FIG. 3.

An example comparison of the original Gaussian fit (green) and the globally estimated empirical ACF values (black) from a single subject, which have large differences (importantly, in the tail drop-off above r ∼ 8 mm). The proposed mixed model (red) after fitting parameters as described in Eq. (3) provides a much better fit of the data in this case (and in all cases in the data sets used herein). This plot is automatically generated in program 3dFWHMx.