Torsion of a hyperstimulated ovary during pregnancy: a potentially difficult diagnosis.

Ovarian torsion in a pregnant infertility patient is an important and difficult diagnosis to make. We present two cases of torsed hyperstimulated ovaries where grey scale and Doppler sonographic evaluation were inconclusive. In one case, magnetic resonance imaging (MRI) was used to make the diagnosis. In the second case, physical findings observed during the ultrasound exam were diagnostic. We think these two cases are good teaching examples of how to approach this difficult diagnosis and emphasize that MRI and physical exam skills are useful adjuncts to ultrasound in the evaluation of a pregnant patient.