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1
Tomographic Image Reconstruction Techniques for ...
1988-07-11

... Abstract : Computerized tomography (CT) offers one method for accurately reconstructing the spatial features of a spectroscopic source having ...

DTIC Science & Technology

2
Modeling of polychromatic attenuation using computed tomography reconstructed images
1999-01-01

This paper presents a procedure for estimating an accurate model of the CT imaging process including

NASA Technical Reports Server (NTRS)

3
Restoration and reconstruction from overlapping ... - MODIS Website

Resampling the overlapping swaths to produce a more accurate image on a uniform grid requires restoration and reconstruction, The one-pass restoration and ...

NASA Website

4
Image reconstruction method for a two-layer tissue structure accounts for chest-wall effects in breast imaging
2008-01-01

We develop a new tomographic imaging reconstruction algorithm for a two-layer tissue structure. Simulations and phantom experiments show more accurate reconstruction of target optical properties compared with those results obtained from a semi-infinite tissue model for layered structures. This improvement is mainly ...

PubMed Central

5
Image reconstruction for PET/CT scanners: past achievements and future challenges
2010-10-01

PET is a medical imaging modality with proven clinical value for disease diagnosis and treatment monitoring. The integration of PET and CT on modern scanners provides a synergy of the two imaging modalities. Through different mathematical algorithms, PET data can be reconstructed into the spatial distribution of the injected ...

PubMed Central

6
Accurate Ray Tracing and Least Square Reconstruction Algorithms for Geotomographic Imaging.
1988-01-01

An improvement of the geotomography technique is presented. It includes a data collection model, a ray-tracing algorithm, a least squares reconstruction algorithm, and application of a selective weighting smoothing window.

National Technical Information Service (NTIS)

7
Image reconstruction method for a two-layer tissue structure accounts for chest-wall effects in breast imaging.

We develop a new tomographic imaging reconstruction algorithm for a two-layer tissue structure. Simulations and phantom experiments show more accurate reconstruction of target optical properties compared with those results obtained from a semi-infinite tissue model for layered structures. This improvement is mainly ...

PubMed

8
An FBP image reconstruction algorithm for x-ray differential phase contrast CT.
2008-03-18

Most recently, a novel data acquisition method has been proposed and experimentally implemented for x-ray differential phase contrast computed tomography (DPC-CT), in which a conventional x-ray tube and a Talbot-Lau type interferometer were utilized in data acquisition. The divergent nature of the data acquisition system requires a divergent-beam image ...

PubMed

9
An FBP image reconstruction algorithm for x-ray differential phase contrast CT
2008-03-18

Most recently, a novel data acquisition method has been proposed and experimentally implemented for x-ray differential phase contrast computed tomography (DPC-CT), in which a conventional x-ray tube and a Talbot-Lau type interferometer were utilized in data acquisition. The divergent nature of the data acquisition system requires a divergent-beam image ...

PubMed Central

10
Accurate image reconstruction from few-view and limited-angle data in diffraction tomography
2008-07-01

We present a method for obtaining accurate image reconstruction from highly sparse data in diffraction tomography (DT). A practical need exists for reconstruction from few-view and limited-angle data, as this can greatly reduce required scan times in DT. Our method does this by minimizing the total variation (TV) ...

PubMed Central

11
WKB quasistatic reconstruction of layered biological tissues.
2004-01-01

A novel electrical impedance tomography method is introduced for reconstruction of layered biological tissues. The method utilizes a recently proposed image series expansion scheme in conjunction with the WKB approximation. This results in a locality feature, assigning analytically to each image term a local impedance associated with a ...

PubMed

12
An evaluation of three algorithms for reconstructing images from data with missing projections
1988-02-01

Three iterative reconstruction algorithms for reconstructing images from tomographic data with missing projections are evaluated. One algorithm iteratively minimizes a squared error criterion, the other two, both transform algorithms, estimate the missing projections by placing constraints on the missing data. These algorithms were ...

Energy Citations Database

13
3D reconstruction of industrial sheetmetal parts with hybrid point-line photogrammetry
2003-09-01

A new approach for three-dimensional reconstruction of industrial parts with non-metric image sequences and hybrid point-line photogrammetry is proposed. Non-metric image sequence and CAD-designed data are used as source of information. The strategy of our approach is to reconstruct the parts automatically with ...

NASA Astrophysics Data System (ADS)

14
Tilted plane Feldkamp type reconstruction algorithm for spiral cone beam CT
2005-11-15

An approximate image reconstruction method for spiral cone beam computed tomography (CT), called tilted plane Feldkamp type reconstruction algorithm (TPFR), is presented in this paper, which extends Feldkamp cone beam reconstruction algorithm to deal with its inaccuracy and artifact problems caused by large cone ...

Energy Citations Database

15
SEM (Scanning Electron Microscope) Image Analysis of Grain Growth in Microwave-Annealed Alumina.
1989-01-01

An image analysis technique using a scanning electron microscope has been developed for accurately reconstructing grain boundaries to measure small changes in grain size and shape. The technique measures individual grain perimeters, areas, Feret's diamete...

