All-Optical Rotational Ultrasound Imaging

Area of Science:

• Biomedical Engineering
• Optical Physics
• Medical Imaging

Background:

• Minimally invasive procedures require advanced imaging for guidance.
• Existing ultrasound technologies have limitations in miniaturization and resolution.

Purpose of the Study:

• To present an all-optical rotational B-mode pulse-echo ultrasound imaging system.
• To demonstrate its capability for high-resolution, real-time imaging in clinical settings.

Main Methods:

• Developed an all-optical transducer using a carbon nanotube composite coating on an optical fiber for ultrasound generation.
• Utilized a Fabry-Pérot cavity interrogated by a laser as an omnidirectional ultrasound receiver.
• Integrated these components into a miniaturized probe (1.25 mm diameter) for rotational imaging.

Main Results:

• Achieved an ultrasound beam with a 31.3 MHz bandwidth and 1.87 MPa peak-to-peak pressure.
• The receiver demonstrated a noise equivalent pressure below 100 Pa over a 20 MHz bandwidth.
• Provided imaging with axial resolution better than 50 µm at 5 frames per second.

Conclusions:

• The all-optical probe is a viable technology for clinical rotational ultrasound imaging.
• Demonstrated successful intraluminal imaging in swine carotid arteries.
• Highlights potential for enhanced guidance in vascular procedures.