Neck Flashcards
Role of sonography in evaluating the thyroid gland
evaluate size, shape, echogenicity, and vascularity
Role of sonography in evaluating the neck for pathology
evaluate pathology for sonographic appearance, mass location, size, and vascularity
thyroid gland
An organ in the endocrine system that maintains body metabolism, growth and development.
location of the thyroid gland
Anterior, lower neck, (anteroinferior) inferior to the thyroid cartilage (below the Adam’s apple), on either side of the midline
thyroid gland consists of what parts
right and left thyroid lobe, isthmus, and pyramidal lobe
location of right and left thyroid lobes
sit on either side of the trachea
isthmus
connects right and left lobes
pyramidal lobe
If present, arises from isthmus and tapers or extends superiorly, but is most commonly seen in pediatric patients because it atrophies with age
normal adult thyroid size
4 to 6 cm long x 2 to 3 cm AP x 1.5 to 2 cm wide
thyroid size varies with what
gender, age, and body surface area and lobes are normally relatively equal in size
More common method used to determine if thyroid is enlarged
thyroid volume
thyroid volume is used to assess:
need for surgery or to determine the iodine-131 dosage to treat thyrotoxicosis
thyroid volume formula
Length x Width x Height (thickness) x .52
arterial blood supply to thyroid
2 superior thyroid arteries and 2 inferior thyroid arteries
2 Superior Thyroid Arteries branch from
External Carotid Arteries and descend to upper poles of thyroid
2 Inferior Thyroid Arteries branch from
Subclavian Artery and ascend to lower poles.
venous drainage of thyroid
2 superior thyroid veins and 2 inferior thyroid veins
venous drainage of thyroid drains into
internal jugular veins and brachiocephalic veins
anatomy located anterior to thyroid
3 strap muscles: sternothyroid, omohyoid, sternohyoid; and the sternocleidomastoid muscles
sonographic appearance of strap muscles
thin, hypoechoic bands anterior to thyroid
sonographic appearance of sternocleidomastoid muscles
larger oval band anterolateral to gland
anatomy located lateral to thyroid lobes
Common Carotid Artery and Internal Jugular Vein
anatomy located posterior to thyroid
parathyroid glands and longus colli muscles
anatomy located medial to thyroid
larynx, trachea, esophagus
esophagus located where
Sits medial to the left thyroid lobe between the trachea and the thyroid
sonographic appearance of esophagus
target in transverse plane (if unsure, have patient swallow. Esophagus will exhibit a peristaltic movement)
3 thyroid hormones
T3 (triiodothyronine), T4 (thyroxine) and calcitonin
T3 and T4 function
Stimulate cell metabolism: T4 (thyroxine) (the body’s way of breaking down food to convert to energy)
Function of calcitonin
plays a small role in regulating blood calcium levels
A low concentration of what hormones in the body causes a low BASAL METABOLIC RATE
thyroid hormones (T3 & T4)
A low basal metabolic rate in the body signals what
the hypothalamus that the body needs thyroid hormones
Hypothalamus secretes what hormone to tell the pituitary that the body needs thyroid hormones
thyrotropin regulating hormone (TRH)
Pituitary gland produces what hormone
thyrotropin, also known as TSH (thyroid stimulating hormone)
TSH causes what
the thyroid to release T3 and T4
High T4 and T3 indicates
hyperthyroidism
Low T4 and T3 indicates
hypothyroidism
low TSH with high T4 and T# indicates
hyperthyroidism
low TSH with low T4 and T# indicates
hypothyroidism
euthyroid
Normal thyroid function. The thyroid produces correct amount of thyroid hormone
primary thyroid dysfunction
Inherent dysfunction of thyroid gland itself
secondary thyroid dysfunction
Failure of pituitary gland or hypothalamus to properly signal the thyroid gland or dysfunction of pituitary or hypothalamus due to mass
most common thyroid disorder
hypothyroidism
hypothyroidism also known as
Myxedema
define hypothyroidism
Thyroid is not producing enough thyroid hormones (T3 & T4); under-secretion
most common cause of hypothyroidism
Hashimoto’s Thyroiditis, a chronic inflammatory
process caused by an autoimmune response that destroys thyroid cells
other causes of hypothyroidism
Low intake of iodine (goiter), Inability of thyroid to produce proper amount of thyroid hormone, Problem in pituitary gland
clinical signs and symptoms of hypothyroidism
- Weight gain
- Hair loss
- Increased subcutaneous tissue around eyes
- Lethargy
- Intellectual and motor slowing
- Cold intolerance
- Constipation
- Deep husky voice.
