| 摘要 |
An x-ray system comprising an x-ray source, a single essentially round collimator, a camera, a detector and a monitor, means for moving the collimator in a plane generally parallel to the plane of the collimator; and the collimator comprising a central aperture that allows all the radiation to pass through, an outer annulus that reduces the radiation passing through at an amount depending on the material and the thickness of the material and an inner annulus between the central aperture and the outer annulus, with thickness changing as a function of the distance from the center, starting at thickness zero on the side of the central aperture and ending at the thickness of the outer annulus on the side of the outer annulus. |
| 主权项 |
1. An x-ray system comprising an x-ray source, a single essentially round collimator, a detector, a monitor and means for moving said collimator in a plane generally parallel to the plane of said collimator; said collimator comprising an aperture that allows all the radiation to pass through, an outer annulus that reduces the radiation passing through at an amount depending on the material and the thickness of the material and an inner annulus between said aperture and said outer annulus, with thickness changing as a function of the distance from the aperture, starting at thickness zero on the side of the aperture and ending at the thickness of the outer annulus on the side of the outer annulus;
said detector configured to capture x-ray radiation, said system additionally configured to read a frame comprising pixels from said detector after each frame capture by the detector; the system further configured to calculate gain and offset correction for each frame; the system further configured to calculate normalization factors for each frame, resulting from the different radiation DPP (dose per pixel) in each of said aperture, said outer annulus and said inner annulus of the collimator. |
