Spectral Doppler is a form of Doppler ultrasound that displays blood flow information as a waveform graph, with velocity on the vertical axis and time on the horizontal axis. It provides detailed quantitative information about blood flow including peak systolic velocity, end-diastolic velocity, flow direction, and waveform shape. There are two types: pulse wave Doppler, which measures flow at a specific depth (sample volume), and continuous wave Doppler, which measures all flow along the beam path and can capture very high velocities without aliasing. Spectral Doppler is essential for grading arterial stenosis, assessing cardiac valve function, evaluating venous flow, and measuring indices like the resistive index and pulsatility index. The shape and characteristics of the spectral waveform provide valuable diagnostic information about both local and downstream vascular conditions.
Sonography Term