The significance of thyroid blood flow at the inferior thyroid artery as a predictor for early Graves’ disease relapse

Summary Objective  We investigated the clinical usefulness of thyroid blood-flow measurement in predicting relapse of Graves’ disease (GD) in comparison with known risk factors for GD relapse. Measurement  Thyroid blood flow was measured in pulsed Doppler mode at the inferior thyroid artery (ITA), and the peak systolic velocity (PSV) calculated. Patients  ITA-PSV was measured in euthyroid GD patients (n = 79) immediately before withdrawal of anti-thyroid drug (ATD) and in healthy subjects (n = 17). Results  In the 79 euthyroid GD patients, the values of free triiodothyronine (FT3), TSH receptor autoantibody (TRAb), ITA-PSV and thyroid volume were significantly higher in the relapse group (n = 40) than in the nonrelapse group (n = 39) and the Youden index of ITA-PSV was significantly higher than that of FT3, TSH, TRAb and vascular endothelial growth factor (VEGF). Conclusion  ITA-PSV may assist in the prediction of early GD relapse after ATD withdrawal.