In an electron microscope, it is most important to optimize , for a given irradiation dose, the information extracted from the specimen . The STEM configuration is quite suited for such developments because it can easily be equipped with a set of detectors for recording simultaneous signals . When associated with novel processing modes, this multisignal imaging approach affords interesting developments in many fields of applications, as illustrated here on a simple example . A VG STEM with a magnetic spectrometer for energy loss studies, has been fitted with four different detection channels, as shown in Fig 1 . These are : the beam current measurement (Icur), the annular dark field image (Iadf), the unscattered (Iun ), and total inelastic signal (Iin ). These latter contributions are discriminated on two separate detectors after magnification of the EELS spectrum with a dedicated double gap electron lens, see (1) for complete description of the design. Before introducing these different data in the appropriate analytical expressions which involve sums, differences or ratios, it is necessary to evaluate their relative weights, i.e the ratios of their detection efficiencies. Following the general principle described in (2), a reconstructed image of the primary beam current is obtained as a suitable linear combination of the three other signals . New images can then be generated for : a) the enhancement of the signal to noise ratio in low dose condition; b) the separation of the elastic and inelastic contributions; c) the improvement of the Z contrast; d) the development of mass thickness measurements. These latter two aspects are illustrated in the present abstract.