I've looked around and it seems that there should be a parameter like "days from entry" which should allow me to calculate the time interval between non-simultaneously acquired (FDG) PET-rsfMRI data, even though the exact dates of acquisition are not available. (Otherwise, can I assume that all (FDG) PET-rsfMRI data were acquired on the same day or were simultaneous?)

Does anyone know how I could obtain the "days from entry" information for each subject's data?

-Gin