P5B-2 Imaging Microbubble Destruction/Replenishment with Nakagami Distribution

Contrast-assisted techniques that quantitatively estimate time-intensity curves (TICs) within the perfusion area have been applied in many disease models. In this study, we monitored the microbubble replenishment by a proposed new approach called the time-Nakagami-parameter curve (TNC) obtained from Nakagami-parameter images for quantifying the microvascular flow velocity. The feasibility of using the TNC to estimate the microvascular flow was evaluated in phantom experiments of the TIC and TNC. The rates of increase of the TIC and TNC were expressed by the rate constants beta₁ and beta_N of a monoexponential model, respectively. The results showed that beta_N quantifies the flow velocity similarly to the conventional beta₁. In particular, the TNC-based technique conditionally tolerates the presence of nonperfused areas (e.g., surrounding tissues or vessel walls) in the region of interest without requiring application of an additional wall filter to cancel the influences of clutter echoes on the flow estimation.