I was suspected of having Bow Hunters Syndrome because I develop diplopia when I turn my head to left or right. To rule out this diagnosis, I was only given a CT scan of head and neck with IV Contrast. As I understand it from WebMD, “Your doctor may be able to spot the cause with imaging tests like an ultrasound, CT scan, or MRI (magnetic resonance imaging).

But the best way is a test called digital subtraction angiography, which is a sort of X-ray of your arteries. You might hold your head normally for one test, then move it in the direction that causes the problem for a second.” https://www.webmd.com/brain/bow-hunters-syndrome

I am not sure Mayo has this type of scan but if not, shame on them. Prior to my ACDF, I will have a consult with a Dr. Shepherd, who is a vascular medicine specialist, and am hopeful he will order at least a digital subtraction angiography. Other tests doctors should consider using include the color-coded Doppler test, magnetic resonance angiography; transcranial Doppler ultrasound; and vertebrobasilar deprivation testing, all of which I will discuss with Dr. Shepherd.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5495592/
Will try to keep you posted.