Method for computing patient radiation dose in computed tomography

1. A method for determining a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

subjecting a patient to an x-ray beam from an x-ray source;

determining a primary x-ray radiation dose from the x-ray beam;

determining a scattered x-ray radiation dose from the x-ray beam;

inputting properties from the x-ray source;

wherein determining the primary x-ray radiation dose comprises calculating a primary dose distribution from CT scan image data generated during the CT scan of the patient; and

calculating a radiation dose delivered to the patient based on the primary x-ray radiation dose and scattered x-ray radiation dose;

wherein said properties are used to calculate the primary dose distribution;

wherein one of said properties comprises a mA modulation scheme of the x-ray source;

wherein the mA modulation scheme is used to compute the radiation dose delivered to the patient.

2. A method as recited in claim 1 :

wherein the primary x-ray radiation dose comprises the deposition of energy in the patient from x-ray photons which have their original trajectory from the x-ray source; and

wherein the scattered x-ray radiation dose comprises the deposition of energy in tissues from x-ray photons which have been scattered within the patient and out of line from their original trajectory from the x-ray source.

3. A method as recited in claim 1 , wherein the CT scan image data is scaled down prior to calculating the primary dose distribution.

4. A method as recited in claim 1 ; wherein the mA modulation scheme is derived from the CT scan image data to compute the radiation dose delivered to the patient.

5. A method as recited in claim 1 , wherein determining the scattered x-ray radiation dose comprises calculating a scattered dose distribution from the CT scan image data and the primary dose distribution.

6. A method as recited in claim 1 , further comprising:

generating a CT dose distribution map from the calculated radiation dose;

wherein the CT dose distribution map correlates to the CT scan image data.

7. A method as recited in claim 1 , wherein reconstruction software and hardware of the x-ray source is used to calculate the radiation dose.

8. A method for determining a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

subjecting a patient to an x-ray beam from an x-ray source;

determining a primary x-ray radiation dose from the x-ray beam;

determining a scattered x-ray radiation dose from the x-ray beam;

calculating a radiation dose delivered to the patient based on the primary x-ray radiation dose and scattered x-ray radiation dose;

wherein determining the primary x-ray radiation dose comprises calculating a primary dose distribution from CT scan image data generated during the CT scan of the patient; and wherein determining the scattered x-ray radiation dose comprises calculating a scattered dose distribution from the CT scan image data and the primary dose distribution; and

determining a secondary scattered x-ray radiation dose from the scattered dose distribution and the CT scan image data.

9. A method for determining a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

subjecting a patient to an x-ray beam from an x-ray source;

determining a primary x-ray radiation dose from the x-ray beam;

determining a scattered x-ray radiation dose from the x-ray beam;

calculating a radiation dose delivered to the patient based on the primary x-ray radiation dose and scattered x-ray radiation dose; comprising:

determining a boundary of an organ of the patient; and

calculating an average radiation dose delivered to the organ based on the determined boundary and the calculated radiation dose.

10. A method as recited in claim 9 , further comprising:

applying a weight factor to the average dose to calculate an effective dose to the organ.

11. A method as recited in claim 10 , further comprising:

including one or more of the radiation dose, average radiation dose, or effective dose as part of a DICOM header for a CT image of the patient.

12. A method for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

generating a CT image dataset of a region of the patient;

determining one or more parameters relating to a x-ray source used to generate the CT image dataset; and

calculating the radiation dose delivered to the patient as a function of the CT image data set and the one or more parameters of the x-ray source;

wherein determining one or more parameters comprises determining a mA modulation scheme of the x-ray source.

13. A method as recited in claim 12 , wherein calculating the radiation dose delivered to the patient comprises:

calculating a primary x-ray dose distribution from the CT image dataset;

calculating a scattered x-ray dose distribution from the CT image dataset; and

calculating the radiation dose delivered to the patient based on said primary x-ray dose distribution and scattered x-ray dose distribution.

