spectral broadening
Doppler ultrasound phenomenon showing widening of the frequency spectrum due to turbulent flow or increased velocity gradients.
Full Definition
Spectral broadening represents the expansion of the Doppler frequency spectrum beyond normal laminar flow patterns, manifesting as filling-in of the spectral window on duplex ultrasound studies. This phenomenon results from turbulent flow, velocity aliasing, or increased shear rates typically associated with stenotic lesions, arteriovenous malformations, or prosthetic devices. The degree of spectral broadening correlates with stenosis severity and hemodynamic significance. Technical factors including gain settings, sample volume size, and Doppler angle can artificially create spectral broadening, requiring careful optimization and interpretation. Recognition of spectral broadening patterns aids in grading stenosis severity and identifying hemodynamically significant lesions.
Usage
Usage note: Distinguish between pathological and technical causes of spectral broadening in reports.
In Context
- "Marked spectral broadening at the carotid bifurcation indicated hemodynamically significant stenosis." — Carotid duplex ultrasound report
- "Absence of spectral broadening in the renal artery excluded significant stenosis despite anatomical irregularity." — Renal artery duplex study