Value of the Left Inferior Thyroid Artery Peak Systolic Velocity in Diagnosing Autoimmune Thyroid Disease

Objectives-The purpose of this study was to calculate a number of thyroid grayscale and Doppler sonographic parameters in healthy individuals and patients with Hashimoto thyroiditis or Graves disease and assess their sensitivity and specificity for the diagnosis of autoimmune thyroid disease using receiver operating characteristic curves. Methods-A consecutive series of 153 patients (70 euthyroid and 54 hypothyroid patients with Hashimoto thyroiditis and 29 patients with Graves disease), all selected from an outpatient endocrine clinic, and 48 age- and sex-matched healthy control participants were evaluated with grayscale and power Doppler sonography. Results-An irregular echo pattern in the thyroid parenchyma had 92.8% sensitivity for the diagnosis of autoimmune thyroid disease, and a left inferior thyroid artery peak systolic velocity (PSV) greater than 26.11 cm/s had 91.7% specificity. Of 8 patients with Hashimoto thyroiditis and normal grayscale sonographic characteristics, 6 had a left inferior thyroid artery PSV greater than 26.11 cm/s. A left inferior thyroid artery PSV greater than 61.65 cm/s had 82.8% sensitivity and 86.9% specificity for differentiating Hashimoto thyroiditis from Graves disease. Conclusions-The left inferior thyroid artery PSV was the most accurate sonographic parameter for the diagnosis of autoimmune thyroid disease. Measurement of the inferior thyroid artery PSV could be used in patients with a normal grayscale sonographic appearance and inconclusive clinical and biochemical parameters to substantiate the diagnosis of autoimmune thyroid disease. Further studies are needed to evaluate and expand the use of this index.