14. A method as recited in claim 13 , wherein the mA modulation scheme is derived from the CT image dataset.

15. A method as recited in claim 13 , wherein the scattered x-ray dose distribution is calculated as a function of the CT image dataset and the primary x-ray dose distribution.

16. A method as recited in claim 12 , wherein the CT image dataset is scaled down prior to calculating the radiation dose.

17. A method as recited in claim 12 , further comprising: calculating an average radiation dose for a specific CT image in the CT image dataset.

18. A method as recited in claim 17 , further comprising:

including average radiation dose for a specific CT image in a DICOM header of the CT image.

19. A method as recited in claim 12 , further comprising:

generating a CT dose distribution map from the calculated radiation dose;

wherein the CT dose distribution map correlates to the CT image dataset.

20. A method for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

generating a CT image dataset of a region of the patient;

determining one or more parameters relating to a x-ray source used to generate the CT image dataset;

calculating the radiation dose delivered to the patient as a function of the CT image data set and the one or more parameters of the x-ray source;

wherein calculating the radiation dose delivered to the patient comprises:

calculating a primary x-ray dose distribution from the CT image dataset;

calculating a scattered x-ray dose distribution from the CT image dataset; and

calculating the radiation dose delivered to the patient based on said primary x-ray dose distribution and scattered x-ray dose distribution; and

determining a secondary scattered x-ray dose distribution from the scattered x-ray dose distribution and the CT image dataset.

21. A method for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

generating a CT image dataset of a region of the patient;

determining one or more parameters relating to a x-ray source used to generate the CT image dataset;

calculating the radiation dose delivered to the patient as a function of the CT image data set and the one or more parameters of the x-ray source;

determining a boundary of an organ of the patient; and

calculating an average radiation dose delivered to the organ based on the determined boundary and the calculated radiation dose.

22. A method as recited in claim 21 , further comprising: applying a weight factor to the average dose to calculate an effective dose to the organ.

23. A method as recited in claim 22 , further comprising:

including one or more of the radiation dose, average radiation dose, or effective dose as part of a DICOM header for a CT image of the CT image dataset.

24. A method for computing a radiation dose delivered to a patient during a computed tomography (CT) scan of the patient, comprising:

generating a CT image dataset of a region of the patient;

determining one or more parameters relating to a x-ray source used to generate the CT image dataset;

calculating a primary x-ray dose distribution as a function of the CT image dataset and the one or more parameters relating to a x-ray source;

calculating a scattered x-ray dose distribution as a function of the primary x-ray dose distribution;

computing the radiation dose delivered to the patient based on the primary x-ray dose distribution and scattered x-ray dose distribution;

determining a boundary of an organ of the patient; and

calculating an average radiation dose delivered to the organ based on the determined boundary and the calculated radiation dose.

25. A method as recited in claim 24 , further comprising:

calculating an average radiation dose for a specific CT image in the CT image dataset.

26. A method as recited in claim 25 , further comprising:

including the average radiation dose for a specific CT image in a DICOM header of the CT image.

27. A method as recited in claim 24 , further comprising:

applying a weight factor to the average dose to calculate an effective dose to the organ.

28. A method as recited in claim 24 , wherein the average radiation dose is calculated for one or more of the following anatomical features: fetal dose, eye orbit dose, thyroid dose, bones, blood forming elements, spleen, liver, bladder, brain, gonads, breast, pancreas, kidney, adrenal.

29. A method as recited in claim 24 , further comprising:

determining a boundary of a pathological entity of the patient; and

calculating an average radiation dose delivered to the pathological entity based on the determined boundary and the calculated radiation dose.

30. A method as recited in claim 24 , further comprising:

determining a boundary of a man-made entity in the patient; and

calculating an average radiation dose delivered to the man-made entity based on the determined boundary and the calculated radiation dose.

31. A method as recited in claim 24 , further comprising:

computing an external radiation dose delivered to the patient outside the scanned volume of the CT dataset by extrapolating the computed radiation dose to other regions of the patient's body.