CT Colonography C-RADS Classification — free guideline decision tool
Get the colonic (C0–C4) and extracolonic (E0–E4) categories and management for CT colonography per C-RADS v2023. Instant, browser-side.
Open guideline tool →Guideline-based
Implements the decision logic from published clinical guidelines.
Runs in your browser
No installation. Enter the patient's values and get a guideline recommendation instantly.
Data stays local
Nothing is uploaded. Results are for licensed clinicians only.
Worked calculation
The values below come from this tool's own example placeholders and are computed server-side with the formula shown on this page, so the arithmetic can be checked quickly. It demonstrates how to substitute values only — it is not clinical advice and not a real case.
| Colonic category (C) | C2 — 1–2 polyps 6–9 mm (incl. C2b diverticular stricture) |
|---|---|
| Extracolonic category (E, optional) | E1/E2 — Normal or clinically unimportant |
→Colonic managementCTC surveillance / colonoscopy
- Colon C2：1–2 polyps 6–9 mm (intermediate); incl. C2b diverticular mass-like stricture (probably benign); management: CTC surveillance (~3 years) or colonoscopy/polypectomy (per patient preference and risk)
- Extracolonic E1/E2：Normal or clinically unimportant / stable known (e.g. simple renal/hepatic cyst, gallstones); management: No further work-up
- Note：C-RADS v2023: colonic C0–C4 (adds C2b diverticular mass-like stricture), extracolonic E0–E4 (E1/E2 merged,[pending update] reporting optional); category set by the highest-grade lesion
| Colonic category (C) | C0 — Inadequate / non-diagnostic |
|---|---|
| Extracolonic category (E, optional) | Not assessed / not selected |
→Colonic managementRepeat / supplement
- Colon C0：Inadequate / non-diagnostic (poor prep or distension, or awaiting prior comparison); management: Repeat or supplement, then re-classify
- Note：C-RADS v2023: colonic C0–C4 (adds C2b diverticular mass-like stricture), extracolonic E0–E4 (E1/E2 merged,[pending update] reporting optional); category set by the highest-grade lesion
- Basis：C-RADS CT Colonography Reporting and Data System v2023
Common questions
What is CT Colonography C-RADS Classification?
Get the colonic (C0–C4) and extracolonic (E0–E4) categories and management for CT colonography per C-RADS v2023. Instant, browser-side.
How is CT Colonography C-RADS Classification calculated? What is the core formula?
C1 normal → routine screening (5–10 yr); C2 (1–2 polyps 6–9 mm) → CTC surveillance ~3 yr or colonoscopy; C3 (≥ 10 mm or ≥ 3 polyps 6–9 mm) → colonoscopy; C4 suspected malignant → surgical/oncology referral.
When is CT Colonography C-RADS Classification used?
Classify a CT colonography study and set the management for both colonic and extracolonic findings.
What are the key clinical points for CT Colonography C-RADS Classification?
Category set by the highest-grade lesion. v2023 adds C2b (diverticular mass-like stricture) and merges E1/E2. Extracolonic E1/E2 need no follow-up; E3 work-up as indicated; E4 further management. [pending update]extracolonic reporting is optional in v2023.
What are the limits and cautions when using CT Colonography C-RADS Classification?
For licensed clinicians and clinical researchers. Interpret results with history, investigations and local protocols; not a diagnosis or prescription, and not a substitute for multidisciplinary decision-making or local guidelines.
Does CT Colonography C-RADS Classification upload patient data? Where is it calculated?
Calculation runs locally in the browser; inputs and results are not uploaded. For licensed clinicians only; interpret with history, investigations and local protocols — not a diagnosis or prescription.
How is CT Colonography C-RADS Classification calculated in practice? Can you show a worked example?
Inputs: Colonic category (C) C2 — 1–2 polyps 6–9 mm (incl. C2b diverticular stricture), Extracolonic category (E, optional) E1/E2 — Normal or clinically unimportant → Result: Colonic management CTC surveillance / colonoscopy（Colon C2: 1–2 polyps 6–9 mm (intermediate); incl. C2b diverticular mass-like stricture (probably benign); management: CTC surveillance (~3 years) or colonoscopy/polypectomy (per patient preference and risk), Extracolonic E1/E2: Normal or clinically unimportant / stable known (e.g. simple renal/hepatic cyst, gallstones); management: No further work-up, Note: C-RADS v2023: colonic C0–C4 (adds C2b diverticular mass-like stricture), extracolonic E0–E4 (E1/E2 merged,[pending update] reporting optional); category set by the highest-grade lesion） Inputs: Colonic category (C) C0 — Inadequate / non-diagnostic, Extracolonic category (E, optional) Not assessed / not selected → Result: Colonic management Repeat / supplement（Colon C0: Inadequate / non-diagnostic (poor prep or distension, or awaiting prior comparison); management: Repeat or supplement, then re-classify, Note: C-RADS v2023: colonic C0–C4 (adds C2b diverticular mass-like stricture), extracolonic E0–E4 (E1/E2 merged,[pending update] reporting optional); category set by the highest-grade lesion, Basis: C-RADS CT Colonography Reporting and Data System v2023）
Run CT Colonography C-RADS Classification now
Get the colonic (C0–C4) and extracolonic (E0–E4) categories and management for CT colonography per C-RADS v2023. Instant, browser-side.
Open guideline tool →For licensed clinicians. Not a substitute for clinical judgement.
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