TY - JOUR
T1 - Measuring arterial and tissue responses to functional challenges using arterial spin labeling
AU - Ho, Yi Ching Lynn
AU - Petersen, Esben Thade
AU - Golay, Xavier
N1 - Funding Information:
The authors thank Dr Ivan Zimine for valuable technical assistance, Dr Albert Gjedde for useful discussions and Dr Yih-Yian Sitoh for administrative assistance. This study was supported by a grant from the National Medical Research Council, NMRC/0855/2004. Y-C. L. Ho is supported in part by the Singapore Millennium Foundation.
PY - 2010/1/1
Y1 - 2010/1/1
N2 - The measurement of cerebral blood flow (CBF) in functional MRI studies that aim for non-invasive, quantitative and reliable measurements is a challenge. Here, we tested the feasibility of a recently developed, model-free CBF technique to study vascular dynamics upon functional challenges. Multiple inversion time-point signals were measured from arterial and tissue compartments, allowing for the calculation of CBF through a process of deconvolution. Using graded visual stimulation known to produce increasing hemodynamic responses, we recorded significant and graded ΔCBF and Δτm (microvascular arrival time change) that were highly comparable to those estimated by a standard 3-parameter fit based on the general kinetic model, though the absolute values had weaker agreement. Estimated arterial blood volumes (excluding substantial arteriolar contribution) did not show significant change with visual stimulation. Bolus arrival times in the microvascular compartment shortened more as compared to the arrival times from the arterial compartment during visual stimulation, suggesting larger involvement of the microvasculature in local neuronal response. While there are limitations, the model-free analysis method has the potential to offer useful vascular information in fMRI studies.
AB - The measurement of cerebral blood flow (CBF) in functional MRI studies that aim for non-invasive, quantitative and reliable measurements is a challenge. Here, we tested the feasibility of a recently developed, model-free CBF technique to study vascular dynamics upon functional challenges. Multiple inversion time-point signals were measured from arterial and tissue compartments, allowing for the calculation of CBF through a process of deconvolution. Using graded visual stimulation known to produce increasing hemodynamic responses, we recorded significant and graded ΔCBF and Δτm (microvascular arrival time change) that were highly comparable to those estimated by a standard 3-parameter fit based on the general kinetic model, though the absolute values had weaker agreement. Estimated arterial blood volumes (excluding substantial arteriolar contribution) did not show significant change with visual stimulation. Bolus arrival times in the microvascular compartment shortened more as compared to the arrival times from the arterial compartment during visual stimulation, suggesting larger involvement of the microvasculature in local neuronal response. While there are limitations, the model-free analysis method has the potential to offer useful vascular information in fMRI studies.
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U2 - 10.1016/j.neuroimage.2009.07.040
DO - 10.1016/j.neuroimage.2009.07.040
M3 - Article
C2 - 19635576
AN - SCOPUS:70349968265
SN - 1053-8119
VL - 49
SP - 478
EP - 487
JO - NeuroImage
JF - NeuroImage
IS - 1
ER -