The document discusses the Thyroid Imaging Reporting and Data System (TIRADS) which was developed to standardize the ultrasound reporting of thyroid nodules and stratify the risk of malignancy. It describes the original TIRADS classification proposed by Horvath et al. and modifications made by Kwak et al. Kwak et al's simplified classification categorizes nodules based on the number of suspicious ultrasound features present into TIRADS 3, 4a, 4b, 4c, and 5 risk groups. A later study by Fernández Sánchez further modified the scoring system to assign a point for each suspicious feature and lymph node observed on ultrasound.

1. TIRADS
Thyroid Imaging Reporting And
Data System

2. • Thyroid nodules are highly prevalent; about one third
of the adult population has thyroid nodules on
ultrasonographic examination.
• However, less than 10% of them are malignant[1,2].
• 1. Papini E, Guglielmi R, Bianchini A, Crescenzi A, Taccogna S, Nardi F, PanunziC, Rinaldi R, Toscano V,
PacellaCM2002 Risk of malignancy in nonpalpable thyroid nodules: predictive value of ultrasound and color-
Doppler features.J Clin Endocrinol Metab 87:1941–1946
• 2. Koike E, Noguchi S, Yamashita H, Murakami T, Ohshima A, Kawamoto H,Yamashita H 2001
Ultrasonographic characteristics of thyroid nodules: predictionof malignancy. Arch Surg 136:334–337.

3. • The terminology of TIRADS was first used by Horvath
et al .
• BI-RADS was taken as a model.
• The goal was to group thyroid lesions in different
categories with a percentage of malignancy similar to
those accepted in the BI-RADS.

4. • During stage I (from 2000–2001), US findings of 362 thyroid
nodules were reviewed to define and specify their
characteristics and establish 10 US patterns –
• Echostructure.
• Echogenicity.
• Shape.
• Orientation.
• Acoustic transmission.
• Borders.
• Surface.
• Presence or absence of a capsule, calcifications, and
vascularization.

5. • At the second stage (from 2002–2003), the group
prospectively correlated the FNAB results of another
set of 500 nodules with the defined US patterns and
generated a TIRADS group classification .

6. • TIRADS 1: normal thyroid gland.
• TIRADS 2: benign conditions (0% malignancy).
• TIRADS 3: probably benign nodules (5% malignancy).
• TIRADS 4: suspicious nodules (5–80% malignancy rate).
4a (malignancy between 5 and 10%) and
4b (malignancy between 10 and 80%) .
• TIRADS 5: probably malignant nodules (malignancy >80%).
• TIRADS 6: category included biopsy proven malignant
nodules.

7. • In stage 3 (from 2003–2006), the group
prospectively validated the TIRADS evaluating
1097 additional selected nodules.
• Table shows the US characteristics for each
TIRADS group ---

9. US image of multiple typical colloid cysts: anechoic areas with
hyperechogenic spots (type 1 colloid pattern).
TIRADS 2

11. type 2 colloid nodule:
a mixed, nonexpansile, nonencapsulated structure with a “grid”
appearance given by isoechoic solid areas and hyperechoic
spots. The gland is not enlarged.
TIRADS 2

13. colloid type 3 pattern: a mixed, nonencapsulated, expansile,
isoechoic nodule with hyperechoic spots and broad septa.
TIRADS 2

15. US aspect of Hashimoto thyroiditis with a pseudo-nodule: normal size
heterogeneous gland with lobulated borders and a hyperechoic pseudo-nodule
(arrow), partially surrounded by a halo.
TIRADS 3

17. US image of a simple neoplastic pattern : E -- a solid hyperechoic nodule without
calcifications, surrounded by a thin capsule.
F, A hypoechoic area with ill-defined borders, without calcifications.
TIRADS 4 A.

19. US image of a suspicious neoplastic pattern (4B):
an encapsulated heterogeneous nodule with coarse calcifications,
surrounded by a thick capsule.
TIRADS 4B

21. US image of malignant pattern A: TIRADS 4 B suspicious.
Solid hypoechoic, irregular nodules with ill-defined margins, with
calcifications (thin arrow) or without calcifications (thick arrow).

23. US image of malignant pattern B: TIRADS 5
solid, nonencapsulated, isoechoic, ill-defined nodule with a “salt
and pepper” aspect, due to peripheral microcalcifications.

24. US image of malignant pattern C: TIRADS 6
a mixed, isoechoic, vascularized, nonencapsulated nodule with
calcifications and no hyperechoic spot.

