RMI Calculator

RMI Calculator

Ultrasound Features(U)

Menopause Status (M score)

Ca 125 (Ca125 Score)

RMI is a tool used for ovarian cancer detection. It combines three pre-surgical features: serum CA125 (CA125), menopausal status (M) and ultrasound score (U). The formula is RMI = U x M x CA125.

Note, there are various RMI scoring systems (RMI 1, RMI 2, RMI 3 and RMI 4), with similar accuracies. This calculator uses the original RMI 1 from Jacobs et al, 1990, which is what ADHB uses and is the most widely used one.

  • U Score: The ultrasound result is scored 1 point for each of the following characteristics: multilocular cysts, solid areas, metastases, ascites and bilateral lesions. 0 = U score of 0, 1 = U score of 1, 2-5 = U score of 3
  • M Score: The menopausal status is scored as 1 = pre-menopausal and 3 = post-menopausal. The classification of ‘post-menopausal’ is a woman who has had no period for more than 1 year or a woman over 50 who has had a hysterectomy.
  • Ca125 Score: Serum CA125 is measured in IU/ml and the actual value is used

Cut offs
Cut-off of 200: Sensitivity 78%, specificity 87%. ADHB uses a cut-off of 200
Cut-off of 250: Sensitivity 70%, specificity 90%. Some centres use this cut off.

Historical Validation Data
Less than 25 – < 3% risk of malignancy
25 to 250 – around 20% risk of malignancy
Over 250 – around 75% risk of malignancy


Jack of all organs, master of none,

though oftentimes better than master of one.