AVM Nidus needs to be visible on MRI for radios surgery (gamma knife)?

I’ve been told by one neurosurgeon that to do gamma knife surgery the AVM Nidus needs to be visible on MRI. Another neurosurgeon said that is not true. Anyone with gamma knife experience know what their situation was as it relates to MRI?

Mine couldn’t be seen with MRI, the location did show due to the bleed and created a “void”. The did two angios and utilized what they could see on the CT and MRI wth the angio to target with radiation. My gamma was successful on the angio about 31 months post gamma knife. We are all different but certainly worth talking to the neurosurgeon who specializes in the gamma knife. Take Care, John.

Thank you John. I met with second neurosurgeon today who said they it does not need to be visible on MRI. So difficult to pick a surgeon. So far I have only been in my local area but considering making a trip to NY or Boston. Thank you again for your reply and confirming that yours Nidus could not be seen on MRI