Color Doppler sonography: anatomic and physiologic assessment of the thyroid.

The purpose of this study was to assess the potential application of color Doppler sonography in thyroid imaging. Thyroid nodules and other thyroid pathology detected by color Doppler ultrasound and nuclear scintigraphy were compared in 115 patients. The majority of "cold" nodules demonstrated a peripheral rim of color flow and no internal color flow with color Doppler sonography. A large number of "hot" nodules demonstrated internal color flow. Color Doppler sonography was helpful in delineating nodules in otherwise inhomogeneous glands. We determined that color Doppler cannot reliably distinguish benign from malignant thyroid nodules; fine-needle aspiration biopsy remains the most accurate method in differentiating benign and malignant lesions. We suggest that color Doppler sonography plays only a limited role in the evaluation of nodular thyroid disease at this time. The color Doppler appearance of other thyroid disorders (including toxic multinodular goiter, Graves' disease, and thyroiditis) is discussed.