Freesurfer May 2005

freesurfer@nmr.mgh.harvard.edu

26 participants
53 discussions

RE: [Freesurfer] WMFilll and talairach coordinates
by Fornito, Alexander 17 May '05

17 May '05

Hi, Just to toss my hat into the ring, can I ask why the transform is kept. Is it used later on? I've also been having trouble with the MNI tools, and was thinking of using FLIRT or AIR to align the images first. What is th point of having the .xfm? Thanks, Alex -----Original Message----- From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Wed 5/18/2005 6:00 AM To: peggy christidis Cc: freesurfer(a)nmr.mgh.harvard.edu Subject: Re: [Freesurfer] WMFilll and talairach coordinates Hi Peggy, we don't apply the transform, just keep it around, so blurring isn't a problem. I don't know if AFNI knows how to write out .xfm files (the mni transform format), but that would be the best solution. Bruce On Tue, 17 May 2005, peggy christidis wrote: > Hello, > > I'm having a bit of trouble with the "Create Surface" step in FreeSurfer. I > have a single mprage scan that creates a decent first pass surface, but > there's still some brainstem and cerebellum attached to it. I followed the > troubleshooting guidelines in the FreeSurfer manual regarding Failure of > Automatic Cutting Planes. I went to Expert Preferences --> WMFill, and > inputed the appropriate coordinates to separate the brainstem and cerebellum. > The coordinates I used were not in Talairach space, but I assumed this was > okay because the manual says to use original coordinates if you don't have > Talairach coordinates. However, when I re-ran "Create Surface", nothing > happened (i.e., filled volume and surface both still show the > pons/cerebellum/brainstem attached). I read through the FreeSurfer mailing > list archives and read that Talairach coordinates are indeed needed. > > Here's my question: The volume I'm using shows a head that's slightly tilted > about 10 degrees to the left, so I should probably do the Taliarach > transformation anyway. However, I don't have the mni_tools installed on my > computer (I had major installation problems with them). Anyway, could I do a > taliarach transformation outside of Freesurfer (like in AFNI) and then > tranfer that talairached volume to FreeSurfer? My concern is that the > transformation will blur the volume, making segmentation difficult. What > should I do? > > Thanks, > Peggy > _______________________________________________ > Freesurfer mailing list > Freesurfer(a)nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > _______________________________________________ Freesurfer mailing list Freesurfer(a)nmr.mgh.harvard.edu https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer

2 1

RE: [Freesurfer] Segmentation error
by Fornito, Alexander 17 May '05

17 May '05

Great. Thanks!! -----Original Message----- From: florent segonne [mailto:fsegonne@csail.mit.edu] Sent: Wed 5/18/2005 1:22 AM To: Fornito, Alexander Cc: freesurfer(a)nmr.mgh.harvard.edu Subject: Re: [Freesurfer] Segmentation error Hello Alex, This warning message appears during the watershed segmentation process. The final brain shape is compared to a statistical atlas and the correctness of the segmentation (of the shape) is evaluated. It turns out that the validation is often too restrictive and often generates a useless warning message. As a consequence, you should most often ignore this message. If the skull stripping appears to be incorrect, this message might then become of interest. In any case, we'll shortly fix this. Best, Florent

1 0

WMFilll and talairach coordinates
by peggy christidis 17 May '05

17 May '05

Hello, I'm having a bit of trouble with the "Create Surface" step in FreeSurfer. I have a single mprage scan that creates a decent first pass surface, but there's still some brainstem and cerebellum attached to it. I followed the troubleshooting guidelines in the FreeSurfer manual regarding Failure of Automatic Cutting Planes. I went to Expert Preferences --> WMFill, and inputed the appropriate coordinates to separate the brainstem and cerebellum. The coordinates I used were not in Talairach space, but I assumed this was okay because the manual says to use original coordinates if you don't have Talairach coordinates. However, when I re-ran "Create Surface", nothing happened (i.e., filled volume and surface both still show the pons/cerebellum/brainstem attached). I read through the FreeSurfer mailing list archives and read that Talairach coordinates are indeed needed. Here's my question: The volume I'm using shows a head that's slightly tilted about 10 degrees to the left, so I should probably do the Taliarach transformation anyway. However, I don't have the mni_tools installed on my computer (I had major installation problems with them). Anyway, could I do a taliarach transformation outside of Freesurfer (like in AFNI) and then tranfer that talairached volume to FreeSurfer? My concern is that the transformation will blur the volume, making segmentation difficult. What should I do? Thanks, Peggy

