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Value of real time three-dimensional echocardiography in patients with hypertrophic cardiomyopathy: Comparison with two-dimensional echocardiography and magnetic resonance imaging

BICUDO, Leticia S.; TSUTSUI, Jeane M.; SHIOZAKI, Afonso; ROCHITTE, Carlos E.; ARTEAGA, Edmundo; MADY, Charles; RAMIRES, Jose A. F.; MATHIAS JR., Wilson
Fonte: BLACKWELL PUBLISHING Publicador: BLACKWELL PUBLISHING
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
65.84%
Real time three-dimensional echocardiography (RT3DE) has been demonstrated to be an accurate technique to quantify left ventricular (LV) volumes and function in different patient populations. We sought to determine the value of RT3DE for evaluating patients with hypertrophic cardiomyopathy (HCM), in comparison with cardiac magnetic resonance imaging (MRI). Methods: We studied 20 consecutive patients with HCM who underwent two-dimensional echocardiography (2DE), RT3DE, and MRI. Parameters analyzed by echocardiography and MRI included: wall thickness, LV volumes, ejection fraction (LVEF), mass, geometric index, and dyssynchrony index. Statistical analysis was performed by Lin agreement coefficient, Pearson linear correlation and Bland-Altman model. Results: There was excellent agreement between 2DE and RT3DE (Rc = 0.92), 2DE and MRI (Rc = 0.85), and RT3DE and MRI (Rc = 0.90) for linear measurements. Agreement indexes for LV end-diastolic and end-systolic volumes were Rc = 0.91 and Rc = 0.91 between 2DE and RT3DE, Rc = 0.94 and Rc = 0.95 between RT3DE and MRI, and Rc = 0.89 and Rc = 0.88 between 2DE and MRI, respectively. Satisfactory agreement was observed between 2DE and RT3DE (Rc = 0.75), RT3DE and MRI (Rc = 0.83), and 2DE and MRI (Rc = 0.73) for determining LVEF...

Valor da ecocardiografia tridimensional em tempo real em portadores de cardiomiopatia hipertrófica. Comparação com a ecocardiografia bidimensional e a ressonância magnética cardiovascular; Value of real-time three-dimensional echocardiography in patients with hypertrophic cardiomyopathy. Comparison with twodimensional echocardiography and magnetic resonance imaging

Bicudo, Leticia Santos
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 30/11/2007 PT
Relevância na Pesquisa
65.85%
INTRODUÇÃO: A ecocardiografia tridimensional em tempo real (E3DTR) vem provando sua acurácia para quantificar os volumes do ventrículo esquerdo (VE), fração de ejeção (FEVE) e massa em pacientes com cardiomiopatia. Na cardiomiopatia hipertrófica (CMH), onde a morfologia ventricular pode estar muito alterada, a análise das estruturas cardíacas é fundamental para indicação da terapêutica ideal. A ressonância magnética cardiovascular (RMC) é um método superior na análise segmentar do VE em comparação a ecocardiografia bidimensional (E2D), mas com alta complexidade e existente em poucos centros diagnósticos, com contraindicações e limitações para a sua realização. MÉTODOS: Estudo transversal, comparativo, duplo cego, em 20 portadores de CMH, com E2D, E3DTR e RMC realizados com intervalo máximo de 06 meses e armazenados em formato digital. A espessura das paredes, volumes, função sistólica e massa ventricular esquerda foram analisados pelos métodos ecocardiográficos e pela RMC, assim como o movimento anterior sistólico da valva mitral, o índice geométrico do VE e o índice sistólico de dissincronia do VE. ANÁLISE ESTATÍSTICA: Análise estatística pelo coeficiente de concordância de Lin, correlação linear de Pearson e modelo de Bland-Altman. RESULTADOS: Foi obtida exeqüibilidade elevada acima de 94%...

Three-dimensional visualization of human hemoglobin phenotypes with HPLC

Storti-Melo, L. M.; Mangonaro, P. H.; Valencio, C. R.; Traina Junior, C.; Domingos, C. R B
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 354-363
ENG
Relevância na Pesquisa
75.8%
Hemoglobinopathies were included in the Brazilian Neonatal Screening Program on June 6, 2001. Automated high-performance liquid chromatography (HPLC) was indicated as one of the diagnostic methods. The amount of information generated by these systems is immense, and the behavior of groups cannot always be observed in individual analyses. Three-dimensional (3-D) visualization techniques can be applied to extract this information, for extracting patterns, trends or relations from the results stored in databases. We applied the 3-D visualization tool to analyze patterns in the results of hemoglobinopathy based on neonatal diagnosis by HPLC. The laboratory results of 2520 newborn analyses carried out in 2001 and 2002 were used. The Fast, F1, F and A peaks, which were detected by the analytical system, were chosen as attributes for mapping. To establish a behavior pattern, the results were classified into groups according to hemoglobin phenotype: normal (N = 2169), variant (N = 73) and thalassemia (N = 279). 3-D visualization was made with the FastMap DB tool; there were two distribution patterns in the normal group, due to variation in the amplitude of the values obtained by HPLC for the F1 window. It allowed separation of the samples with normal Hb from those with alpha thalassemia...

Airway space changes after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts® total joint prostheses: Three-dimensional assessment

Gonçalves, J. R.; Gomes, L. C R; Vianna, A. P.; Rodrigues, D. B.; Gonçalves, D. A G; Wolford, L. M.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Artigo de Revista Científica Formato: 1014-1022
ENG
Relevância na Pesquisa
75.8%
This study focused on three-dimensional (3D) airway space changes and stability following simultaneous maxillomandibular counterclockwise rotation, mandibular advancement, and temporomandibular joint (TMJ) reconstruction with custom-made total joint prostheses (TMJ Concepts®). Cone beam computed tomography (CBCT) scans of 30 consecutive female patients with irreversibly compromised TMJs were obtained at the following intervals: T1, presurgery; T2, immediately after surgery; and T3, at least 6 months after surgery. The CBCT volumetric datasets were analysed with Dolphin Imaging ® software to evaluate surgical and postsurgical changes to oropharyngeal airway parameters. The average changes in airway surface area (SA), volume (VOL), and minimum axial area (MAA) were, 179.50 mm2, 6302.60 mm3, and 92.23 mm2, respectively, at the longest follow-up (T3 - T1) (P ≤ 0.001). Significant correlations between the amount of mandibular advancement and counterclockwise rotation of the occlusal plane and 3D airway changes were also found (P ≤ 0.01). The results of this investigation showed a significant immediate 3D airway space increase after maxillomandibular counterclockwise rotation and mandibular advancement with TMJ Concepts total joint prostheses...

Reliability and reproducibility of three-dimensional cephalometric landmarks using CBCT: a systematic review

LISBOA,Cinthia de Oliveira; MASTERSON,Daniele; MOTTA,Andréa Fonseca Jardim; MOTTA,Alexandre Trindade
Fonte: Faculdade De Odontologia De Bauru - USP Publicador: Faculdade De Odontologia De Bauru - USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2015 EN
Relevância na Pesquisa
75.69%
Objective : The aim of this study was to review the reliability and reproducibility of 3D-CBCT (cone beam computed tomography) cephalometric landmark identification. Methods : Electronic databases (Pubmed, Scopus, Web of Science) were searched for papers published from 1998 to October 2014. Specific strategies were developed for each database, with the guidance of a librarian. Two reviewers independently analyzed the titles and abstracts for inclusion. The articles that met the inclusion and exclusion criteria were selected for full-text reading, and the selected articles went through methodological quality evaluation. After the exclusion of repeated articles, the titles of the remaining ones were read and 1,328 of them were excluded. The abstracts of 173 articles were read, of which 43 were selected, read in full and submitted to the inclusion and exclusion criteria. Fourteen articles or studies with reliable methodology and reproducibility remained. The data were collected, organized into figures and analyzed for determination of the reliability and reproducibility of the three-dimensional cephalometric landmarks. Results : Overall, the landmarks on the median sagittal line and dental landmarks had the highest reliability, while the landmarks on the condyle...

