Hello,

By far the most common reason I have to throw out data due to head motion is head-nodding. I recall from some AFNI course long ago some mention from an instructor (maybe it was Bob) that AFNI motion correction might be improved if investigators adopted sagittal slice aquisition and used some AFNI plug-in program that was specifically intended for two-dimensional motion correction, and could accomodate and re-align more severe motion if that motion was IN-PLANE. Then, run 3dvolreg on the sag-corrected 3d+time dataset.

Was I hallucinating? If not, could someone expand on what this idea is and how to implement it. Use 2dImReg? By reading the 2dImReg manual, it doesn't seem like the original slice acqusition orientation matters.

Is there anything I can do for data already collected axially, where application of 3dvolreg still yields an output dataset that looks jerky by cineloop on the sagittal view?

Jim B