Image quality evaluation of direct-conversion digital mammography system with new dual a-Se layer detector

Takao Kuwabara; Nobuyuki Iwasaki; Tomonari Sendai; Ryosuke Furue; Toshitaka Agano

doi:10.1117/12.811469

13 March 2009 Image quality evaluation of direct-conversion digital mammography system with new dual a-Se layer detector

Takao Kuwabara, Nobuyuki Iwasaki, Tomonari Sendai, Ryosuke Furue, Toshitaka Agano

Author Affiliations +

Proceedings Volume 7258, Medical Imaging 2009: Physics of Medical Imaging; 72584P (2009) https://doi.org/10.1117/12.811469
Event: SPIE Medical Imaging, 2009, Lake Buena Vista (Orlando Area), Florida, United States

Abstract

To increase the detection performance of breast cancers in mammograms, we need to improve shape delineation of micro calcifications and tumors. We accomplished this by developing a direct-conversion mammography system with an optical reading method and a new dual a-Se layer detector. The system achieved both small pixel size (50 micrometer) and a high Detective Quantum Efficiency (DQE) realized by 100 % of fill factor and noise reduction. We evaluated image quality performance and determined the best exposure conditions. We measured DQE and Modulation Transfer Function(MTF) according to the IEC62220-1-2. High DQE was maintained at a low radiation dosage, indicating that the optical reading method accompanies low noises. Response of MTF was maintained at up to the Nyquist frequency of 10 cyc/mm, which corresponds to 50 micrometer pixel size. To determine the best exposure conditions, we measured Contrast to Noise Ratio (CNR) and visually evaluated images of a resected breast under conditions of MoMo, MoRh, and WRh. There were occasional disagreements between the exposure conditions for achieving the maximum CNR and those for the best image graded by the visual evaluation. This was probably because CNR measurement does not measure effects of scattered X-ray. The images verified the improvement in detection and delineation performance of micro calcifications and tumors.

Citation Download Citation

Takao Kuwabara, Nobuyuki Iwasaki, Tomonari Sendai, Ryosuke Furue, and Toshitaka Agano "Image quality evaluation of direct-conversion digital mammography system with new dual a-Se layer detector", Proc. SPIE 7258, Medical Imaging 2009: Physics of Medical Imaging, 72584P (13 March 2009); https://doi.org/10.1117/12.811469

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