External Email - Use Caution Dear Douglas
Thank you very much for your suggestions. Regards Ramesh On Tue, 6 Apr, 2021, 7:03 PM Douglas N. Greve, <dgr...@mgh.harvard.edu> wrote: > Twice the same image at 1x1x1, then use mri_robust_template to register > and average them together > > On 4/6/2021 8:10 AM, Ramesh Babu wrote: > > External Email - Use Caution > Dear Eugenio and Philipp, > > Thank you very much for your suggestions. Could you please give more input > on "acquire the T1WI double and average it after coregistration, this > increases the SNR". > > Should aquire twise the same sequence with 1x1x2 voxel dimension? > > Thanks > Ramesh > > > On Fri, 2 Apr, 2021, 9:00 PM Iglesias Gonzalez, Juan E., < > jiglesiasgonza...@mgh.harvard.edu> wrote: > >> That all sounds right, thanks a lot Philipp! >> >> >> >> >> >> Juan Eugenio Iglesias >> >> Senior research fellow >> >> CMIC (UCL), MGH (HMS) and CSAIL (MIT) >> >> *MailScanner has detected a possible fraud attempt from >> "secure-web.cisco.com" claiming to be* >> http://secure-web.cisco.com/1oAFYauOAeFEI_KJ-fkusgflgO_3xjRHgp7o7CJ3qp41OmNYAHMlvp6Zy_mjFrQna2xraD05zLX72T9k2ZNBxJHPp1lNSv83SmEbFU-GoXpEbCDc6Q36FWCkmfvBgltRRW_zqFZ58dkXw9EZSUQecxsHx9d2bRyl43Zs-sEfD1usXImJGYxchdZJAIb7dU6dJ-hMgC4PeXJDUIO_QfEwqT5pH-JkIZcHhI6CiPacx2HMtkfH3Uq49XZ3cLxtL4H89WL1NSermiy9IwrlG1XBASQ/http%3A%2F%2Fwww.jeiglesias.com >> <http://secure-web.cisco.com/1yAlNRge1To1jCEouu9JnBYJFnIJRo-86GCJ4EIWmAyj8pkkdBifGwyirgDc1KI-N6H7_dg4rBnLgE3CaKBeQuxL7GotNy9SzxKSD4OusIQrdGgcD_E0ObeWLPWYbYhFPgBDLEjcGPr-D8PT-k8bLD71quTve1q2fA_-MJY73fb-zPWX2QNDMT39_ceuRLWK8XGl18IGjSIXm6QeDK2erHCdQTO-rww0uRlSIph9mtjeVoEggFnM0sluSy0XceT-MPg9TJwCFg8RuNNq4J20pSw/http%3A%2F%2Fwww.jeiglesias.com> >> >> >> >> >> >> >> >> >> *From: *<freesurfer-boun...@nmr.mgh.harvard.edu> on behalf of "Saemann, >> Philipp" <saem...@psych.mpg.de> >> *Reply-To: *Freesurfer support list <freesurfer@nmr.mgh.harvard.edu> >> *Date: *Friday, April 2, 2021 at 03:51 >> *To: *Freesurfer support list <freesurfer@nmr.mgh.harvard.edu>, Umesh >> Rurdrapatna <umes...@gmail.com> >> *Subject: *Re: [Freesurfer] 2mm thick image for hippocampal segmentation. >> >> >> >> * External Email - Use Caution * >> >> Hi, >> >> >> >> I try to answer but Eugenio may also add comments. Several points that >> are important: >> >> - 1.5 Tesla and 1x1x1 mm3 are at the limit of what the algorithm can >> manage. >> >> - Post-aquisition reslicing to a higher resolution does not really >> increase the information content. Internally the algorithm works at a much >> higher resolution, anyway. >> >> - If possible, switch to 3 Tesla. >> >> - If possible and this is a prospective study, add a coronal T2 image and >> use the bi-channel option. See papers of Iglesias et al. on this. >> >> - What you could also do on a 1.5 T is acquire the T1WI double and >> average it after coregistration, this increases the SNR. >> >> - Generally, isometric resolutions are good due to the symmetry, of >> course. >> >> - Also on 1.5 T, you may go bit below 1 mm with good head immobilization, >> and a longer scanning time. BRAVO in general is a good T1 option. >> >> >> >> Best, >> >> Philipp >> >> >> ------------------------------ >> >> *Von:* freesurfer-boun...