"this is now where our development effort is focused these days" should have 
read "this is NOT where our development effort is focused these days"

On Oct 25, 2011, at 9:33 AM, Donna Dierker wrote:

> Sorry I don't have time to read this more carefully, but I'm swamped this 
> week.
> 
> But the quick scan leads me to believe this is an issue with you trying to 
> segment monkey data at a resolution above 0.5mm.
> 
> The problem is that some of the routines (e.g., especially 
> eye/skull/hindbrain removal) depend on the number of slices away from the AC 
> something is.  If the number of slices is twice what it expects, it won't 
> work.  You can turn off eye/skull removal, but as you already know, 
> de-checking hindbrain just makes it fail.
> 
> Caret's segmentation has its limits, and this is now where our development 
> effort is focused these days.  Sorry.
> 
> I know some people have gotten Freesurfer to segment monkey data, but I 
> suspect there are tricks/tweaks, and I do not know them.  I don't know how 
> the talairach.xfm stuff (and that which depends on it) works, for example.  
> Obviously MNI305 won't work as a target.
> 
> 
> On Oct 25, 2011, at 7:54 AM, wolf zinke wrote:
> 
>> Hi,
>> 
>> I had a similiar question a while ago, that was related to your issues. At 
>> this time there was no 64 bit version of caret available, and hence I ran 
>> into memory troubles with a high resolution monkey file (do you use the 64 
>> bit version of caret?).
>> 
>> However, Donna Dierker gave me some pointers, why it would be problematic to 
>> use a voxel size different from 0.5 mm. I am not sure, if this is still 
>> true, but that might be a reason for your problem. I myself had also the 
>> impression, that for the segmentation a resolution of 0.25 mm would be very 
>> beneficial.
>> 
>> I hope that this information helps,
>> wolf
>> 
>>> Hi, 
>>> 
>>> Thanks for the clarification. Currently,I am running caret on the 0.5 mm 
>>> resolution and it overall gives good results, but fails in occipital 
>>> regions. However, with your information I have a good reason to stick to 
>>> the 0.5 mm resolution - makes the manual correction faster anyway. 
>>> 
>>> thanks for the reply, 
>>> wolf 
>>> 
>>> 
>>> 
>>> On 01/28/2010 04:03 PM, Donna Dierker wrote: 
>>> Setting aside the memory/64-bit question, there are assumptions built into 
>>> the SureFit algorithm that assume voxdims for monkeys around 0.5-0.75mm 
>>> cubed.  For example, there are routines in the hindbrain removal that are 
>>> based on number of *slices* from the AC, and if you double the resolution, 
>>> those will be off by a factor of two.  In short, it will fail. 
>>> 
>>> Try downsampling to 0.5 and making sure you crop to left and right hems.  
>>> If the problems persist, upload your anatomical volume here: 
>>> 
>>> http://pulvinar.wustl.edu/cgi-bin/upload.cgi 
>>> 
>>> On 01/28/2010 07:30 AM, wolf zinke wrote: 
>>>> Hi, 
>>>> 
>>>> Sorry that I did not reply directly to this thread, but I did not find any 
>>>> option for this reply. 
>>>> 
>>>> Is there a reason why caret is not build for 64 bit systems? I tried to 
>>>> run a segmentation on macaque data with 0.25 mm voxel size, hoping to get 
>>>> better results due to the resoltion. However, Caret threw an error about 
>>>> insufficient memory, which first puzzled me since the PC got 32GB. But 
>>>> than I realized that due to the 32 bit, Caret is not able to address more 
>>>> than 4GB of the RAM, right? 
>>>> 
>>>> cheers, 
>>>> wolf 
>> 
>> 
>> On 25/10/11 08:30, Colin Reveley wrote:
>>> I wonder if the bits of spine and the affine to to (deskulled, upsampled) 
>>> F99 are an issue.
>>> 
>>> I don't recall, but it's hugely likely I tried with rigid body too, i.e. 
>>> without the bit cut off at bottom. 
>>> 
>>> On 25 October 2011 00:53, Colin Reveley <[email protected]> wrote:
>>> 
>>> Hello.
>>> 
>>> I have macaque data that is 0.25mm. I like that. I can do things with it 
>>> that are more than cosmetic.
>>> 
>>> The data was taken with a fancy brukker, and the contrast is very good from 
>>> the sequence used. so good I wonder if it's a problem (it's a FLASH_MTR - 
>>> it does correlate to T1 really closely, but contrast GM-WM is clearer. and 
>>> there may be differences.)
>>> 
>>> Thus far, I've been downsampling to 0.5 to make CARET surfaces.
>>> 
>>> I'm beginning to suspect that, for my project, there is profit in a surface 
>>> made at 0.25, with many nodes.
>>> 
>>> what I am interested in is the really quite small region (in absolute 
>>> terms) that was the subject of the paper by lewis and van essen in 2000.
>>> 
>>> even though the F99 atlas does not have 300,000 nodes the paint, border and 
>>> metric data are scalable and my own data would indeed support a hi-res 
>>> surface, and benefit from it.
>>> 
>>> I've got RAM. 
>>> 
>>> but I never managed to get far with 0.25.
>>> 
>>> segmentation fails with hindbrain at any resolution below 0.5.
>>> 
>>> I didn't mind. But now I think (I really do) I have a good reason to seek 
>>> surface construction directly from my structural data at 0.25mm.
>>> 
>>> So: is it possible? caret_command ... -res=X ?
>>> 
>>> my data is ex-vivo. And probably no more than 1% of nonGM or nonWM voxels 
>>> are nonzero. no ventricles. nothing. I did that. A mistake maybe.
>>> 
>>> If I segment at 0.5, upsample to 0.25 and generate a surface with my data 
>>> it works. CARET can make the surface.
>>> 
>>> but segmentation does not work.
>>> 
>>> appreciate help.
>>> 
>>> Colin
>>> 
>>> 
>>> _______________________________________________
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>>> 
>>> [email protected]
>>> http://brainvis.wustl.edu/mailman/listinfo/caret-users
>> 
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