en Radiology Radiology Original Article Original Article <span style="font-family:Times New Roman;"><span style="font-size:14px;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> The normal reference values for the thyroid uptake of radioactive iodine and Tc-99m pertechnetate in euthyroid patients vary by geographical location as well as the amount of iodine intake in the diet. The present study examines the normal reference values for thyroid uptake of Tc-99m pertechnetate in the North of Iran.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> The participants of this study were 64 patients (all over 20 years of age) who had referred to the Nuclear Medicine Center of the Shahid Beheshti Hospital for thyroid scan over the period between March 2018 and May 2020. It is worth mentioning that relying on laboratory test results, only patients with normal thyroid function were included in this cross-sectional study.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b> The median, the 5^th and 95^th percentiles and thyroid uptake range of 99mTc-pertechnetate in euthyroid patients were 0.9, 0.6 to 1.8% and 0.54 - 1.80%, respectively.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> The percentage of uptake in the thyroid gland in each geographical area varies based on race and diet content, so it is necessary to determine the percentage of uptake in each specific region and even check it periodically.</span></span></span><br> &nbsp; Thyroid Uptake, Tc-99m pertechnetate, Hyperthyroidism, Radioiodine 459 465 http://caspjim.com/browse.php?a_code=A-10-2269-1&slc_lang=en&sid=1 Amir Gholami amir_gholami_4@yahoo.com 100319475328460048954 100319475328460048954 No Department of Radiology, School of Medicine, Babol University of Medical Sciences, Babol, Iran Nima Armaghan Drnimaarmaghan@gmail.com 100319475328460048955 100319475328460048955 No School of Medicine, Babol University of Medical Sciences, Babol, Iran Hoda Shirafkan hodashirafkan@gmail.com 100319475328460048956 100319475328460048956 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran Mehrangiz Amiri alborz812002@yahoo.com 100319475328460048957 100319475328460048957 No Department of Radiology, School of Medicine, Babol University of Medical Sciences, Babol, Iran Seyyed Hossein Mousavie Anijdan shmosavia@gmail.com 100319475328460048958 100319475328460048958 Yes Department of Radiation Technology, Allied Medicine Faculty, Babol University of Medical Sciences, Babol, Iran