@nmr.mgh.harvard.edu < >> freesurfer-boun...@nmr.mgh.harvard.edu> im Auftrag von Ramesh Babu < >> mgrameshbabu2...@gmail.com> >> *Gesendet:* Freitag, 2. April 2021 09:29 >> *An:* Freesurfer support list; Umesh Rurdrapatna >> *Betreff:* Re: [Freesurfer] 2mm thick image for hippocampal segmentation. >> >> >> >> * External Email - Use Caution * >> >> Dear experts, >> >> Sorry for reposting. I am expecting some response from experts, so that I >> can proceed with confidence. >> >> For our project work, we are looking for hippocampal and its >> subfield volumes. Using GE 1.5T scanner, we tried a 3D BRAVO sequence with >> 1x1x1 resolution, 256x256x160 dimension with 8* flip angle which produced >> images with a lot of noise. Then we tried the same sequence with 1x1x2 >> resolution, and 256x256x80 FOV, which produced a clean image without noise. >> When we reformatted the images, it produces 0.5x0.5x1 resolution with >> 512x512x172 dimension. >> >> >> >> Is this sequence good for hippocampal volume estimation and subfield >> segmentation (also for whole-brain VBM analysis)? >> >> Could you please suggest to me a correct sequence, if need to be changed? >> >> >> >> Regards >> >> Ramesh >> _______________________________________________ >> Freesurfer mailing list >> Freesurfer@nmr.mgh.harvard.edu >> *MailScanner has detected a possible fraud attempt from >> "secure-web.cisco.com" claiming to be* >> https://secure-web.cisco.com/17suehtrGEpDtQ5EXLhVOfQrRIUslZ-oteK8Gfy-y1RsK9R1ugl_2hGqxDgYB_-mq6NsQf__ZufaRoruZ-eI8-xmEzhq86cclq0zzde2jD2TjKirnRHySuNSMLbD-QDQWw-m98jaBDL4noUKjJtfZJnESb1qFzTHUcJUvT9zBW-j2UO_S4Tu4BrdUmQVzTx9i4VaHJidmJEVCD9a0efIeXj03hSqZ01Yo11LevdoNa7-j0kkHFq01jl114BXbjpTI_PlIOJehGVz9FASYpzLorg/https%3A%2F%2Fmail.nmr.mgh.harvard.edu%2Fmailman%2Flistinfo%2Ffreesurfer >> <https://secure-web.cisco.com/1IXus-BXNwSxxsWt0Hl4GNJkM1JdHvv3SmnEoV0r7QyM62LQaQ7GOor7RtRN0aQzfhFM7lc_9Uu5fcLfv9rDBmaLelquFxD0i5EeJz7dRB1fSkcrH9OXh7CcxyQUdtB4YnGDLHG1bIPRqDN88-MQD4DLOCFxhRwE-yMzpgybXDc7HTRizMdSWlMKBuA-Ut2s6ZjmZ1o1v6hOcCdFt73IOXO-n12alCMDKQF2h4U1gnWzOiaxIt45LuwnOsHIljxgM20xQqjqxBim8X_oH_yng5Q/https%3A%2F%2Fmail.nmr.mgh.harvard.edu%2Fmailman%2Flistinfo%2Ffreesurfer> > > > _______________________________________________ > Freesurfer mailing > listfreesur...@nmr.mgh.harvard.eduhttps://mail.nmr.mgh.harvard.edu/mailman/listinfo/freesurfer > > > _______________________________________________ > Freesurfer mailing list > Freesurfer@nmr.mgh.harvard.edu > https://secure-web.cisco.com/17suehtrGEpDtQ5EXLhVOfQrRIUslZ-oteK8Gfy-y1RsK9R1ugl_2hGqxDgYB_-mq6NsQf__ZufaRoruZ-eI8-xmEzhq86cclq0zzde2jD2TjKirnRHySuNSMLbD-QDQWw-m98jaBDL4noUKjJtfZJnESb1qFzTHUcJUvT9zBW-j2UO_S4Tu4BrdUmQVzTx9i4VaHJidmJEVCD9a0efIeXj03hSqZ01Yo11LevdoNa7-j0kkHFq01jl114BXbjpTI_PlIOJehGVz9FASYpzLorg/https%3A%2F%2Fmail.nmr.mgh.harvard.edu%2Fmailman%2Flistinfo%2Ffreesurfer
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