I’m hoping for some more general thoughts (not MRtrix specific). I am helping to set up a study and we are intending to collect a multiband multishell acquisition (b=0,500,1000,2000) at 2x2x2mm. What we are finding is that the acquisition is ok at b=0 but increasingly noisy as shell values. I know that noise is expected but the amount of noise is hard for me to wrap my head around. Any thoughts on what might be causing this? Any MRtrix that might help me track down whether there is some aspect of the protocol that is causing this.
Thanks in advance for any thoughts.
Note: All acquisitions to date are on Siemens systems and the noise in the screenshots below is representative of acquisitions on ACR phantoms and people and multiple sites. Note also that the non-b0 images have had the intensity rescaled manually in ITKSnap just to make anything visible (particularly the b=2000)