How much radiation is there with a mri?

None: X-ray machines, ct and nuclear medicine involve radiation. Mri and ultrasound produce no radiation.

Well: Ultrasound uses sonic enery and actually MRI uses radiowaves which are electromagnetic radiation. But in the colloquial use of radiation you mean xrays or ionizing radiation. And both u/s and MRI does not use ionizing radiation.

None: At least not the type that causes cell injury. The radiation from X-rays is called ionizing radiation because it can damage tissue. There are radio waves and magnetic fields in an MRI machine. These don't damage tissue.