Fig. 19

Physiological bio-distribution and normal variants of ¹¹C-choline 2-5 min after administration: main findings. a Normal biodistribution but a small amount of radioactive urine is present in the bladder; mild uptake in the thyroid. b The presence of intense uptake in the vessels in which the tracers has been injected is a relatively common finding; some mild thyroid uptake is present. c Moderate uptake in the bowel may be present. d Some diffuse faint uptake in the bone marrow may be present especially after treatments as a bone marrow rebound