Hey!

I try to replace the fractional anisotropy (FA) value by a more elaborate value considering two and more fiber populations in one voxel. The aim is to use it for a learning study at my institute instead of FA.
There are several such values available but I wonder if any of you actually knows about a (best longitudinal) study where one of these "new" values is actually used for quantification? I only find methodical publications.

Cheers!

Hi Paul,

Some of the methods papers also include example clinical applications, e.g. this one has a section on "[apparent fibre density] AFD voxel-based analysis of Motor Neurone Disease"
  http://dx.doi.org/10.1016/j.neuroimage.2011.10.045

This paper uses generalized fiber anisotropy (GFA) to study genetic influences and IQ:
  http://www.ncbi.nlm.nih.gov/pubmed/18979850

This paper, if I have understood it correctly from a quick glance, uses standard FA, but computes it for each of two fitted tensors, and studies first-episode schizophrenia:
  http://dx.doi.org/10.1016/j.mri.2010.10.005

I'm afraid I don't know of any longitudinal work yet, but I believe a couple of groups have some planned...

Best wishes,
Ged

I suggest to first compute a fully parameterized model of the fiber populations in each voxel,
and then to use appropriate per-fiber measures, such as the FA of a fiber.

This is a link to our 2012 paper on how to do it (Scherrer, Warfield PLOS One 2012):
http://www.plosone.org/article/info%3Ado...

and our 2013 MICCAI paper on what to do if you only have a single shell HARDI (Taquet, Scherrer et al. MICCAI 2013):
http://link.springer.com/chapter/10.1007...