistic too. A start design is obtained by structural optimization...

  9. Fate of superconductivity in three-dimensional disordered Luttinger semimetals

    Science.gov (United States)

    Mandal, Ipsita

    2018-05-01

    Superconducting instability can occur in three-dimensional quadratic band crossing semimetals only at a finite coupling strength due to the vanishing of density of states at the quadratic band touching point. Since realistic materials are always disordered to some extent, we study the effect of short-ranged-correlated disorder on this superconducting quantum critical point using a controlled loop-expansion applying dimensional regularization. The renormalization group (RG) scheme allows us to determine the RG flows of the various interaction strengths and shows that disorder destroys the superconducting quantum critical point. In fact, the system exhibits a runaway flow to strong disorder.

  10. Teaching veterinary obstetrics using three-dimensional animation technology.

    Science.gov (United States)

    Scherzer, Jakob; Buchanan, M Flint; Moore, James N; White, Susan L

    2010-01-01

    In this three-year study, test scores for students taught veterinary obstetrics in a classroom setting with either traditional media (photographs, text, and two-dimensional graphical presentations) were compared with those for students taught by incorporating three-dimensional (3D) media (linear animations and interactive QuickTime Virtual Reality models) into the classroom lectures. Incorporation of the 3D animations and interactive models significantly increased students' scores on essay questions designed to assess their comprehension of the subject matter. This approach to education may help to better prepare students for dealing with obstetrical cases during their final clinical year and after graduation.

  11. Nanofluidic structures with complex three-dimensional surfaces

    International Nuclear Information System (INIS)

    Stavis, Samuel M; Gaitan, Michael; Strychalski, Elizabeth A

    2009-01-01

    Nanofluidic devices have typically explored a design space of patterns limited by a single nanoscale structure depth. A method is presented here for fabricating nanofluidic structures with complex three-dimensional (3D) surfaces, utilizing a single layer of grayscale photolithography and standard integrated circuit manufacturing tools. This method is applied to construct nanofluidic devices with numerous (30) structure depths controlled from ∼10 to ∼620 nm with an average standard deviation of 1 cm. A prototype 3D nanofluidic device is demonstrated that implements size exclusion of rigid nanoparticles and variable nanoscale confinement and deformation of biomolecules.

  12. Study of guided modes in three-dimensional composites

    Science.gov (United States)

    Baste, S.; Gerard, A.

    The propagation of elastic waves in a three-dimensional carbon-carbon composite is modeled with a mixed variational method, using the Bloch or Floquet theories and the Hellinger-Reissner function for two independent fields. The model of the equivalent homogeneous material only exists below a cut-off frequency of about 600 kHz. The existence below the cut-off frequency of two guided waves can account for the presence of a slow guided wave on either side of the cut-off frequency. Optical modes are generated at low frequencies, and can attain high velocites (rapid guided modes of 15,000 m/sec).

  13. Coherent states on horospheric three-dimensional Lobachevsky space

    Energy Technology Data Exchange (ETDEWEB)

    Kurochkin, Yu., E-mail: y.kurochkin@ifanbel.bas-net.by; Shoukavy, Dz., E-mail: shoukavy@ifanbel.bas-net.by [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezalezhnasci Ave., Minsk 220072 (Belarus); Rybak, I., E-mail: Ivan.Rybak@astro.up.pt [Institute of Physics, National Academy of Sciences of Belarus, 68 Nezalezhnasci Ave., Minsk 220072 (Belarus); Instituto de Astrofísica e Ciências do Espaço, CAUP, Rua das Estrelas, 4150-762 Porto (Portugal); Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal)

    2016-08-15

    In the paper it is shown that due to separation of variables in the Laplace-Beltrami operator (Hamiltonian of a free quantum particle) in horospheric and quasi-Cartesian coordinates of three dimensional Lobachevsky space, it is possible to introduce standard (“conventional” according to Perelomov [Generalized Coherent States and Their Applications (Springer-Verlag, 1986), p. 320]) coherent states. Some problems (oscillator on horosphere, charged particle in analogy of constant uniform magnetic field) where coherent states are suitable for treating were considered.

