Thyroid Ultrasound Flashcards

A set of 75 vocabulary flashcards covering thyroid ultrasound, including embryology, anatomy, hormonal function, exam techniques, and various benign and malignant pathologies based on lecture notes.

Thyroid

The first endocrine gland to develop in human gestation.

$3rd$ week

The gestational week in which the thyroid begins developing.

$1st$ trimester

The developmental timeframe by which the thyroid is fully functional and the thyroglossal duct has typically involuted.

Base of the tongue

The anatomical site where the thyroid gland originates and a common site for ectopic thyroid tissue.

Thyroglossal duct

A temporary tube connecting the base of the tongue to the thyroid's final anterior position.

Migration pathway

The route of the thyroid descending from the base of the tongue through the thyroglossal duct to a final position anterior to the trachea.

Involution

The normal process of the thyroglossal duct closing by the end of the first trimester.

Ectopic thyroid

The result of thyroid tissue failing to fully descend during embryogenesis, commonly found at the base of the tongue.

Accessory thyroid

Extra thyroid tissue that is left behind along the migration pathway during fetal development.

Butterfly-shaped

The normal anatomical shape of the thyroid gland, consisting of two lobes and an isthmus.

Isthmus

The central portion of the thyroid that connects the right and left lobes and crosses anterior to the trachea.

Strap muscles

The group of muscles located directly anterior to the thyroid gland.

Longus colli muscle

A muscle located posterior to the thyroid gland.

Esophagus

A posterior relation to the thyroid gland, usually found on the left side.

Vertebral body

A structure located posterior to the thyroid gland and longus colli muscle.

Trachea

The structure located medial to the thyroid lobes which the isthmus crosses anteriorly.

Common carotid artery

An artery located lateral to the thyroid lobes.

Internal jugular vein

A vein located lateral to the thyroid lobes alongside the common carotid artery.

Parathyroid glands

Endocrine glands situated directly posterior to the thyroid.

Recurrent laryngeal nerve

A nerve located directly posterior to the thyroid gland.

Homogeneous

The normal sonographic texture of the thyroid, characterized by uniform, medium-level echoes.

Hyperechoic

The normal echogenicity of the thyroid relative to the surrounding muscle, meaning it appears brighter.

Pyramidal lobe

A superior extension of the isthmus present in $15-30\%$ of individuals; a normal variant, not pathology.

Lingual thyroid

The most common site for ectopic thyroid tissue, located at the base of the tongue.

Thyroglossal duct cyst

A midline neck mass located near the hyoid bone resulting from a failure of the thyroglossal duct to close.

Hyoid bone

The anatomical landmark near which a thyroglossal duct cyst is typically located.

Sistrunk procedure

The surgical treatment used for a thyroglossal duct cyst to prevent recurrence.

T3 (Triiodothyronine)

One of the two primary hormones secreted by the thyroid to regulate metabolism and energy production.

T4 (Thyroxine)

A primary thyroid hormone regulating metabolism, heart rate, and growth.

TSH (Thyroid-stimulating hormone)

Hormone made by the anterior pituitary that stimulates the thyroid to produce T3 and T4.

Anterior pituitary

The gland responsible for producing and secreting TSH.

Metabolism

One of the key physiological processes regulated by T3 and T4 thyroid hormones.

Abnormal TFTs

An indication for a thyroid ultrasound involving results from thyroid function tests.

Palpable neck mass

A physical finding that serves as a common indication for performing a thyroid ultrasound.

Supine position

The required patient position for a thyroid exam, often with a shoulder roll and neck extension.

Shoulder roll

Used in patient positioning to help extend the neck during a thyroid ultrasound examination.

Neck extension

The necessary patient maneuver to provide optimal access and visualization of the thyroid during ultrasound.

High-frequency linear transducer

The type of ultrasound probe optimized for imaging superficial structures like the thyroid.

$$7-15\,MHz$$

The typical frequency range used for a thyroid ultrasound transducer.

Longitudinal plane

One of the two required scan planes for imaging each thyroid lobe during the ultrasound exam.

Transverse plane

The scan plane used to image the thyroid lobes and the isthmus.

Color Doppler

Ultrasound mode used to assess vascularity, hyperemia, or the presence of a thyroid inferno.

Hyperemia

Increased blood flow within the thyroid gland, often assessed using color Doppler.

Thyroid inferno

A pattern of extensive, marked hypervascularity seen on color Doppler in Graves disease.

Goiter

Terms used to describe an enlarged thyroid gland which can be heterogeneous with multiple nodules.

Multinodular goiter

A form of goiter characterized by multiple nodules and gland enlargement, often from iodine deficiency.

Nodular hyperplasia

Another term for a goiter or an enlarged thyroid gland with multiple nodules.

Iodine deficiency

A primary cause of both goiters and hypothyroidism.

Follicular adenoma

The most common benign tumor of the thyroid gland.

Peripheral halo

The hallmark sonographic feature of a follicular adenoma caused by a fibrous capsule.

Fibrous capsule

The anatomical structure that creates the peripheral halo seen around a follicular adenoma.

Simple thyroid cyst

An anechoic lesion with thin walls and posterior enhancement, often from adenoma degeneration.

Posterior enhancement

A sonographic feature of simple cysts where echoes behind the lesion are strengthened.

Complex cyst

A thyroid lesion containing debris, septations, or internal echoes.

Hypothyroidism

A condition characterized by the underproduction of thyroid hormones, often leading to fatigue and weight gain.

Hashimoto thyroiditis

The most common cause of hypothyroidism; an autoimmune disease where the immune system attacks thyroid cells.

Autoimmune disease

A category of condition, such as Hashimoto or Graves disease, where the body's immune system attacks its own tissue.

Weight gain

A clinical symptom of hypothyroidism associated with slowed metabolism.

Cold intolerance

A symptom of hypothyroidism where the patient cannot maintain body heat in cool environments.

Bradycardia

A clinical symptom of hypothyroidism characterized by a slow heart rate.

Levothyroxine

The standard hormone replacement therapy used for the treatment of Hashimoto thyroiditis and hypothyroidism.

Hyperthyroidism

A condition of thyroid hormone overproduction, most commonly caused by Graves disease.

Graves disease

An autoimmune disorder that is the most common cause of hyperthyroidism, characterized by overstimulated thyroid receptors.

TSH receptor antibodies

The specific antibodies in Graves disease that cause the thyroid to overproduce hormones.

Heat intolerance

A symptomatic feature of hyperthyroidism where patients are sensitive to warm environments.

Exophthalmos

The clinical condition of bulging eyes often seen in patients with Graves disease.

Taller-than-wide

A suspicious ultrasound shape of a thyroid nodule that increases the likelihood of malignancy.

Microcalcifications

Small, bright echoes within a thyroid nodule that strongly suggest papillary carcinoma.

Irregular margins

A sonographic feature of a thyroid nodule that is suspicious for cancer.

Papillary carcinoma

The most common form of thyroid cancer, accounting for approximately $80\%$ of cases.

Follicular carcinoma

A thyroid malignancy that is difficult to distinguish from an adenoma without pathology to confirm invasion.

Medullary carcinoma

A thyroid cancer arising from parafollicular C cells that is often associated with MEN II syndrome.

Parafollicular C cells

The specific thyroid cells from which medullary carcinoma originates.

Calcitonin

The hormone secreted by medullary carcinoma of the thyroid.

Anaplastic carcinoma

The thyroid cancer with the worst prognosis, known for being very aggressive and rapidly invasive.