2. ANATOMY
Embryology
• Develops from endodermal cells
of the floor of the pharynx
(thyroglossal duct )
• The duct descends downward in
the neck in front of hyoid bone
• Distal end forms the thyroid gland
3. •Location - lower anterior neck in infrahyoid compartment
•Boundary - Straps muscles anteriorly and
2nd and 4th tracheal ring and longus colli muscle posteriorly
•Gland is made up of 2 lobes and joined in midline in front of trachea by
thin bridge of thyroid tissue called isthmus
•An accessory lobe ( pyramidal lobe) may be present in 10 -40 % of normal
population . It originates from isthmus or medial aspect of either lobes
and extends superiorly.
•Arterial supply : paired sup and inf thyroid arteries
•Venous drainage : sup , middle and inf thyroid veins
ANATOMY
4. • First choice for evaluation of thyroid morphology
• Supine position with neck mildly hyperextended
• High frequency linear array transducers ( 7.5- 15 MHz)
• Examined in both transverse and longitudinal planes.
• Should extend laterally to include the region of carotid artery and
jugular vein (jugular chain lymphnodes) , superiorly to visualize
submandibular adenopathy and inferiorly for pathologic
supraclavicular lymphnodes.
5. • Normal thyroid parenchyma has a homogenous medium to high level
echoes
• Capsule : Thin hypoechoic line that bounds the thyroid lobes
• Dimensions:Longitudinal :40-60 mm
Anteroposterior :13 -18 mm (most precise and fairly constant)
Isthmus : 4-6mm
6. Doppler
• Superior thyroid artery and vein- upper pole of each lobe
• Inferior thyroid vein at lower pole
• Inferior thyroid artery -posterior to the lower third of each lobe
• Normal PSV in major
thyroid arteries 20 -40 cm/sec
and 15-30 cm/sec in
intraparenchymal arteries
9. DIFFUSE THYROID DISEASE
DIFFUSE NONTOXIC GOITRE
• Diffuse, non nodular enlargement of the thyroid associated with a
euthyroid state
• USG : diffuse enlargement with uniform or variable echogenicity
10. • Most common autoimmune disorder
• USG : diffusely enlarged thyroid gland with smooth lobular contour
• Echotexture is homogenous , but patchy areas of altered echotexture
may be present (due to numerous ,large intraparenchymal vessels)
• Iso – hypoechoic parenchyma ( because of extensive lymphocytic
infiltrate)
• Colour doppler: Hypervascular pattern “ thyroid inferno” (indicating acute
stage)
• Spectral doppler: PSV > 70cm/sec ( highest velocity found in thyroid
disease)
• Doppler analysis can be used to monitor the therapeutic response in pts
with graves disease . Significant decrease in flow velocities in thyroid
arteries is seen.
DIFFUSE TOXIC GOITRE ( GRAVES DISEASE )
11. Mildly enlarged right
lobe of thyroid
Significantly increased
intraglandular
vascularity : Thyroid
inferno
Spectral doppler
showing markedly
increased PSV
12. • Diffuse , coarsened parenchymal echotexture, more hypoechoic than normal
thyroid
• Micronodulation : multiple discrete hypoechoic nodules 1-6 mm in diameter . (
Highly sensitive sign )
• Pseudolobulated appearance : Lobules surrounded by multiple linear echogenic
fibrotic septation
• Cervical lymphadenopathy
• Colour doppler : vascularity may be normal , increase (acute stage) or decrease .
