Hyperparathyroidism is a condition characterized by excessive production of parathyroid hormone, usually by a benign parathyroid adenoma. Ultrasound is the primary imaging modality for localizing parathyroid adenomas before surgery. On ultrasound, a parathyroid adenoma typically appears as a small, hypoechoic, oval mass posterior to the thyroid gland, and color Doppler may show a characteristic feeding vessel entering the lower pole of the adenoma. Normal parathyroid glands are too small to be seen on ultrasound, so visualization of a parathyroid gland generally indicates it is enlarged. Combining ultrasound with sestamibi nuclear scanning improves the accuracy of preoperative localization.
Sonography Term