Contrast-enhanced color doppler ultrasonography in suspected parathyroid lesions

Purpose: To assess the usefulness of US contrast media in the evaluation of patients with primary hyperparathyroidism, with a nodule showing US featur es of a primary parathyroid lesion but lacking the color Doppler US appeara nce of a parathyroid mass. Material and Methods: Thirteen patients (7 female, 6 male; age range 51-79 years) were examined with US before and after administration of a stabilize d galactose-based microbubble contrast agent. Ten patients underwent surger y and the final histological examination demonstrated parathyroid adenoma i n 9 cases and a mesenchymal benign nodule in 1 case. Three nodules were pro ved to be of thyroid origin at fine-needle aspiration biopsy. Results and Conclusion: The use of a US contrast agent resulted in a diagno stic gain compared to unenhanced studies in 12/13 cases. Color Doppler find ings characteristic of parathyroid lesions were observed in 7/13 cases, of thyroid nodules in 4/13 cases, and nonspecific patterns in 2/13 cases. Cont rast-enhanced color Doppler US can be proposed in selected patients in whom unenhanced color Doppler provides uncertain findings. Its ideal applicatio n should be the evaluation of cervical lesions without detectable intranodu lar flow at unenhanced Doppler studies. In these cases, the contrast agent helps in visualizing typical color Doppler signals of the parathyroid lesio ns ("vascular pole" and "mixed pattern").