Freesurfer

freesurfer@nmr.mgh.harvard.edu

19 participants
30088 discussions

retinotopy sig.nii file
by Thomas Janssens 09 May '11

09 May '11

Hi, I performed a retinotopy analyses with freesurfer using selxavg3-sess. One of the nii-files that is created with this command is sig.nii. How is the significance map in sig.nii calculated for retinotopy? which p-values are used in this calculation? Thanks! Thomas

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Re: [Freesurfer] subcortical volume and qdec
by 汪贵宏 09 May '11

09 May '11

Thanks for your reply,doctor Nick: I have done the subcortical volume analysis simply by working with the "aseg.volume.stats" txt in the "stats_tables" file with the SPSS soft . But it results no difference,so, as this analysis was done based on the ROI,if the analysis can be done by each voxel ,if can ,how? As I can see ,I think it can not ,not as the situation in the analysis of cortical thickness ,the subcotical volume is an entirety,such as the amygdala or hippocampus , if it has difference,it will be the total volume difference ,not some part of the the area.But I am not sure about it,is it right? thanks , wang At 2011-05-04 22:32:18，"Nick Schmansky" <nicks(a)nmr.mgh.harvard.edu> wrote: >wang, > >qdec doesnt yet support analysis of subcortical structures in the way i >think you were expecting. that is, currently only surface measures (by >default thickness), is selectable as the independent variable. a >subcort volume is not yet selectable (its output results would be bar >charts, not a surface display). you can do a subcortical volume >analysis by working with the aseg.stats file directly in some stats >program (or mri_glmfit). > >so if a particular volume measure is selected via the stats import >option, and it is selected as a possible factor, and that factor is >selected as a regressor in the Design window, then when an analysis is >run, it is entirely possible (and very likely) that there is no change >in thickness value given a particular subcortical volume. the one >exception i have seen for this is hippocampal volume, which does have an >effect on cortical thickness between controls and AD patients. > >n. > > >On Wed, 2011-05-04 at 11:18 +0800, 汪贵宏 wrote: >> Dear freesurfer experts: >> >> I had processed my data with recon-all, and also ,I had compared >> the cortical thickness difference between the con and pat with >> qdec .however,when i I try to compare the sub-cortical volume >> difference between con and pat ,the results were the same as the >> thickness,even in Analysis Results window,the option is not changed,as >> the "Does the average thickness differ between con and pat?" So, I >> have no idea about it,because I chose the ASEG.VOLUME in the "Stats >> Data Import" window. >> >> In addition ,I wander whether the volume differ comparison is >> processed based on ROI or vertex? >> >> Did anyone can help me with any suggestion. >> >> thank you >> wang >> >> >> >> >> ______________________________________________________________________ >> 体验网易邮箱2G超大附件，轻松发优质大电影、大照片，提速3倍! >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer(a)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.

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cvs_register: missing surf2vol on MAC
by Martin Kavec 09 May '11

09 May '11

Hi all, I am trying to run mri_cvs_register on MAC distribution o Freesurfer 5.0, but it is failing on surf2vol. Looking into the $FREESURFER_HOME/bin, surf2vol is completely missing. Could you please provide this file? Thanks, Martin

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optimal voxel size
by Wenger, Elisabeth 09 May '11

09 May '11

Dear Freesurfer experts, I am currently planning a study in which I want to investigate changes in gray matter due to training on structural MR images. I heard some rumors that although FreeSurfer can of course process images with different voxel sizes, it always somehow "transforms" the voxel size to 1 x 1 x 1, irrespective of the originally obtained image resolution. I've been wondering if something has changed in this regard, that is, whether FreeSurfer is now capable of maintaining a higher resolution (eg, 0.8 mm) throughout all the analysis steps? As I am looking for very very tiny changes I would like to acquire images with 0.8mm resolution. But if FreeSurfer has to convert these images with the help of some estimation processes at some point of the reconstruction, I would rather like to acquire 1 x 1 x 1 images in the first place. Thank you so much for your help! All the best, Elisabeth

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mailing list
by shahriar ahadpour 08 May '11

08 May '11

Dear i got some problems with downloading the software,is it possible recieving the package by attachment?

