Lung cancer screening — CT (Lung-RADS)

CTACR Lung-RADS v2022

Low-dose CT lung cancer screening in an eligible high-risk patient.

Applies to

Low-dose CT lung cancer screening in an eligible patient (age and smoking-history criteria met)

Does not apply to

Incidental nodule outside a screening program (use Fleischner)
Diagnostic CT for symptoms or known cancer

What to report

Tap an item to check it off while dictating.

1.Size
Mean of long- and short-axis to one decimal (mm). For part-solid nodules, measure the solid component separately — it drives the category.
2.Attenuation
Solid, part-solid, or nonsolid (ground-glass).
3.Baseline / new / growing
State whether the nodule is at baseline, new since a prior negative screen, or growing — thresholds differ.
4.Growth
Growth is an increase of > 1.5 mm in mean diameter. Note slow growth over multiple exams (classified as 4B).
5.Suspicious features (4X)
Spiculation, GGN doubling within one year, or an enlarged/abnormal node upgrades a category 3 or 4 nodule to 4X.
6.Other findings (S modifier)
Report clinically significant incidental findings (e.g. coronary calcification, emphysema) with the S modifier.

Scores & calculators

Lung-RADS

ACR Lung-RADS v2022

Category and management for a screen-detected pulmonary nodule on low-dose CT lung cancer screening.

Finding

No nodule (negative screen)Solid nodulePart-solid noduleGround-glass (nonsolid) nodule

Timing

Baseline (first) screenNew (from a prior negative screen)

Mean diameter (total)

Solid component (part-solid only)

Additional suspicious features (→ 4X)

NonePresent (e.g. spiculation, GGN doubling <1 y, enlarged node)

Complete the inputs to see the result.

Ellipsoid volume

Volume of an ellipsoid lesion or organ from three orthogonal diameters.

Length

Width

Height

Complete the inputs to see the result.

Ellipsoid formula V = (π/6) × L × W × H. 1 cm³ = 1 mL.

Percentage volume / size change

Percentage change between a prior and current measurement.

Prior value

Current value

Complete the inputs to see the result.

Percentage change = (current − prior) / prior × 100. Use consistent units (diameter or volume).

Sources

ACR Lung-RADS v2022 — American College of Radiology (2022)

Content review: Content pending clinical review · 2026-07-10

Educational reference for trained clinicians. Verify every result against the cited original guideline before use. Not a substitute for clinical judgment or medical advice.