pulsatility index

The pulsatility index (PI) is a measurement used in medical imaging, particularly ultrasound, to assess blood flow characteristics within vessels or organs. It reflects the resistance to blood flow, calculated by comparing the difference between peak and resting blood flow velocities to the average velocity over time. A higher PI indicates greater resistance, which can suggest issues like narrowing or blockage, while a lower PI indicates more flexible, healthy blood flow. It helps doctors evaluate circulatory health and identify potential problems with blood supply.