Optimization of the grid frequencies and angles in digital radiography imaging

Dong Sik Kim; Sanggyun Lee

doi:10.1117/12.877930

15 March 2011 Optimization of the grid frequencies and angles in digital radiography imaging

Dong Sik Kim, Sanggyun Lee

Proceedings Volume 7961, Medical Imaging 2011: Physics of Medical Imaging; 79610B (2011) https://doi.org/10.1117/12.877930
Event: SPIE Medical Imaging, 2011, Lake Buena Vista (Orlando), Florida, United States

Abstract

In order to reduce the grid artifacts, which are caused by using the antiscatter grid in obtaining x-ray digital images, we analyze the grid artifacts based on the multiplicative image formation model instead of the traditional additive model, and apply filters to suppress the artifact terms. The artifact terms are aliases of the modulated terms from the harmonics of the grid frequency. Hence, several filters are required to efficiently suppress the grid artifacts. However, applying filters also distort the original image that will be recovered. If the distance between the origin and the center frequency of the artifact term is relatively large, then we can suppress the artifact term less distorting the original image. In this paper, by increasing the distances for a given sampling frequency of the image detector, we design antiscatter grids, which are good in terms of efficient grid artifact reduction. In order to design optimal grids, we formulate min-max optimization problems and provide optimal grid frequencies for a fixed grid angle with respect to the sampling direction of the image detector and optimal grid angles for a fixed grid frequency. We then propose using rotated grids with the optimal grid angles in digital radiography imaging. By applying band-rejection filters to the artifact, we can considerably reduce the grid artifacts when comparing to the traditional non-rotated grid case for real x-ray images.

Citation Download Citation

Dong Sik Kim and Sanggyun Lee "Optimization of the grid frequencies and angles in digital radiography imaging", Proc. SPIE 7961, Medical Imaging 2011: Physics of Medical Imaging, 79610B (15 March 2011); https://doi.org/10.1117/12.877930

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