26. • FNAB is the best tool in helping to decide between nodules
that require surgery and those that can be followed.
• One of the limitations of FNAB is the indeterminate or
follicular lesion

27. • However, performing FNAB in all nodules is not cost effective;
• It is necessary to select cases according to the risk of
malignancy.
• The TIRADS classification is useful in the description of all
types of US-detected lesions, including both benign nodules
and follicular lesions.
• Patients with TIRADS 2 (benign findings) do not require FNAB.

28. • TIRAD 3 lesions should be followed; some of these patients
are biopsied when clinically warranted:
1. If the nodule grows during follow-up,
2. The patient is not able to come back for regular follow-up
checkups,
3. Patients with higher risk of malignancy -those exposed to
previous radiation to the neck,
4. Those with family history of thyroid cancer.

29. • TIRADS 4 and 5 nodules must be biopsied, and
frequently are operated on.

30. • The terminology of TIRADS was first used by Horvath et al .
• They described 10 US patterns of thyroid nodules and related
the rate of malignancy according to the pattern.
• However, these US patterns were not applicable
to all thyroid nodules and this stereotypic US application is
difficult for US performers to use.
Therefore, it is not easy to apply this kind of approach to clinical
practice.

31. • Park et al proposed an equation for predicting the probability
of malignancy in thyroid nodules on the basis of 12 US
features.
• Although this approach makes it possible to stratify nodules
into categories, it can be difficult to assign every thyroid
nodule into the equation proposed in clinical practice.

32. • Although previous investigators have tried to develop
a thyroid imaging reporting and data system
(TIRADS), the systems were difficult to apply in the
clinical field because of their complexity.

33. • The classification by Kwak et al is simple and similar
to BIRADS.
• Their aim was to develop a practical TIRADS with
which to categorize thyroid nodules and stratify their
malignant risk.

34. • Several US features, such as ---
 Internal component,
 Hypoechogenicity, marked hypoechogenicity,
 Microlobulated or irregular margins,
 Microcalcifications, and
 Taller-than-wide shape,
were regarded as independent US features of
malignancy

35. • Internal component of the nodules was
classified as –
1. Solid .
2. Mixed solid.
3. Cystic.

36. • Echogenicity -
1. Hyperechogenicity,
2. Isoechogenicity,
3. Hypoechogenicity - echogenicity was less than
that of the surrounding strap muscle.
4. Marked hypoechogenicity.

37. a
<p>US scans show features indicative of malignancy, including (a) hypoechogenicity (☆ = strap muscle, arrows = nodule); (b)

38. • Margins –
1. Well circumscribed,
2. Microlobulated – the presence of many small
lobules on the surface of a nodules.
3. Irregular.

39. <p>US scans show features indicative of malignancy,
(d) irregular margin (arrows = nodule).</p>
"

40. • Calcifications -
1. Microcalcifications - equal to or less than 1
mm in diameter and visualized as tiny
punctate hyperechoic foci +/- acoustic
shadow.
2. Macrocalcifications- hyperechoic foci larger
than 1 mm.

41. <p>US scans show features indicative of malignancy, includin
microcalcifications (arrows);

42. • Shape –
1. Taller than wide (greater in its antero-posterior
dimension than in its transverse dimension).
2. Wider than tall.

43. <p>US scans show features indicative of malignancy,
(c) marked hypoechogenicity (☆ = strap muscle, arrows = nodule), microlobulated margin, and taller-than-wide shape

44. • The following US features are significantly associated with
thyroid cancer: solid component, Hypoechogenicity, marked
hypoechogenicity, microlobulated or irregular margins,
microcalcifi cations, and taller-than-wide shape.
• Nodules showing at least one of the suspicious findings were
considered suspicious for malignancy.
• As the number of suspicious US features increased, the
probability and risk of malignancy also increased.

45. • TIRADS –
• 3 (no suspicious US Features).
• 4a (one suspicious US feature),
• 4b (two suspicious US features),
• 4c (three or four suspicious US features),
• 5 (five suspicious US features).

47. • Because thyroid neoplasias are slowly growing tumors , a long
follow-up period is necessary to consider a nodule as benign
in patients not undergoing thyroidectomy.
• Therefore, we may have to accept the stability of the US
findings and FNAB for a period of at least 4–5 yr as an
indicator of a benign nodule in those patients that are being
followed.