Three-dimensional scanning with dual-source computed tomography in patients with acute skeletal trauma

Yildirim,Duzgun; Tamam,Cuneyt; Gumus,Terman
Fonte: Faculdade de Medicina / USP Publicador: Faculdade de Medicina / USP
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2010 EN
Relevância na Pesquisa
75.76%
OBJECTIVE: The aim of this study was to compare the efficiency of multiplanar reformatted images and threedimensional images created after multidetector computed tomography examination in detecting acute posttraumatic osseous pathology of the skeletal system. METHOD: Between October 2006 and December 2008, 105 patients with a history of acute trauma were referred to our service. Patients were evaluated with multidetector computed tomography using multiplanary reconstructed images initially (R-I), and six months after this initial evaluation, three-dimensional images were assessed of each patient (R-II). Axial images were used for guiding as a reference Data obtained was recorded and graded according to importance levels of the pathologies. RESULTS: The R-II score was higher in the non-articular and highest in periartricular fractures of the extremities, and thoracic and pelvic cage injuries. For the spinal column, while R-I data was more significant In patients referred with polytrauma, R-II data, was more statistically significant, for short processing and adaptation time to acquiring immediate critical information. For all cases it was seen that three dimensional scans were more efficient in providing the orientation, within a short time. CONCLUSION: By dual source multidedector tomography systems trauma patients may be evaluated by multiplanary and three dimensionally reconstructed images. When used correctly...

The use of three-dimensional cephalometric references in dentoskeletal symmetry diagnosis

Porto,Olavo Cesar Lyra; Freitas,Jairo Curado de; Alencar,Ana Helena Gonçalves de; Estrela,Carlos
Fonte: Dental Press International Publicador: Dental Press International
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2014 EN
Relevância na Pesquisa
75.69%
OBJECTIVE: The aim of this study is to assess dentoskeletal symmetry in cone-beam computed tomography (CBCT) scans of Brazilian individuals with Angle Class I malocclusion. MATERIAL: A total of 47 patients (22 females and 25 males) aged between 11 and 16 years old (14 years) seen in a private radiology service (CIRO, Goiânia, GO, Brazil) were assessed. All CBCT scans were obtained from January, 2009 to December, 2010. Cephalometric measurements were taken by multiplanar reconstruction (axial, coronal and sagittal) using Vista Dent3DPro 2.0 (Dentsply GAC, New York, USA). Minimum, maximum, mean and standard deviation values were arranged in tables, and Student t-test was used to determine statistical significance (P < 0.05). RESULTS: Data were homogeneous, and differences between the right and left sides were not significant. CONCLUSIONS: Cephalometric measurements of Brazilian individuals with Angle Class I malocclusion can be used to establish facial symmetry and three-dimensional standard references which might be useful for orthodontic and surgical planning.

Three-dimensional imaging of the lower esophageal sphincter in gastroesophageal reflux disease.

Stein, H J; DeMeester, T R; Naspetti, R; Jamieson, J; Perry, R E
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /10/1991 EN
Relevância na Pesquisa
65.89%
The resistance of the lower esophageal sphincter to reflux of gastric juice is determined by the integrated effects of radial pressures exerted over the entire length of the sphincter. This can be quantitated by three-dimensional computerized imaging of sphincter pressures obtained by a pullback of radially oriented pressure transducers and by calculating the volume of this image, in other words, the sphincter pressure vector volume. Validation studies showed that sphincter imaging based on a stepwise pullback of a catheter with four or eight radial side holes is superior to a rapid motorized pullback. Compared with 50 healthy volunteers, the total and abdominal sphincter pressure vector volume was lower in 150 patients with increased esophageal acid exposure (p less than 0.001) and decreased with increasing esophageal mucosal damage (p less than 0.01). Calculation of the sphincter pressure vector volume was superior to standard techniques in identifying a mechanically defective sphincter as the cause of increased esophageal acid exposure, particularly in patients without mucosal damage. The Nissen and Belsey fundoplication increased the total and intra-abdominal sphincter pressure vector volume (p less than 0.001) and normalized the three-dimensional sphincter image. Failure to do so was associated with recurrent or persistent reflux. These data indicate that three-dimensional imaging of the lower esophageal sphincter improves the identification of patients who would benefit from an antireflux procedure. Analysis of the three-dimensional sphincter pressure profile should become the standard for evaluation of the lower esophageal sphincter.