National Technical Information Service (NTIS)

16
Automatic sound speed selection in photoacoustic image reconstruction using an autofocus approach.
2011-09-01

The reconstruction of images in photoacoustic tomography is reliant on specifying the speed of sound within the propagation medium. However, for in vivo imaging, this value is not normally accurately known. Here, an autofocus approach for automatically selecting the sound speed is proposed. This is based on ...

PubMed

17
Image series expansion for electrical impedance tomography.
2004-09-28

A novel electrical impedance tomography method is introduced for reconstruction of layered biological tissues. The method utilizes a recently proposed image series expansion scheme in conjunction with the WKB approximation. This results in a locality feature, assigning analytically to each image term a local impedance associated with a ...

PubMed

18
EdgeCS: edge guided compressive sensing reconstruction
2010-07-01

Compressive sensing (CS) reconstructs images from a small number of projections. We propose EdgeCS - edge guided CS reconstruction - to recover images of higher qualities from fewer measurements than the current state-of-the-art methods. Accurate edge information can significantly improve ...

NASA Astrophysics Data System (ADS)

19
Transport- and diffusion-based optical tomography in small domains: a comparative study
2007-09-01

We compare reconstructions based on the radiative transport and diffusion equations in optical tomography for media of small sizes. While it is well known that the diffusion approximation is less accurate to describe light propagation in such media, it has not yet been shown how this inaccuracy affects the images obtained with ...

NASA Astrophysics Data System (ADS)

20
Statistical modeling and reconstruction of randoms precorrected PET data.
2006-12-01

Randoms precorrected positron emission tomography (PET) data is formed as the difference of two Poisson random variables. Its exact probability mass function (PMF) is inconvenient for use in likelihood-based iterative image reconstruction as it contains an infinite summation. The shifted Poisson model is a tractable approximation to this PMF but requires ...

PubMed

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21
A residual correction method for high-resolution PET reconstruction with application to on-the-fly Monte Carlo based model of positron range
2010-02-21

Purpose: The quality of tomographic images is directly affected by the system model being used in image reconstruction. An accurate system matrix is desirable for high-resolution image reconstruction, but it often leads to high computation cost. In this work the authors ...

PubMed Central

22
Figures of merit for comparing reconstruction algorithms with a volume-imaging PET scanner.
1994-03-01

For volume-imaging PET scanners, no septa are used to maximize the sensitivity by collecting events oblique to the scanner axis. We answer two questions: (i) how does the performance of an image reconstruction algorithm for a volume-imaging PET scanner depend on its general dimensions? and (ii) at what point is a ...

PubMed

23
On the use of frequency-domain reconstruction algorithms for photoacoustic imaging.
2011-08-01

We investigate the use of a frequency-domain reconstruction algorithm based on the nonuniform fast Fourier transform (NUFFT) for photoacoustic imaging (PAI). Standard algorithms based on the fast Fourier transform (FFT) are computationally efficient, but compromise the image quality by artifacts. In our previous work we have developed ...

PubMed

24
On the use of frequency-domain reconstruction algorithms for photoacoustic imaging
2011-08-01

We investigate the use of a frequency-domain reconstruction algorithm based on the nonuniform fast Fourier transform (NUFFT) for photoacoustic imaging (PAI). Standard algorithms based on the fast Fourier transform (FFT) are computationally efficient, but compromise the image quality by artifacts. In our previous work we have developed ...

NASA Astrophysics Data System (ADS)

25
ECT image reconstruction based on the generalized vector sampled pattern matching method
2010-08-01

Electrical capacitance tomography (ECT) is a new technology for testing parameters of solid-air two-phase flow during the past decades. The key technique of ECT is the fast and accurate image reconstruction. In this paper, the principle and measuring process of ECT were elaborated, the reconstruction algorithm ...

NASA Astrophysics Data System (ADS)

26
Limited data image reconstruction in optoacoustic tomography by constrained total variation minimization
2011-02-01

Optoacoustic Tomography (OAT) is an emerging hybrid imaging technique with great potential for a wide range of biomedical imaging applications. Assuming point-like transducers, analytic algorithms are available for image reconstruction, but they are applicable only when the measured data are densely sampled on an ...

NASA Astrophysics Data System (ADS)

27
Three-dimensional nonlinear image reconstruction for microwave biomedical imaging.
2004-03-01

Active microwave imaging has attracted significant interests in biomedical applications, in particular for breast imaging. However, the high electrical contrasts in breast tissue also increases the difficulty of forming an accurate image because of the increased multiple scattering. To model such strong ...

PubMed

28
SPIRiT: Iterative self-consistent parallel imaging reconstruction from arbitrary k-space.
2010-08-01

A new approach to autocalibrating, coil-by-coil parallel imaging reconstruction, is presented. It is a generalized reconstruction framework based on self-consistency. The reconstruction problem is formulated as an optimization that yields the most consistent solution with the calibration and acquisition data. The ...

