Hi Ralph,
As John said, the default segmentation does not model lesions (i.e.
there is no extra class to model explicitly abnormal tissue)... You
could however try to include an additional class (i.e. an "extra" prior
map in your segmentation) that can be improved iteratively. This "extra"
class would model any tissue that is unexpected (e.g. not a normal GM
WM, or CSF).
For more details, see this paper:
http://dx.doi.org/10.1016/j.neuroimage.2008.03.028
I hope this helps,
Mohamed
jmanjon wrote:
> Dear Ralph and John,
>
> I remember that a similar problem was solved recently using lesion
> impainting.
>
> the reference is this one:
>
> "Michael Sdika and Daniel Pelletier. Nonrigid Registration of Multiple
> Sclerosis Brain Images Using Lesion Inpainting for Morphometry or
> Lesion Mapping.
> Human Brain Mapping 30:1060–1067 (2009)"
>
> hope this helps
>
> Jose Manjon
>
>
>
> John Ashburner escribió:
>> The segmentation routines in SPM does not model lesions, although the
>> literature is full of examples of segmentation algorithms that do.
>> These are probably of no use to you though.
>>
>> Best regards,
>> -John
>>
>> On Fri, 2010-01-08 at 09:08 +0100, Buchert, Ralph wrote:
>>
>>> Dear all,
>>>
>>>
>>>
>>> in patients with lesions, the 6 tissue segmentation sometimes
>>> classifies large parts of the lesion as gray matter (s example below).
>>> How could one avoid this? I would very much appreciate your help.
>>>
>>>
>>>
>>> With very best wishes,
>>>
>>>
>>>
>>> Ralph.
>>>
>>>
>>>
>>> --------------------------------------------------------------------
>>>
>>> Dr. Ralph Buchert
>>>
>>> Charité - Universitätsmedizin Berlin
>>>
>>> Campus Charité Mitte
>>>
>>> Klinik für Nuklearmedizin
>>>
>>> Charitéplatz 1
>>>
>>> 10117 Berlin
>>>
>>> Tel: +49 30 450 527 059
>>>
>>> Fax: +49 30 450 527 932
>>>
>>> Email: [log in to unmask]
>>>
>>> --------------------------------------------------------------------
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
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>
>
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