Results for subject 1. A 58-year-old woman. 18F-FDG (5 MBq in 0.1-mL isotonic saline) was injected into the dorsal skin of each foot subcutaneously (s.c.) on the right and intradermally (i.d.) on the left. (a) Axial low-dose CT of the distal lower leg. The great saphenous veins (GSV) are indicated by arrows. Scan level corresponds to the horizontal dashed line in (d). (b) Axial PET superimposed on CT showing 18F-FDG activity in a deep vein in the right lower leg. In the left lower leg, 18F-FDG activity is visible both superficially in the GSV and deeply in a posterior tibial vein with a communicant vein. (c) Time-activity curve for blood samples from the medical cubital vein (MCV) and GSVs with either i.d. or s.c. depot placement. Note the logarithmic scale on the y-axis due to large differences in measured activity. (d) Thick-slab maximum-intensity-projection PET image of the lower body showing the activity distribution of 18F-FDG.