Modern medicine relies on imaging to explore the inside of the body, but each technique has its constraints. While ultrasound is fast and inexpensive, it reveals little about the function of blood vessels. On the other hand, methods like MRI offer precise anatomical details, but at the cost of a lengthy and expensive examination. A team of researchers may have found a way to merge the advantages of these approaches by combining two technologies.
Named RUS-PAT, this new method was developed by scientists from Caltech and USC. It combines rotational ultrasound with photoacoustic tomography to produce three-dimensional, color images. These show both the shape of soft tissues and the activity of blood vessels in real time. Initial tests on human volunteers confirmed its ability to clearly illustrate various regions of the body.
The RUS-PAT hybrid combines fast rotational ultrasound with photoacoustic tomography for near-simultaneous 3D imaging of soft tissue structure and vasculature. The system has been used to image several human anatomical regions. Credit: Yang Zhang Conventional ultrasound uses sound waves to create images of internal structures, but it is often limited to two-dimensional views. Meanwhile, photoacoustic imaging emits laser light absorbed by molecules in the blood, generating detectable sound waves. This approach makes it possible to observe blood circulation with optical colors, but it provides little information about surrounding tissues. Each technique therefore has its own strengths and weaknesses.
To overcome these limitations, the researchers designed a system that simulates the light excitation of photoacoustic tomography with ultrasound. A small number of arc-shaped detectors rotate around a central point, mimicking the action of a hemispherical detector at a lower cost. This streamlined configuration simultaneously captures structural and functional data, thus avoiding the difficulties of traditional approaches that require many transducers.
The medical applications of RUS-PAT are numerous. For example, in breast imaging, it could help accurately locate tumors and examine their physiology. For diabetic neuropathy, it provides a way to monitor oxygen supply and nerve damage in a single examination. In the neurological field, it would allow observation of both brain architecture and blood flow dynamics, offering new possibilities for the study of brain diseases.
Currently, the system can scan up to about 1.6 inches (4 centimeters) deep in less than a minute. Although promising, its adoption in clinical settings will require further validation, but it represents progress toward more comprehensive and accessible medical examinations, as reported in the article published in
Nature Biomedical Engineering.