A medical X-ray device arrangement for producing three-dimensional information of an object in a medical X-ray imaging, the medical X-ray device arrangement comprising an X-ray source for X-radiating the object from at least two different directions and a detector for detecting the X-radiation to form projection data of the object. The medical X-ray device arrangement comprises means for modelling X-ray attenuation coefficient of said object using a multiresolution representation, eliminating part of the coefficients in said multiresolution representation to form reduced multiresolution representation, and utilizing said projection data in a regularized reconstruction method based on minimizing the penalty F(f)=.parallel.Af-m.parallel.2/2+.alpha..parallel.f.parallel..sub.B+.beta- .g(f) over the coefficients in the said reduced multiresolution representation to produce three-dimensional information of the object.