High-Frame-Rate Volumetric Porcine Renal Vasculature Imaging

Objective: The aim of this study was to assess the feasibility and imaging options of contrast-enhanced volumetric ultrasound kidney vasculature imaging in a porcine model using a prototype sparse spiral array.Methods: Transcutaneous freehand in vivo imaging of two healthy porcine kidneys was performed according to three protocols with different microbubble concentrations and transmission sequences. Combining high-frame-rate transmission sequences with our previously described spatial coherence beamformer, we determined the abil-ity to produce detailed volumetric images of the vasculature. We also determined power, color and spectral Dopp-ler, as well as super-resolved microvasculature in a volume. The results were compared against a clinical 2-D ultrasound machine.Results: Three-dimensional visualization of the kidney vasculature structure and blood flow was possible with our method. Good structural agreement was found between the visualized vasculature structure and the 2-D reference. Microvasculature patterns in the kidney cortex were visible with super-resolution processing. Blood flow velocity estimations were within a physiological range and pattern, also in agreement with the 2-D reference results.Conclusion: Volumetric imaging of the kidney vasculature was possible using a prototype sparse spiral array. Reli-able structural and temporal information could be extracted from these imaging results.