Number of Time Slots (0054,0071) is the number of frames into which each gating event is divided in a gated acquisition. For example, in a cardiac gated acquisition, data from a number of heartbeats are then combined by summing together the first frames from all beats into a summed first frame, all the second frames into a summed second frame, and so on. The result has the same number of frames as the Number of Time Slots in each beat.
Time Slot Vector (0054,0070) is an indexing vector. The value of the nth element of this vector is the time slot number of the nth frame in this image, and shall have a value from 1 to Number of Time Slots (0054,0071).