Local storage device in high flux semiconductor radiation detectors and methods of operating thereof
A detector element circuit for a CT imaging system may include a plurality of sensors for detecting photons passing through an object and a first electronic component configured to determine an energy of photons detected by the plurality of sensors and generate photon count data, which may be a count of detected photons in one or more energy bins. The detector element circuit may further include a second electronic component configured to receive the photon count data from the first electronic component and is clocked at a first clock rate; a local memory storage configured to receive the photon count data from the second electronic component at the first clock rate and to output the photon count data at a second clock rate.
1. A detector element circuit in a CT imaging system, comprising:
a plurality of radiation sensors for detecting photons attenuated by an object;
a first electronic component configured to determine an energy of photons detected by the plurality of radiation sensors and generate digitized photon count data, wherein the digitized photon count data comprises a digitized count of detected photons in one or more energy bins;
a field programmable gate array (FPGA) configured to receive the digitized photon count data from the first electronic component and generate an output representing the digitized photon count data, wherein the FPGA comprises a FPGA clock configured to control a rate at which the FPGA receives the digitized photon count data from channels of the first electronic component and at which the FPGA outputs the output representing the digitized photon count data; and
a local memory storage configured to receive the output representing the digitized photon count data from the FPGA and comprising a local storage clock configured to control a rate at which the local memory storage generates buffered output data derived from the digitized photon count data,
wherein:
the FPGA clock and the local storage clock are set such that the FPGA is clocked at a first clock rate and the local storage element outputs the buffered output data at a second clock rate; and
the second clock rate and the first clock rate are selected to reduce bottlenecks or data transfer issues imposed by bandwidth limitations between the local memory storage and a computer of the CT imaging system that is configured to receive the buffered output data from the local memory storage.
2. The detector element circuit of claim 1 , wherein the local memory storage is further configured to output the digitized photon count data to an input/output interface at the second clock rate.
3. The detector element circuit of claim 1 , wherein the plurality of radiation sensors comprises a plurality of CZT sensors.
4. The detector element circuit of claim 1 , wherein the second clock rate is slower than the first clock rate.
5. The detector element circuit of claim 1 , wherein the first electronic component is an ASIC.
6. The detector element circuit of claim 1 , wherein the local memory storage buffers the digitized photon count data received from the FPGA.
7. The detector element circuit of claim 1 , wherein the first electronic component is an ASIC, the electronic component is a FPGA, and the plurality of radiation sensors, the ASIC, the FPGA and the local memory storage are mounted on a common support.
8. A CT imaging system, comprising:
a gantry;
a radiation source mounted to the gantry; and
a detector array mounted to the gantry,
wherein:
the detector array is configured to detect radiation emitted from the radiation source and attenuated by an object located in the gantry;
the detector array comprises a plurality of instances of the detector element circuit of claim 1 ; and
the computer is located remotely from the gantry and is configured to receive data buffered by the local memory storage of each detector element circuit.
9. The CT imaging system of claim 8 , wherein the local memory storage in each of the plurality of detector element circuits is clocked at a separate clock rate than other components in the detector element circuit.
10. The CT imaging system of claim 8 , wherein a moving part of the gantry is configured to make a plurality of circular paths relative to the object.
11. The CT imaging system of claim 8 , wherein the radiation sensors and the local memory storage are mounted on a common support, and the common support is mounted to a rotating part of the gantry.
12. A method of operating a CT imaging system, comprising:
detecting photons emitted by an X-ray source and attenuated by an object;
generating digitized photon count data by counting a number of detected photons in a plurality of energy bins;
buffering the digitized photon count data at the first clock rate employing the detector element circuit of claim 1 ; and
outputting the digitized photon count data at the second clock rate from the detector element circuit.
13. The method of claim 12 , wherein a detector array in the CT imaging system detects the photons, and wherein the detector array comprises a plurality of detector element circuits that each include a plurality of radiation sensors.
14. The method of claim 13 , wherein each detector element circuit includes a local memory storage for buffering the digitized photon count data, and each detector element circuit is located on a rotating part of a gantry of the CT imaging system.
15. The method of claim 14 , wherein the local memory storage is clocked at the second clock rate.
16. The method of claim 14 , wherein each detector element circuit includes an electronic component for transferring the digitized photon count data to the local memory storage at the first clock rate.