Elisa E. KONOFAGOU^{1, 2}, Tomy VARGHESE¹, Jonathan OPHIR^{1, 2, 3}

¹Ultrasonics Laboratory, Dept. of Radiology, University of Texas Medical School, ²Bioengineering Research Center, University of Houston, ³Department of Electrical Engineering, University of Houston

キーワード : Baseband, Dynamic range, Elastography, RF, Strain

Expanding the dynamic range in elastography is important since the stiffness dynamic range encountered in the pathological breast is on the order of 40-60 dB, while a single compression elastogram is limited to a dynamic range of only 15-20 dB. It has recently been shown that using variable applied compressions significantly improves the dynamic range of hard regions. However, some softer regions in the elastogram may remain noisy. A technique that selects high signal-to-noise ratio (SNR_e) strain data obtained by a careful combination of processing both baseband and bandpass signals was shown to estimate soft tissue strains more accurately. In this paper we combine the two techniques along with averaging of the available strain data to obtain a composite elastogram that displays the entire dynamic range of strains in tissue. This way we can achieve both a signal-to-noise ratio and a dynamic range improvement, two main measures of image quality in elastography at a given resolution. Results of this method are shown on 2-D simulations.