AUTOMATIC ATTENUATION COMPENSATION FOR ULTRASONIC-IMAGING

A new method has been developed for the automatic correction for atten uation in ultrasonic pulse-echo imaging, By assuming that a specified relationship holds between local attenuation and local backscatter thr oughout each pulse-echo signal, a gain factor mag be calculated that m ore appropriately compensates for attenuation at every depth, The rati onale depends on the observation that, broadly speaking, materials tha t backscatter strongly also attenuate strongly, The new method has bee n evaluated by postprocessing clinical B-scans following video frame c apture, 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 f etal lung was imaged uniformly irrespective of the presence of rib or spine, and prostatic tissue was imaged uniformly through a partial bla dder window. Spatial resolution and speckle patterns are retained, The method is suitable for real-time application. (C) 1997 World Federati on for Ultrasound in Medicine & Biology.