Patent ID: 7215730

Claim:
A method for producing three-dimensional information of an object in medical X-ray imaging in which method the object is X-radiated from at least two different directions and the said X-radiation is detected to form projection data of the object, characterized in that, X-ray attenuation coefficients of said object are modelled using a multiresolution representation, part of the coefficients in said multiresolution representation is eliminated to form reduced multiresolution representation, and said projection data is utilized in a regularized reconstruction method based on minimizing the penalty F ( f )=∥ Af−m∥ 2/2+α∥ f∥ B +βg ( f ) over the coefficients in the said reduced multiresolution representation, f representing the object image vector, which comprises values of the X-ray attenuation coefficient inside the object, m representing projection data, A representing the X-radiation attenuation model matrix, α representing a positive number, β representing a non-negative number, g representing a function returning zero for positive arguments and returning positive values for negative arguments and ∥f∥ B representing magnitude of f expressed in terms of coefficients of f in the multiresolution representation of f, such that said three-dimensional medical X-ray imaging information of the object is reconstructed from said regularized reconstruction method.