Michelle Quigley

Test-retest precision of functional magnetic resonance imaging processed with independent component analysis

This study was designed to compare the test-retest precision of functional magnetic resonance imaging (fMRI) data processed with independent component analysis (ICA) and the same data analyzed with a conventional model-dependent method (Students-t mapping). Volunteers underwent two or three iterations of visual and auditory stimuli, while data were collected for fMRI scans. The scan data were separately processed with ICA and with Students-t mapping (STM). As a measure of test-retest precision, concurrence ratios were calculated for each subject and each task as the number of voxels that were activated by two iterations of a task divided by the average number of voxels activated in each repetition. In 28 test-retest comparisons, the average concurrence ratio was 0.69±0.10 for ICA and 0.65±0.13 for the conventional method, a statistically insignificant difference. In fMR image data of block stimulus paradigms, ICA had similar test-retest precision to a conventional model-dependent method.