A Validation of Spatially Compounded Volumetric Ultrasound Localization Microscopy for Glomerular Imaging With Light...

Area of Science:

• Nephrology
• Biomedical Imaging
• Medical Diagnostics

Background:

• Current kidney health assessments rely on indirect markers or invasive biopsies.
• Existing imaging methods lack the resolution for in vivo glomerular visualization across the entire kidney.

Purpose of the Study:

• To perform whole-kidney ultrasound localization microscopy (ULM) for quantifying glomerular microvascular structure and function.
• To evaluate ULM's performance against light-sheet microscopy (LSM) as a gold standard.

Main Methods:

• High-frame-rate ULM was used for whole-kidney imaging in a rat model.
• Microbubble contrast agents and advanced processing reconstructed renal vasculature.
• Spatially registered volumetric data provided a comprehensive kidney dataset.
• Light-sheet microscopy (LSM) was used for gold-standard comparison.

Main Results:

• ULM achieved sub-diffraction resolution, visualizing cortical vasculature and individual glomeruli.
• Glomerular density measurements by ULM (21.3 ± 8.0/mm³) closely matched LSM (28.6 ± 7.5/mm³) and histological data.
• ULM successfully visualized microvascular flow velocities throughout the kidney.

Conclusions:

• ULM is validated as a proof-of-concept for quantitative in vivo glomerular assessment.
• ULM shows potential for whole-kidney, glomerulus-level assessment of renal microstructure and hemodynamics.
• This technique holds promise for future translational applications in kidney disease diagnosis and monitoring.