Craniofacial growth changes in Malaysian Malay children and young adults: a cross-sectional 3-dimensional CT study.

Yusof, Asilah
Fonte: Universidade de Adelaide Publicador: Universidade de Adelaide
Tipo: Tese de Doutorado Formato: 179837 bytes; 1392121 bytes; 4049479 bytes; 2647287 bytes; 2135271 bytes; 1485266 bytes; 5906657 bytes; 3429546 bytes; 729987 bytes; 172459 bytes; application/pdf; application/pdf; application/pdf; application/pdf; application/pdf; application/pdf; applic
Publicado em //2007 EN
Relevância na Pesquisa
65.9%
This thesis presents a three-dimensional computed tomography (3D-CT) analysis of craniofacial morphology and growth changes in Malaysian Malay subjects. A large number of CT scans (n=205) from birth to adulthood were gathered for this purpose. CT scans were obtained using a GE Lightspeed Plus Scanner. Craniofacial morphology has been analysed based on cephalometric landmarks located in three-dimensions, using specially-designed computer software. The main aims were to produce new 3D normative reference data for selected craniofacial variables in Malaysian Malays and to study growth changes in different craniofacial regions. The specific areas of investigation included: 1. Construction of craniofacial growth references (in tabular and graphical formats) for Malaysian Malays; 2. Quantitative analysis of growth changes in the craniofacial complex using linear and angular measurements derived from landmark data; 3. Comparison of craniofacial measurements between males and females to determine the extent of sexual dimorphism; 4. Quantitative analysis of the nature and extent of directional asymmetry of selected craniofacial regions; 5. Comparisons of selected variables with published data from other ethnic groups. Craniofacial morphology and growth changes were analysed using 3D osseous landmarks. A computer program...

A three-dimensional computed tomography analysis of craniofacial asymmetry in Malaysian infants with cleft lip and palate

Tziavaras, N.; Mihailidis, S.; Rajion, Z.; Yusof, A.; Anderson, P.; Townsend, G.
Fonte: Universiti Sains Malaysia Publicador: Universiti Sains Malaysia
Tipo: Artigo de Revista Científica
Publicado em //2010 EN
Relevância na Pesquisa
75.69%
Background: The application of three-dimensional computed tomography (3D CT) to analyse craniofacial morphology in individuals with cleft lip and palate (CLP) enables detailed assessments to be made of asymmetry in the region of the cleft and in regions distant from the cleft. The aim of this study was to compare craniofacial morphology in a sample of Malaysian infants with unoperated CLP with a control sample of unaffected Malaysian infants. Methods: The study sample comprised 29 individuals: 10 with unilateral CLP (UCLP), 5 with bilateral CLP (BCLP), 7 with cleft lip and primary palate (CLPP), and 7 with isolated cleft palate (ICP). The control sample consisted of 12 non-cleft (NC) infants. All subjects were between 0.4 and 12.2 months of age. Nine mid-facial and 4 nasal bone landmarks were located on 3D CT scans and compared to a midline reference plane, which was created using the landmarks basion, sella, and nasion. Unpaired t tests and F tests were used to compare means and variances between sample groups, whereas paired t tests were used for comparisons within the UCLP and NC groups. Results: Differences in variances of some mid-facial breadths and nasal bone dimensions were found in both male and female cleft groups when compared to the NC sample. In the UCLP group...

Impact of three-dimensional imaging in acquisition of laparoscopic skills in novice operators

Nolan, G.J.; Howell, S.; Hewett, P.
Fonte: Mary Ann Liebert Publicador: Mary Ann Liebert
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
75.83%
BACKGROUND: Three-dimensional (3D) laparoscopes have been developed to maintain the perception of depth in the operating field. Two-dimensional (2D) imaging relies on tactile feedback, visual cues, and previous experience. The aim of this study was to test if 3D laparoscopic vision is superior to 2D laparoscopic vision in training novice operators in completing set laparoscopic tasks. MATERIALS AND METHODS: The study population consisted of 20 interns and medical students. The participants were randomized to completing tasks using a 2D or 3D system. These included pegboard transfer (PT), continuous suturing (CS), and intracorporeal knot-tying (IK). The time to complete the task and number of errors made were recorded. RESULTS: Following adjustment for potential confounders, time to complete CS and IK was significantly longer among participants who used the 2D laparoscope compared with those who used the 3D laparoscope (CS, P<.0001; IK, P<.0001). This same effect was not demonstrated in time to perform PT (PT, P=.04). The 2D laparoscope was associated with a significant increase in the number of errors on the IK task (P<.0001) but not on the PT or CS tasks (PT, P=.35; CS, P=.26). CONCLUSIONS: The 3D system assists novice operators perform more complex laparoscopic tasks in a decreased amount of time and with fewer errors.; Gregory J. Nolan...

