Question

Question Posted 06/11/14:
Dear the officer:

Sorry to bother you.

For the PET subject: 052_S_0989/ADNI_Brain_PET__Raw_FDG/2011-01-05_10_36_42.0/I213447,
There are totally 6 scans:
ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144015496_52_S97959_I213447.nii ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144043949_372_S97959_I213447.nii
ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144015886_516_S97959_I213447.nii ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144050214_150_S97959_I213447.nii
ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144025933_263_S97959_I213447.nii ADNI_052_S_0989_PT_ADNI_Brain_PET__Raw_FDG_br_raw_20110121144137230_273_S97959_I213447.nii

We are wondering how could we find the order of these 6 files. It is determined by 52, 150, 263, 273, 372, 516?
Or Could you tell me the meaning for "20110121144015496_52"? I know "20110121" is the 2011-01-21.

Thanks so much!

best,
li

Response posted 06/18/14 by Bob Koeppe:
The original images are in DICOM, and the scan times of each of the six frames are in the DICOM headers. I am not an expert in Nifti format (.nii), but I would assume that the conversion to nifti maintains the time offsets for each of the six frames some where in the nifti header.