Deflection-equipped ct system with non-rectangular detector cells

Abstract

A CT system is constructed to have diagonally oriented perimeter walls of its detector cells. A CT detector comprised of such detector cells has improved spatial coverage (spatial density) and is better equipped for operation with focal spot deflecting x-ray sources. The number of detector channels is also not increased despite the increase in spatial coverage. Moreover, the detector cells can be constructed without much variance from conventional fabrication techniques.

1 . A CT scanner comprising:
 a rotatable gantry;   an x-ray source arranged to project x-rays from the gantry;   an x-ray detector disposed in the gantry generally opposite the x-ray source and having an array of detector cells in which each detector cell has at least one perimeter side that is not perpendicular to two other perimeter sides; and   a data processing unit connected to acquire data from the x-ray detector and programmed to cause at least one of an interpolation of the x-ray detector data or an oversampling of the x-rays projected from the x-ray source.   
     
     
         2 . The scanner of  claim 1  wherein the x-ray source is configured to project a deflecting x-ray beam. 
     
     
         3 . The scanner of  claim 2  wherein a deflection distance of the deflecting x-ray beam is one of ±⅓ of an in-plane width of the detector cells, ±½ of in-plane width of the detector cells, ±⅔ of the in-plane width of the detector cells, and ±¾ 0  of the in-plane width of the detector cells. 
     
     
         4 . The scanner of  claim 2  wherein the data processing unit is further programmed to cause the oversampling of the x-rays by causing a number of acquisitions of x-ray detector data to occur during a projection period of the deflecting x-ray beam. 
     
     
         5 . The scanner of  claim 4  wherein the number of acquisitions is one of 2, 3, or 4 acquisitions. 
     
     
         6 . The scanner of  claim 1  wherein the data processing unit is further programmed to cause the interpolation of the x-ray detector data by averaging data of at least two neighboring detector cells. 
     
     
         7 . The scanner of  claim 1  wherein interpolations of the x-ray detector data and oversamplings of the x-rays create an evenly spaced mapping of data points across an x-direction of the detector. 
     
     
         8 . An x-ray detector comprising:
 an array of x-ray detector cells configured to convert radiation projected from an x-ray source into data signals, each cell having a number of perimeter sides wherein an angle of intersection formed between a pair of the perimeter sides is acute; and   wherein a sampling rate of the array is set for multiple data acquisitions during one projection period of the x-ray source.   
     
     
         9 . The x-ray detector of  claim 8  wherein two perimeter sides of each cell are in parallel with each other and another two perimeter sides of each cell are in parallel with each other. 
     
     
         10 . The x-ray detector of  claim 1  wherein the detector cells of the array are arranged to provide an increased data signal resolution in one of a row direction or a column direction. 
     
     
         11 . A method for implementing an x-ray detection system comprising:
 providing a scintillator array having a number of divisions at a first angle and a number of divisions at a second angle more than 90 degrees from the first angle;   connecting outputs of the scintillator array to a data acquisition system; and   programming the data acquisition system to:
 acquire a matrix of data samples from the scintillator array having a number of values in a column direction and a number of values in a row direction; and 
 augment the matrix of data samples with additional values in the row direction. 
   
     
     
         12 . The method of  claim 11  wherein providing a scintillator array includes providing an array from which an increased number of data values in the column direction may be acquired, as compared to data values acquired from a conventional rectangular scintillator array. 
     
     
         13 . The method of  claim 11  further comprising programming the data acquisition system to determine the additional values non-simultaneously with acquisition of the matrix of data samples. 
     
     
         14 . The method of  claim 11  further comprising programming the data acquisition system to augment the matrix by at least one of interpolating values and oversampling the outputs of the scintillator array. 
     
     
         15 . The method of  claim 11  further comprising disposing the scintillator array in a gantry generally opposite a deflection-capable x-ray source and within a deflection pattern thereof. 
     
     
         16 . A method for acquiring x-ray incidence data comprising:
 projecting deflecting radiation from a x-ray source towards a detector for a given projection period;   sampling a first set of acquisition data from the detector indicative of an incidence of the radiation upon portions of the detector having at least one edge substantially non-parallel to a slice direction and a subject direction; and   integrating other data values with the first set of acquisition data.   
     
     
         17 . The method of  claim 16  wherein integrating the other data values increases the apparent sampling resolution in one of the slice direction and the subject direction. 
     
     
         18 . The method of  claim 16  wherein sampling a first set of acquisition data includes acquiring one of energy integrated values or energy discriminatory values. 
     
     
         19 . The method of  claim 16  further comprising obtaining the other data values by at least one of interpolating the first set of acquisition data and sampling a second set of acquisition data. 
     
     
         20 . The method of  claim 19  wherein sampling the second set of acquisition data occurs during the given projection period. 
     
     
         21 . The method of  claim 16  wherein projecting radiation includes wobbling an x-ray beam between a first position and a second position. 
     
     
         22 . The method of  claim 21  wherein the first position and the second position form a line along one of the slice direction or the subject direction.