Sensitivity and specificity of ultrasonography in detecting thyroiditis

Ultrasonography (USG) is frequently used to diagnose thyroiditis. The accuracy of this diagnosis, however, is unclear. This study was performed to determine the sensitivity. and specificity of USG in detecting thyroiditis. Three hundred thyroid patients were enrolled in the study. The diagnosis of thyroiditis by USG and by antithyroid peroxidase (anti-TPO) antibodies was compared. Thyroiditis was determined in 75 of 300 thyroid patients by USG and in 180 of 300 patients by anti-TPO antibody measurement. Anti-TPO antibody was positive in 84.2% of the cases who were diagnosed by USG. This, compared with diagnosis by anti-TPO, USG had high specificity (90%) but low sensitivity (35%) for the diagnosis of thyroiditis. Thus, USG does not appear to be an efficient screening test for thyroiditis, but patients diagnosed are likely to have the disorder.