Ok.  So then if ventricular volume is already excluded, the brain
parenchymal volume should be:

Total GM + total cortical WM +cerebellar GM + cerebellar WM + brain stem -
CSF?

Cheryl 


On 11-12-15 2:58 PM, "Douglas N Greve" <[email protected]> wrote:

> Yes.
> 
> Alexopoulos, Dimitrios wrote:
>> Just for clarification, the standard output value in the aseg.stats for total
>> cortical WM
>> is detremined with 'mris_wm_volume' which subtracts out the volume of non-wm
>> voxels based on the
>> aseg, correct?
>> 
>> Jim
>> 
>> ________________________________________
>> From: [email protected]
>> [[email protected]] on behalf of Douglas N Greve
>> [[email protected]]
>> Sent: Thursday, December 15, 2011 3:02 PM
>> To: Cheryl McCreary
>> Cc: [email protected]
>> Subject: Re: [Freesurfer] Estimate Brain Volume Fraction
>> 
>> total cortical WM should not include the ventricles. If the lateral
>> ventricles are not segmented properly, then they would be included, but
>> this would be an error. Otherwise, I think your equation is correct.
>> doug
>> 
>> Cheryl McCreary wrote:
>>   
>>> Hi Doug,
>>> 
>>> Thanks for the quick reply.  I will re-run the mri_segstats as below to get
>>> the BrainSegNotVent volumes for consistency with the previous version.
>>> 
>>> Just for my own understanding using the default output aseg.stats from
>>> recon-all, could whole brain parenchymal volume be calculated as  [(total
>>> GM, total cortical WM, cerebellar GM, cerebellar WM + brain-stem)-2*(left
>>> lateral ventricle + left Inf Lat Vent + right lateral ventricle+ right inf
>>> lat vent) - CSF)]? I'm assuming that since both the white matter and pial
>>> surfaces include the lateral ventricle, the lateral ventricular volume needs
>>> to be subtracted, while the 3rd and 4th ventricles are not included in the
>>> surfaces and therefore would not need to be subtracted?
>>> 
>>> Kind regards,
>>> Cheryl
>>> 
>>> 
>>> On 11-12-14 12:45 PM, "Douglas N Greve" <[email protected]> wrote:
>>> 
>>> 
>>>     
>>>> Hi Cheryl,
>>>> You can regenerate the asseg.stats file with BrianVolNotVent with:
>>>> 
>>>> cd $SUBJECTS_DIR/yoursubject
>>>>  mri_segstats --subject yoursubject --seg mri/aseg.mgz --sum
>>>> stats/aseg.stats --pv mri/norm.mgz --empty --excludeid 0 --excl-ctxgmwm
>>>> --supratent --subcortgray --in mri/norm.mgz --in-intensity-name norm
>>>> --in-intensity-units MR --etiv --surf-wm-vol --surf-ctx-vol --totalgray
>>>> --ctab /usr/local/freesurfer/dev/ASegStatsLUT.txt  --brain-vol-from-seg
>>>> 
>>>> This is the same command that generated the existing aseg.stats file
>>>> with "--brain-vol-from-seg" added.
>>>> 
>>>> doug
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> Cheryl McCreary wrote:
>>>> 
>>>>       
>>>>> Hi Freesurfer experts,
>>>>> 
>>>>> I would like to determine brain parenchymal fraction (ie brain tissue
>>>>> volume/estimated ICV) as an estimate of global atrophy.  In previous
>>>>> versions of FS, I used the BrianVolNotVent/ICV.  Is this correct?
>>>>> 
>>>>> I am now using freesurfer version 5.0.0 and BrainVolNotVent is not longer
>>>>> available.
>>>>> 
>>>>> My understanding is that the total gray matter and total cortical white
>>>>> matter volumes are determined from the pial and white surfaces (thickness
>>>>> *surface area).  Do these volumes include or exclude the ventricular
>>>>> volumes? Can the total brain volume be calculated as the sum of the total
>>>>> GM, total cortical WM, brain stem, cerebellar GM and WM minus the CSF.  Or
>>>>> do the volumes of the ventricles need to be subtracted as well?
>>>>> 
>>>>> Thanks for your help.
>>>>> 
>>>>> Cheryl
>>>>> 
>>>>> 
>>>>>         
>>>     
>> 
>> --
>> Douglas N. Greve, Ph.D.
>> MGH-NMR Center
>> [email protected]
>> Phone Number: 617-724-2358
>> Fax: 617-726-7422
>> 
>> Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting
>> FileDrop: www.nmr.mgh.harvard.edu/facility/filedrop/index.html
>> 
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-- 
Cheryl McCreary
Research Assistant Professor
Seaman Family MR Research Centre
Foothills Medical Centre
1403 29th Street NW
Calgary, AB
T2N 2T9
Phone: (403) 944-8781
FAX: (403) 270-7907


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