Functioning thyroid tissue containing sufficient radioiodine can be visualized by scanning the gland with a directional scintillation counter.(4) This visual representation of the gland is called a "scintigram." Scintigrams have been invaluable in the detection and study of both "toxic" and non-functioning nodules, diffuse enlargement in hyperthyroidism and the subsequent reduction in gland size after treatment, carcinoma, and aberrant thyroid tissue.