This tool was designed to help demonstrate the relationships between MR PISA measurement variables and the calculated effective regurgitant orifice area (EROA) and regurgitant volume (RVol).

Adjust these values:

150

This determines the RVol calculation.

Shell area: cm2

Shell flow: ml/sec

EROA: cm2 ()

RVol: ml ()

500

This determines the EROA- which affects the RVol calculations.

Shell area: cm2

Shell flow: ml/sec

EROA: cm2 ()

RVol: ml ()

38.5

This determines the shell flow- which affects the EROA & RVol calculations.

Shell area: cm2

Shell flow: ml/sec

EROA: cm2 ()

RVol: ml ()

50

This determines the shell area- which affects ...everything!

Shell area: cm2

Shell flow: ml/sec

EROA: cm2 ()

RVol: ml ()

Notes:

The shell area is calculated as 2 * pi * radius squared;

The shell flow is calculated as shell area * va;

The EROA is calculated as shell flow ÷ MR velocity;

The regurgitant volume (RVol) is calculated as EROA * MR VTI;

Also: the EROA and RVol still need context. For instance, is a regurgitant volume of 50 ml a little or a lot? If the forward stroke volume is 50 ml, it is a lot, but what if the forward stroke volume is 100ml? Calculation of the regurgitant fraction (RF) adds that context, but is beyond the scope of this simple demonstration.