Method for optimizing radiation beam intensity profile shape using dual multiple aperture devices

Abstract

The present invention is directed to multiple aperture devices (MADs) for beam shaping in x-ray imaging. Two or more of these binary filters can be placed in an x-ray beam in series to permit a large number of x-ray fluence profiles. However, the relationship between particular MAD designs and the achievable fluence patterns is complex. The present invention includes mathematical and physical models that are used within an optimization framework to find optimal MAD designs. Specifically, given a set of target fluence patterns, the present invention finds, for example, a dual MAD design that is a “best fit” in generating the desired fluence patterns. This process provides a solution for both the design of MAD filters as well as the control actuation that is required (relative motion between MADs) that needs to be specified as part of the operation of a MAD-based fluence field modulation system.

What is claimed is: 
     
         1 . A device for beam shaping in imaging comprising:
 two or more multiple aperture devices placed in series, wherein each of the multiple aperture devices have a design and each of the multiple aperture devices are configured to have motion relative to others of the multiple aperture devices; and   wherein the design and the motion of the multiple aperture devices is predetermined to generate a predetermined fluence pattern or the motion of the multiple aperture devices is determined on-the-fly to generate a fluence pattern.   
     
     
         2 . The device of  claim 1  wherein the design and relative motion are chosen using mathematical models. 
     
     
         3 . The device of  claim 1  wherein the design and relative motion are chosen using physical models. 
     
     
         4 . The device of  claim 1  wherein the design and relative motion are chosen using mathematical and physical models. 
     
     
         5 . The device of  claim 1  wherein the predetermined fluence pattern is based on a single target object. 
     
     
         6 . The device of  claim 1  wherein the predetermine fluence pattern is based on a group of target objects. 
     
     
         7 . The device of  claim 1  wherein the multiple aperture device comprises bars. 
     
     
         8 . The device of  claim 7  further comprising design characteristics taking the form of thickness of each bar. 
     
     
         9 . The device of  claim 7  further comprising design characteristics taking the form of position of each bar relative to one another. 
     
     
         10 . The device of  claim 7  further comprising design characteristics taking the form of the frequency of the bars. 
     
     
         11 . A method for beam shaping in imaging comprising:
 placing two or more multiple aperture devices in series, wherein each of the multiple aperture devices have a design and each of the multiple aperture devices are configured to have motion relative to others of the multiple aperture devices; and   generating a fluence pattern.   
     
     
         12 . The method of  claim 11  further comprising predetermining the design and the motion of the multiple aperture devices to generate a predetermined fluence pattern. 
     
     
         13 . The method of  claim 11  further comprising determining the motion of the multiple aperture devices on-the-fly to generate a fluence pattern. 
     
     
         14 . The method of  claim 11  further comprising programming the design and relative motion with one chosen from a group consisting of using mathematical models, physical models, or a combination of the two. 
     
     
         15 . The method of  claim 11  further comprising basing the predetermined fluence pattern on a single target object. 
     
     
         16 . The method of  claim 11  further comprising basing predetermine fluence pattern on a group of target objects. 
     
     
         17 . The method of  claim 11  further comprising the multiple aperture device comprising bars. 
     
     
         18 . The method of  claim 11  further comprising design characteristics taking the form of thickness of each bar. 
     
     
         19 . The method of  claim 11  further comprising design characteristics taking the form of position of each bar relative to one another. 
     
     
         20 . The method of  claim 11  further comprising design characteristics taking the form of the frequency of the bars.