2019/08/08 by Erin K. Englund, Erin K Englund, María A. Fernández‐Seara +11
Medicine · Neuroscience · Physics and Astronomy · #Advanced MRI Techniques and Applications #Atomic and Subatomic Physics Research #Functional Brain Connectivity Studies
paper · pdf · doi:10.1177/0271678x19867276
openalex publication_date 2019/08/08 · openalex created_date 2019/08/22 · openalex updated_date 2026/07/30
Functional MRI (fMRI) can identify active foci in response to stimuli through BOLD signal fluctuations, which represent a complex interplay between blood flow and cerebral metabolic rate of oxygen (CMRO 2 ) changes. Calibrated fMRI can disentangle the underlying contributions, allowing quantification of the CMRO 2 response. Here, whole-brain venous oxygen saturation ( Y v ) was computed alongside ASL-measured CBF and BOLD-weighted data to derive the calibration constant, M, using the proposed Y v -based calibration. Data were collected from 10 subjects at 3T with a three-part interleaved sequence comprising background-suppressed 3D-pCASL, 2D BOLD-weighted, and single-slice dual-echo GRE (to measure Y v via susceptometry-based oximetry) acquisitions while subjects breathed normocapnic/normoxic, hyperoxic, and hypercapnic gases, and during a motor task. M was computed via Y v -based calibration from both hypercapnia and hyperoxia stimulus data, and results were compared to conventional hypercapnia or hyperoxia calibration methods. Mean M in gray matter did not significantly differ between calibration methods, ranging from 8.5 ± 2.8% (conventional hyperoxia calibration) to 11.7 ± 4.5% (Y v -based calibration in response to hyperoxia), with hypercapnia-based M values between ( p = 0.56). Relative CMRO 2 changes from finger tapping were computed from each M map. CMRO 2 increased by ∼20% in the motor cortex, and good agreement was observed between the conventional and proposed calibration methods.