CHRONIC AUTOIMUNNE LYMPHOCYTIC THYROIDITIS
( HASHIMOTO’S )
13. Both benign and malignant nodules may coexist with chronic lymphocytic
thyroiditis and FNA is often necessary to establish the diagnosis
Usg is used for follow up to detect occult malignancy , because there is
increased risk of malignancy of non Hodgkin lymphoma of thyroid
Features suspicious of malignancy in Hashimoto's:
• Large or infiltrating hypoechoic nodule
• Nodule with microcalcification
• Cervical lymphadenopathy
CHRONIC AUTOIMUNNE LYMPHOCYTIC THYROIDITIS
( HASHIMOTO’S )
15. Diffusely enlarged right and left lobe
with linear echogenic sepatations
Hashimoto’s thyroiditis
with hyperplastic
enlarged lymphnode
16. USG
• Ildefined
• hypoechoic
• heterogenous mass with internal debris with or without septa or gas
• Adjacent inflammatory nodes
ACUTE SUPPURATIVE THYROIDITIS
17. Ultrasonography of the left lobe of the thyroid gland.
(A)On admission, multiple pre existing multigoiter nodules (asterisks) with a round,
hypoechoic lesion with heterogeneous internal echogenicity
This lesion lacked a distinct capsule and measured approximately 26 × 22 mm in diameter.
(B) Ultrasonography on day 6. The hypoechoic lesion increased in size (29 × 27 mm),
and decreased in internal echogenicity
(C) Ultrasonography 1 month after discharge. Decreased size of the hypoechoic lesion
(17 × 15 mm).
18. • Nodular thyroid disease is characterized by presence of one or more
palpable or non palpable nodules within the thyroid gland
• Approx 80 -85 % of nodular thyroid disease is due to hyperplasia of
the gland
• Hyperplastic nodule undergoes liquefactive degeneration resulting in
accumulation of colloid substance ( Colloid Nodule )
NODULAR THYROID DISEASE
21. MULTINODULAR GOITRE
• Most Common benign pathology of the thyroid
• Defined as enlarged thyroid gland due to multiples nodules which
may have normal ,increased or decreased function.
USG
• Enlarged thyroid gland with multiples nodules of different sizes
• Most hyperplastic or adenomatous nodules appear as isoechoic with
thin peripheral hypoechoic halos
• Less commonly a sponge like or honeycombing pattern is also seen
22. • Colloid or Serous fluid collection appears purely anechoic
• Echogenic fluid or moving fluid-fluid levels corresponding to haemorrhage.
• Bright echogenic foci with comet-tail artifacts are likely caused by
microcrystals or aggregates of colloid substance.
• Thin, intracystic septations
• Eggshell calcification may be seen
MULTINODULAR GOITRE
24. ADENOMA
• Most are soliditary , but may present as multinodular disease
USG
• Appear as solid masses that may be hyperechoic, isoechoic, or hypoechoic.
• They often have a thick, smooth peripheral hypoechoic halo (due to fibrous
capsule and blood vessels)
• Color Doppler imaging: “Spoke and wheel” appearance (vessels passing
from the periphery to the central regions of the nodule). This vascular
pattern is seen in both hyperfunctioning and poorly functioning adenomas
and thus does not allow the detection of hyperfunctioning lesions.
26. CARCINOMA
Papillary carcinoma
USG
• Hypoechogenicity (90% of cases), resulting from closely packed cell
content, with minimal colloid substance.
• Microcalcifications, appearing as tiny, punctate hyperechoic foci, either
with or without acoustic shadows.
• In rare, but aggressive cases of papillary carcinomas of childhood,
microcalcifications may be the only sonographic sign of the neoplasm, even
without evidence of a nodular lesion
• Hypervascularity (90% of cases)
27. • Cervical lymph node metastases: Located in the caudal half of the
deep jugular chain.
• Contain tiny, punctate microcalcifications. Occasionally, nodes may be
cystic ( due to extensive degeneration)
• Invasion of adjacent muscles.
PAPILLARY CARCINOMA
28. • Rare, nonencapsulated sclerosing tumor measuring 1 cm or less in
diameter.
• Mc presentation enlarged cervical nodes with palpably normal
thyroid gland.
USG
• Small , hyperechoic patch under the capsule with thickening and
retraction of the capsule
• Minute hypoechoic nodule with blurred irregular outline
• Intense vascularity within and around the lesion.
