A proof-of-concept study, funded by the National Institutes of Health and conducted by researchers from the Keck School of Medicine of USC and Caltech, has demonstrated a new noninvasive technique for quickly collecting 3D images of the human body. This technology, named RUS-PAT, combines rotational ultrasound tomography (RUST) and photoacoustic tomography (PAT) to simultaneously image both tissue and blood vessels from head to foot.
Current Imaging Limitations
Existing medical imaging techniques, such as ultrasound, X-ray, computed tomography (CT), and magnetic resonance imaging (MRI), have limitations regarding cost, scan time, imaging depth, field of view, and detail.
How RUS-PAT Works
- RUST: Similar to standard ultrasound, RUST uses an arc of detectors to direct sound waves and create a 3D volumetric image of body tissues.
- PAT: Directs a laser light beam at the same area, which is absorbed by hemoglobin in the blood. The vibrating hemoglobin molecules produce ultrasonic frequencies, measured by the same detectors to create 3D images of blood vessels.
- The system can capture both tissue structure and blood vessels across a region up to 10 centimeters wide in approximately 10 seconds.
Potential Benefits
RUS-PAT offers several advantages:
- Lower manufacturing cost compared to MRI scanners.
- Avoids the ionizing radiation used in X-ray and CT scans.
- Provides more sophisticated images than conventional ultrasound.
Clinical Applications and Challenges
Researchers used the RUS-PAT system to image the brain (in patients with temporary skull removal), breast, hand, and foot, demonstrating its broad applicability.
- Brain imaging: Relevant for stroke, traumatic brain injury, and neurological diseases.
- Breast imaging: Supports detection and care for a common cancer.
- Foot imaging: Could aid in diagnosing and managing diabetic foot complications and venous disease.
Challenges remain, particularly with brain imaging, as the human skull distorts signals. Further refinements are needed to ensure consistent image quality before the technology is ready for clinical use.