Study of Normal Thyroid Uptake using Technisium-99m

Abstract

Thyroid gland is a vital endocrine gland in the body, estimation of its uptake and thyroid area are generally consider to be an important in several pathologic situations such as iodine deficiency, Goiter, thyroiditis, multi-nodular goiter and others. The aim of this study was to evaluate the normal range of thyroid uptake and determine the thyroid area in patients who has normal thyroid function test (T.F.T) and homogenous distribution of the radiotracer in Sudanese especially in Radiation & Isotope Center of Khartoum (RICK). This study includes 58 patients (91.5% Female, 8.5% Male) in different age, sex, center of origin and type of food and drink intake. For six months from Dec 2016 to May 2017. The most frequency of ages distribute as (25-35=31.03%, 15-25=29.3%), The thyroid uptake value in the gamma camera (mediso). The result of the study showed that the mean age was 33.6 ± 11 years old, the overall mean area of thyroid gland was 19.3 ± 3.78 cm². The mean area of right lobe was 7.7 ± 1.65 cm². The mean area of left lobe was 7.1 ± 1.84 cm². The right lobe area was significantly homogenous from left lobe area. Furthermore, a significant correlation was observed between thyroid area, weight and age of the subject. The normal range of thyroid uptake is in the range between (0.77% - 3.8%) and the thyroid area is in the range of (12.7 cm² to30.1 cm²) there was a direct relationship between thyroid uptake and the thyroid area that when the area increase the uptake increase that shown in the following equation: y= 0.054x + 0.89 where x refers to thyroid area and y refers to uptake in percent. The result also shown that when thyroid weight increase the uptake increase as shown in the following equation: y= 0.056x + 1.53 where x refers to thyroid weight and y refers to uptake in percent. And the result shown that when BMI increase the uptake decrease as shown in the following equation: y = - 0.033x + 2.82 where x refers to BMI and y refers to uptake in percent. Finally the result also shown that when patient age increase the thyroid uptake decrease as shown in the following equation: y = - 0.6x + 1.85 where x refers to patient age and y refers to uptake in percent.