The most important Doppler criterion for diagnosing greater than 80% stenosis is?

The most important Doppler criterion for diagnosing greater than 80% stenosis is peak-systolic velocity. This parameter is critical because, as the degree of stenosis increases, the blood flow velocity in the vessel passing through the narrowed area increases significantly. Peak-systolic velocity is a direct indicator of this increased flow, as it reflects the highest speed achieved during the cardiac cycle when blood is ejected from the heart.

In the context of significant stenosis, velocities greater than certain thresholds (often cited around 230 cm/s for carotid artery stenosis) serve as a key diagnostic marker. The correlation between high peak-systolic velocities and the presence of severe stenosis makes this measurement highly reliable for vascular specialists in determining the extent of vascular occlusion.

Other velocity measurements, such as mean velocity or end-diastolic velocity, do provide information but are not as definitive as peak-systolic velocity when it comes to diagnosing high-grade stenosis. For instance, mean or time-average velocities can be influenced by various factors and may not reflect the peak flow accurately. End-diastolic velocity is typically lower and more variable, lacking the strong association with high-grade stenosis necessary for diagnosis. Therefore, peak-systolic velocity stands out as