Neonatal seizures easier to track thanks to new imaging techniques

Using a non-invasive ultrasound technology, this is the first time such insight has been possible and it opens doors for researchers and the medical profession, offering a wide range of applications in neuroimaging and beyond.

The process was set out in a paper published in the journal ‘Science Transitional Medicine’, in which researchers explain that while Electroencephalography (EEG) and functional neuroimaging help us to understand brain function and abnormalities, there are challenges to the use of the equipment. These relate to the cost of the equipment and its size, which makes it tricky to use at a bedside.

‘Using a customised flexible and noninvasive headmount, we demonstrate in human neonates that real-time functional ultrasound imaging (fUSI) is feasible by combining simultaneous continuous video–electroencephalography (EEG) recording and ultrafast Doppler (UfD) imaging of the brain microvasculature,’ they write.

High-resolution, high-speed, safe and portable

The system is based on sonography, which uses ultrasound waves. This has never been applied to neuroscience before, but the EU-supported FUSIMAGINE research grant set out to use ultrafast ultrasound scanners, able to reach more than 10 000 frames per second (fps) compared to the usual 50 fps in conventional ultrasound scanners. By employing compounded plane wave transmissions the team demonstrates an up to 100-fold increase in the sensitivity of blood flow measurements.

The necessary increase in imaging sensitivity was achieved by combining ultrafast imaging rates and dedicated processing algorithms. Contrary to fMRI, functional ultrasound is light, portable, cheap. As such there are more environments in which it can be used. This opens it up to multiple clinical applications and suggests new paths for fundamental research.

Lead researcher Mickaël Tanter explains the technique, ‘In clinical diagnosis, fUS provides a unique, bedside neuro-imaging system of newborns’ brain activity through the fontanel window. Such real-time systems will help doctors to monitor, and gain a better understanding of, neonatal seizures and hemorrhages.’

Functional ultrasound imaging can also be used in adults, both in neurosurgery and for transcranial imaging, as new adaptive focusing techniques can overcome the strong aberrations induced by the skull bone on ultrasonic wavefronts.

FUSIMAGINE (A new neuroimaging modality: from bench to bedside) runs until 2019 and Mickaël Tanter hopes super-resolution ultrasound will permit the whole functional activity of the brain to be imaged at microscopic scales: opening up a new world for neuroscience.

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