However, if the sympathetic nervous control of the microvasculature is interfered with, vessels that are normally closed now open up (mechanism 5, "recruitment"), and areas of osteoid not
normally exposed to tracer are able to take it up. This "hyperemic" phenomenon is seen after
sympathectomy, stroke, fracture, osteomyelitis, and peripheral neuropathies; the counting rate will be less than twice that over normal bone.
Mechanisms of Skeletal Tracer Uptake
N. David Charkes
Temple University Hospital, Philadelphia, Pennsylvania
J Nucl Med 20: 794-795, 1979