Real-time functional magnetic resonance imaging.
A recursive algorithm suitable for functional magnetic resonance imaging (FMRI) calculations is presented. The correlation coefficient of a time course of images with a reference time series, with the mean and any linear trend projected out, may be computed with 22 operations per voxel, per image; the storage overhead is four numbers per voxel. A statistical model for the FMRI signal is presented, and thresholds for the correlation coefficient are derived from it. Selected images from the first real-time functional neuroimaging experiment (at 3 Tesla) are presented. Using a 50-MHz workstation equipped with a 14-bit analog-to-digital converter, each echo planar image was acquired, reconstructed, correlated, thresholded, and displayed in pseudocolor (highlighting active regions in the brain) within 500 ms of the RF pulse.
Cox
R W
RW
Biophysics Research Institute, Medical College of Wisconsin, Milwaukee 53226-0509, USA.
Jesmanowicz
A
A
Hyde
J S
JS
D000465:Algorithms; D000703:Analog-Digital Conversion; D001921:Brain / Q000033:anatomy & histology / Q000502:physiology; D003116:Color; D003199:Computer Systems; D003626:Data Display; D017352:Echo-Planar Imaging / Q000379:methods / Q000706:statistics & numerical data; D005385:Fingers / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods* / Q000706:statistics & numerical data; D016013:Likelihood Functions; D008279:Magnetic Resonance Imaging / Q000379:methods* / Q000706:statistics & numerical data; D015233:Models, Statistical; D009048:Motor Skills / Q000502:physiology; D013997:Time Factors