Sunday, July 21
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What does a parathyroid ultrasound show?

    The human body is indeed a marvel. Imagine even the smallest structure as a cell can have a great effect on human’s health if it is affected. Health screening can help detect possible diseases or detect diseases earlier so that patients can get the right medical advice and treatment. Ultrasound is one of the many tests used in health screening. In this article, we will learn more about it and specifically parathyroid ultrasound.

    Do you know what a parathyroid is? The parathyroid consists of 4 small glands, each of the 2 parathyroid glands located on each side of the neck. Specifically, the gland is located behind the thyroid gland. The size of the gland is tiny, similar to pea. The parathyroid gland produces a hormone known as parathyroid hormone. Basically, parathyroid hormones play a role in the regulation of calcium in the blood. It manages the blood calcium level by altering the amount of calcium released from the bone into the bloodstream, removal of calcium through urination and increasing vitamin D metabolism in the kidney to increase blood calcium level by increasing absorption of calcium in the intestine.  

    Before going further on parathyroid ultrasound, you may want to know a bit more on ultrasound first. Ultrasound is an imaging test that uses sound waves to produce images of the structures inside the human body. There are 3 main types of ultrasound scan which are external, internal and endoscopic. Ultrasound can be used as a diagnostic tool to find the causes for diseases and as a therapeutic tool such as treating tumours. Ultrasound scan in most cases does not produce side effects unless there is usage of sedatives.

    Parathyroid glands typically not seen on ultrasound. Thus, when referring to parathyroid ultrasound, there should be suspicion that something is wrong with the parathyroid. There are few conditions that make clinicians consider performing parathyroid ultrasound such as signs or symptoms associated with active parathyroid (hyperparathyroidism), abnormal lab values specifically increased parathyroid hormone or calcium level and abnormal findings on other imaging studies. Parathyroid ultrasound may also be performed to evaluate recurrent disease of previous parathyroid surgery or ablation.  Follow up on identified parathyroid abnormalities can be an indication for a parathyroid ultrasound.

    What does a parathyroid ultrasound show to a clinician? As mentioned before, normal parathyroid glands are typically unseen by ultrasound. What can be seen on parathyroid ultrasound usually means an abnormal parathyroid. This includes images of overactive parathyroid glands located abnormally in the body, lesions showing active blood vessels activities and abnormal shaped parathyroid such as oval, bean-shaped or multilobulated hypoechoic mass with well-defined margin. Most cases only show one abnormal parathyroid but it can be multiple.

    Parathyroid ultrasound procedure itself is generally safe and painless. Patient typically does not need to do preparation but better be safe by asking if it is possible to eat or drink before the procedure. Patients need to remove all jewellery from head to neck. Procedure starts with the patient lying down on the exam table and pillow or shoulder roll under the neck. Examiner will spread gel on the neck before placing a probe known as a transducer. The transducer is then moved over the neck to get a picture of the parathyroid gland. Procedure ends when the remaining gel is wiped off. It may take time for the examiner to evaluate and inform the results. The parathyroid ultrasound procedure itself roughly takes 30 minutes.

   However, ultrasound may only discover abnormal parathyroid glands for up to 50 to 60% of the time. Patients will usually need more than just ultrasound as the imaging test. This means that patients often need a second imaging test that is more sensitive to detect the abnormal gland. Parathyroid CT may be suggested when possible as it is more sensitive and more specific in detecting abnormal parathyroid localization.

    Since we have been talking about parathyroid ultrasound most obviously seen in abnormal parathyroid gland, it is worth mentioning hyperparathyroidism as it is usually the cause for the abnormality. Hyperparathyroidism can lead to a high level of calcium in blood and this itself can be dangerous. Most cases of hyperparathyroidism are caused by non-cancerous growth of the parathyroid gland. In rare cases, it may be from malignancy. These are known as primary hyperparathyroidism. Secondary hyperparathyroidism is a body response to a long-term low level of calcium in blood such as in chronic kidney disease and vitamin D deficiency. Long-standing hyperparathyroidism that goes untreated such as in end-stage renal disease is associated with tertiary hyperparathyroidism. Symptoms of hyperparathyroidism mostly are feeling weak or tired throughout the day, frequent bowel movement, muscle weakness and aches in bones or joints. In severe cases, it may cause nausea, vomiting, loss of appetite, increased urination, thirstiness and weight loss. In the elderly, hyperthyroidism may be mistaken as depression or dementia.