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Flattened surface visualization using matlab
by Gabriele Arnulfo 07 May '11

07 May '11

Dear freesurfer experts, I've surfed the web looking for some example on how to visualize the flattened surface using matlab, but none has appeared so far. Does this task have been already addressed by someone? Cheers, -- Gabriele Arnulfo PhD Student Bioengineering Department of Systemistic, Telematic and Informatic University of Genoa, Italy Viale Causa 13, 16100

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Updated program: Workshop on Diffusion Tensor Imaging in San Francisco on June 7, 2011 (fwd)
by Bruce Fischl 06 May '11

06 May '11

FYI ---------- Forwarded message ---------- Date: Wed, 4 May 2011 16:35:34 -0700 From: "Weiner, Michael" <Michael.Weiner(a)ucsf.edu> To: "Weiner, Michael" <Michael.Weiner(a)ucsf.edu> Subject: Updated program: Workshop on Diffusion Tensor Imaging in San Francisco on June 7, 2011 To everyone interested in MRI: We are organizing a workshop entitled "DIFFUSION IMAGING: Theory, Methods and Clinical Research Applications" on Tuesday, June 7, 2011, to be held at the UCSF Mission Bay Campus. We believe that this will be highly informative and please come if you are interested, and please pass this email on to anyone you know who might be interested. Michael W. Weiner, M.D. Director, Center for Imaging of Neurodegenerative Diseases (CIND) http://www.cind.research.va.gov/ San Francisco VA Medical Center 4150 Clement Street (114M), San Francisco CA, 94121 USA Professor of Medicine, Radiology, Psychiatry, and Neurology University of California, San Francisco, USA Principal Investigator: Alzheimer's Disease Neuroimaging Initiative (ADNI) http://www.adni-info.org/ Principal Investigator: Resource for MRI of Neurodegenerative Diseases http://www.rrmind.research.va.gov/ Scientific Data Sharing Project http://scientificdatasharing.com/ Tel: (415) 221-4810 x 3642, FAX (415) 668-2864 In Emergency pager is (415) 302-0590

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Demeaning and correlation in DODS
by cgomez＠bidmc.harvard.edu 06 May '11

06 May '11

Hi Freesurfers, I’ve been using freesurfer5, qdec 1.4 and I have some questions about it. 1-I’ve used age as a nuisance variable in my analysis (DODS). When I use demeaned age I obtain a different result if I use ‘real’ age value, which is your the recommendation? 2-When I use DOSS model, which is the meaning of the question: ‘Does the thickness-performance correlation differ between A2 and A3?’ If you are using DOSS model both groups have the same slope and the same correlation value, isn’t it? Moreover, the results (areas) that I obtain are the same (but with colors reversed) as those obtained in ‘Does correlation between thickness and performance, accounting for group, differ from zero?’ These are the contrasts: lh-Avg-thickness-perf-Cor ----------------------- Does the correlation between thickness and perf, accounting for group, differ from zero? Nuisance factors: Gender Age 0.000 0.000 1.000 1.000 0.000; lh-Diff-bed-cnt-Cor-thickness-perf ----------------------- Does the thickness--perf correlation differ between A2 and A3? Nuisance factors: Gender Age 0.000 0.000 1.000 -1.000 0.000; When the order Xg.dat is: group1 group2 performance gender age. So, the contrast not seem correct at all..?? Thanks in advance for your help. Cleo.

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RAS to MNI coordinates of a label
by Yolanda Vives 06 May '11

06 May '11

Hi all, I am interested in obtaining the MNI or talairach coordinates of a label. The procedure that I have performed is the following: First of all I have performed a QDEC analysis. From the results, I have drawn a label of a significant area of the brain, that corresponds to the cingulate. Afterwards, I have used the matlab function read_label to obtain the RAS coordinates of this label. To transform these coordinates into mni coordinates, I have read that if v = [R A S 1]' and X matrix is the matrix from talairach.xfm, then vMNI = X*v Taking this into account, I have used the X matrix from the talairach.xfm of "fsaverage" (where the results of qdec are mapped). This matrix is 1.0 0.0 0.0 0.0 0.0 1.0 0.0 0.0 0.0 0.0 1.0 0.0 so vMNI is the same as v. When I introduce v (or vMNI) coordinates into a MNI atlas, I don't obtain the cingulate. Could you please help me with this procedure? Thank you in advance, Yolanda

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Smaller Virtual Machine
by Fidel 05 May '11

05 May '11

Hi all, I have been trying the virtual disk image, and it works well. Nevertheless, I think that more than 7GB is a lot of space if somebody wants to use it as a Virtual Machine in a cloud environment, in which you are charged for used storage and maybe for used bandwidth in the data communication. Is anybody thinking about creating a lighter version of this virtual disk image? Thanks and best regards, Fidel.

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