What does the pulsatility index measure in vascular studies?

The pulsatility index is a significant measurement in vascular studies, particularly in assessing blood flow characteristics in arteries. It is calculated as the difference between the peak systolic velocity and the end diastolic velocity, divided by the mean velocity. This ratio provides insight into the degree of pulsatility in the blood flow, which is particularly relevant in evaluating blood flow dynamics in situations such as vascular occlusions, arterial stenosis, or other conditions affecting hemodynamics.

By analyzing the pulsatility index, clinicians can determine how well blood is flowing through the vascular system and assess the resistance the blood encounters as it moves through different segments of the arterial system. A high pulsatility index may indicate increased resistance, while a low index suggests normal conditions of blood flow, indicating an efficient vascular system. This measurement, therefore, plays a vital role in diagnosing and monitoring various vascular diseases and conditions.