afni.nimh.nih.gov

3dUndump might be what you want. It takes values from a text file and creates a dataset. You can set the dimensions. For multiple time points you can use it several times and glue the results together with 3dbucket or 3dTcat.

If the data is a binary file, you could use to3D if you know the format well.

If you have made the data in Matlab, you could potentially use AFNI's Matlab library.