I'm interested in getting CSF maps in native space by segmenting T1-weighted
images with good contrast. The CSF maps show the CSF boundaries but the
ventricles as well as the larger sulcal spaces have no signal inside them.
The results were the same even I when I increased the bias regularisation.
Smoothing the scans a bit (3x3x3 kernel) made the boundaries thicker but the
ventricles were still empty. It's as though the CSF was mistaken for
background. Are there any other defaults I should try changing?
Ironically, I had no such problem with lesser quality scans in which the
contrast was not as good.
Your help is much appreciated.
Francois
|