Sodium pertechnetate is the inorganic compound with the formula NaTcO₄. This colourless salt consists of the anion [TcO₄]. The radioactive TcO₄ anion is an important radiopharmaceutical for diagnostic use. The advantages to Tc include its short half-life of 6 hours and the low radiation exposure to the patient, which allow a patient to be injected with activities of more than 30 millicuries. Na[TcO₄] is a precursor to a variety of derivatives that are used to image different parts of the body.