Electrical signals generated by the brain which give rise to the EEG signal on the scalp create a magnetic field at the neuronal source of around 1 nano-Tesla (nT). Several authors have shown that changes in magnetic field of this order can be directly detected electromagnetically through MR signal modulation by high sensitivity MRI systems. An interesting fact is that this direct electromagnetic effect is independent of the strength of the magnetic field which is used for detection. Instead it is the stability of the system which controls the ability to detect such weak electromagnetic fields. This opens up the possibility of using low cost, open, low field strength MRI systems for dfMRI brain computer interfaces. Some authors have proposed the use of SQUID detection of fMRI at ultra-low field. Instead, we propose use of an intermediate, low cost, open MRI system used in conjunction with advance sensitivity enhancement methods such as cryogenic radiofrequency array coils together with polarization enhancement through the nuclear Overhauser effect (producing enhancements of ~10x) and dynamic nuclear polarization (producing enhancements of ~10,000x). Whilst this development is still in its infancy, much of the underlying technology required has already been proven and our future challenge is to integrate these sub-systems into a functional dfMRI based BCI device.