Abstract:
Studying brain-wide hemodynamic responses to different stimuli at high spatiotemporal resolutions can help gain new insights into the mechanisms of neuro- diseases and -disorders. Nonetheless, this task is challenging, primarily due to the complexity of neurovascular coupling, which encompasses interdependent hemodynamic parameters including cerebral blood volume (CBV), cerebral blood flow (CBF), and cerebral oxygen saturation (SO2). The current brain imaging technologies exhibit inherent limitations in resolution, sensitivity, and imaging depth, restricting their capacity to comprehensively capture the intricacies of cerebral functions. To address this, a multimodal functional ultrasound and photoacoustic (fUSPA) imaging platform is reported, which integrates ultrafast ultrasound and multispectral photoacoustic imaging methods in a compact head-mountable device, to quantitatively map individual dynamics of CBV, CBF, and SO2 as well as contrast agent enhanced brain imaging at high spatiotemporal resolutions. Following systematic characterization, the fUSPA system is applied to study brain-wide cerebrovascular reactivity (CVR) at single-vessel resolution via relative changes in CBV, CBF, and SO2 in response to hypercapnia stimulation. These results show that cortical veins and arteries exhibit differences in CVR in the stimulated state and consistent anti-correlation in CBV oscillations during the resting state, demonstrating the multiparametric fUSPA system\'s unique capabilities in investigating complex mechanisms of brain functions.
摘要:
在高时空分辨率下研究全脑对不同刺激的血液动力学反应可以帮助获得对神经疾病和障碍机制的新见解。尽管如此,这项任务具有挑战性,主要是由于神经血管耦合的复杂性,包括相互依赖的血液动力学参数,包括脑血容量(CBV),脑血流量(CBF),和脑氧饱和度(SO2)。当前的脑成像技术在分辨率方面表现出固有的局限性,灵敏度,和成像深度,限制了他们全面捕捉复杂大脑功能的能力。为了解决这个问题,报道了一种多模态功能超声和光声(fUSPA)成像平台,在紧凑的头戴式设备中集成了超快超声和多光谱光声成像方法,定量绘制CBV的个体动力学,CBF,和SO2以及造影剂以高时空分辨率增强脑成像。在系统表征之后,fUSPA系统用于通过CBV的相对变化在单血管分辨率下研究全脑脑血管反应性(CVR),CBF,和SO2对高碳酸血症刺激的反应。这些结果表明,皮质静脉和动脉在刺激状态下表现出CVR的差异,在静息状态下表现出CBV振荡的一致反相关,展示了多参数fUSPA系统在研究脑功能复杂机制方面的独特能力。