An Unbiased Tissue Attenuation Coefficient Estimator Using Microbubble Echoes with Harmonic Ratio Compensation

摘要: For the tissue attenuation coefficient (TAC) estimator proposed in our previous paper [5], to have unbiased estimate of TAC separation between two vessels, it needs bubbles these vessels identical statistical properties, which can be achieved only when same diameter and blood pressure. To release this limitation, a compensation technique is suppress bias. In paper, follow Greenleaf's work, we introduce parameter named harmonic ratio (HR), second-harmonic signals, for bias suppression. This method use dual-frequency excitation produce harmonics. After applying HR TAC, shown that effect bubble number compensated. experimental make with different concentrations such properties echoes are cause severe on estimates, then estimates using kept unbiased.