Objective: Thyroid scintigraphy is the gold standard method to decide whether the hypothyroidism is permanent or not. We retrospectively evaluated scintigraphy results of patients who were referred to our department with the aim of determining role of thyroid scintigraphy in diagnosis of congenital hypothyroidism.

Materials and Methods: Thirty four patients attended nuclear medicine department for thyroid scintigraphy with diagnosis of congenital hypothyroidism (18 male, 16 female; 1day-12 years old) were included to the study. The hormone replacement was stopped 3-4 weeks prior to the scintigraphy. Patients were divided into 2 groups according to thyroid stimulating hormone (TSH) level at diagnosis: patients with TSH level below 30 mIU/L (mild hypothyroidism) were in Group 1 and patients with TSH level above 30 mIU/L (severe hypothyroidism) were in Group 2.

Results: Among 34 patients who were included into the study thyroid scintigraphies of 24 patients were normal (70.5%). There were 2 partial and 3 total suppressive, and 2 heterogen uptake in thyroid which were attributed to recent thyrotropin releasing hormone test. One patient had hemiagenesis, one with ectopic thyroid gland. One patient had indentation of left lobe but ultrasonographically normal. There were 11/17 patients (64.7%) who had normal thyroid scintigraphy in Group 1 and 13/17 patients (76.5%) in Group 2. Patients with hemiagenesis and ectopic gland were identified in Group 2.

Conclusion: Most of the patients with congenital hypothyroidism had normal thyroid scintigraphy. Considering the fact that even the most of the patients with severe hypothyroidism had normal scintigraphy; thyroid scintigraphy has to be performed in congenital hypothyroidism to decide permanency of the disease and to regulate the thyroid hormone replacement especially in iodine deficient countries.