Hi, 

I think you are right. Indeed, as one can see from the coronal average intensity projection, there are planes which are brighter than others (see annexed png). However, I couldn't solve this with destripe. It seems to make the bright slices less different from the others but you can still see them in the projection image and the artifact still stays after the registration. I tried to play around with kernal-fwhm and I've been using the code below. I'll keep trying to tune this, but thank you very much for your reply.