We present a technique that records transient effects in the fluorescence lifetime of a sample with spatial resolution along a one-dimensional scan. The technique is based on building up a photon distribution over the distance along the scan, the arrival times of the photons after the excitation pulses, and the experiment time after a stimulation of the sample. The maximum resolution at which lifetime changes can be recorded is given by the line scan time. With repetitive stimulation and triggered accumulation, transient lifetime effects can be resolved at a resolution of about one millisecond. The technique can be used in all bh FLIM systems based on the bh SPC-830 or SPC-150 TCSPC modules.