Does she have a programmable shunt?
[Programmable - The opening pressure of these shunts can be changed via an external magnet so that surgery is not necessary for a pressure change.
There are two manufacturers of programmable shunts, Codman (a Johnson & Johnson Company) which has 18 different pressure settings and Medtronics which has 5. The one down-side of a programmable shunt is that large magnetic fields can change the pressure setting.
As a result, if an MRI is needed the shunt will need to be reprogrammed immediately following the MRI. This does not mean that an MRI can't be done, it just means that you need to set up having the shunt reprogrammed ahead of time. Reprogramming is very simple, they just lay a device over the shunt and push a button, then use an x-ray to verify the setting. I have had several people ask about accidental reprogramming. This is incredibly rare and you can read more about this in a 7 year study about the overall performance of the Codman Hakim Programmable valve here. I do not have similar information on the Medtronics valve, if anyone has any such links please send them to me. ]