I can't say whether it's the best way, but it should be relatively unbiased

On Tue, 5 Jul 2011, Ignacio Letelier wrote:

Then, and finally is this method the best way to determine whether exist any cortical thickness anomaly, I mean, to use a normal  control acquisition as comparisson?

Thanks in advance Ignacio. 2011/7/5 Bruce Fischl fischl@nmr.mgh.harvard.edu Hi Ignacio,

  the thickness is definitely affected by factors such as sequence
  type, field strength and acquisition parameters (not to mention
  age, maybe gender, etc...) so I think you need to acquire your
  own control(s) on a matched acquisition.

  cheers.
  Bruce

On Tue, 5 Jul 2011, Ignacio Letelier wrote:

  Hi Bruce,

  Otherwise, is it possible to simply compare my T1 brain
  acquisition  (with
  dysplasia suspicion) with a 'normal template' (which maybe
  bert) to
  determine whether there exist any  anomaly in the cortical
  thickness ? and,
  is it possible to visualize these potential differences
  using a color map
  scaling?

  Thanks in advance-

  Best regards.

  Ignacio.

  2011/7/3 Bruce Fischl <fischl@nmr.mgh.harvard.edu>
       Hi Ignacio,

       I see. You could do that, but I don't think it will
  show what
       you want. There is a big geometric component to the
  thickness -
       crowns are thick and fund are thin - so at the very
  least you
       might try including mean curvature as a covariate.


  cheers
  Bruce

  On Fri, 1 Jul 2011, Ignacio Letelier wrote:

       Sorry I didn't realize since you have the same
  domain.

       Ok, Let's say I do know the mean cortical thickness
  value
       of a subject. Then
       is it possible know  what brain areas differ more
  from
       that mean value by
       using a color map visualization (I.e.  for example:
  red =
       higher deviations,
       deep blue = lower deviations)? So this way I can
  determine
       where there may
       exist some kind of dysplasia.

       Best regards.

       2011/7/1 Bruce Fischl <fischl@nmr.mgh.harvard.edu>
            can you post this kind of thing so others can
  answer?
       I still
            don't understand though. stdv of what?


       On Fri, 1 Jul 2011, Ignacio Letelier wrote:

            Let's say I want to know if there is a way to
  know
       where
            is the highest stdv in the same subject, using a
       color map
            visualization in qdec or something?

            Best regards.

            2011/7/1 Bruce Fischl
  <fischl@nmr.mgh.harvard.edu>
                 Hi Ignacio

                 you mean different from the median in that
       subject?
            Easy enough to do in matlab, but we don't have
       anything
            out of the box to do it

                 cheers
                 Bruce

            On Fri, 1 Jul 2011, Ignacio Letelier wrote:

                 Hi forum

                 Is it possible to get statistical maps of 
       cortical
            thickness differences in the same subject? I.e.
  to
       know
            what areas differ most from the median


                 --
                 Ignacio




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