Anyone know enough about fMRI or similar technology to speak to whether this will ever be small enough for a wearable without an implant? Also, curious to know

Anyone know enough about fMRI or similar technology to speak to whether this will ever be small enough for a wearable without an implant? Also, curious to know if the problems with fMRI accuracy that invalidated hundreds of scientific papers were resolved? See http://www.sciencealert.com/a-bug-in-fmri-software-could-invalidate-decades-of-brain-research-scientists-discover http://www.sciencealert.com/a-bug-in-fmri-software-could-inv...