High frequency transducers ( 7.5 – 15.0 MHz )
Linear array transducers
Doppler examination provided
Examine in supine position with the neck extended
Examine in both transverse and longitudinal plane
Thyroid - located in the anterior inferior neck, lateral lobes
on either side of the trachea
- the thyroid is an endocrine gland that secretes three
major hormones: thyroxine, triidothyronine and
Hyperechoic to adjacent muscles
Scattered readily detectable internal vessels
Lobes less than 2 cm anteroposterior (ap) and transverse Isthmus
less than 4 mm
Lobes Length : 4 to 6 cm
Width : 1.5 to 2 cm ( AP diameter )
Height : 2 to 3 cm
Isthmus: less than 4 mm
Newborn: Length:18 to 20 mms
AP : 12 to 15 mms
1 year : Length: 25 mms
AP : 13 to 18 mms
Transverse extended-field-of-view scan of the neck shows the
normal right and left lobes of the thyroid (T) located on either
side of the Shadowing produced by the trachea (Tr).
The common carotid arteries (C) and the right internal jugular
vein (V) are seen lateral to the thyroid.
The overlying strap muscles (S) are located immediately anterior
to the thyroid and the sternocleidomastoid muscles (Sc) are
seen anterolateral to the thyroid.
Transverse extended-field-of-view scan shows the right
lobe of the thyroid has enlarged and extended anterior
to the common carotid artery (C).
The jugular vein (V) and the trachea (Tr) are also
Conventional transverse scan view of the right thyroid lobe
shows the thyroid (T) and the trachea (Tr).
The isthmus (I) of the thyroid is seen anterior to the trachea.
The strap muscles (S) and sternocleidomastoid (Sc) are also
seen anteriorly and laterally.
The longus colli muscle (Lc) is seen posteriorly.
The carotid (C) and jugular vein (V) are seen lateral to the
Conventional transverse view of the left thyroid lobe
shows the same structures as on the right.
In addition, the left lateral edge of the esophagus (E)
is seen posterior to the trachea. The typical bowel
layers are seen in the esophagus.
Longitudinal view of the thyroid (T) shows the lenticular
shape of the thyroid and the hyperechoic echogenicity of
the thyroid compared with the overlying strap muscles (S)
and the sternocleidomastoid (Sc).
The longus colli (Lc) is seen posteriorly.
Longitudinal power Doppler view of the
thyroid (T) shows the normal expected
degree of flow scattered throughout the
Transverse view of the thyroid shows a
normal right lobe (R) and a normal
No identifiable left lobe is present.
The trachea (T) is seen laterally.
A palpable mass
Diffuse enlargement on physical examination
A non palpable mass seen on other imaging
modality ( MRI and C.T scan )
Nodule seen on nuclear medicine scan
Abnormal thyroid function test
Detection of thyroid and other cervical
masses before and after thyroidectomy
Differentiation of benign from malignant
masses on the basis of their sonographic
FNA (biopsy) guidance
Echogenicity ( Hyper or isoechoic to normal
- peripheral eggshell ( most reliable
- large and coarse - > 2 mms
Inspissated colloid ( bright foci with comet
Entirely solid with no cystic elements.
Hypoechoic to normal thyroid.
Microcalcifications ( fine and punctate )
Associated lymph nodes w/
Peripheral hypoechoic halo
- benign - thin and regular *** found also with follicular cancers
- malignant - thick and irregular
- benign - sharp well-defined margins
- malignant - irregular or poorly defined margins
Multiplicity of nodules
- benign - multiple
- malignant - solitary nodule
*** papillary cancer is multifocal and it is uncommon for
cancer to coexist with nodular hyperplasia
Doppler flow pattern
- benign - peripheral vascularity
- malignant - internal vascularity (hyper) with or w/o
*** high sensitivity doppler instruments may significantly
Nodule size - > 1.5 cms irrespective of
physical and sonographic features
Nodule that have malignant features
Most effective method for diagnosing
malignancy in thyroid nodule
Has had a substantial impact because it
provides more direct information than any
other available diagnostic technique
- extremely common and are the most common
indication for thyroid ultrasound
Benign follicular adenomas
Follicular adenomas and follicular cancer
- same sonographic appearance
- distinguished only on the basis of vascular and capsular
- therefore FNA of follicular aspiration should generally
most common cause of thyroid nodules.
