Ultrasound for Primary Imaging of Congenital Hypothyroidism

OBJECTIVE. The purpose of this study was to retrospectively evaluate the use of sonography as the primary imaging modality for congenital hypothyroidism (CH). MATERIALS AND METHODS. From our regional registry, we reviewed the cases of patients for whom either sonography or Tc-99m-pertechnetate scanning was performed for CH between 2003 and 2010. Ultrasound studies were reviewed for presence, size, echotexture, vascularity, and location of the thyroid gland. Technetium-99m-pertechnetate scans were evaluated for the presence and location of the thyroid gland. The ultrasound studies were compared with the Tc-99m-pertechnetate scans. We assessed the use of ultrasound as the primary imaging modality for the evaluation of CH. RESULTS. We identified the cases of 124 patients (89 girls, 35 boys). Ultrasound studies were available for 121 patients, and Tc-99m-pertechnetate studies for 62 patients. Three patients were examined only by Tc-99m-pertechnetate scanning. The final imaging results were normal location with normal size or diffuse enlargement of the thyroid gland (n = 47), sublingual thyroid gland (n = 49), agenesis (n = 18), hypoplasia (n = 8), and hemiagenesis (n = 2). Compared with Tc-99m-pertechnetate scanning, ultrasound had high (100%) specificity and low (44%) sensitivity for detection of sublingual thyroid gland. CONCLUSION. We suggest using ultrasound as the primary imaging modality for guiding the treatment of children with CH, potentially decreasing radiation exposure and cost.