Maria,
> I have performed preprocessing of MRI images of 70 patients with
> autoimmune disease and 70 healthy control subjects by applying the VBM8
> extension to SPM8, the preprocessing were done with default settings. To
> my surprise, WM was (non-significantly) increasing with increasing age,
> from literature I would expected the effect of age to be negative. When
> plotting WM volume against age, it seems like WM is increasing up to
> approximately 50 years, and afterwards decreasing with increasing age.
from the literature I have read on white matter development in the early
years, the trend you see does not seem implausible. I think it would be
important to know, though, what images exactly you looked at, and
whether they were modulated, modulated for the non-linear part only (a
vbm specialty ;), non-modulated etc.
> Our MRI images are 10 years old, so the findings could be due to low
> resolution and misregistration of WM/GM/CSF, but I would like to hear if
> anyone has the same findings or could recommend some literature on the
> topic. The age distribution of our cohorts is 27-87 years, mean 57
> years, almost 90 % are female.
Spatial resolution of course can't be helped, but otherwise, it is more
important that the analyses methods are current than that the data is ;)
One issue with the literature is that volume is so old-fashioned and
that most recent papers have used diffusion MRI to investigate white
matter. However, a search for "white matter development mri lifespan" in
PubMed would seem to give you at least a couple of starting points.
Cheers,
Marko
PS: I also agree with everything Harald just wrote :)
--
____________________________________________________
PD Dr. med. Marko Wilke
Facharzt für Kinder- und Jugendmedizin
Leiter, Experimentelle Pädiatrische Neurobildgebung
Universitäts-Kinderklinik
Abt. III (Neuropädiatrie)
Marko Wilke, MD, PhD
Pediatrician
Head, Experimental Pediatric Neuroimaging
University Children's Hospital
Dept. III (Pediatric Neurology)
Hoppe-Seyler-Str. 1
D - 72076 Tübingen, Germany
Tel. +49 7071 29-83416
Fax +49 7071 29-5473
[log in to unmask]
http://www.medizin.uni-tuebingen.de/kinder/epn/
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