1. A gamma radiation detection system of a gamma camera type or Compton camera type, comprising: a source of gamma rays; at least one plate P1 of a fast scintillator having a rise time to the light peak of less than 1 ns with a scattering entry surface and a polished exit surface, having a thickness greater than or equal to 10 mm, equipped with a segmented photodetector and dedicated reading microelectronics, wherein each segment of said photodetector is configured to locate a first trigger T1, corresponding to the time of arrival of the first UV ray emitted by the scintillation on said at least one plate P1, wherein the photodetector is configured to measure spatial and temporal distribution of the first adjacent photons emitted by an event on the detectors during a period of more than 100 ps and less than or equal to the rise time to the light peak of the scintillator thereby to spatially localize said event of coordinates (X1, Y1), wherein the photodetector is further configured to exploit the difference between spatial and temporal distribution of non-scattered photons and scattered photons to reconstruct the spatial and temporal coordinates (X1, Y1, Z1, T1) of said event, and wherein the first detected photons are the non scattered photons distributed within a disk whose radius depends on interaction depth (Z1) and wherein its centre represents a position (X1, Y1) of the event.