Scattered radiation in flat-detector based cone-beam CT: propagation of signal, contrast, and noise into reconstructed volumes

Jens Wiegert; Steffen Hohmann; Matthias Bertram

doi:10.1117/12.710196

13 March 2007 Scattered radiation in flat-detector based cone-beam CT: propagation of signal, contrast, and noise into reconstructed volumes

Jens Wiegert, Steffen Hohmann, Matthias Bertram

Author Affiliations +

Proceedings Volume 6510, Medical Imaging 2007: Physics of Medical Imaging; 65100X (2007) https://doi.org/10.1117/12.710196
Event: Medical Imaging, 2007, San Diego, CA, United States

Abstract

This paper presents a novel framework for the systematic assessment of the impact of scattered radiation in .at-detector based cone-beam CT. While it is well known that scattered radiation causes three di.erent types of artifacts in reconstructed images (inhomogeneity artifacts such as cupping and streaks, degradation of contrast, and enhancement of noise), investigations in the literature quantify the impact of scatter mostly only in terms of inhomogeneity artifacts, giving little insight, e.g., into the visibility of low contrast lesions. Therefore, for this study a novel framework has been developed that in addition to normal reconstruction of the CT (HU) number allows for reconstruction of voxelized expectation values of three additional important characteristics of image quality: signal degradation, contrast reduction, and noise variances. The new framework has been applied to projection data obtained with voxelized Monte-Carlo simulations of clinical CT data sets of high spatial resolution. Using these data, the impact of scattered radiation was thoroughly studied for realistic and clinically relevant patient geometries of the head, thorax, and pelvis region. By means of spatially resolved reconstructions of contrast and noise propagation, the image quality of a scenario with using standard antiscatter grids could be evaluated with great detail. Results show the spatially resolved contrast degradation and the spatially resolved expected standard deviation of the noise at any position in the reconstructed object. The new framework represents a general tool for analyzing image quality in reconstructed images.

Citation Download Citation

Jens Wiegert, Steffen Hohmann, and Matthias Bertram "Scattered radiation in flat-detector based cone-beam CT: propagation of signal, contrast, and noise into reconstructed volumes", Proc. SPIE 6510, Medical Imaging 2007: Physics of Medical Imaging, 65100X (13 March 2007); https://doi.org/10.1117/12.710196

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available