Pulsed Wave (PW) and Spectral Analysis Optimization

This set of flashcards covers principles and tools for optimizing Pulsed Wave (PW) Doppler and Spectral Analysis, including sample volume placement, steering, and waveform visualization settings.

Pulsed Wave (PW) Doppler beam steering

The beam should be steered with respect to the angle of the vessel.

Sample volume/gate placement

The gate should be placed in the center of the vessel.

Sample volume/gate "arms"

These should be positioned parallel to the flow.

Pulsed Wave (PW) tools

A set of tools including steer, $SV/gate$, and angle correct.

Spectral Analysis tools

A set of tools for waveform optimization including gain, scale, baseline, and calipers.

Scale optimization

Should be set so that the entire waveform can be visualized.

Baseline optimization

Preferred to be high enough to allow some space below the waveform.

Acoustic window

Should be visualized if the vessel is normal, indicating no spectral broadening.

Peak Systolic Velocity (PSV)

The maximum velocity measured during systole, exemplified by values such as $-143\,cm/s$ or $88.30\,cm/s$.

End Diastolic Velocity (EDV)

The velocity measured at the end of diastole, exemplified by values such as $-27.1\,cm/s$ or $23.21\,cm/s$.

Resistive Index (RI)

A calculated metric from spectral analysis, with examples in the notes such as $0.74$, $0.79$, and $0.49$.

S/D ratio

The ratio of systolic to diastolic flow, with examples such as $3.80$, $4.70$, and $1.97$.

SV/Gate Size

The size of the sample volume gate, commonly adjusted to values such as $0.5\,mm$, $1.5\,mm$, $2.0\,mm$, or $3.0\,mm$.

Angle Correct (AC)

An adjustment used to align the Doppler beam with flow direction, typically set at or below $60^{\circ}$ (e.g., $60^{\circ}$, $50^{\circ}$, or $41^{\circ}$).

Triphasic flow

The characteristic flow pattern shown for LE Arterial (Lower Extremity Arterial) vessels.