Nonlinear sound-sheet microscopy: Imaging opaque organs at the capillary and cellular scale

Area of Science:

• Biomedical imaging
• Acoustic microscopy
• Molecular imaging

Background:

• Light-sheet fluorescence microscopy is limited by light scattering and photobleaching in thick tissues.
• Studying dynamic cellular processes in vivo often requires imaging beyond the penetration depth of light.

Purpose of the Study:

• To develop a novel imaging method for fast and volumetric visualization of biological functions in centimeter-scale volumes.
• To overcome the limitations of optical microscopy in scattering and opaque biological tissues.

Main Methods:

• Application of nondiffractive ultrasound beams with a cross-amplitude modulation sequence.
• Utilizing nonlinear acoustic reporters, including genetically encoded gas vesicles and intravascular microbubbles.
• Development of nonlinear sound-sheet microscopy for accelerated imaging.

Main Results:

• Achieved volumetric imaging of tumor gene expression at the cubic centimeter scale.
• Enabled localization microscopy of cerebral capillary networks using microbubble contrast agents.
• Demonstrated ~64x acceleration in imaging speed, ~35x increase in imaged volume, and ~4x resolution improvement.

Conclusions:

• Nonlinear sound-sheet microscopy offers a significant advancement for deep-tissue biological imaging.
• The technique enables high-speed, volumetric functional imaging at unprecedented scales.
• This method expands the possibilities for studying complex biological processes in vivo.