MRI appearances of adnexal torsion:a report of 26 cases

Objective To investigate the features of magnetic resonance imaging (MRI) for adnexal torsion. Methods Total 26 cases of adnexal torsion confirmed by surgery pathology were reviewed retrospectively.All cases received ultrasonic inspection and MRI scan.And the results were compared with surgical. Results There were mesosalpinx cyst torsion (n=3),hydrosalpinx torsion (=1),primary ovarian torsion (n=4) and secondary ovarian mass torsion (n=18).MRI diagnosed 23 cases,missed 3 cases,with an accuracy rate of 88.5%(23/26).And it was higher than the rate of ultrasound 65.4%(17/26).MRI demonstrated abnormal masses in abdominal area in 26 cases.It connected with one side uterine horn and accessories.Two infants could not provide the clear imaging of the uterine.The torsional pedicle presented typical "beak sign" (n=12), "whirlpool sign" (n=12) and "disordered structure" (n=2).Beak sign and whirlpool sign exhibited as high signal intensity on diffusion weighted imaging (DWI)(9/10) and like twisted blood vessels enhancement (7/7).In 26 cases,there were adnexal torsion (n=27):cystic mass (n=16),solid-cystic mass (n=11).In T₂WI and SPIR,eccentric thickened wall or septa were observed in 12 cases;liquid-liquid levels were observed in 7 cases,the solid-cystic mass showed a mixed signal.It complicated with pelvic effusion (n=11),gestation (n=4),fibroid (n=4),teratoma of contra-lateral ovary (n=1),chocolate cyst of contra-lateral ovary (n=1) and the contralateral hydrosalpinx (n=1). Conclusion MRI performances of adnexal torsion have certain characteristics.The torsional pedicle can be clearly on MRI.MRI examination is a beneficial supplement to ultrasound.