  14. Methods for preparation of three-dimensional bodies

    Science.gov (United States)

    Mulligan, Anthony C.; Rigali, Mark J.; Sutaria, Manish P.; Artz, Gregory J.; Gafner, Felix H.; Vaidyanathan, K. Ranji

    2004-09-28

    Processes for mechanically fabricating two and three-dimensional fibrous monolith composites include preparing a fibrous monolith filament from a core composition of a first powder material and a boundary material of a second powder material. The filament includes a first portion of the core composition surrounded by a second portion of the boundary composition. One or more filaments are extruded through a mechanically-controlled deposition nozzle onto a working surface to create a fibrous monolith composite object. The objects may be formed directly from computer models and have complex geometries.

  15. Photonic Paint Developed with Metallic Three-Dimensional Photonic Crystals

    Science.gov (United States)

    Sun, Po; Williams, John D.

    2012-01-01

    This work details the design and simulation of an inconspicuous photonic paint that can be applied onto an object for anticounterfeit and tag, track, and locate (TTL) applications. The paint consists of three-dimensional metallic tilted woodpile photonic crystals embedded into a visible and infrared transparent polymer film, which can be applied to almost any surface. The tilted woodpile photonic crystals are designed with a specific pass band detectable at nearly all incident angles of light. When painted onto a surface, these crystals provide a unique reflective infra-red optical signature that can be easily observed and recorded to verify the location or contents of a package.

  16. Two-and three-dimensional CT reconstruction

    International Nuclear Information System (INIS)

    Fishman, E.K.; Ney, D.R.; Magid, D.

    1990-01-01

    This paper determines the optimal imaging sequence for creating two- and three-dimensional (2D/3D) skeletal reconstructions from CT data. A cadaver femur, a bone phantom, and a surgically created fracture were scanned with varying protocols to determine the optimal protocol for creating 2D/3D images. The scanning protocols used varying section thickness (2, 4, and 8 mm) as well as scan spacing (2, 3, 4 and 8 mm). All images were reconstructed into 2D data sets with a bicubic interpolation and 3D datasets with volumetric rendering. The results were reviewed by two reviewers to determine the quality of images reconstruction

  17. Fuel assembly inspection by three-dimensional neutron radiography

    International Nuclear Information System (INIS)

    Lapinski, N.P.; Reimann, K.J.; Berger, H.

    1979-01-01

    Radiographic inspection of complex objects such as fuel subassemblies often presents problems because superimposition of images at different depths in the object complicates interpretation. One method for obtaining and displaying three-dimensional neutron radiographic images in multiple-film laminagraphy; a series of radiographs generated at different angular orientations are superimposed to provide focussed images of any object plane. In the present work multiple-film neutron laminagraphs were generated using direct and indirect exposure techniques, with neutrons in thermal, epithermal, and fast energy ranges

  18. Three-dimensional laser pulse intensity diagnostic for photoinjectors

    Directory of Open Access Journals (Sweden)

    Heng Li

    2011-11-01

    Full Text Available Minimizing the electron-beam emittance of photoinjectors is an important task for maximizing the brightness of the next-generation x-ray facilities, such as free-electron lasers and energy recovery linacs. Optimally shaped laser pulses can significantly reduce emittance. A reliable diagnostic for the laser pulse intensity is required for this purpose. We demonstrate measurement of three-dimensional spatiotemporal intensity profiles, with spatial resolution of 20  μm and temporal resolution of 130 fs. The capability is illustrated by measurements of stacked soliton pulses and pulses from a dissipative-soliton laser.

  19. Three-dimensional display techniques: description and critique of methods

    International Nuclear Information System (INIS)

    Budinger, T.F.

    1982-01-01

    The recent advances in non invasive medical imaging of 3 dimensional spatial distribution of radionuclides, X-ray attenuation coefficients, and nuclear magnetic resonance parameters necessitate development of a general method for displaying these data. The objective of this paper is to give a systematic description and comparison of known methods for displaying three dimensional data. The discussion of display methods is divided into two major categories: 1) computer-graphics methods which use a two dimensional display screen; and 2) optical methods (such as holography, stereopsis and vari-focal systems)

  20. Three-dimensional spatial imaging in multiphoton ionization rate measurements

    International Nuclear Information System (INIS)

    Bredy, Richard; Camp, Howard A.; Nguyen, Hai; Awata, Takaaki; Shan Bing; Chang Zhenghu; DePaola, B.D.

    2004-01-01

    An experiment is described in which an apparatus is used to demonstrate the feasibility of measuring multiphoton photoionization rates in the interaction of short pulsed lasers with atoms or molecules. With this methodology, the ionization rate is measured as a function of the spatial position in the beam-waist region of the laser through the direct three-dimensional spatial imaging of the ionization events. Thus, if the spatial dependence of the laser beam intensity were known, a series of experiments could yield the intensity dependence of multiphoton ionization without the assumptions or errors that are generally inherent in the integration over one or more dimensions in the laser focal volume

  1. Three-dimensional cranio-facial computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Pozzi Muccelli, R; Stagul, F; Pozzi Muccelli, F; Zuiani, C; Smathers, R

    1986-01-01

    Computed tomography allows today to reconstruct three-dimensional (eD) images fram axial scans. The authors report their experience in cranio-facial pathology achived in two Departments of Radiology (University of Trieste, Italy and University of Standford, California). 3D images have been realized using two different softwares, one of which allows to reconstruct both soft tissue and bone structures. The application in maxillo-facial traumas, cranio-facial malformations and head tumours are disscussed. 3D images turned out to be very useful for the optimal visualization and for the spatial demostration of the lesion and have potential applications in cranio-facial surgery and radiotherapy.

  2. Three-dimensional multifunctional optical coherence tomography for skin imaging

    Science.gov (United States)

    Li, En; Makita, Shuichi; Hong, Young-Joo; Kasaragod, Deepa; Sasaoka, Tomoko; Yamanari, Masahiro; Sugiyama, Satoshi; Yasuno, Yoshiaki

    2016-02-01

    Optical coherence tomography (OCT) visualizes cross-sectional microstructures of biological tissues. Recent developments of multifunctional OCT (MF-OCT) provides multiple optical contrasts which can reveal currently unknown tissue properties. In this contribution we demonstrate multifunctional OCT specially designed for dermatological investigation. And by utilizing it to measure four different body parts of in vivo human skin, three-dimensional scattering OCT, OCT angiography, polarization uniformity tomography, and local birefringence tomography images were obtained by a single scan. They respectively contrast the structure and morphology, vasculature, melanin content and collagen traits of the tissue.

  3. Three-dimensional graphene networks: synthesis,properties and applications

    Institute of Scientific and Technical Information of China (English)

    Yanfeng Ma; Yongsheng Chen

    2015-01-01

    Recently, three-dimensional graphene/graphene oxide(GO) networks(3DGNs) in the form of foams,sponges and aerogels have atracted much atention. 3D structures provide graphene materials with high speciic surface areas, large pore volumes, strong mechanical strengths and fast mass and electron transport,owing to the combination of the 3D porous structures and the excellent intrinsic properties of graphene.his review focuses on the latest advances in the preparation, properties and potential applications of 3D micro-/nano-architectures made of graphene/GO-based networks, with emphasis on graphene foams and sponges.

  4. Kaon-nucleon scattering in three-dimensional technique

    Energy Technology Data Exchange (ETDEWEB)

    Salam, Agus, E-mail: agus.salam@sci.ui.ac.id; Fachruddin, Imam [Departemen Fisika, FMIPA, Universitas Indonesia, Depok 16424 (Indonesia)

    2016-03-11

    Kaon-nucleon (KN) scattering is formulated in the three-dimensional (3D) momentum space, in which the basis state is not expanded into partial waves. Based on this basis the Lippmann-Schwinger equation for the T-matrix is evaluated. We obtain as final equation for the T-matrix elements a set of two coupled integral equations in two variables, which are the momentum’s magnitude and the scattering angle. Calculations for the differential cross section and some spin observables are shown, for which we employ a hadrons exchange model with the second order contributions only.

