Free Thyroxine Index (FT4I)

This method is a method of indirectly measuring FT4. The calculation formula is FT4I=total T4×the measured 125I-T3 uptake ratio T4 or PBI is affected by TBG; the 125I-T3 uptake test is also affected by TBG. Such as during pregnancy or after taking the contraceptive, the TB4 or PBI is increased due to the increase of TBG concentration in the blood, and is misdiagnosed as hyperthyroidism; the increase of TBG makes the 125I-T3 uptake rate correspondingly lower, which can be misdiagnosed as hypothyroidism. . The FT4I can avoid the effects of increased or decreased TBG. Basic Information Specialist classification: growth and development check classification: endocrine examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Seen in hypothyroidism. Normal value: FT4I: 2.2-14.0 Above normal: Found in hyperthyroidism, the use of thyroid hormone, heparin and other drugs. negative: Positive: Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. Normal value Radioimmunoassay 2.2 to 14.0. Clinical significance (1) Elevation is seen in hyperthyroidism, application of thyroid hormone, heparin and other drugs. (2) Reduced in thyroid dysfunction. Low results may be diseases: hypothyroidism results may be high disease may be: children with simple goiter, hypothyroidism, elderly hyperthyroidism precautions First, the precautions before blood draw 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the medical examination, you should start fasting for 12 hours to avoid affecting the test results. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection. Second, should pay attention after blood draw 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. 3. Please inform the doctor about the recent medication and special physiological changes before the test. Inspection process Radioimmunoassay. Not suitable for the crowd 1. Patients who have taken contraceptives, thyroid hormones, steroid hormones, etc., may affect the results of the examination and prohibit patients who have recently taken the drug history. 2, special diseases: patients with hematopoietic function to reduce disease, such as leukemia, various anemia, myelodysplastic syndrome, etc., unless the examination is essential, try to draw less blood. Adverse reactions and risks 1, subcutaneous hemorrhage: due to pressing time less than 5 minutes or blood draw technology is not enough, etc. can cause subcutaneous bleeding. 2, discomfort: the puncture site may appear pain, swelling, tenderness, subcutaneous ecchymosis visible to the naked eye. 3, dizzy or fainting: in the blood draw, due to emotional overstress, fear, reflex caused by vagus nerve excitement, blood pressure decreased, etc. caused by insufficient blood supply to the brain caused by fainting or dizziness. 4. Risk of infection: If you use an unclean needle, you may be at risk of infection.