Detecting motion by using a low dose x-ray image

1. A method comprising:

generating a reference image of a patient;

generating a subsequent x-ray image of the patient after the generating of the reference image, the subsequent x-ray image being associated with a low dosage;

determining, by a processing device, a difference between the reference image and the subsequent x-ray image that is associated with the low dosage; and

identifying whether a motion of the patient has occurred based on the determined difference.

2. The method of claim 1 , further comprising:

in response to identifying that the motion of the patient has occurred, generating a motion x-ray image that is associated with a second dosage that is higher than the low dosage associated with the subsequent x-ray image;

performing image registration between the reference image and the motion x-ray image to estimate an amount of the motion of the patient that has occurred; and

modifying a medical procedure for the patient based on the amount of the motion of the patient that has occurred.

3. The method of claim 1 , wherein identifying whether the motion of the patient has occurred comprises:

determining a similarity value between the reference image and the subsequent x-ray image based on a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage, the motion being identified as occurring when the similarity value exceeds a threshold value and the motion not being identified as occurring when the similarity value does not exceed the threshold value.

4. The method of claim 1 , wherein determining the difference between the reference image and the subsequent x-ray image comprises:

determining a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage; and

normalizing pixel values of the subsequent x-ray image with the reference image, the normalizing of the pixel values being based on changing pixel values of the subsequent x-ray image or the reference image based on a distribution of pixel values of the reference image or the subsequent x-ray image.

5. The method of claim 1 , wherein determining the difference between the reference image and the subsequent x-ray image comprises:

determining a first gantry angle for the reference image and a second gantry angle for the subsequent x-ray image;

generating a first digitally reconstructed radiograph (DRR) for the reference image based on the first gantry angle;

generating a second DRR for the subsequent x-ray image based on the second gantry angle;

generating a similarity map corresponding to similar regions between the first DRR and the second DRR;

computing a similarity value by comparing the similarity map to the subsequent x-ray image; and

identifying whether the motion of the patient has occurred based on comparing the similarity value to a similarity threshold.

6. The method of claim 1 , wherein determining the difference between the reference image and the subsequent x-ray image comprises:

determining a first gantry angle for the reference image and a second gantry angle for the subsequent x-ray image;

determining, based on the first gantry angle and the second gantry angle, an expected position of a fiducial in the subsequent x-ray image;

computing a similarity value by identifying an image patch from the reference image including the fiducials and searching for similar image patches in the subsequent x-ray image; and

identifying whether the motion of the patient has occurred based on comparing the similarity value to a similarity threshold.

7. The method of claim 2 , wherein the reference image, the subsequent x-ray image, and the motion x-ray image are generated by an x-ray imaging source of a helical radiation delivery system or by one or more x-ray imaging sources at different positions with respect to the patient.

8. The method of claim 1 , further comprising:

in response to identifying that the motion of the patient has not occurred, generating another subsequent x-ray image that is associated with the low dosage at a time period after generating the subsequent x-ray image.

9. The method of claim 1 , further comprising:

performing a tracking operation associated with the patient based on identifying that the motion of the patient has occurred to modify a radiation treatment delivery for the patient.

10. The method of claim 1 , wherein the reference image is an x-ray image.

11. The method of claim 1 , wherein the reference image is a digitally reconstructed radiograph.

12. The method of claim 1 , wherein the reference image and the subsequent x-ray image being from nearby beam positions corresponding to known movement of a treatment couch or an imaging gantry.

13. A system comprising:

a memory;

a motion sensor; and

a processing device, operatively coupled with the memory, to:

receive a reference image of a patient from the motion sensor;

receive a subsequent x-ray image of the patient from the motion sensor after the receiving of the reference image, the subsequent x-ray image being associated with a low dosage;

determine a difference between the reference image and the subsequent x-ray image that is associated with the low dosage; and

identify whether a motion of the patient has occurred based on the determined difference.

