Melissa,

the throbbing has been discussed before on some prior posts as a symptom of TOS--you may find them by searching.

I didn't understand why Dr Sanders' opinion varied so greatly fr. your ultrasound findings done by the Univ MN doctor. I'm sorry that you didn't get a second opinion in Denver but my layperson's rec would be to phone Sanders' office and ask him about the throbbing you are experiencing. Didn't you some additional tests in his office? And of course show it to the PT when you have your next visit. And if need-be you can have it evaluated by a local doctor whether or not you are willing to have surgery with them.

keep us posted!