跳至主要內容
- I-131
- 有beta射線，可用於治療
- 也可用於RAIU (Radiation iodine update)
- γ-ray 364KeV可用於Whole body scan，但radiation dose較高易造成star artifact，且易造成thyroid stunning (>2-4mCi)
- 不適合thyroid scan，因為有beta射線，易thyroid stunning
- 半衰期8天
- 較易偵substernal goiter，有的地方先做I-123 scan看不到subternal goiter再做I-131 scan(50μCi)
- Whole body scan 2(1.5-4) mCi
- 治療Graves’ disease 5-15mCi，toxic nodule 20-30 mCi, ablation 30-150 mCi(>30需隔離)
- RAIU 5-10 μCi
- I-123
- Thyroid scan+RAIU 200-400μCi
- Whole body scan 1.5-2 mCi
- Tc-99m sodium pertechnetate
- 替代選擇
- 因radiation dose較低，常用在小孩
- 亦用在診斷Mechkel’s diverticulum, salivary gland
- thyroid scan 6mCi (2-10)
- Thyrotoxicosis
- RAIU ↑: Hashimoto, Graves’ disease
- RAIU -: Antithyroid drugs: propylthiouracil, Methimazole
- RAIU ↓: Subacute thyroiditis: thyrotoxic phase, 人工 (Thyrotoxicosis Factitia), Antihyroid drugs, Struma ovarii
- Hypothyroid
- RAIU ↑: Hashimoto
- RAIU -: Hashimoto, subacute thyroiditis (recovery phase)
- RAIU ↓: hypothyroidism
- Euthyroid
- RAIU ↑: Rebound after antithyroid drug withdrawal , Compensated dyshormonogenesis
- RAIU ↓: Decompensated dyshormonogenesis