Ultrasound matrix imaging for 3D transcranial in vivo localization microscopy

Area of Science:

• Medical Imaging
• Biomedical Engineering
• Neuroscience

Background:

• Transcranial ultrasound imaging faces limitations due to skull-induced signal attenuation and aberrations.
• Ultrasound localization microscopy (ULM) achieves micrometer-scale brain vessel imaging using microbubbles and ultrafast techniques.
• Wavefront distortions in ULM reduce microbubble detection and localization accuracy.

Purpose of the Study:

• To address wavefront distortions limiting ultrasound localization microscopy (ULM) for transcranial brain imaging.
• To introduce and validate ultrasound matrix imaging as a solution for improved ULM performance.
• To demonstrate enhanced in vivo imaging of deep brain microvessels.

Main Methods:

• Utilized ultrasound matrix imaging, based on reflection matrix recording, to compensate for wave distortions.
• Performed in vivo experiments on anesthetized sheep to reconstruct deep brain microvessels.
• Applied ultrafast imaging with microbubble contrast agents for enhanced signal-to-noise ratio and super-resolution.

Main Results:

• Ultrasound matrix imaging effectively compensated for wave distortions in transcranial ultrasound.
• Significant enhancement in contrast and resolution of ULM was observed.
• Successful in vivo reconstruction of deep brain microvessels in sheep was achieved.

Conclusions:

• Ultrasound matrix imaging offers a viable solution to overcome fundamental limitations in transcranial ULM.
• The compensated ULM shows promise for nonionizing, deep brain microvascular imaging.
• This approach could advance the observation of human cerebral microvascular pathologies like stroke.