All-optical ultrasound technology can provide real-time 2D imaging of biological tissue with imaging capabilities comparable to those of an electronic high-frequency ultrasound system, and it could even be used safely with MRI, according to research published in the August issue of Biomedical Optics Express.
Researchers from University College London in the U.K. have developed a prototype of an all-optical ultrasound system using a spatially extended nanocomposite optical ultrasound generator, a fiber-optic acoustic receiver, and what they call "eccentric illumination." In testing on a deceased zebra fish as well as a pig artery manipulated to emulate the dynamics of pulsing blood, the system was capable of a sustained frame rate of 15 Hz, a dynamic range of 30 decibels, a penetration depth of 6 mm, and a resolution of 75 x 100 micrometers.
What's more, the system doesn't require electronic components in the imaging probe, enabling its use in the MRI environment and providing physicians with a more comprehensive view of an area of interest such as a tumor or blood vessel, according to the researchers.
"All-optical ultrasound imaging probes have the potential to revolutionize image-guided interventions," said Erwin Alles, PhD, in a statement. "A lack of electronics and the resulting MRI compatibility will allow for true multimodality image guidance, with probes that are potentially just a fraction of the cost of conventional electronic counterparts."
The device uses lightbeam scanning mirrors designed to improve image quality and acquire images in different modes. When using the system clinically, doctors could rapidly toggle between modes on a single instrument, according to the researchers (Biomed Opt Express, August 2018, Vol. 9:8, pp. 3481-3494).
While optical ultrasound systems have previously been shown to produce high-quality 2D and 3D images, image acquisition took hours -- too slow to be used in a clinical setting. However, the new prototype can acquire and display images at video rates, according to the group.
"Through the combination of a new imaging paradigm, new optical ultrasound generating materials, optimized ultrasound source geometries, and a highly sensitive fiber-optic ultrasound detector, we achieved image frame rates that were up to three orders of magnitude faster than the current state of the art," Alles said.
In an effort to adapt the technology for clinical use, the researchers are now working to develop a long, flexible imaging probe for free-hand operation. Miniaturized versions for endoscopic applications are also being developed.
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&fit=crop&h=100&q=70&w=100)
![Examples of ultrasound findings and techniques. (A) Images in a 39-year-old male patient with a mass in the left thigh. The mass is heterogeneous on the B-mode US image (compared with the patient in D) and showed increased microvascularity (superb microvascular imaging [SMI]) and shear-wave elastography (SWE) values. Undifferentiated pleomorphic sarcoma was diagnosed at biopsy (with pleomorphic rhabdomyosarcoma in surgical specimen). (B) Images in an 18-year-old male patient with a mass in the left leg. The mass is hypoechoic on the B-mode image, with no other findings suggestive of malignancy. The lesion is in contact with the cortex of the tibia, which is slightly irregular. CT revealed a doubtful anteromedial tibial erosion. The microvascular study demonstrated high vascularization, suggestive of malignancy. Periosteal Ewing sarcoma was diagnosed with both histologic and immunohistochemical confirmation. (C) Images in a 69-year-old female patient with a lump growing on the outside of the left leg. Multiple SWE examinations were performed (please note the high values obtained in the measurements, whereas the color map highlights the stiffness relative to adjacent tissues). SMI showed areas of increased vascularization to target for sampling. Undifferentiated spindle cell sarcoma was diagnosed at biopsy, with residual leiomyosarcoma in the surgical specimen after neoadjuvant therapy. (D) Images in a 56-year-old female patient with a mass in the right thigh. The mass is heterogeneous at both B-mode ultrasound (similar to patient A) and MRI (coronal T2-weighted spectral attenuated inversion recovery [SPAIR]; T1-weighted pre-contrast and postcontrast imaging), which even shows uptake after the administration of paramagnetic contrast material, which is traditionally suggestive of malignancy. Low values at SMI and elastography are suggestive of benignity. Spindle cell lipoma was diagnosed at biopsy, with atypical spindle cell lipomatous tumor in the surgical specimen.](https://img.auntminnieeurope.com/mindful/smg/workspaces/default/uploads/2026/08/images-radiol250278fig2.APCFLSvX6p.jpg?auto=format%2Ccompress&dpr=2&fit=crop&h=167&q=70&w=250)
