> Hi,
>
> The Bayesian framework and Markov Random Field are part of
> the segmentation method - FAST - which you can read about in:
> Y. Zhang, M. Brady, and S. Smith.
> Segmentation of brain MR images through a hidden Markov random
> field model and the expectation maximization algorithm.
> IEEE Trans. on Medical Imaging, 20(1):45-57, 2001.
> this is linked from the "FAST Research Page" which you
> can find from the FAST online documentation.
>
> If you read the SIENA technical report at:
>
http://www.fmrib.ox.ac.uk/analysis/research/siena/siena.pdf
> then you can see in equation 2 and the discussion
> afterwards that the true area, A, and volume, V, are not
> needed, but instead the ratio, f, is found by a calibration
> process that involves scaling a known image, which then
> allows the %BVC to be calculated from the edge motion, l,
> which is defined in equation 1.
>
> I hope this helps.
> All the best,
> Mark
>
>
>
> On 21 Jul 2010, at 06:42, Michele Placci wrote:
>
>> Dear Prof. Smith,
>>
>> thank you for your fast reply.
>>
>> For example in your article "Brain atrophy analysis using single and
>> multiple time point data" in the section
>> 2.5 change analysis you talk about: bayesian framework and hidden
>> markov random field.
>> Can you tell me please where and how do you applied them?
>>
>> In the section 2.6 Percentage brain volume change quantification,
>> you used A (actual brain area) and V (actual brain
>> volume), but how do you calculated them?
>>
>> Thank you in advance.
>>
>>
>>
>>
>> 2010/7/21 Stephen Smith <
[log in to unmask]>
>> Hi - there isn't really any "maths" as such that is particularly
>> interesting I think - SIENA is just a set of heuristic algorithms
>> tuned for a specific application. Though you might be referring to
>> a lower-level - for example the maths underneath BET or FAST - in
>> which case those relevant papers have more information?
>>
>> Cheers.
>>
>>
>>
>> On 21 Jul 2010, at 10:56, Michele Placci wrote:
>>
>>> Dear experts, can you tell me please if there is some publications
>>> that talk about the MATHEMATHICS underlying the calculation of
>>> volumes, such as adopted by SIENA?
>>>
>>> I read the article "Brain atrophy analysis using single and
>>> multiple time point data" Stephen M. Smith et al
>>> but I'd like to know more details.
>>>
>>> Can you help me please?
>>> Thank you.
>>
>>
>> ---------------------------------------------------------------------------
>> Stephen M. Smith, Professor of Biomedical Engineering
>> Associate Director, Oxford University FMRIB Centre
>>
>> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
>> +44 (0) 1865 222726 (fax 222717)
>>
[log in to unmask] http://www.fmrib.ox.ac.uk/~steve
>> ---------------------------------------------------------------------------
>>
>>
>>
>>
>