No, I don't need signed values necessarily. So just to double-check then, higher mean curvature for averaged across a gyral ROI label would mean the gyrus has a more steeply peaked appearance, whereas high values for a sulcal label would, conversely, mean the sulcus resembles a shraply bended valley?
Alex Fornito M.Psych/PhD (clin. neuro.) candidate Melbourne Neuropsychiatry Centre and Department of Psychology National Neuroscience Facility The University of Melbourne Levels 2 & 3, Alan Gilbert Building 161 Barry St Carlton South Vic 3053 Australia Ph: +61 3 8344 1624 Fax: +61 3 9348 0469 email: [EMAIL PROTECTED] -----Original Message----- From: Bruce Fischl [mailto:[EMAIL PROTECTED] Sent: Fri 5/26/2006 10:21 PM To: Fornito, Alexander Cc: freesurfer@nmr.mgh.harvard.edu Subject: RE: [Freesurfer] ROI Curvature p.s. sorry, the mean and Gaussian curvatures displayed in mris_anatomical_stats are absolute value. I forgot this, sorry. The integrate Gaussian curvature is actually a topological invariant, so doesn't tell you much about the surface. Do you really need signed mean curvaature averaged over a region? If so, you could specify -T curv, so that the "thickness" is actually the curvature, and it will give you the mean and std. Bruce On Fri, 26 May 2006, Fornito, Alexander wrote: > Yup. That looks fine. > > > Alex Fornito > M.Psych/PhD (clin. neuro.) candidate > Melbourne Neuropsychiatry Centre and Department of Psychology > National Neuroscience Facility > The University of Melbourne > Levels 2 & 3, Alan Gilbert Building > 161 Barry St > Carlton South Vic 3053 Australia > Ph: +61 3 8344 1624 > Fax: +61 3 9348 0469 > email: [EMAIL PROTECTED] > > > > -----Original Message----- > From: Bruce Fischl [mailto:[EMAIL PROTECTED] > Sent: Fri 5/26/2006 9:44 PM > To: Fornito, Alexander > Cc: freesurfer@nmr.mgh.harvard.edu > Subject: RE: [Freesurfer] ROI Curvature > > when you overlay the ?h.curv file on the inflated surface does it look > correct? Are there both red and green regions? > On Fri, 26 May 2006, Fornito, > Alexander wrote: > >> I mainly interested in the mean curvature. >> >> This is output for a gyral ROI: >> >> % 1001365: <wm vol> <surf area> <gray vol> <thick mean> <thick var> <integ >> rect. mean curv> <integ rect. Gauss curv> <fold index> <intr curv ind> >> 647773 395 1297 3.145 0.780 0.151 0.027 4.123 0.572 >> >> This is for a sulcal ROI; >> >> % 1001365: <wm vol> <surf area> <gray vol> <thick mean> <thick var> <integ >> rect. mean curv> <integ rect. Gauss curv> <fold index> <intr curv ind> >> 647773 563 1693 2.992 0.567 0.121 0.068 48.616 4.783 >> >> Cheers, >> Alex >> >> Alex Fornito >> M.Psych/PhD (clin. neuro.) candidate >> Melbourne Neuropsychiatry Centre and Department of Psychology >> National Neuroscience Facility >> The University of Melbourne >> Levels 2 & 3, Alan Gilbert Building >> 161 Barry St >> Carlton South Vic 3053 Australia >> Ph: +61 3 8344 1624 >> Fax: +61 3 9348 0469 >> email: [EMAIL PROTECTED] >> >> >> >> -----Original Message----- >> From: Bruce Fischl [mailto:[EMAIL PROTECTED] >> Sent: Fri 5/26/2006 8:32 AM >> To: Fornito, Alexander >> Cc: freesurfer@nmr.mgh.harvard.edu >> Subject: RE: [Freesurfer] ROI Curvature >> >> which curvature values. Can you send the output? >> >> On Fri, 26 May 2006, Fornito, Alexander wrote: >> >>> Sorry, got it wrong way around. >>> Either way, when I run mris_anatomical_stats on labels that I have created, >>> I tend to get positive values for mean curvature for labels of both gyral >>> crowns or sulcal fundi. Are the curvature values provided by >>> mris_anatomical_stats unsigned? >>> >>> Alex Fornito >>> M.Psych/PhD (clin. neuro.) candidate >>> Melbourne Neuropsychiatry Centre and Department of Psychology >>> National Neuroscience Facility >>> The University of Melbourne >>> Levels 2 & 3, Alan Gilbert Building >>> 161 Barry St >>> Carlton South Vic 3053 Australia >>> Ph: +61 3 8344 1624 >>> Fax: +61 3 9348 0469 >>> email: [EMAIL PROTECTED] >>> >>> >>> >>> -----Original Message----- >>> From: Bruce Fischl [mailto:[EMAIL PROTECTED] >>> Sent: Thu 5/25/2006 9:09 PM >>> To: Fornito, Alexander >>> Cc: freesurfer@nmr.mgh.harvard.edu >>> Subject: Re: [Freesurfer] ROI Curvature >>> >>> Hi Alex, >>> >>> the gyri will should have negative mean curvature and the sulci positive. >>> You can overlay the ?h.curv map to check. >>> >>> cheers, >>> Bruce >>> On Thu, 25 May 2006, Fornito, >>> Alexander wrote: >>> >>>> Hi, >>>> I have some labels that I've drawn, which correspond to the gyral crown >>>> and sulcal fundus of a given ROI. From what I understand, mean curvature >>>> provides an index of the convexity/concavity of the region. I would >>>> therefore have expected high positive values in the gyral ROI to represent >>>> a steeper peak in the curvature of the crown, with values closed to zero >>>> representing a more flattened gyrus. Converseley, I would have thought low >>>> negative values for the fundus ROI would represent a steeper peak in the >>>> opposite direction, with values closer to zero again reflecting flattened >>>> curvature. >>>> In reality, the values I get for both sulcal and gyral labels (using >>>> mris_anatomical_stats) tend to be both positive. >>>> Hoping someone could tell me what I'm missing? >>>> >>>> Thanks in advance, >>>> Alex >>>> >>>> >>>> >>>> >>>> Alex Fornito >>>> M.Psych/PhD (clin. neuro.) candidate >>>> Melbourne Neuropsychiatry Centre and Department of Psychology >>>> National Neuroscience Facility >>>> The University of Melbourne >>>> Levels 2 & 3, Alan Gilbert Building >>>> 161 Barry St >>>> Carlton South Vic 3053 Australia >>>> Ph: +61 3 8344 1624 >>>> Fax: +61 3 9348 0469 >>>> email: [EMAIL PROTECTED] >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Freesurfer mailing list >>>> Freesurfer@nmr.mgh.harvard.edu >>>> https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >>>> >>>> >>>> >>> >>> >>> >>> >> >> >> >> > > > > _______________________________________________ Freesurfer mailing list Freesurfer@nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer
