A three-dimensional single-scan approach for the measurement of changes in cerebral blood volume, blood flow, and blood oxygenation-weighted signals during functional stimulation

- A 3D MRI acquisition strategy to measure CBV, CBF, and BOLD signal changes during visual stimulation in a single scan is proposed.
- The activation pattern and quantitative fMRI results during visual stimulation are all comparable between the proposed concurrent imaging method and the conventionally applied separate scans.
- This approach is expected to provide a useful alternative for quantitative BOLD fMRI studies, and would shorten the total scan time and reduce sensitivity to temporal variations in physiological or neuronal responses.

The blood-oxygenation-level-dependent (BOLD) effect reflects ensemble changes in several physiological parameters such as cerebral blood volume (CBV), blood flow (CBF), and cerebral metabolic rate of oxygen (CMRO2). Quantitative BOLD approaches have been developed to estimate CMRO2 dynamics from BOLD, CBF and CBV responses, generally using separate scans. The ability to detect changes in these parameters in a single scan would shorten the total scan time and reduce temporal variations in physiology or neuronal responses. Here, an acquisition strategy, named 3D TRiple-acquisition after Inversion Preparation (3D-TRIP), is demonstrated for 3D acquisition of CBV, CBF, and BOLD signal changes in a single scan by incorporating VASO, FAIR-ASL and T2-prepared BOLD fMRI methods. Using a visual stimulation paradigm, we demonstrate that the activation patterns, relative signal changes, temporal signal-to-noise ratio (tSNR), contrast-to-noise ratio (CNR), and estimated CMRO2 changes during visual stimulation are all comparable between the concurrent imaging proposed here and the separate scans conventionally applied. This approach is expected to provide a useful alternative for quantitative BOLD fMRI studies where information about oxygen metabolism alterations can be extracted from changes in hemodynamic signals associated with CBV, CBF, and blood oxygenation.