14. The system of claim 13 , wherein the processing device is further to:

in response to identifying that the motion of the patient has occurred, generate a motion x-ray image that is associated with a second dosage that is higher than the low dosage associated with the subsequent x-ray image;

perform image registration between the reference image and the motion x-ray image to estimate an amount of the motion of the patient that has occurred; and

modify a medical procedure for the patient based on the amount of the motion of the patient that has occurred.

15. The system of claim 13 , wherein to identify whether the motion of the patient has occurred, the processing device is further to:

determine a similarity value between the reference image and the subsequent x-ray image based on a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage, the motion being identified as occurring when the similarity value exceeds a threshold value and the motion not being identified as occurring when the similarity value does not exceed the threshold value.

16. The system of claim 13 , wherein to determine the difference between the reference image and the subsequent x-ray image, the processing device is further to:

determine a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage; and

normalize pixel values of the subsequent x-ray image with the reference image, the normalizing of the pixel values being based on changing pixel values of the subsequent x-ray image or the reference image based on a distribution of pixel values of the reference image or the subsequent x-ray image.

17. The system of claim 14 , wherein the reference image, the subsequent x-ray image, and the motion x-ray image are generated by an x-ray imaging source of a helical radiation delivery system or by one or more x-ray imaging sources at different positions with respect to the patient.

18. The system of claim 13 , wherein the processing device is further to:

in response to identifying that the motion of the patient has not occurred, generate another subsequent x-ray image that is associated with the low dosage at a time period after generating the subsequent x-ray image.

19. The system of claim 13 , wherein the processing device is further to:

perform a tracking operation associated with the patient based on identifying that the motion of the patient has occurred to modify a radiation treatment delivery for the patient.

20. A non-transitory computer readable medium comprising instructions that, when executed by a processing device, cause the processing device to:

generate a reference image of a patient;

generate a subsequent x-ray image of the patient after the generating of the reference image, the subsequent x-ray image being associated with a low dosage;

determine, by the processing device, a difference between the reference image and the subsequent x-ray image that is associated with the low dosage; and

identify whether a motion of the patient has occurred based on the determined difference.

21. The non-transitory computer readable medium of claim 20 , wherein the processing device is further to:

in response to identifying that the motion of the patient has occurred, generate a motion x-ray image that is associated with a second dosage that is higher than the low dosage associated with the subsequent x-ray image;

perform image registration between the reference image and the motion x-ray image to estimate an amount of the motion of the patient that has occurred; and

modify a medical procedure for the patient based on the amount of the motion of the patient that has occurred.

22. The non-transitory computer readable medium of claim 20 , wherein to identify whether the motion of the patient has occurred, the processing device is further to:

determine a similarity value between the reference image and the subsequent x-ray image based on a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage, the motion being identified as occurring when the similarity value exceeds a threshold value and the motion not being identified as occurring when the similarity value does not exceed the threshold value.

23. The non-transitory computer readable medium of claim 20 , wherein to determine the difference between the reference image and the subsequent x-ray image, the processing device is further to:

determine a difference in pixel values between the reference image and the subsequent x-ray image that is associated with the low dosage; and

normalize pixel values of the subsequent x-ray image with the reference image, the normalizing of the pixel values being based on changing pixel values of the subsequent x-ray image or the reference image based on a distribution of pixel values of the reference image or the subsequent x-ray image.

24. The non-transitory computer readable medium of claim 21 , wherein the reference image, the subsequent x-ray image, and the motion x-ray image are generated by an x-ray imaging source of a helical radiation delivery system or by one or more x-ray imaging sources at different positions with respect to the patient.

25. The non-transitory computer readable medium of claim 20 , wherein the processing device is further to:

in response to identifying that the motion of the patient has not occurred, generate another subsequent x-ray image that is associated with the low dosage at a time period after generating the subsequent x-ray image.

26. The non-transitory computer readable medium of claim 20 , wherein the reference image and the subsequent x-ray image being from nearby beam positions corresponding to know movement of a treatment couch or an imaging gantry.