Doppler Resistive Index Calculator

cm/s
cm/s
Health

The Doppler Resistive Index Calculator computes the resistive index (RI) from peak systolic velocity and end-diastolic velocity, used in vascular and renal ultrasound. For clinical education only.

Rates and fees change frequently. Always confirm the current figures with the official authority before relying on this result.

Formula

RI = (PSV − EDV) ÷ PSV
  • A renal RI above about 0.70 is often considered elevated.
  • RI reflects downstream vascular resistance.

PSV 60, EDV 20

Inputs
  • Peak Systolic Velocity (PSV): 60 cm/s
  • End-Diastolic Velocity (EDV): 20 cm/s

(60 − 20) ÷ 60 = 0.67.

Frequently asked questions

What is a normal resistive index?
In the kidney, an RI up to about 0.70 is generally considered normal; higher values suggest increased vascular resistance.