TIRADS ACR : What radiologists need to know!

TIRADS Introduction:

• With the advent of high-resolution ultrasound, the number of thyroid nodules being detected is increasing. Most of these nodules are benign. Even the smaller malignant nodules have an indolent course [1]. Also, the mortality associated with papillary thyroid carcinomas has remained low[1]. Hence it is essential to evaluate which of these nodules actually need a fine needle aspiration cytology (FNAC)/biopsy, which is the most effective method currently to diagnose whether a particular nodule is worrisome. Unnecessary biopsies can result in a burden on the healthcare system without significant benefits [1].

What is TIRADS / ti rads / TI-RADS and what does it stand for?

TI-RADS stands for Thyroid Imaging Reporting and Data System. It is a reporting system for thyroid nodules on Ultrasound formulated by the ACR, akin to BI-RADS developed for breast ultrasounds. It consists of guidelines regarding whether a thyroid nodule should be followed up on ultrasound or to should be biopsied.

What is ACR TIRADS? 

• Different variations of the TI-RADS classifications and recommendations are available, the most commonly followed one is the ACR TI-RADS. A recent study published in AJR confirms that the ACR TI-RADS performs well as compared to other scoring systems [2].
• ACR  Committee for TI-RADS has the following objectives [3]:
  • 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 a biopsy.

TIRADS Guidelines:

• The guidelines have been described as per the ACR TI-RADS 2017 radiology white paper.  The full text of this article is available here: ACR TI-RADS white paper 2017 pdf.
• These guidelines provide criteria and recommendations for follow-up and biopsy of thyroid nodules.
• Similar to the BI-RADS classification, thyroid nodules on ultrasound are classified  according to the risk of malignancies into the following categories [1]:

Download a ready to print image of the TIRADS classification

• • One need not memorize this table, instead, you can print a copy of this TI RADS chart and put it up near your reporting station. Click here for a ready to print image of the table. Alternatively, you can use this image provided by the ACR online [1]: ACR TI-RADS
  • Thyroid nodules are evaluated on certain sonographic criteria, each criterion is allotted points which are summed up and then each nodule is categorized in one of the above-mentioned categories, depending on the score.

• Following criteria have been described:

*Spongiform nodule should be composed predominantly (>50%) of cystic spaces.

# “Large comet-tail artifacts” are defined as echogenic foci with V-shaped echoes >1 mm deep to them.

$ Punctate echogenic foci are non-shadowing.  

TIRADS ACR categories TIRADS ACR classification

Download a ready to print image of the TIRADS categories

Note: 

• Doppler has not found to be useful in distinguishing benign from malignant lesions, however, the presence of vascularity rules out debris and hemorrhage which are inconsequential [1].
• The presence of “halo” is not specific and is not included in the lexicon.
• Additional benign appearances are not included in the lexicon, for eg
  • White knight: Uniformly hyperechoic nodule.
  • Giraffe hide:  Mixed hyper and hypoechoic areas.
• There is no mention of the role of thyroid elastography in the guidelines.

TIRADS Reporting guidelines for thyroid nodules:

• Nodules should be measured in three orthogonal planes.
• If there are multiple nodules, not more than 4 nodules should be documented.
• Definition of growth:
  • More than 20% increase in at least two dimensions AND a minimal increase of 2mm OR
  • More than 50% increase in volume.
  • It is important to compare not just with the immediate previous studies, but with the previous ones as well.
• Number of nodules to biopsy: If multiple nodules are present, biopsy two nodules with the highest score, which may not necessarily be the largest nodules. Suspicious nodes if present should also be biopsied.
• Cervical nodes: Following suspicious features have been described [1]:
  • • Globular shape
    • Loss of normal echogenic hilum
    • Presence of peripheral rather than hilar flow
    • Heterogeneity with cystic components
    • Punctate echogenic foci that may represent microcalcifications.

A simplified approach to thyroid ultrasound and TI-RADS:

The interpretation guidelines in the ACR white paper may seem complex to radiologists and sonologists. ACR has excellent resources to simplify the reporting of thyroid nodules. These include the TIRADS atlas, reporting templates and educational webinars on the topic. Here are the links:

• TIRADS atlas: ACR TI-RADS Atlas with images for reference for each category.
• TI RADS Sonographer’s Worksheet

ACR TIRADS chart:

Keep a copy of this flowchart in your ultrasound room for ready reference.

 

 

ACR TIRADS webinars:

ACR has made these excellent webinars publicly available on YouTube for reference. 

