A subject is imaged at a preselected phase point (34) which occurs in one or more successive cardiac cycles as the subject moves in an examination region (16). An illumination window (94) illuminates each reconstructed voxel (A, B, C) of the subject in phase point windows (92) adjacent surroundingly the preselected phase point (34). A temporal window (90) is determined which includes an integer number N of successive cardiac cycles, in which the phase point windows (92) are entirely included in the illumination window (94). The illumination window (94) is truncated in accordance with the determined temporal window (90). First and second regions (72, 74) are determined along an axial direction (Z), the first and second regions (72, 74) alternating with one another. A temporal weighting profile processor (64) generates a projection dependent temporal weighting profile (66). A temporal window processor (102) applies the normalized backprojection weights for each voxel which lies in an associated first region. A varying weight processor (110) continuously smoothly weights readings for each voxel lying in an associated second region (74). A backprojection processor (120) three-dimensionally backprojects the weighted readings into a volumetric image representation.