At least one example embodiment relates to a method and/or a device for automatically differentiating types of kidney stones using computed tomography. The method provides two image data records of two computed tomography pictures of an object area including the kidney stones that have been recorded in the context of a different spectral distribution of the X-radiation. For each voxel of a slice of the object area that has X-ray attenuation values typical of kidney stones there is calculated from the two image data records a ratio r that is yielded from X-ray attenuation values of the voxel and prescribed X-ray attenuation values of pure urine in the context of the different spectral distributions of the X-radiation. The respective voxel is assigned to one of at least two types of kidney stones as a function of the variable r.