Freesurfer July 2011

freesurfer@nmr.mgh.harvard.edu

129 participants
195 discussions

Atlas coordinates provided by QDEC
by Maria Serra 25 Jul '11

25 Jul '11

Hi FreeSurfer experts, I have a doubt regarding the atlas coordinates that uses QDEC. In the power point titulated "fscoordinates" found in the FreeSurferWiki seems that the coordinates used are aligned with Talairach Atlas, but when you enter de coordinates provided by QDEC in a particular area (Right isthmus for example: -32 -29 26) in a Talairach client software ( http://www.talairach.org/client.html) , the area that it gives you is totally different: Label at (-32, -29, 26) Left Cerebrum, Frontal Lobe, Sub-Gyral, White Matter, * Do you know why this discrepancy is caused for? Thank you in advance, -- Maria Serra PIC (Port d'Informació Científica) Campus UAB, Edifici D E-08193 Bellaterra, Barcelona Telf. +34 93 586 8232 www.pic.es

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Problems with the .Qdecrc file
by dolphinede＠aol.com 25 Jul '11

25 Jul '11

Hi, i am trying to add new measures (pial_lgi) to qdec. I created the .Qdecrc file in my SUBJECTS_DIR/qdec, with the described text (MEASURE1 = pial_lgi), but it does not work, i cannot select in the qdec menu pial_lgi as a dependent variable. A qdec.fsgd file is also in the same place. I also renamed the .Qderc file in qdec.Qdecrc but it is the same. I am using freesurfer version 4.5.0. I am a little bit confused what i can do? Thanks you a lot, Best regards Daniel

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Fwd: questions about high resolution atlas on the Freesurfer
by Jixin Liu 24 Jul '11

24 Jul '11

Dear FS experts, Freesurfer could provide for every participant a standardized partition of the cortex into 66 regional areas. My aim is to use freesurfer to subdivide these regional areas into a set of small and compact regions, resulting in high resolution atlas covering the entire cortex (taken from Hagmann et al. (2008) in PLoS Biol). We tried to used the mris_divide_parcellation fsaverage rh aparc.annot 100 rh_annot_100 (However, this creates a parcellation of long strips per region, that is not a good partition for what we want.) Then, we used the "mris_make_face_parcellation lh.orig $FREESURFER_HOME/lib/bem/ic3.tri ./lh.ic3.annot". The results look nice, but I have the following questions: (1)Can i used the "mris_make_face_parcellation" based on the "aparc.annot"? (2)How can i conver the .annot file into .hdr/.img mask files? I read the introduction about "mri_label2vol", but i was still confused. If i want to convert aparc.annot files in fsaverage, what the input files are for "--temp" and "--seg"? (3)I read the "lh.ic3.annot" in Matlab (read_annotation.m). For "colortable.struct_names", the name is "ic3.tri_vertex_0"(to "ic3.tri_vertex_641"), how to know which brain regions it belong to? how to know each vertex's MNI coordinate? (4)"mris_make_face_parcellation lh.orig $FREESURFER_HOME/lib/bem/ic3.tri ./lh.ic3.annot" . I only see 7 options in: $FREESURFER_HOME/lib/bem/ic[1-7].tri (as per the program usage). Can I specify custom ic*.tri files (and also, how would those be generated)? -- Good Luck ============================================ Life Sciences Research Center Xidian University Xi'an China http://life.xidian.edu.cn liujixin(a)life.xidian.edu.cn liujixin2010(a)gmail.com ============================================

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Problems with mri_label2vol
by Jixin Liu 24 Jul '11

