The background of the study. Ultrasonography can be used to identify thyroid nodules and also to provide information about the structure of thyroid tissue. This study evaluated the use of computerized gray-scale ultrasonography to quantitate thyroid echoes in patients with Hashimoto’s thyroiditis.
How the study was done. The study subjects were 77 patients with Hashimoto’s thyroiditis. Twenty-eight were euthyroid, 20 had subclinical hypothyroidism (high serum thyrotropin [TSH] and normal free thyroxine [T4] values), and 29 had overt hypothyroidism (high serum TSH and low free T4 values); 23 of the latter were receiving T4 and had normal serum TSH values. The results in these patients were compared with those in 50 normal subjects. Thyroid volume was measured using ultrasonography, and the echogenicity of the thyroid and strap muscles was measured by computerized gray-scale ultrasonography.
The results of the study. The thyroid density (echogenicity) in the patients with Hashimoto’s thyroiditis was lower than that in the normal subjects. Among the subgroups of patients with Hashimoto’s thyroiditis, the thyroid density was highest in those who were euthyroid, intermediate in those with subclinical hypothyroidism, and lowest in those with untreated overt hypothyroidism. There was no correlation between thyroid volume and density or between thyroid density and serum antithyroid antibody concentrations. Thyroid density was lowest and serum antithyroid antibody concentrations were highest in the untreated patients with overt hypothyroidism.
The conclusions of the study. Thyroid echogenicity, as measured by ultrasonography, is reduced in patients with Hashimoto’s thyroiditis, in proportion to the severity of hypothyroidism.
The original article. Loy M, Cianchetti ME, Cardia F, Melis A, Boi F, Mariotti S. Correlation of computerized gray-scale sonographic findings with thyroid function and thyroid autoimmune activity in patients with Hashimoto’s thyroiditis. J Clin Ultrasound 2004;32:136-40.