The invention relates to a computer tomography method in which a
periodically moving object, in particular an organ of the body, is
irradiated by a cone-shaped beam cluster (4) along a trajectory which
runs on a cylindrical surface. The radiation transmitted through the
object is measured by means of a detector unit (16), and at the same time
the periodic movement of the object is recorded. In order to reconstruct
the absorption distribution of the object, the measured values or the
corresponding beams are rebinned to form a number of parallel
projections, where for each of these projections a measured value is
determined whose beam irradiates the object. The point in time at which
this measured value was acquired is allocated to the respective
projection. For the reconstruction, which may for example be carried out
using a filtered back-projection, only projections whose allocated points
in time lie within a predefined, specific time range (H1) within a period
of the object movement are used.