Pulse repetition and Nyquist calculator
Explore pulse repetition and nyquist with the method’s inputs, acquisition guidance and source references. Open the calculator to enter measurements or try an illustrative worked example.
Method
PRPmin ≈ 13 × depth; PRF = 1/PRP; Nyquist = PRF/2; duty = PD/PRP
Use the measurement units shown below. Some fields apply only to a selected method or condition; follow the interactive tool’s method choices. The interactive tool keeps missing measurements incomplete and provides its method-specific results and reference context.
Measurements and acquisition
Start from
Enter the measured value in the displayed unit
- Depth limit
- Known PRF
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Sample depth cm
Enter the measured value in the displayed unit
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Pulse repetition frequency kHz
Enter the measured value in the displayed unit
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Pulse duration · PD µs
Enter the measured value in the displayed unit · Optional
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Peak Doppler shift · |Δf| kHz
Enter the measured value in the displayed unit · Optional
- Confirm the variable matches the selected formula.
- Use the unit displayed beside the field.
- Keep measurements from the same representative hemodynamic state.
Sources and method context
Cambridge University Press · 2016 · Manual of Neurosonology · Ultrasound principles · Chapter 1 · Figures 1.3 and 1.6; PW Doppler and Nyquist, pp. 3–6
- Range and sampling · Chapter 1 · pulse timing and PW Doppler
Round-trip time limits conventional unambiguous PRF. Nyquist is half the PRF; CW removes pulsed aliasing while losing sample-depth selection.
- Duty factor · ASE Echocardiography Formula Review Guide Part 2 · principles of waves and sound
Duty factor is pulse duration divided by repetition period. The 13 µs/cm depth relation is a rounded soft-tissue approximation, not a scanner setting.
Catalogue review status: Source mapped · clinical sign-off pending
These pages describe the educational tool. Interpret measurements with the complete clinical context and the method’s acquisition limitations.