MRI measurement of the BOLD-specific flow-volume relationship during hypercapnia and hypocapnia in humans

作者：Chen J Jean^*; Pike G Bruce

来源：NeuroImage, 2010, 53(2): 383-391.

DOI：10.1016/j.neuroimage.2010.07.003

• Cerebral blood flow
• Venous cerebral blood volume
• Grubb's relationship
• Hypercapnia
• Hypocapnia
• Respiract
• Sequential gas delivery
• FMRI
• VERVE
• arterial spin labeling
• QUIPSS II

It is widely assumed in fMRI that the relationship between cerebral blood flow (CBF) and volume (CBV) changes observed during end-tidal CO(2) (PETCO(2)) perturbations is equivalent to that elicited by neuronal activation. This assumption has been validated in PET studies insofar as relating total flow to total CBV changes, but remains unconfirmed for venous CBV changes, which pertains to the primary vascular compartment modulating the BOLD signal In this study, we measured CBF and venous CBV changes in healthy subjects in response to graded hypercapnia and hypocapnia, induced using computerized end-tidal CO(2) targeting, with a Delta PETCO(2) range of between -6 and +9 mm Hg Hypercapnia was found to elicit robust increases in CBF and venous CBV, while hypocapnia produced decreases in both We used steady-state flow and volume changes to estimate the power-law relationship for cortical and subcortical brain regions, and did not observe significant difference between the two. The combined fit resulted in a power coefficient of 0 18 +/- 0 02. substantially lower than Grubb's coefficient of 0.38, but comparable to previous observations during neuronal activation.

• 出版日期2010-11-1