Color Doppler ultrasonography in patients with subacute thyroiditis

We studied the utility of color Doppler ultrasonography in patients with su bacute thyroiditis. Eighteen patients with subacute thyroiditis (SAT) with painful goiter and thyrotoxicosis underwent color Doppler ultrasonography d uring the acute and recovery stages of the disease. Thyroid vascularization in these patients was compared with that of 15 untreated patients with Gra ves' disease and 17 control subjects. During the acute stage of subacute th yroiditis, color Doppler ultrasonography showed low echogenicity without in creased tissue vascularity in the affected swollen thyroid. In the recovery stage, color Doppler ultrasonography showed isoechogenicity with slightly increased vascularization. Vascularization became normal at 1 year follow-u p time. In contrast, marked by increased vascularization was observed in pa tients with untreated Graves' disease. Color Doppler ultrasonography showed clear differences between SAT and Graves' disease patients. Vascularity wa s significantly correlated with serum free thyroxine (FT4) and thyrotropin (TSH) concentrations in the recovery stage (3 months after the initial ultr asonography). Color Doppler ultrasonography accurately visualized lesions w ithout increased vascularity in the acute stage of SAT and lesions of sligh tly increased vascularity in the recovery stage. Color Doppler ultrasonogra phy may be a useful, noninvasive, and rapid method for differentiating SAT from Graves' disease and for evaluating and monitoring the location and act ivity of lesions in SAT.