Answer
See explanation below.
Work Step by Step
Generally dietary I- is incorporated into some specific hormones by the healthy thyroid gland. In order to assess the thyroid function a patient is allowed to drink a solution having a little amount of Na 131 I. Now the patient is scanned for flow of Na 131 I into the thyroid gland. For taking image of lungs, liver and heart often technetium-99 is used.