Spatial Coherence Adaptive Clutter Filtering in Color Flow Imaging-Part II: Phantom and In Vivo Experiments

Area of Science:

• Ultrasound imaging
• Medical signal processing
• Biomedical engineering

Background:

• Conventional color flow processing in ultrasound requires extensive operator adjustment of clutter filters and priority settings.
• Operator dependence can lead to suboptimal display and accuracy of color flow images, impacting diagnostic capabilities.
• Previous work introduced a framework for adaptive color flow processing based on backscatter spatial coherence.

Purpose of the Study:

• To evaluate the efficacy of coherence-adaptive clutter filtering (CACF) on experimental ultrasound data.
• To assess CACF's performance in both phantom models and in vivo studies of liver and fetal vessels.
• To compare CACF against conventional color flow processing methods.

Main Methods:

• Implementation of a novel framework for adaptive color flow processing using local backscatter spatial coherence measurements.
• Application of coherence-adaptive clutter filtering (CACF) to experimental data from tissue phantoms and in vivo subjects.
• Analysis of velocity estimation bias, dynamic range, and artifact reduction compared to conventional methods.

Main Results:

• In phantom studies, CACF increased the dynamic range of velocity estimates and reduced bias and artifacts from noise.
• Under in vivo conditions, CACF enabled direct visualization of vessels without extensive manual tuning of conventional processing parameters.
• The study identified specific failure modes of CACF and proposed potential mitigation strategies.

Conclusions:

• Coherence-adaptive clutter filtering (CACF) offers significant advantages over conventional color flow processing by reducing operator dependence and improving image quality.
• CACF effectively suppresses noise and preserves flow signals, leading to more accurate velocity estimations and enhanced vessel visualization.
• Further research and development are needed to address identified limitations and optimize CACF for widespread clinical application.