TIRADS : 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. It consists of guidelines regarding whether a thyroid nodule should be followed up on ultrasound or to should be biopsied.

What is TIRADS? 

• Different variations of the TI-RADS classifications and recommendations are available, the most commonly followed one is the TI-RADS. A recent study published in AJR confirms that the TI-RADS performs well as compared to other scoring systems [2].
• 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 TI-RADS 2017 radiology white paper.  The full text of this article is available here: 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 online [1] 
  • 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.  

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 White paper may seem complex to radiologists and sonologists.

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

Thyroid Ultrasound Reporting Template using 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 TI-RADS risk category: [No/Yes]

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

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

IMPRESSION:

 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

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  
• 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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