Hello Emilie, 

Yes the b values vary around 0, 1000, and 2000 because they account for the imaging gradient. I thought it would be better to include this in the model, but would I be better to just use 0, 1000 and 2000? 

Sorry for the potentially silly questions, but is there a way to test the model fit? Like a goodness-of-fit measure? 


Thank you, 

Meg