2 1

Segmentation error
by Fornito, Alexander 17 May '05

17 May '05

Hi, When running segment_subject, I get a meesage saying THE SEGMENTATION IS PROBABLY NOT CORRECT at the validation stage. Any hints as to what might be causing this and how to fix? Thanks, Alex

2 1

FW: [Freesurfer] Appropriate post-editing processing
by Fornito, Alexander 16 May '05

16 May '05

-----Original Message----- From: Fornito, Alexander Sent: Tue 5/17/2005 12:51 PM To: Bruce Fischl Cc: Subject: RE: [Freesurfer] Appropriate post-editing processing For lh.white and lh.pial it is: euler # = v-e+f = 2g-2: 0 - 0 + 0 = 0 --> 1 holes F =2V-4: 0 != 0-4 (-4) 2E=3F: 0 = 0 (0) total defect index = 2 As far as I'm aware my version of Freesurfer is up to date (we downloaded within the past month). You've confused me abit - I thought the point of manual editing was to get a topologically correct surface? Thanks for your help, Alex -----Original Message----- From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Tue 5/17/2005 11:58 AM To: Fornito, Alexander Cc: freesurfer(a)nmr.mgh.harvard.edu Subject: Re: [Freesurfer] Appropriate post-editing processing what is the euler number? It should be 2 in all cases - you shouldn't have to edit to get a topologically correct surface. In some cases it was 1 or 0, but Florent fixed those problems a while ago, so if you have an up-to-date version of mris_fix_topology it should be 2. cheers, Bruce On Tue, 17 May 2005, Fornito, Alexander wrote: > Hi all, > I've created the final surface on one of my images and noticed that mris_euler_number has detected defects. I've gone back to edit what i think is the problem and was wandering if I need to go through the whol process again (create surface -> Fix topology correction -> Create final surface), or if I can just run create final surface again. > Thanks, > Alex > > _______________________________________________ > Freesurfer mailing list > Freesurfer(a)nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >

1 0

Appropriate post-editing processing
by Fornito, Alexander 16 May '05

16 May '05

Hi all, I've created the final surface on one of my images and noticed that mris_euler_number has detected defects. I've gone back to edit what i think is the problem and was wandering if I need to go through the whol process again (create surface -> Fix topology correction -> Create final surface), or if I can just run create final surface again. Thanks, Alex

2 1

RE: [Freesurfer] create_subject usage
by Fornito, Alexander 16 May '05

16 May '05

Sorry, was thinking of someting else. That helps - thanks! -----Original Message----- From: Bruce Fischl [mailto:fischl@nmr.mgh.harvard.edu] Sent: Mon 5/16/2005 9:40 PM To: Fornito, Alexander Cc: freesurfer(a)nmr.mgh.harvard.edu Subject: Re: [Freesurfer] create_subject usage p.s. I don't know what create_subject is On Mon, 16 May 2005, Fornito, Alexander wrote: > Hi, > Does anyone know if its possible to use options with create_subject and inflate_subject in the command line (eg., one hemisphere only). I've been unable to bring up the usage (e.g, -u or -help). > Thanks, > Alex > > _______________________________________________ > Freesurfer mailing list > Freesurfer(a)nmr.mgh.harvard.edu > https://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer >

1 0

create_subject usage
by Fornito, Alexander 16 May '05

16 May '05

Hi, Does anyone know if its possible to use options with create_subject and inflate_subject in the command line (eg., one hemisphere only). I've been unable to bring up the usage (e.g, -u or -help). Thanks, Alex

3 3

flattening with "folded" brain cuts
by Joongnam Yang 16 May '05

16 May '05

Hi all, Freesurfer allows occipital cuts of "inflated" brain to be flattened. Is it possible to flatten occipital cuts of "folded" brain? Nam.

1 0

check_subject
by Wan Park 12 May '05

12 May '05

when i put check_subject 14456, i receive this message: [ogden:freesurfer_package/freesurfer/subjects] wpark% check_subject 14456 CHECKING SUBJECT 14456 WARN: lh.rh.sphere.reg is empty/missing [ogden:freesurfer_package/freesurfer/subjects] wpark% is there any problem? wan

2 1

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

Freesurfer May 2005