Cyclic variation of integrated backscatter: dependence of time delay on the echocardiographic view used and the
A E Finch-Johnston1, H M Gussak, J Mobley
1Department of Physics and the Cardiovascular Division, Washington University, St Louis, MO 63110, USA.
Insights
Myocardial anisotropy affects ultrasonic tissue characterization. Echocardiographic view and left ventricular segment significantly influence cyclic variation analysis, impacting diagnostic accuracy.
Area of Science:
- Cardiovascular Imaging
- Biomedical Ultrasound
- Myocardial Mechanics
Background:
- Myocardial anisotropy, the directional dependence of tissue properties, is crucial for accurate ultrasonic tissue characterization.
- Cyclic variation of myocardial integrated backscatter (CVMIB) is a promising ultrasound technique for assessing myocardial tissue properties.
Purpose of the Study:
- To investigate the influence of myocardial anisotropy on CVMIB measurements.
- To determine how different echocardiographic views and left ventricular segments affect CVMIB time delay values.
Main Methods:
- Analyzed 2D integrated backscatter images from 23 healthy subjects.
- Measured CVMIB time delay in 10 myocardial regions across 4 standard transthoracic echocardiographic views (parasternal long-axis, short-axis, apical 4-chamber, apical 2-chamber).
Main Results:
- Significant variations in CVMIB time delay were observed across different echocardiographic views and myocardial segments.
- For instance, lateral wall measurements in parasternal short-axis and apical 4-chamber views showed higher time delays (2.22 +/- 0.71 and 2.20 +/- 0.79, respectively) compared to septum or posterior wall measurements.
Conclusions:
- Myocardial ultrasonic characterization using CVMIB is significantly influenced by the chosen echocardiographic view.
- The specific segment of the left ventricle analyzed also impacts CVMIB measurements, highlighting the importance of considering anisotropy in ultrasound diagnostics.
Abstract:
To determine the influence of myocardial anisotropy in ultrasonic tissue characterization, we measured the time delay (and magnitude) of the cyclic variation of myocardial integrated backscatter from specific segments visualized in the 4 standard transthoracic echocardiographic views. The cyclic variation data in 10 myocardial regions were obtained from analyses of 2-dimensional integrated backscatter images from 23 healthy subjects. Resultant values (mean +/- SD) for the time delay were as follows: parasternal long-axis view: 1.08 +/- 0.17 (septum) and 1.00 +/- 0.14 (posterior wall); parasternal short-axis view: 1.03 +/- 0.16 (anterior septum), 1.03 +/- 0.14 (posterior wall), 2.22 +/- 0.71 (lateral wall), and 1.65 +/- 0.66 (posterior septum); apical 4-chamber view: 1.08 +/- 0.31 (septum) and 2.20 +/- 0.79 (lateral wall); and apical 2-chamber view: 1.68 +/- 0.62 (inferior wall) and 2.04 +/- 0.72 (anterior wall). Hence, results of this study indicate that myocardial ultrasonic characterization that uses the cyclic variation is influenced by the echocardiographic view and the specific segment of the left ventricle.
