Abstract: An assembly for televised radioscopy is described which comprises a source of X-rays, a device for generating a visual signal corresponding to the image of the body organ in motion being examined and a monitor provided with a screen. The assembly comprises a detecting device which has an input to which the visual signal is supplied, at least one output which is intended to be connected to the input of said monitor, a first processing electronic transducer device capable of generating and overlapping a registering signal which is overlapped with the visual signal, the registering signal is capable of causing at least one tracing PR on the televised picture of the monitor, the tracing corresponding to at least one point of the contour of the image of the body organ in motion, the tracing PR having a luminosity different from the luminosity of the surrounding portion.