The Use of 99m Tc‐Methoxy‐isobutyl‐isonitrile (sestaMIBI) Uptake on Scintigraphy ( 99m ‐STS) in Amiodarone‐Induced Thyrotoxicosis: Case Series and Review of the Literature

Figures

• 

  Figure 1. The 99m-STS with a dose of 21.8 mCi showed intense initial uptake of the tracer activity within the thyroid parenchyma followed by a near complete washout in the 3-hour delayed images suggestive of AIT-1. In addition, there is diffuse enlargement of the thyroid gland (left more than right) and physiologic pattern of tracer distribution observed in the nasopharyngeal mucosa, salivary glands, and imaged parts of the liver and myocardium. A photopenic area in the left chest region correlates with the pacemaker. (a) 10 min postinjection; (b) 3 hr postinjection.

• 

  Figure 2. The 99m-STS with a dose of 19.4 mCi showed intense initial intense uptake of the tracer activity within the thyroid parenchyma followed by bilateral symmetrical gradual washout of tracer activity in the 1-hour and 2-hour delayed images suggestive of AIT-1. (a) 15 min delay; (b) 1 hr delay; (c) 2 hr delay.

• 

  Figure 3. 99m-STS with a dose of 19.43 mCi showed an intense initial intense uptake of the tracer activity within both thyroid lobes (a) followed by a complete washout in the 2-hour delayed images (b) suggestive of AIT-1.

• 

  Figure 4. 99m-STS showed failure of localization of the tracer within the thyroid gland, by imaging criteria suggesting destructive effect of amiodarone to the function of the gland and confirming AIT-2 (a, b) 15 minutes delay high- and low-resolution images. (c, d) 1 hour delayed anterior and posterior images.

• 

  Figure 5. 99m-STS with a dose of 24.9 mCi demonstrating persistent activity in the right and left lobes of the slightly enlarged thyroid gland at 10 minutes, declining at 60 minutes' image confirming diagnosis of AIT-1.