My experience with eTIV is that it's great with a perfect Talairach
transform but otherwise is less accurate than other measures. Manually
fixing the transforms and reprocessing as necessary will result in great
eTIVs but requires quite a bit of manual work.
What we do instead is just use the brainmask volume (but our data are MRIs
of non-demented older adults so there's not typically extensive atrophy).
We've found that brainmask has a Dice Similarity Coefficient of 0.95 and an
ICC of 0.92 with manually traced intracranial masks (inferior termination
on a straight line between the lowest portion of the clivus and occipital
bone). eTIV had an ICC of 0.67 with our manual masks (but we didn't fix the
transformations).
Jared
____
Jared Tanner, Ph.D.
Research Assistant Professor
Clinical and Health Psychology
University of Florida
> ---------- Forwarded message ----------
> From: "Harms, Michael" <mharms(a)wustl.edu>
> To: "freesurfer(a)nmr.mgh.harvard.edu" <freesurfer(a)nmr.mgh.harvard.edu>
> Cc:
> Date: Sun, 21 Feb 2016 18:10:12 +0000
> Subject: Re: [Freesurfer] eTIV question
>
> Hi,
> Why not use a measurement of brain size rather than “eTIV”?
>
> cheers,
> -MH
>
> --
> Michael Harms, Ph.D.
>
> -----------------------------------------------------------
> Conte Center for the Neuroscience of Mental Disorders
> Washington University School of Medicine
> Department of Psychiatry, Box 8134
> 660 South Euclid Ave.Tel: 314-747-6173
> St. Louis, MO 63110Email: mharms(a)wustl.edu
>
>