A newly developed imaging methodology blends ultrasound and photoacoustics to seize each tissue construction and blood-vessel perform in 3D.
By mixing two highly effective imaging strategies, researchers from Caltech and USC have developed a brand new technique to see contained in the human physique with unprecedented pace and element. The method produces three-dimensional, full-color photographs that present not solely the form of soppy tissues but in addition how blood vessels are functioning in actual time. In early demonstrations, the researchers efficiently imaged a number of completely different components of the human physique, highlighting the flexibility of the strategy.
This mixed imaging methodology might considerably enhance how medical doctors detect and examine illness. Potential functions embrace extra exact breast tumor imaging, new methods to trace nerve injury brought on by diabetes, and superior instruments for observing mind construction alongside blood circulation. The work suggests a path towards medical scans which are each extra informative and simpler to repeat over time.
The researchers describe the brand new know-how in a paper printed in Nature Biomedical Engineering.
Medical imaging usually requires tradeoffs between pace, price, and the kind of data that may be captured. Ultrasound, probably the most extensively used strategies, is quick, cheap, and effectively suited to visualizing the construction of tissues. Nonetheless, it usually supplies solely two-dimensional views and can’t simply seize a large space or reveal detailed details about blood chemistry or circulation.
Photoacoustic imaging addresses a few of these gaps however introduces others. On this strategy, laser gentle is distributed into the physique, the place it’s absorbed by molecules in blood vessels. That absorption generates sound waves that may be detected and translated into photographs. As a result of completely different molecules take in gentle in distinct methods, photoacoustic imaging can show blood vessels in optical shade—permitting for visualization of how blood strikes by means of arteries and veins. By itself, nevertheless, the method doesn’t present sufficient structural element to totally map surrounding tissues.
Different superior imaging instruments, corresponding to computed tomography (CT) scanning and magnetic resonance imaging (MRI), can ship detailed views of anatomy, however they arrive with notable downsides. These strategies will be pricey, could require distinction brokers, typically contain publicity to ionizing radiation, or take too lengthy to be sensible for frequent monitoring or bedside use.
Combining Ultrasound and Photoacoustics
To beat these limitations, the researchers developed RUS-PAT (rotational ultrasound tomography, RUST, mixed with photoacoustic tomography, PAT). PAT was first developed greater than twenty years in the past by Lihong Wang, the Bren Professor of Medical Engineering and Electrical Engineering and the Andrew and Peggy Cherng Medical Engineering Management Chair at Caltech.
In PAT, molecules that take in gentle reply to quick laser pulses by vibrating, which generates acoustic indicators. These indicators can then be detected and processed to type detailed, high-resolution photographs.
Wang, who can be the manager officer for medical engineering at Caltech, says his group’s goal with the present work was to mix the advantages of PAT with ultrasound. “But it surely’s not like one plus one,” he says. “We would have liked to search out an optimum means of mixing the 2 applied sciences.”
Ultrasound usually makes use of many transducers to each generate and obtain ultrasound waves, and mixing this course of straight with PAT can be too complicated and costly for widespread use. PAT, in the meantime, solely requires the detection of ultrasound, and that gave Wang an concept. “I assumed, ‘Wait, can we simply mimic gentle excitation of ultrasound waves in photoacoustic tomography, however do it ultrasonically?'” PAT permits laser gentle to diffuse inside the tissue, finally triggering the manufacturing of measurable ultrasound waves. Equally, Wang figured, they might use a single wide-field ultrasound transducer to broadcast an ultrasonic wave broadly into the tissue.
They may then use the identical detectors to measure the ensuing waves for each modalities. Within the new system, a small variety of arc-shaped detectors are rotated round a central level, permitting it to behave like a full hemispheric detector however at a fraction of the complexity and price.
Demonstrated Medical Potential
“The novel mixture of acoustic and photoacoustic strategies addresses lots of the key limitations of extensively used medical-imaging strategies in present scientific apply, and, importantly, the feasibility for human utility has been demonstrated right here in a number of contexts,” says Dr. Charles Y. Liu, an creator of the paper who’s a visiting affiliate in biology and organic engineering at Caltech. Liu can be a professor on the Keck Faculty of Medication of USC, director of USC’s Neurorestoration Middle, and chair of neurosurgery on the Rancho Los Amigos Nationwide Rehabilitation Middle.
The RUS-PAT method might probably be utilized in any area of the physique to which gentle will be delivered, and for functions the place clinicians or researchers would profit from the synergistic imaging of each the morphology and color-related perform. For instance, RUS-PAT might enhance breast-tumor imaging, giving physicians the power to know a tumor’s precise location and environment in addition to its pathology and physiology. It might additionally assist medical doctors monitor the nerve injury brought on by diabetic neuropathy by offering an all-in-one technique to monitor oxygen provide together with morphology. Wang says the method is also helpful in mind imaging, permitting scientists to look at the structural particulars of the mind whereas additionally with the ability to observe hemodynamics.
At the moment, the system can scan to a depth of about 4 centimeters. Gentle will also be delivered endoscopically, probably making deeper tissues accessible to the brand new know-how. A RUS-PAT scan will be carried out in lower than one minute.
The present setup entails a scanning system with ultrasound transducers and laser housed beneath a mattress. It has been demonstrated on human volunteers and sufferers and is within the early phases of translational growth.
Reference: “Rotational ultrasound and photoacoustic tomography of the human physique” by Yang Zhang, Shuai Na, Jonathan J. Russin, Karteekeya Sastry, Li Lin, Junfu Zheng, Yilin Luo, Xin Tong, Yujin An, Peng Hu, Konstantin Maslov, Tze-Woei Tan, Charles Y. Liu and Lihong V. Wang, 16 January 2026, Nature Biomedical Engineering.
DOI: 10.1038/s41551-025-01603-5
The work was supported by funding from the Nationwide Institutes of Well being.
