Try not to worry too much. They can't tell if it is cancer or not until they biopsy it. I am still in the waiting stages myself. I have had the ultra sound, transvaginal ultrasound, and the mri. They still don't know. Now, I go to see a gynocologist/oncologist so they can do surgery to look at it or biopsy it or something. I'll just prepare you right now, it is a waiting game. Good luck and keep us posted.
The time is not critical so please take a break from the worry. An MRI is good and will give greater definition on the solid small mass on the ovary. If surgery is suggested then you should it done by a gyn/oncologist.
Take care and please keep us posted on the outcome of the MRI.