Papillary microcarcinoma
29. Hypoechoic nodule with micro
calcification
Extremely Hypoechoic nodule
without calcification
31. Heterogeneous but isoechoic mass in the
isthmus (arrows) that contains
microcalcifications and thick, irregular halo
Hypoechoic solid nodule with thick,
irregular halo and linear calcifications at
anterior margin (arrow).
32. B) Power Doppler image shows that
nodule is hyper- vascular and has flow
in the center and at the periphery.
A) Longitudinal image shows 1.5-cm
nodule with a thick, irregular halo.
33. C) Longitudinal image shows hypoechoic
nodule with microcalcifications.
D) Power Doppler image shows no blood
flow within the cancer.
34. A) Transverse images near the carotid artery
(C) and jugular vein (J) show small, round,
hypoechoic lymph nodes (arrows)
B) Despite their small size (~4 mm), the round
shape and the hypoechoic appearance are
highly indicative of metastasis.
Heterogeneous lymph nodes containing
calcification (arrows)
35. Longitudinal image shows a
large lymph node (arrows)
containing cystic change.
Cystic change in a cervical
lymph node is almost always
caused by metastatic papillary
carcinoma.
36. FOLLICULAR
• USG appearance is similar to adenoma (because of cytologic and
histologic similarities between these tumors).
• Fine-needle aspiration is not reliable in differentiating benign
from malignant follicular neoplasms as the pathologic diagnosis
is not based on cellular appearance but on capsular and vascular
invasion.
• Therefore, most follicular nodules must be surgically removed for
accurate pathologic diagnosis.
37. Features that suggest follicular carcinoma are :
• Irregular tumor margins
• Thick irregular halo
• Color Doppler : tortuous or chaotic arrangement of internal blood
vessels
38. Round homogenous hypoechoic mass
in left lobe of thyroid
Right lobe of the thyroid showing round,
homogeneous hypoechoic masses
Follicular Carcinoma Adenoma
39. MEDULLARY CARCINOMA
• Derived from the parafollicular cells, or C cells
• Secretes calcitonin, which can be a useful serum marker.
• It is frequently familial (20%) and is an essential component of the
multiple endocrine neoplasia (MEN) type II syndromes
• The sonographic appearance is usually similar to that of papillary
carcinoma and is seen as a hypoechoic solid mass.
• Calcifications are often seen in the tumor and also in lymph node
metastases. They tend to be more coarse than the calcifications of typical
papillary carcinoma.
40. Patient with multiple endocrine neoplasia type II (MEN II) showing
bilateral hypoechoic masses (arrows) containing areas of coarse calcification
41. LYMPHOMA
• Approximately 4% of all thyroid malignancies.
• It is mostly of the non-Hodgkin’s type and usually affects older women.
• In 70% to 80% of patients, lymphoma arises from a preexisting chronic
lymphocytic thyroiditis (Hashimoto’s thyroiditis)
• The typical clinical sign is a rapidly growing mass causing dyspnea or
dysphagia
42. • Extremely hypoechoic and lobulated
mass.
• Large areas of cystic necrosis with
encasement of adjacent neck vessels
may be seen
• The adjacent thyroid parenchyma may
be heterogeneous( due to associated
chronic thyroiditis)
• On Color Doppler imaging :
Hypovascular.
USG
Transverse image of left lobe of the thyroid shows diffuse mass
enlarging the lobe and extending into the soft tissues (arrows)
surrounding the common carotid artery (c);
43. DIFFERENTIATION OF BENIGN AND MALIGNANT THYROID
NODULES
• According to several reports, for the differentiation of benign versus
malignant thyroid nodules, sonography has sensitivity rates of 63% to
94%, specificity of 61% to 95%, and overall accuracy of 78% to 94%.
