TIRADS Classification

The TIRADS (Thyroid Imaging Reporting and Data System) classification is a standardized system used to evaluate and categorize thyroid nodules based on their ultrasound characteristics. The goal of the TIRADS classification is to stratify the risk of malignancy in thyroid nodules, helping clinicians decide which nodules may need further investigation, such as a fine-needle aspiration biopsy.

For more details about tirads, check this study and this study.

TIRADS Classification Categories:

1. TIRADS 1: Benign

Tirads 1 has the following details:

• Risk of Malignancy: 0%
• Ultrasound Features: No suspicious features; the nodule is entirely benign.
• Examples: Simple cysts or spongiform nodules.

2. TIRADS 2: Not Suspicious (Benign)

Here are the details for Tirads 2:

• Risk of Malignancy: 0-2%
• Ultrasound Features: Purely cystic or spongiform nodules with no suspicious characteristics.
• Management: Typically no further action needed; follow-up only if there are changes.

3. TIRADS 3: Mildly Suspicious

Find the details below for tirads 3:

• Risk of Malignancy: 2-5%
• Ultrasound Features: Nodule is solid and iso- or hyperechoic with no high-risk features.
• Management: Consider follow-up ultrasound to monitor changes, particularly if the nodule is >2.5 cm.

4. TIRADS 4: Moderately Suspicious

Find the details below for tirads 4:

• Risk of Malignancy: 5-15%
• Ultrasound Features: Nodule is mildly hypoechoic with one or more suspicious features (e.g., irregular margins, microcalcifications, taller-than-wide shape).
• Management: Consider fine-needle aspiration biopsy for nodules ≥1.5 cm or follow-up for smaller nodules.

5. TIRADS 5: Highly Suspicious

Find the details about Tirads 5 below:

• Risk of Malignancy: >20%
• Ultrasound Features: Nodule is very hypoechoic with multiple high-risk features (e.g., irregular margins, microcalcifications, extrathyroidal extension).
• Management: Fine-needle aspiration biopsy recommended for nodules ≥1 cm; smaller nodules may require close monitoring or biopsy depending on clinical judgment.

Related: Calculate tirads using our tirads calculator.

Key Features Considered in TIRADS Classification:

• Composition: Cystic, spongiform, solid, or mixed.
• Echogenicity: Hyperechoic, isoechoic, hypoechoic, or very hypoechoic.
• Shape: Taller-than-wide (anterior-posterior diameter greater than transverse diameter).
• Margin: Smooth, irregular, lobulated, or extrathyroidal extension.
• Echogenic foci: Presence of microcalcifications, macrocalcifications, or peripheral calcifications.

Purpose of TIRADS:

The TIRADS classification system aims to:

• Standardize the assessment and reporting of thyroid nodules.
• Reduce unnecessary biopsies by focusing on nodules with higher risk features.
• Improve the detection of potentially malignant nodules through a systematic approach.

Clinical Use:

• Biopsy Indication: Nodules categorized as TIRADS 4 or 5 typically warrant further investigation, such as a biopsy, to rule out malignancy.
• Follow-Up: Nodules in lower TIRADS categories (1-3) may be monitored with periodic ultrasounds, depending on their size and any changes over time.

The TIRADS classification is a valuable tool for radiologists and endocrinologists to make informed decisions about the management of thyroid nodules, ensuring appropriate care for patients.

Reference

1. Mendes GF, Garcia MR, Falsarella PM, Rahal A, Cavalcante Junior FA, Nery DR, Garcia RG. Fine needle aspiration biopsy of thyroid nodule smaller than 1.0 cm: accuracy of TIRADS classification system in more than 1000 nodules. Br J Radiol. 2018 Feb;91(1083):20170642. doi: 10.1259/bjr.20170642. Epub 2017 Dec 22. PMID: 29182368; PMCID: PMC5965458.
2. Dy JG, Kasala R, Yao C, Ongoco R, Mojica DJ. Thyroid Imaging Reporting and Data System (TIRADS) in Stratifying Risk of Thyroid Malignancy at The Medical City. J ASEAN Fed Endocr Soc. 2017;32(2):108-116. doi: 10.15605/jafes.032.02.03. Epub 2017 Aug 2. PMID: 33442093; PMCID: PMC7784109.