Hi Mark (or whoever else might know), Could you help me understand the various options pertaining to sinc interpolation in MCFLIRT? Looking at the usage in version 4.1.6, it seems that there are two different options, "-sinc_final" and setting the "-stages" argument to 4. Running MCFLIRT with a permutation of these flags (in other words, calling it three times with the same input and reference volume but using both, or either one in isolation) seems to produce three different images (according to a diff between them). But, what is actually going on differently in the algorithm? Unfortunately, the online MCFLIRT user guide seems not to have any information on the -sinc_final option. Thanks! Cheers, Michael