For educational and reference use only. These calculators do not replace clinical judgement, local protocols, or a qualified clinician. Verify every result independently before it informs patient care.
Body imaging
C-RADS (CT Colonography, v2023)
CT Colonography Reporting and Data System, version 2023: colonic category from the largest / most significant finding. The 2023 update splits C2 into C2a and a new C2b for mass-like diverticular disease, which was previously being read as a mass. (Extracolonic categories are reported separately.)
Result
C-RADS C1
Continue routine screening, repeat in 5–10 years.
Formula
Colonic category from the largest finding: C0 inadequate · C1 no polyp ≥6 mm · C2a 6–9 mm, fewer than three · C2b mass-like diverticular disease · C3 ≥10 mm or ≥3 polyps 6–9 mm · C4 mass ≥30 mm or malignant-appearing.
References
Disclaimer
Report the extracolonic category separately. The 2023 update merged E1 and E2 into a single E1/E2, so the extracolonic set is E0, E1/E2, E3, E4. Management intervals also follow local screening policy.
For educational and reference use only. These calculators do not replace clinical judgement, local protocols, or a qualified clinician. Verify every result independently before it informs patient care.
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