48. • The TIRADS classification and the FNAB are
complementary procedures. The TIRADS is only a
tool used to select high-risk nodules for FNAB.
• Risk stratification of thyroid malignancy by using the
number of suspicious US features allows for a
practical and convenient TIRADS.

49. THANK YOU

50. • In 2009, Horvath et al proposed a classification known as TI-
RADS and later Kwak et al added a subtype (4c).
• However, not all the ultrasound features of nodules proposed
by Horvath et at can be applied with certainty in daily
practice.
• As regards Kwak et al, they did not use TN perfusion on color
Doppler within their classification.

51. • TI-RADS classification of thyroid nodules based on a score
modified according to ultrasound criteria for malignancy J.
Fernández Sánchez . Rev. Argent. Radiol. 2014;78(3): 138-148.
• This study also assessed the presence of suspicious cervical
lymph nodes (differentiating them from Kwak classification as
regards the evaluation criteria for scoring).

52. • They propose a TI-RADS classification based on a scoring
system in which each ultrasound abnormality suspicious for
malignancy is assigned a score.
• If one or more cervical lymph nodes suspicious for malignancy
are detected, an additional point is added.

53. TI-RADS classification of thyroid nodules based on a scoring system according to
ultrasound criteria for malignancy.

54. Sonographically suspicious criteria for malignancy.
Each criterion is assigned a point in the final score.
If suspicious cervical lymph nodes are detected, an
additional point is added to the score for categorizing
nodules on TI-RADS classification.

55. • In this study, 4.7% of thyroid ultrasound scans did not show
focal lesion and the thyroid gland showed a hyperechoic,
homogeneous and normal ultrasound pattern with no
changes in vascularity.
• These cases constituted category 1 in TI-RADS classification .

56. TI-RADS 1: normal thyroid gland.

57. • 35.6% of TNs with well-defined criteria for benignity
(simple cyst, solid nodule with central cyst, nodule
with homogeneous peripheral calcification and
spongiform nodule), with benignity being confirmed
by various methods , were classified as TI-RADS 2.

58. TI-RADS 2: simple thyroid cyst.
solid nodule with central cyst.

59. nodule with homogeneous peripheral
calcification
spongiform nodule.

60. • Only 2.2% of TNs with peripheral vascularity and hyperechoic (with
or without cystic changes) or diverse US pattern (hypo, iso or
hyperechoic, with cystic changes and/or macrocalcifications) proved
to be malignant.
• These TNs with a score of 1 and probably benign US findings are
classified as TI-RADS 3 (probability of malignancy < 5%) according
to Horvath et al and Kwak et al.
• In this respect, it should be noted that many of the TI-RAD 3
nodules are functioning or toxic thyroid adenomas and that
malignancy within this category is not only a rare occurrence, but
also a generally unexpected histological finding following nodular
goiter surgery .
• In our study, 9.5% of TNs meeting one criterion for malignancy were
diagnosed as thyroid carcinoma.

61. hyperechoic nodule
slightly hyperechoic nodule with small
cysts and peripheral vascularity

63. Patient with nodular goiter. In a hyperechoic nodule with small cysts, consistent
with TI-RADS 3, a small papillary thyroid carcinoma (pT1b) was histologically
detected after surgery

64. • TNs with a score of 1 were assigned category 4a in TI-RADS
classification .
• While TNs with a score of 2 were classified as TI-RADS 4b.
• In the latter case, the incidence of malignancy increased up
to 48%.
• In turn, TNs with a score of 3 or 4 showed an increased
incidence of thyroid carcinoma of up to 85%, and were
therefore included within TI-RADS 4c . In this category, Kwak
et al6 report a probability of malignancy of 50-95%.

65. Sonographically suspicious criteria for malignancy. Each
criterion is assigned a point in the final score.
If suspicious cervical lymph nodes are detected, an
additional point is added to the score for categorizing
nodules on TI-RADS classification.

66. TI-RADS4a: markedly hypoechoic nodule, of normal shape
and abnormal vascularity. Score of 1.

67. TI-RADS 4b: nodule with microcalcifications and poorly
defined irregular margins. Score of 2.

68. TI-RADS 4b: nodule with two sonographically
suspicious criteria for malignancy:
hypoechogenicity and internal vascularity.

69. TI-RADS 4c: nodule with microcalcifications, irregular borders and taller than
wide shape (greater in its anteroposterior diameter than in its transverse
diameter). Score of 3.

