For larger changes over time you can use the mean of all time points to derive the deformations.
Christian
On Tue, 6 Dec 2011 09:04:00 -0500, Jeff Browndyke <[log in to unmask]> wrote:
>Thanks. Are you recommending baseline versus follow-up as the basis for deformation application because the assumption is that WMH increase over time? What if I have three time points? Would it be preferable in terms of bias to use the middle time point for the deformation application?
>
>Jeff
>
>On Dec 6, 2011, at 8:54 AM, Christian Gaser wrote:
>
>> Dear Jeff,
>>
>> the lesion toolbox cannot be implemented in the longitudinal pipeline, thus I would recommend to simply use the following approach:
>> 1. Segment data with VBM8 and Lesion toolbox and write segmentations in raw space. Save forward deformations for the baseline scan (also use Dartel normalization)
>> 2. Register raw segmentation for each subject separately (only estimate parameters).
>> 3. Apply deformation of baseline scan to all scans.
>>
>> Regards,
>>
>> Christian
>>
>> On Tue, 6 Dec 2011 08:41:37 -0500, Jeff Browndyke <[log in to unmask]> wrote:
>>
>>> This is exciting news! Thank you, Christian, for the soon-to-be-released tool.
>>>
>>> How does the tool handle longitudinal FLAIR data? Any integration with the VBM8 longitudinal processing tools? I have serial FLAIR/MPRAGE that I would love to assess for WMH volume increase, but recognize that any segmentation process must take image bias changes into account...but I'm not certain if the current VBM8 longitudinal routines are appropriate for FLAIR.
>>>
>>> Thanks again,
>>> Jeff
>>>
>>> -----------------------------------------------------------------------
>>> Jeff Browndyke, Ph.D.
>>> Clinical & Research Neuropsychologist
>>> Durham VA & Duke University Medical Centers
>>>
>>> [log in to unmask] / [log in to unmask]
>>> office: (919) 286-0411 ext. 4656
>>> cell: (336) 264-4222
>>>
>>>
>>> On Dec 6, 2011, at 6:57 AM, Christian Gaser wrote:
>>>
>>>> I have forgotten to post the link to the paper:
>>>> http://dbm.neuro.uni-jena.de/pdf-files/Schmidt-NI11.pdf
>>>>
>>>> On Mon, 5 Dec 2011 11:22:51 -0200, Alfredo Damasceno <[log in to unmask]> wrote:
>>>>
>>>>>
>>>>> Dear VBM experts,
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> I am studying multiple sclerosis brain atrophy and would like to know if there is a segmentation tool in VBM8 that allow me to mask patients white matter lesions in order to exclude them from the segmentation process. I know there is one such tool for spm5 (spm_segment), but is there any available for vbm8?
>>>>>
>>>>>
>>>>> Many thanks
>>>>>
>>>>>
>>>>> Alfredo Damasceno
>
>-----------------------------------------------------------------------
>Jeff Browndyke, Ph.D.
>Clinical & Research Neuropsychologist
>Durham VA & Duke University Medical Centers
>
>[log in to unmask] / [log in to unmask]
>office: (919) 286-0411 ext. 4656
>cell: (336) 264-4222
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