Hi there! My name is Vinay. Let me see if I can give you some peace of Mind here. MRI s all depend on Magnets! No radiation and they are pretty harmless. The only thing you have to make sure is that you have no implants that could be attracted by the magnet in the machine. When I was in residency in Colorado, the duty doc room used to be taken up by my cheif and his girlfriend.. so i used to sleep in the MRI machine!! It was the only flat surface other than the gurneys in the ER. So don t worry, the MRI is harmless. Now the scar tissue at the operative site should not be causing any headaches as it s not under pressure and brain tissue can t feel normal sensations like pain. If you are having headaches.. look into any problems with the scalp wound or the bone (Skull) that they had to go through during the surgery. Scar tissue can hypertrophy (grow in size) over time, but its really rare and really really slow. So the MRI s will catch it if it does. Not to worry there. So relax, the scar tissue is harmless and so is the MRI. Make sure you get those scans done just as the doctors tell you too! Congratulations on beating back the GBM! I wish you the best of luck!