Freesurfer April 2021

freesurfer@nmr.mgh.harvard.edu

104 participants
144 discussions

Unit of the Numbers in cache.th40.neg.y.ocn.dat
by Na, Xiaoxu 17 Feb '24

17 Feb '24

External Email - Use Caution Dear Freesurfer Experts, As I'd like to extract the average value of each subject in the cluster after running group analysis, may I know the unit of these numbers? Since the one I'm running is surface area, and the cluster is 444mm^2, all the numbers in the file cache.th40.neg.y.ocn.dat is in the range of [0.55 1.05], may I know if this is correct and if so, how the unit is for those? Thanks a lot! ClusterNo Max VtxMax Size(mm^2) MNIX MNIY MNIZ CWP CWPLow CWPHi NVtxs WghtVtx 1 -4.8321 40067 444.11 -58.1 -16.6 -23.9 0.0002 0 0.0004 670 -2784.11 Regards, Xiaoxu ---------------------------------------------------------------------- Confidentiality Notice: This e-mail message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message.

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Extract single time frame
by Rockers, Elijah D. 16 Oct '22

16 Oct '22

Hello again, I have a large time series in dicom or .nii format. I am interested in extracting a single time frame from it. I did this before, I believe with freesurfer, but I have somehow forgot the name of the command, and I can't seem to find it. I believe it could be used to specify particular regions of the volume, as well as time. I need the entire volume, still, but only one frame. Thanks in advance! Eli Houston Methodist. Leading Medicine. Ranked by U.S.News & World Report as one of America's "Best Hospitals" in 11 specialties. Named to FORTUNE® Magazine's "100 Best Companies to Work For®" list 10 years in a row. Designated as a Magnet hospital for excellence in nursing. Visit us at houstonmethodist.org. Follow us at twitter.com/MethodistHosp and www.facebook.com/HoustonMethodist. ***CONFIDENTIALITY NOTICE*** This e-mail is the property of Houston Methodist Hospital and/or its relevant affiliates and may contain restricted and privileged material for the sole use of the intended recipient(s). Any review, use, distribution or disclosure by others is strictly prohibited. If you are not the intended recipient (or authorized to receive for the recipient), please contact the sender and delete all copies of the message. Thank you.

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Reliability and sensitivity of two whole-brain segmentation approaches − ASEG and SAMSEG
by Donatas Sederevicius 28 Aug '22

28 Aug '22

External Email - Use Caution A new pre-print paper comparing two FreeSurfer’s whole-brain segmentation methods - ASEG and SAMSEG is now available (see the link below). The study is of great interest to many researchers in the field, providing new insights and guiding the selection of the processing method. https://www.biorxiv.org/content/10.1101/2020.10.13.335737v1

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Postdoctoral position: Neuroimaging, PCAN lab, University of Calgary, Canada, 2 years
by Alexandru Hanganu 16 Jun '21

16 Jun '21

External Email - Use Caution Dear All, The PCAN lab: http://pcanlab.ca has a two-year funded postdoctoral research fellow position under the supervision of Dr. Oury Monchi starting immediately to work on the following project: *Neuroimaging and other predictors of cognitive and neuropsychiatric evolution in Parkinson’s disease using multi-modal MRI imaging techniques and machine learning.* The project is funded by the Canadian Institutes of Health Research (CIHR) . It involves longitudinal analyses of cortical thickness, tractography and BOLD resting-state fMRI analyses and will benefit from collaborations with Dr. Alexandru Hanganu at the Department of Psychology of the University of Montreal. Other collaborators include Dr. Nils Forkert head of the Medical Imaging Processing and Machine Learning laboratory. A special focus will be given to the neural origins and predictors of Mild Behavior Impairment (MBI) in Parkinson’s disease in collaboration with Dr. Zahinoor Ismail who has led the development of the MBI-checklist. The project will make use of an existing longitudinal study containing structural, diffusion weighted imaging and functional MRI, neuropsychological and behavioural assessment, and genotyping at three time points. The PCAN lab has been a pioneer in using different neuroimaging techniques to study the origins and evolution of cognitive more recently neuropsychiatric deficits in Parkinson’s disease with the ultimate goal of early prediction of dementia in the disease. Other interests include the function and application of neuromodulation techniques such as transcranial magnetic stimulation, Transcranial direct stimulation and low intensity focused ultrasound. The PCAN Lab is located in the Healthy Brain Aging labs of the Hotchkiss Brain Institute part the Foothills Campus of the University of Calgary. The Foothills campus is home to the Seaman Family MR Research Centre which host a General Electric 3T research dedicated MRI scanner. Requirements of the position include a PhD in Neuroscience, biomedical engineering, biomedical sciences, or Psychology with experience in the analysis of one or multiple MRI neuroimaging techniques such as cortical thickness/volumetry (e.g. *Freesurfer, FSL*), functional connectivity (e.g. *PPI, ICA, graph theory*), diffusion weighted imaging (e.g. *Dipy, MRTrix, FSL*). Some fluency in computer programming (e.g. *Linux, Unix, MATLAB, or Python)* is also required as well as the ability to write scientific peer-reviewed manuscripts. Please send applications (Cover letter, CV, and the name of 2 references including current supervisor) to Oury Monchi: oury.monchi(a)ucalgary.ca