medical treatment for hypothyroidism
Synthetic thyroid hormones can treat, manage and
reverse symptoms. If left untreated, could lead to coma
extreme form of hyperthyroidism
Thyrotoxicosis
define hyperthyroidism
Production of too much thyroid hormones; oversecretion
causes of hyperthyroidism
- Entire gland is out of control
- Localized neoplasm (such as adenoma) causes overproduction of thyroid hormones
- Grave’s Disease
clinical signs and symptoms of hyperthyroidism
- Hyperthyroidism dramatically increases metabolic rate
- Weight loss
- Increased appetite
- High degree of nervous energy
- Tremor
- Excessive sweating
- Heat intolerance
- Palpitations
- Impaired fertility
- Exophthalmos (protruding eyes).
2 nuclear medicine tests are performed together to determine thyroid function:
- Iodine Uptake Scan
* Thyroid Scan
iodine uptake scan
Amount of radioactivity accumulated in the thyroid gland is measured at multiple time points for up to 24 hours
HIGHER % of radioactivity in thyroid gland than normal on iodine uptake scan indicates
hyperthyroidism
LOWER % of radioactivity in thyroid gland than normal on iodine uptake scan indicates
hypothyroidism
thyroid scan (nuc med) detects what
Detects the amount of radioactive tracer and uses it to create an image of the thyroid gland, showing the thyroid size, shape, and position
define hot nodule on nuc med thyroid scan
(hyper-functioning) concentrated spots of radioactivity. Considered to be benign
define cold nodule on nuc med thyroid scan
(nonfunctioning) areas with a lower concentration of radioactivity. More commonly seen. Have the potential to be malignant
before any ultrasound you should
- Review exam indication/diagnosis (on physician’s order)
- Review any available prior imaging
- Take a thorough patient clinical history
- Explain the examination procedure
clinical history prior to an starting the ultrasound exam should include
- Results of physicians examination (Is there a palpable mass?)
- Pain? If so, how long?
- History of hyperthyroidism or hypothyroidism?
- Symptoms related to hyper/hypothyroidism?
- Currently taking thyroid medication? If so, how long?
- History of any thyroid biopsy or surgery?
proper positioning for thyroid ultrasound
Supine position with pillow under both shoulders
• Neck extended with chin pointed toward ceiling
• When scanning each lobe sagittally, patient can slightly
turn face to opposite side (extending the neck on the side you are scanning). NOTE: this position causes dizziness once the patient sits up
transducer for thyroid ultrasound
High-frequency (7.5- to 15-MHz) linear-array
thyroid ultrasound should include what images?
- Each lobe of the thyroid in LONGITUDINAL and TRANSVERSE (lateral to medial and superior to inferior)
- Isthmus
- Survey of the area superior, inferior and lateral to document any enlarged cervical lymph nodes
normal sonographic appearance of thyroid
- Homogeneous texture
* Slightly more echogenic than the surrounding muscle
sonographic appearance of thyroid capsule
thin, hyperechoic line outlining the gland
sonographic appearance of trachea
curved structure with shadowing in the midline
transverse images to obtain of each thyroid lobe
- Superior
- Mid (with width measurement across the widest portion of the thyroid)
- Inferior
longitudinal images to obtain of each thyroid lobe
Align the transducer with the Common Carotid Artery, then begin to move medially.
• Lateral
• Mid (with length and height measurement)
• Medial
images to obtain of pathology
- Long (annotated with location: LONG RT THYROID LAT)
- Trans (annotated with location: TRANS RT THYROID SUP)
- Measurements in 3 planes
- Color
aplasia
Congenital absence (can be uni- or bilateral)
hypoplasia
Underdevelopment of any part of the gland
most common locations of ectopic thyroid
- Posterior to the tongue (sublingual) - most common location
- Other locations: near larynx or mediastinum
best imaging modality to view ectopic thyroid
scintigraphy
most common thyroid abnormality
goiter
goiter also known as
Nodular Thyroid Disease
goiters are more common in whom
women with increasing age
goiter caused by
Iodine deficiency is most common cause worldwide
2 types of goiter
goiter and multi-nodular goiter
define goiter
Overall enlargement
define multinodular goiter
Overall enlargement due to multiple nodules
define toxic goiter
Nodular enlargement that causes HYPERthyroidism
define nontoxic goiter
Nodular enlargement that doesn’t cause thyroid dysfunction.
