If you're using version 5.2, you don't have to set nb0. Version 5.1 assumed that there were nb0 images acquired with b=0 in the very beggining of the DWI series, but 5.2 doesn't make that assumption.
On Tue, 2 Apr 2013, stdp82@virgilio.it wrote:
Hi Anastasia, my subjects have gradient=0 only in first or last line.
I'm noting that the subjects having 0.000 0.000 0.000 in the first line of bvecs.txt (0 in vals.txt) show correct tracts.
The subjects that having 0.000 0.000 0.000 as last line of bvecs.txt show wrong or lacking tracts.
For these subjects, I have already checked registration and gradients.
Is possible that this issue depends from setting of nb0.
In both cases (first or last line with 0.000) I have used set nb0 = 1. Is this correct?
Thank you very much,
Stefano