Simultaneous acquisition of cerebral blood volume-, blood flow-, and blood oxygenation-weighted MRI signals at ultra-high magnetic field.

Purpose: Yang et al. proposed an MRI technique for the simultaneous acquisition of cerebral blood volume (CBV), cerebral blood flow (CBF), and blood oxygenation level-dependent (BOLD)-weighted MRI signals (9). The purpose of this study was to develop modified version of the Yang sequence, which utilizes the advantages of 7 Tesla, leading to a robust and reliable MRI sequence.

Regional reproducibility of calibrated BOLD functional MRI: implications for the study of cognition and plasticity.

Calibrated BOLD fMRI is a promising alternative to the classic BOLD contrast due to its reduced venous sensitivity and greater physiological specificity. The delayed adoption of this technique for cognitive studies may stem partly from a lack of information on the reproducibility of these measures in the context of cognitive tasks. In this study we have explored the applicability and reproducibility of a state-of-the-art calibrated BOLD technique using a complex functional task at 7 tesla.

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

Decreases in stimulus-dependent blood oxygenation level dependent (BOLD) signal and their underlying neurovascular origins have recently gained considerable interest. In this study a multi-echo, BOLD-corrected vascular space occupancy (VASO) functional magnetic resonance imaging (fMRI) technique was used to investigate neurovascular responses during stimuli that elicit positive and negative BOLD responses in human brain at 7 T. Stimulus-induced BOLD, cerebral blood volume (CBV), and cerebral blood flow (CBF) changes were measured and analyzed in 'arterial' and 'venous' blood compartments in macro- and microvasculature.

Using carbogen for calibrated fMRI at 7Tesla: comparison of direct and modelled estimation of the M parameter.

Task-evoked changes in cerebral oxygen metabolism can be measured using calibrated functional Magnetic Resonance Imaging (fMRI). This technique requires the use of breathing manipulations such as hypercapnia, hyperoxia or a combination of both to determine a calibration factor M. The M-value is usually obtained by extrapolating the BOLD signal measured during the gas manipulation to its upper theoretical physiological limit using a biophysical model.

Slab-selective, BOLD-corrected VASO at 7 Tesla provides measures of cerebral blood volume reactivity with high signal-to-noise ratio.

Purpose: MRI methods sensitive to functional changes in cerebral blood volume (CBV) may map neural activity with better spatial specificity than standard functional MRI (fMRI) methods based on blood oxygen level dependent (BOLD) effect. The purpose of this study was to develop and investigate a vascular space occupancy (VASO) method with high sensitivity to CBV changes for use in human brain at 7 Tesla (T).

Methods: To apply 7T VASO, several high-field-specific obstacles must be overcome, e.

Cerebral blood volume changes during brain activation.

Cerebral blood volume (CBV) changes significantly with brain activation, whether measured using positron emission tomography, functional magnetic resonance imaging (fMRI), or optical microscopy. If cerebral vessels are considered to be impermeable, the contents of the skull incompressible, and the skull itself inextensible, task- and hypercapnia-related changes of CBV could produce intolerable changes of intracranial pressure. Because it is becoming clear that CBV may be useful as a well-localized marker of neural activity changes, a resolution of this apparent paradox is needed.