Radiology Spotters Collection

Head Start Your Radiology Residency [Online] ↗️

O-RADS Ultrasound Calculator v2022

Disclaimer: The author makes no claims of the accuracy of the information contained herein; this information is for educational purposes only and is not a substitute for clinical judgment. This calculator is based upon the American College of Radiology (ACR) classification, but this calculator is not officially endorsed by the ACR or reviewed by the ACR committee. Kindly refer to the ACR website for latest updates.

I have now added management guidelines to the results. Feedback and suggestions welcome.

Ovarian lesions

Normal Ovary
    No lesion
  • Physiologic cyst
  • Follicle
  • Corpus Luteum

Classic Benign Lesion
For any atypical features, use other lexicon descriptors

Quick References:
O-RADS US Assessment Categories Tables
Assessment Categories – Algorithm
O- RADS US Lexicon Terms Table

Key Terms from O-RADS 2022 Update Table :

  • Smooth and irregular: refer to inner walls/septation(s) for cystic lesions, and outer contour for solid lesions; irregular inner wall for cysts = <3 mm in height.
  • Solid: excludes blood products and dermoid contents; solid lesion = ≥80% solid; solid component = protrudes ≥3 mm (height) into cyst lumen off wall or septation
  • Shadowing: must be diffuse or broad to qualify; excludes refractive artifact
  • pp = papillary projection; subtype of solid component surrounded by fluid on 3 sides
  • CS = color score; degree of intralesional vascularity; 1 = none, 2 = minimal flow, 3 = moderate flow, 4 = very strong flow
  • Bilocular = 2 locules; multilocular = ≥3 locules; bilocular smooth cysts have a lower risk of malignancy, regardless of size or CS
  • Postmenopausal = ≥1 year amenorrhea (early: <5 yrs; late: ≥5 yrs); if uncertain or uterus surgically absent, use age >50 years (early = >50 yrs but <55 yrs, late: ≥55 yrs)
  • *Shorter imaging follow-up may be considered in some scenarios (eg, clinical factors).
  • If smaller (≥10–15% decrease in average linear dimension), no further surveillance.
  • If stable, follow-up US at 24 months from initial exam. If enlarging (≥10–15% increase in average linear dimension), consider follow-up US at 12 and 24 months from initial exam, then management per gynecology. For changing morphology, reassess using lexicon descriptors. Clinical management with gynecology as needed.
  • **There is a paucity of evidence for defining the optimal duration or interval for imaging surveillance. Shorter follow-up may be considered in some scenarios. (eg, clinical factors). If stable, follow-up at 12 and 24 months from initial exam, then as clinically indicated. For changing morphology, reassess using lexicon descriptors.
  • † MRI with contrast has higher specificity for solid lesions, and cystic lesions with solid component(s).
  • †† Not due to other malignant or non-malignant etiologies; specifically, must consider other etiologies of ascites in categories 1–2.
  • Evidence does support an increased risk of malignancy in endometriomas following menopause and those present greater than 10 years.

The O-RADS (Ovarian-Adnexal Reporting and Data System) ultrasound calculator is a tool designed to assist radiologists and healthcare professionals in the assessment and risk stratification of adnexal masses.

What is the O-RADS Ultrasound Calculator?

The O-RADS ultrasound calculator is a web-based application that incorporates the ACR’s O-RADS risk stratification system. By inputting relevant imaging findings, the calculator assigns a numerical score ranging from 0 to 5, each representing a specific level of risk for malignancy.

O-RADS ScoreRisk CategoryPositive Predictive Value (PPV) for Malignancy
0Incomplete EvaluationN/A
1Normal OvariesN/A
2Almost Certainly Benign< 0.5%
3Low Risk≈ 5%
4Intermediate Risk≈ 50%
5High Risk≈ 90%

The assigned score is based on a comprehensive analysis of various ultrasound features, including lesion morphology, solid components, and vascular flow characteristics.

Benefits of the O-RADS Ultrasound Calculator

  1. Standardized Reporting: The calculator promotes consistent and standardized reporting of adnexal masses, facilitating clear communication among healthcare professionals.
  2. Risk Stratification: By assigning a numerical score, the calculator helps stratify the risk of malignancy, guiding appropriate management and follow-up strategies.
  3. Improved Patient Care: The calculator aids in identifying high-risk lesions that may require prompt intervention, while also reducing unnecessary procedures for low-risk lesions.
  4. Educational Resource: The calculator serves as a valuable educational tool, assisting in the training of radiology residents and fellows in adnexal mass assessment.
  5. Research Facilitation: The standardized reporting system enables multicenter collaborations and facilitates research efforts in ovarian cancer and adnexal pathologies.

How to Use the O-RADS Ultrasound Calculator

The O-RADS ultrasound calculator is user-friendly and can be accessed through various platforms, including web browsers and mobile applications. Here’s a general overview of the steps involved:

  1. Perform a detailed ultrasound evaluation of the adnexal mass, documenting relevant imaging features.
  2. Access the O-RADS ultrasound calculator and input the required information, such as lesion morphology, solid components, and vascular flow characteristics.
  3. Review the assigned O-RADS score and its corresponding risk category.
  4. Interpret the results in conjunction with clinical findings and refer to the ACR’s management recommendations for appropriate patient care and follow-up.


The O-RADS ultrasound calculator is a powerful tool that streamlines the assessment and management of adnexal masses. By promoting standardized reporting and risk stratification, it represents a significant step forward in improving patient outcomes and advancing research in ovarian and adnexal pathologies. As the adoption of this calculator continues to grow, healthcare professionals can expect enhanced interdisciplinary communication, more informed clinical decision-making, and ultimately, better patient care.

For some reason the preferred search term for O-RADS is o’rads. Probably an indexing error from Google.


  1. O-RADS US Risk Stratification and Management System: A Consensus Guideline from the ACR Ovarian-Adnexal Reporting and Data System Committee.
  2. A simplified approach to ovarian lesions based on the O-RADS US risk stratification and management system

Last updated on May 16,2024

Wish to be a BETTER Radiologist? Join 14000 Radiology Colleagues !

Enter your email address below to access HIGH YIELD radiology content, updates, and resources.

Email Newsletter Subscription Pop Up

No spam, only VALUE! Unsubscribe anytime with a single click.