Cox R W, Jesmanowicz A, Hyde J S
Biophysics Research Institute, Medical College of Wisconsin, Milwaukee 53226-0509, USA.
Magn Reson Med. 1995 Feb;33(2):230-6. doi: 10.1002/mrm.1910330213.
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.
提出了一种适用于功能磁共振成像（FMRI）计算的递归算法。图像时间序列与参考时间序列的相关系数，在去除均值和任何线性趋势后，每个体素、每张图像可通过22次运算计算得出；存储开销为每个体素四个数字。提出了FMRI信号的统计模型，并据此得出相关系数的阈值。展示了首次实时功能神经成像实验（3特斯拉）中的选定图像。使用配备14位模数转换器的50兆赫兹工作站，每个回波平面图像在射频脉冲后的500毫秒内完成采集、重建、相关计算、阈值处理，并以伪彩色显示（突出显示大脑中的活跃区域）。
