A comparison between unfocused and focused transmit strategies in cardiac strain imaging

• Published in: Physics in medicine & biology Vol. 65; no. 3; pp. 3 - 03NT01
• Main Authors: Sayseng, Vincent, Grondin, Julien, Weber, Rachel A, Konofagou, Elisa
• Format: Journal Article
• Language: English
• Published: England IOP Publishing 24.01.2020
• Subjects: Adult; Cardiac Imaging Techniques - methods; cardiac strain imaging; coherent compounding; Heart - diagnostic imaging; Heart - physiology; Heart Ventricles - diagnostic imaging; Heart Ventricles - physiopathology; high frame-rate imaging; Humans; Image Processing, Computer-Assisted - methods; Male; Models, Theoretical; transthoracic imaging; Ultrasonography - methods; ultrasound simulation
• ISSN: 0031-9155; 1361-6560; 1361-6560
• DOI: 10.1088/1361-6560/ab4afd

Unfocused ultrasound imaging, particularly coherent compounding with diverging waves, is a commonly employed high-frame rate transmit strategy in cardiac strain imaging. However, the accuracy and precision of diverging wave imaging compared to focused-beam transmit approaches in human subjects is unknown. Three transmit strategies-coherent compounding imaging, composite focused imaging with ECG gating and narrow-beams, and focused imaging with wide-beams-were compared in simulation and in transthoracic imaging of healthy human subjects (n  =  7). The focused narrow-beam sequence estimated radial end-systolic cumulative strains of a simulated left ventricular deformation with 26%  ±  1.5% and 34%  ±  1.5% greater accuracy compared with compounding and wide-beam imaging, respectively. Strain estimation precision in transthoracic imaging was then assessed with the Strain Filter on cumulative end-systolic radial strains. Within the strain values where statistically significant differences in precision (E(SNRe| )) were found between transmit strategies, the narrow-beam sequence estimated radial strain 13%  ±  0.71% and 34%  ±  8.9% more precisely on average compared to compounding or wide-beam imaging, respectively.