Hi Mike,
The LHBT enthesis is actually the superior labrum of thew GH joint.
It is an unusual tendon to not have a traditional bony enthesis at its origin.
The small herniation pits that you may notice adjacent to the LHBT in the region of the rotator cuff interval are actually from the joint capsule attachments where the SGHL attaches.
In your case there is flow across the enthesis of the SGHL attachment.
There is also excess flow in the LHBT sheath.
Given the seronegative history it is all likely related to this condition.
Whenever i see multi locational disease I think about the possibility of an underlying mechanism like rheumatoid, gout out seronegative disease.
In seronegative it is the enthesis that is mainly affected.
Like rheumatoid, seronegative patients will get occasional flare ups in different locations from time to time. Not necessarily all at the same time.
I would tell the rheumatologist that the SGHL enthesis has a small pit in the bone and flow across the enthesis as well as increased flow in the LHBT sheath consistent with the known seronegative condition.
Steve