A method for determining the velocity of a fluid in a volume to be imaged of an examination object with the aid of an imaging method is described. Attenuation values are acquired based upon image data of the volume to be imaged, depending on location and time. A temporally and spatially delineated region is specified based upon the acquired attenuation data, in which the acquired attenuation data behaves approximately linearly. Subsequently, temporal and/or spatial gradients and/or a combination of a temporal and a spatial gradient are determined based upon the attenuation values associated with the temporally and spatially delineated region. Finally, the velocity of the fluid is calculated based upon the determined temporal and/or spatial gradients or from the combination of a temporal and a spatial gradient and from the temporal gradient. A fluid velocity determining device, non-transitory computer readable medium and a computed tomography system are also described.
