TIRADS is an abbreviation which stands for Thyroid Imaging Reporting and Data System. It is a scoring system used by radiologists who perform ultrasound scans on the thyroid gland of patients who have suspected growths/nodules on them. Based on the appearance of the thyroid gland on the scan, different features are noted & given points for variations. This score can be used to assess the risk of chances of possible malignancy (cancer) in the thyroid and the need to perform further testing on the gland in the form of a Fine Needle Aspiration Cytology (FNAC) or a wedge biopsy.
A TIRADS calculator is a simple online tool that can be used to generate the TIRADS score. A trained radiologist can use the calculator efficiently.
Every nodule visualised by ultrasound can be characterised based on its appearance in an ultrasound scan into the following 5 categories.
Each of these categories is counted separately and has a points system as follows.
Cystic or almost completely cystic
Mixed cystic & solid
Solid or almost completely solid
Hyperechoic or Isoechoic
Wider than Tall
Taller than wide
Lobulated or irregular
None or large comet-tail artefacts
Peripheral (rim) calcifications
Punctate echogenic foci
The next step is to add the points from all the categories.
Based on the score, the status of the nodule is categorised as follows:
0 points - TR1
2 points - TR2
3 points - TR3
4-6 points - TR4
7 or more points - TR5
TR1 indicates that the nodule is Benign (non-cancerous) and does not require an FNAC. This corresponds to 0.3 % risk of malignancy.
TR2 indicates that the nodule is Not Suspicious, and does not require an FNAC. This corresponds to 1.5 % risk of malignancy.
TR3 indicates a Mildly Suspicious nodule. If the size of the nodule is more than 2.5cm, an FNAC is recommended. If it's between 1.5-2.5 cm then follow-up of the progression of the nodule is done periodically to watch for an increase in size. Follow-up intervals are at 1,3 & 5 years from the first visit. This corresponds to 4.8 % risk of malignancy.
TR4 indicates a Moderately Suspicious nodule. If the size is more than 1.5 cm, then FNAC is done. Follow-up is done if the size is between 1-1.5 cm. Follow up at 1, 2, 3, and 5 years. This corresponds to 9.1 % risk of malignancy.
TR5 means Highly Suspicious. Here an FNAC is done for any nodule over 1 cm in size. Those more than 1 cm are followed up closely. Yearly follow-up for 5 years is recommended. This corresponds to 35 % risk of malignancy.
The maximum score is 17. The higher the score, the higher the risk of malignancy, and the worse the prognosis.
If there are multiple nodules, all of these nodules are categorised and the two with the highest TIRADS scores are sampled by FNAC. These might not necessarily be the largest nodules.
Follow-up examination forms a key part of diagnosis and treatment. Some nodules with even a higher TIRADS score may not be feasible for an FNAC at present. These patients are closely followed up to look for significant enlargement. Significant enlargement is defined as a 50% increase in the volume or a more than 2mm/20% increase in two different dimensions of the nodule from previous findings.
Here are some of the limitations of the TIRADS Calculator.
Ultrasonography results are subjective and depend on the radiologists assessment of how the nodule looks when compared with the surrounding tissue and strap muscles of the neck. It also depends on the quality of the machine being used.
Pre-existing medical conditions like Hashimoto’s thyroiditis make it difficult to correctly interpret the ultrasonography findings. For example, a pattern with multiple hyper and hypoechoic patterns can be seen with Hashimoto’s and should not be a cause for concern.
Anechoic has a score of 0 while very hypoechoic has a score of 3. Both may be difficult to differentiate.
In case of
Rim calcifications obscure the nodule completely
Composition - “solid” and Echogenicity - “isoechoic”
Margin cannot be determined
Margin - “ill-defined”
Echogenicity cannot be determined
Echogenicity - “isoechoic”
Composition cannot be determined
Composition - “solid”
Always exercise caution while selecting any option with a higher score and make sure to cross-check your findings.
No, TIRADS calculator is just an indicator of benign or malignant status of a thyroid nodule. Further investigations are needed to confirm a diagnosis and plan the treatment.
TIRADS scoring requires training and the parameters can only be assessed by a trained radiologist.
Disclaimer: The content on this page is generic and shared only for informational and explanatory purposes. Please consult a doctor before making any health-related decisions.