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

Chen, Jean; Pike, G. Bruce

doi:10.1016/j.neuroimage.2010.07.003

Cited by 123 publications

(108 citation statements)

References 69 publications

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“…The improved agreement between CMRO 2 -estimates from alternative calibrations under a reduced flowvolume relationship (i.e., a = 0.20 vs. 0.38, see the section 'Assumed a-Parameter') forms an independent corroborating evidence of previous reports obtained from direct CBF and venous CBV measurement under graded visual and sensorimotor (a = 0.23 ± 0.05; Chen and Pike, 2009) as well as hypocapnic and HC stimulation (a = 0.18±0.02; Chen and Pike, 2010b). Because of the distinct vasoactive nature of the calibration gases used, the current study offers a complementary insight into the a-parameter.…”

Section: Optimized A-parametersupporting

confidence: 87%

Indication of BOLD-Specific Venous Flow-Volume Changes from Precisely Controlled Hyperoxic vs. Hypercapnic Calibration

Mark

Pike

2011

J Cereb Blood Flow Metab

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Deriving cerebral metabolic rate of oxygen consumption (CMRO 2 ) from blood oxygenation leveldependent (BOLD) signals involves a flow-volume parameter (a), reflecting total cerebral blood volume changes, and a calibration constant (M). Traditionally, the former is assumed a fixed value and the latter is measured under alterations in fixed inspired fractional concentrations of carbon dioxide. We recently reported on reductions in M-variability via precise control of end-tidal pressures of both hypercapnic (HC) and hyperoxic (HO) gases. In light of these findings, our aim was to apply the improved calibration alternatives to neuronal activation, making use of their distinct vasoactive natures to evaluate the a-value. Nine healthy volunteers were imaged at 3 T while simultaneously measuring BOLD and arterial spin-labeling signals during controlled, graded, HC, and HO, followed by visual (VC) and sensorimotor cortices (SMC) activation. On the basis of low M-and CMRO 2 -variability, the comparison of these calibration alternatives accurately highlighted a reduced venous flow-volume relationship (a = 0.16 ± 0.02, with a VC = 0.12 ± 0.04, and a SMC = 0.20±0.02), as appropriate for BOLD modeling.

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Section: Optimized A-parametersupporting

confidence: 87%

Indication of BOLD-Specific Venous Flow-Volume Changes from Precisely Controlled Hyperoxic vs. Hypercapnic Calibration

Mark

Pike

2011

J Cereb Blood Flow Metab

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“…In the literature, healthy young adults are not expected to present with negative CVR values during a CO 2 challenge (Leung et al, 2016), except for in the ventricles and other areas occupied by cerebrospinal fluid (Blockley et al, 2011;Ravi et al, 2016). This has been the case in our own work as well (Chen and Pike, 2010b;Halani et al, 2015). Therefore, as a last step, all negative CVR values were clamped to zero.…”

mentioning

confidence: 60%

“…This method was chosen to maximize steadystate PETCO 2 -targetting accuracy and stability while minimizing PETO 2 confounds during CO 2 -based CVR measurements (Chen and Pike, 2010b;Halani et al, 2015;Mark et al, 2010;Prisman et al, 2008), and is the most established method clinically (Pillai and Mikulis, 2015).…”

Section: Bmentioning

confidence: 99%

“…PETCO 2 changes can be induced through manually adjusted administration of blended gases (Bandettini and Wong, 1997 ;Cohen et al, 2004;Yezhuvath et al, 2009), end-tidal forcing (Poulin et al, 1996) or more recently, computerized PETCO 2 targeting (Conklin et al, 2011;Han et al, 2011;Mandell et al, 2011;Mandell et al, 2008;Mark et al, 2010;Mikulis et al, 1989;Mutch et al, 2012;Prisman et al, 2008;Slessarev et al, 2007;Spano et al, 2013;Vesely et al, 2001). The latter method provides immediate and robust PETCO 2 changes, and we have used it extensively in our own work (Chen and Pike, 2010a;Chen and Pike, 2010b;Halani et al, 2015). More recently, breath-holding (Murphy et al, 2011) and deep breathing (Bright et al, 2009) have been proposed as alternatives to modulate PETCO 2 , although CO 2 manipulation through breathing circuits is still the dominating approach.…”

Section: Introductionmentioning

confidence: 99%

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Quantitative mapping of cerebrovascular reactivity using resting-state BOLD fMRI: Validation in healthy adults

2016

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In conventional neuroimaging, cerebrovascular reactivity (CVR) is quantified primarily using the blood-oxygenation level-dependent (BOLD) functional MRI (fMRI) signal, specifically, as the BOLD response to intravascular carbon dioxide (CO 2 ) modulations, in units of [%ΔBOLD/ mmHg]. While this method has achieved wide appeal and clinical translation, the tolerability of CO 2 -related tasks amongst patients and the elderly remains a challenge in more routine and largescale applications. In this work, we propose an improved method to quantify CVR by exploiting intrinsic fluctuations in CO 2 and corresponding changes in the resting-state BOLD signal (rsqCVR). Our rs-qCVR approach requires simultaneous monitoring of PETCO 2 , cardiac pulsation and respiratory volume. In 16 healthy adults, we compare our quantitative CVR estimation technique to the prospective CO 2 -targeting based CVR quantification approach (qCVR, the "standard"). We also compare our rs-CVR to non-quantitative alternatives including the restingstate fluctuation amplitude (RSFA), amplitude of low-frequency fluctuation (ALFF) and globalsignal regression. When all subjects were pooled, only RSFA and ALFF were significantly associated with qCVR. However, for characterizing regional CVR variations within each subject, only the PETCO 2 -based rs-qCVR measure is strongly associated with standard qCVR in 100% of the subjects (p<=0.1). In contrast, for the more qualitative CVR measures, significant withinsubject association with qCVR was only achieved in 50-70% of the subjects. Our work establishes the feasibility of extracting quantitative CVR maps using rs-fMRI, opening the possibility of mapping functional connectivity and qCVR simultaneously.

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“…Since 'arterial' and 'venous' blood portions are here considered based on their oxygenation level and not on anatomical structure, the terms 'arterial' and 'venous' are denoted in quotes. The separate consideration of 'arterial' and 'venous' CBV change based on their T 2 * can be regarded as distinguishing between BOLDspecific and BOLD-nonspecific CBV changes (Chen and Pike, 2010).…”

Section: Theory Of Bold-dependent T 2 * In Ss-si-vasomentioning

confidence: 99%

Investigation of the neurovascular coupling in positive and negative BOLD responses in human brain at 7T

et al. 2014

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

Cited by 123 publications

References 69 publications

Indication of BOLD-Specific Venous Flow-Volume Changes from Precisely Controlled Hyperoxic vs. Hypercapnic Calibration

Indication of BOLD-Specific Venous Flow-Volume Changes from Precisely Controlled Hyperoxic vs. Hypercapnic Calibration

Quantitative mapping of cerebrovascular reactivity using resting-state BOLD fMRI: Validation in healthy adults

Investigation of the neurovascular coupling in positive and negative BOLD responses in human brain at 7T

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