O-RADS MRI score | Risk category | Positive predictive value for malignancy | Remarks |
0 | Incomplete evaluation | – | – |
1 | Normal ovaries | – | No ovarian lesion |
| | | Simple cyst < or equal to 3 cm in premenopausal women |
| | | Hemorrhagic cyst < or equal to 3 cm in premenopausal women |
| | | Corpus luteum with or without hemorrhage < or equal to 3 cm in premenopausal women |
2 | Almost certainly benign | < 0.5% | Cyst: unilocular, any type of fluid content. No wall enhancement. No enhancing solid tissue |
| | | Cyst: unilocular, simple or endometriotic fluid content. Smooth enhancing wall. No enhancing solid tissue |
| | | Lesion with lipid content. No enhancing solid tissue |
| | | Lesion with dark T2 or DWI solid component. Homogeneously hypo intense in both T2 and DWI |
| | | Dilated fallopian tube – simple fluid content. Thin smooth walls with enhancement. No enhancing solid tissue |
| | | Para-ovarian cyst: any type of fluid. Thin, smooth wall enhancement. No solid enhancing tissue |
3 | Low risk | Around 5% | Cyst: unilocular – proteinaceous, hemorrhagic or mucinous fluid content. Smooth enhancing wall. No enhancing solid tissue |
| | | Cyst: multilocular, any type of fluid. No lipid content. Smooth septa and wall with enhancement. No enhancing solid tissue. |
| | | Lesion with solid tissue. Low risk curve on DCE MRI. |
| | | Dilated fallopian tube. Non simple fluid – thin walls. Simple fluid with thick walls. No enhancing solid tissue |
4 | Intermediate risk | Around 50% | Lesion with solid tissue. Intermediate risk curve on DCE MRI. Solid tissue enhancing less than myometrium |
| | | Lesion with lipid content. Large volume enhancing solid tissue |
5 | High risk | Around 90% | Lesion with solid tissue. High risk curve on DCE MRI. Tissue enhancing >myometrium at 30-40s |