Many thanks to Donna and Alex! Now I begin to know the meaning of border files and coord files.
Recently, I tried to delineate the flat map with the border file. I used PALS_B12.RIGHT.MCW_2008_06.73730.spec as a template. Then I created a set of grid borders, which around the BA 4, and put the FLAT border file into the Matlab. Then the flat map, which was filled with dots, was delineated well in Matlab. I also export the border file of FIDUCIAL map. Then I used these coordinates data which were stored in that border file to create a 3D matrix, and export this 3D matrix as a nifti file. However, when I merge this nifti image on the ch2.hii.gz (provided by Mricron), the voxels of this 'BA4 border' image were not located around BA 4, and almost of them were located at BA 6. I also try converting the coordinates data into MNI coordinates, but the voxels still not around the BA 4. Therefore, how can I create a correct 3D image with the border file of FIDUCIAL map? Thanks for your help. Long On Thu, Jul 9, 2009 at 11:05 PM, Alexander Li Cohen <[email protected]>wrote: > Yes, > as Donna stated, the 'generated Cartesian analysis grid' is the > Caret function I asked John to add so we could generate 2D cartesian > grids on a flat surface, and then project the border so it's folded > onto the fiducial surface... it IS a distorted grid (due to the > flattening), but dealing with a triangulated mesh in 2d, or otherwise, > is much more difficult for me to visualize (not that it can't be > done... someday I hope to move towards that...) The subsequent steps > are done in matlab and standard fMRI processing tools, with occasional > use of caret_command to convert to and from surfaces if needed... > > transitioning to the sphere is in development, but of course, it's a > lot harder and we're still working on it... > > -Alex > ~)--------------- > > ---------------------------------------------------------------------- > Alexander Li Cohen > [email protected] (WORK Email) > [email protected] (Non-secure / rapid-response Email) > Petersen/Schlaggar Lab > Medical Scientist Training Program > Washington University in St. Louis School of Medicine > ---------------------------------------------------------------------- > > This message is intended only for the exclusive use of the intended > recipient(s) named herein and may contain information that is > PRIVILEGED and/or > CONFIDENTIAL. If you are not the intended recipient, you are hereby > notified > that any use, dissemination, disclosure or copying of this > communication is > strictly prohibited. If you have received this communication in > error, please > destroy all copies of this message and its attachments and notify us > immediately. > > 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. > > On Jul 9, 2009, at 2:09 PM, Donna Dierker wrote: > > > Hi Long, > > > > Oh, okay. You mean this paper, where Alex detects areal boundaries > > using functional connectivity: > > > > http://dx.doi.org/10.1016/j.neuroimage.2008.01.066 > > > > This is a legitimate use of a flat map, although I think that Alex > > Cohen > > may have figured out a way of using the spherical map, instead. Over > > time, he has simplified this process. Alex is a caret-users > > subscriber, > > but I forward this reply to him, to make sure he sees it. > > > > The activation map for each subject is generated in volume-land. > > The 2D > > image analysis (edge detection, etc.) is better answered by Alex > > directly. > > > > But let me describe one way you could create the seeds: > > > > 1. Load flat map in main Caret window. Load fiducial surface in > > Window 2. > > > > 2. Select Layers: Borders: Create Cartesian Grid Flat borders and > > enter > > the desired spacing. > > > > 3. Select Layers: Borders: Project borders. > > > > 4. Select File: Save Data File: Border Files - Surface: Associated > > surface -- change from Flat to Fiducial. > > > > The resulting border file can be opened in a text editor and/or read > > in > > by a program like Matlab. It contains a bunch of border points that > > represent this grid on the flat map projected onto the fiducial -- > > i.e., > > the grid all crumpled up the way the cortex actually is. Like I said, > > it is possible Alex is doing this on the PALS_B12 sphere now (using > > fiducial surfaces that have been resampled to the standard mesh, but > > still look pretty much identical to the native mesh ones in geometry). > > > > At any rate, there is no need to capture the flat map as an image, nor > > any involvement with the Brodmann parcellation whatsoever. On the > > contrary, if you do what Alex does, it is probably INSTEAD OF Brodmann > > areas (although it would be fun to compare). > > > > Donna > > > > On 07/09/2009 09:35 AM, Long wrote: > >> Dear Donna, > >> > >> Thank you for your quickly reply. My main purpose is to analyze the > >> cerebral cortex by using fMRI data in 2D way. Just like your group > >> did > >> in paper: Defining functional areas in individual human brains using > >> resting functional connectivity MRI. Neuroimage. 