Effect of angular error on tissue Doppler velocities and strain.

Area of Science:

• Cardiovascular Imaging
• Echocardiography
• Medical Ultrasound

Background:

• Ultrasound Doppler's angle dependency limits velocity measurements to components along the transducer's line of sight.
• This angular error is a significant concern in clinical applications of Doppler echocardiography.

Purpose of the Study:

• To evaluate the clinical impact of angular error on myocardial velocity measurements.
• To assess the effect of correcting for angle dependency on longitudinal strain calculations.

Main Methods:

• Apical two- and four-chamber views were acquired from 43 individuals.
• Myocardial velocities were measured, and angular error was corrected by back-projection onto the longitudinal axis.
• Myocardial strain was calculated from both corrected and uncorrected velocities in 12 myocardial segments per individual.

Main Results:

• The difference between corrected and uncorrected strain values was insignificant in 5 segments and minor (decimal range) in 11 segments.
• The largest discrepancies between measured and corrected strain were observed in apical segments.
• Strain calculations demonstrated greater robustness against angular error compared to velocity measurements.

Conclusions:

• Angular error has minimal impact on longitudinal strain calculations in clinical echocardiography.
• Correction for angular error in ultrasound Doppler measurements of longitudinal strain can be safely omitted.