A method for acquiring a 3D image dataset is proposed. A 3D X-ray image dataset of an image object is acquired during scanning of a partial circle by X-ray radiation source and X-ray radiation detector. A first and a second 3D image datasets are calculated from the acquired image dataset. Redundancies are eliminated by averaging the first and second 3D image datasets. A filtering that is antisymmetric in respect of a center of symmetry is performed in respect of the 2D image datasets in calculating the second 3D image dataset. Said filtering has a row-by-row Hilbert transform. Suitable weights can be specified based on an axis defined in space.