Detection of subcritical stenoses by Doppler spectrum analysis

Area of Science:

• Cardiovascular imaging
• Diagnostic ultrasound
• Hemodynamics

Background:

• Limited data exists on carotid Doppler signal spectral analysis sensitivity for subcritical stenotic lesions.
• Flow disturbances in carotid arteries are critical indicators of potential cardiovascular events.

Purpose of the Study:

• To evaluate the sensitivity of carotid Doppler signal spectral analysis in detecting flow disturbances from subcritical stenotic lesions.
• To assess the quantitative capabilities of spectral analysis for noninvasive stenosis detection.

Main Methods:

• Utilized spectral analysis on Doppler signals from canine infrarenal aorta models with 10-80% diameter reduction stenoses.
• Compared peak systolic frequency at stenosis sites with proximal sites to derive frequency ratios.
• Analyzed Doppler spectra at various distances distal to stenotic lesions.

Main Results:

• Spectral analysis reliably detected stenoses as small as 20% diameter reduction (peak frequency ratio ~1.5).
• A near-linear increase in peak frequency ratio was observed up to 50% stenosis (~2.1).
• Distal spectral analysis showed significant changes beyond 45% stenosis, with ratios increasing up to 65% stenosis (~1.64).

Conclusions:

• Doppler signal spectrum analysis demonstrates high sensitivity for detecting subcritical carotid arterial stenoses.
• The technique appears quantitative and noninvasive, suitable for clinical application.
• Spectral analysis effectively documents flow disturbances caused by varying degrees of stenosis.