Researchers have developed a compact handheld imaging probe that could expand the clinical and research use of photoacoustic microscopy, a technique known for producing high-resolution three-dimensional images of living tissue.
Photoacoustic microscopy combines light and ultrasound to visualise anatomical structures, blood vessels and molecular activity. Although it has been widely used in laboratory settings, translating the technology into a practical handheld device has proved difficult because of challenges in balancing size, speed, image resolution and signal quality.
Compact Design with High Resolution
In the new study, scientists describe a handheld probe that integrates a fibre scanner with a high frequency transparent ultrasound transducer. The device, referred to as hPAM TUT, has a rigid body measuring 90 mm in length and just 17 mm in diameter, making it suitable for handheld use.
Despite its small size, the system delivers high performance imaging. It achieves a lateral resolution of 7 micrometres and an axial resolution of 47 micrometres, with a field of view measuring 2.6 mm in diameter. A full volumetric image can be captured in 1.5 seconds, allowing relatively rapid imaging while maintaining a strong signal to noise ratio.
The combination of speed and spatial resolution addresses one of the main limitations of previous handheld photoacoustic microscopy systems, which often required trade-offs between image quality and practicality.
Probe Demonstrated in Living Animals
The researchers tested the probe in a series of animal studies. In living rats, the device was used to visualise several abdominal organs in three dimensions. In mice, it enabled observation of vascular changes triggered by epinephrine, demonstrating its ability to capture functional changes in blood vessels.
The system was also used to image lymphatic vessels after injection of Evans blue dye, allowing the researchers to assess both lymphatic anatomy and function. In addition, the probe successfully delineated vascular networks in early-stage metastatic tumours in mice, highlighting its potential value in cancer research.
Potential Clinical Applications
The authors suggest that the handheld probe could support a range of future applications. These include dermatology, oncology and intraoperative imaging, where real-time, high-resolution visualisation of tissue and blood vessels could aid diagnosis and surgical decision making.
While further development and clinical testing will be needed, the study demonstrates that compact handheld photoacoustic microscopy devices can achieve fast imaging with high resolution, bringing the technology closer to routine clinical and translational research use.
Reference
Ha M et al. A handheld photoacoustic microscopic probe integrating a transparent ultrasound transducer and a fiber scanner. Nature Communications. 2025; https://doi.org/10.1038/s41467-025-68148-8.
