Unifying Concepts

CT Colonography Reporting and Data System (C-RADS)

In 2005, the CT Colonography Reporting and Data System (C-RADS) was established to provide a means of classifying findings of CT colonography (CTC) and of applying the advantages of structured reporting to the setting of colorectal cancer screening.

CT Colonography Reporting and Data System (C-RADS)




C0, inadequate study

Inadequate preparation; inadequate insufflation

C1, normal colon or benign lesion

No polyp >/= 6 mm; recommend routine screening with CT colonography or colonoscopy in 5 years

C2, intermediate polyp or indeterminate finding

Polyps 6–9 mm, < 3 in number; recommend CT colonography polyp surveillance or colonoscopy with polypectomy

C3, polyp, possibly advanced adenoma

Polyps >/= 10 mm; >/= 3 polyps, each 6–9 mm; recommend colonoscopy with polypectomy

C4, colorectal mass, likely malignant

Lesion compromises bowel lumen, shows extracolonic invasion; recommend surgical consultation


E0, limited examination

Compromised by artifact; evaluation of extracolonic tissues severely limited

E1, normal examination or anatomic variant

No extracolonic abnormalities visible; no workup indicated

E2, clinically unimportant finding

Examples: simple liver or kidney cyst, cholelithiasis without cholecystitis; no workup indicated

E3, likely unimportant, incompletely characterized

Example: minimally complex or homogeneously hyperattenuating kidney cyst; workup may be indicated; dependent on specific clinical scenario

E4, potentially important finding

Examples: solid kidney mass, aortic aneurysm; workup generally indicated, but dependent on specific clinical scenario; communicate to referring physician as per accepted practice guidelines



  1. Yee J, Chang KJ, Dachman AH, Kim DH, McFarland EG, Pickhardt PJ, Cash BD, Bruining DH, Zalis ME. The Added Value of the CT Colonography Reporting and Data System. J Am Coll Radiol. 2016 Aug;13(8):931-5. [Medline]
  2. Pooler BD, Kim DH, Lam VP, Burnside ES, Pickhardt PJ. CT Colonography Reporting and Data System (C-RADS): benchmark values from a clinical screening program. AJR Am J Roentgenol. 2014 Jun;202(6):1232-7. [Medline]
  3. Zalis ME, Barish MA, Choi JR, Dachman AH, Fenlon HM, Ferrucci JT, Glick SN, Laghi A, Macari M, McFarland EG, Morrin MM, Pickhardt PJ, Soto J, Yee J; Working Group on Virtual Colonoscopy. CT colonography reporting and data system: a consensus proposal. Radiology. 2005 Jul;236(1):3-9. [Medline]


Created Jan 24, 2018.

  • Language:

  • Users Online

  • Medical Disclaimer

    El contenido de este sitio web son solo para fines informativos y no reemplazan la consulta con un profesional médico.
  • Recent Posts

  • Categories

  • Copyright by