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Calibrated bold fMRI with an optimized ASL-BOLD dual-acquisition sequence
| Content Provider | Scilit |
|---|---|
| Author | Fernández-Seara, María A. Rodgers, Zachary B. Englund, Erin K. Wehrli, Felix W. |
| Copyright Year | 2016 |
| Description | Journal: NeuroImage Calibrated fMRI techniques estimate task-induced changes in the cerebral metabolic rate of oxygen (CMRO2) based on simultaneous measurements of cerebral blood flow (CBF) and blood-oxygen-level-dependent (BOLD) signal changes evoked by stimulation. To determine the calibration factor M (corresponding to the maximum possible BOLD signal increase), BOLD signal and CBF are measured in response to a gas breathing challenge (usually CO2 or O2). Here we describe an ASL dual-acquisition sequence that combines a background-suppressed 3D-GRASE readout with 2D multi-slice EPI. The concatenation of these two imaging sequences allowed separate optimization of the acquisition for CBF and BOLD data. The dual-acquisition sequence was validated by comparison to an ASL sequence with a dual-echo EPI readout, using a visual fMRI paradigm. Results showed a 3-fold increase in temporal signal-to-noise ratio (tSNR) of the ASL time-series data while BOLD tSNR was similar to that obtained with the dual-echo sequence. The longer TR of the proposed dual-acquisition sequence, however, resulted in slightly lower T-scores (by 30%) in the BOLD activation maps. Further, the potential of the dual-acquisition sequence for M-mapping on the basis of a hypercapnia gas breathing challenge and for quantification of CMRO2 changes in response to a motor activation task was assessed. In five subjects, an average gray matter M-value of 8.71±1.03 and fractional changes of CMRO2 of 12.5±5% were found. The new sequence remedies the deficiencies of prior combined BOLD-ASL acquisition strategies by substantially enhancing perfusion tSNR, which is essential for accurate BOLD calibration. |
| Related Links | http://europepmc.org/articles/pmc5159288?pdf=render https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5159288/pdf |
| Ending Page | 482 |
| Page Count | 9 |
| Starting Page | 474 |
| ISSN | 10538119 |
| DOI | 10.1016/j.neuroimage.2016.08.007 |
| Journal | NeuroImage |
| Volume Number | 142 |
| Language | English |
| Publisher | Elsevier BV |
| Publisher Date | 2016-11-01 |
| Access Restriction | Open |
| Subject Keyword | Journal: NeuroImage Arterial Spin Labeling Background Suppression Cmro(2) Quantification |
| Content Type | Text |
| Resource Type | Article |
| Subject | Neurology Cognitive Neuroscience |
