PMI ABD 1 Head & Neck

Where is the thyroid located?

- Located in the anterior-inferior neck at the level of the thyroid cartilage

What are the three parts of the thyroid?

1. right pyramid lobe

2. left pyramid lobe

3. Isthmus- a bridge that connects the lobes

size of thyroid in children

L- 20-30 mm (2-3 cm), AP- 12-15 mm (1.2-1.5 cm) and W- 10-15 mm (1-1.5cm)

size of thyroid in adult

L- 40-60 mm (4-6 cm), AP- 20-30 mm (2-3 cm) and W- 15-20 mm (1.5-2 cm)

size of Isthmus

AP- 4-6 mm (.4-.6 cm)

Whats the volume of a thyroid

about 18.6 ml

What is anterior to thyroid?

- Strap muscles (sternothyroid, omohyoid, sternohyoid and sternocleidomastoid)

- Sternohyoid and omohyoid m:

- Appear thin, hypoechoic bands that lies anterior to gland

- Sternocleidomastoid m:

- Appears as large oval band that lies anterior/lateral to gland

What is posterior to the thyroid?

- Common carotid arteries, internal jugular veins, vagus nerve

- Longus colli muscles

- Lie posterior and lateral to gland

- Appear as hypoechoic triangular structure adjacent to cervical vertebrae

what is medial to the thyroid?

- Larynx, trachea, inferior constrictor of pharynx, and esophagus

- Esophagus

- Primarily a midline structure, although seen left of trachea

- Identified by target appearance in transverse and peristaltic movement with patient swallowing

Where does blood supply the superior thyroid arteries

- Arises from the ECA and

- Supplies upper poles

Where does blood supply the inferior thyroid arteries

- Arises from thyrocervical trunk of subclavian a.

- Supplies lower poles

What is the role of the thyroid?

-plays a major role in growth & development, as well as maintains normal body metabolism/regulates basal metabolism.

-This is all achieved by the synthesis, storage, and secretion of thyroid hormones.

What is thyrotropin?

A hormone released by the pituitary gland that helps increase levels of thyroid hormone

Define euthyroid

normal thyroid function

Role of calcitonin

- Decreases concentration of calcium in blood by first acting on bone to inhibit its breakdown.

- Helps to maintain homeostasis of blood calcium

Role of Thyroxine (T4)

Aids in the metabolism of fats, proteins, and carbohydrates

Role of Triiodothyronine (T3)

Aids in the metabolism of fats, proteins, and carbohydrates

How is a patient supposed to lay when doing ultrasound on thyroid?

supine position with pillow under both shoulders to provide moderate hyperextension of neck

What are some reasons someone may get an ultrasound of their thyroid?

- A palpable mass found within the neck

- Abnormal laboratory findings

- As a follow-up examination from nuclear medicine studies and other diagnostic imaging studies.

(true or false) A sonographer should determine if there are any palpable nodules by palpating the thyroid gland.

True

What is a goiter?

An enlarged, hyperplasic thyroid gland.

What are some causes of a goiter?

Iodine deficiency, Graves disease, and thyroiditis.

What will a goiter look like on an ultrasound?

Thyroid will be enlarged and heterogenous

How would you know if a goiter is considered a multinodular goiter or adenomatous goiter.

The enlarged thyroid gland that contains multiple nodules with cystic and solid components

What is graves disease?

HYPERTHYROIDISM!

- Autoimmune disorder is which there is an over secretion of thyroid hormones

- Occurs when entire gland is out of control or if localized neoplasm (such as adenoma) causes overproduction of thyroid hormone

- Pituitary gland senses high levels of thyroid hormone and decreases TSH

Clinical graves disease (signs & symptoms)

- Diffusely enlarged thyroid (goiter)

- Bulging eyes

- Heat intolerance

- Weight loss

- Palpitations, dyspnea on exertion

- Tremors, muscle weakness

- Excessive sweating

- Decrease in TSH, Increase in T4/T3

What does graves disease look like in an ultrasound?

- Enlarged thyroid

- May appear diffusely heterogenous or hypoechoic

- Hypervascularity of the thyroid gland, "thyroid inferno"

What is Hashimoto's Thyroiditis?

HYPOTHYROIDISM!