  5. Three-dimensional image reconstruction. I. Determination of pattern orientation

    International Nuclear Information System (INIS)

    Blankenbecler, Richard

    2004-01-01

    The problem of determining the Euler angles of a randomly oriented three-dimensional (3D) object from its 2D Fraunhofer diffraction patterns is discussed. This problem arises in the reconstruction of a positive semidefinite 3D object using oversampling techniques. In such a problem, the data consist of a measured set of magnitudes from 2D tomographic images of the object at several unknown orientations. After the orientation angles are determined, the object itself can then be reconstructed by a variety of methods using oversampling, the magnitude data from the 2D images, physical constraints on the image, and then iteration to determine the phases

  6. Three-dimensional assessment of facial asymmetry: A systematic review.

    Science.gov (United States)

    Akhil, Gopi; Senthil Kumar, Kullampalayam Palanisamy; Raja, Subramani; Janardhanan, Kumaresan

    2015-08-01

    For patients with facial asymmetry, complete and precise diagnosis, and surgical treatments to correct the underlying cause of the asymmetry are significant. Conventional diagnostic radiographs (submento-vertex projections, posteroanterior radiography) have limitations in asymmetry diagnosis due to two-dimensional assessments of three-dimensional (3D) images. The advent of 3D images has greatly reduced the magnification and projection errors that are common in conventional radiographs making it as a precise diagnostic aid for assessment of facial asymmetry. Thus, this article attempts to review the newly introduced 3D tools in the diagnosis of more complex facial asymmetries.

  7. Tag gas burnup based on three-dimensional FTR analysis

    International Nuclear Information System (INIS)

    Kidman, R.B.

    1976-01-01

    Flux spectra from a three-dimensional diffusion theory analysis of the Fast Test Reactor (FTR) are used to predict gas tag ratio changes, as a function of exposure, for each FTR fuel and absorber subassembly plenum. These flux spectra are also used to predict Xe-125 equilibrium activities in absorber plena in order to assess the feasibility of using Xe-125 gamma rays to detect and distinguish control rod failures from fuel rod failures. Worst case tag burnup changes are used in conjunction with burnup and mass spectrometer uncertainties to establish the minimum spacing of tags which allows the tags to be unambiguously identified

  8. Observation of three dimensional optical rogue waves through obstacles

    International Nuclear Information System (INIS)

    Leonetti, Marco; Conti, Claudio

    2015-01-01

    We observe three-dimensional rogue waves in the speckle distribution of a spatially modulated optical beam. Light is transmitted beyond a partially reflecting obstacle generating optical rogue waves at a controlled position in the shadow of the barrier. When the barrier transmits only 0.07% of the input laser power, we observe the mostly localized event. These results demonstrate that an optimum amount of spatial non-homogeneity maximizes the probability of a gigantic event while the technique we exploit enables to control light behind a fully reflective wall

  9. Three-dimensional phase-field simulations of directional solidification

    Science.gov (United States)

    Plapp, Mathis

    2007-05-01

    The phase-field method has become the method of choice for simulating microstructural pattern formation during solidification. One of its main advantages is that time-dependent three-dimensional simulations become feasible, which makes it possible to address long-standing questions of pattern stability and pattern selection. Here, a brief introduction to the phase-field model and its implementation is given, and its capabilities are illustrated by examples taken from the directional solidification of binary alloys. In particular, the morphological stability of hexagonal cellular arrays and of eutectic lamellar patterns is investigated.

  10. Problems of high temperature superconductivity in three-dimensional systems

    Energy Technology Data Exchange (ETDEWEB)

    Geilikman, B T

    1973-01-01

    A review is given of more recent papers on this subject. These papers have dealt mainly with two-dimensional systems. The present paper extends the treatment to three-dimensional systems, under the following headings: systems with collective electrons of one group and localized electrons of another group (compounds of metals with non-metals-dielectrics, organic substances, undoped semiconductors, molecular crystals); experimental investigations of superconducting compounds of metals with organic compounds, dielectrics, semiconductors, and semi-metals; and systems with two or more groups of collective electrons. Mechanics are considered and models are derived. 86 references.

