Question Posted 04/25/16:
Dear ADNI experts,
I am looking to normalise regional brain volumes by intracranial volumes. I am having difficulty locating the necessary values. Having started preliminary analyses with data values from 'adnimerge', to my knowledge these volumes do not match those found in other 'UCS' data files on the ADNI data site (eg. 'ucsfsntvol' or 'ucsdvol'). I wanted to ensure that I am using values correctly and consistently. Is it the case that the values found in the adnimerge file are normalised?
Thank you for your assistance.
Response posted 04/26/16 by D. Harvey:
ADNIMERGE includes data from the UCSF FreeSurfer files. There is a variable in the ADNIMERGE file called ICV (for ICV), which corresponds to ST10CV in the FreeSurfer files. Hippocampus in the ADNIMERGE file, for example, is ST29SV+ST88SV (variables in the FreeSurfer files). You can check the data dictionaries for the specific FreeSurfer files for the variables corresponding to specific regions.