2008. How to create > >> seeds and after calculating, how to create a 'activation map' on a > >> flatten cortex and perform the 2D image analysis. > >> > >> Thanks for your help. > >> Long > >> > >> On Thu, Jul 9, 2009 at 3:05 PM, Donna Dierker > >> <[email protected] <mailto:[email protected]>> wrote: > >> > >> On 07/09/2009 06:30 AM, Long wrote: > >> > >> Dear caret-users, > >> > >> I want to analyze the flatten image as a 2D image, so there > >> are a series of questions about this: > >> > >> 1) How to export a flatten cortex as a 2D image? So I can use > >> some 2D image processing methods. > >> > >> I might misunderstand you, but I think it is as simple as > >> displaying the flat map in the main Caret window and doing File: > >> Capture Image of Window. > >> > >> > >> 2) If a cortex was flattened, how to use the new reference > >> coordinate system in 2D cortex to identify the 3D coordinates, > >> e.g., MNI coordinates? > >> > >> In Caret, one typically would have a single topology file for all > >> "CLOSED" surface configurations (e.g., fiducial/midthickness; > >> inflated; spherical), and a CUT topology file for any flat ones. > >> The topology files store the neighbor relationships between the > >> nodes, so you can see why a flat surface, which has cuts, would > >> differ in its neighbors from a surface with no cuts, like the > >> midthickness. But each of these different configurations -- > >> fiducial, inflated, spherical, flat -- has its own coordinate > >> (.coord) file. By default, Caret writes these coord files as > >> binary; however, you can change the default to write them as > >> ASCII, so you can read in the coords into Matlab or whatever > >> software you like. > >> > >> If written in ASCII, the coord file will always have the node > >> number in the first column, so you can grep or join the 2D (flat > >> coord) and 3D (fiducial coord) files by the node number. See > >> > http://brainvis.wustl.edu/CaretHelpAccount/caret5_help/file_formats/file_formats.html#coordFile > >> for more information about the coord file format. > >> > >> What is the relationship between 2D and 3D cortex. > >> > >> It is not a simple one, like an equation. Besides 2D having cuts > >> (broken neighbor relationships), the nodes have been projected > >> onto a Z=0 plane and then morphed across five cycles to reduce > >> distortion and crossovers. But the node correspondence remains > >> the same across configurations. > >> > >> It seems like you might want to do something like this: > >> > >> 1. click on the 2D image > >> 2. find the closest node on the 2D coord > >> 3. lookup up the corresponding 3D coordinate in the fiducial coord > >> > >> This is easy in Caret, and if you have flat surface in main > >> window, fiducial in window 2, Caret will print the fiducial 3D > >> coordinate in the ID window whenever you click on a node in the > >> flat surface (main window). > >> > >> But once you export the flat to a 2D image, rather than remain in > >> Caret, which is node-aware, you will have trouble getting from > >> step 1 to step 2 above. > >> > >> > >> 3) How to export one or two flatten Brodmann areas based on > >> the Brodmann template as a 2D image? > >> > >> This requires registering your individual subjects to the PALS_B12 > >> atlas, so you can deform the atlas Brodmann paint file to your > >> subjects' flat maps. Alternatively, you can deform any measure of > >> interest from your subjects to the PALS_B12 atlas, and look at the > >> Brodmann regions on the atlas flat map, which has a standard > >> shape/outline (see attached capture). > >> > >> Be aware of distortions in the flat maps -- compression near the > >> center, expansion at the edges. We tend NOT to use them for > >> measurement/statistical purposes; rather, they are handy for > >> drawing borders and displaying an image of the entire cortex in > >> one view. I wonder how you will be using them. > >> > >> > >> Thanks for your help. > >> Long > >> > >> ------------------------------------------------------------------------ > >> > >> _______________________________________________ > >> caret-users mailing list > >> [email protected] > >> <mailto:[email protected]> > >> http://brainvis.wustl.edu/mailman/listinfo/caret-users > >> > >> > >> > >> > >> _______________________________________________ > >> caret-users mailing list > >> [email protected] <mailto: > [email protected] > >> > > >> http://brainvis.wustl.edu/mailman/listinfo/caret-users > >> > >> > >> ------------------------------------------------------------------------ > >> > >> _______________________________________________ > >> caret-users mailing list > >> [email protected] > >> http://brainvis.wustl.edu/mailman/listinfo/caret-users > >> > > > > _______________________________________________ > > caret-users mailing list > > [email protected] > > http://brainvis.wustl.edu/mailman/listinfo/caret-users > > _______________________________________________ > caret-users mailing list > [email protected] > http://brainvis.wustl.edu/mailman/listinfo/caret-users >
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