99mTc-sestamibi thyroid uptake in euthyroid individuals and in patients with autoimmune thyroid disease

Abstract

Five minutes is the optimal time interval between (99m)Tc-sestamibi injection and calculation of thyroid uptake. Five-minute uptake differentiates euthyroid individuals from GD patients. There is a high correlation between (99m)Tc-sestamibi and (99m)Tc-pertechnetate uptake in GD. The reduced (99m)Tc-sestamibi uptake in AHT patients is probably due to glandular destruction and fibrosis. Inflammatory infiltrate and high mitochondrial density in thyrocytes possibly explain the increased uptake in GD and HHT.

Tc-99m Sestamibi Thyroid Imaging in Patients on Chronic Amiodarone Treatment

“…The sestamibi's biodistribution is characterized by a rapid blood clearance and early uptake by target organs. 6,7,10 The most accepted mechanism of Tc-99m sestamibi uptake by myocardial cells is based on passive diffusion of the tracer through plasma and mitochondrial membranes. In normal conditions, there is a strong negative transmembrane potential which promotes the tracer concentration in the internal mitochondrial matrix.…”

“…Metabolic alterations can result in decreased Tc-99m sestamibi uptake. 6,7,10,11 The main advantage of the use of Tc-99m sestamibi over 131I-iodine and Tc-99m pertechnetate in thyroid scintigraphy is the thyroid uptake mechanism which is not altered by iodine overload and antithyroid drugs use. Some authors demonstrated that the previous perchlorate intake does not decrease Tc-99m sestamibi uptake, which points out that its uptake is not mediated by the same mechanisms as iodine.…”

“…The reference thyroid uptake values of both radiopharmaceuticals had previously been standardized in our laboratory. 7,8 An extra patient who had been studied was excluded from all analyses because he had hypothyroidism compensated with levothyroxine intake.…”

“…6 We have previously demonstrated that Tc-99m sestamibi can be used as an alternative radiopharmaceutical for thyroid scintigraphy and uptake in patients with Graves' disease and Hashimoto thyroiditis. 7 This study was aimed to evaluate the usefulness of Tc-99m sestamibi thyroid scintigraphy in patients on chronic use of amiodarone and compare the uptake and image patterns using Tc-99m sestamibi with standard Tc-99m pertechnetate thyroid scintigraphy.…”

Otoimmün Tiroid Bezi Hastalıklarında Tükürük Bezi Tutulumunun Tc-99m MIBI İle Değerlendirilmesi

“…Olgulara 370 MBq (10 mCi) Tc-99m MIBI intravenöz yoldan verildi (9). Görüntüleme için çift başlı gama kamera (Infinia, GE Medical Hipotiroidi tablosundaki otoimmun tiroiditli bireylerde tükrük bezi salgı miktarı düşük (%57) saptanırken, hipertiroidili hastalarda tükrük bezi salgı miktarının daha fazla olduğu (%75) belirlenmiştir.…”