Cone beam scanner using oblique surface reconstructions

摘要

Data collected from a cone beam scanner is reconstructed into a volumetric image representation by defining a plurality of oblique surfaces (44) which are reconstructed into a reconstruction cylinder (C). An interpolator (52) identifies non-redundant rays of radiation which pass through the oblique surfaces. More particularly, rays of radiation that intersect a center point of each oblique surface (70) are identified along with rays tangent to surface rings on each oblique surface (72, 74). Data from the identified non-redundant rays of radiation is weighted by a first data processor (54). A second data processor (56) convolves the weighted data and passes it to a backprojector (58) which backprojects the data into an image memory (60). The oblique surface reconstruction technique facilitates the use of conventional two-dimensional convolution and backprojection techniques that enjoy relative computational simplicity and efficiency as well as three-dimensional reconstruction techniques that use a minimum number of projections. In addition, the oblique surface reconstruction technique facilitates accurate reconstruction of cone beam projections with over ten times the area of current multi-ring scanners.