Readout electronics architecture with improved timing resolution

A method of interfacing with an array of photodetectors in a positron emission tomography (PET) imaging system, comprising:

• receiving analog signals from each photodetector in the array of photodetectors using a front-end circuit, wherein the front-end circuit is coupled to a respective cathode of each photodetector in the array of photodetectors;
• generating a hit signal for timing pickoff based on a signal summing the analog signals from the array of photodetectors using a time discriminating unit comprising a low input impedance amplifier that receives the signal summing the analog signals;
• generating a summed energy output signal based on each of the analog signals using an energy circuit operably coupled to the front-end circuit, the summed energy output signal representing an energy level of the detected radiation in the array of photodetectors;
• and
• generating a summed positional output signal based on each of the analog signals using the energy circuit, the positional output signal representing a location of the detected radiation in the array of photodetectors.

A multichannel application specific integrated circuit (ASIC) for interfacing with an array of photodetectors in a positron emission tomography (PET) imaging system, the ASIC comprising:

• a front-end circuit configured to be capacitive coupled to each photodetector of the array of photodetectors and to receive analog signals therefrom, wherein the front-end circuit is coupled to a respective cathode of each photodetector in the array of photodetectors;
• a time discriminating circuit comprising a low input impedance amplifier configured both to be conductively coupled to each photodetector of the array of photodetectors and to receive a signal summing the analog signals from the array of photodetectors and the time discriminating circuit is configured to generate a hit signal for timing pickoff based on the signal, wherein the low input impedance amplifier has an input impedance of 1 Ohm or less;
• and
• an energy circuit operably coupled to the front-end circuit and configured to generate a summed energy output signal based on each of the analog signals and summed positional output signal based on each of the analog signals, the summed energy output signal representing an energy level of the detected radiation in the array of photodetectors, and the summed positional output signal representing a location of the detected radiation in the array of photodetectors.