2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/85044In this paper a general and unified treatment of the DQE is exposed, both in the space-domain and in the frequency-domain. The meaning of the DQE as quantum efficiency appears to be of paramount importance for a correct interpretation of the physical parameters involved in its formulation and measurement. The treatment in the frequency-domain turns out to be a direct extension of that in the space-domain. An operational procedure is introduced to consider the effect of the filtering of the detector in the space-domain.10 pages, 2 figuresInstrumentation and Detectorstext