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mris_anatomical_stats() for ODI maps inflated to surface
by Jensen, Alexandria 27 May '21

27 May '21

External Email - Use Caution Hello fellow Freesurfer users, I am attempting to reproduce the analysis conducted by Parker et al. in their 2018 paper, “Cortical microstructure in young onset Alzheimer's disease using neurite orientation dispersion and density imaging” (https://secure-web.cisco.com/1UgnQVFBMbbUsDXUzai5AvAOzqeQ34tRV2D60a4CwFPoV9…) Cortical reconstruction of the T1 structural image was done in Freesurfer and NODDI processing using the NODDI toolbox in Matlab. The final steps I am attempting to complete include (1) projecting the ODI/NDI maps to an inflated surface to create surface maps (2. Materials and Methods, 2.5 Diffusion-weighted MRI processing); and (2) calculating mean ODI/NDI values across both hemispheres for a selected number of ROIs from the Desikan parcellation (2. Materials and Methods, 2.6 Cortical ROIs). The Parker et al. paper has provided the Freesurfer functions used in each of these final steps, but I am getting stuck on step (2) and am now worried that I have made an error in step (1). Below is the code I have written so far to project an ODI map onto an inflated surface: bbregister \ --s freesurfer \ --mov odi.nii \ --init-fsl \ --reg register.dat \ --dti tkregister2 \ --s freesurfer \ --mov odi.nii \ --reg register.dat \ --surf mri_vol2surf \ --src odi.nii \ --out odi_in_cortex.nativespace.mgh \ --srcreg register.dat \ --hemi lh \ --projfrac 0.5 When I load lh.inflated, the lh.aparc.DKTatlas.annot annotation file, and the odi_in_cortex.nativespace.mgh overlay in Freeview, things seem to be correct. The issue I have is when I try to use mris_anatomical_stats(). I have tried different combinations of label and annotation files but am either getting errors or no errors but also no output. Any guidance would be much appreciated! I am new to Freesurfer and have been learning it as part of my graduate research assistantship. I am using Freesurfer version 7.1.1 on a macOS Catalina, version 10.15.7 operating system for reference. Cheers, Alexandria Jensen

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mask error in glm_fit
by Haley Park 27 May '21

27 May '21

External Email - Use Caution Hello, I am trying to run a correlational analysis with glm_fit on a masked area with the code: foreach hemi (lh) foreach smoothness (10) foreach meas (volume thickness) mri_glmfit \ --y {$hemi}.{$meas}.{$study}.{$smoothness}.mgh \ --fsgd FSGD/{$study}.fsgd \ --C Contrasts/Scores_Slope.mtx \ --surf fsaverage {$hemi} \ --mask lhYeo2011_7NetworksConfidence_N1000.mgz \ --glmdir {$hemi}.{$meas}.{$study}.{$smoothness}.glmdir end end end I get the error message: ERROR: dimension mismatch 1 between y and mask I've also tried to run it with the .nii file found at https://secure-web.cisco.com/1sTopz8rXlJoh4VSQL7P0DYm1ff7H5Crs0Qg3iAG1M6HD6… Any help would be appreciated! Haley

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Infant Freesurfer exiting without error
by COLLEEN PLETCHER 13 May '21

13 May '21

External Email - Use Caution Hi, I am trying to run infant freesurfer using the --segfile and --masked options. When I attempt to run it, it runs for a bit and then I get this: USAGE: mri_or <options> fname1 fname2 .. After this, the program exits. I am not getting any error, so I am confused about why it is exiting suddenly? Thank you very much! -Colleen

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Sulcal probability maps
by Kristi Drudik 12 May '21

