Anatomy of thyroid glandAnatomy of thyroid gland

What are the indications for What are the indications for thyroid ultrasound?thyroid ultrasound?

Diffuse enlargement on physical Diffuse enlargement on physical examinationexamination

A palpable massA palpable mass A non palpable mass seen on other A non palpable mass seen on other

imaging( CT-MRI- nuclear scan)imaging( CT-MRI- nuclear scan) Abnormal thyroid function testsAbnormal thyroid function tests

Thyroid diseasesThyroid diseases

Diffuse Diffuse Grave's diseaseGrave's disease Hashimoto Hashimoto

thyroiditisthyroiditis De Quervain's De Quervain's

thyroiditisthyroiditis

Focal Focal SolitarySolitary multinodularmultinodular

Solitary thyroid noduleSolitary thyroid nodule

BenignBenign malignantmalignant

General features of the General features of the solitary nodulesolitary nodule

Solid / cysticSolid / cystic Comet tail signComet tail sign MarginsMargins CalcificationCalcification Color flow imagingColor flow imaging

Solid/CysticSolid/Cystic Nodules with large Nodules with large

cystic components are cystic components are usually benign nodules usually benign nodules that have undergone that have undergone cystic degeneration or cystic degeneration or hemorrhage , however hemorrhage , however about 20-30% of about 20-30% of papillary carcinomas papillary carcinomas also have a cystic also have a cystic component, indicating component, indicating that not all cystic that not all cystic thyroid nodules are thyroid nodules are benign.benign.

Comet tail signComet tail sign

One highly specific One highly specific sign of a benignity sign of a benignity of a thyroid nodule of a thyroid nodule is the presence of is the presence of comet tail sign, comet tail sign, signifying a benign signifying a benign colloid nodule. colloid nodule. This sign is never This sign is never encountered in a encountered in a malignant lesionmalignant lesion

EchogenecityEchogenecity

Hyperechoic nodule Hyperechoic nodule malignant in malignant in 4%4%

Isoechoic nodule Isoechoic nodule malignant in malignant in 26%26%

Hypoechoic nodule Hypoechoic nodule malignant in malignant in 63%63%

Margins Margins Peripheral halo of Peripheral halo of

decreased decreased echogenecity is seen echogenecity is seen around the nodule.around the nodule.

a complete halo is 12 a complete halo is 12 times more likely to times more likely to indicate benign lesionindicate benign lesion

An incomplete halo is An incomplete halo is 4 times more likely 4 times more likely benign than benign than malignantmalignant

Calcification Calcification

Peripheral rim calcification and Peripheral rim calcification and large areas of coarse shadowing large areas of coarse shadowing calcifications are more frequently calcifications are more frequently seen in benign nodules’seen in benign nodules’

Fine punctate calcifications due to Fine punctate calcifications due to calcified psammoma bodies are more calcified psammoma bodies are more frequently seen in malignant nodulesfrequently seen in malignant nodules

Color flow imagingColor flow imaging There are three general patterns of vascular There are three general patterns of vascular

distribution of the thyroid nodule:distribution of the thyroid nodule: Type 1Type 1 : complete absence of flow signal : complete absence of flow signal

within the nodule.within the nodule. Type 2Type 2 : exclusive perinodular arterial flow : exclusive perinodular arterial flow

signalsignal““type 1 and 2” are more common with benign type 1 and 2” are more common with benign

nodulesnodules Type 3Type 3 : intranodular flow with or without : intranodular flow with or without

significant perinodular flow and this type is significant perinodular flow and this type is generally associated with malignant nodules.generally associated with malignant nodules.

Although none of the Although none of the ultrasound features above ultrasound features above

is is BY ITSELFBY ITSELF pathognomonic for pathognomonic for

malignancy, BUT when it malignancy, BUT when it used used IN COMBINATIONIN COMBINATION they they

are very useful in are very useful in differentiating malignant differentiating malignant

from a benign nodulefrom a benign nodule

What are the features of a What are the features of a benignbenign thyroid nodulethyroid nodule??

1- completely or nearly completely cystic, 1- completely or nearly completely cystic, especially with echogenic foci with especially with echogenic foci with comet tail artifactcomet tail artifact

2- echogenic or isoechoic to normal 2- echogenic or isoechoic to normal tissuetissue

3- a complete halo3- a complete halo

4- well described margin4- well described margin

5- rim or large coarse calcifications5- rim or large coarse calcifications

6- hypovasculrity6- hypovasculrity

What are the features ofWhat are the features of malignantmalignant thyroid nodule?thyroid nodule?

