Abstract
Purpose We investigate the influence of moving blood-attenuation effects when using "delay alternating with nutation for tailored excitation" (DANTE) pulses in conjunction with blood oxygen level dependent (BOLD) of functional MRI (fMRI) at 3 T. Based on the effects of including DANTE pulses, we propose quantification of cerebral blood volume (CBV) changes following functional stimulation. Methods Eighteen volunteers in total underwent fMRI scans at 3 T. Seven volunteers were scanned to investigate the effects of DANTE pulses on the fMRI signal. CBV changes in response to visual stimulation were quantified in 11 volunteers using a DANTE-prepared dual-echo EPI sequence. Results The inflow effects from flowing blood in arteries and draining vein effects from flowing blood in large veins can be suppressed by use of a DANTE preparation module. Using DANTE-prepared dual-echo EPI, we quantitatively measured intravascular-weighted microvascular CBV changes of 25.4%, 29.8%, and 32.6% evoked by 1, 5, and 10 Hz visual stimulation, respectively. The extravascular fraction ( increment S/S)(extra) at TE = 30 ms in total BOLD signal was determined to be 64.8 +/- 3.4%, which is in line with previous extravascular component estimation at 3 T. Results show that the microvascular CBV changes are linearly dependent on total BOLD changes at TE = 30 ms with a slope of 0.113, and this relation is independent of stimulation frequency and subject. Conclusion The DANTE preparation pulses can be incorporated into a standard EPI fMRI sequence for the purpose of minimizing inflow effects and reducing draining veins effects in large vessels. Additionally, the DANTE-prepared dual-echo EPI sequence is a promising fast imaging tool for quantification of intravascular-weighted CBV change in the microvascular space at 3 T.
Original language | English |
---|---|
Pages (from-to) | 1846-1862 |
Number of pages | 17 |
Journal | Magnetic Resonance in Medicine |
Volume | 87 |
Issue number | 4 |
Early online date | 24 Nov 2021 |
DOIs | |
Publication status | Published - Apr 2022 |
Keywords
- ACTIVATION
- BOLD
- DANTE-prepared dual-echo EPI
- FLOW
- FMRI
- FUNCTIONAL MRI
- HUMAN BRAIN
- OXYGEN-METABOLISM
- PERFUSION
- SIGNAL
- SPIN-ECHO
- VASO
- VELOCITY
- blood signal suppression
- fMRI
- quantification of CBV changes