Reconstruction of three Dimensional images From Electron Micrographs

1970 ◽  
Vol 28 ◽  
pp. 246-247
Author(s):  
D.J. DeRosier
Keyword(s):  
Heavy Metal ◽  
Image Reconstruction ◽  
Optical Density ◽  
Electron Micrographs ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Dimensional Electron ◽  
Density Measurements ◽  
Dimensional Image

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.

Criteria and Methods for Reliable Three-Dimensional Image Reconstruction

1974 ◽  
Vol 32 ◽  
pp. 330-331
Author(s):  
R. A. Crowther
Keyword(s):  
Image Reconstruction ◽  
Finite Number ◽  
Density Distribution ◽  
Electron Micrographs ◽  
Mathematical Problem ◽  
Three Dimensional ◽  
Ideal Case ◽  
Dimensional Image ◽  
General Object ◽  
The Ideal

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.

OVERLAPPING FORE AND OSEM FOR 3D PET IMAGE RECONSTRUCTION

2004 ◽  
Vol 16 (05) ◽  
pp. 238-243
Author(s):  
WEI-MIN JENG ◽  
MING-CHUNG CHIANG
Keyword(s):  
Image Reconstruction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Dimensional Image ◽  
Two Dimensional Image ◽  
Positron Emission ◽  
Dimensional Reconstruction ◽  
Abnormal Metabolism ◽  
Pet Image Reconstruction ◽  
Pet Scanners

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.

Influence of Electron Noise on Three-dimensional Image Reconstruction

1976 ◽  
Vol 31 (12) ◽  
pp. 1717-1721 ◽  
Author(s):  
R. Hegerl ◽  
W. Hoppe
Keyword(s):  
Image Reconstruction ◽  
Three Dimensional ◽  
Two Dimensional ◽  
Three Dimensional Reconstruction ◽  
Dimensional Image ◽  
Integral Dose ◽  
Dimensional Reconstruction ◽  
Level Of Significance

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.

AN IMPROVED 3DRP PET IMAGE RECONSTRUCTION METHOD WITH REBINNED DIRECT IMAGE ESTIMATE

2006 ◽  
Vol 18 (05) ◽  
pp. 237-245
Author(s):  
WEI-MIN JENG ◽  
HSUAN-HUI WANG
Keyword(s):  
Image Reconstruction ◽  
Image Quality ◽  
Three Dimensional ◽  
Simulation Software ◽  
Direct Image ◽  
Projection Data ◽  
Reconstruction Method ◽  
Two Dimensional ◽  
Dimensional Image

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.

Three-Dimensional Structure of Cloned T3 Connector Protein at 1.6nm Resolution

1990 ◽  
Vol 48 (1) ◽  
pp. 282-283
Author(s):  
José L. Carrascosa ◽  
José M. Valpuesta ◽  
Hisao Fujisawa
Keyword(s):  
Dna Sequences ◽  
Expression Vector ◽  
Three Dimensional ◽  
Deae Cellulose ◽  
Dna Packaging ◽  
Dimensional Structure ◽  
Two Dimensional ◽  
Freezing And Thawing ◽  
Three Dimensional Structure ◽  
Dimensional Reconstruction

The head to tail connector of bacteriophages plays a fundamental role in the assembly of viral heads and DNA packaging. In spite of the absence of sequence homology, the structure of connectors from different viruses (T4, Ø29, T3, P22, etc) share common morphological features, that are most clearly revealed in their three-dimensional structure. We have studied the three-dimensional reconstruction of the connector protein from phage T3 (gp 8) from tilted view of two dimensional crystals obtained from this protein after cloning and purification.DNA sequences including gene 8 from phage T3 were cloned, into Bam Hl-Eco Rl sites down stream of lambda promotor PL, in the expression vector pNT45 under the control of cI857. E R204 (pNT89) cells were incubated at 42°C for 2h, harvested and resuspended in 20 mM Tris HC1 (pH 7.4), 7mM 2 mercaptoethanol, ImM EDTA. The cells were lysed by freezing and thawing in the presence of lysozyme (lmg/ml) and ligthly sonicated. The low speed supernatant was precipitated by ammonium sulfate (60% saturated) and dissolved in the original buffer to be subjected to gel nitration through Sepharose 6B, followed by phosphocellulose colum (Pll) and DEAE cellulose colum (DE52). Purified gp8 appeared at 0.3M NaCl and formed crystals when its concentration increased above 1.5 mg/ml.

scholarly journals A Self-Established “Machining-Measurement-Evaluation” Integrated Platform for Taper Cutting Experiments and Applications

Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 929
Author(s):  
Xudong Yang ◽  
Zexiao Li ◽  
Linlin Zhu ◽  
Yuchu Dong ◽  
Lei Liu ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Precision Machining ◽  
Two Dimensional ◽  
Dimensional Image ◽  
Two Dimensional Image ◽  
Integrated Platform ◽  
Hard And Brittle Materials ◽  
Ultra Precision ◽  
Cutting Experiments

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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