Authors’ summetry: High resolution double crystal diffractometers are used to determine the internal ferromagnetic structure of crystals, e.g. FeSi samples. The measured data correspond to the Radon transform of the 2D scattering distribution of the crystal. We develop and compare tomographic methods such as the algebraic reconstruction technique and the filtered backprojection algorithm for this application. This method allows us to image scattering patterns in the very low \(Q\)-range of \(Q \sim 10^{-5} {\overset\circ A}^{-1}\) which is about two orders of magnitude lower than the conventional small angle techniques.