Patent ID: 8650014

Claim:
An iterative reconstruction method for updating an input object, the method comprising: providing an initial image object representing radiation from a patient; reconstructing, in a series of iteration steps by a processor, updated image objects, wherein each iteration step includes determining a data model from an input image object, the input image object of a first iteration being the initial image object and the input image objects of subsequent iterations being the updated image objects from previous iterations, and determining a stop-criterion, Q(χ γ 2 ), of the data model on the basis of a chi-square-gamma statistic, χ γ 2 ; determining that the stop-criterion of the data model has remained outside the limitation of a preset threshold value; wherein determining the stop-criterion comprises calculating the chi-square-gamma statistic, χ γ 2 , as a sum of ratios calculated over data points, d j , defining a data space, wherein for each data point a denominator of the ratio is a square of a residual, and the numerator of the ratio is the sum of a measured value of that data point, d j , and a statistical-data-offset number, y, and wherein the residual is the difference between a corrected measured value of that data point and a modeled value, m j , of that data point, wherein the corrected measured value is the sum of the measured value, d j , and the minimum of the measured value and one, Min (d j ,1), the chi-square-gamma statistic, χ γ 2 , calculating represented as: χ γ 2 =Σ( d j +Min( d j ,1)− m j ) 2 /( d j +y ); and wherein determining the stop-criterion, Q(χ γ 2 ), comprises setting the stop-criterion, Q(χ γ 2 ), as a function of a statistical value, A(χ γ 2 ), of the chi-square statistic, χ γ 2 ; and displaying an image of the updated image object from one of the iterations.