Diffusion-weighted imaging of ovarian torsion: Usefulness of apparent diffusion coefficient (ADC) values for the detection of hemorrhagic infarction

摘要

Purpose: We undertook this study to evaluate the need for diffusion-weighted (DW) magnetic resonance (MR) imaging in detecting hemorrhagic infarction following ovarian torsion. Methods: The study included 14 consecutive patients aged 12 to 74 years (average age, 36 years) with surgical confirmation of ovarian torsion who underwent 1.5-tesla MR imaging. Pathologically, hemorrhagic infarction was found in 7 patients. We retrospectively reviewed signal intensity on T1-, T2-, and diffusion-weighted images and apparent diffusion coefficients (ADCs) in swollen ovarian stroma. Results: Fallopian tube thickening was seen in all patients. In patients with ovarian cystic lesion, maximum cyst wall thickness was significantly higher in patients with hemorrhagic infarction (mean, 13.5 ± 4.1 mm) than those without (mean, 5.0 ± 1.0 mm) (P .05). Signal intensity did not differ significantly on T1-weighted, T2-weighted, and DW images between patients with and without hemorrhagic infarction. ADCs were significantly lower in patients with hemorrhagic infarction (1.20 ± 0.50 [× 10-3 mm2/s]) than those without (2.04 ± 0.26 [× 103 mm2/s]) (P .01). With an ADC threshold of 1.80 [× 10-3mm2/s], sensitivity for hemorrhagic infarction was 0.88 (7 of 8), and specificity was 1.00 (6 of 6). Conclusion: ADC measurements were useful for detecting hemorrhagic infarction in patients with ovarian torsion.