Jun Hua1, Robert Stevens1, Manus
J. Donahue1,2, Alan J. Huang1, James J. Pekar1,
Peter C.M. van Zijl1
1Department of Radiology, The Johns
Hopkins University, Baltimore, MD, United States; 2Department of
Clinical Neurology, Oxford University, Oxford, United Kingdom
Changes
in CBF/CBV/arterial-CBV(CBVa)/post-arterial-CBV(CBVpa)
were measured in human brain during breath-hold and visual stimulation.
δCBV/CBV was larger during breath-hold (54.9+/-5.8%) than visual stimulation
(28.2+/-5.2%), a difference primarily originating from δCBVpa/CBVpa
(54.5+/-4.9% vs. 22.2+/-3.8%); δCBVa/CBVa
(53+/-6%) and δCBF/CBF (61+/-7%) were comparable in both tasks. During
breath-hold, vasodilation distributed proportionally among arterial and
post-arterial compartments, whereas, during visual stimulation, relative
change in CBVa was greater than that in CBVpa. Our data
indicate that the coupling between arterial-CBV and CBF was largely preserved
during both tasks (rCBVa=rCBF0.86+/-0.05), while the relationship
between total-CBV and CBF was substantially different between breath-hold
(rCBV=rCBF0.90+/-0.05) and visual (rCBV=rCBF0.52+/-0.04)
stimulation.
Keywords