A computer implemented method of artifact correction in a data set of an object of interest, the method comprising the step of: reconstructing (S6) an image of the object of interest on the basis of the data set; wherein a statistical weighing is performed during reconstruction of the image, wherein the data set is a projection data set acquired by means of a source of electromagnetic radiation generating a beam and by means of a radiation detector detecting the beam, wherein the reconstruction of the image is performed on the basis of an iterative algorithm comprising a plurality of update steps until an end criterion has been fulfilled, and determining a number of detected photons Y i during acquisition of the data set; wherein the weighing is based on an intrinsic statistical error σ Y i of the number of detected photons Y i , wherein each update step comprises subtractions weighted with the intrinsic statistical error σ Y i , based on the number of detected photons Y i , during reconstruction of the image, wherein σ Y i , is the square root of Y i , wherein each update is a result of a respective cycle of the iterative algorithm, wherein the iterative algorithm is a maximum likelihood algorithm; wherein the reconstructed image has the highest likelihood; and wherein the weighing is performed in each update step of the plurality of update steps, characterized in that in update of an attenuation parameter μ j n+1 is calculated from the attenuation parameter μ j n by μ j n + 1 = μ j n + μ j n ∑ i l ij ∑ i l ij d i e − < l i , μ n > − Y i / σ Y i 2 ∑ i l ij / σ Y i 2 ∑ i l ij < l i , μ n > d i e − < l i , μ n > wherein d i is a number of photons emitted by the source of radiation; wherein l ij is a basis function of an i-th projection; wherein l i is a vector of basis functions l ij of the i-th projection; and wherein < / i , μ >= ∑ j l ij μ j is an inner product. reconstructing (S6) an image of the object of interest on the basis of the data set; wherein a statistical weighing is performed during reconstruction of the image, wherein the data set is a projection data set acquired by means of a source of electromagnetic radiation generating a beam and by means of a radiation detector detecting the beam, wherein the reconstruction of the image is performed on the basis of an iterative algorithm comprising a plurality of update steps until an end criterion has been fulfilled, and determining a number of detected photons Y i during acquisition of the data set; wherein the weighing is based on an intrinsic statistical error σ Y i of the number of detected photons Y i , wherein each update step comprises subtractions weighted with the intrinsic statistical error σ Y i , based on the number of detected photons Y i , during reconstruction of the image, wherein σ Y i , is the square root of Y i , wherein each update is a result of a respective cycle of the iterative algorithm, wherein the iterative algorithm is a maximum likelihood algorithm; wherein the reconstructed image has the highest likelihood; and wherein the weighing is performed in each update step of the plurality of update steps, characterized in that in update of an attenuation parameter μ j n+1 is calculated from the attenuation parameter μ j n by μ j n + 1 = μ j n + μ j n ∑ i l ij ∑ i l ij d i e − < l i , μ n > − Y i / σ Y i 2 ∑ i l ij / σ Y i 2 ∑ i l ij < l i , μ n > d i e − < l i , μ n > wherein d i is a number of photons emitted by the source of radiation; wherein l ij is a basis function of an i-th projection; wherein l i is a vector of basis functions l ij of the i-th projection; and wherein < / i , μ >= ∑ j l ij μ j is an inner product. wherein d i is a number of photons emitted by the source of radiation; wherein l ij is a basis function of an i-th projection; wherein l i is a vector of basis functions l ij of the i-th projection; and wherein < / i , μ >= ∑ j l ij μ j is an inner product. <EOS>