clinical findings of goiter
- Visible protrusion on the neck
- Palpable enlarged thyroid
- Difficulty swallowing (dysphagia) caused by compression of esophagus
- Pressure on trachea
- Globus sensation (feels like something is stuck in your throat when you swallow)
- Clinical symptoms of hyperthyroidism or hypothyroidism
sonographic appearance of goiter
- Diffuse enlargement
- Localized nodules
- Appearance of nodules can vary
thyroid cyst usually a result of
cystic degeneration of a follicular adenoma
sonographic appearance of simple thyroid cyst
smooth walls, anechoic, posterior enhancement
sonographic appearance of colloid cyst
cyst with tiny echogenic focus
sonographic appearance of hemorrhagic cyst
low level echoes with possible fluid and debris, with possible internal septations
thyroid adenoma benign or malignant
benign
thyroid adenoma more common in whom
females
thyroid adenoma solitary or multiple
often solitary
thyroid adenoma slow or fast growing
usually slow growing
if hemorrhage of thyroid adenoma occurs, what symptoms may happen
sudden, painful enlargement
labs seen with thyroid adenoma
usually normal labs
thyroid adenoma characterized by
complete fibrous encapsulation
most common sonographic finding of thyroid adenoma
Thin, hypoechoic rim or halo (due to compressed tissue surrounding the adenoma
sonographic findings of thyroid adenoma
- MOST COMMON FINDING: Thin, hypoechoic rim or halo (due to compressed tissue surrounding the adenoma
- Calcification around the rim with an “eggshell” appearance may be seen
- Often homogeneous
- Size: varies
- Echogenicity: varies from anechoic to hyperechoic
Higher risk of malignancy with ______ nodules
solitary
Solitary nodule with ______ suggests malignancy.
cervical adenopathy on same side
clinical findings common with malignancy of thyroid
- Painless, palpable mass
- Hard
- Firm
- Solitary
- If more advanced: compression of adjacent structures causing: hoarseness, cough, or dysphagia
sonographic appearance of thyroid malignancy
- Any size, single or multiple.
- Solid, partially cystic, or mostly cystic mass
- Usually hypoechoic relative to normal thyroid
- Calcifications are present in 50% to 80% of all types of thyroid carcinoma.
- Increased vascularity may be present.
MOST COMMON thyroid malignancy (70% of all thyroid cancers)
papillary thyroid carcinoma
how aggressive is papillary thyroid carcinoma
least aggressive thyroid cancer
prognosis of papillary thyroid carcinoma
excellent if caught early
papillary thyroid carcinoma more common in whom
females age 20-40
papillary thyroid carcinoma associated with patients with history of
upper chest and neck radiation
papillary thyroid carcinoma usually metastasizes where
usually through lymphatics to nearby cervical lymph nodes
sonographic findings of papillary thyroid carcinoma
- Solid
- Hypoechoic (when compared to nearby strap muscles)
- Incomplete halo
- Ill-defined margins
- Microcalcifications that appear as tiny, punctate hyperechoic foci
- Hypervascular
- Ipsilateral Cervical lymph node metastasis (in approximately 20% of cases)
2ND MOST COMMON type of thyroid cancer (10-20% of all thyroid cancers)
Follicular Thyroid carcinoma
how aggressive is Follicular Thyroid carcinoma
more aggressive than papillary carcinoma
Follicular Thyroid carcinoma prognosis
worse than papillary carcinoma
Follicular Thyroid carcinoma more common in whom
females age 40-60
Follicular Thyroid carcinoma not associated with
upper chest and neck radiation
Follicular Thyroid carcinoma metastasizes where
through the bloodstream to bone, lung, brain and liver
sonographic appearance of follicular thyroid carcinoma
- Similar to a benign adenoma
- Irregular margins
- Thick irregular halo
- Tortuous internal blood vessels
medullary thyroid carcinoma slightly more common in whom
females
thyroid carcinoma that may be familial
medullary thyroid carcinoma
medullary thyroid carcinoma associated with
MEN 2 syndrome
medullary thyroid carcinoma metastasizes where
High incidence of mets to cervical lymph nodes
clinical findings of medullary thyroid carcinoma
