Hi Tim,

Using -surface-sphere-project-unproject followed by -metric-resample seems
to have done the trick. Thanks a lot!

Estrid

On Tue, Apr 19, 2016 at 11:50 PM, Timothy Coalson <[email protected]> wrote:

> Ah, right, we don't provide low res registered spheres.  In that case, it
> does make sense to use -surface-sphere-project-unproject to concatenate the
> registration onto a sphere with the correct resolution.  The file names are
> somewhat confusing, but I suspect the considerably more complicated
> filename in fs_L and fs_R is fsaverage (7?) 164k mesh registered to fs_LR,
> and the "fsaverage" in the same directory should be copies of the fsaverage
> standard sphere (not to be confused with the "fsaverage" spheres one
> directory up, which are actually fs_LR, not fsaverage).  There are two ways
> to do this, but it might make more sense to generate the fsaverage5 analog
> of the registered sphere from the fs_L directory.
>
> To do this, use -surface-sphere-project-unproject with fsaverage5 standard
> sphere as input, fsaverage 164k standard sphere as project-to (assuming all
> fsaverage standard spheres are aligned), and fsaverage registered to fs_LR
> sphere as unproject-from.  You can use the resulting sphere with any
> left-hemisphere fs_LR standard sphere to do the resampling (for right
> hemisphere, you'd need to generate the equivalent separately, using the
> fs_R directory).
>
> I don't expect any benefit to upsampling as an intermediate step, if
> anything it should result in slightly more blurring in the end result.  I'm
> not as sure what the effect would be on label files.
>
> As for the cross-hemisphere correspondence, the fact that fs_LR has it,
> while fsaverage does not, means that fs_LR and fsaverage can't simply be
> already in register for both hemispheres - I don't know if they are in
> register for even one of the hemispheres.  Donna was explaining why we
> chose to have this property even though it made it slightly more involved
> to convert to/from fsaverage.
>
> Tim
>
>
> On Tue, Apr 19, 2016 at 2:26 AM, Estrid Jakobsen <[email protected]>
> wrote:
>
>> Hi,
>>
>> Many thanks for the replies!
>>
>> @Donna, thanks for the info. This is certainly good to know, but I wonder
>> how cross-hemisphere registration affects my problem since I'm only using
>> the left hemisphere...?
>>
>> @Tim, I actually don't need the individual subjects' registrations as I
>> just want to register a single group-level map, I just used a spherical
>> mesh from an individual to run the -metric-resample command since I
>> couldn't find a group-level fs_LR sphere (I assumed this wouldn't make a
>> difference, but perhaps I'm wrong?). I specifically need to register to
>> fsaverage5 since I'd like to compare to an independent dataset in this
>> space. Using the atlas-to-atlas registrations you referred to from the
>> pipeline repository, I wonder if it would make sense for me to first
>> upsample from fs_LR_32k using
>> fsaverage.L_LR.spherical_std.164k_fs_LR.surf.gii and then downsample to
>> fsaverage5 from there?
>>
>> Thanks again!
>>
>> Estrid
>>
>> On Mon, Apr 18, 2016 at 11:25 PM, Timothy Coalson <[email protected]> wrote:
>>
>>> The -surface-sphere-project-unproject command is used for concatenating
>>> registrations, and since you want to go from fs_LR to fsaverage, which is a
>>> registration that we compute, concatenating registrations isn't the way to
>>> get there.
>>>
>>> However, I don't know if we release the fsaverage registrations
>>> per-subject (to us, they are an intermediate registration).  We appear to
>>> have atlas-to-atlas registrations available in the pipeline repository,
>>> under global/templates/standard_mesh_atlases, the fs_L and fs_R directories
>>> contain the fsaverage spheres registered to fs_LR as I understand it.
>>>
>>> Do you specifically need to be in fsaverage, or is just a simple
>>> downsampling okay?  We have lower resolutions of fs_LR, for instance 20k,
>>> and you can also create near-arbitrary resolution spheres if you want more
>>> control over downsampling.  For some analyses, parcellation could be more
>>> appropriate than downsampling.
>>>
>>> It should be noted that using the individual subjects fsaverage
>>> registration would discard the registration improvements made by MSM (for
>>> MSMsulc, mainly less distortion).  If an atlas-to-atlas registration is
>>> used, then the registration improvements may be retained (alignment
>>> improvements will be retained, distortion will depend on the method used
>>> for atlas to atlas registration), but of course will give a different
>>> result than actually using freesurfer's registration.
>>>
>>> Tim
>>>
>>>
>>> On Mon, Apr 18, 2016 at 9:44 AM, Donna Dierker <[email protected]
>>> > wrote:
>>>
>>>> Hi Estrid,
>>>>
>>>> Help from others is likely to be needed, but I can help a little.
>>>>