70. TI-RADS 4c: hypoechoic nodule of irregular margins with a
taller than wide shape. Score of 3.

71. • TNs with a score of 5 or higher were classified as TI-
RADS 5 .
• In this study, all TNs with these ultrasound features
proved to be malignant, but Horvath et al3 and Kwak
et al6 report for this category a probability of
malignancy of 85-99%.

72. TI-RADS 5: hypoechogenic nodule with microcalcifications and poorly
defined margins, with perinodular tissue invasion (arrow). Taller than
wide shape.

73. Continued . ... TI-RADS 5: suspicious hypoechoic lymph node, with round
shape and abnormal vascularity. Overall score of 6 for the nodule.

75. • Based on the criteria for malignancy and the score assigned in
this study, the probability of malignancy for TNs with a score
of 1 ( 4 A) is 10%, while for those with a score of 2 ( 4 B) is
almost 50% and for those that have been assigned a score of 3
or 4 ( 4 C) , the probability of malignancy is 85%.
• All TNs with a score of 5 or higher are malignant.
• A TI-RADS classification based on the scoring system
described above should allow for and lead to unification of
terminology and codes for TN classification among all
physicians who evaluate the results of a thyroid ultrasound .

76. • Chandramohan A, Khurana A, Pushpa B T, Manipadam MT,
Naik D, Thomas N, Abraham D, Paul MJ. Is TIRADS a practical
and accurate system for use in daily clinical practice?. Indian J
Radiol Imaging 2016;26:145-52.

77. • Of all the systems, the classification proposed by
Kwak et al. is simple and similar to BIRADS system
which has been in use for many years and is familiar
to most radiologists.
• Therefore, we aimed to assess the PPV and
inter-observer agreement of TIRADS as proposed by
Kwak et al.

78. Ultrasound features assessed for each nodule were :-
• composition (solid, cystic, mixed),
• echogenicity (hyperechoic, isoechoic, hypoechoic,
markedly hypoechoic).
• margins (well defined with or without halo sign,
microlobulated, ill-defined,irregular).
• presence of calcification (microcalcification,
macrocalcification).
• shape of the nodule (round, oval).

79. COMPOSITION –
• Nodules with >75% solid component were labelled as solid;
• Cystic nodules had no solid components .
• Mixed nodules had both solid and cystic areas with solid
component constitution <75% of the size of the lesion.
• For mixed lesions, echogenicity, margin, shape, and presence
of calcification were assessed for the solid component.

80. (A) cystic (B) solid and (C) mixed composition of thyroid nodules

81. Echogenicity was described in comparison with the thyroid gland
and the strap muscles.
• Hyperechoic if the echogenicity > that of thyroid gland.
• Isoechoic if the echogenicity = that of thyroid gland,.
• Hypoechoic if the echogenicity = that of strap muscle.
• Markedly hypoechoic if the echogenicity < than that of strap
muscle.

82. (A) hyperechoic. (B) isoechoic (C) hypoechoic and (D) markedly hypoechoic thyroid nodules

83. MARGINS --
• Hypoechoic smooth rim around the nodule was considered as
a positive halo sign.
• Presence of short cycle undulations of more than three along
the margin of the nodule was considered as microlobulated
margin.
• Spiculated margins were considered as irregular.
• Fuzzy margins were considered ill-defined.

84. (A) well-defined (B) microlobulated (C) ill-defined and (D) irregular thyroid nodules

85. CALCIFICATION –
• Calcification that measured less than 1 mm was
defined as microcalcification.
• Calcification more than 1 mm was labelled as
macrocalcification.

86. (A) microcalcification and (B) macrocalcification in thyroid nodules

87. SHAPE –
• The shape was described as round or “taller than
wide” if the antero-posterior dimension was equal to
or greater than the transverse dimension.
• A nodule which was “wider rather than” tall was
described as an oval nodule.

88. (A) Oval and (B) taller than wide shaped thyroid nodules

89. Findings that were considered in favor of a malignancy
were –
• Hypoechoic or markedly hypoechoic in echogenicity;
• Irregular, mcrolobulated or ill-defined margins.
• Presence of microcalcification;
• Round shape.

90. • Completely cystic thyroid nodule, nodules with comet tail
artifacts, and spongiform thyroid nodules ----TIRADS
category 2.
• Solid, oval, well-defined, isoechoic nodules ---- TIRADS
category 3.
• Nodules were assigned TIRADS categories 4a, 4b, 4c, and 5
if they had one, two, three, and more than three suspicious
ultrasound features, respectively.
• Presence and absence of significant neck nodes
(hypoechoic, round nodes with calcification or necrosis
irrespective of their size) and the pattern of vascularity of
the nodules were also documented, though they were not
a part of TIRADS.