inspissated colloid is present ( 2 – 3 mms )
echogenicity is variable (hypoechoic,isoechoic,
frequently have cystic components
Large solid hyperechoic nodule (cursors) with
scattered internal regions of decreased
Solid isoechoic nodule (cursors) with a
peripheral halo and a well-defined internal
Complex cystic and solid nodule
(cursors) that simulates nodular
much more common than other types
solid hypoechoic mass or tumor
tiny microcalcifications noted
cervical lymph node metastases are
common and may contain
spread via lymphatics to nearby cervical
Transverse view shows a hypoechoic solid
lesion (cursors) that contains a few
Longitudinal view shows an entirely solid
hypoechoic lesion with scattered
microcalcifications and an irregular halo.
Longitudinal view shows a solid slightly
heteregeneous nodule (cursors) containing a
Longitudinal view shows a large complex
lesion (cursors) that is a solid but contains
large internal cystic components.
This is a follicular variant of papillary
thick, irregular halo
tortuous or chaotic arrangement of internal
vessels on color doppler
frequently coexists with multinodular
no microcalcifications and nodal metastases
spread via bloodstream
Solid hypoechoic nodule (cursors) with a
prominent internal cystic component.
appears as hypoechoic solid mass
microcalcifications are common in both
primary tumor and nodal metastases
Longitudinal view shows a solid
hypoechoic nodule (cursors). This
appearance is very similar to that of
appears as a large, solid, hypoechoic mass
extending beyond the gland and invading
adjacent structures such as the neck vessels and
not adequately examined by US because of their
Instead CT or MRI scan of the neck demonstrates
more accurately the extent of the disease
rarely seen in patients younger than 60 years old
Transverse view shows a large
lobulated solid hypoechoic
mass (cursors) replacing the
- occur as either a manifestation of generalize
lymphoma or as a primary abnormality
- usually large, solid, hypoechoic mass that
much of the thyroid parenchyma
gland is normal or enlarged with
hypoechoic,coarse and heteregeneous
common cause of hypothyroidism
also called chronic autoimmune lymphocytic
heteregeneous texture-thin echogenic fibrous
strands present causing to have a multilobulated
or micronodular appearance
Longitudinal view shows an enlarged
thyroid that is diffusedly heteregeneous
and more hypoechoic than normal
Longitudinal view shows a thyroid that is
hypoechoic and heteregeneous with several
confluent areas of decreased echogenicity
Longitudinal view shows a thyroid that has
decreased echogenicity and several more
hypoechoic fibrous strands dispersed in
an irregular fashion.
Transverse view of the thyroid shows diffuse
heterogenecity and decreased echogenicity with
two discrete hyperechoic nodules (cursors).
Fine-needle aspiration confirmed that these
nodules were also due to Hashimoto’s thyroiditis.
Longitudinal power Doppler view shows
marked hypervascularity throughout the
• Ectopia – usually diagnosed with nuclear medicine
• Thyroglossal duct cysts
– most common of the congenital cysts
Appear as cystic lesions with low-level
intraluminal reflectors, presumably due to
bleeding or infection.
Usually do not appear as simple cysts.
Most common of the congenital cysts in the
Located in the midline between the thyroid
gland and the hyoid bone.
Longitudinal view of the midline of the neck in the
suprathyroidal region shows the hyoid bone (H) and the
thyroid cartilage (T) their associated shadows.
A complex cystic lesion (cursors) with diffuse low-
level echoes is seen located immediately between
these two structures.
This is the typical location for a thyroglossal duct cyst.
Transverse view of the midline neck in the
suprathyroidal region shows a complex cystic lesion
(cursors) with low-level echoes and a thin septation
Transverse view of the neck above the level of the
thyroid gland shows the thyroid cartilage
(arrowheads), extending from the midline over the left
is a complex cystic lesion (cursors) consistent with a
Longitudinal view of the right lobe of the thyroid shows a
slightly lobulated solid predominantly hypoechoic nodule
This patient had a history of melanoma and fine-needle
aspiration confirmed metastatic melanoma to the thyroid.