Investigation of limited-view image reconstruction in optoacoustic tomography employing a priori structural information

2010 ◽  
Author(s):  
Chao Huang ◽  
Alexander A. Oraevsky ◽  
Mark A. Anastasio
Keyword(s):  
Image Reconstruction ◽  
Structural Information ◽  
A Priori ◽  
Optoacoustic Tomography

The NCEM One-Angstrom Microscope Project Reaches 0.89Å Resolution

2000 ◽  
Vol 6 (S2) ◽  
pp. 1192-1193 ◽  
Author(s):  
Michael A. O'Keefe
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Image Reconstruction ◽  
Structural Information ◽  
Computer Software ◽  
Image Simulation ◽  
Resolution Limit ◽  
Transmission Electron ◽  
Better Than

Transmission electron microscopy to a resolution of 0.89Å has been achieved at the National Center for Electron Microscopy and is available to electron microscopists who have a requirement for this level of resolution. Development of this capability commenced in 1993, when the National Center for Electron Microscopy agreed to fund a proposal for a unique facility, a one- Ångstrom microscope (OÅM).2 The OÅM project provides materials scientists with transmission electron microscopy at a resolution better than one Angstrom by exploiting the significantly higher information limit of a FEG-TEM over its Scherzer resolution limit. To turn the misphased information beyond the Scherzer limit into useful resolution, the OÅM requires extensive image reconstruction. One method chosen was reconstruction from off-axis holograms; another was reconstruction from focal series of underfocused images. The OÅM is then properly a combination of a FEG-TEM (a CM300FEG-UT) together with computer software able to generate sub-Ångstrom images from experimental images obtained on the FEG-TEM.Before the advent of the OÅM, NCEM microscopists relied on image simulation to obtain structural information beyond the TEM resolution limit.

Using Deconvolution to Improve PET Spatial Resolution in OSEM Iterative Reconstruction

2007 ◽  
Vol 46 (02) ◽  
pp. 231-235 ◽  
Author(s):  
I. Castiglioni ◽  
G. Russo ◽  
M. Tana ◽  
F. Dell'Acqua ◽  
M. Gilardi ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Spatial Resolution ◽  
Penalty Function ◽  
Iterative Reconstruction ◽  
A Priori ◽  
Image Deconvolution ◽  
A Priori Information ◽  
Novel Approach ◽  
Priori Information ◽  
Pet Image Reconstruction

Summary Objectives : A novel approach to the PET image reconstruction is presented, based on the inclusion of image deconvolution during conventional OSEM reconstruction. Deconvolution is here used to provide a recovered PET image to be included as “a priori" information to guide OSEM toward an improved solution. Methods : Deconvolution was implemented using the Lucy-Richardson (LR) algorithm: Two different deconvolution schemes were tested, modifying the conventional OSEM iterative formulation: 1) We built a regularizing penalty function on the recovered PET image obtained by deconvolution and included i in the OSEM iteration. 2) After each conventional global OSEM iteration, we deconvolved the resulting PET image and used this “recovered" version as the initialization image for the next OSEM iteration. Tests were performed on both simulated and acquired data. Results : Compared to the conventional OSEM, both these strategies, applied to simulated and acquired data, showed an improvement in image spatial resolution with better behavior in the second case. In this way, small lesions, present on data, could be better discriminated in terms of contrast. Conclusions : Application of this approach to both simulated and acquired data suggests its efficacy in obtaining PET images of enhanced quality.

Image processing and image reconstruction with the use of a-priori information

1990 ◽  
Author(s):  
Chin-Tu Chen ◽  
Valen E. Johnson ◽  
Xiaoping Hu ◽  
Wing H. Wong ◽  
Charles E. Metz
Keyword(s):  
Image Processing ◽  
Image Reconstruction ◽  
A Priori ◽  
A Priori Information ◽  
Priori Information
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