Thyroid imaging reporting and data system (TI-RADS)

Changed by Daniel J Bell, 28 May 2019

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TI-RADS is a risk stratification system for classifying thyroid lesions, originating from a study from 2009 ³, and ~~was recently recognized~~described in an American College of Radiology (ACR) white paper in 2015 ¹. Its use ~~is being~~was originally advocated in a similar vein to the use of BI-RADS ~~category for~~ for breast lesions.

In 2017, a new white paper² was released by the ACR committee on thyroid imaging with a standardised scoring system, with guidance on fine needle aspiration (FNA) and follow-up.

This ~~system has been superseded by~~resulted in the revised ACR TI-RADS system which superseded the original TI-RADS described herein.

Classification

~~Classification~~Originally this classification system ~~has been~~was proposed by Horvath et al. ³ in 2009, with a modified recommendation from Jin Kwak et al. in 2011 ⁴.

Similar to BI-RADS category, the sonographic TI-RADS classification iswas as follows:

TI-RADS 1: normal thyroid gland
TI-RADS 2: benign lesions
TI-RADS 3: probably benign lesions
TI-RADS 4: suspicious lesions (subclassified as 4a, 4b, and later 4c ⁴ with increasing risk of malignancy)
TI-RADS 5: probably malignant lesions (more than 80% risk of malignancy)
TI-RADS 6: biopsy proven malignancy

TI-RADS 2 category

avascular anechoic lesion with echogenic specks (colloid type I)
vascular heteroechoic non-expansile, non-encapsulated nodules with peripheral halo (colloid type II)
isoechoic or heteroechoic, non-encapsulated, expansile vascular nodules (colloid type III)

These conditions have 0% risk of malignancy.

TI-RADS 3 category

hyperechoic, ~~iso-echoic~~isoechoic or hypoechoic nodules, with partially formed capsule and peripheral vascularity, usually in setting of Hashimoto thyroiditis (Hashimoto pseudonodule)

Modified TIRADS classification ⁴ have simplified TIRADS 3 category as none of the suspicious malignant sonographic features described below. These lesions are mostly benign with <5% risk of malignancy ³.

TI-RADS 4 and 5 categories

These categories are based on five suspicious sonographic features of malignancy:

solid component
- high stiffness of nodule on elastography if available
markedly hypoechoic nodule
microlobulations or irregular margins
microcalcifications
taller-than-wider shape

Subclassificaton

TI-RADS 4a: one suspicious feature
TI-RADS 4b: two suspicious features
TI-RADS 4c: three/four suspicious features
TI-RADS 5: all five suspicious features

TI-RADS 4a has 5-10% risk of malignancy, 4b and 4c may have 10-80% risk of malignancy. TI-RADS 5 category lesion have >80% risk of malignancy ³.

Please note: At the time of writing this article (mid 2016), this classification system in any version has not been formally accepted by ACR or any global radiological convention. Yet this classification system is well reported. Article is based on proposed classification systems, which should be known to the radiologists, and may help them in characterizing thyroid lesions. It may be used for risk stratification on sole discretion of personnel or institution, and should be complemented by FNAC on need basis.

-TI-RADS is a risk stratification system for classifying thyroid lesions and was recently recognized in an American College of Radiology (ACR) white paper1. Its use is being advocated similar to <a href="/articles/breast-imaging-reporting-and-data-system-bi-rads">BI-RADS</a> category for breast lesions. In 2017, a white paper2 was released by the ACR committee on thyroid imaging with a standardised scoring system, with guidance on <a href="/articles/ultrasound-guided-fna-of-the-thyroid">fine needle aspiration</a> (FNA) and follow-up.This system has been superseded by the <a href="/articles/acr-thyroid-imaging-reporting-and-data-system-acr-ti-rads">ACR TI-RADS</a> system.<h4>Classification</h4>Classification system has been proposed by Horvath et al. 3, with a modified recommendation from Jin Kwak et al. 4.Similar to BI-RADS category, sonographic TI-RADS classification is as follows:<ul>
+TI-RADS is a risk stratification system for classifying thyroid lesions, originating from a study from 2009 3, and described in an <a title="American College of Radiology (ACR)" href="/articles/american-college-of-radiology">American College of Radiology (ACR)</a> white paper in 2015 1. Its use was originally advocated in a similar vein to the use of <a href="/articles/breast-imaging-reporting-and-data-system-bi-rads">BI-RADS</a> for breast lesions. In 2017, a new white paper 2 was released by the ACR committee on thyroid imaging with a standardised scoring system, with guidance on <a title="Fine needle aspiration (FNA)" href="/articles/fine-needle-aspiration-fna">fine needle aspiration (FNA)</a> and follow-up. This resulted in the revised <a href="/articles/acr-thyroid-imaging-reporting-and-data-system-acr-ti-rads">ACR TI-RADS</a> system which superseded the original TI-RADS described herein.<h4>Classification</h4>Originally this classification system was proposed by Horvath et al. 3 in 2009, with a modified recommendation from Jin Kwak et al. in 2011 4.Similar to BI-RADS category, the sonographic TI-RADS classification was as follows:<ul>
-</ul>These conditions have 0% risk of malignancy.<h5>TI-RADS 3 category</h5><ul><li>hyperechoic, iso-echoic or hypoechoic nodules, with partially formed capsule and peripheral vascularity, usually in setting of <a href="/articles/hashimoto-thyroiditis">Hashimoto thyroiditis</a> (Hashimoto pseudonodule)</li></ul>Modified TIRADS classification 4 have simplified TIRADS 3 category as none of the suspicious malignant sonographic features described below. These lesions are mostly benign with <5% risk of malignancy 3.<h5>TI-RADS 4 and 5 categories</h5>These categories are based on five suspicious sonographic features of malignancy:<ul>
+</ul>These conditions have 0% risk of malignancy.<h5>TI-RADS 3 category</h5><ul><li>hyperechoic, isoechoic or hypoechoic nodules, with partially formed capsule and peripheral vascularity, usually in setting of <a href="/articles/hashimoto-thyroiditis">Hashimoto thyroiditis</a> (Hashimoto pseudonodule)</li></ul>Modified TIRADS classification 4 have simplified TIRADS 3 category as none of the suspicious malignant sonographic features described below. These lesions are mostly benign with <5% risk of malignancy 3.<h5>TI-RADS 4 and 5 categories</h5>These categories are based on five suspicious sonographic features of malignancy:<ul>
~~-<a href="/articles/breast-imaging-reporting-and-data-system-bi-rads">BIRADS</a> classification system</li>~~
-</ul>Please note: At the time of writing this article (mid 2016), this classification system in any version has not been formally accepted by ACR or any global radiological convention. Yet this classification system is well reported. Article is based on proposed classification systems, which should be known to the radiologists, and may help them in characterizing thyroid lesions. It may be used for risk stratification on sole discretion of personnel or institution, and should be complemented by FNAC on need basis.
+<a href="/articles/breast-imaging-reporting-and-data-system-bi-rads">BI-RADS</a> classification system</li>
+</ul>