Which Doppler ultrasound findings indicate arterial stenosis?

• A. Decreased velocity with smooth laminar flow.
• B. Increased peak systolic velocity at the stenosis, post-stenotic turbulence, spectral broadening; reduced distal diastolic flow.
• C. Normal Doppler waveform without turbulence.
• D. Laminar flow with increased diastolic flow.

Answer: (B)

Arterial stenosis shows a characteristic Doppler pattern where the flow speeds up as it enters the narrowed segment, then becomes disturbed downstream. The widened velocity at the stenosis happens because the same amount of blood must pass through a smaller opening, so the peak systolic velocity increases. After the narrowed area, the jet expands into the downstream vessel and becomes chaotic, producing post-stenotic turbulence and spectral broadening on the Doppler trace. Downstream, the diastolic portion of the waveform often diminishes because the narrowed segment adds resistance and dissipates energy, reducing forward flow in diastole. This combination—high velocity at the narrowing, post-stenotic turbulence with spectral broadening, and reduced distal diastolic flow—best indicates arterial stenosis.

Other patterns don’t fit stenosis: decreased velocity with smooth laminar flow suggests no narrowing; a normal waveform without turbulence indicates no stenosis; laminar flow with increased diastolic flow isn’t typical for a stenotic segment, which usually disturbs diastolic flow rather than enhancing it.