Can an MRI tell if an ovarian cyst is benign?

For several common types, yes. The radiologists can recognise findings that are very likely benign, meaning not cancer:

• simple fluid-filled cysts and endometriomas (cysts caused by endometriosis) with no solid parts
• dermoid cysts, which contain fat
• solid lumps that look evenly dark on T2 and diffusion images

In the international O-RADS MRI system, findings like these carry a cancer risk below 0.5%. A formal O-RADS score needs contrast, so we don't give one. Anything with other solid parts or a complex structure stays unclear on this scan: we'll let you know and suggest seeing your gynaecologist for further tests.