123I is supplied as sodium iodide (NaI), sometimes in basic solution in which it has been dissolved as the free element. This is administered to a patient by ingestion under capsule form, by intravenous injection, or (less commonly due to problems involved in a spill) in a drink. The iodine is taken up by the thyroid gland and a gamma camera is used to obtain functional images of the thyroid for diagnosis. Quantitative measurements of the thyroid can be performed to calculate the iodine uptake (absorption) for the diagnosis of hyperthyroidism and hypothyroidism.