Cerebral hemodynamics in a healthy population measured by dynamic susceptibility contrast MR imaging

Abstract

Cerebral hemodynamics can be assessed with DSC MRI. Age itself seems to have only a marginal effect on cerebral perfusion in healthy population.

A Novel Method to Derive Separate Gray and White Matter Cerebral Blood Flow Measures from MR Imaging of Acute Ischemic Stroke Patients

“…We also simplified tissue segmentation, combining all GM into a single category. Studies have suggested, however, that cortical and subcortical GM have different perfusion characteristics and that regional cortical CBF variations exist (Leenders et al, 1990;Helenius et al, 2003). Ultimately a brain atlas registered to images such as IRSEPI could provide detailed comparisons of GM and WM thresholds in different anatomic or even functional regions (Menezes et al, 2003).…”

“…Human MR stroke studies to date have not attempted to differentiate between gray matter (GM) and white matter (WM) and instead have assumed that all brain tissues have the same perfusion thresholds. Evidence from both human and animal studies, however, suggest that GM has higher blood flow requirements than WM in both normal (Helenius et al, 2003;Leenders et al, 1990) and ischemic brain (Marcoux et al, 1982). Both the depth and the duration of ischemia at which damage occurs likely differ between GM and WM.…”

Confirming white matter fMRI activation in the corpus callosum: Co-localization with DTI tractography

“…Traditionally, it has been thought that fMRI is restricted to gray matter due to the relatively greater blood flow and volume in gray matter ( [Helenius et al, 2003], [Preibisch and Haase, 2001], [Rostrup et al, 2000], [Van der Zande et al, 2005] and [Wise et al, 2004]). In addition, it is thought that the primary source of fMRI signals are hemodynamic responses to post-synaptic potentials, which mainly occur in gray matter (e.g., Logothetis et al, 2001 I pr Logothetis and Wandell, 2004, p. 755).…”

Functional mapping in the corpus callosum: A 4T fMRI study of white matter

“…There are two main reasons for the controversy: 1) BOLD signals rely in part on relatively small fluctuations in cerebral blood volume and flow, which are then 3-6 times lower in white matter ( [Preibisch & Haase, 2001], [Rostrup et al, 2000], [Helenius et al, 2003], [van der Zande et al, 2005] and [Wise et al, 2004]); and 2) the primary source of fMRI signal is thought to arise from post-synaptic potentials (which occur mainly in gray matter) as opposed to action potentials (Logothetis et al, 2001). To put the situation in context, of the 254 287 fMRI studies that have been published to date (according to PubMed at the time this paper was written), there are only nine reporting activation in white matter to our knowledge ( [Tettamanti et al, 2002], [Omura et al, 2004], [Weber et al, 2005], [ and [Mazerolle et al, 2010]).…”