Real-time volumetric contrast-enhanced ultrasound and microbubble destruction-replenishment imaging: Preliminary in vitro and in vivo results

Noninvasive assessment of renal perfusion would help improve treatment and outcome for patients with acute kidney injury. Although there are current methods with the capability of imaging and quantifying renal vascularity perfusion parameters, the nephrotoxic nature of their contrast agents prevents their use on compromised kidneys. Ultrasound (US) contrast agents are both non-toxic and capable of enhancing visualization of vasculature by up to 25 dB. Described in this study are preliminary results for quantifying perfusion parameters in a flow phantom and rat kidney model with volumetric contrast-enhanced US (VCEUS) imaging. Results showed significant correlations between time-to-peak intensity and concentration flow rate in a phantom model (P < 0.05). Renal perfusion experiments in healthy rats validate VCEUS as a valuable tool for obtaining consistent time-intensity curves and parametric perfusion information. Further study is expected to reveal the advantageous nature of VCEUS for compromised and ischemic kidneys compared to alternative imaging modalities.