A New Flat-Panel Digital Mammography Detector with Avalanche Photoconductor and High-Resolution Field Emitter Readout
Abstract
A new concept of flat-panel imager (FPI) with avalanche gain and high resolution (with 50 micron pixel size) is being investigated for improving the imaging performance of digital mammography at low doses and high spatial frequencies, which are critical for the detection of subtle breast abnormalities and the development of digital tomosynthesis. The detector employs an avalanche photoconductor, amorphous selenium (a-Se), called HARP, to detect and amplify the optical signal generated by a structured scintillator, cesium iodide (CsI), and form a charge image that is read out by a high-resolution field emitter array (FEA). The authors call the proposed detector SAPHIRE (Scintillator-Avalanche Photoconductor with High Resolution Emitter Readout). This investigation showed that the avalanche gain of SAPHIRE permits the use of high-resolution (HR) type CsI, which has not been used in existing FPI due to its low light output. HR CsI can provide better imaging performance at high spatial frequencies than existing digital mammography detectors. They also investigated the factors affecting the resolution of the FEA readout method. Their results showed that the dominant source of image blur is the spread of the FEA electron beam. The results of these calculations show that an effective pixel size of 50 microns is feasible.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 2005
- Accession Number
- ADA438154
Entities
People
- Wei Zhao
Organizations
- State University of New York