Researchers at the California Institute of Technology and the University of Southern California have described a hybrid imaging approach—rotational ultrasound and photoacoustic tomography (RUS-PAT)—that produces quasi-simultaneous 3D structural ultrasound and 3D blood-vessel images. The system was demonstrated on human body regions including the head, breast, hand and foot, according to a study published in Nature Biomedical Engineering.
Researchers from the California Institute of Technology (Caltech) and the University of Southern California (USC) have introduced a hybrid imaging system called rotational ultrasound and photoacoustic tomography (RUS-PAT), which integrates rotational ultrasound tomography (RUST) with photoacoustic tomography (PAT) to capture complementary information in three dimensions. The method is designed to combine ultrasound’s ability to depict soft-tissue structure with photoacoustic imaging’s ability to visualize blood vessels. (nature.com)
The work was led by Lihong V. Wang, a Caltech professor and chairholder, who has been credited by Caltech’s release with developing photoacoustic tomography more than two decades ago. In PAT, brief laser pulses cause light-absorbing molecules in tissue to generate acoustic signals that can be reconstructed into images. Wang said merging the two modalities required careful optimization: “But it’s not like one plus one… We needed to find an optimal way of combining the two technologies.” (sciencedaily.com)
According to the peer-reviewed paper, the system’s rotational ultrasound tomography component achieves panoramic 3D detection using a single-element ultrasonic transducer for ultrasound transmission and rotating arc-shaped arrays for detection; switching from an acoustic source to a light source converts the system into photoacoustic mode to image vasculature in the same region. In demonstrations reported in the journal article, the team imaged the human head, breast, hand and foot with a 10-centimeter-diameter field of view, submillimetre isotropic resolution, and about 10 seconds of imaging time for each modality. (nature.com)
The institutional release and syndicated summaries report that a full RUS-PAT scan can be performed in less than one minute, and that the current configuration reaches a depth of about 4 centimeters; they add that delivering light endoscopically could extend the approach to deeper tissues. These statements were not all detailed in the article abstract, but were reported in the Caltech-linked write-up distributed by ScienceDaily. (sciencedaily.com)
The study is titled “Rotational ultrasound and photoacoustic tomography of the human body.” The journal lists Yang Zhang, Shuai Na, and Jonathan J. Russin as equal-contribution authors, and names Charles Y. Liu and Lihong V. Wang as corresponding authors; the ScienceDaily summary also describes Zhang, Na and Russin as co-lead authors. (nature.com)
Potential clinical uses discussed around the work include improved visualization of tissue morphology together with angiographic information for diagnosing and monitoring disease, though the researchers emphasize the technology is still at an early translational stage. The paper’s acknowledgements list funding from the U.S. National Institutes of Health, including grants R01 CA282505, U01 EB029823 and R35 CA220436. (nature.com)
