scholarly journals Line-Source Based X-Ray Tomography

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Deepak Bharkhada ◽  
Hengyong Yu ◽  
Hong Liu ◽  
Robert Plemmons ◽  
Ge Wang
Keyword(s):  
Image Reconstruction ◽  
Line Source ◽  
Spot Size ◽  
Projection Data ◽  
Reconstruction Technique ◽  
Focal Spot Size ◽  
X Ray ◽  
Ct Scanners ◽  
Size Limits ◽  
Simultaneous Algebraic Reconstruction Technique

Current computed tomography (CT) scanners, including micro-CT scanners, utilize a point x-ray source. As we target higher and higher spatial resolutions, the reduced x-ray focal spot size limits the temporal and contrast resolutions achievable. To overcome this limitation, in this paper we propose to use a line-shaped x-ray source so that many more photons can be generated, given a data acquisition interval. In reference to the simultaneous algebraic reconstruction technique (SART) algorithm for image reconstruction from projection data generated by an x-ray point source, here we develop a generalized SART algorithm for image reconstruction from projection data generated by an x-ray line source. Our numerical simulation results demonstrate the feasibility of our novel line-source based x-ray CT approach and the proposed generalized SART algorithm.

scholarly journals SART-Type Image Reconstruction from Overlapped Projections

2011 ◽  
Vol 2011 ◽  
pp. 1-7
Author(s):  
Hengyong Yu ◽  
Changguo Ji ◽  
Ge Wang
Keyword(s):  
Image Reconstruction ◽  
Reconstruction Algorithm ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
Multiple Sources ◽  
X Ray ◽  
Type Reconstruction ◽  
Soft Threshold ◽  
Simultaneous Algebraic Reconstruction Technique ◽  
Data Acquisition Process

To maximize the time-integrated X-ray flux from multiple X-ray sources and shorten the data acquisition process, a promising way is to allow overlapped projections from multiple sources being simultaneously on without involving the source multiplexing technology. The most challenging task in this configuration is to perform image reconstruction effectively and efficiently from overlapped projections. Inspired by the single-source simultaneous algebraic reconstruction technique (SART), we hereby develop a multisource SART-type reconstruction algorithm regularized by a sparsity-oriented constraint in the soft-threshold filtering framework to reconstruct images from overlapped projections. Our numerical simulation results verify the correctness of the proposed algorithm and demonstrate the advantage of image reconstruction from overlapped projections.

DEVELOPMENT OF AN IMAGE RECONSTRUCTION METHOD FOR MICRON-CT USING PIXE

2005 ◽  
Vol 15 (03n04) ◽  
pp. 195-202 ◽  
Author(s):  
T. YAMAGUCHI ◽  
K. ISHII ◽  
H. YAMAZAKI ◽  
S. MATSUYAMA ◽  
Y. WATANABE ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Em Algorithm ◽  
Computation Time ◽  
Spot Size ◽  
Biological Research ◽  
Projection Data ◽  
Reconstruction Method ◽  
Ct Image ◽  
X Ray ◽  
Image Reconstruction Method

A prototype of micron-CT for biological research is being developed at Tohoku University. This micron-CT uses a point X-ray source with a spot size of 1μm and an X-ray CCD with 1000×1000 pixels of 8μm×8μm, achieving a spatial resolutions of the order of micro-meter. The event data obtained by the X-ray CCD is statistically poor and the 3 dimensional filtered back projection (3D FBP) algorithm, generally used in image reconstruction of X-ray CT, is not suitable because it is highly sensitive to statistical noise. Hence, we applied the expectation maximization (EM) algorithm for image reconstruction and developed an image reconstruction method using 3D EM algorithm. To confirm the validity of the reconstruction method, we irradiated two hairs inside a micro tube and reconstructed the CT image applying both EM and FBP algorithm on projection data. With 200×200×200 voxels of 4μm×4μm×4μm in the field of view, the computation time was less than 2 mins per iteration on a DELL Precision 650 Workstation 3.2GHz. The resulting EM image showed a better contrast than FBP image, and in the EM reconstructed CT image, we were able to reconstruct the micro tube of 270μm diameter and 45μm wall thickness and to visualize the two hairs inside.