PubMed

29
SPIRiT: Iterative Self-consistent Parallel Imaging Reconstruction from Arbitrary k-Space
2010-08-01

A new approach to autocalibrating, coil-by-coil parallel imaging reconstruction is presented. It is a generalized reconstruction framework based on self consistency. The reconstruction problem is formulated as an optimization that yields the most consistent solution with the calibration and acquisition data. The ...

PubMed Central

30
DART: A Practical Reconstruction Algorithm for Discrete Tomography.
2011-03-24

In this paper, we present an iterative reconstruction algorithm for discrete tomography, called discrete algebraic reconstruction technique (DART). DART can be applied if the scanned object is known to consist of only a few different compositions, each corresponding to a constant gray value in the reconstruction. Prior knowledge of the ...

PubMed

31
Electrical CT image reconstruction technique for powder flow in petroleum refinery process
2008-03-01

A new reconstruction method called sampled pattern matching (SPM) was applied to the image reconstruction of an electrical capacitance computed tomography in powder flow in a vertical pipe for petroleum refinery process. This new method is able to achieve stable convergence without the use of an empirical value. Experiments were ...

NASA Astrophysics Data System (ADS)

32
Fluorescence lifetime imaging by using time-gated data acquisition
2007-10-01

The use of the time gating technique for lifetime reconstruction in the Fourier domain is a novel technique. Time gating provides sufficient data points in the time domain for reliable application of the Fourier transform, which is essential for the time deconvolution of the system of the integral equations employed in the reconstruction. The Fourier ...

NASA Astrophysics Data System (ADS)

33
Signal-to-noise ratios for attenuation correction in PET imaging
1994-12-01

Attenuation correction is an important part of accurate image reconstruction in positron tomography. The usual correction method involves direct measurement of attenuation correction factors (ACFs). A reconstruct-reproject method, which has been suggested as providing superior noise properties, is sometimes ...

Energy Citations Database

34
Iterative motion compensated reconstruction for parallel imaging using an orbital navigator.
2011-04-01

A new navigator-guided motion-compensated MR image reconstruction for segmented Cartesian imaging using multiple reception coils is presented. In-plane patient motion, comprising translation and rotation, is quantified for each scan segment by an orbital navigator. A robust and accurate approach to extract the ...

PubMed

35
Targeted-ROI imaging in electron paramagnetic resonance imaging
2007-07-01

Electron paramagnetic resonance imaging (EPRI) is a technique that has been used for in vivo oxygen imaging of small animals. In continuous wave (CW) EPRI, the measurement can be interpreted as a sampled 4D Radon transform of the image function. The conventional filtered-backprojection (FBP) algorithm has been used widely for ...

NASA Astrophysics Data System (ADS)

36
Detection geometry and reconstruction error in magnetic source imaging
1993-11-01

A recently developed reconstruction algorithm for magnetic source imaging exploits prior knowledge about source location, source power density, detector geometry, and detector noise power to obtain an explicit estimate of the reconstruction error. This paper demonstrates the application of the new algorithm to the optimal design of ...

Energy Citations Database

37
Optimization of CT image reconstruction algorithms for the lung tissue research consortium (LTRC)
2006-03-01

To create a repository of clinical data, CT images and tissue samples and to more clearly understand the pathogenetic features of pulmonary fibrosis and emphysema, the National Heart, Lung, and Blood Institute (NHLBI) launched a cooperative effort known as the Lung Tissue Resource Consortium (LTRC). The CT images for the LTRC effort must contain ...

NASA Astrophysics Data System (ADS)

38
Quantitative cardiac SPECT reconstruction with reduced image degradation due to patient anatomy
1994-12-01

Patient anatomy has complicated effects on cardiac SPECT images. The authors investigated reconstruction methods which substantially reduced these effects for improved image quality. A 3D mathematical cardiac-torso (MCAT) phantom which models the anatomical structures in the thorax region were used in the study. The phantom was ...

Energy Citations Database

39
Forensic 3D scene reconstruction
2000-05-01

Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and ...

NASA Astrophysics Data System (ADS)

40
Forensic 3D Scene Reconstruction
1999-10-12

Traditionally law enforcement agencies have relied on basic measurement and imaging tools, such as tape measures and cameras, in recording a crime scene. A disadvantage of these methods is that they are slow and cumbersome. The development of a portable system that can rapidly record a crime scene with current camera imaging, 3D geometric surface maps, and ...

Energy Citations Database

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First Page Previous Page 1 2 3 Next Page Last Page
 
41
Wavelength optimization in spectral near-infrared optical tomography
2009-02-01

Multi-spectral Near Infrared tomographic imaging has the potential to provide information about patho-physiological function of soft tissue. However, the specific choice of wavelengths used is crucial for the accurate separation of such parameters. It will be demonstrated that the conventionally believed choice of large set of wavelengths can be ...

NASA Astrophysics Data System (ADS)

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