- Autoimmune condition in which there is destruction of the thyroid gland by one's own immune system

- Most common type of thyroiditis and cause of goiter

- As the gland becomes more damaged, it is less able to make adequate supplies of thyroid hormone.

- Pituitary gland senses low levels of thyroid hormone and secretes more TSH to stimulate the thyroid, causes thyroid to grow

- End-stage causes fibrosis and atrophy of thyroid

Clinical Hashimoto's Thyroiditis (signs & symptoms)

- Initially enlarged thyroid

- Depression

- Increased cold sensitivity

- Elevated blood cholesterol levels

- Slight weight gain may occur

- Puffy face and puffiness under the eyes

- Increase TSH, Decrease T3/T4

What does Hashimoto's Thyroiditis look like on an ultrasound?

- Mild enlargement of the thyroid gland

- Heterogeneous echotexture

- Multiple, ill-defined hypoechoic regions separated by fibrous hyperechoic tissue

- Hypervascular gland

What is fine needle aspiration?

A highly efficient way to determine the character of clinically or sonographically identifiable thyroid nodules.

What happens during the fine needle aspiration procedure?

- During this minimally invasive procedure, the tissue is numbed and a small needle is inserted in the nodule using sonographic guidance.

How does composition look on a thyroid nodule?

- Nodules that are cystic or almost completely cystic are almost universally benign.

- The greater the solid component, the higher the risk of malignancy.

How does Echogenicity look on a thyroid nodule?

- Thyroid cancers are usually hypoechoic relative to the adjacent normal thyroid parenchyma.

- A hyperechoic nodule is more likely to be benign.

What does shape say about a thyroid nodule?

A taller than wide shape is an insensitive but highly specific indicator of malignancy

What does Calcification say about a thyroid nodule?

- Peripheral or eggshell calcifications correlation with malignancy in the literature is variable.

- Fine and punctuate calcifications are more suggestive of malignancy

What does Margination say about a thyroid nodule?

- Benign thyroid nodules tend to have sharp, well defined margins

- Malignant lesions tend to have irregular or poorly defined margins.

- Lobulated or irregular margin refers to a jagged edge, with or without protrusions into the surrounding parenchyma

- Extensive extra-thyroidal extension invading adjacent soft tissue is a highly reliable sign of malignancy

What are Thyroid Adenomas?

- Benign neoplasms

- Most common masses identified within the thyroid gland

What are Follicular adenomas?

- Most common

- Typically homogenous, solitary, and encapsulated

What is the least common adenomas?

Papillary adenomas

What are Cystic lesions?

- May be simple cysts

- May contain a bright echogenic foci representing a colloid-filled cyst

What are the three types of thyroid cancers?

- Papillary Carcinoma

- Follicular Carcinoma

- Medullary Carcinoma

How many cases does Papillary Carcinoma account for?

75-80% of all cases

How many cases does Follicular Carcinoma account for?

10-20% of all cases

How many cases does Medullary Carcinoma account for?

about 5% of all cases

How do Papillary Carcinomas show in an ultrasound scan?

- Appears as hypoechoic mass

- With possible calcifications

- Major route of spread is through the lymphatics to nearby cervical lymph nodes

How do Follicular Carcinomas show in an ultrasound scan?

- Often encapsulated, similar to benign follicular adenomas and may be indistinguishable

- Tend to spread via the blood stream

- Distant metastasis to the lung and bone is more likely than metastasis to cervical lymph nodes

How many parathyroid glands are there?

4

Where are the parathyroid glands located?

posterior to the thyroid

What is the most common cause of enlargement of parathyroid gland?

Parathyroid Adenoma - PRIMARY Hyperparathyroidism

Clinical for Parathyroid Adenoma - Primary Hyperparathyroidism (signs & symptoms)

- Elevated serum calcium

- Elevated PTH (Parathyroid hormone)

What does Parathyroid Adenoma - Primary Hyperparathyroidism look like in an ultrasound scan?

Hypoechoic mass adjacent to the thyroid

What occurs in patients with chronic renal failure.

Parathyroid Adenoma- SECONDARY Hyperparathyroidism

Clinical Parathyroid Adenoma- Secondary Hyperparathyroidism (signs & symptoms)

- Increased serum phosphates

- Decreased serum calcium

What does Parathyroid Adenoma- Secondary Hyperparathyroidism look like on an ultrasound scan?

