High-Speed Volumetric Dual-Mode Ultrasound and Photoacoustic Tomography With a Single-Element Detector.

Area of Science:

• Biomedical Imaging
• Acoustic Wave Technology
• Medical Physics

Background:

• Traditional 3D ultrasound (US) and photoacoustic (PA) tomography often require complex, costly transducer arrays.
• Ergodic relay (ER) approaches with single-element transducers offer potential for simplified, faster, and more cost-effective imaging.
• A need exists for integrated systems capable of dual-mode imaging with reduced hardware complexity.

Purpose of the Study:

• To develop and demonstrate a dual-mode system for simultaneous 3D photoacoustic (PA) and ultrasound (US) imaging using a single-element detector and an ergodic relay.
• To leverage the complementary contrast mechanisms of PA (optical absorption) and US (acoustic scattering) imaging.
• To achieve ultrafast, label-free, and non-invasive 4D imaging with simplified hardware.

Main Methods:

• Implementation of a dual-mode system integrating an ergodic relay with a single-element transducer for 3D PA and US imaging.
• Utilizing single ultrasonic or optical excitation pulses to generate 1D signals for 3D image reconstruction in both PA and US modes.
• Demonstration of the system's capability through in vivo imaging of human hand vasculature and skin structures.

Main Results:

• Successful single-shot, 3D reconstruction of images in both photoacoustic and ultrasound modes from 1D signals.
• Acquisition of complementary contrast information: optical absorption from PA and acoustic scattering from US.
• Demonstration of non-invasive, label-free, and ultrafast in vivo imaging of human hand structures, including blood vessels and skin.
• Feasibility of 4D imaging achieved with significantly simplified hardware.

Conclusions:

• The developed dual-mode system effectively combines 3D PA and US imaging using an ergodic relay and a single transducer.
• This approach offers a low-cost, simplified, and ultrafast solution for advanced biomedical imaging, including 4D applications.
• The system provides complementary contrast mechanisms for comprehensive tissue characterization in vivo.