Elevated calcitonin levels
sonographic findings of medullary thyroid carcinoma
- Solid hypoechoic mass with calcifications (similar to papillary carcinoma)
- Hypervascularity
- Cervical lymph node metastasis in advanced cases
anaplastic thyroid carcinoma is considered undifferentiated because
because it can be associated with papillary or follicular carcinomas
rare and most deadly thyroid cancer
anaplastic thyroid carcinoma
anaplastic thyroid carcinoma twice as common in whom
men, usually after age 60
50% of patients with anaplastic thyroid carcinoma have _____ mets
lung
90% of patients with anaplastic thyroid carcinoma have _____ mets
cervical lymph node
clinical findings common with anaplastic thyroid carcinoma
- Rapidly growing
- Hard, fixed mass
- Dyspnea: difficulty breathing
- Dysphagia: difficulty swallowing
- Hoarseness
- Cough
- Rapid growth, with invasion into surrounding neck structures and widespread mets, usually causing death by compression/asphyxiation
sonographic appearance of anaplastic thyroid carcinoma
• Large, hypoechoic mass, with invasion of surrounding structures
thyroiditis
Group of disorders that include inflammation of the thyroid with several causes (bacterial/viral infection, postpartum, post-radiation, drug induced, or autoimmune
all thyroiditis forms result in
hypothyroidism
3 types of thyroiditis
- Acute suppurative thyroiditis
- Subacute granulomatous thyroiditis (de Quervain’s disease)
- Chronic lymphocytic thyroiditis (Hashimoto’s disease)
cause of subacute De Quervain’s thyroiditis
Viral infection of thyroid
clinical findings of subacute De Quervain’s thyroiditis
- Inflammation of thyroid
- Dysphagia
- Fever
- Pain
- Tenderness
- Enlargement of thyroid
- Malaise
sonographic appearance of subacute De Quervain’s thyroiditis
may appear enlarged and hypoechoic
subacute De Quervain’s thyroiditis may cause
transient hyperthyroidism, but in period of weeks or months swelling and pain subside and gland functions normally
most common form of thyroiditis
Hashimoto’s Thyroiditis
Hashimoto’s Thyroiditis
Destructive autoimmune disorder that leads to chronic inflammation of thyroid
clinical findings of Hashimoto’s Thyroiditis
- Painless
- Enlarged thyroid gland
- Most often in young to middle-aged women
- Entire gland is involved but enlargement is NOT always symmetric
- Hypothyroidism
sonographic findings of Hashimoto’s Thyroiditis
- Heterogeneous thyroid
- Enlarged
- Micronodulation with ill-defined hypoechoic areas
- Color Doppler shows normal to decreased flow velocity
- “Thyroid inferno” seen once hypothyroidism develops.
- Cervical lymphadenopathy
Most common cause of hyperthyroidism
Graves’ Disease
Graves’ Disease
Autoimmune disease where immune system attacks thyroid and causes it to produce thyroid hormones
clinical findings of Graves’ Disease
- Characterized by a triad:
- Hypermetabolism
- Diffuse toxic goiter
- Exophthalmos (bulging eyes)
sonographic findings of Graves’ Disease
- May appear normal or
- May appear as an enlarged, heterogeneous (inhomogeneous) than a simple goiter
- Increased vascularity on color Doppler imaging, leading to term “thyroid inferno”
parathyroid glands
Paired endocrine organs; Calcium sensing organs
most people have how many parathyroid glands
four
parathyroid glands lie where
Two lie posterior to each superior pole of thyroid; two lie posterior to each inferior pole
parathyroid glands shape
Small, flat and disc-shaped
sonographic appearance of parathyroid glands
- Enlarged glands (>5 mm):
- Hypoechoic
- Elongated mass between posterior longus colli and anterior thyroid lobe
Normal-size glands (<4 mm) are usually not seen with sonography, often parathyroids are first evaluated with ________
Nuclear Medicine
function of parathyroid glands
Produce parathyroid hormone (PTH) and monitor serum calcium feedback mechanism
parathyroid hormone acts on what
PTH acts on bone, kidney, and intestines to increase calcium absorption into the blood
clinical history prior to an starting the ultrasound exam to evaluate parathyroid glands should include
- Previous diagnosis of parathyroid disease?
