3-D spatial resolution of 350 μm pitch pixelated CdZnTe detectors for imaging applications

Yongzhi Yin, Ximeng Chen, Heyu Wu, Sergey Komarov, Alfred Garson, Qiang Li, Qingzhen Guo, Henric Krawczynski, Ling Jian Meng, Yuan Chuan Tai

Research output: Contribution to journalArticle

Abstract

We are currently investigating the feasibility of using highly pixelated Cadmium Zinc Telluride (CdZnTe) detectors for sub-500 μm resolution PET imaging applications. A 20 mm× 20 mm× 5 mm CdZnTe substrate was fabricated with 350 μm pitch pixels (250 μm anode pixels with 100 μm gap) and coplanar cathode. Charge sharing among the pixels of a 350 μm pitch detector was studied using collimated 122 keV and 511 keV gamma ray sources. For a 350 μm pitch CdZnTe detector, scatter plots of the charge signal of two neighboring pixels clearly show more charge sharing when the collimated beam hits the gap between adjacent pixels. Using collimated Co-57 and Ge-68 sources, we measured the count profiles and estimated the intrinsic spatial resolution of 350 μm pitch detector biased at-1000 V. Depth of interaction was analyzed based on two methods, i.e., cathode/anode ratio and electron drift time, in both 122 keV and 511 keV measurements. For single-pixel photopeak events, a linear correlation between cathode/anode ratio and electron drift time was shown, which would be useful for estimating the DOI information and preserving image resolution in CdZnTe PET imaging applications.

Original languageEnglish (US)
Article number6304947
Pages (from-to)9-15
Number of pages7
JournalIEEE Transactions on Nuclear Science
Volume60
Issue number1
DOIs
StatePublished - Jan 1 2013

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Keywords

  • CdZnTe detectors
  • charge sharing
  • imaging applications
  • spatial resolution

ASJC Scopus subject areas

  • Nuclear and High Energy Physics
  • Nuclear Energy and Engineering
  • Electrical and Electronic Engineering

Cite this

Yin, Y., Chen, X., Wu, H., Komarov, S., Garson, A., Li, Q., Guo, Q., Krawczynski, H., Meng, L. J., & Tai, Y. C. (2013). 3-D spatial resolution of 350 μm pitch pixelated CdZnTe detectors for imaging applications. IEEE Transactions on Nuclear Science, 60(1), 9-15. [6304947]. https://doi.org/10.1109/TNS.2012.2213611