Freesurfer February 2019

freesurfer@nmr.mgh.harvard.edu

114 participants
196 discussions

Hypointensities in Freesurfer
by Miguel Ángel Rivas Fernández 11 Feb '19

11 Feb '19

External Email - Use Caution Hi Freesurfer devs, I saw that Freesurfer export measures of hypointensities. I was wondering if it´s possible to know where are located this brain lesions using as reference some neuroanatomical atlas. Best, -- *Miguel Ángel Rivas Fernández*

2 3

reporting fsl PALM results
by C.P.E. Rollins 11 Feb '19

11 Feb '19

External Email - Use Caution Dear Freesurfer Developers, I'm using PALM to run permutation analyses to correct for multiple comparisons on Freesurfer cortical thickness and LGI data. fspalm from a command like "mri_glmfit-sim --glmdir lh.lgi.glmdir --perm 1000 2 pos --cwp .05 --2spaces" produces output files including *.cluster.mgh - map of signifcant clusters, *.cluster.summary - text file of of cluster table (incl. sizes, cluster annotation, MNI coordinates, and significance), and *.y.ocn.dat – text file containing LGI or cortical thickness values for each subject from significant clusters. I was wondering if PALM produces similar output? From my understanding the *clustere_tstat_fwep.mgz file from PALM would be equivalent to the *.cluster.mgh from fspalm, but is there any way to get a text file of the cluster table or of the LGI/CT values for each subject from significant clusters?I would like to report significant clusters (ie. coordinates or parcellation, cluster size, pvalue) in a table and also to extract the average lgi/thickness from significant clusters for each subject. Thanks very much Colleen

2 3

"CorticalWhiteMatterVol" ?
by Gonzalo Rojas Costa 11 Feb '19

11 Feb '19

External Email - Use Caution Hi: What is the meaning of the "CorticalWhiteMatterVol" measure? Sincerely, Gonzalo Rojas Costa

2 1

PETSurfer: "mri_gtmpvc --psf 0 --no-tfe" voxel-wise output
by Matthieu Vanhoutte 11 Feb '19

11 Feb '19

External Email - Use Caution Dear Douglas, Before using "mri_gtmpvc --psf 0 --no-tfe -- rbv" according your advice to obtain voxel-wise output rescaled without PVC correction, I have done sequentially the different steps to obtain this output. However, when comparing voxel-wise rescaled output (rbv.nii.gz) between the two methods, final values at each voxel are not the same… To obtain first rescaled voxel-wise output I have used sequentially these steps: 1. Concatenate transforms from PET space to gtmseg.mgz 2. Register native PET into gtmseg space (trilin. interpolation) 3. Compute mean PET inside reference regions (with regions masks from gtmseg.mgz) 4. Compute intensity normalized PET images in gtmseg space Doesn’t the "mri_gtmpvc --psf 0 --no-tfe -- rdv" command use these same steps ? Best, Matthieu

2 1

hippocampus subfield division
by Yixin Ma 11 Feb '19

11 Feb '19

External Email - Use Caution Hi Freesurfer experts, I'm writing to ask about the hippocampus subfield division again. Last time, I gave you an example of the subject that I failed to run the hippocampal subfield division, and you told me that you were able to run the hippocampus subfield on your laptop. I was using the older command of recon-all -all -s bert -hippocampal-subfields-T1. Should I try to use the newer version: segmentHA_T1.sh bert [SUBJECTS_DIR]. Is that possible FreeSurfer upgrading is the reason that I failed to run a subject on my server recently (but I was able to run it before). Also, can I ask where can I find the file of segmentHA_T1.sh? Thanks for your help. Cheers, Yixin

2 1

Runtime of Freesurfer on Linux VM on Google Cloud Platform
by Yi-Fang Chuang 10 Feb '19

10 Feb '19

External Email - Use Caution Dear Freesurfer developers and users, Has anyone had experience running Freesurfer on Linux VM on Google Cloud Platform? I have a question about runtime of recon-all -all. The specs of VM on GCP as follows, Linux CentOS 6, 16 CPU(Intel(R) Xeon(R) @ 2.50GHz) with 60 G memory I installed Freesurfer v 6.0.0 and run recon-all -all -parallel -openmp num No matter what number I put (6,8,12,16 after openmp), the recon-all runtime of a single subject ranges 6-7 hours. It's just disappointing to compare to my own desktop. My own Desktop is Mac Pro (3.7 GHz quad-core intel xeon E5, 16G memory). The recon-all runtime (Freesurfer version 5.3.0, no parallel) for a single subject is usually 7~8 hours. Is this a reasonable runtime given the setting of VM? Only 1-2 hour shorter than my Mac Pro?? Or is there any configuration of VM I should pay attention to set up? Thanks, Yi-Fang Chuang ᐧ ᐧ

