The relationship between occupational radiation exposure and thyroid nodules.

BACKGROUND: Considering that thyroid nodules and thyroid cancer occur more frequently in people chronically exposed to radiation, the aim of this study was to evaluate the prevalence of thyroid nodules in a population occupationally exposed to radiation in hospitals of Isfahan, Iran. MATERIALS AND METHODS: In this case-control study, the prevalence of thyroid nodules in staff members occupationally exposed to radiation was determined by ultrasonography. The results were compared with the results of another study among the adult population of Isfahan which selected by cluster random sampling method. The 2 studied groups were matched according to sex and age. RESULTS: The case and control groups included 124 and 471 persons, respectively. The prevalence of thyroid nodules in the case and control groups was 22.6% and 24.6%, respectively (p > 0.05). Although thyroid nodules were significantly more prevalent in females in the control group, no such difference was observed between females and males of the case group (p > 0.05). The number of thyroid nodules (single or multiple) and calcification were not different between the two groups (p > 0.05). In addition, hypoechogenicity of thyroid nodules was not different between the two groups for (p > 0.05). CONCLUSION: In our study, there was not any correlation between chronic occupational exposure to low dose of radiation and the risk of developing thyroid nodules. Further studies with larger sample sizes, at different doses of radiation, and considering iodine status and thyroid function are thus required.

Sonographic assessment of congenitally hypothyroid children in Iran.

INTRODUCTION: Considering the high prevalence of congenital hypothyroidism (CH) in Isfahan, it seems that it is necessary to investigate the aetiology of the disorder and its related factors. The aim of this study was to determine the aetiology of CH among children in Isfahan province. MATERIAL AND METHODS: In this cross-sectional study, the aetiology of CH and the volume of the thyroid was assessed using neck ultrasonography. The results of thyroid function screening tests were additionally recorded. The correlation between ultrasonographic findings and the level of TSH and as well as T4 was determined. RESULTS: During this study 385 CH patients aged 0-3 years were studied. According to ultrasonographic findings, in 19.9% of patients the aetiology of CH was dysgenesis (agenesis, ectopy, and hemiagenesis) and 80.1% had normal thyroid. Mean thyroid gland volume in all studied patients was 0.78 ± 0.44 mL. The prevalence of ultrasonographic findings was as follows: normal 80.1%, agenesis 12.7%, hemiagenesis 5.8%, and ectopy 1.4%. There was a significant correlation between thyroid volume and TSH and T4 and as well as between TSH and ultrasonographic findings (p 〈 0.05). CONCLUSIONS: In spite of the limitations of ultrasonography in the field of determining the aetiology of CH, it is an appropriate imaging tool for determining the volume of the thyroid gland in children. Considering that the rate of goitrous gland was low, it seems that iodine deficiency could not be responsible for the high rate of CH in this region.