Impact of microbubble contrast on 2D strain quantification.

Area of Science:

• Cardiovascular imaging
• Echocardiography
• Myocardial mechanics

Background:

• Two-dimensional (2D) strain analysis using speckle tracking is a semi-automatic method for quantifying myocardial deformation.
• Microbubble contrast (MBC) agents alter echocardiographic speckle patterns, potentially impacting strain analysis, but their effect on speckle tracking requires further investigation.

Purpose of the Study:

• To assess the feasibility of 2D strain analysis on contrast-enhanced echocardiograms using a normal mechanical index (MI).
• To evaluate the impact of MBC on strain measurements and speckle tracking performance.

Main Methods:

• Twenty-nine patients with normal echocardiograms were included and categorized into high (HIQ) and low (LIQ) image quality groups.
• Standard apical loops were recorded before, during, and at 3 and 7 minutes after MBC infusion (SonoVue) at MI = 1.0.
• Left ventricular peak systolic strain (mean and regional) was calculated, and reproducibility and tracking performance were assessed.

Main Results:

• 2D strain analysis was possible during and shortly after MBC infusion.
• No significant changes in mean or regional left ventricular strain were observed over time.
• Tracking reproducibility worsened during and shortly after MBC infusion, particularly in the LIQ group. Tracking was impaired in the HIQ group during MBC but improved over time in the LIQ group.

Conclusions:

• 2D strain quantification is achievable with contrast-enhanced echocardiography.
• MBC does not significantly alter 2D strain measures.
• High concentrations of MBC can negatively affect the reproducibility and performance of speckle tracking algorithms.