Overcoming the skull barrier for noninvasive transcranial functional ultrasound imaging in marmosets

Functional ultrasound (fUS) imaging enables high-resolution mapping of brain hemodynamics but is limited in primates by acoustic attenuation of the cranium. With topical application of ethylenediaminetetraacetic acid (EDTA), we were able to visualized cortical and deep vasculature in marmoset brains. We localized robust, stimulus-locked blood flow changes in cortical and subcortical regions contralateral to peripheral tactile stimulation. Beyond stimulus-evoked responses, resting-state cerebral blood flow also varied with the depth of isoflurane anesthesia. These findings advance translational ultrasound neuroimaging by offering a non-destructive alternative to a craniotomy.