Risk of Malignancy Index (RMI I/II/III)

Risk of Malignancy Index (RMI = U × M × CA-125) from the ultrasound-feature count, menopausal status, and CA-125; an RMI over 200 is the conventional high-risk threshold.

Open the calculator → Runs in your browser. Data leaves only if you deliberately send a problem report from the interactive tool.

Example

RMI variant
RMI I (Jacobs 1990)
Multilocular cyst
Yes
Solid areas
Yes
Ascites
Yes
Postmenopausal
Yes
CA-125
80 U/mL

Result: RMI 1 = U(3) x M(3) x CA-125(80) = 720: high risk (over 200).

The tool opens with these values already filled in. Replace them with your own.

What the result means

U / M scaling
RMI I: U 0/1/3, M pre 1 post 3. RMI II: U 1/4, M pre 1 post 4. RMI III: U 1/3, M pre 1 post 3.
> 200
conventional high-risk threshold prompting gyn-oncology referral.

What you enter

  • RMI variant (I / II / III)
  • Multilocular cyst
  • Solid areas
  • Bilateral lesions
  • Ascites
  • Intra-abdominal metastases
  • Postmenopausal
  • CA-125
How this is calculated
Formula
RMI = U x M x CA-125 (U/mL); features = multilocular cyst, solid areas, bilateral, ascites, metastases.

Jacobs I, Oram D, Fairbanks J, Turner J, Frost C, Grudzinskas JG. A risk of malignancy index incorporating CA 125, ultrasound and menopausal status for the accurate preoperative diagnosis of ovarian cancer. Br J Obstet Gynaecol. 1990;97(10):922-929; II/III per Tingulstad 1996/1999. Read the source ↗

A reference and educational tool. Not medical, legal, or financial advice, and not a substitute for clinician judgment.

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Built by Clay Good. Source on GitHub.