Patent ID: 7394927
Filing Date: 2008-07-01
Classification: G06T

Abstract:
1. An iterative method of determining a spatial distribution of values (μ j ) of a property of an object, and particularly values of its absorption, in an examination region, starting from measured values (p l ) that are first acquired with a measuring device, and particularly with a computer tomograph, wherein the measured values (p l ) can each be represented as a sum of values (μ j ) of a property that have each been multiplied by a proportional factor (A lj ), which measured values are divided into groups, and wherein the proportional factor (A lj ) is a measure of the proportion that a value (μ j ) of the property forms of the measured value (p l ), and each value (μ j ) of the property is approached by one iteration value (μ j k ) at a time by setting each iteration value (μ j k ) to a starting value and performing the following steps at least once on each group of measured values (p l ) until a stop criterion is satisfied: a) generating a reference measured value for each measured value (p b) generating a measured value difference for each measured value (p c) for each measured value (p d) dividing each measured value difference that has been multiplied by the reliability parameter (λ e) updating the distribution by backward projection of the measured value differences obtained in step d) into the examination region.