24 Jul '11

i want to convert the ".annot" files to nifti. When i used "mri_label2vol", I used this command mri_label2vol --subject fsaverage --annot $FREESURFER_HOME/subjects/fsaverage/surf/lh.ic3.annot --o test.img --hemi lh --regheader $FREESURFER_HOME/subjects/fsaverage/mri/brain.mgz --temp $FREESURFER_HOME/subjects/fsaverage/mri/brain.mgz But the error is: Number of labels: 0 Annot File: /usr/local/freesurfer/subjects/fsaverage/surf/lh.ic3.annot Template Volume: /usr/local/freesurfer/subjects/fsaverage/mri/brain.mgz Outut Volume: test.img Registration File: (null) Fill Threshold: 0 Label Vox Vol: 1 ProjType: (null) ProjTypeId: 0 ProjStart: 0 ProjStop: 0 ProjDelta: 0.1 Subject: fsaverage Hemi: lh UseNewASeg2Vol: 1 DoLabelStatVol 0 $Id: mri_label2vol.c,v 1.32 2009/10/22 23:35:53 greve Exp $ Template RAS-to-Vox: -------- -1.000 0.000 0.000 128.000; -0.000 -0.000 -1.000 128.000; -0.000 1.000 -0.000 128.000; 0.000 0.000 0.000 1.000; Template Voxel Volume: 1 nHits Thresh: 0 Computing registration based on header RegMat: -------- 1.000 0.000 0.000 0.000; 0.000 1.000 0.000 0.000; 0.000 0.000 1.000 0.000; 0.000 0.000 0.000 1.000; Label RAS-to-Vox: -------- -1.000 0.000 0.000 128.000; 0.000 0.000 -1.000 128.000; 0.000 1.000 0.000 128.000; 0.000 0.000 0.000 1.000; INFO: loading surface /usr/local/freesurfer/subjects/fsaverage/surf/lh.white nvertices = 163842 Reading thickness /usr/local/freesurfer/subjects/fsaverage/surf/lh.thickness Loading annotations from /usr/local/freesurfer/subjects/fsaverage/surf/lh.ic3.annot reading colortable from annotation file... colortable with 642 entries read (originally /usr/local/freesurfer/lib/bem/ic3.tri) annotidmax = 640 Allocating Hit Volume (-2147483648) voxels MRIalloc(256, 256, 256): could not allocate 131072 bytes for 22494th slice Cannot allocate memory Does anyone know, why is that happening and how can I correct it? -- Good Luck ============================================ Life Sciences Research Center Xidian University Xi'an China http://life.xidian.edu.cn liujixin(a)life.xidian.edu.cn liujixin2010(a)gmail.com ============================================

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Question about if there is constant number of vertexes across different brains
by Knut J Bjuland 24 Jul '11

24 Jul '11

Hi I have read (Dale, Fischl et al. 1999) and (Fischl, Sereno et al. 1999) . I have a question about if I understood the tessellation procedure right. There are two vertexes in each voxel, but is the total number of vertex constant across brains. I believe that number of total vertex does not change over brain since it will be difficult to do statically measure if the total numbers of vertex change. Nevertheless, the shape and size of the vertex do change. Is this a correct assumption? Knut J Referanse liste Dale, A. M., B. Fischl, et al. (1999). "Cortical surface-based analysis. I. Segmentation and surface reconstruction." Neuroimage 9(2): 179-194. Fischl, B., M. I. Sereno, et al. (1999). "Cortical surface-based analysis. II: Inflation, flattening, and a surface-based coordinate system." Neuroimage 9(2): 195-207.

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Combining 'accelerated' vs 'non-accelerated' data in ongitudinal analyses
by Irwin, William 23 Jul '11

23 Jul '11

Hello- Our group occasionally encounters patients with various syndromes such that 'excessive' head movement is an issue. One solution on which we rely is acquiring an "accelerated" MPRAGE sequences (Siemens GRAPPA) which takes about ½ the time. For those not familiar with this method, the resulting image is noisier and the contrast-to-noise is reduced. Quantitatively, because of the increased noise in the accelerated acquisition, comparisons of the correlation between regional cortical thickness reveals that the covariance is different between data acquired with the accelerated vs. non-accelerated sequences. If the longitudinal processing stream is used, is the issue of differing covariance between the 2 acquisitions method an issue? If so, does anyone have a suggestion about to deal with this issue? I should add, there is no systematic issue such as one patient group always requires using the accelerated sequence. Regards, Wil

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Aseg and Cerebellum
by Murray, Michael 22 Jul '11

