in this case, the "physiological uptake" means the amount you'd normally expect, in other words there is nothing wrong there
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3097820/
"Glandular breast tissue may show moderate uptake of FDG and is relatively increased in pre-menopausal subjects and post-menopausal subjects taking hormone replacement therapy. Marked uptake may be seen in lactating breasts"
I'm assuming that you are referring to a PET scan? If so, uptake basically means the amount of radioactive sugar that is "taken up" in a particular area. The radioactive sugar is attracted to cancer cells, so if you have a cancerous lump, the radioactive sugar will concentrate in that area, causing it light up on the scan. The sugar is also attracted to certain infections and muscle activity, so PET scans can often show false positives.