Hello,
MRI is highly specific for abdominal conditions. Most MRIs of the abdomen also shoot images of the pelvic area, and if they did, then it would have shown ovarian cysts if they were there at the time of the MRI. However the best test for diagnosis is an ultrasound. So as your gynecologist has advised you can get a repeat ultrasound done.
It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.