Freesurfer February 2020

freesurfer@nmr.mgh.harvard.edu

96 participants
143 discussions

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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Job ad: MRI physicist
by Keith Schneider 07 May '21

07 May '21

External Email - Use Caution The Center for Biomedical and Brain Imaging (CBBI) is a core imaging facility at the University of Delaware dedicated to scientific research. It is equipped with a Siemens Prisma 3T MRI scanner, Bruker 9.4T small bore MRI scanner, TMS, and MRI-compatible EEG. It supports a wide range of scientific investigations through imaging of humans, animals and materials. Under general direction of the CBBI Manager, the MRI Physicist is responsible for supporting the operations of the Siemens and Bruker MRI scanners. The MRI Physicist is expected to contribute to both research and training efforts that will include pulse sequence programming, parameter and image quality optimization, protocol design, scanner operation, technical support and user training. The candidate will be expected to maintain a broad knowledge of state-of-the-art MRI technology and equipment. The incumbent must have excellent communication and organizational skills, the ability to positively interact with a diverse group of MRI users, and a strong motivation to learn new MRI techniques. MAJOR RESPONSIBILITIES: • Pulse sequence programming on Bruker 9.4T and Siemens 3T MRI scanners • Assist users on appropriate choice and use of coils • Technical liaison for obtaining sequences or protocols for non-standard imaging (e.g. cardiac, musculoskeletal) from Siemens and other sites • File reports as needed for WIP sequences and Siemens MRA • Ensure data quality from the viewpoint of machine fundamentals • Technical support 9.4T and 3T scanners • Protocol design and testing for 9.4T scanner, including imaging of live animals and awake animals; as-needed for 3T • Routine quality assurance for 9.4T and 3T MRI scanners • Train users, including students, on use of 9.4T and 3T MRI scanners • Help users optimize pulse sequence parameters to maximize SNR and avoid imaging artifacts • Consult on image analysis, as needed • Review journals and abstracts to keep abreast of new developments • Collaborate with ongoing research as needed; may have independent research projects if desired • Consult users about imaging details for manuscript preparation and grant applications, as needed • Perform miscellaneous job-related duties as assigned QUALIFICATIONS: • PhD in MR physics or MS with equivalent experience • expert understanding of MR physics, image acquisition, signal processing, imaging processing and image reconstruction • MR pulse sequence programming • Experience with Bruker and Siemens MRI scanners • MRI scanning experience with both humans and animals—willing to handle animals • Ability to design experiments, optimize MRI protocols, troubleshoot image artifacts, analyze data, and interpret results • Knowledge of functional MRI, DTI, MRS, T1/T2 relaxation and perfusion • Siemens IDEA and ICE certification (or ability to obtain) http://careers.udel.edu/cw/en-us/job/493998/mri-physicist-research-office <http://careers.udel.edu/cw/en-us/job/493998/mri-physicist-research-office> For further information, contact me. keith ----- Keith Schneider Director, Center for Biomedical and Brain Imaging Associate Professor Department of Psychological and Brain Sciences University of Delaware

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Correct for sulcuses & ventricles size
by John Anderson 13 Dec '20

13 Dec '20

External Email - Use Caution Dear Freesurfer experts, I have two groups of subjects (healthy and patients). The patients have different degrees of atrophy. Looking into the individual scans, the subjects are largely different in the space between the sulcuses and the size of ventricles. My questions are: 1. Is there any way to correct for these differences in the surface based analysis? 2. Including eTIV covariate does it help in this case? 3. Does the resampling to "fsaverage" overcome the challenge of these differences between the subjects? I appreciate any advice, John

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Re: [Freesurfer] aparcstats2table error
by Devika K 15 Jul '20

15 Jul '20

External Email - Use Caution I tried doing cortical parcellation using Destrieux atlas. I ran the aparcstats2table command from the SUBJECTS_DIR directory containing all of the output from recon-all. But I got an error, PFA. Do I need to run any other commands before running aparcstats2table command, I would be grateful if anyone could help me to resolve this issue. Many thanks in advance. Regards Devika K Research Scholar, Dept of EEE e: k_devika(a)cb.students.amrita.edu Amrita Vishwa Vidyapeetham Coimbatore, India

