In vascular ultrasound, a monophasic waveform describes a Doppler signal exhibiting a single phase of flow, often indicating significant arterial disease. This pattern lacks the characteristic triphasic or biphasic components of healthy vessels, where blood flow reverses during diastole. Its presence suggests severe stenosis or occlusion, as the vessel struggles to maintain adequate distal perfusion, leading to continuous forward flow without deceleration or reversal.
Identifying a monophasic waveform is crucial for diagnosing peripheral artery disease, critical limb ischemia, and other vascular pathologies. Sonographers and clinicians rely on this specific Doppler signature to assess disease severity and guide treatment decisions, emphasizing its importance in medical diagnostics and ultrasound interpretation.