scholarly journals Improve spatial resolution by Modeling Finite Focal Spot (MFFS) for industrial CT reconstruction

2014 ◽  
Vol 22 (25) ◽  
pp. 30641 ◽  
Author(s):  
Ming Chang ◽  
Yongshun Xiao ◽  
Zhiqiang Chen
Keyword(s):  
Spatial Resolution ◽  
Focal Spot ◽  
Ct Reconstruction ◽  
Industrial Ct

The influence of focal spot blooming on high-contrast spatial resolution in CT imaging

2015 ◽  
Vol 42 (10) ◽  
pp. 6011-6020 ◽  
Author(s):  
Joshua Grimes ◽  
Xinhui Duan ◽  
Lifeng Yu ◽  
Ahmed F. Halaweish ◽  
Nicole Haag ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Focal Spot ◽  
Ct Imaging ◽  
High Contrast

Image Quality in Mammography with Special Reference to Anti-Scatter Grids and the Magnification Technique

1986 ◽  
Vol 27 (4) ◽  
pp. 467-479 ◽  
Author(s):  
B. Nielsen ◽  
G. Fagerberg
Keyword(s):  
Image Quality ◽  
Spatial Resolution ◽  
Scattered Radiation ◽  
Focal Spot ◽  
Absorbed Dose ◽  
Standard Technique ◽  
Spot Size ◽  
Limiting Factor ◽  
Film System ◽  
Tube Potential

Some of the parameters determining image quality in mammography are analyzed: the effects of primary photon spectra, focal spot size and screen-film systems on spatial resolution are discussed as are scattered radiation, development temperature and absorbed dose. The parameters limiting spatial resolution and contrast are evaluated for the standard and magnification techniques. Methods of reducing scattered radiation to improve contrast are evaluated. Scatter to primary ratios for different scatter reducing methods are compared, using the physical quantity energy imparted. For the standard technique the spatial resolution has been found to be limited by the fluorescent screen. With magnification technique the focal spot is the weakest link for the spatial resolution. The contrast is mainly set by the amount of scatter using the standard technique considering the use of a low tube potential (∼25 kVp). Using the magnification technique the amount of scatter is so small, that the tube potential is the limiting factor. We have found the optimized standard mammographic technique to be achieved under the following conditions: 25 kVp, 0.3 to 0.6 mm focal spot, film-focus distance 500 mm, anti-scatter grid, developing temperature 36 to 38°C and 4 minutes total processing time with the screen-film system we have used. In magnification technique an air gap of at least 20 mm is desired. With an FFD of about 500 mm this will give a magnification ratio of 1.8 to 2.0 and a 0.1 mm × 0.1 mm focus spot is mandatory. With this technique, it is necessary to use a faster screen-film system than that used in standard mammography.

scholarly journals X-ray shadowgraphy applications in ablatively accelerated planar foil studies

1992 ◽  
Vol 10 (4) ◽  
pp. 685-688 ◽  
Author(s):  
V. A. Bolotin ◽  
I. N. Burdonsky ◽  
V. V. Gavrilov ◽  
A. Yu. Gol'tsov ◽  
E. V. Zhuzhukalo ◽  
...  
Keyword(s):  
Laser Pulse ◽  
Spatial Resolution ◽  
Spectral Range ◽  
Focal Spot ◽  
Signal To Noise Ratio ◽  
Signal To Noise ◽  
Plasma Flows ◽  
X Ray ◽  
Noise Ratio ◽  
Drive Laser Pulse

The article reviews experiments on flash X radiography of laser-accelerated foils. The spatial resolution, sensitivity, spectral range, and signal-to-noise ratio of measurements were carefully optimized and characterized. The method was used at the Mishen facility to measure a distribution of mass ablative rate across the focal spot and for observation of the transverse plasma flows during the drive laser pulse.

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