Figure 2.

Fractional signal changes (ΔS/S) observed with spin-echo fMRI data in the cervical spinal cord as a function of echo time at 1.5 tesla. Data are average values from 15 healthy volunteers. Average values for the 1^st and 2^nd measures obtained with echo time = 11 msec are plotted separately. The solid line demonstrates the result of fitting with a non-linear model, whereas the dashed line demonstrates a linear fit to data with echo time >33 msec only. Error bars indicate the standard error of the mean.