The determination of the focal spot size of an X-ray tube from the radiation beam profile

2015 ◽  
Vol 82 ◽  
pp. 138-145 ◽  
Author(s):  
A.D. Oliveira ◽  
M.J. Fartaria ◽  
J. Cardoso ◽  
L.M. Santos ◽  
C. Oliveira ◽  
...  
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Beam Profile ◽  
Focal Spot Size ◽  
Radiation Beam ◽  
X Ray

X-ray topo-tomography studies of linear dislocations in silicon single crystals

2018 ◽  
Vol 51 (6) ◽  
pp. 1616-1622 ◽  
Author(s):  
Victor Asadchikov ◽  
Alexey Buzmakov ◽  
Felix Chukhovskii ◽  
Irina Dyachkova ◽  
Denis Zolotov ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
High Resolution ◽  
Single Crystals ◽  
Complete Characterization ◽  
Reconstruction Technique ◽  
Algebraic Reconstruction Technique ◽  
X Ray ◽  
Laboratory Setup ◽  
Simultaneous Algebraic Reconstruction Technique

This article describes complete characterization of the polygonal dislocation half-loops (PDHLs) introduced by scratching and subsequent bending of an Si(111) crystal. The study is based on the X-ray topo-tomography technique using both a conventional laboratory setup and the high-resolution X-ray image-detecting systems at the synchrotron facilities at KIT (Germany) and ESRF (France). Numerical analysis of PDHL images is performed using the Takagi–Taupin equations and the simultaneous algebraic reconstruction technique (SART) tomographic algorithm.

scholarly journals Improve X-ray images using quality assurance tests

2021 ◽  
Vol 2114 (1) ◽  
pp. 012034
Author(s):  
M. W. Alhamd ◽  
Aqeel Maryoosh Jary ◽  
Sadeq Naeem Atiyah ◽  
Nazar Ali Abbood
Keyword(s):  
Quality Assurance ◽  
Light Field ◽  
Vertical Axis ◽  
Spot Size ◽  
International Standards ◽  
Focal Spot Size ◽  
X Ray ◽  
Medical Tests ◽  
Reference Doses ◽  
Congruence Test

Abstract In this research, entrance surface doses of patients which are resulted from a classical radiograph in most widespread tests (Chest, skull, abdomen, limbs, …) have been measured with selected instruments in (Specialized surgeries hospital) and one of the private clinic in Baghdad, the instruments are of various origins and different make date. A group of patients (10 patients) for each test and according the average of the resulted doses. Comparison of the patient’s doses, in this research, has been close with the reliable International standards and it has been found that radiological doses are bigger than reference doses ranging (132–1.79) in most of the appliance and the range doses to one whenever the instrument is new and the radiographer has good experience, this increase relates to several functions discussed in the research in detail For the importance of the quality assurance of x-ray instruments, three tests have been performed by three of the instruments only, and these tests are : Beam Alignment test : The Beam Alignment was measured and the x-ray radiograph was found symmetrical round the two axes of the instruments (A, B) but it is about 3 ° away from the vertical axis of the instrument (C). Optical and Radiation Field Congruence Test: The light field coincides with the radiative field in a and b and their mismatch in c. Focal Spot Size Test: The radiation focus area was measured by the star tool and what appeared is that the focus of the x-ray instrument (C) is smaller than the international standards on the contrary of the focus area of the x-ray instrument (E) which is identical with the international standards. From these results reached is that the instruments (A, B) have passed quality assurance tests and they are suitable for work in the present, but the instrument (C) has not passed most of the quality assurance tests, so this instrument should not be used for medical tests This in research is considered the first one for these instruments to evaluate their doses or measure a quality assurance.

scholarly journals 221. Effect of grid bias voltage on the focal spot size of microfocus X-ray tube

1993 ◽  
Vol 49 (8) ◽  
pp. 1246
Author(s):  
Seiichi Mimura ◽  
Noriaki Akagi ◽  
Fumie Kimura ◽  
Shigefumi Kadohisa ◽  
Yasutaka Mikami ◽  
...  
Keyword(s):  
Bias Voltage ◽  
Focal Spot ◽  
Spot Size ◽  
Focal Spot Size ◽  
X Ray

Measurement of the effective focal spot size of an x-ray computer tomograph

1991 ◽  
Vol 25 (6) ◽  
pp. 286-288
Author(s):  
É. I. Rader ◽  
B. S. Reznikov ◽  
A. E. Maslov
Keyword(s):  
Focal Spot ◽  
Spot Size ◽  
Focal Spot Size ◽  
Computer Tomograph ◽  
X Ray
Sign in / Sign up

Export Citation Format

Share Document