Switzerland: The subsequent use of the O-RADS (Ovarian-Adnexal Reporting and Data System) MRI lexicon to characterize pelvic MRI findings for indeterminate adnexal lesions has high diagnostic performance, according to results from a recent meta-analysis. O-RADS MRI 4 and 5 lesions were shown to have higher malignancy rates than predicted.
The study's findings appeared in Radiology, the journal of the Radiological Society of North America (RSNA).

Transvaginal ultrasound-indeterminate adnexal lesions remain a critical indication for gynecologic surgery. Through the use of the O-RADS MRI (magnetic resonance imaging) lexicon, MRI can serve as a problem-solving tool. O-RADS MRI lexicon is based on the ADNEX MRI scoring system.
As the diagnosis of eight to 30 percent of incidental adnexal lesions remains elusive with transvaginal ultrasound, Andrea Cozzi and colleagues performed a meta-analysis to evaluate the subsequent use of the Ovarian-Adnexal Reporting and Data System MRI classification to characterize pelvic MRI findings for indeterminate adnexal lesions.
For this purpose, the researchers performed a systematic literature search from 2013 to 2022. It included studies reporting pelvic MRI use with the O-RADS or ADNEX MRI systems to characterize ultrasound-indeterminate adnexal lesions, with pathologic examination and follow-up as the reference standard.
The authors investigated the effects of covariates on heterogeneity, and diagnostic performance was investigated. The bivariate random-effects model was used to obtain the summary estimates of diagnostic performance. In contrast, a random-effects model was used to get category-wise summary malignancy rates of O-RADS MRI 2, 3, 4, and 5 lesions.
The inclusion criteria were met by thirteen study parts from 12 studies comprising 3731 women with 4520 adnexal lesions.
Key findings of the study include:
· Diagnostic performance meta-analysis for 4012 lesions found a 91% summary specificity and 92% summary sensitivity.
· The meta-analysis of malignancy rates for 3641 lesions revealed summary malignancy rates of 0.1% among O-RADS MRI 2 lesions, 6% among O-RADS MRI 3 lesions, 60% among O-RADS MRI 4, and 96% among O-RADS MRI 5 lesions.
"Pelvic MRI interpreted with the O-RADS MRI lexicon had a high diagnostic performance for the characterization of US-indeterminate adnexal lesions," the researchers wrote. "Summary estimates of malignancy rates in the categories O-RADS MRI 4 and O-RADS MRI 5 were higher than predicted ones."
Reference:
The study titled "O-RADS MRI: A Systematic Review and Meta-Analysis of Diagnostic Performance and Category-wise Malignancy Rates" was published in the journal Radiology.
DOI: https://doi.org/10.1148/radiol.220795