Program Information
Relative Object Detectability Evaluation of a New High Resolution A-Se Direct Detection System Compared to Indirect Micro-Angiographic Fluoroscopic (MAF) Detectors
M Russ1*, S Setlur Nagesh1 , C Ionita1 , C Scott2 , K Karim2 , D Bednarek1 , S Rudin1 , (1) Toshiba Stroke and Vascular Research Center, University at Buffalo (SUNY), Buffalo, NY, (2) University of Waterloo, Waterloo, ON,
Presentations
WE-G-204-5 (Wednesday, July 15, 2015) 4:30 PM - 6:00 PM Room: 204
Purpose: To evaluate the task specific imaging performance of a new 25μm pixel pitch, 1000μm thick amorphous selenium direct detection system with CMOS readout for typical angiographic exposure parameters using the relative object detectability (ROD) metric.
Methods: The ROD metric uses a simulated object function weighted at each spatial frequency by the detectors’ detective quantum efficiency (DQE), which is an intrinsic performance metric. For this study, the simulated objects were aluminum spheres of varying diameter (0.05-0.6mm). The weighted object function is then integrated over the full range of detectable frequencies inherent to each detector, and a ratio is taken of the resulting value for two detectors. The DQE for the 25μm detector was obtained from a simulation of a proposed a-Se detector using an exposure of 200μR for a 50keV x-ray beam. This a-Se detector was compared to two microangiographic fluoroscope (MAF) detectors [the MAF-CCD with pixel size of 35μm and Nyquist frequency of 14.2 cycles/mm and the MAF-CMOS with pixel size of 75μm and Nyquist frequency of 6.6 cycles/mm] and a standard flat-panel detector (FPD with pixel size of 194μm and Nyquist frequency of 2.5cycles/mm).
Results: ROD calculations indicated vastly superior performance by the a-Se detector in imaging small aluminum spheres. For the 50μm diameter sphere, the ROD values for the a-Se detector compared to the MAF-CCD, the MAF-CMOS, and the FPD were 7.3, 9.3 and 58, respectively. Detector performance in the low frequency regime was dictated by each detector’s DQE(0) value.
Conclusion: The a-Se with CMOS readout is unique and appears to have distinctive advantages of incomparable high resolution, low noise, no readout lag, and expandable design. The a-Se direct detection system will be a powerful imaging tool in angiography, with potential break-through applications in diagnosis and treatment of neuro-vascular disease.
Funding Support, Disclosures, and Conflict of Interest: Supported by NIH Grant: 2R01EB002873 and an equipment grant from Toshiba Medical Systems Corporation
Contact Email: