MPS model web calculator

Noninvasive risk estimation for HREVs

A simple ultrasound-based calculator using portal vein velocity and spleen volume to estimate the probability of high-risk esophageal varices (HREVs) in hepatitis-related cirrhosis.

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Measurement note for PVV

PVV should be measured under standardized spectral Doppler ultrasound conditions before entering the value into this calculator.

The patient should be examined in the supine position and instructed to breathe quietly.

The portal vein should be localized using B-mode and color Doppler ultrasound before spectral Doppler measurement.

The Doppler sampling gate should be positioned at the center of the portal vein lumen and adjusted according to the vessel diameter to avoid inclusion of the vessel wall.

Doppler angle correction should be applied when necessary, with the insonation angle kept at ≤60° whenever possible.

Blood flow velocity should be recorded at the end of quiet expiration using stable Doppler waveforms for several seconds.

Three consecutive stable measurements should be obtained and averaged.

The averaged PVV value should then be entered into the calculator.

Spleen volume calculation

SV should be calculated from B-mode ultrasound measurements using the prolate ellipsoid formula.

SV = length × width × thickness × 0.523

Risk calculation formula

The calculator uses the mixed PVV-SV model. The linear predictor is converted into the predicted probability of HREVs using the logistic function.

MPS model linear predictor
LP = -2.1986338
     - 0.78599659 × PVV
     + 0.030179728 × SV
     - 9.5882394 × 10^-8 × max(SV - 241.98092, 0)^3
     + 1.5170803 × 10^-7 × max(SV - 439.12097, 0)^3
     - 5.5825639 × 10^-8 × max(SV - 777.71557, 0)^3

P(HREVs) = 1 / [1 + exp(-LP)]

Risk interpretation

The categories below provide a clinically oriented interpretation and should be considered together with the patient’s overall clinical context.

Rule-out range Predicted probability < 0.291. Lower probability of HREVs.
Indeterminate range Predicted probability 0.291–0.488. Further clinical assessment is recommended.
Rule-in range Predicted probability ≥ 0.489. Higher probability of HREVs.