Catherine H. Phillips, MD¹, Yang Guo, MD², Loretta M. Strachowski, MD³, Priyanka Jha, MD⁴, Caroline Reinhold, MD5^5,6, and Rochelle F. Andreotti, MD⁸

Abstract
The American College of Radiology (ACR) Ovarian-Adnexal Reporting and Data System (O-RADS) lexicon and risk assessment tool
for ultrasound (US) provides a framework for characterization of ovarian and adnexal pathology with the ultimate goal of harmonizing
reporting and patientmanagement strategies. Since the firstO-RADSUS publication in 2018, multiple validation studies have shownORADS
US to have excellent diagnostic accuracy, with the majority of these studies using O-RADS 4 as the optimal cut-off for detecting
ovarian cancer. Most of the existing validation studies include a dedicated training phase and confirmthatORADS US categories and
lexicon descriptors are associated with high level inter-read agreement, regardless of radiologist training level or practice experience.
O-RADS US has a similar inter-reader agreement when compared to Gynecologic Imaging Reporting and Data System (GIRADS),
Assessment of Different Neoplasias in the adnexa (ADNEX), and International Tumor Analysis Group (IOTA) simple rules. System
descriptors have been shown to correlate with expected malignancy rates and the O-RADS US risk stratification system has been
shown to perform in the expected range of malignancy risk per category. Further directions will focus on clarifying governing concepts
and lexicon terminology as well as further refining risk stratification categories based on data from published validation studies.

R´esum´e
R´esum´eL’outil d’´evaluation du risque et le lexique du système O-RADS (Ovarian-Adnexal Reporting and Data System) de
l’American College of Radiology (ACR) pour l’´echographie (US) procurent un cadre de d´efinitions de la pathologie ovarienne et
annexielle dans le but ultime d’harmoniser les rapports et les strat´egies de gestion des patientes. Depuis la première publication de
l’O-RADS US en 2018, de nombreuses ´etudes de validation ontmontr´e que la pr´ecision diagnostique de ces outils ´etait excellente,
la majorit´e des ´etudes utilisant O-RADS 4 comme seuil optimal de d´etection du cancer de l’ovaire. La plupart des ´etudes de
validations existantes incluent une phase de formation qui lui est consacr´ee et confirment que les cat´egories de l’O-RADS US et les
termes descriptifs de son lexique sont associ´es `a un taux ´elev´e de concordance entre lecteurs, ind´ependamment du niveau de
formation ou d’exp´erience professionnelle des radiologistes. Le niveau de concordance entre lecteurs avec l’O-RADS US ´etait
comparable aux règles simples du GI-RADS (Gynecologic Imaging Reporting and Data System), le système de donn´ees et de
rapports d’imagerie en gyn´ecologie, d’ADNEX (Assessment of DifferentNeoplasias in the adnexa) pour l’´evaluation des diff´erentes
n´eoplasies des annexes et d’IOTA (International Tumor Analysis Group), le groupe international d’analyse des tumeurs. Il a ´et´e
d´emontr´e que les descripteurs du système sont en corr´elation avec les taux attendus de malignit´e et les performances du système
de stratification du risque de l’O-RADS US se sont av´er´ees ˆetre dans la plage attendue du risque de malignit´e par cat´egorie.

¹ Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN, USA.
² Department of Radiology, Brigham and Women’s Hospital, Boston, MA, USA
³ Department of Radiology and Biomedical Imaging, Department of Obstetrics, Gynecology, and Reproductive Sciences, University of California, San Francisco,
CA, USA
⁴ Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
⁵ Department of Radiology, McGill University Health Centre, McGill University, Montreal, QC, Canada.
⁶ Co-Director, Augmented Intelligence Precision Health Laboratory, Research Institute of the McGill University Health Center, Montreal, Canada
⁷ Montreal Imaging Experts Inc., Montreal, Canada
⁸ Department of Radiology and Radiological Sciences, Department of Obstetrics and Gynecology, Vanderbilt University Medical Center, Nashville, TN, USA

Corresponding Author:
Caroline Reinhold, MD, Department of Radiology, 1001 Decarie Boul, Montreal, QC, Canada H4A 3J1
Email: caroline.reinhold@mcgill.ca