We first present an imaging technique based on the diffraction tomography approach . Experimental results on phantoms will be used to analyse this method at its various stages and illustrate its capabilities. The images is a map of the density of the sources induced in the object by the incident wave. This density is the product of the pressure field in the object by a simple function f (C, a) of the sound speed C and attenuation a in the object . We then present an iterative algorithm that isolate f (C, a) and allows the determination of C and a . This approach will be discussed through results obtained by numerical simulation .