  11. Three-dimensional characterization of stress corrosion cracks

    DEFF Research Database (Denmark)

    Lozano-Perez, S.; Rodrigo, P.; Gontard, Lionel Cervera

    2011-01-01

    the best spatial resolution. To illustrate the power of these techniques, different parts of dominant stress corrosion cracks in Ni-alloys and stainless steels have been reconstructed in 3D. All relevant microstructural features can now be studied in detail and its relative orientation respect......Understanding crack propagation and initiation is fundamental if stress corrosion cracking (SCC) mechanisms are to be understood. However, cracking is a three-dimensional (3D) phenomenon and most characterization techniques are restricted to two-dimensional (2D) observations. In order to overcome...

  12. Three-dimensional dilatonic gravity's rainbow: Exact solutions

    International Nuclear Information System (INIS)

    Hossein Hendi, Seyed; Eslam Panah, Behzad; Panahiyan, Shahram

    2016-01-01

    Deep relations of dark energy scenario and string theory results into dilaton gravity, on the one hand, and the connection between quantum gravity and gravity's rainbow, on the other hand, motivate us to consider three-dimensional dilatonic black hole solutions in gravity's rainbow. We obtain two classes of the solutions, which are polynomial and logarithmic forms. We also calculate conserved and thermodynamic quantities, and examine the first law of thermodynamics for both classes. In addition, we study thermal stability and show that one of the classes is thermally stable while the other one is unstable.

  13. The three-dimensional crystal structure of cholera toxin

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Rong-Guang; Westbrook, M.L.; Nance, S.; Spangler, B.D. [Argonne National Lab., IL (United States); Scott, D.L. [Yale Univ., New Haven, CT (United States). Dept. of Molecular Biophysics and Biochemistry; Westbrook, E.M. [Northwestern Univ., Evanston, IL (United States)

    1996-02-01

    The clinical manifestations of cholera are largely attributable to the actions of a secreted hexameric AB{sub 5} enterotoxin (choleragen). We have solved the three-dimensional structure of choleragen at 2.5 {Angstrom} resolution and compared the refined coordinates with those of choleragenoid (isolated B pentamer) and the heat-labile enterotoxin from Escherichia coli (LT). The crystalline coordinates provide a detailed view of the stereochemistry implicated in binding to GM1 gangliosides and in carrying out ADP-ribosylation. The A2 chain of choleragen, in contrast to that of LT, is a nearly continuous {alpha}-helix with an interpretable carboxyl tail.

  14. Three-dimensional triaxial testing of marine sediments

    International Nuclear Information System (INIS)

    Nelson, J.D.; Thompson, E.G.

    1981-01-01

    The purpose of this investigation has been to develop testing methods and upgrade equipment for the determination of shear strength of and constitutive relationships for ocean bottom sediments under true three dimensional triaxial states of stress. The research to date has utilized existing 3-D triaxial equipment capable of controlling the three principal stresses independently of each other. Experiments are currently concerned with up-grading the equipment for use with ocean bottom cohesive soils. In addition, stage triaxial tests using conventional laboratory test equipment are being performed

  15. Three-dimensional micro electromechanical system piezoelectric ultrasound transducer

    Science.gov (United States)

    Hajati, Arman; Latev, Dimitre; Gardner, Deane; Hajati, Azadeh; Imai, Darren; Torrey, Marc; Schoeppler, Martin

    2012-12-01

    Here we present the design and experimental acoustic test data for an ultrasound transducer technology based on a combination of micromachined dome-shaped piezoelectric resonators arranged in a flexible architecture. Our high performance niobium-doped lead zirconate titanate film is implemented in three-dimensional dome-shaped structures, which form the basic resonating cells. Adjustable frequency response is realized by mixing these basic cells and modifying their dimensions by lithography. Improved characteristics such as high sensitivity, adjustable wide-bandwidth frequency response, low transmit voltage compatible with ordinary integrated circuitry, low electrical impedance well matched to coaxial cabling, and intrinsic acoustic impedance match to water are demonstrated.

  16. Three-dimensional integrated CAE system applying computer graphic technique

    International Nuclear Information System (INIS)

    Kato, Toshisada; Tanaka, Kazuo; Akitomo, Norio; Obata, Tokayasu.

