[Insight-users] Spline smoothing distance and N4ITK parameters

[Andriy Fedorov]

Hi,

I am trying to use the N4ITK implementation

http://www.midasjournal.org/browse/publication/640

for intensity inhomogeneity correction in brain MRI images for
longitudinal analysis.

Some of the recent publications emphasize the importance of the proper
selection of the spline distance that controls the smoothness of the
derived field, especially for the higher field imaging:

http://dx.doi.org/10.1016/j.neuroimage.2007.10.026
http://dx.doi.org/10.1016/j.neuroimage.2009.06.039

It seems that N4ITK does not allow to control this spline distance
parameter, at least not directly. I would greatly appreciate if anyone
could confirm or (much better) debunk my observation. I see that it is
possible to set the number of spline control points -- is this
essentially setting the spline distance parameter implicitly?

I am not familiar with all the details of Sled's algorithm, which is
implemented in N4ITK, so I would greatly appreciate any clarification
on how/if the spline distance parameter can be properly controlled.

Thank you

--
Andriy Fedorov, Ph.D.

Research Fellow
Brigham and Women's Hospital
Harvard Medical School
75 Francis Street
Boston, MA 02115 USA
fedorov at bwh.harvard.edu