[Ultrasonographic diagnosis of parathyroid glands]

Enlarged parathyroid glands are, if their localization is typical behind the thyroid gland, during basic USG examination with 5 MHz to 10 MHz using a linear probe, hypoechogenic or anechogenic, larger than 0.5 cm, oval in shape, elongated in a cranoiocaudal direction, separated from the thyroid gland. During swallowing they move upwards. Such a picture may be simulated also by enlarged lymph nodes, sympathetic ganglia a cranked vessel or oesophagus. By using coloured Doppler sonography in the algorithm of examinations the percentage of falsely positive findings may decline. Between 90 degrees and 270 degrees the vascular arch is sought which is formed by the branch of the a. thyroidea inferior. This vascular arch is found only when the parathyroid is involved, even when it is located in the parenchyma of the thyroid gland.