Automatic attenuation compensation for ultrasonic imaging.

A new method has been developed for the automatic correction for attenuation in ultrasonic pulse-echo imaging. By assuming that a specified relationship holds between local attenuation and local backscatter throughout each pulse-echo signal, a gain factor may be calculated that more appropriately compensates for attenuation at every depth. The rationale depends on the observation that, broadly speaking, materials that backscatter strongly also attenuate strongly. The new method has been evaluated by postprocessing clinical B-scans following video frame capture. The images formed demonstrated the success of the algorithm in imaging homogeneous tissues at a constant grey level, irrespective of variations in the attenuation of overlying tissue. For example, the fetal lung was imaged uniformly irrespective of the presence of rib or spine, and prostatic tissue was imaged uniformly through a partial bladder window. Spatial resolution and speckle patterns are retained. The method is suitable for real-time application.