System and method for compensating temperature gain variation in radiation detectors

A method for calibrating gain in a radiation detector, comprising the acts of:

• measuring a dark current generated by each silicon photomultiplier of an imaging detector comprising an array of silicon photomultipliers;
• determining a respective bias voltage as a function of the measured dark current required to maintain a constant over voltage for each silicon photomultiplier;
• and
• applying the bias voltage to each silicon photomultiplier.

An imaging system, comprising:

• an imaging detector comprising a plurality of silicon photomultipliers, wherein each silicon photomultiplier comprises an array of microcells;
• control circuitry configured to apply a bias voltage to the microcells of each silicon photomultiplier, wherein the control circuitry is configured to independently set the bias voltage applied to each silicon photomultiplier so as to maintain a constant over voltage, and wherein the bias voltage needed to obtain the constant over voltage is determined at least in part based on a respective dark current periodically generated by each respective silicon photomultiplier;
• image reconstruction and processing circuitry configured to generate images based on output signals acquired from the detector panel;
• and
• at least one image display workstation configured to display the images.

A method for determining a change in temperature at a radiation detector, comprising the acts of:

• measuring a dark current generated by each silicon photomultiplier of an imaging detector comprising an array of silicon photomultipliers;
• determining a ratio of the dark current relative to a calibration dark current;
• and
• determining a temperature difference based on the ratio, wherein the temperature difference corresponds to the difference between the temperature when the calibration dark current was determined and when the dark current was measured.