ACR TI-RADS Calculator for Thyroid Nodules

The ACR TI-RADS (Thyroid Imaging Reporting and Data System) is a 5-point scoring system for thyroid nodules, based on ultrasound findings, developed by the American College of Radiology. It facilitates diagnosis of thyroid nodule and discrimination between benign or malignant.

 

TI-RADS Explained

The ACR TI-RADS (Thyroid Imaging Reporting and Data System) is a 5-point scoring system for thyroid nodules, based on ultrasound findings, developed by the American College of Radiology and published in 2017.

It facilitates diagnosis of thyroid nodule and discrimination between benign or malignant so benefits identifying clinically important cancers whilst balancing the risk and cost of subjecting patients with benign nodules to biopsy and treatment.

TI-RADSAnswer ChoicesExplanatory NotesCompositionCystic or almost completely cystic (0)
Spongiform (0)
Mixed cystic and solid (1)
Solid or almost completely solid (2)
Indeterminate due to calcification (2)Spongiform: Composed predominantly (>50%) of small cystic spaces. No further points are added for other categories.
Mixed cystic and solid: Assign points for predominant solid component.EchogenicityAnechoic (0)
Hyperechoic or isoechoic (1)
Hypoechoic (2)
Very hypoechoic (3)
Cannot be determined (1)Anechoic: Applies to cystic or almost completely cystic nodules.
Hyperechoic/isoechoic/hypoechoic: Compared to adjacent parenchyma.
Very hypoechoic: More hypoechoic than strap muscles.ShapeWider than tall (0)
Taller than wide (3)Shape should be assessed on a transverse image with measurements parallel to sound beam for height and perpendicular to sound beam for width.MarginSmooth (0)
Ill-defined (0)
Lobulated or irregular (2)
Extra-thyroidal extension (3)
Cannot be determined (0)Lobulated: Protrusions into adjacent parenchyma.
Irregular: Jagged, spiculated, or sharp angles.
Extrathyroidal extension: Obvious invasion of adjacent soft tissue or vascular structures.Echogenic foci(Choose all that apply)
None or large comet-tail artifacts (0)
Macrocalcifications (1)
Peripheral (rim) calcifications (2)
Punctate echogenic foci (3)Large comet-tail artifacts: V-shaped, >1 mm, in cystic components.
Macrocalcifications: Cause acoustic shadowing.
Peripheral calcifications: Complete or incomplete along margin.
Punctate echogenic foci: Non-shadowing, may have small comet-tail artifacts.

The number of thyroid nodules detected via ultrasound is increasing and whilst most are benign, it is essential to evaluate which may require further investigation via fine needle aspiration (FNA) cytology/ biopsy.

Nodules should be measured in three orthogonal planes and in case there are multiple nodules, not more than 4 nodules should be documented.

Growth may be defined as:

• More than 20% increase in at lease two dimensions AND minimal increase of 2mm;
• OR More than 50% increase in volume.

The ultrasound features in the ACR TI-RADS are categorized as benign, minimally suspicious, moderately suspicious, or highly suspicious for malignancy. Points are given for all the ultrasound features in a nodule, with more suspicious features being awarded additional points.