CdZnTe Detectors: What You Need to Know

Objectives CdZnTe (CZT) is a semiconductor detector material that is increasingly being used in nuclear medicine applications. As more medical imaging devices incorporate CZT, it is important to become familiar with its material properties and associated physics, and their effects on image quality. The purpose of this educational exhibit is to present some basics of CZT detectors to nuclear medicine professionals in an approachable manner.

Methods This educational exhibit will include 1) a review of the unique properties of CZT detector materials, 2) a schematic of common geometry and electronic setup 3) a step-by-step description of signal generation starting with photon interaction, electron-cloud formation and transportation, signal readout, and finally image reconstruction, 4) a description of the small-pixel effect and its contribution to improved spatial and energy resolution, and 5) a discussion of the advantages and disadvantages of CZT compared to other materials (e.g. NaI(Tl)) used in nuclear medicine.

Results Diagrams, animations, and analogies will be used to explain complex, yet relevant, physics concepts. Explanations will be based on concepts familiar to nuclear medicine professionals. As an example, Figure 1 describes the configuration of a typical CZT detector geometry. The pixel pitch of the anode determines both the spatial resolution and energy resolution due to the small pixel effect. These parameters, as well as others that affect image quality, will be described through visualizations.

Conclusions After reading this educational exhibit, participants should have a better understanding of the basic physics of CZT detectors, how signals are created and processed into images, how CZT compares to other detector materials, as well as challenges that must be overcome in the future. RESEARCH SUPPORT:

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