Complex cytological and ultrasound study was conducted in 300 patients with thyroid pathology exposed to 5-250 cSv. Benign goiter changes and autoimmune thyroiditis were detected in 66.2% while malignant thyroidal nodules--in 3.7%. Benign and autoimmune changes alone were in 38%. Pathomorphological features of nodular changes and autoimmune thyroiditis patterns as well as their ultrasound representations were identified.