US of the Neck beyond the Thyroid Gland: Parathyroid Glands

Parathyroid imaging in hyperparathyroidism management is not solely to support the diagnosis but also to precisely localize abnormal parathyroid tissue, thus enabling minimally invasive parathyroidectomy. US offers a noninvasive and cost-effective method for identifying and characterizing parathyroid lesions. Common causes include solitary parathyroid adenoma, multiple adenomas, and parathyroid hyperplasia. Despite its advantages, US has limitations, including difficulty in demonstrating deep-seated or ectopic glands. Radiologists must exercise caution in distinguishing parathyroid lesions from mimics such as thyroid nodules and lymph nodes using various imaging modalities including high-resolution neck US, scintigraphy, four-dimensional CT, and MRI. The authors focus on the role of US in evaluating parathyroid pathologic conditions, highlighting its advantages in concurrent detection of thyroid nodules while also discussing the complementary role and benefits of alternative imaging modalities. Common mimics encountered during imaging evaluation are briefly outlined.