Full noncontact laser ultrasound: first human data

Area of Science:

• Biomedical Optics
• Acoustics
• Medical Imaging

Background:

• Current medical ultrasound (US) requires coupling gels and operator skill, limiting repeatability and image quality.
• Existing light-based ultrasound, such as photoacoustics (PA), often still requires physical contact or close proximity of detectors.
• Noncontact imaging modalities are desirable for improved patient comfort, reduced infection risk, and enhanced image acquisition.

Purpose of the Study:

• To present a full noncontact laser ultrasound (LUS) imaging system.
• To demonstrate the capabilities of LUS for deep tissue imaging and volumetric data acquisition.
• To validate LUS performance from phantoms to in vivo human imaging.

Main Methods:

• Developed a novel LUS system that restricts optical-to-acoustic energy transduction to the tissue surface.
• Utilized interferometry for noncontact acoustic detection.
• Performed imaging on tissue-mimicking phantoms, excised animal tissue, and human subjects at safe optical exposure levels.

Main Results:

• Achieved noncontact imaging of targets at depths up to 5 cm with a meter-scale standoff.
• Demonstrated volumetric imaging capabilities with LUS.
• Acquired the first in vivo human LUS images, validated by conventional ultrasound.

Conclusions:

• Full noncontact LUS imaging is feasible and offers significant advantages over conventional ultrasound.
• The presented LUS system demonstrates potential for clinical translation.
• This technology represents a significant advancement toward noncontact, operator-independent medical ultrasound imaging.