>>>> The HCP surfaces get to 32k_fs_LR mesh via the Freesurfer registration
>>>> (?h.sphere.reg); however, the fs_LR mesh is not the same as the fsaverage
>>>> mesh, even though it is based on it.  The fsaverage left and right
>>>> hemispheres are not in registration with one another.  Vertex i in the left
>>>> hem could be in the occipital lobe, while it could be in the frontal lobe
>>>> in the right hem.  The fs_LR mesh is in register across hemispheres --
>>>> vertices in left and right hems are in as close to the same place as
>>>> registration could get them to be.  This facilitates cross-hem analyses.
>>>>
>>>> There is a relevant script here:
>>>>
>>>>
>>>> https://github.com/Washington-University/Pipelines/blob/master/PostFreeSurfer/scripts/FreeSurfer2CaretConvertAndRegisterNonlinear.sh
>>>>
>>>> Specifically this line i sthe one to be studied:
>>>>
>>>> > #Concatenate FS registration to FS --> FS_LR registration
>>>> > ${CARET7DIR}/wb_command -surface-sphere-project-unproject
>>>> "$AtlasSpaceFolder"/"$NativeFolder"/"$Subject"."$Hemisphere".sphere.reg.native.surf.gii
>>>> "$AtlasSpaceFolder"/fsaverage/"$Subject"."$Hemisphere".sphere."$HighResMesh"k_fs_"$Hemisphere".surf.gii
>>>> "$AtlasSpaceFolder"/fsaverage/"$Subject"."$Hemisphere".def_sphere."$HighResMesh"k_fs_"$Hemisphere".surf.gii
>>>> "$AtlasSpaceFolder"/"$NativeFolder"/"$Subject"."$Hemisphere".sphere.reg.reg_LR.native.surf.gii
>>>>
>>>> If you're like me, it will take a few days for you to get your head
>>>> around it.
>>>>
>>>> But I think something like this -- projecting to one standard surface
>>>> and unprojecting from another -- will be the answer.  It might take
>>>> multiple hops to get there, but probably only until you get the magic
>>>> spheres you need to make this work.
>>>>
>>>> I still struggle with understanding the distinction between meshes
>>>> whose vertices are in correspondence, and ones that have differing numbers
>>>> of vertices, but a spatially aligned with one another.
>>>>
>>>> Donna
>>>>
>>>>
>>>> On Apr 18, 2016, at 8:47 AM, Estrid Jakobsen <[email protected]>
>>>> wrote:
>>>>
>>>> > Dear experts,
>>>> >
>>>> > I'm trying to use wb_command -metric-resample to downsample a vector
>>>> of data points from fs_LR_32k (32492x1) to fsaverage5 (10242x1) space.
>>>> >
>>>> > If I'm not mistaken, this should be possible without prior
>>>> registration, because the HCP fs_LR_32k surfaces and the fsaverage5 surface
>>>> should already be in register. I've saved my data vector as a metric gifti
>>>> file (data.func.gii) in matlab by loading a pre-existing .gii file using
>>>> the gifti toolbox and replacing gifti.cdata with my own data vector. I'm
>>>> then running the following command:
>>>> >
>>>> > wb_command -metric-resample data.func.gii
>>>> 100307.L.sphere.32k_fs_LR.surf.gii fsa5.lh.sphere.surf.gii ADAP_BARY_AREA
>>>> data_fsa5.func.gii -area-surfs 100307.L.inflated.32k_fs_LR.surf.gii
>>>> fsa5_lh.inflated.surf.gii -current-roi mask.func.gii -valid-roi-out
>>>> roi_out.func.gii
>>>> >
>>>> > The command runs without errors, but the output looks strange (see
>>>> attachment). It seems as though the neighborhood information is preserved
>>>> but the coordinates are not, especially obvious by the medial wall mask
>>>> being shifted anterior. I've tried running the command with and without the
>>>> -area-surfs and -current-roi (to mask out the medial wall) options, neither
>>>> of which seem to make any difference.
>>>> >
>>>> > Any suggestions as to what might be going wrong here would be very
>>>> much appreciated.
>>>> > Thanks!
>>>> >
>>>> > Estrid
>>>> >
>>>> > ****************
>>>> > Estrid Jakobsen
>>>> > PhD Student, IMPRS NeuroCom
>>>> > Department of Neurophysics
>>>> > Max Planck Research Group Neuroanatomy and Connectivity
>>>> > Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig
>>>> > +49 341 9940-2423
>>>> > _______________________________________________
>>>> > HCP-Users mailing list
>>>> > [email protected]
>>>> > http://lists.humanconnectome.org/mailman/listinfo/hcp-users
>>>> >
>>>> > <groupconn45_fsa5.png>
>>>>
>>>>
>>>> _______________________________________________
>>>> HCP-Users mailing list
>>>> [email protected]
>>>> http://lists.humanconnectome.org/mailman/listinfo/hcp-users
>>>>
>>>
>>>
>>
>>
>> --
>> ****************
>> Estrid Jakobsen
>> PhD Student, IMPRS NeuroCom
>> Department of Neurophysics
>> Max Planck Research Group Neuroanatomy and Connectivity
>> Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig
>> +49 341 9940-2423
>>
>
>


-- 
****************
Estrid Jakobsen
PhD Student, IMPRS NeuroCom
Department of Neurophysics
Max Planck Research Group Neuroanatomy and Connectivity
Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig
+49 341 9940-2423

_______________________________________________
HCP-Users mailing list
[email protected]
http://lists.humanconnectome.org/mailman/listinfo/hcp-users

Reply via email to