Algorithmic approaches to finding cover in three-dimensional, virtual environments

Morgan, David J.
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xvi, 94 p. : ill. (some col.) ;
Relevância na Pesquisa
75.73%
Approved for public release; distribution in unlimited.; In order for an agent to be credible in simulating a human opponent in a first-person combat simulation, it must be able to find and use cover from direct fire weapons. The ability to find cover is fairly intuitive for humans, but current attempts at replicating this ability in computer simulations and video games have been either simplistic or totally missing. This thesis explores a range of algorithms which computer agents can use for finding cover from direct-fire weapons in high-detail, dynamic, three-dimensional environments. The first method treats the enemy as a point light source and uses binary space partition trees to create shadow volumes to find areas of cover. The second method uses a depth-mapping technique to find potential areas where the agent could get behind cover. The third method uses a sensor grid centered on the agent that allows it to check the area around it for cover locations. We implemented the sensor grid technique inside of the first-person shooter computer game America's Army: Operations as a proof of concept.; Major, United States Army

Development of a three dimensional terrain display for a light infantry platoon combat model

Dodd, Thomas G.
Fonte: Monterey, California: Naval Postgraduate School Publicador: Monterey, California: Naval Postgraduate School
Tipo: Tese de Doutorado Formato: vi, 137 p. ill.
EN_US
Relevância na Pesquisa
75.74%
Approved for public release; distribution is unlimited.; As an augmentation to field training, the author identifies a need for an easily available light infantry platoon combat model that presents a realistic view of the battlefield environment. To meet this need, the author examines the feasibility of developing a realistic three dimensional display of a terrain representation on a personal computer. The target computer provides only limited graphics support with an Enhanced Graphics Adapter and all graphics routines are implemented in software. Three methods of terrain representation are examined, and the Dynamic Tactical Simulation (DYNTACS) terrain model is chosen for implementation. The DYNTACS representation uses a specialized triangle drawing procedure written in assembly language, the painter's algorithm for hidden surface removal, and Defense Mapping Agency Digital Terrain Elevation Data. The implementation obtains a display rate between 1.2 and 1.5 seconds on a 80386 based 25 MHz computer. The author concludes that with the addition of enhancements that provide the capability to display cultural features, and model the target acquisition process, the program could be developed into a light infantry platoon combat model or a research tool for examining effects of human factors effects on tactical decision making.; Captain...

3D visualization of an invariant display strategy for hyperspecteral imagery; Three-dimensional visualization of an invariant display strategy for hyperspecteral imagery

Kim, Kang Suk
Fonte: Monterey, California. Naval Postgraduate School Publicador: Monterey, California. Naval Postgraduate School
Tipo: Tese de Doutorado Formato: xvi, 88 p. : ill. (some col.)
Relevância na Pesquisa
75.82%
Approved for public release, distribution is unlimited; Spectral Imagery provides multi-dimensional data, which are difficult to display in standard three-color image formats. Tyo, et al. (2001) propose an invariant display strategy to address this problem. This approach is to mimic the dynamics of human perception. The dimensionality of the data are reduced by using a Principal Component (PC) transformation, and then displayed by making used of a Hue, Saturation, and Value (HSV) display transform. This study addresses the PC transformation strategy , looks for a global eigenvector via 3D visualization of HSV color space information, and examines the suggested algorithm to provide the most intuitive display. The user interface created in this thesis is capable of computing the necessary implementation of the proposed strategy, viewing selected Region of Interest (ROI) in HSV color space model in 3D, and viewing the 2D resultant image. A demonstration application uses Java language including Java2D, Xj3D Player, Document Object Model (DOM) Application Program Interfaces (API), and Extensible 3D Language (X3D). The Java2D API enables the user to load imagery, process data, and render results in a two-dimensional (2D) view. Xj3D and DOM APIs are introduced to visualize Tyo's invariant display strategy in three-dimensional (3D) views and then to save results as X3D scenes. These techniques appear to be inherently valuable and can serve as the basis for further research. Through this thesis...