- History of: kidney stones, ulcers, pancreatitis or osteoporosis?
- History of: chronic renal failure or dialysis? (these could explain abnormal lab values due to secondary hyperparathyroidism)
- Recent serum calcium levels and PTH levels?
proper positioning for parathyroid ultrasound
- Supine position with pillow under both shoulders
- Neck extended with chin pointed toward ceiling
- Upper neck (jaw to sternal notch) evaluated, transverse and longitudinal planes of thyroid/parathyroid area
transducer for parathyroid ultrasound
High-frequency (7.5- to 15-MHz) linear-array
Primary hyperparathyroidism
Increased function of parathyroid glands
Primary hyperparathyroidism more common in whom
- More common after age 40
* More common in women, particularly after menopause
Primary hyperparathyroidism characterized by
Abnormal secretion of PTH, which signals more calcium to be secreted in the blood
Primary hyperparathyroidism lab findings
- Hypercalcemia
- Hypercalciuria
- Low serum levels of phosphate (hypophosphatemia)
Primary hyperparathyroidism symptoms
Usually asymptomatic
role of sonography in evaluating Primary hyperparathyroidism
- Determine if a mass is present or if parathyroid hyperplasia is present
- Mass could represent: parathyroid adenoma or parathyroid carcinoma
Secondary hyperparathyroidism
Occurs when PTH level is increased due to chronic hypocalcemia which is caused by renal failure, vitamin D deficiency (rickets), or malabsorption syndromes
Secondary hyperparathyroidism lab values
Elevated PTH level and low calcium levels
parathyroid hyperplasia
Hyperfunction of all parathyroid glands with no apparent cause
Hyperplasia usually involves _____ glands
all 4
Most common cause of primary hyperparathyroidism (80% of cases)
parathyroid adenoma
parathyroid adenoma benign or malignant
benign
parathyroid adenoma solitary or multiple
Usually solitary, but can involve one or more of the four glands
treatment for parathyroid adenoma
Surgical removal
sonographic appearance of parathyroid adenoma
- Oval
- Hypoechoic
- Homogeneous
- Usually solid
- Color doppler is usually peripheral (as opposed to hilar that is seen with lymph nodes)
lab values with parathyroid carcinoma
Very high Serum Calcium levels
clinical findings of parathyroid carcinoma
Small, irregular, firm masses
sonographic findings of parathyroid carcinoma
- Usually larger, more irregular in shape
- Lobulated contour
- May be taller than wide
thyroglossal duct cyst
Remnant of the tubular development of thyroid gland may persist between base of tongue and hyoid bone leaving a narrow hollow tract that usually atrophies with age.
Most common congenital cystic abnormality
thyroglossal duct cyst
thyroglossal duct cyst located where
midline of neck anterior to trachea, between the hyoid bone and the isthmus of the thyroid
thyroglossal duct cyst usually seen in whom
pediatric patients, younger than age 10
sonographic findings of thyroglossal duct cyst
- Characteristics of a cyst
* Oval or spherical masses rarely larger than 2 or 3 cm
Congenital cystic mass seen lateral to thyroid gland, in submandibular region
branchial cleft cyst
branchial cleft cyst seen in whom
Found more often in older children and young adults
sonographic findings of branchial cleft cyst
• Primarily cystic, but may have complex or solid components with low level echoes
clinical findings of abscess
- Pain
- Erythema
- Edema
- Fever
- Palpable mass
sonographic findings of abscess
- Varies: ranges from fluid-filled to completely echogenic
- Most commonly, mass of low-level echogenicity with irregular walls
- May show the presence of air with ring down artifact
- Chronic abscess may be particularly difficult to demonstrate because indistinct margins blend with surrounding tissue.
adenopathy
Enlargement of lymph nodes
lymph nodes can become enlarged due to
hyperplasia, metastasis or inflammatory process
sonographic findings of lymphadenopathy
- More rounded shape than normal lymph node
- Loss of echogenic hilum
- Lobular contour
