title: 3-D Spatial Resolution of 350μm Pitch Pixelated CdZnTe Detectors for Imaging Applications.
abstract: We are currently investigating the feasibility of using highly pixelated Cadmium Zinc Telluride (CdZnTe) detectors for sub-500μm resolution PET imaging applications. A 20 mm × 20 mm × 5 mm CdZnTe substrate was fabricated with 350μm pitch pixels (250μm anode pixels with 100μm gap) and coplanar cathode. Charge sharing among the pixels of a 350μm pitch detector was studied using collimated 122 keV and 511 keV gamma ray sources. For a 350μm 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 350μm 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.
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, Lanzhou 73000, Gansu, China.
authors.forename: Yongzhi
authors.initials: Y
authors.lastname: Yin
authors.affiliation: School of Nuclear Science and Technology, Lanzhou University, Lanzhou 73000, Gansu, China.
authors.forename: Ximeng
authors.initials: X
authors.lastname: Chen
authors.affiliation: Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 USA.
authors.forename: Heyu
authors.initials: H
authors.lastname: Wu
authors.affiliation: Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 USA.
authors.forename: Sergey
authors.initials: S
authors.lastname: Komarov
authors.affiliation: Department of Physics, Washington University in St. Louis, St. Louis, MO 63110 USA.
authors.forename: Alfred
authors.initials: A
authors.lastname: Garson
authors.affiliation: Department of Physics, Washington University in St. Louis, St. Louis, MO 63110 USA, and also with the State Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi'an 710072, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Li
authors.affiliation: Department of Physics, Washington University in St. Louis, St. Louis, MO 63110 USA.
authors.forename: Qingzhen
authors.initials: Q
authors.lastname: Guo
authors.affiliation: Department of Physics, Washington University in St. Louis, St. Louis, MO 63110 USA.
authors.forename: Henric
authors.initials: H
authors.lastname: Krawczynski
authors.affiliation: Department of Nuclear, Plasma and Radiological Engineering, University of Illinois at Urbana-Champaign, Urbana, IL 61822 USA.
authors.forename: Ling-Jian
authors.initials: LJ
authors.lastname: Meng
authors.affiliation: Department of Radiology, Washington University School of Medicine, St. Louis, MO 63110 USA.
authors.forename: Yuan-Chuan
authors.initials: YC
authors.lastname: Tai
keywords: CdZnTe detectors; charge sharing; imaging applications; spatial resolution