Crossed-Array Transducer for Real-Time Three-Dimensional Ultrasound Imaging

Joyce, Andrew Waters
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
65.93%
Volumetric ultrasound imaging can present numerous advantages to medical diagnostics, such as increased spatial context, better long-term patient tracking, and reduced imaging times. Creating three-dimensional ultrasound systems is complicated by the attendant increase in system complexity that is required to capture the additional data, and by pulse discrimination imposing repetition frequency limits from the fixed speed of sound in tissue. If the same principles utilized in two-dimensional cross-sectional imaging are applied directly to capture a volumetric data set, the electrical interface, system complexity, and acquisition times grow exponentially. An alternative volumetric imaging method that enables real-time three-dimensional ultrasound imaging using a crossed-array structure is presented in this thesis. The crossed-array transducer developed in this thesis makes use of careful material design and optimization to increase sensitivity and eliminate artifacts. A fine-pitch 1-3 piezocomposite has been optimized for performance in this application. This is combined with a novel method for creating intrinsic apodization within the piezoceramic material. Direct manipulation of the material sensitivity was found to be necessary to eliminate an artifact unique to the large defocused aperture being used: range secondary lobes. An acoustic stack has been designed for the transducer that optimizes sensitivity and reduces manufacturing complexity. Traces on a flexible circuit are used to define the array elements and the polyimide substrate is acoustically integrated as a matching layer. A defocusing rubber lens is used to keep the unfocused axis from experiencing near-field effects. Custom electronics are developed that incorporate a pulser and transmit beamforming system. The pulser uses a new circuit topology to create Ohmic grounding of the array elements when inactive. This is necessary in order to use the same substrate for both send and receive. A transmit beamformer and an advanced control interface have been developed that permit flexible testing using computer control...

Atomic-scale and three-dimensional transmission electron microscopy of nanoparticle morphology

Leary, Rowan Kendall
Fonte: University of Cambridge; Department of Materials Science and Metallurgy Publicador: University of Cambridge; Department of Materials Science and Metallurgy
Tipo: Thesis; doctoral; PhD
EN
Relevância na Pesquisa
75.89%
The burgeoning field of nanotechnology motivates comprehensive elucidation of nanoscale materials. This thesis addresses transmission electron microscope characterisation of nanoparticle morphology, concerning specifically the crystal- lographic status of novel intermetallic GaPd2 nanocatalysts and advancement of electron tomographic methods for high-fidelity three-dimensional analysis. Going beyond preceding analyses, high-resolution annular dark-field imaging is used to verify successful nano-sizing of the intermetallic compound GaPd2. It also reveals catalytically significant and crystallographically intriguing deviations from the bulk crystal structure. So-called ?non-crystallographic? five-fold twinned nanoparticles are observed, adding a new perspective in the long standing debate over how such morphologies may be achieved. The morphological complexity of the GaPd2 nanocatalysts, and many cognate nanoparticle systems, demands fully three-dimensional analysis. It is illustrated how image processing techniques applied to electron tomography reconstructions can facilitate more facile and objective quantitative analysis (?nano-metrology?). However, the fidelity of the analysis is limited ultimately by artefacts in the tomographic reconstruction. Compressed sensing...

Three-dimensional scanning with dual-source computed tomography in patients with acute skeletal trauma

