<latex>In conventional echography, ultrasonic arrays employ beamforming (applying appropriate time delays in emission and reception) to form images. It is commonly assumed that the medium under consideration is homogeneous, with constant acoustic velocity. However, in heterogeneous media, variations in acoustic impedance cause propagating waves to dephase; such aberration effects lead to distortion that decrease the image quality. Furthermore, the speed of sound may vary with position, resulting in multiple isoplanetic areas ? different aberration effects in different areas of the image. Techniques such as adaptive focussing and matched filter methods have been developed to correct for aberration, but most require either iterative focussing, optimization based on image quality, or the presence of dominant scatterers as guidestars, and none can simultaneously correct for multiple isoplanetic areas. ≠wline In this talk, we present a powerful method of aberration correction based on the distortion matrix concept. This operator compare each wavefront generated from any focal spot with an expected one obtained in the ideal condition of homogeneous medium. As a result, it connect any point inside the medium with the distortion that a wavefront, emitted from that point, experiences due to heterogeneities. Even in speckle, a time-reversal analysis of this operator enables the estimation of the transmission matrix that links each sensor and image voxel. Phase aberrations can then be unscrambled for any point, thereby providing a full-field image of the medium with diffraction-limited resolution. </latex>