O-RADS US

Radiopaedia • CC-by-nc-sa 3.0 • de

The Ovarian-Adnexal Reporting and Data System Ultrasound (O-RADS US) forms the ultrasound component of the Ovarian-Adnexal Reporting and Data System (O-RADS). This system aims to ensure that there are uniform unambiguous sonographic and MRI evaluations of ovarian or other adnexal lesions, accurately assigning each lesion to a risk category of malignancy being present, which informs the appropriate management to be instituted.

For MRI, see the Ovarian-Adnexal Reporting and Data System MRI (O-RADS MRI).

These are the components of the ultrasound evaluation:

  • lexicon 
  • risk-stratification score 

These recommendations have been published to guide the management of "average-risk patients without acute symptoms" who demonstrate adnexal lesions. Individual case management may be modified based on professional judgment, regardless of the O-RADS ultrasound recommendations.

Classification

For risk stratification, the O-RADS US system uses six categories (O-RADS 0–5), from normal (0) to high risk of malignancy (5).

O-RADS US 0
  • an incomplete evaluation
O-RADS US 1

Physiologic category (normal premenopausal ovary)

  • ovarian follicle (<3 cm)
  • corpus luteum (<3 cm)
O-RADS US 2

Almost certainly benign category (<1% risk of malignancy)

  • simple cyst 3-5 cm
    • premenopausal: no follow-up
    • postmenopausal: 1-year follow-up
  • simple cyst 5-10 cm
    • premenopausal: 8-12 week follow-up
    • postmenopausal: 1-year follow-up
  • non-simple but unilocular cyst with smooth margins <3 cm
    • premenopausal: no follow-up
    • postmenopausal: 1-year follow up if referring to ultrasound specialist or MRI management by a gynecologist
  • non-simple but unilocular cyst with smooth margins 3-10 cm
    • premenopausal: 8-12 week follow-up
    • postmenopausal: refer to ultrasound specialist or MRI; management by a gynecologist
  • lesions with "classical ultrasound characteristics" of the following but may have specific recommendations:
O-RADS US 3

Low risk of malignancy (1% to <10%) - needs a referral to ultrasound specialist or gynecologist with a view to MRI

  • unilocular >10 cm (simple or non-simple)
  • lesions looking like typical dermoids, endometriomas or hemorrhagic cysts >10 cm
  • solid smooth lesion of any with color score 1 
  • multilocular cyst <10 cm smooth inner wall with color score 1-3
O-RADS US 4

Lesions with an intermediate risk of malignancy (10% to <50%) - needs ultrasound specialist review or MRI as well as management by a gynecologist with gynecological oncology support or solely by a gynecological oncologist

  • unilocular cyst with a solid component, any size, 1-3 papillary projections, any color score
  • multilocular cyst with solid component, any size, color score 1-3
  • multilocular cyst without solid component
    • >10 cm, smooth inner wall with color score 1-3
    • any size smooth inner wall with color score of 4
    • any size with an irregular inner wall or irregular septations of any color score
  • solid smooth lesion of any with color score 2-3
​O-RADS US 5

Lesions with a high risk of malignancy (≥50%) - needs a referral to gynecological oncologist

  • presence of ascites / peritoneal nodularity
  • unilocular cyst with papillary projections
  • multilocular cyst with a solid component
  • solid lesion - some criteria apply - color score 4
  • solid irregular lesion of any size
Color scoring (CS) indicator
  • CS1: no flow
  • CS2: minimal flow
  • CS3: moderate flow
  • CS4: strong flow

History and etymology

O-RADS was developed and published in 2018 by an international multidisciplinary committee, comprising clinicians and researchers from the fields of radiology, gynecology, pathology, and gynecologic oncology, and sponsored by the American College of Radiology (ACR). It was originally designed for sonographic evaluation, and in 2020 the system was extended to include MRI evaluation. The O-RADS MRI was an evolution from the AdnexMR Scoring System published in 2012.

See also