Where is the highest peak systolic velocity (PSV) typically seen in stenotic vessels?

The highest peak systolic velocity (PSV) in stenotic vessels is typically seen at the narrowest part within the stenosis. This phenomenon occurs due to the principles of fluid dynamics, specifically Bernoulli's principle, which states that as the diameter of a vessel decreases, the velocity of blood flow increases to maintain continuity. Thus, as blood flows through the narrowed section of the vessel, there is a significant increase in velocity at this point.

In a stenotic area, the blood must pass through a reduced diameter, creating increased resistance and velocity. The peak systolic velocity measured at this location is crucial for assessing the severity of the stenosis; higher velocities correlate with more severe obstructions. The area at the entrance of the stenosis or post-stenosis can show different flow characteristics, but they do not reach the peak velocities observed at the point of the greatest narrowing.