🧫 CT Colonography C-RADS Classification
UseClassify a CT colonography study and set the management for both colonic and extracolonic findings.
SourceZalis ME, et al. CT Colonography Reporting and Data System (C-RADS) — 2023 update. Radiology 2023
This-shift next steps
After scoring: open the scene pack, peer scores, and the matching pathway. Local reference — no HIS write.
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Methodology · worked example, guidelines & full notes
Category set by the highest-grade lesion.
When to use
Classify a CT colonography study and set the management for both colonic and extracolonic findings.
How it works
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.
Key points
- 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.
References
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
Verification & sources · governance
FAQ
Frequently asked questions
- 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）