I do not think that your spiritual development should be halted if you do an MRI. It creates a very strong magnetic field and fires RF pulses at you. The relaxed RF pulses is used to detect information.
That said, I recommend you to maximize AoP(Aura of Protection) and AoC(Aura of cleaning) before the MRI. Increase the intensity of these two meditations by a factor of 2. Know that in your mind that MRI or radiography won't hinder you in any way at all.