22 Jul '11

Hi all, We've using version 5.1 to conduct a longitudinal study involving over 150 subjects with up to three time points apiece, and we're having some issues with regards to aseg in the areas around the cerebellum. Attached is an image of the problem - some dura or something else is being classified as cerebellum. It's particularly troubling because this issue is present in most of our images, but to varying degrees. We've tried adjusting the watershed parameters (using multistrip) as well as using gcut, but neither method was effective in removing the offending voxels. It seems like our only other option is to manually edit the brainmask.mgz, but with so many subjects and time points, we're wondering if there is another automated fix that we haven't tried. Otherwise, is this something that we'll have to manually fix, or can it be left alone? Thank you, Michael Murray

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PySurfer - A package for visualizing surfaces
by Michael Waskom 22 Jul '11

22 Jul '11

Dear Freesurfers, We are pleased to announce the 0.1 release of PySurfer, a Python-based package for the visualization of surface data from Freesurfer. Please see our website at http://pysurfer.github.com/ for information on how to install the package and a gallery of examples. We hope you'll find it useful in your research! Best, Michael Waskom Alexandre Gramfort Scott Burns

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Re: [Freesurfer] dcm conversion to nii
by Bruce Fischl 22 Jul '11

22 Jul '11

Hi Antonella, for each acquisition you give mri_convert *one* dicom file in that series and it will figure out the rest. You will then have one volume file per series. Something like: mri_convert <one .dcm file in the Ax_PD series) Ax_PD.nii.gz cheers Bruce On Thu, 21 Jul 2011, Antonella Kis wrote: > Good morning Bruce, > > Thank you for your answer and yes, I am posting my question to the list. > > For all my other subjects I had the MRI data converted by somebody else into one file .nii.gz for each subject. My question is how I can > convert the MRI data (.dcm) for a new subject in a .nii.gz file? I have multiple file from MRI: 3DAx_T1, 3DSag_T1, Ax_Flair, Ax_PD, Ax_T2, > BOLD, DTI_15, DTI_32 each of them containing lots of .dcm files. Do I need to convert all of them? If I give mri_convert one slice in each > dicom series and convert each one to it's own volume how I can further use this data? Do I get an .nii.gz for each dicom file? > > I attached a type of file .nii.gz from another subject so you can see what type of files I need to get by conversion. > > Thank you very much. > Antonella > > > From: Bruce Fischl <fischl(a)nmr.mgh.harvard.edu> > To: Antonella Kis <atorok9(a)yahoo.com> > Sent: Wednesday, July 20, 2011 4:12 PM > Subject: Re: dcm conversion to nii > > Hi Antonella > > can you post this type of question to the list so others can answer? I don't think you want them in one file as they probably have > different resolution etc... Give mri_convert one slice in each dicom series and convert each one to it's own volume. > > cheers > Bruce > On Wed, 20 Jul 2011, Antonella Kis wrote: > > > Dear Bruce, > > > > I have the MRI data (.dcm) for my subject p27 within the following files: > > > > 3DAx_T1, 3DSag_T1, Ax_Flair, Ax_PD, Ax_T2, BOLD, DTI_15, DTI_32. > > > > I would like to convert this data into one file.nii.gz. It will be correct if I will run: > > > > mri_convert p27 NPI027.nii.gz? > > > > Will FS know to convert based on this statement all my dcm files into one nii.gz file? If not how should I do it? > > > > > > Many thanks. > > Antonella > > > > > > > > > > > > > > > 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. > > > >

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trac-all -bedp error
by phoebe＠nmr.mgh.harvard.edu 21 Jul '11

21 Jul '11

Hi, I run the trac-all bedp process and it comes up with the following errors: 56 slices processed 56 slices processed 57 slices processed Queuing post processing stage 58 slices processed For some reason the bedpostX process DOES NOT appear to have successfully completed. Please examine your results carefully. /usr/local/freesurfer/stable5_1_0/bin/bedpostx_seychelles: line 281: kill: (12876) - No such process When I look at the processed data in dmri.bedpostx, I couldn't identify the problem. Kindly help. Phoebe. -- ___________________________________ Phoebe Suk-tak Chan, Ph.D. Athinoula A. Martinos Center for Biomedical Imaging Massachusetts General Hospital Bldg. 149, 13th St., mailcode 149-2301 Charlestown, MA 02129 phoebe(a)nmr.mgh.harvard.edu

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Freesurfer July 2011