92. Comparison of diagnostic performance of the various ultrasound classification systems
available to assess thyroid nodules

93. • There was improvement in the PPV (from 64% to 75%) and
specificity (from 69% to 85.5%) when TIRADS category 4a
nodules were reassigned to category 3;
• However, sensitivity of TIRADS reduced (from 72% to 60%).
• In the actual clinical setting, it may be practical to follow-up
patients with just one suspicious feature and indeterminate
cytology than subjecting them to surgery.

94. • Of the 112 malignant thyroid nodules, 34 (30.3%) were a
follicular variant of papillary cancers which have a relatively
benign ultrasound appearance.
• In conclusion, the PPV for malignancy was high for TIRADS
category 5 and 4c nodules.
• Reassigning TIRADS category 4a nodules as TIRADS 3 will
improve the PPV and specificity of TIRADS.
• Overall agreement between observers for assigning TIRADS
category was substantial.
• Thus, TIRADS is a simple and practical method of assessing
thyroid nodules and can be used in practice.

95. THANK YOU

96. • Correlation of Thyroid Imaging Reporting and Data System [TI-RADS] and
fine needle aspiration: experience in 1,000 nodules;einstein.
2016;14(2):119-23,Rahal Junior A, Falsarella PM,Rocha RD, Lima JP, Iani
MJ, Vieira FA, Queiroz MR, Hidal JT, Francisco Neto MJ, Garcia RG, Funari
MB.

97. • The TI-RADS classification aims to correlate US features to
cytological classification, increasingly graduating the risk of a
nodule being malignant, according to the number of features
present in the US.
• Among diverse classifications, Horvath et al , by means of a
prospective analysis, proposed ten US patterns to be analyzed
during the examination and nodule classification from TI-RADS 2 to
6 (category 4 divided into 4A and 4B) and estimated a malignancy
risk of 14.1% in TI-RADS 3, 45% in TI-RADS 4, and 89.6% in TI-RADS
6.
• Kwak et al. proposed a TI-RADS classification through retrospective
analysis of patients submitted to thyroid US and FNA, considering
the risk of malignancy and subdivisions similar to the BI-RADS
classification (that is, with three subdivisions for category 4), using
five US criteria that can be added during thyroid evaluation.

98. • A significant association was found between the TI-RADS outcome and
Bethesda classification (p<0.001).
• Most individuals with TI-RADS 2 or 3 had Bethesda 2 result (95.5% and
92.5%, respectively).
• Among those classified as TI-RADS 4C and 5, most presented Bethesda 6
(68.2% and 91.3%, respectively; p<0.001).
• The proportion of malignancies among
• TI-RADS 2 was 0.8%, and TI-RADS 3 was 1.7%.
• TI-RADS 4A -----16.0%,
• 4B -------- 43.2% .
• 4C -------72.7%
• 91.3% among TI-RADS 5 (p<0.001),
• Showing clear association between TI-RADS and biopsy results.
Conclusion:
• The TI-RADS is appropriate to assess thyroid nodules and avoid
unnecessary fine needle aspiration, as well as to assist in making decision
about when this procedure should be performed.

99. • This article also described that a malignancy risk lower than
3% is expected for TI-RADS 3, a risk of 3.6 to 91.9% for TI-
RADS 4, and of 88.7 to 97.9% for TI-RADS 5.

100. • The present study has differences in relation to that proposed by Horvath
et al. such as being retrospective and with one more subdivision in the
category 4, by adding 4C.
• Besides our purpose was to facilitate the classification process, reducing
from ten to only four features in B-mode US considered in our
classification.
• It also differed from the study by Kwak et al. in this issue, since these
authors used five features in the classification, one more than ours.
• This difference relied on the nodule composition, that we judged as liable
to mistakes in some cases, since many mixed nodules could generate
uncertainty about their precise composition in ultrasonographic
evaluation.
• Instead, we considered two points of marked hypoechogenicity, because
the nodules with such characteristics have an increased risk of malignancy
as compared to those slightly hypoechoic.

101. The Bethesda System for Reporting Thyroid Cytopathology
Category Meaning
I Non-diagnostic or inadequate
II Benign
III Atypia/follicular lesion of undetermined significance
IV Follicular neoplasm or suspicious for follicular
neoplasm
V Suspicious for malignancy
VI Malignant
Source: Cibas et al.