This is the guy who did mine. Note that he works with Sanders. Bottom line is that it shows some irregularity, but doesn't let the Dr. know where the prob is. Sanders only ordered the MAC test at my insistance. Sanders knew I had TOS based on his physical exam, he didn't need a MAC test to tell him that. If you and a TOS specialist are sure you have TOS, then more tests aren't neccessary. One then just needs to decide to have the exploratory surgery (TOS surgery) or not. Some tests to see if neck is involved might help. But once you know you have TOS, extra tests like the MAC test don't help ---- at least they didn't in my case. My MAC test was positive and Sanders went ahead with the pec minor surgery. That was a mistake because my problems are with my brachial plexus, subclavian vein, first rib, subclavius muscle, etc.
Sanders would have known this if he looked at my MRA. He did not because he didn't believe in the test. Angle looked at the MRA and said it gave him a good indication of what was going on inside. He feels they are useful. At this point, I'm not interested in any more tests (scalene block, etc.). I know I have TOS and so do the Doctors. The only thing left to do is to have surgery or live with pain management.


** The above is only my opinion based on my journey **