Solution to the three-dimensional image reconstruction problem from two-dimensional parallel projections

1993 ◽  
Vol 10 (5) ◽  
pp. 869 ◽  
Author(s):  
M. Defrise ◽  
R. Clack ◽  
D. Townsend
2004 ◽  
Vol 16 (05) ◽  
pp. 238-243
Author(s):  
WEI-MIN JENG ◽  
MING-CHUNG CHIANG

Positron emission tomography (PET) images can be used to judge whether or not a person's bodily tissue is showing abnormal metabolism, providing a tool for early diagnosis and treatment of illnesses. Contemporary PET scanners have retracted their septa in order to increase the collected coincidental events. Thus, the protocol either needs to undergo three-dimensional image reconstruction, or use rebinning formulas to perform the less expensive two-dimensional image reconstruction for final images. Reconstruction using the second method saves image reconstruction time. The main goal of the paper is to further improve the performance by overlapping the rebinning and two-dimensional reconstruction operations, so as to early start in reconstruction, and to be able to undergo image reconstruction based on the pipelined direct sinograms. Frequency distance relations are analyzed in detail to generate the Fourier transformed sinograms in order for subsequent pipelined stages of reconstruction. The two-dimensional reconstruction operation does not have to wait until the completion of all sinogram generations, therefore it can hide most of the time spent in rebinning operations. The associated parameters can be pre-calculated indiscriminately beforehand for best performance.


1976 ◽  
Vol 31 (12) ◽  
pp. 1717-1721 ◽  
Author(s):  
R. Hegerl ◽  
W. Hoppe

AbstractA three-dimensional reconstruction requires the same integral dose as a conventional two-dimensional micrograph provided that the level of significance and the resolution are identical. The necessary dose D for one of the K projections in a reconstruction series is, therefore, the integral dose divided by K.


2006 ◽  
Vol 18 (05) ◽  
pp. 237-245
Author(s):  
WEI-MIN JENG ◽  
HSUAN-HUI WANG

The quality of traditional two-dimensional image reconstruction for PET has been efficiently improved by three-dimensional image reconstruction, but the sensitivity of the data and the quality of the image are restricted by the limit of modality physics. In analytical image reconstruction algorithm, 3DRP method compensates the unmeasured events by forward projection based on the initial direct image estimate. However, the original 3DRP method merely depends on the parallel projections without taking into account the oblique projections. In our proposed 3DRP-SSRB method, we improve the first image estimate by incorporating the rebinned oblique data. SSRB method was used to perform the rebinning operation to make uses of the oblique projection data to improve the sensitivity information. And then project the improved image estimate forward and reconstruct the final image. Conflicting parameters of reconstructed image quality of 3DRP are experimented by simulated three-dimensional phantom study with regard to both system sensitivity and image quality factors. PET simulation software package was used to conduct the experiment along with the MATLAB software to evaluate the effectiveness of two-dimensional FBP, 3DRP, and our proposed 3DRP-SSRB methods. The result demonstrated its better image quality by having better mean squared error numbers in most of output image slices.


Author(s):  
D.J. DeRosier

The purpose of image reconstruction is to determine, in an objective way, the three dimensional structure of a particle from a set of two dimensional electron micrographs.1 Data, in the form of optical density measurements, are gathered from the set of micrographs and are used to determine a three dimensional set of densities representing the distribution of matter, or, in most cases, the distribution of the heavy metal stain. This distribution is graphically displayed section by section on transparent sheets which may then be stacked to give the three dimensional image.


Author(s):  
R. A. Crowther

The reconstruction of a three-dimensional image of a specimen from a set of electron micrographs reduces, under certain assumptions about the imaging process in the microscope, to the mathematical problem of reconstructing a density distribution from a set of its plane projections.In the absence of noise we can formulate a purely geometrical criterion, which, for a general object, fixes the resolution attainable from a given finite number of views in terms of the size of the object. For simplicity we take the ideal case of projections collected by a series of m equally spaced tilts about a single axis.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 929
Author(s):  
Xudong Yang ◽  
Zexiao Li ◽  
Linlin Zhu ◽  
Yuchu Dong ◽  
Lei Liu ◽  
...  

Taper-cutting experiments are important means of exploring the nano-cutting mechanisms of hard and brittle materials. Under current cutting conditions, the brittle-ductile transition depth (BDTD) of a material can be obtained through a taper-cutting experiment. However, taper-cutting experiments mostly rely on ultra-precision machining tools, which have a low efficiency and high cost, and it is thus difficult to realize in situ measurements. For taper-cut surfaces, three-dimensional microscopy and two-dimensional image calculation methods are generally used to obtain the BDTDs of materials, which have a great degree of subjectivity, leading to low accuracy. In this paper, an integrated system-processing platform is designed and established in order to realize the processing, measurement, and evaluation of taper-cutting experiments on hard and brittle materials. A spectral confocal sensor is introduced to assist in the assembly and adjustment of the workpiece. This system can directly perform taper-cutting experiments rather than using ultra-precision machining tools, and a small white light interference sensor is integrated for in situ measurement of the three-dimensional topography of the cutting surface. A method for the calculation of BDTD is proposed in order to accurately obtain the BDTDs of materials based on three-dimensional data that are supplemented by two-dimensional images. The results show that the cutting effects of the integrated platform on taper cutting have a strong agreement with the effects of ultra-precision machining tools, thus proving the stability and reliability of the integrated platform. The two-dimensional image measurement results show that the proposed measurement method is accurate and feasible. Finally, microstructure arrays were fabricated on the integrated platform as a typical case of a high-precision application.


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