Sequence of 123-iodide human scintiscans after an intravenous injection, (from left) after 30 minutes, 20 hours, and 48 hours. A high and rapid concentration of radio-iodide is evident in the periencephalic and cerebrospinal fluid, choroid plexus, salivary glands, oral mucosa and the stomach. In the thyroid gland, I-concentration is more progressive, also in the reservoir (from 1% after 30 minutes, to 5.8 % after 48 hours, of the total injected dose) (Venturi, 2010).