[Qualitative evaluation of thyroid nodules with gray-scale contrast-enhanced ultrasound].

OBJECTIVE: To assess the feasibility of gray-scale contrast-enhanced ultrasound for characterizing thyroid nodules. METHODS: Forty thyroid nodules from 35 patients were studied both by conventional techniques and gray-scale contrast-enhanced ultrasound. Of the nodules examined, 15 were benign and 25 malignant. The enhancement of echogenicity was evaluated. The diagnosis was confirmed by surgical biopsy and histopathological examination. RESULTS: The study using gray-scale contrast-enhanced ultrasound showed absent contrast-enhancement in 9 of 25 malignant nodules and 1 of 11 benign solitary nodules; intense enhancement in 6 of 25 malignant nodules, with perfusion defect in the center; diffuse faint enhancement in 10 of 25 malignant nodules and 10 of 11 benign solitary nodules. Benign cystic nodules all showed absent enhancement in the cystic components and 2 of 4 intense enhancement in the solitary components. CONCLUSIONS: Gray-scale contrast-enhanced ultrasonography imaging may be a useful tool for evaluating the perfusion of thyroid nodules. Solitary nodules showing absent enhancement or intense enhancement with absent enhancement in the nodular center may suggest malignant.