44. CATEGORY BENIGN MALIGNANT
SHAPE WIDER THAN TALL TALLER AND WIDE
MARGIN SMOOTH, WELL DEFINED , ILLDEFINED SPICULATED ,ILLDEFINED
ECHOGENECITY HYPERECHOIC , ISOECHOIC MARKEDLY HYPOECHOIC
COMPOSITION CYSTIC , PREDOMINANTLY CYSTIC ,
SPONGIFORM
MIXED CYSTIC AND SOLID, SOLID OR
ALMOST COMPLETELY SOLID
HALO THIN THICK , INCOMPLETE OR ABSENT HALO
ECHOGENIC FOCI/ CALCIFICATION COMET TAIL ARTEFACTS (COLLOID
CYST), EGG SHELL CALCIFICATION
MACROCALCIFICATION,
MICROCALCFICATION
VASCULARITY PERIPHERAL INTRANODULAR
45. TIRADS
• Thyroid nodules are exceedingly common, leading to costly
interventions for many lesions that ultimately prove benign.
• In response, ACR committees were formed to accomplish three goals:
• Develop management guidelines for nodules that are discovered
incidentally on CT, MRI, PET or ultrasound
• Produce a lexicon to describe all thyroid nodules on sonography
• Develop a standardized TI-RADS risk-stratification system based on
the lexicon to inform practitioners about which nodules warrant
biopsy
46. ACR TIRADS
• Published in 2017
• ACR TI-RADS is a reporting system for thyroid nodules on ultrasound
proposed by the American College of Radiology (ACR) 1
• This uses a standardised scoring system for reports providing users with
recommendations for when to use fine needle aspiration (FNA) or
ultrasound follow-up of suspicious nodules, and when to safely leave alone
nodules that are benign/not suspicious.
• It uses a point-based system, awarding points for all the ultrasound
features of a nodule (five lexicon categories in total), with more points
awarded to the most suspicion categories. The total points of a nodule is
used to determine the TI-RADS level, ranging from TR1 (benign) to TR5
(highly suspicious for malignancy)
47.
48. • If rim calcifications obscure the nodule completely, choose
composition to be “solid” and echogenicity to be “isoechoic”
• If the margin cannot be determined, choose “ill-defined ‘’
• If echogenicity cannot be determined, choose ‘’isoechoic’’
• If composition cannot be determined, choose “solid”.
ASSUMPTION
50. Composition: Spongiform
Composed predominately of tiny cystic spaces. (at least
50% of the nodule’s volume should be occupied by tiny
cysts)
Spongiform is a benign finding.
If there is concern for irregular margins or suspicious
echogenic foci,
reconsider your choice of spongiform.
58. Shape: Taller-than-wide
A taller-than-wide shape is defined as a ratio of >1 in the anteroposterior diameter
to the horizontal diameter when measured in the transverse plane
59. Shape: Wider-than-tall
A wider-than-tall shape (not taller-than-wide) is defined as a ratio of ≤1 in the
anteroposterior diameter to the horizontal diameter when measured in the transverse
plane.
62. Margin: Irregular
The outer border of the nodule is spiculated,
jagged, or with sharp angles with or without
clear soft tissue protrusions into the
parenchyma.
The protrusions may vary in size and
conspicuity and may be present
in only one portion of the nodule
63. Margin: Lobulated
Border has focal rounded soft tissue protrusions that extend into the adjacent
parenchyma.
The lobulations may be single or multiple and may vary in conspicuity and size
(small lobulations are referred to as microlobulated)
65. Echogenic Foci: Large Comet Tail
A comet-tail artifact is a type of reverberation
artifact.
The deeper echoes become attenuated and are
displayed as decreased width,resulting in a
triangular shape.
67. Echogenic Foci: Peripheral Calcifications
Calcifications occupy the periphery of the nodule.
May not be continuous but generally involves the
majority of the margin.
Often dense enough to obscure the central components
of the nodule (see Assumptions).
68. Echogenic Foci: Punctate Echogenic Foci
“Dot-like” foci less than 1 mm in diameter. Occasionally can have small comet tail artifacts
69. The main reporting and practical considerations are:
• Measurement - Three axes diameter (including the nodule halo, if
present).
