Fast, Low-Noise Readout Chip for Avalanche Photodiode Arrays for Use in Positron-Emission Tomography Imaging

60513 Breast cancer is one of the major public health concerns today in the United States. However, the detection of breast cancer through mammographic screening is complicated by various anatomic factors that can hide or simulate tumors, leading to reduced sensitivity and specificity of mammography. Consequently, the rate of false negatives is 5%-6%, which results in loss of lives. The accuracy of mammography can be improved by complementing it with functional imaging techniques such as PET imaging. This will require dedicated breast imaging PET scanners. A high-resolution breast imaging PET scanner, consisting of LSO (lutetium silicate) scintillator crystals read out by avalanche photodiode (APD) arrays, is currently under development. This project will develop a fast, low-noise integrated front-end chip (ASIC) for this scanner, specifically designed to read out the APD signals with high accuracy and low random background. During Phase I, the feasibility of the proposed readout chip was demonstrated by designing, simulating, building, and testing discrete prototypes of the critical parts of the proposed chip (ASIC). A preliminary design for the core parts of the readout chip was developed. Phase II will finalize the chip design, create its silicon layout, and fabricate prototype chips. Using these chips, prototype multi-channel LSO/APD/ASIC detector modules will be designed and built, and their performance will be evaluated for PET applications. Commercial Applications and Other Benefits as described by the awardee: In addition to breast imaging, the proposed chip (ASIC) should be useful for any applications that require reading out APDs or multianode photomultipliertubes with fast and highly accurate timing. This includes other PET imaging applications, such as animal PET. Other applications include astrophysics, nuclear physics, and high-energy physics research, such as Compton scatter imaging detectors.