Functional ultrasound microscopy: probing the activity of the whole brain at the microscopic level

Functional ultrasound localization microscopy of the rat brain (Photo: Alexandre Dizeux / Physics for Medicine Paris) - Ultrasound is transforming the field of neuroimaging, thanks to technological advances made over the last decade by the Physics for Medicine laboratory (Inserm, ESPCI Paris - PSL, CNRS). The introduction of functional ultrasound imaging (fUS) in 2009 provided neuroscientists with a unique technology - portable, easy to use, and reasonably priced - to visualize brain activity with high sensitivity. In 2015, another method, called ultrasound localization microscopy (ULM), produced novel images of the cerebral vascular network, revealing blood vessels just a few micrometers in diameter. Now, in 2022, research teams in the Physics for Medicine lab are achieving even more dramatic results by combining the advantages of both methods: functional ultrasound localization microscopy (fULM) captures brain activity across the entire brain at the microscopic scale. The study has just been published in the journal Nature Methods . It opens up major future prospects in the clinic for the diagnosis of cerebrovascular pathologies, such as strokes, all small vessel diseases, and other diseases.It opens up major future clinical perspectives for the diagnosis of cerebrovascular pathologies, such as strokes, all diseases of small vessels, risks of aneurysm rupture or vascular alterations present very early in neurodegenerative diseases such as Alzheimer's disease. Ultrasound scanners - imaging systems based on the use of ultrasound waves - allow organs to be observed through the skin, and their use is therefore widespread in diagnostic imaging and medical monitoring, particularly in obstetrics and cardiology.