Visualization of Renal Glomeruli in Human Native Kidneys With Sensing Ultrasound Localization Microscopy

Area of Science:

• Nephrology
• Medical Imaging
• Ultrasound Technology

Background:

• Kidney diseases severely affect quality of life and life expectancy.
• Glomeruli are vital for kidney function but are too small for current imaging.
• Sensing ultrasound localization microscopy (sULM) shows promise for in vivo glomeruli visualization.

Purpose of the Study:

• To assess sULM's ability to visualize glomeruli in native human kidneys.
• To compare sULM parameters in native kidneys versus kidney grafts.
• To evaluate glomeruli detection despite kidney depth and apnea limitations.

Main Methods:

• sULM imaging was performed on 15 patients with native kidneys and 5 with kidney allografts.
• Glomeruli counts were determined using normalized distance metrics on sULM density maps.
• Differences in acquisition time, kidney depth, and frame rate were analyzed.

Main Results:

• Glomerular visualization was successful in 12 of 15 native kidney patients.
• sULM detected an average of 16 glomeruli/cm² in native kidneys and 33 glomeruli/cm² in kidney grafts.
• Visualization failures were linked to breath-holding difficulties or deep kidney location.

Conclusions:

• sULM is capable of in vivo glomeruli visualization in native human kidneys.
• This technique offers potential applications in biomarker development and biopsy assistance/avoidance.
• sULM provides a framework for enhanced detection of microstructural pathology and disease monitoring.