that looks right. how different are the values?
On 04/05/2017 10:58 AM, Gullickson, James wrote: > Hello all, > > I want to calculate a Ventricle-to-Brain ratio (VBR) as a measure of > parenchymal atrophy using Freesurfer version 5.3.0. I have tried to go > about this using the aseg.stats output (using asegstats2table), but am > running into inconsistencies. > > The basic calculation for VBR is: > > (Total Ventricular Volume/Total Brain Volume) * 100 > > i.e. Bigler, E. D. (2013). Traumatic brain injury, neuroimaging, and > neurodegeneration. /Frontiers in human neuroscience/, /7/, 395. > > > What is the best way to get Total Ventricular Volume (TVV) and Total > Brain Volume (TBV) for this calculation? I have tried several ways, > which lead to different values: > > TVV = left lateral ventricle + left inf lateral ventricle + right > lateral ventricle + right inf lateral ventricle + 3rd ventricle + 4th > ventricle + 5th ventricle + choroid plexus > > which gives me a different result than > > TVV = BrainSegVol - BrainSegVolNotVent > > > and for TBV > > TBV = TotalGrayVol + CorticalWhiteMatterVol > > which differs from > > TBV = BrainSegVolNotVent > > > Thank you for your help, > > James Gullickson > > > > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer -- Douglas N. Greve, Ph.D. MGH-NMR Center gr...@nmr.mgh.harvard.edu Phone Number: 617-724-2358 Fax: 617-726-7422 Bugs: surfer.nmr.mgh.harvard.edu/fswiki/BugReporting FileDrop: https://gate.nmr.mgh.harvard.edu/filedrop2 www.nmr.mgh.harvard.edu/facility/filedrop/index.html Outgoing: ftp://surfer.nmr.mgh.harvard.edu/transfer/outgoing/flat/greve/ _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer The information in this e-mail is intended only for the person to whom it is addressed. If you believe this e-mail was sent to you in error and the e-mail contains patient information, please contact the Partners Compliance HelpLine at http://www.partners.org/complianceline . If the e-mail was sent to you in error but does not contain patient information, please contact the sender and properly dispose of the e-mail.
