Imagers in radiation therapy environment

1. A method of performing signal readout in synchronization with operation of a treatment beam source comprising:

reading out a first subset of image signals for an image frame based on radiation received by an imager;

providing a treatment beam pulse; and

reading out a second subset of the image signals for the image frame after the treatment beam source has provided the treatment beam pulse, the second subset of the image signals being different from the first subset of the image signals.

2. The method of claim 1 , wherein the reading out a first subset of image signals is stopped before the step of providing the treatment beam pulse is performed.

3. The method of claim 1 , wherein the first subset of the image signals and the second subset of the image signals are for different respective regions of the image frame.

4. The method of claim 1 , wherein the reading out of a first subset of image signals is performed by a circuit configured to receive image signals.

5. The method of claim 4 , wherein the image signals are generated by an array of imager elements.

6. The method of claim 5 , wherein the array of imager elements generates the image signals based on photon counting.

7. The method of claim 5 , wherein the circuit comprises a readout and control circuit coupled to the array of imager elements, wherein the readout and control circuit is radiation hard.

8. The method of claim 1 , wherein the reading out the second subset of the image signals for the image frame is performed at a pre-determined time or within a predetermined time period with respect to the treatment beam pulse.

9. The method of claim 1 , wherein the providing the treatment beam pulse is performed following a beam hold period.

10. The method of claim 9 , wherein the beam hold period is long enough to allow a reset of the imager, receive imaging dose, and readout some of the image signals.

11. An imaging circuit for use in performing signal readout in synchronization with operation of a treatment beam source, the imaging circuit configured to:

readout a first subset of image signals for an image frame based on radiation received by an imager; and

read out a second subset of the image signals for the image frame after the treatment beam source has provided a treatment beam pulse, the second subset of the image signals being different from the first subset of the image signals.

12. The imaging circuit of claim 11 , wherein the read out a first subset of image signals is stopped before the treatment beam pulse.

13. The imaging circuit of claim 11 , wherein the first subset of the image signals and the second subset of the image signals are for different respective regions of the image frame.

14. The imaging circuit of claim 11 , wherein the imaging circuit is radiation hard.

15. The imaging circuit of claim 11 , wherein the imaging circuit is configured to remain fully functional even after the imager has been exposed to radiation resulting from at least 10 MV radiation beam with parameters of 100 kRad and 600 Mu/min.

16. The imaging circuit of claim 11 , wherein the circuit is configured to withstand at least 100 kRad of radiation.

17. The imaging circuit of claim 11 , wherein the circuit is configured to withstand at least 500 kRad of radiation.

18. The imaging circuit of claim 11 , wherein the readout of the second subset of the image signals for the image frame is performed at a pre-determined time or within a predetermined time period with respect to the treatment beam pulse.

19. The imaging circuit of claim 11 , comprising an edge-less transistor, an enclosed layout transistor (ELT), at least two transistors with guard rings between the two transistors, or any combination of the foregoing.

20. The imaging circuit of claim 11 , comprising a radiation shielding for protecting the circuit from treatment radiation.