3 4

issues with bvecs extracted from dicoms
by Vincent.Beliveau＠i-med.ac.at 09 Feb '19

09 Feb '19

External Email - Use Caution Dear FreeSurfer team! First of all, thanks for the great tools! I have recently started to work with DWI data and there are a few issues I was hoping you could help me with. I have recently found a post on the FSL mailing list mentioning that the bvecs stored in the dicoms header on Siemens scanner are corrected for slice angulation (https://www.jiscmail.ac.uk/cgi-bin/webadmin?A2=FSL;5757c231.1005) I assume this means that, for Siemens dicoms, the bvecs are stored in image orientation? Indeed, the bvecs in the dicoms are different than the ones in the table provided by Siemens. When looking at the preprocessing performed by tracula, the flag --bvec-voxel is used when importing the data from dicoms; isn't this be conflicting with the fact that the bvecs are already in image orientation? A second issue I have is when using the bvecs extracted using tracula to perform tractography in trackvis/diffusion toolkit. For some stange reason, I have to flip the z-axis of the bvec (obtained with either --bvec-voxel or --bvec-scanner) to obtain sensible tractography results. When comparing the bvecs from tracula to the table from Siemens the z-axis is indeed flipped. Unfortunately, this flip issue also occurs in a number of other conversion software (e.g. dcm2niix, mrtrix). Does anyone know where this could be coming from? Note, my data was acquired on a Siemens SkyraFit with software version VE11C. Finally, does anyone know what orientation (image/scanner) is expected for the bvecs when using dti_tracker (in diffusion toolkit)? When looking at the default bvec file passed through the GUI interface to dti_tracker, it seems that it requires bvecs in scanner orientation, but I would like to confirm this. Unfortunately, I did not receive any reply to my emails to support(a)trackvis.org. Perhaps someone on this list knows? Thanks in advance! Vincent.

1 0

Find the fsaverage voxel that corresponds to a voxel in the raw Nifti file
by ts+ml＠rcmd.org 09 Feb '19

09 Feb '19

External Email - Use Caution Dear FreeSurfer experts, I have a raw nifti file created from a stack of DICOM scanner images, let's say it has dimension (162, 172, 188) along the 3 axes. I have also pre-processed this subject in FreeSurfer and have the resulting volume files (e.g., orig.mgz) available. My question is: For a given voxel in the raw nifti file, how could I find the voxel (or coordinate) in the fsaverage subject that corresponds to this voxel? I guess this should be a 2 step process: - first get and apply the affine matrix that leads from the raw file to the Freesurfer pre-processed version (which is resampled to dimension (256, 256, 256) among other changes) - then get and apply the matrix that leads from the pre-processed subject to fsaverage But where exactly can I get these matrices from? I guess the talairach.xfm file and some volume like orig.mgz (using mri_info)? Best, Tim -- Dr. Tim Schäfer Postdoc Computational Neuroimaging Department of Child and Adolescent Psychiatry, Psychosomatics and Psychotherapy University Hospital Frankfurt, Goethe University Frankfurt am Main, Germany

4 3

ExploreDTI Workshop in May@Budapest
by Szabolcs David 08 Feb '19

08 Feb '19

External Email - Use Caution ExploreDTI Workshop - A course on processing, analyzing, and visualizing diffusion MRI data When: 27-29 May, 2019 Where: Budapest, Hungary Details: http://www.exploredti.com/workshop Cheers, Szabolcs >

1 0

[PETSurfer] Intensity normalization of PET images without PVE correction
by Matthieu Vanhoutte 08 Feb '19

08 Feb '19

External Email - Use Caution Dear Douglas, Is it possible to use mri_gtmpvc command in order to intensity normalize PET images without applying PVE correction by setting --psf to 0 ? Best, Matthieu

3 18

Jump to page:

2026

2025

2024

2023

2022

2021

2020

2019

2018

2017

2016

2015

2014

2013

2012

2011

2010

2009

2008

2007

2006

2005

2004

Freesurfer February 2019