Part I – ACR TI-RADS Webinar Part I: This Is How We Do It

Part II – ACR TIRADS Webinar Part II: Case-Based Review & Frequently Asked Questions

Part III – ACR TI-RADS Webinar Part III: Why Adopt ACR TI-RADS? Evidence Behind Performance

Part IV :TI-RADS Diagnostic Ultrasound Reporting Template

NECK USG by Dr. Alka Singhal: Introduction to TI-RADS

NECK USG by Dr. Alka Singhal: Introduction to TI-RADS

Thyroid Ultrasound Reporting Template using ACR TIRADS:

Patient Identification: 

Patient Demographics: 

Indication:

Technique: Ultrasound examination of the thyroid and adjacent soft tissues was performed.

FINDINGS

Thyroid size:

Texture:

Estimated total number of nodules ≥1cm: 1, 2, 3, 4, 5, 6-10, >10]

Number of spongiform nodules ≥2cm not described below (TR1): [ ]

Number of mixed cystic and solid nodules ≥1.5cm not described below (TR2): [ ]

Nodule #: [1, 2, 3, 4]

Maximum size: [ ] cm; Other 2 dimensions [ ] cm Location: [right, left, isthmus];[upper, mid, lower]

Composition: [cystic/almost completely cystic (0), spongiform (0), mixed cystic and solid (1), solid/almost completely solid (2), cannot determine (2)]

Echogenicity: [anechoic (0), hyperechoic (1), isoechoic (1), hypoechoic (2), very hypoechoic (3), cannot determine (1)]

Shape: [not taller-than-wide (0), taller-than-wide (3)]

Margins: [smooth (0), ill-defined (0), lobulated/irregular (2), extra-thyroidal extension (3), cannot determine (0)]

Echogenic foci: [none (0), large comet-tail artifacts (0), macrocalcifications (1), peripheral calcifications (2), punctate echogenic foci (3)]

Additional echogenic foci 1:

Significant change in size (>/= 20% in two dimensions and minimal increase of 2 mm): [No/Yes]

Change in features: [No/Yes]

Change in ACR TI-RADS risk category: [No/Yes]

ACR TI-RADS total points: [ ] ACR TI-RADS risk category: [TR1 (0 points), TR2 (2 points), TR3 (3 points), TR4 (4-6 points), TR5 (≥7 points)]

ACR TI-RADS recommendation: [Ultrasound-guided fine needle aspiration, Follow-up ultrasound in 1 year, No further follow-up]

IMPRESSION:

 ACR TI-RADS recommendations

TR5 (≥7 points) – FNA if ≥ 1cm, follow-up if 0.5 – 0.9 cm every year for 5 years

TR4 (4-6 points) – FNA if ≥ 1.5cm, follow-up if 1 – 1.4 cm in 1, 2, 3 and 5 years

TR3 (3 points)- FNA if ≥ 2.5cm, follow-up if 1.5 – 2.4 cm in 1, 3 and 5 years

TR2 (2 points) & TR1 (0 points) – No FNA or follow-up

 

Alternatively, you can download the template from here: TI-RADS Diagnostic Ultrasound Reporting Template

ACR has also provided this template for reporting of Thyroid biopsies:  Thyroid Ultrasound Biopsy Structured Reporting Template using ACR TI-RADS

TIRADS examples with scoring: Test yourself!

Go through the categories once again, use the TIRADS calculator and test yourself!

Example 1 :

What is the TIRADS score for this nodule?

Example 2

What is the TIRADS score for this nodule?

Example 3:

What is the TIRADS score for this nodule?

Example 4:

What is the TIRADS score for this nodule?

If you got these wrong revise the guidelines here again.

Other useful TIRADS resources:

• TI-RADS Biopsy Reporting Template  
• ACR TI-RADS Atlas with images for reference for each category.
• TI-RADS Sonographer’s Worksheet
• TI-RADS guide for a description of features: TIRADS examples
• Thyroid Imaging Reporting and Data System (TI-RADS): A User’s Guide: A radiology article for reference.

 

References:

1. Rumack Diagnostic Ultrasound
2. Tessler FN, Middleton WD, Grant EG, et al. ACR Thyroid Imaging, Reporting and Data System (TI-RADS): white paper of the ACR TI-RADS Committee. J Am Coll Radiol 2017; 14:587–595.
3. Middleton WD, Teefey SA, Reading CC, Langer JE, Beland MD, Szabunio MM, et al. Comparison of Performance Characteristics of American College of Radiology TI-RADS, Korean Society of Thyroid Radiology TIRADS, and American Thyroid Association Guidelines. AJR Am J Roentgenol. 2018;210(5):1148-54.
4. TI-RADS. (2018). Acr.org. Retrieved 20 August 2018, from https://www.acr.org/Clinical-Resources/Reporting-and-Data-Systems/TI-RADS

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