Science & Research | November 20th, 2025
The fUSiON (fast UltraSound integrated with Optical imaging in the Newborn) project
Acute brain injury in newborns is a major cause of death and lifelong disability, particularly in preterm infants who remain at high risk despite improved survival rates. Current structural imaging methods such as cranial ultrasound and MRI are limited in their ability to predict neurodevelopmental outcomes. This project, funded by an EU Marie Skłodowska-Curie post-doctoral fellowship (Dr Flora Faure) and NIHR HealthTech Research Centre for Brain Injury PhD studentship (Nina Sobierajska), aims to develop a portable, multimodal functional brain imaging system capable of high-resolution, bedside assessment of brain activity. By capturing functional, rather than purely structural, information, it aims to improve early identification of infants at risk of adverse outcomes, enhance understanding of how brain activity develops after injury, and enable more targeted early interventions to improve long-term prognosis.
The system combines two complementary technologies—high-density diffuse optical tomography (HD-DOT) and functional ultrasound (fUS) and results from collaborations between engineers, physicists and clinicians in London, Paris and Cambridge.
HD-DOT is an extension of functional near-infrared spectroscopy (fNIRS), using near-infrared light to detect changes in oxygenated and deoxygenated haemoglobin, reflecting regional brain oxygenation. By using multiple overlapping light sources and detectors and applying advanced image reconstruction algorithms, HD-DOT generates three-dimensional, millimetre-scale maps of cortical activity.
Functional ultrasound (fUS), in contrast, uses ultrafast plane-wave imaging—up to 10,000 frames per second—to visualise dynamic blood flow in fine cerebral vessels with very high spatial and temporal precision. fUS can image deep brain structures such as the thalamus and basal ganglia through the infant's fontanelle, providing insight into subcortical activity.
Each technology has complementary strengths and limitations: HD-DOT can map cortical but not deep brain regions, while fUS can image deep structures but has limited cortical coverage. Combining the two will therefore enable comprehensive, high-resolution imaging of both cortical and subcortical brain function.
We have carried out preliminary studies on both the postnatal ward and neonatal unit in the Rosie Hospital and demonstrated that the signal obtained using HD-DOT correlates well with fUS; this paves the way for further studies investigating intrinsic brain activity (at rest) as well as in response to external stimuli, across different gestational ages and cerebral pathologies.
Click here to read the BBC article on the fUSiON project.