Diastolic pressure is the minimum pressure exerted on the arterial walls during the relaxation phase of the cardiac cycle, and it is the bottom number in a standard blood pressure measurement. In Doppler ultrasound, the end-diastolic velocity, the speed of blood flow at the end of diastole, is an important measurement used in many diagnostic calculations, including the resistive index and the pulsatility index, both of which help characterize blood flow in various organs. Abnormally elevated or reduced end-diastolic velocities can indicate vascular disease, and understanding the relationship between diastolic pressure and Doppler flow patterns is fundamental to performing and interpreting vascular ultrasound examinations.
Sonography Term