DocumentCode :
3559361
Title :
Effect of Oblique X-ray Incidence in Flat-Panel Computed Tomography of the Breast
Author :
Badano, Aldo ; Kyprianou, Iacovos S. ; Freed, Melanie ; Jennings, Robert J. ; Sempau, Josep
Author_Institution :
Div. of Imaging & Appl. Math., U.S. Food & Drug Adm., Silver Spring, MD
Volume :
28
Issue :
5
fYear :
2009
fDate :
5/1/2009 12:00:00 AM
Firstpage :
696
Lastpage :
702
Abstract :
We quantify the variation in resolution due to anisotropy caused by oblique X-ray incidence in indirect flat-panel detectors for computed tomography breast imaging systems. We consider a geometry and detector type utilized in breast computed tomography (CT) systems currently being developed. Our methods rely on MANTIS, a combined X-ray, electron, and optical Monte Carlo transport open source code. The physics models are the most accurate available in general-purpose Monte Carlo packages in the diagnostic energy range. We consider maximum-obliquity angles of 10deg and 13deg at the centers of the 30 and 40 cm detector edges, respectively, and 16deg at the corner of the detector. Our results indicate that blur is asymmetric and that the resolution properties vary significantly with the angle (or location) of incidence. Our results suggest that the asymmetry can be as high as a factor of 2.6 between orthogonal directions. Anisotropy maps predicted by MANTIS provide an understanding of the effect that such variations have on the imaging system and allow more accurate modeling and optimization of breast CT systems. These maps of anisotropy across the detector could lead to improved reconstruction and help motivate physics-based strategies for computer detection of breast lesions.
Keywords :
Monte Carlo methods; cancer; computerised tomography; diagnostic radiography; edge detection; image reconstruction; mammography; medical image processing; tumours; MANTIS; anisotropic mapping; breast cancer lesions; breast imaging system; flat-panel computed tomography; oblique X-ray incidence effect; optical Monte Carlo transport open source code; optical imaging simulation; Anisotropic magnetoresistance; Breast; Computed tomography; Detectors; Geometrical optics; Image resolution; Monte Carlo methods; Optical imaging; X-ray detection; X-ray imaging; Breast computed tomography (CT); Cesium Iodide; Monte Carlo simulation; phosphor blur; phosphor screen; Anisotropy; Cesium; Computer Simulation; Female; Humans; Image Interpretation, Computer-Assisted; Imaging, Three-Dimensional; Iodides; Mammography; Monte Carlo Method; Normal Distribution; Tomography, X-Ray Computed;
fLanguage :
English
Journal_Title :
Medical Imaging, IEEE Transactions on
Publisher :
ieee
Conference_Location :
12/9/2008 12:00:00 AM
ISSN :
0278-0062
Type :
jour
DOI :
10.1109/TMI.2008.2010443
Filename :
4703241
Link To Document :
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