Iron deposition in ovarian endometrioma evaluated by magnetic resonance imaging R2* non-invasively

RESEARCH QUESTION: Is surgery effective in decreasing iron deposition in the ovarian tissue surrounding an ovarian endometrioma? DESIGN: This cohort study was conducted in China between July 2023 and April 2024. Seventy-nine patients with ovarian endometriomas and 45 controls with other ovarian cyst types were enrolled. Magnetic resonance imaging using a relaxation sequence (MRI-R2*) has been proven to be a reliable method for detecting iron deposition. All participants underwent MRI-R2* preoperatively to detect the presence of iron in ovarian tissue, before surgical ovarian cystectomy. Additionally, patients with ovarian endometriosis underwent MRI-R2* 3 months after surgery. The end points were changes in iron content, as reflected by the R2* value of ovarian tissue, surrounding an ovarian endometrioma. RESULTS: The preoperative R2* value of the affected-side ovarian tissue in the ovarian endometriosis group was significantly higher than that in the control group (27.00 [22.50-32.25] Hz versus 23.00 [13.50-26.36] Hz; P = 0.012). In the ovarian endometriosis group, the affected-side ovarian tissue had higher R2* values than the intact side ovarian tissue before (27.00 [22.50-32.25] Hz versus 19.19 [14.43-24.12] Hz; P = 0.019) and after (27.13 [21.80-31.50] Hz versus 21.96 [19.00-27.53] Hz; P = 0.015) surgery. No significant changes were observed in the R2* values of the affected-side ovarian tissue after surgery. CONCLUSIONS: In patients with ovarian endometriomas, the affected-side ovarian tissue demonstrated no reduction in iron content within 3 months of ovarian cystectomy. Cystectomy alone is inadequate for complete elimination of local iron deposition. Serial MRI-R2* monitoring could serve as an objective modality for assessing postoperative iron deposition dynamics.