Optimized scanning methods and tomography system using region of interest data
A method of scanning parameter optimization, which method may be useful with image-guided radiation therapy (IGRT), allows for controlling exposure of a beam from an x-ray source and/or controlling the detection mechanism for an x-ray detector of imaging radiation of a radiation-delivery device based on one or more parameters of a region of interest of a patient. The one or more parameters of the region of interest may include a dimension, outer contour, density, location relative to an outlet of the beam, location relative to isocenter, location to the whole patient body, etc. Exposure of the patient to the beam may be varied via modulation of one or more scanning parameters for controlling an aspect of the beam and/or the detector to provide for targeted and or reduced radiation exposure of the patient or portion of the patient, and/or for improved quality of guiding images. The modulation may be varied depending on a view angle of the region of interest from a portion of the radiation-delivery device.
1. An imaging method for use with image-guided radiation therapy (IGRT) of a patient, the method comprising:
receiving image data corresponding to a prior image of the patient, wherein the image data includes data corresponding to a region of interest (ROI);
obtaining projection image data of the patient;
performing an image reconstruction based on the obtained projection image data of the patient to obtain a patient image;
registering the prior image with the obtained patient image to obtain a registered image;
identifying the ROI in the registered image;
projecting ROI image data based on the prior image;
generating an optimized set of parameters using the projected ROI image data, the optimized set of parameters optimized to at least one of reduce scan time of a CT scan of the patient, target radiation dose to a particular area of the patient, unformalize dosing to the particular area of the patient, reduce radiation exposure to the patient, reduce radiation exposure to the ROI, reduce x-ray scatter, and improve soft tissue contrast;
performing the CT scan of the patient using said optimized set of parameters.
2. The method of claim 1 , wherein the step of projecting ROI image data is also based on the registered image.
3. The method of claim 1 , wherein the optimized set of parameters comprises data for modulation of tube current when imaging the patient.
4. The method of claim 1 , wherein the optimized set of parameters comprises data for adjusting tube potential when imaging the patient.
5. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to scan speed when imaging the patient.
6. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to detector gain.
7. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to detector binning.
8. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to at least one of a focal spot of an imaging beam, an imaging beam width, a helical pitch of an imaging scan, or a detector readout section size during imaging.
9. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to radiographic contrast for various areas of the patient's body.
10. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to thickness or material of an imaging beam filter.
11. The method of claim 1 , wherein the optimized set of parameters comprises data corresponding to x-ray dosage of the imaging beam.