Abstract
Cerebral blood flow (CBF) represents the local blood supply to the brain, and it can be considered a proxy for neuronal activation. Independent component analysis (ICA) can be applied to CBF maps to derive patterns of spatial covariance across subjects. In the present study, we aimed to assess the consistency of the independent components derived from CBF maps (CBF-ICs) across a cohort of 92 healthy individuals. Moreover, we evaluated the spatial similarity of CBF-ICs with respect to resting state networks (RSNs) and vascular territories (VTs). The data were acquired on a 1.5 T scanner using arterial spin labeling (ASL) and resting state functional magnetic resonance imaging. Similarity was assessed considering the entire ASL dataset. Consistency was evaluated by splitting the dataset into subsamples according to three different criteria: (1) random split of age and sex-matched subjects, (2) elderly vs. young, and (3) males vs. females. After standard preprocessing, ICA was performed. Both consistency and similarity were assessed by visually comparing the CBF-ICs. Then, the degree of spatial overlap was quantified with Dice Similarity Coefficient (DSC). Frontal, left, and right occipital, cerebellar, and thalamic CBF-ICs were consistently identified among the subsamples, independently of age and sex, with fair to moderate overlap (0.2 < DSC ≤ 0.6). These regions are functional hubs, and their involvement in many neurodegenerative pathologies has been observed. As slight to moderate overlap (0.2< DSC < 0.5) was observed between CBF-ICs and some RSNs and VTs, CBF-ICs may mirror a combination of both functional and vascular brain properties.
Highlights
Arterial spin labeling (ASL) is a widely used noninvasive magnetic resonance imaging (MRI)technique which provides quantitative and biologically meaningful maps of cerebral blood flow (CBF) by using blood as an endogenous contrast agent
Blood Oxygen Level-Dependent (BOLD) signal is closely associated with CBF due to the neurovascular coupling, we aimed to assess the degree of similarity between the CBF-independent components (ICs) and the well-known spatial patterns of resting state networks (RSNs) derived from BOLD-rsfMRI
Some CBF-ICs were robustly identified across healthy individuals (HI) subgroups and partially mirrored RSNs and vascular territories (VTs), supporting the idea that CBF-ICs may capture both functional and vascular network information
Summary
Arterial spin labeling (ASL) is a widely used noninvasive magnetic resonance imaging (MRI)technique which provides quantitative and biologically meaningful maps of cerebral blood flow (CBF) by using blood as an endogenous contrast agent. CBF is closely linked to cerebral metabolism and can be considered a surrogate measure of brain activity; it indirectly reflects brain vascular health. For these reasons, CBF has been investigated both in physiological and pathological conditions. Associations between brain perfusion and either disability or cognitive impairment were observed even in the early disease stages of PD [9,10], as well as in subjects with MS [11,12] and AD [13]. Measurement of CBF may be capable of capturing either early metabolic/functional or vascular changes underlying neurodegeneration
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
