This is really not correct. External fields are tiny relative to these fields, you have bigger issues with coupling and eddy currents. It’s not quite as simpl

This is really not correct. External fields are tiny relative to these fields, you have bigger issues with coupling and eddy currents. It’s not quite as simple as field strength equals resolution, but generally it is easier to achieve high resolution with higher main field strength. See for example mouse scanners at 12T