Single Crystal Row-Column Array based Rat Brain 3-D Ultrasound Localization Microscopy.

Ultrasound localization microscopy (ULM) enables imaging of cerebral vasculature at microscopic scale with deep penetration. However, conventional two-dimensional (2D) ULM suffers from the elevation projection and cannot capture the outof- plane vessels. Recently developed volumetric ULM overcomes the limitations by providing isotropic resolution and enabling comprehensive visualization of the microvascular architecture in three dimensions. In this study, we developed a single crystal 128 + 128 row-column addressed (RCA) probe centered at 13 MHz, with a bandwidth of 80% and a large aperture of 15.36 × 15.36 mm², which is suitable for volumetric imaging of small animals and superficial organs. Three-dimensional rendering of superresolved vascular density and velocity maps was performed to visualize the cerebral vasculature at an improved spatial resolution of 24.7 μm. The developed methodology demonstrated the performance of single-crystal RCA based in vivo volumetric imaging of micro-cerebrovascular, highlighting its high potential for studying neurodegenerative diseases, intracranial aneurysms, and stroke.