1- microcalcifications1- microcalcifications

2- irregular margin2- irregular margin

3- marked hypoechogenecity3- marked hypoechogenecity

4- hypervascularity4- hypervascularity

Examination of adjacent Examination of adjacent structuresstructures

(1)- (1)- CCA and CCA and internal jugular internal jugular veinvein : the presence : the presence of thrombus within of thrombus within CCA or IJV in CCA or IJV in association with a association with a thyroid nodule is a thyroid nodule is a clue to the clue to the malignant nature malignant nature of the noduleof the nodule

(2) – (2) – spread to adjacent spread to adjacent structuresstructures; extrathyroid spread ; extrathyroid spread including involvement of esophagus, including involvement of esophagus, trachea, strap muscles, recurrent trachea, strap muscles, recurrent laryngeal nerve is another clue to laryngeal nerve is another clue to the malignant nature of the nodulethe malignant nature of the nodule

(3)- (3)- cervical lymphadenopathycervical lymphadenopathy The LNs commonly involved are the The LNs commonly involved are the

pretracheal , paratracheal and nodes pretracheal , paratracheal and nodes along internal jugular vein.along internal jugular vein.

MULTINODULAR THYROIDMULTINODULAR THYROID

ultrasound features:ultrasound features: Solid nodules, frequently isoechoicSolid nodules, frequently isoechoic well defined marginswell defined margins Cystic component in 60 %Cystic component in 60 % Heterogeneous internal echopattern Heterogeneous internal echopattern

with multiple septa , solid and cystic with multiple septa , solid and cystic portions.portions.

On color flow imaging the nodules On color flow imaging the nodules either show type 1 or type 2 patterneither show type 1 or type 2 pattern

It is generally believed that malignancy It is generally believed that malignancy is common in a solitary nodule and that is common in a solitary nodule and that multinodularity is usually associated multinodularity is usually associated with benign disease, with benign disease, HOWEVERHOWEVER 10 – 10 – 20 % of papillary carcinoma may be 20 % of papillary carcinoma may be multicentricmulticentric

DIFFUSE THYROID DIFFUSE THYROID DISEASESDISEASES

• Grave's diseaseGrave's disease• Hashimoto thyroiditisHashimoto thyroiditis• De Quervain’s diseaseDe Quervain’s disease

GRAVE’S DISEASEGRAVE’S DISEASE

Diffuse enlarged glandDiffuse enlarged gland Color Doppler study is pathognomonic Color Doppler study is pathognomonic

for the disease , revealing for the disease , revealing hypervascularity which is called hypervascularity which is called “thyroid inferno”.“thyroid inferno”.

the peak systolic velocity is more than the peak systolic velocity is more than 100 cm/sec “normal up to 25 cm / sec”100 cm/sec “normal up to 25 cm / sec”

..

HASHIMOTO HASHIMOTO THYROIDITISTHYROIDITIS

Three stages:Three stages: Acute: enlarged in size and increased Acute: enlarged in size and increased

vascularity.vascularity. Chronic: enlarged gland with multiple Chronic: enlarged gland with multiple

linear bright echoes throughout the linear bright echoes throughout the hypoechoic parenchyma as well as hypoechoic parenchyma as well as multiple small hypoechoic nodules.multiple small hypoechoic nodules.

Atrophic; end stage : small atrophic gland. Atrophic; end stage : small atrophic gland. avascular with heterogenous echoes.avascular with heterogenous echoes.

..

DE QUARVAN’S DE QUARVAN’S THYROIDITISTHYROIDITIS

The inflammation does not involve The inflammation does not involve the entire gland but infiltrates the the entire gland but infiltrates the gland in a non homogenous pattern.gland in a non homogenous pattern.

The sonographic correlate is a The sonographic correlate is a disordered pattern of hypoechoic disordered pattern of hypoechoic and hypervascular areasand hypervascular areas

Evaluation of nodules Evaluation of nodules incidentally detected by incidentally detected by

U/SU/S

Nodules under 1.5 cm are Nodules under 1.5 cm are followed up by u/sfollowed up by u/s

Nodules over 1.5 cm are Nodules over 1.5 cm are further evaluated by FNAfurther evaluated by FNA

ILLUSTRATED ILLUSTRATED CASESCASES