Signal and noise characteristics of a CdTe-based photon counting detector: cascaded systems analysis and experimental studies

Xu Ji; Ran Zhang; Yongshuai Ge; Guang-Hong Chen; Ke Li

doi:10.1117/12.2255063

9 March 2017 Signal and noise characteristics of a CdTe-based photon counting detector: cascaded systems analysis and experimental studies

Xu Ji, Ran Zhang, Yongshuai Ge, Guang-Hong Chen, Ke Li

Author Affiliations +

Proceedings Volume 10132, Medical Imaging 2017: Physics of Medical Imaging; 1013207 (2017) https://doi.org/10.1117/12.2255063
Event: SPIE Medical Imaging, 2017, Orlando, Florida, United States

Abstract

Recent advances in single photon counting detectors (PCDs) are opening up new opportunities in medical imaging. However, the performance of PCDs is not flawless. Problems such as charge sharing may deteriorate the performance of PCD. This work studied the dependence of the signal and noise properties of a cadmium telluride (CdTe)-based PCD on the charge sharing effect and the anti-charge sharing (ACS) capability offered by the PCD. Through both serial and parallel cascaded systems analysis, a theoretical model was developed to trace the origin of charge sharing in CdTe-based PCD, which is primarily related to remote k-fluorescence re-absorption and spatial spreading of charge cloud. The ACS process was modeled as a sub-imaging state prior to the energy thresholding stage, and its impact on the noise power spectrum (NPS) of PCD can be qualitatively determined by the theoretical model. To validate the theoretical model, experimental studies with a CdTe-based PCD system (XC-FLITE X1, XCounter AB) was performed. Two x-ray radiation conditions, including an RQA-5 beam and a 40 kVp beam, were used for the NPS measurements. Both theoretical predictions and experimental results showed that ACS makes the NPS of the CdTe-based PCD flatter, which corresponds to reduced noise correlation length. The flatness of the NPS is further boosted by increasing the energy threshold or reducing the x-ray energy, both of which reduce the likelihood of registering multiple counts from the same incidenting x-ray photon.

Conference Presentation

Citation Download Citation

Xu Ji, Ran Zhang, Yongshuai Ge, Guang-Hong Chen, and Ke Li "Signal and noise characteristics of a CdTe-based photon counting detector: cascaded systems analysis and experimental studies", Proc. SPIE 10132, Medical Imaging 2017: Physics of Medical Imaging, 1013207 (9 March 2017); https://doi.org/10.1117/12.2255063

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