Improving diagnostic performance of O-RADS MRI: semi-quantitative intensity curves vs visual assessment of enhancement.

Abstract

O-RADS MRI improves differentiation of benign adnexal lesions managed by a gynecologist and malignant lesions managed by a gynecologic oncologist. To compare O-RADS MRI visual assessment (VA) of mass enhancement with a semi-quantitative intensity curve of enhancement (SIC), a modified manual version of the time intensity curve. We conducted a retrospective MRI review of patients who underwent surgical resection between January 2008 and December 2018 at two referral centers. O-RADS MRI score was assigned by two radiologists with different experience. O-RADS score ≥ 4 was considered suspicious for malignancy. Per-lesion diagnostic accuracy and impact on surgical management were compared between VA and SIC in lesions with solid components. Inter/intra-reader agreement was assessed. Borderline and invasive lesions were considered malignant. Three hundred forty-one adnexal masses in 321 women (ages 18-89) were assessed; 35.2% (120/341) of the masses were malignant. Ninety-six and two-tenths percent had some solid component (329/341). O-RADS MRI using standard VA had a sensitivity, specificity, and PPV of 0.95 (CI: 0.89-0.98), 0.84 (CI: 0.79-0.89), and 0.77 (CI:0.69-0.83), respectively. Use of SIC improved specificity (0.92 [CI: 0.88-0.95, p = 0.007) and PPV (0.90 [CI: 0.83-0.95], p = 0.002). Including SIC in O-RADS MRI would have reduced the proportion of benign lesions operated by gyneoncologists from 16% [54/341] to 9% [1/341] (p = 0.0001). O-RADS score, SIC, and VA assessment had a moderate to high inter- and intra-reader agreement (Kappa 0.63-0.85). O-RADS MRI exhibited high diagnostic performance in triage of adnexal masses. Incorporation of SIC increased the specificity and PPV of O-RADS MRI with high inter- and intra-reader agreement of SIC interpretation. Question Differentiation of benign from malignant adnexal masses is important for surgical triage. Findings Integration of semiquantitative intensity curves (SIC) into O-RADS MRI improved specificity when compared to conventional VA. Clinical relevance Integration of SIC into O-RADS MRI improves surgical triage of patients.