Image quality of direct conversion detectors for mammography and radiography: a theoretical comparison

James Gordon Mainprize; Martin J. Yaffe

doi:10.1117/12.479999

5 June 2003 Image quality of direct conversion detectors for mammography and radiography: a theoretical comparison

Proceedings Volume 5030, Medical Imaging 2003: Physics of Medical Imaging; (2003) https://doi.org/10.1117/12.479999
Event: Medical Imaging 2003, 2003, San Diego, California, United States

Abstract

Direct conversion detectors have the potential to provide very high resolution and high detective quantum efficiency (DQE). Selection of a material that is appropriate for the task is dictated by the material properties. A linear cascaded systems analysis of DQE is used to predict the performance of several detector materials such as amorphous Se, CdZnTe, and PbI₂. A model is used to predict the spatial frequency-dependent DQE(f) for each material. This model includes: (1) x-ray absorption, (2) K fluorescence, (3) conversion gain, and (4) incomplete charge collection. A depth-dependent approach is used to account for gain variations and charge transport characteristics that change throughout the detector. In the model a parallel cascade, and non-elementary stages are used to model the effect of K-fluorescence reabsorption followed by incomplete charge collection. The DQE(f) is determined across an x-ray energy range of 10 to 100 keV for each material under typical bias conditions ranging from 0.1 V/μm to 10 V/μm. K-fluorescence escape and reabsorption blurring can cause marked reductions in the DQE(f). It is further reduced by incomplete charge collection which can theoretically decrease the DQE(f) by as much as 50% in extreme situations. This model will help determine key factors that will influence material selection for direct conversion x-ray systems.

Citation Download Citation

James Gordon Mainprize and Martin J. Yaffe "Image quality of direct conversion detectors for mammography and radiography: a theoretical comparison", Proc. SPIE 5030, Medical Imaging 2003: Physics of Medical Imaging, (5 June 2003); https://doi.org/10.1117/12.479999

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