FBIRN recommends careful scanner measurements prior to attempting to combine data across sites or MRI scanners. These can be used as Quality Assurance (QA) methods to include a site’s data in a study.
These QA scans are routinely performed and used to verify and measure the scanner stability during a typical fMRI scanning sequence. The scans are performed on a 17cm spherical phantom filled with an agar gel. The scans consist of 200 separate image volumes captured over roughly a 10-minute interval. The drift, fluctuations, signal to noise ratios, and other measures indicate the scanner’s background noise relative to its stability.
- The instructions and analysis methods are part of the BXH/XCEDE QA tools and can be downloaded here.
- Original versions, for archive purposes only, are available here.
- Examples of QA measures from various scanners are here: Download will be available soon. Please check again.
Figure: Images of time series maps produced by qa_calc_fbirn.m. (A) average, (B) standard deviation, (C) noise average, (D) SFNR.
