open-discussion > RE: running interaction with shapeAnalysisMANCOVA
Nov 9, 2015  08:11 PM | Beatriz Paniagua
RE: running interaction with shapeAnalysisMANCOVA
Hi Lara,



Question 1:

shapeAnalysisMANCOVA allows for including variables that ICV correct any measurements, given that you know total brain volume.
(in the wizard, in the test parameters tab, under the "reinterprets the scaling column values etc...") is where you would click tthis option to have your data ICV corrected. For correcting for age you will have to list them as independent variable. For testing diagnosis and sex, probably you could model them using a set of binary variables similar to what we propose here (http://www.insight-journal.org/browse/pu...)
Nominal subject variables such as gender and diagnosis group are
encoded as a set of binary, mutually exclusive variables. In case of considering gender, this would lead to
a 4 binary variable b0 contains 1 if the subject is male and control, and 0 otherwise, b1 contains 1 if the
subject is female and control and 0 otherwise, b2 contains 1 if the subject is male and autistic patient and 0
otherwise, b3 contains 1 if the subject is female and autistic patient and 0 otherwise.

Examples of commandlines are also provided in the aforementioned paper.



Question 2:

I think it would be safe to report significant shape changes, even if the FDR or Bonferroni (especially with Bonferroni, since it is a much more strict correction test) result into small clusters of significance. I would actually look at how those clusters look in the raw P maps as well.



Question 3:

The differences between DiffMagnitude_original attribute and "DiffMagnitude" (range 0-100) are sadly a result of having no maintenance support for the module. The released and discontinued version of SAM that you are using, generates MRML 3DSlicer scenes for visualization of statistical results of this program in Slicer. Slicer back in the years when we developed this (2010) did not have a good visualization scheme for continuous variables (such as structural differences). Slicer allowed though visualizing color labels (that they had capped at 100) so in order to use that infrastructure we had to rescale our continuous variable maps from 0-100. DiffMagnitude is that scaled map. Your real map and the one you want to report results with is DiffMagnitude_original. Sorry about the confusion. We are working on gathering funding for a new shape statistical package and we will keep you posted, as well as have all these bugs in mind for correction.



I hope that helps!
Thanks,


Beatriz

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TitleAuthorDate
Lara Foland-Ross Nov 4, 2015
Lara Foland-Ross Nov 6, 2015
RE: running interaction with shapeAnalysisMANCOVA
Beatriz Paniagua Nov 9, 2015
Lara Foland-Ross Nov 9, 2015
D J Nov 10, 2015
Martin Styner Nov 10, 2015
Lara Foland-Ross Nov 10, 2015
Martin Styner Nov 11, 2015
Lara Foland-Ross Nov 11, 2015
Beatriz Paniagua Nov 12, 2015
Martin Styner Nov 12, 2015
Lara Foland-Ross Nov 17, 2015
Beatriz Paniagua Nov 18, 2015
Lara Foland-Ross Nov 18, 2015
Lara Foland-Ross Nov 23, 2015
Lara Foland-Ross Nov 30, 2015
Beatriz Paniagua Nov 30, 2015
Beatriz Paniagua Dec 1, 2015
Lara Foland-Ross Dec 2, 2015
Beatriz Paniagua Dec 8, 2015
Lara Foland-Ross Nov 9, 2015
D J Nov 9, 2015