12 May '21

External Email - Use Caution Good afternoon, I hope this email finds you well. I am in the process of "painting" MRI surfaces from the Human connectome project in FreeSurfer, meaning creating labels on the surfaces to analyze sulcal morphology. We are interested in the spatial variability of the sulcus and thus, want to create surface spatial probability maps using FreeSurfer (please see attachment for an example of such surface probability maps). These maps would represent the likelihood of each vertex on the FreeSurfer fsaverage surface belonging to the sulcus of interest (from 0% to 100%). To obtain these probability maps, I: * Painted the sulcus of interest on the surface by creating a .label file. * Registered this .label file to fsaverage (mri_label2label) * Converted the .label file to vol (mri_label2vol) * Converted it to a surface file (mri_vol2surf) * Concatenated the data to create an average (mri_concat --mean) * Blurred the data and loaded the blurred average as an overlay onto the fsaverage pial (mris_fwhm) Because this seems very convoluted, my question becomes: Is there a more direct way to generate these maps from the labels themselves, rather than going from label to vol, then back to surf? Finally, I would like these maps to represent a 0-100% range of each vertex in fsaverage belonging to the sulcus of interest. However, this method creates a 0-1 range (please see colour bar in attachment). Is there a way to change this to a percentage? Thank you very much for your time and help. Please let me know if you have any questions. Best, Kristi Kristi Drudik Ph.D. Student, Clinical Psychology Montreal Neurological Institute McGill University Montreal, Canada

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Cluster correction at subject level using -log10(p) values
by Leonardo Tozzi 12 May '21

12 May '21

External Email - Use Caution Dear Experts, I am running an analysis where I have -log10(p) values on the cortical surface of some subjects stored as a MGH file. I would now like to run a cluster level correction on these data at the level of each individual subject using mri_mcsim followed by mri_surfcluster and I would like to constrain my inference to a ROI. I have a few questions. First of all, is it correct that I should to a -log10(p) transform on my p values before entering them in mri_surfcluster? Second, will the csd generated by mcsim be valid to feed in mri_surfcluster since the values are a -log10(p) transformed? Does mcsim -log transform the gaussian noise it uses at some point or is this not necessary? My calls to the two methods are as follows (for one hemisphere): First the mcsim: mri_mcsim --o “${subject}_mcsim_lh_${roi}" --base mc-z --surface ${subject} lh --nreps 10000 --label $roi Then the mri_surfcluster: mri_surfcluster --in "/${subject}_lh_${roi}_neglog10p_signed.mgh" \ --csd "${subject}_mcsim_lh_${roi}/fwhm05/abs/th30/mc-z.csd" \ --clabel "${subject}/label/lh.${roi}.label" \ --cwsig "${subject}_lh_${roi}_neglog10p_abs_clu05.mgh" \ --vwsig "${subject}_lh_${roi}_neglog10p_abs_vox05.mgh" \ --sum "${subject}_lh_${roi}_neglog10p_abs_summary.txt" \ --thmin 3 \ --surf white \ --subject ${subject } \ --hemi lh \ --ocn “${subject}_lh_${roi}_neglog10p_abs_clu05_clunum.mgh" \ --cwpvalthresh 0.05 In the call of mri_surfcluster, I want a cluster forming threshold of p=0.001, which would correspond to -logp(0.001)=3. Is it correct that the argument --thmin should be expressed as -log10(p) but the parameter cwpvalthresh should be p? The reason why I think I did something wrong is that I get a lot of clusters from this analysis, sometimes >15 per individual. This makes me think that the correction might not be as stringent as I would like to. Thank you, Leonardo Tozzi, MD, PhD Williams PanLab | Postdoctoral Researcher Stanford University | 401 Quarry Rd ltozzi(a)stanford.edu<mailto:ltozzi@stanford.edu> | (650) 5615738 Connect with us! [signature_1075933358]<https://secure-web.cisco.com/154LqJFzFLISeYtGLsUgwToWD-mN0G4thIfubhtThzJ6F9…> [signature_1282923475] <http://secure-web.cisco.com/11JA0cps0LSyc_YKkvLkjj53ioS8G144vcOsjQghqMz-F2M…> [signature_911042299] <https://secure-web.cisco.com/1Mkao1uevqs0RL-8o0FG2efSSKGQAOwrHeahbv3dcsTbir…>

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FA map registration to T1
by Russo, Andrew William 10 May '21

10 May '21

Hello FreeSurfer Developers, I am registering FA maps to T1 for a group of subjects with MS and in many cases the registration is poor for the anterior corpus callosum (attached), cerebellum, pons, and temporal lobe. I am using the following commands (FreeSurfer version 6.0): bbregister \ --dti \ --reg diff2T1_reg.dat \ --mov eddy_corrected_b0.nii.gz \ --s subject_temp mri_vol2vol \ --mov dtifit_FA.nii.gz \ --targ orig.mgz \ --o FA2T1.nii.gz \ --reg diff2T1_reg.dat Do you have any suggestions for improving this registration? Thank you, Andrew Andrew Russo Clinical Research Coordinator Multiple Sclerosis Imaging Lab Massachusetts General Hospital 149 13th Street | Boston, MA 02129 617-726-7531

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Freesurfer April 2021