Which statement best describes criteria for diagnosing graft stenosis?

• A. 2:1 increase
• B. All three factors collectively
• C. Severe post-stenotic turbulence
• D. Focal velocity acceleration

Answer: (B)

Graft stenosis is diagnosed most reliably when multiple sonographic signs are considered together rather than relying on a single finding. When a graft narrows, the flow must speed up at the narrowed segment, so you’d expect a twofold rise in peak systolic velocity compared with the pre-stenotic segment. You’d also look for focal velocity acceleration right at the narrowed area, which points to a localized obstruction. Distal to the stenosis, flow typically becomes disturbed and turbulent, producing severe post-stenotic turbulence on Doppler and spectral broadening. Because each sign can be influenced by technique, angle, or other variables, recognizing all three together increases diagnostic accuracy. If you only relied on one criterion, you could misclassify flow changes that arise from non-stenotic factors. That’s why the best answer is to consider all three factors collectively.