No need to build it yourself. The binary is fine. The current source just has 
more features.


The issue is the fiber radius. If you leave it at 0 (default value), then the 
fiber radius is estimated based on the number of fibers in the "fullest" voxel. 
If you set it manually, in this case 3µm, you won't see anything if there are 
not enough fibers in the voxel. So, either you generate much more fibers to 
increase the fiber density, or you set the fiber radius to 0 for automatic 
estimation. This should fix your issue. Let me know if it works!


Peter



________________________________
Von: Patricio Donnelly Kehoe <[email protected]>
Gesendet: Montag, 23. Januar 2017 14:50
An: Neher, Peter
Cc: [email protected]
Betreff: Re: [mitk-users] [Fiberfox] Low range of values in generated Nifti 
using Fiberfox

Hello Peter, I'm using the binaries in Ubuntu 14.04. The acquisition parameters 
are the default ones:

Signal Scale: 100
TE: 100
Line Readout Time: 0.84
Time homogeneity relaxation: 50
Fiber Radious: 3

Values range are very limited (only one value between fiber voxels and nonfiber 
voxels) in B0 and non B0 images. For each the ranges are:

B0
Nonfiber voxel: 189
Fiber Voxel: 190

Non B0
Nonfiber voxel: 70
Fiber Voxel: 71

Do I have to compile from source?

Thanks,
Patricio


2017-01-23 6:21 GMT-03:00 Neher, Peter 
<[email protected]<mailto:[email protected]>>:
Hi Patricio,

you are talking about b0 intensities, right? 70 seems pretty low in general. 
What is your signal scale parameter? Maybe you set that to a value one order of 
magnitude higher.

Your model parameters seem fine. In general, the shorter the echo time, the 
lower the contrast because there is not enough time for the signal to decay. 
How long is your echo time?

Are you using the MITK Diffusion installer or did you build it yourself?

Cheers,
Peter

Von: Patricio Donnelly Kehoe 
[mailto:[email protected]<mailto:[email protected]>]
Gesendet: Freitag, 20. Januar 2017 20:48
An: [email protected]<mailto:[email protected]>
Betreff: [mitk-users] [Fiberfox] Low range of values in generated Nifti using 
Fiberfox

Hello, I'm using Fiberfox to generate very simple fiber geometries and I keep 
getting Nifti files with very low range of intensities between fiber and non 
fiber voxels. I want to know if I'm doing anything wrong or if this behavior is 
expected.
I have been playing around with the model values, but I can't get a big range 
of intensity values. For example, the difference between fiber and non fiber 
voxels is only one unit of intensity values (71 and 70).
Maybe I'm configuring badly the parameters in the model configuration between 
intra-axonal, extra-axonal and extra-axonal compartments.
Intra-axonal values are:
T2-relaxation: 110 ; FA: 0.97
Inter-axonal values:
T2-relaxation: 110 ; FA: 0.97
Extra-axonal values (Ball-model):
T2-relaxation: 80
If needed I can provide more information.
Thanks,

--
Bioengineer Patricio Donnelly Kehoe
PhD Student at CIFASIS - CONICET
Multimedia Signal Processing Group - Neuroimage Division
http://www.cifasis-conicet.gov.ar/
Contact Number: +5493412164799




--
Bioing. Patricio Donnelly Kehoe
PhD Student at CIFASIS - CONICET
Multimedia Signal Processing Group - Neuroimage Division
http://www.cifasis-conicet.gov.ar/
Contact Number: +5493412164799


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