All four parathyroid glands enlarge

Exocrine glands that secrete saliva and the enzyme amylase are called _________?

Salivary Glands

What are the three Salivary Glands?

1. parotid,

2. submandibular

3. sublingual

(true or false) When abnormalities of the salivary glands are suspected, it is best to image both sides for comparison because many diseases impact both glands.

true

What is the Parotid Gland?

largest of the salivary glands

Where is the Parotid gland located?

- Bilaterally anterior to the ear and extend inferiorly

- Bounded anteriorly by the rami of the mandibles

- Bounded posteriorly by the mastoid processes of the temporal bones.

What is the main duct of the parotid gland?

Stensen's duct

How will the parotid gland show up on an ultrasound?

- Appear elliptical in the sagittal plane

- Round in the transverse plane

Where is the Submandibular Gland located?

- Bilateral submandibular glands are located beneath the floor of the mouth

- Bordered laterally by the body of the mandible

- Bordered superiorly by musculature

What drains the Submandibular Gland?

Wharton's duct

How will the Submandibular Gland appear on an ultrasound?

Appear more as a triangular shape

Where is the Sublingual Gland located?

- Bilateral under the tongue

- Anterior to the submandibular glands

How will the Sublingual Gland appeart on an ultrasound?

Appear round

What is Sjögren syndrome (SjS)?

- An autoimmune disease that affects all glands that produce moisture

- Leads to dysfunction of the salivary glands and severe dryness of the eyes, nose, skin, and mouth.

What is sialadenitis?

inflammation of the salivary glands

What is Sialolithiasis?

Salivary gland stone which is a calcification within the gland or duct

What is a pleomorphic adenoma?

benign common tumor of the salivary glands

Parotid gland (most common location)

What is a mucoepidermoid carcinoma?

- Most common malignancy of the salivary glands

- Typically starts in the parotid gland

How do Cervical Lymph Nodes- Normally look in an ultrasound?

- Oblong shaped hypoechoic structures

- With a distinguishable echogenic hilum

- Vascular flow seen in hilum

- Measure less than 1 cm

- When documenting lymph nodes it is important to mark location by using the "levels" of the neck

How do Cervical Lymph Nodes become abnormal

- Can result from infections and malignancy

Cliinical for abnormal cervical lymph nodes (signs& symptoms)

- Palpable neck mass

- Enlarged nodes may be painful

What is Cervical Lymphadenopathy?

- Enlargement of the cervical lymph nodes

- Can be established sonographically

How do abnormal cervical lymph nodes look on an ultrasound?

- Enlargement of the node >1cm

- Rounded shape

- Loss of the echogenic hilum

- Calcifications

- May be hyperemic or demonstrate abnormal vascular patterns with color Doppler

What is a Thyroglossal Duct Cyst

Benign congenital cysts located within the midline of the neck superior to the thyroid gland and near the hyoid bone.

Cliinical Thyroglossal Duct Cyst (signs & symptoms)

- Palpable neck mass

- Infected cysts may be painful

How do Thyroglossal Duct Cyst look on an ultrasound?

- Anechoic, well defined, and unilocular cyst

- Posterior enhancement

- May have internal components

What is a Branchial Cleft Cyst

Congenital neck cysts

Clinical Branchial Cleft Cyst (signs & symptoms)

- Palpable neck mass located near the angle of the mandible

- Infected cysts may be painful

How do Branchial Cleft Cyst look on an ultrasound?

- Anechoic mass

- Posterior enhancement

What is a Fibromatosis Colli?

- Rare pediatric fibrous tumor

- Located with the sternocleidomastoid muscle

Clinical Fibromatosis Colli (signs & symptoms)

- Pediatric palpable neck mass

- Torticollis - twisted neck with the chin angled to the non-affected side

How does Fibromatosis Colli look on an ultrasound?

- Fusiform-shaped mass within the sternocleidomastoid muscle

- Hypoechoic, hyperechoic, or even isoechoic to the adjacent tissue

- May also contain calcifications that shadow

- May yield a hyperemic patter with color Doppler