Nakagami-m Parametric Imaging for Atherosclerotic Plaque Characterization Using the Coarse-to-Fine Method

Area of Science:

• Medical Imaging
• Biophysics
• Ultrasound Technology

Background:

• Atherosclerotic plaques pose significant health risks, and accurate characterization is crucial for effective treatment.
• Current ultrasound methods for plaque analysis have limitations in resolution and accuracy.
• The Nakagami model offers a statistical framework for analyzing ultrasound backscattered signals.

Purpose of the Study:

• To develop and validate a novel imaging technique for improved atherosclerotic plaque characterization.
• To enhance ultrasound image resolution and accuracy in distinguishing different plaque types.
• To investigate the potential of Nakagami-m parametric imaging for plaque composition analysis.

Main Methods:

• Utilized the Nakagami model to analyze statistical differences in ultrasound backscattered signals.
• Proposed the coarse-to-fine based on maximum likelihood estimation (CTF-BOW) method for Nakagami-m parametric imaging.
• Validated the CTF-BOW method through simulations and preliminary in vivo studies (n=45).

Main Results:

• The CTF-BOW method demonstrated superior precision, smoothness, and resolution compared to the sliding window method in simulations.
• Preliminary in vivo results showed distinct, non-overlapping ranges of the m parameter for calcified, mixed, and echolucent plaques.
• The Nakagami-m parameter (m) was found to correlate with plaque composition, indicating its potential for characterization.

Conclusions:

• The CTF-BOW method significantly enhances ultrasound image resolution for atherosclerotic plaque characterization without compromising accuracy.
• Nakagami-m parametric imaging can effectively differentiate between calcified, mixed, and echolucent plaques.
• The Nakagami-m parameter holds promise as a biomarker for assessing plaque composition and aiding clinical diagnosis.