• Location - Right, Left, Isthmus, Upper, Mid, Lower, and, if necessary,
Lateral, Medial, Anterior or Posterior)
• Description of a maximum of four nodules - Highest TI-RADS score that fall
in the size threshold for FNA.
• Definition of growth - 20% increase in two nodule dimensions and a
minimal increase of 2 mm.
• Maximum nodules to biopsy - No more than two nodules with the highest
TIRADS point total that meet criteria for FNA.
• Cervical lymph node involvement - Ultrasound evaluation is fundamental
and FNA of suspicious nodes should be done, in to thyroid nodule FNA.
70. Template For Reporting
Nodule number 1
Location : Left upper
Composition : Solid
Echogenecity : Hypoechoic
Shape : Wider-than-tall
Margin : lobulated
Echogenic foci : punctuate
echogenic foci
Size : 1.2 x 1.1 x 0.9 cm
Total Points : 9
ACR TIRADS category : TR5
71. CATEGORIES US FEATURES FNA RECOMMENDATION
EU -TIRADS 1 : NORMAL NO NODULES
EU - TIRADS 2 : BENIGN CYST , SPONGIFORM Not indicated unless
compressive symptons
EU – TIRADS 3 : LOW RISK OVOID , SMOOTH , ISOECHOIC/
HYPERECHOIC . No features of
High Suspicion
Proceed to FNA if more than
20mm.
EU – TIRADS 4 : INTERMEDIATE
RISK
OVOID , SMOOTH MILDLY
HYPOECHOIC. No features of
High Suspicion
Proceed to FNA if more than
15mm.
EU – TIRADS 5 : HIGH RISK Atleast 1 of the following
features of high suspicion:
- Irregular shape
- Irregular margin
- Microcalcification
- Marked hypoechogenecity
Proceed to FNA if more than
10mm.
EUROPEAN TIRADS (EU TIRADS)
72.
73. Difference between ACR - TIRADS and EU - TIRADS
ACR TIRADS EU TIRADS
Normal Gland EU TIRADS 1
Benign (
Cystic/Spongiform)
TR1 EU TIRADS 2
Not suspicious
(mixed cystic/solid)
TR2 -
Mildly suspicious/
low risk
TR3 EU TIRADS 3
Moderately
suspicious /
intermediate risk
TR4 EU TIRADS 4
Highly suspicious /
High risk
TR5 EU TIRADS 5
74. • EU-TIRADS It is a system that assigns each lesion into a risk group according
to the presence of certain US findings.
• ACR-TIRADS is a score-based system, according to the US features of a
given nodule.
• EU-TIRADS 2 means a benign nodule, and ACR-TIRADS 2 means a non-
suspect nodule. Both of them have distinct US characteristics. EU-TIRADS 2
is the equivalent to ACR-TIRADS 1.
• In EU-TIRADS, the threshold to perform FNA are 2cm (low risk - EU-TIRADS
3), 1.5cm (intermediate risk - EU-TIRADS 4) and 1cm (high risk - EU-TIRADS
5).
• In ACR-TIRADS, the threshold size to perform a FNA are 2.5cm (TR3), 1.5cm
(TR4) and 1 cm (TR5).
• Respecting the multinodular disease, the recommedation is to report at
least the 3 nodules with highest TIRADS (EU-TIRADS) and a maximun of 4
(ACR-TIRADS).
75. REFERENCES
• Diagnostic Ultrasound 4th Edition Carol M. Rumack , Stephanie
Wilson, Deborah Levine
• Grainger and Allison Diagnostic Radiology 6th edition
• Tessler, F. N., Middleton, W. D., Grant, E. G., Hoang, J. K., Berland, L. L.,
Teefey, S. A., … Stavros, A. T. (2017). ACR Thyroid Imaging, Reporting
and Data System (TIRADS): White Paper of the ACR TI-RADS
Committee. Journal of the American College of Radiology, 14(5), 587-
595.
• Thyroid Imaging Reporting and Data System (TI-RADS): A User’s Guide
Franklin N. Tessler, William D. Middleton Edward G. Grant.
