20 April 2005 Scan equalization digital radiography (SEDR): implementation with a flat-panel detector
Author Affiliations +
We are constructing and investigating a Scan Equalization Digital Radiography (SEDR) system using an a-Si:H based flat-panel detector. With this system, slot-scan imaging with regionally adjustable beam width is used to achieve scatter rejection and exposure equalization. As part of the SEDR system, we have developed and implemented an electronic aft-collimation technique, referred to as the Alternate Line Erasure and Readout (ALER), by modifying the electronics of an a-Si:H/a-Se based flat-panel detector to alter the sequence of image readout. Instead of reading the image line by line, the leading edge line of the scanning fan beam is reset to erase the scatter component accumulated prior to the arrival of the fan beam while the trailing edge line is read out to acquire the exposure signals integrated following the exposure of the scanning fan beam. This resetting and readout cycle is repeated and synchronized to the motion of the scanning fan beam. To guide the selection of the slot width in implementing the SEDR system, measurements of the scatter-to-primary ratio (SPR) and relative contrast-to-noise ratio (RCNR) were made and compared for various slot widths. Our preliminary testing has demonstrated that it is feasible to implement an electronic aft-collimation technique to effectively reject scattered radiation without attenuating the primary x-rays and without using a bulky, heavy aft-collimator. The SPR and RCNR measurements indicated that the performance of the slot-scan imaging technique improves with narrower slot width and is generally better than the anti-scatter grid method.
© (2005) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Xinming Liu, Xinming Liu, Chris C. Shaw, Chris C. Shaw, Mustafa C. Altunbas, Mustafa C. Altunbas, Tianpeng Wang, Tianpeng Wang, "Scan equalization digital radiography (SEDR): implementation with a flat-panel detector", Proc. SPIE 5745, Medical Imaging 2005: Physics of Medical Imaging, (20 April 2005); doi: 10.1117/12.597217; https://doi.org/10.1117/12.597217

Back to Top