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Error with "recon-all -make all" following multiple manual editing
by Matthieu VANHOUTTE 03 Jul '20

03 Jul '20

External Email - Use Caution Dear Freesurfer's experts, Havng done multiple types of manual editing in two subjects, I relaunched the recon-all process (Freesurfer 6.0.1) with the flag "-make all". However, during the process, I goth for both subjects the following error message: / / /make: *** [/netapp/vol2_agewell/pro/IMAP/imap_mvh/FS6.0.1/awellv1s097/mri/aseg.presurf.mgz] Error 1/ /recon-all -s /netapp/vol2_agewell/pro/IMAP/imap_mvh/FS6.0.1/awellv3s024 -ccseg ERROR: Flag -ccseg unrecognized./ Following the troubleshooting site (https://surfer.nmr.mgh.harvard.edu/fswiki/FsTutorial/TroubleshootingDataV6.0) I have over-writed the "recon-all.makefile" file since I use the 6.0.1 version of Freesurfer. Thanks for helping. Best, Matthieu

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group analysis of large data sets
by Wang, Xin 22 Apr '20

22 Apr '20

Hello, FreeSurfer Group, What is the maximal matrix size for glm_fit process? How to use FreeSurfer for group analyses of more than 2000 subjects, 128 variables, and 128 Classes? Thank you. Xin

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eTIV vs. ICV
by Alexopoulos, Dimitrios 20 Apr '20

20 Apr '20

External Email - Use Caution The eTIV from FS 6.0 has been used by many as a normalization measure for regional volumetric analyses. I know it is not a true voxel count but does it conceptually include extra-axial CSF or is it more a total tissue volume? Jim ________________________________ The materials in this message are private and may contain Protected Healthcare Information or other information of a sensitive nature. If you are not the intended recipient, be advised that any unauthorized use, disclosure, copying or the taking of any action in reliance on the contents of this information is strictly prohibited. If you have received this email in error, please immediately notify the sender via telephone or return mail.

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mri_vol2vol
by Benjamin Ineichen 30 Mar '20

30 Mar '20

External Email - Use Caution Dear Freesurfer experts, In order to transform a segmentation mask (example.mgz) from native so standard MNI space I ran: mri_vol2vol --talres 1 --interp nearest --mov example.mgz --s 001.mgz --targ $FREESURFER_HOME/subjects/fsaverage/mri/orig.mgz --regheader --o example.mni305.mgz the output example.mni305.mgz did somehow transform to a different space as you can see in Screenshot orig where the native mask is white and the transformed mask is red. However, the masks seems to be in a completely different brain region in the native MNI space (Screenshot MNI). But the point of transforming my segmentation mask is that the segmented mask should be in the same brain region but just transformed to the standard space. How can I correct this? Many thanks for the support! /Ben -- ____________________________________ Benjamin Victor Ineichen, MD PhD Karolinska Institutet Center for Molecular Medicine Stockholm, Sweden ineichen(a)protonmail.ch +41 76 391 04 01 Dr. med. et Dr. rer. nat. ETH Benjamin Victor Ineichen Karolinska Institutet Center for Molecular Medicine Stockholm, Sweden ineichen(a)protonmail.ch +41 76 391 04 01

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Flip left-right orientation command
by Miguel Ángel Rivas Fernández 20 Mar '20

20 Mar '20

External Email - Use Caution Dear Freesurfer experts, Which command should I use to flip the left-right orientation of a T1 image?. Actually my image is in PIR orientation, I used the following command mri_info --orientation '/home/rmn/Desktop/study/E03/3d/coanat_E03.nii' *PIR* Thanks in advance, Best regards, -- *Miguel Ángel Rivas Fernández*

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field inhomogeneities and eddy current correction evaluation
by Adam Rytina 08 Mar '20

08 Mar '20

External Email - Use Caution Hello all, how can I evaluate the field inhomogeneities and eddy current correction I performed on my DWI images? Does any metric exist to do so? Thanks a lot in advance Regards Adam

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Freesurfer February 2020