Image reconstruction using data ordering

Abstract

Methods, systems and apparatuses for processing data associated with nuclear medical imaging techniques are provided. Data is ordered in LUT's and memory structures. Articles of manufacture are provided for causing computers to carry out aspects of the invention. Data elements are ordered into a plurality of ordered data groups according to a spatial index order, and fetched and processed in the spatial index order. The data elements include sensitivity matrix elements, PET annihilation event data, and system and image matrix elements, the data grouped in orders corresponding to their processing. In one aspect geometric symmetry of a PET scanner FOV is used in ordering the data and processing. In one aspect a system matrix LUT comprises total number of system matrix elements equal to a total number of image matrix elements divided by a total number of possible third index values.

What is claimed is: 
     
         1 . A system, comprising:
 a memory containing an ordered LUT comprising a plurality of data elements ordered relative to a geometric index in a spatial index order; and   a processor;   wherein the processor is configured to fetch each of a plurality of data elements from the LUT and process each of the plurality of data elements in the spatial index order.   
     
     
         2 . The system of  claim 1 , wherein the plurality of data elements is a plurality of system matrix elements;
 wherein the processor is a reconstructor; and   wherein the reconstructor is configured to fetch each of a plurality of system matrix elements from the LUT and generate volumetric data responsive to data indicative of emission events in an object under examination by processing each of an ordered group of image matrix elements with the system matrix element in an image matrix update order, the image matrix update order common with an order of storage of the image matrix elements in the memory.   
     
     
         3 . The system of  claim 2  wherein the LUT comprises a total number of system matrix elements, the total number of system matrix elements equal to a total number of image matrix elements divided by a total number of possible geometric index values. 
     
     
         4 . The system of  2 , wherein the reconstructor is configured to loop sequentially through all azimuthal angle value indices of the system matrix elements. 
     
     
         5 . The system of  claim 2 , further comprising:
 an array of PET detector means spaced along an axial PET scanner axis for obtaining the data indicative of emission events in an object under examination, wherein the ordered system element matrix LUT and the ordered image element matrix are ordered in common with the axially spaced array; and   means for generating a human readable image indicative of the corrected data.   
     
     
         6 . A LUT comprising a plurality of system matrix elements ordered in alignment with a PET scanner detector crystal spacing along an axial axis. 
     
     
         7 . The LUT of  claim 6 , further comprising a total number of system matrix data elements, the total number a function of a number of radial data bins; a number of LOR azimuthal angles; and a number of PET scanner axial detector rings. 
     
     
         8 . The LUT of  claim 7 , wherein the total number of system matrix elements is equal to a total number of image matrix elements divided by a total number of possible axial axis index values. 
     
     
         9 . The LUT of  claim 6 , wherein the LUT is configured for use in reconstruction of PET data into a volumetric image by a reconstructor, wherein the reconstructor is configured to:
 fetch a system matrix element having a first and second index value from the LUT into a cache; and   generate an image estimate update by updating each of a plurality of image matrix elements fetched into the cache with the system matrix element, each of the plurality of image matrix elements having the first and second index values and divergent axial axis index values.   
     
     
         10 . A LUT comprising a plurality of data elements ordered in correlation to the processing of the data elements by a processor, wherein a first LUT data element fetched into a memory device for a first plurality of sequentially ordered data element operations by the processor is located in the LUT next to a second LUT data element fetched for an immediately subsequent second plurality of sequentially ordered data element operations. 
     
     
         11 . The LUT of  claim 10 , wherein the processor is a PET scanner reconstructor;
 wherein the plurality of data elements is a plurality of system matrix elements ordered in correlation to the processing of the system matrix elements by the reconstructor;   wherein the first plurality of sequentially ordered data element operations comprises generating volumetric data responsive to data indicative of emission events in an object under examination by processing a first ordered group of image matrix elements with the first system matrix element in an image matrix update order, the image matrix update order common with an order of storage of the first ordered group of image matrix elements in the memory; and   wherein the second plurality of sequentially ordered data element operations comprises generating volumetric data responsive to data indicative of emission events in an object under examination by processing a second ordered group of image matrix elements with the second system matrix element in the image matrix update order, the image matrix update order common with an order of storage of the second ordered group of image matrix elements in the memory.   
     
     
         12 . The LUT of  claim 10 , wherein the LUT comprises a total number of system matrix elements, the total number of system matrix elements equal to a total number of image matrix elements divided by a total number of possible values of an image matrix axial index. 
     
     
         13 . A positron imaging apparatus, comprising:
 an array of detector means spaced along an axial scanner axis for obtaining data indicative of emission events in an object under examination;   a memory containing a LUT, the LUT comprising a plurality of system matrix elements ordered in correlation with the axially spaced array;   a reconstructor means for reconstructing the obtained data to generate volumetric data by using the system matrix elements; and   means for generating a human readable image indicative of the corrected data.   
     
     
         14 . The apparatus of  claim 13 , further comprising a cache, wherein the reconstructor means is configured to fetch a system element with a first index value and a second index value from the LUT into the cache;
 the reconstructor means is further configured to fetch a plurality of image matrix elements, each of the plurality of image matrix elements having the first and second index value in common and divergent third index values, into the cache; and   the reconstructor means is further configured to update the fetched plurality of image matrix elements with the fetched system matrix element.   
     
     
         15 . An article of manufacture comprising a computer usable medium having a computer readable program embodied in said medium, wherein the computer readable program, when executed on a computer, causes the computer to:
 fetch an ordered data group into a memory device, the ordered data group comprising an ordered plurality of data elements ordered having common first and second index values and a divergent third index value; and   process each data element of the ordered data group from the memory device in a processing order, the processing order comprising the order of the plurality of data elements in the ordered data group.   
     
     
         16 . The article of manufacture of  claim 15 , wherein the computer readable program, when executed on a computer, causes the computer to generate an image estimate update by processing each data element of the ordered data group from the memory device in the processing order. 
     
     
         17 . The article of manufacture of  claim 15 , wherein the computer readable program, when executed on the computer, causes the computer to order the ordered data group by using a geometric symmetry of a PET scanner FOV. 
     
     
         18 . The article of manufacture of  claim 15 , wherein the computer readable program, when executed on the computer, causes the computer to order the ordered data group according to an axial spacing dimension of PET scanner detector crystals. 
     
     
         19 . The article of manufacture of  claim 15 , wherein the computer readable program, when executed on the computer, causes the computer to fetch the ordered data group into a cache memory device from a system memory resource;
 wherein the data elements are each image matrix elements;   wherein the ordered data group comprises image matrix elements having the same transverse indices but a different axial index;   wherein the order of the plurality of data elements in the ordered data group is an ascending or descending axial index order; and   wherein the processing order comprises processing the image matrix elements in the ascending or descending axial index order.