Contrast-enhanced color Doppler ultrasonography in suspected parathyroid lesions

To assess the usefulness of US contrast media in the evaluation of patients with primary hyperparathyroidism, with a nodule showing US features of a primary parathyroid lesion but lacking the color Doppler US appearance of a parathyroid mass.

Thirteen patients (7 female, 6 male; age range 51-79 years) were examined with US before and after administration of a stabilized galactose-based microbubble contrast agent. Ten patients underwent surgery and the final histological examination demonstrated parathyroid adenoma in 9 cases and a mesenchymal benign nodule in 1 case. Three nodules were proved to be of thyroid origin at fine-needle aspiration biopsy.

The use of a US contrast agent resulted in a diagnostic gain compared to unenhanced studies in 12/13 cases. Color Doppler findings characteristic of parathyroid lesions were observed in 7/13 cases, of thyroid nodules in 4/13 cases, and nonspecific patterns in 2/13 cases. Contrast-enhanced color Doppler US can be proposed in selected patients in whom unenhanced color Doppler provides uncertain findings. Its ideal application should be the evaluation of cervical lesions without detectable intranodular flow at unenhanced Doppler studies. In these cases, the contrast agent helps in visualizing typical color Doppler signals of the parathyroid lesions ("vascular pole" and "mixed pattern").