As I know nothing about the MRA/MRI/MRV, I can't address that, but FWIW, I was told by Dr. Sanders that he would never base a surgical decision on an EMG/NCV, as they can vary from day to day. (This was even referring to the neurologist he uses, who does a specialized TOS-specific testing procedure.) A neurosurgeon recently told me that they are only helpful when they are positive (IOW, a neg. test doesn't mean much...)