甲狀腺疾病診斷

TSH
   正常: secondary (central dz)
   高:
       FT4:
           高: central 甲亢 (分泌TSH腺瘤) / thyroid hormone resistance
           正常: sub-clinical hypothyroidism
           低: Primary hypothyroidism
   低:
       -central 甲低;
       -primary/subclinical 甲高;
       -急性medical or surgical illness;
       -drugs (dopamine, 高劑量steroid)
       FT4:
           低: central hypothyroidism
           正常: sub-clinical 甲亢
           高: Primary 甲亢
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Primary 甲亢
   RAIU:
      Diffuse: homogeneous = Graves' dz
                    heterogeneous = toxic MNG (multinodular goiter)
      Focal: functioning tumor (腺瘤)
      None=>TG (Thyroglobulin) 
                        高: thyroiditis; struma ovarii; iodine load
                        低: thyrotoxicosis factitia 

Graves' dz
      臨床: 
           -Goiter (diffuse, 無壓痛, thyroid bruit)
           -Ophthalmopathy (50%, ~90%) (眼窩旁水腫, 眼瞼後縮, 眼球突出, 結膜炎, 複視(EOM侵犯)
                  -與抽菸有關
                  -stare 及 lid lag 可見於任何甲亢症
           -脛前水腫 (pretibial myxedema) (3%): infiltrative dermopathy)
       LAB:
         甲狀腺抗體 :
             TSI (thyroid stimulating Ig), (80%)
             TBII (thyrotropin-binding inhibitory Ig),  (80%)
             anti-TPO ( anti-thyroid peroxidase) (low titer)
             anti-thyroglobulin (anti-TG) 
          ANA