Whole-body 131-I scan in thyroid cancer

Anterior view of the head, neck, and chest of a 131-I scan in a patient with differentiated thyroid cancer who underwent thyroidectomy five weeks earlier and had discontinued liothyronine therapy three weeks earlier. The scan was performed 24 hours after administration of 5 mCi (185 MBq) 131-I. The arrow indicates a thyroid bed remnant with a 24-hour iodine uptake of approximately 1.5 percent. Physiologic uptake can be seen in the nasopharynx, and physiologic blood pooling of the isotope is seen in the mid-chest. The patient was subsequently treated with 29 mCi (1073 MBq) of 131-I.