Integrated automatic exposure control for portal imaging in radiotherapy
AssigneeSiemens Medical Systems, Inc.
InventorsWilliam F. Collins, Francis Cheng
Life of this patent
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Abstract
Method and system aspects for integrated automatic exposure control for portal imaging in radiotherapy are described. In an exemplary method aspect, the method includes controlling scanning and blanking of a target of a camera pick-up tube to capture an initial image, and analyzing the initial image to establish an initial image intensity. The method further includes utilizing the initial image intensity to determine a time for scanning a next image, and combining a scan of the next image with the initial image to produce a portal image with a maximized signal to noise ratio.
Claims20
A method for integrated automatic exposure control for portal imaging in radiotherapy, the method comprising:
- controlling scanning and blanking of a target of a camera pick-up tube to capture an initial image;
- analyzing the initial image to establish an initial image intensity;
- utilizing the initial image intensity to determine a time for scanning a next image;
- and
- combining a scan of the next image with the initial image to produce a portal image with a maximized signal to noise ratio.
An integrated system for automatic exposure control for portal image capture during radiation therapy to maximize a signal to noise ratio in the portal image, the system comprising:
- a radiotherapy machine for delivering radiation to a treatment area and including an integrated portal imager for capturing a portal image of the treatment area and including a control unit and a camera with a camera pick-up tube;
- and
- a computer coupled to the radiotherapy machine and the control unit, the computer for signalling the control unit to control scanning and blanking of a target of the camera pick-up tube to capture an initial image, for analyzing the initial image from the camera to establish an initial image intensity, for utilizing the initial image intensity to determine a time for scanning a next image, and for combining a scan of the next image with the initial image to produce the portal image with a maximized signal to noise ratio.
A computer readable medium containing program instructions for a process of integrated automatic exposure control for portal imaging in radiotherapy comprising:
- blanking scanning of a camera pick-up tube for a predetermined time period;
- scanning an image for one frame at the end of the predetermined time period;
- blanking scanning;
- converting the one frame into a sample digital image for transfer into memory;
- analyzing the sample digital image to determine an initial image intensity;
- comparing the initial image intensity with a pre-selected nominal intensity;
- determining a time for performing a next image scan;
- generating a next image at the time of the next image scan;
- and
- displaying a nominal portal image from a combination of the image and the next image.
Dependencies are inferred from the claim text.