In arterial Doppler studies, what does a biphasic waveform suggest?

A biphasic waveform in arterial Doppler studies is indicative of a relatively normal arterial flow pattern in healthy individuals but may suggest early signs of occlusion when observed in certain populations or conditions.

In typical arterial physiology, a biphasic waveform shows two distinct phases during the cardiac cycle, representing a return to baseline flow after each cardiac contraction. This pattern is expected in the arteries, particularly in the lower extremities, as it reflects normal arterial function in many cases. However, when a biphasic waveform appears in a context where triphasic or continuous patterns would be expected, it raises the concern of potential early arterial disease. This is often seen in patients who may be developing issues like atherosclerosis.

While triphasic waveforms indicate healthy, robust flow with quickly reversing diastolic flow, a negative change to a biphasic pattern suggests a reduction in perfusion or an impediment that could be due to early signs of occlusion. It indicates that there is some level of resistance in the artery, which may progressively lead to more significant blockages if not managed properly.

In contrast, a severe blockage would typically manifest as a monophasic waveform indicating significantly reduced or absent diastolic flow. In this case, the waveform