    1991-01-01

    A three-dimensional CAE system for nuclear power plant design is presented. This system utilizes high-speed computer graphic techniques for the plant design review, and an integrated engineering database for handling the large amount of nuclear power plant engineering data in a unified data format. Applying this system makes it possible to construct a nuclear power plant using only computer data from the basic design phase to the manufacturing phase, and it increases the productivity and reliability of the nuclear power plants. (author)

  17. A simple three dimensional wide-angle beam propagation method

    Science.gov (United States)

    Ma, Changbao; van Keuren, Edward

    2006-05-01

    The development of three dimensional (3-D) waveguide structures for chip scale planar lightwave circuits (PLCs) is hampered by the lack of effective 3-D wide-angle (WA) beam propagation methods (BPMs). We present a simple 3-D wide-angle beam propagation method (WA-BPM) using Hoekstra’s scheme along with a new 3-D wave equation splitting method. The applicability, accuracy and effectiveness of our method are demonstrated by applying it to simulations of wide-angle beam propagation and comparing them with analytical solutions.

  18. Three-Dimensional Magnetic Resonance Imaging of Velopharyngeal Structures

    Science.gov (United States)

    Bae, Youkyung; Kuehn, David P.; Sutton, Bradley P.; Conway, Charles A.; Perry, Jamie L.

    2011-01-01

    Purpose: To report the feasibility of using a 3-dimensional (3D) magnetic resonance imaging (MRI) protocol for examining velopharyngeal structures. Using collected 3D MRI data, the authors investigated the effect of sex on the midsagittal velopharyngeal structures and the levator veli palatini (levator) muscle configurations. Method: Ten Caucasian…

  19. The effect of base image window level selection on the dimensional measurement accuracy of resultant three-dimensional image displays

    International Nuclear Information System (INIS)

    Kurmis, A.P.; Hearn, T.C.; Reynolds, K.J.

    2003-01-01

    Purpose: The aim of this study was to determine the effect of base image window level selection on direct linear measurement of knee structures displayed using new magnetic resonance (MR)-based three-dimensional reconstructed computer imaging techniques. Methods: A prospective comparative study was performed using a series of three-dimensional knee images, generated from conventional MR imaging (MRI) sections. Thirty distinct anatomical structural features were identified within the image series of which repeated measurements were compared at 10 different window grey scale levels. Results: Statistical analysis demonstrated an excellent raw correlation between measurements and suggested no significant difference between measurements made at each of the 10 window level settings (P>0.05). Conclusions: The findings of this study suggest that unlike conventional MR or CT applications, grey scale window level selection at the time of imaging does not significantly affect the visual quality of resultant three-dimensional reconstructed images and hence the accuracy of subsequent direct linear measurement. The diagnostic potential of clinical progression from routine two-dimensional to advanced three-dimensional reconstructed imaging techniques may therefore be less likely to be degraded by inappropriate MR technician image windowing during the capturing of image series

  20. Torso geometry reconstruction and body surface electrode localization using three-dimensional photography.

    Science.gov (United States)

    Perez-Alday, Erick A; Thomas, Jason A; Kabir, Muammar; Sedaghat, Golriz; Rogovoy, Nichole; van Dam, Eelco; van Dam, Peter; Woodward, William; Fuss, Cristina; Ferencik, Maros; Tereshchenko, Larisa G

    We conducted a prospective clinical study (n=14; 29% female) to assess the accuracy of a three-dimensional (3D) photography-based method of torso geometry reconstruction and body surface electrodes localization. The position of 74 body surface electrocardiographic (ECG) electrodes (diameter 5mm) was defined by two methods: 3D photography, and CT (marker diameter 2mm) or MRI (marker size 10×20mm) imaging. Bland-Altman analysis showed good agreement in X (bias -2.5 [95% limits of agreement (LoA) -19.5 to 14.3] mm), Y (bias -0.1 [95% LoA -14.1 to 13.9] mm), and Z coordinates (bias -0.8 [95% LoA -15.6 to 14.2] mm), as defined by the CT/MRI imaging, and 3D photography. The average Hausdorff distance between the two torso geometry reconstructions was 11.17±3.05mm. Thus, accurate torso geometry reconstruction using 3D photography is feasible. Body surface ECG electrodes coordinates as defined by the CT/MRI imaging, and 3D photography, are in good agreement. Copyright © 2017 Elsevier Inc. All rights reserved.