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

Ultrasound localization microscopy (ULM) enables imaging of cerebral vasculature at a microscopic scale with deep penetration. However, conventional 2-D ULM suffers from elevation projection and cannot capture the out-of-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 $15.36\times 15.36$ mm2, which is suitable for volumetric imaging of small animals and superficial organs. The 3-D rendering of super-resolved vascular density and velocity maps was performed to visualize the cerebral vasculature at an improved spatial resolution of $24.7~\mu $ m. 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.