Development and Characterization of Modular Readout Design for Two-Panel Head-and-Neck Dedicated PET System Based on CZT Detectors

Cadmium zinc telluride (CZT) detectors are suitable for various applications due to the good energy resolution and the simple pixilation to achieve high spatial resolution. Our group is developing a two-panel head-and-neck dedicated positron emission tomography system based on CZT detectors. Each panel will consist of 150 CZT crystals (4 <tex-math notation="LaTeX">× </tex-math> 4 <tex-math notation="LaTeX">× </tex-math> 0.5 cm 3 ) covering an area of 20 <tex-math notation="LaTeX">× </tex-math> 15 cm 2 in an edge-on configuration to achieve high detector efficiency at 511 keV. In this work, we present the design and development of a full data acquisition (DAQ) chain that enables a low noise and compact readout for each panel. The initial results of the readout circuit were quantified using a 1-kHz square wave test pulse. The pulse amplitude was chosen to generate approximately the same amount of charges as a 511-keV photon would provide in CZT. The best-case full width at half maximum (FWHM) electronic noise at 511 keV was measured to be 0.69% ± 0.16% (3.52 ± 0.81 in keV units after conversion). The FWHM electronic noise at 511 keV for a complete DAQ chain was 4.33% ± 0.30% (22.13 ± 1.53 in keV units).