Advanced MRI Assessment of Ovarian Torsion: A Pilot Surgical-Correlation Study of Ischemic Severity and Ovarian Viability

Abstract

To assess whether adding advanced MRI sequences, including diffusion-weighted imaging (DWI), apparent diffusion coefficient (ADC) mapping, three-dimensional constructive interference in steady state (3D-CISS), and susceptibility-weighted imaging (SWI), improves twisted pedicle visualization and supports assessment of ovarian viability in surgically confirmed ovarian torsion. This prospective pilot surgical-correlation study included 30 female patients presenting with acute lower abdominal or pelvic pain. All of them were later confirmed, during surgery, to have ovarian torsion. The study was carried out at Private Nursing Home Hospital in Baghdad, Iraq, from 1st April 2026 to 7th June 2026. All patients underwent pelvic MRI on a 1.5 T system during the emergency imaging workup. Routine MRI included T1-weighted, T2-weighted, and post-contrast fat-suppressed sequences when contrast was clinically permitted. DWI, ADC mapping, 3D-CISS, and SWI were then added as the advanced protocol. Two radiologists reviewed the images independently while blinded to the operative findings. MRI findings were correlated with intraoperative assessment of ovarian viability. Since only surgically confirmed torsion cases were included, specificity, positive predictive value, negative predictive value, and overall diagnostic accuracy were not calculated. The twisted pedicle was seen more often after adding the advanced sequences, increasing from 40.0% on routine MRI to 83.3% on advanced MRI. Diffusion restriction was present in 27 patients (90.0%) and was seen in all surgically non-viable ovaries. Mean ADC values were lower in non-viable ovaries than in viable ovaries (0.78 ± 0.10 vs. 1.21 ± 0.15 ×10⁻³ mm²/s; p < 0.01). An ADC value ≤0.9 ×10⁻³ mm²/s was associated with intraoperative non-viability, although it was treated only as an exploratory marker of ischemic severity rather than a validated cutoff. Inter-observer agreement was excellent for ovarian enlargement, diffusion restriction, and twisted pedicle visualization. In this pilot surgical-correlation study, advanced MRI added useful information beyond routine pelvic MRI in confirmed ovarian torsion. DWI with ADC mapping and 3D-CISS were the most useful additions, improving pedicle visualization and supporting assessment of ischemic severity. The proposed ADC threshold should remain cautious and needs external validation before broader clinical use.