Paper
18 March 2015 Anti-scatter grid artifact elimination for high resolution x-ray imaging CMOS detectors
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Abstract
Higher resolution in dynamic radiological imaging such as angiography is increasingly being demanded by clinicians; however, when standard anti-scatter grids are used with such new high resolution detectors, grid-line artifacts become more apparent resulting in increased structured noise that may overcome the contrast signal improvement benefits of the scatter-reducing grid. Although grid-lines may in theory be eliminated by dividing the image of a patient taken with the grid by a flat-field image taken with the grid obtained prior to the clinical image, unless the remaining additive scatter contribution is subtracted in real-time from the dynamic clinical image sequence before the division by the reference image, severe grid-line artifacts may remain. To investigate grid-line elimination, a stationary Smit Rӧntgen X-ray grid (line density: 70 lines/cm, grid ratio 13:1) was used with both a 75 micron-pixel CMOS detector and a standard 194 micron-pixel flat panel detector (FPD) to image an artery block insert placed in a modified uniform frontal head phantom for a 20 x 20cm FOV (approximately). Contrast and contrast-to-noise ratio (CNR) were measured with and without scatter subtraction prior to grid-line correction. The fixed pattern noise caused by the grid was substantially higher for the CMOS detector compared to the FPD and caused a severe reduction of CNR. However, when the scatter subtraction corrective method was used, the removal of the fixed pattern noise (grid artifacts) became evident resulting in images with improved CNR.
© (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
R. Rana, V. Singh, A. Jain, D. R. Bednarek, and S. Rudin "Anti-scatter grid artifact elimination for high resolution x-ray imaging CMOS detectors", Proc. SPIE 9412, Medical Imaging 2015: Physics of Medical Imaging, 941243 (18 March 2015); https://doi.org/10.1117/12.2081430
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Cited by 4 scholarly publications and 1 patent.
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KEYWORDS
CMOS sensors

Sensors

Arteries

Image resolution

Head

X-ray imaging

X-rays

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