Paper
2 March 2006 Comparison measurements of DQE for two flat panel detectors: fluoroscopic detector vs. cone beam CT detector
Author Affiliations +
Abstract
The physical performance of two flat panel detectors (FPD) has been evaluated using a standard x-ray beam quality set by IEC, namely RQA5. The FPDs evaluated in this study are based on an amorphous silicon photodiode array that is coupled to a thallium-doped Cesium Iodide scintillator and to a thin film transistor (TFT) array. One detector is the PaxScan 2520 that is designed for fluoro imaging, and has a small dynamic range and a large image lag. The other detector is the PaxScan 4030CB that is designed for cone beam CT, and has a large dynamic range (>16-bit), a reduced image lag and many imaging modes. Varian Medical Systems manufactured both detectors. The linearity of the FPDs was investigated by using an ionization chamber and aluminum filtration in order to obtain the beam quality. Since the FPDs are used in fluoroscopic mode, image lag of the FPD was measured in order to investigate its effect on this study, especially its effect on DQE. The spatial resolution of the FPDs was determined by obtaining the pre-sampling modulation transfer function for each detector. A sharp edge was used in accordance to IEC 62220-1. Next, the Normalized Noise Power Spectrum (NNPS) was calculated for various exposures levels at RQA5 radiation quality. Finally, the DQE of each FPD was obtained with a modified version of the international standard set by IEC 62220-1. The results show that the physical performance in DQE and MTF of the PaxScan 4030CB is superior to that of PaxScan2520.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ricardo Betancourt Benítez, Ruola Ning, and David Conover "Comparison measurements of DQE for two flat panel detectors: fluoroscopic detector vs. cone beam CT detector", Proc. SPIE 6142, Medical Imaging 2006: Physics of Medical Imaging, 61422K (2 March 2006); https://doi.org/10.1117/12.655584
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Sensors

Modulation transfer functions

X-ray sources

Ionization

Spatial frequencies

X-ray computed tomography

X-rays

Back to Top