Rapid online quantification of left ventricular volume from real-time three-dimensional echocardiographic data

Area of Science:

• Cardiovascular Imaging
• Echocardiography
• Medical Technology

Background:

• Two-dimensional echocardiography (2DE) for left ventricular (LV) volume and ejection fraction (EF) assessment is limited by subjectivity, time, and inaccuracy.
• Geometric assumptions and foreshortened views in 2DE contribute to measurement variability.

Purpose of the Study:

• To validate a novel, rapid, online method for measuring LV volumes using real-time three-dimensional echocardiography (RT3DE).
• To establish cardiac magnetic resonance (CMR) as the reference standard for validation.
• To compare the accuracy and reproducibility of RT3DE with standard 2DE measurements.

Main Methods:

• Acquired CMR, 2DE, and RT3DE datasets from 50 patients.
• Calculated LV volumes (ESV, EDV) and EF using biplane method of disks for 2DE.
• Utilized prototype software for automated endocardial detection and voxel count-based volume calculation from RT3DE data.
• Compared 2DE and RT3DE measurements against CMR using linear regression and Bland-Altman analysis.

Main Results:

• RT3DE analysis was rapid (<2 min per patient).
• RT3DE showed high correlation with CMR (r=0.96-0.97) with small biases and narrow limits of agreement.
• 2DE measurements showed lower correlation with CMR (r=0.86-0.92), greater biases, and wider limits of agreement.
• RT3DE demonstrated significantly lower intra-observer and inter-observer variability compared to 2DE.

Conclusions:

• Semi-automated LV endocardial surface detection from RT3DE data is clinically suitable.
• RT3DE enables rapid, accurate, and reproducible LV volume measurements.
• RT3DE measurements are superior to conventional 2DE methods for LV volume and EF assessment.