A novel magnetic resonance imaging index to evaluate ovarian reserve in endometrioma patients: the ovary to endometrioma volume index

Background: Ovarian endometrioma is a common form of endometriosis associated with chronic pelvic pain, infertility, and diminished ovarian reserve. Although anti-Müllerian hormone (AMH) is widely used to evaluate ovarian reserve, it does not reflect structural ovarian changes. To introduce and assess the Ovary to Endometrioma Volume Index (OEVI), calculated from magnetic resonance imaging (MRI), as noninvasive marker of ovarian reserve in women with endometrioma. Methods: Fifty women of reproductive age with ovarian endometrioma were included. Patients with menopause, primary ovarian failure, or prior endometrioma surgery were excluded. Serum AMH, follicle stimulating hormone (FSH), luteinizing hormone (LH), and cancer antigen 125 (Ca-125) were measured. Ovarian and endometrioma volumes were quantified on pelvic MRI, and OEVI was calculated as total ovarian volume divided by total endometrioma volume. Spearman correlation and multivariable regression analyses were performed. Results: = 0.035) demonstrated inverse associations. The regression model explained 42% of OEVI variability. The regression model explained 42% of OEVI variability. Conclusion: OEVI demonstrates significant associations with established hormonal markers and may represent a promising structural adjunct in ovarian reserve assessment. Its association with AMH and inverse relationship with gonadotropins suggest that OEVI reflects both structural and functional ovarian capacity and may support individualized clinical management and fertility counseling.