Normal Parathyroid Glands Are Most Often Seen on Neck Ultrasound.

Area of Science:

• Radiology
• Endocrinology
• Anatomy

Background:

• Traditionally, normal parathyroid glands (PTGs) were considered invisible on ultrasound (US).
• Recent research suggests PTGs exhibit specific US characteristics: ovoid shape, homogeneous echotexture, and hyperechogenicity.
• Understanding normal PTG visualization is crucial for accurate diagnosis and surgical planning.

Purpose of the Study:

• To determine the detection rate, standard dimensions, and common locations of normal PTGs during thyroid US examinations.
• To investigate whether goiter or thyroiditis influences the visualization of normal PTGs.

Main Methods:

• A prospective, single-center study involving 192 patients undergoing thyroid US.
• Identification of PTGs based on previously described US features.
• Analysis of detection rates, gland dimensions, locations, and the impact of thyroid conditions.

Main Results:

• Normal PTGs were visualized in 75% of patients (144/192).
• The most common locations were the lower thyroid pole and infra-thyroid region (66%).
• Mean PTG size was approximately 5.68 x 4.05 x 2.68 mm, with a mean volume of 33.3 mm³; goiter hindered visualization, while thyroiditis facilitated it.

Conclusions:

• Ultrasound detection of normal PTGs is feasible in a high percentage of cases (75%).
• Identifying normal PTGs aids preoperative assessment for thyroid and parathyroid surgery, potentially reducing hypoparathyroidism risk.
• Knowledge of normal PTG anatomy improves detection of abnormal glands and enhances postoperative surveillance accuracy.