What might NOT be a reason for the discrepancy in stenosis percentage between duplex assessment and angiography?

The option regarding the color flow pulse repetition frequency (PRF) being set too high is indeed a reason that may NOT contribute to discrepancies in stenosis percentage between duplex ultrasound assessments and angiography. A high PRF can lead to a reduced sensitivity to detect small flow disturbances or low-velocity jets typically associated with stenosis. However, this factor alone does not directly cause a discrepancy in measurements when comparing duplex ultrasound to angiographic findings, since both imaging modalities evaluate blood flow dynamics in different ways.

In contrast, factors such as a long and smooth stenosis, using only one plane of visualization for angiography, and poor angle-correction in Doppler assessment can significantly impact the accuracy of the measurements. A long and smooth stenosis may not exhibit the same dramatic changes in velocity that would be apparent in a shorter or irregular stenosis, affecting the perceived stenosis percentage. Lack of comprehensive visualization in angiography could lead to underestimation or misrepresentation of the severity of the stenosis. Lastly, poor angle-correction in Doppler measurement can introduce errors due to cosine effects affecting the calculated velocities, which may lead to discrepancies with angiographic assessments. Understanding these distinctions helps clarify why the high PRF setting does not contribute substantially to discrepancies between the two