Yildirim, Duzgun; Tamam, Cuneyt; Gumus, Terman
Fonte: Universidade de São Paulo. Faculdade de Medicina Publicador: Universidade de São Paulo. Faculdade de Medicina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; ; ; ; Formato: application/pdf
Publicado em 01/01/2010 ENG
Relevância na Pesquisa
75.76%
OBJECTIVE: The aim of this study was to compare the efficiency of multiplanar reformatted images and threedimensional images created after multidetector computed tomography examination in detecting acute posttraumatic osseous pathology of the skeletal system. METHOD: Between October 2006 and December 2008, 105 patients with a history of acute trauma were referred to our service. Patients were evaluated with multidetector computed tomography using multiplanary reconstructed images initially (R-I), and six months after this initial evaluation, three-dimensional images were assessed of each patient (R-II). Axial images were used for guiding as a reference Data obtained was recorded and graded according to importance levels of the pathologies. RESULTS: The R-II score was higher in the non-articular and highest in periartricular fractures of the extremities, and thoracic and pelvic cage injuries. For the spinal column, while R-I data was more significant In patients referred with polytrauma, R-II data, was more statistically significant, for short processing and adaptation time to acquiring immediate critical information. For all cases it was seen that three dimensional scans were more efficient in providing the orientation, within a short time. CONCLUSION: By dual source multidedector tomography systems trauma patients may be evaluated by multiplanary and three dimensionally reconstructed images. When used correctly...

Improved delineation of short cortical association fibers and gray/white matter boundary using whole-brain three-dimensional diffusion tensor imaging at submillimeter spatial resolution.

Song, AW; Chang, HC; Petty, C; Guidon, A; Chen, NK
Fonte: Universidade Duke Publicador: Universidade Duke
Tipo: Artigo de Revista Científica Formato: 636 - 640
Publicado em /11/2014 ENG
Relevância na Pesquisa
65.88%
Recent emergence of human connectome imaging has led to a high demand on angular and spatial resolutions for diffusion magnetic resonance imaging (MRI). While there have been significant growths in high angular resolution diffusion imaging, the improvement in spatial resolution is still limited due to a number of technical challenges, such as the low signal-to-noise ratio and high motion artifacts. As a result, the benefit of a high spatial resolution in the whole-brain connectome imaging has not been fully evaluated in vivo. In this brief report, the impact of spatial resolution was assessed in a newly acquired whole-brain three-dimensional diffusion tensor imaging data set with an isotropic spatial resolution of 0.85 mm. It was found that the delineation of short cortical association fibers is drastically improved as well as the definition of fiber pathway endings into the gray/white matter boundary-both of which will help construct a more accurate structural map of the human brain connectome.

Enhancements of a three dimensional target model for deep ground penetrating radar systems

Parker, Lonnie
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado Formato: 3454244 bytes; application/pdf
EN_US
Relevância na Pesquisa
75.73%
Both commercial and military industries incorporate the use of Ground Penetrating Radar (GPR). In the case of the military, a stationary object, such as a bunker or tunnel, can be detected. Even high-resolution, three-dimensional (3D) and twodimensional (2D) imagery of energy reflected by the target and its surrounding environment can be produced. This is accomplished using multiple scene perspectives inherent in advanced Synthetic Aperture Radar (SAR) techniques. Although underground target detection can be successful, the return data, usually suffers a significant degree of signal degradation due to the ground medium and target composition. A valid theoretical target model must account for adverse affects such as specular and diffuse reflections, dispersion and attenuation in order to provide an accurate representation of the simulated GPR scenario. It is the aim of this thesis to demonstrate the benefits of a high fidelity GPR target model. Demonstrated in the model is the ability to record estimative return power as a function of multiple variables including frequency, target depth, target composition, ground medium, complex antenna patterns, and transmitted power. Using ray-tracing, a bidirectional reflectance distribution function (BRDF)...

Three-dimensional acquisition and display system for ultrasonic imaging

Raman, Rajeev
Fonte: Rochester Instituto de Tecnologia Publicador: Rochester Instituto de Tecnologia
Tipo: Tese de Doutorado
EN_US
Relevância na Pesquisa
85.97%
Three Dimensional biomedical ultrasonic imaging is relatively in its infancy and many areas for application like tumor detection and identification, virtual surgery planning, among others are being explored. These techniques are expected to provide the medical community with improved diagnostic and analysis capabilities. In order to better understand the image capture and processing issues in these environments, it is necessary to design and implement a reference three dimensional image capture and processing system. In a research environment, the most optimal approach to designing such systems is to leverage existing two dimensional capture technologies and enhance their capabilities for three dimensional imaging. This thesis formulates and implements one approach to developing a three dimensional data acquisition and display system for ultrasonic imaging.