Abstract: In the isocount scintiscanning, the detector probe is scanned over the object plane such that it is stopped at each observation point during the time T necessary for the input pulses to reach a preset value N. The count rate R = N/T is then calculated electronically and the two-dimensional array of said count rate R.sub.i,j, output of said isocount scanner, is read in the memory of the display system, which is the subject to the present patent. These data are read out from said memory in synchronism with the television horizontal sweep signal; each value of count rate R.sub.i,j is compared to a reference slice level a.sub.k and if R.sub.i,j .gtoreq.a.sub.k, black is assigned to the corresponding picture element on the screen; if R.sub.i,j <a.sub.k, white is assigned to the corresponding element on the screen. If said slice level a.sub.