一位罹患甲狀腺乳突癌的17歲女性病患在甲狀腺全切除術後接受碘-131治療(100毫居禮)。治療後造影呈現一個「T-型」放射活性位於胸骨。其促甲狀腺激素剌激下的血清甲狀腺球蛋白數値低。沒有局部疼痛，發炎徵象，或是外傷病史。後續的X-光檢查正常，門診追蹤亦無轉移的臨床徵象。這個位於胸骨的「T-型」放射活性被認爲是由於骨髓的碘-131攝取，爲一僞陽性的結果。這提醒我們對於瀰漫型且對稱的骨豁攝取，必須小心判讀，避免造成甲狀腺癌骨骼轉移的過度診斷。

A 17-year-old female patient with papillary thyroid cancer received 1-131 therapy (100 mCi) after total thyroidectomy. The post-therapy scan revealed a “T-shaped” activity in the sternum. The TSH-stimulated serum thyroglobulin (Tg) level was low and the anti-Tg antibody (anti-Tg Ab) was negative. There was no local pain, no inflammatory sign, nor trauma history. Subsequent X-ray radiograph was normal and clinical sign showed no evidence of metastasis in out-patient follow-up. The “T-shaped” activity in the sternum was considered to be a false-positive finding, probably due to marrow uptake of 1-131. This reminds us that diffusely symmetric bone uptake, should be interpreted carefully to avoid an over-diagnosis of thyroid cancer bone metastasis.