The FBIRN’s imaging calibration methods currently include:
- Use of an agar phantom to confirm imaging quality;
- Determining smoothness of an imaging dataset and correcting for differences across data sources;
- Inclusion of a non-cognitive measure to calibrate the BOLD signal for each subject. This has included a finger-tapping task, voluntary breath holding, and currently under development, Arterial Spin Labeling (ASL).
Under the FBIRN QC protocol, the FBIRN agar phantom is scanned using the same FMRI parameters we are using in our present study. The data collected on the agar phantom is processed using the FBIRN automated QC processing tools. Acceptable values for percent noise fluctuation, image smoothness, and SFNR were established based on values achieved by identical scans that were known to be functioning well.
The appropriate collection, analysis, and use of the breathhold and ASL data to reduce unwanted variation are a current area of research in the multi-site FBIRN imaging efforts.
More information about these methods can be found at the FBIRN Best Practices FAQ.
