Echo speckle imaging of blood particles with high-frame-rate echocardiography

Abstract

Cardiac blood flow patterns such as the vortex flow pattern inside the left ventricle have been studied to provide new information for the diagnosis of the pumping function of the human heart. Complex blood flow is visualized by imaging echo speckles of blood particles because the speckle-like texture translates to the motion of blood particles. We proposed an imaging method for echo speckles of blood particles using high-frame-rate ultrasound for the visualization of the intracardiac blood flow direction. High-frame-rate ultrasound is useful for continuously observing the fast motion of echoes from blood particles in the heart. In the present study, weighting by coherence and compounding the magnitudes of echo signals in different transmissions were introduced to visualize weak echoes from blood particles. The feasibility of the visualization of cardiac blood flow using high-frame-rate ultrasound was demonstrated by basic and in vivo experiments.

Phase-Sensitive 2D Motion Estimators Using Frequency Spectra of Ultrasonic Echoes

“…axial window size (mm) (K) lateral window size (mm) (M) ±0.5 (5) ±1.0 (10) ±1.5 (15) ±2.0 (20) ±2.5 (25) ±0.1232 ( Table 9. Bias errors e bias and standard deviations σ of lateral and axial displacements at the same points shown in Figure 4a estimated by the conventional 2D motion estimator with frame averaging.…”

“…axial window size (mm) (K) lateral window size (mm) (M) ±0.5 (5) ±1.0 (10) ±1.5 (15) ±2.0 (20) ±2.5 (25) ±0.1232 ( ±0.5 (5) ±1.0 (10) ±1.5 (15) ±2.0 (20) ±2.5 (25) ±0.1232 (5) -0.02 ± 0.10 -0.01 ± 0.10 -0.01 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 ±0.2464 (10) 0.00 ± 0.10 -0.01 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 ±0.3696 (15) 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 ±0.4928 (20) 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 0.00 ± 0.10 Table 10. Bias errors e bias and standard deviations σ of lateral and axial displacements at the same points shown in Figure 4a estimated by the proposed 2D motion estimator with frame averaging.…”

“…axial window size (mm) (K) lateral window size (mm) (M) ±0.5 (5) ±1.0 (10) ±1.5 (15) ±2.0 (20) ±2.5 (25) ±0.1232 ( …”

“…After the development of shear wave elastography by Tanter, et al [11], which was the first practical application of high-frame-rate ultrasound, various studies have been conducted for cardiovascular applications, such as vascular strain and blood flow imaging [12][13][14], pulse wave imaging [15,16], and cardiac strain and blood flow imaging [17][18][19][20][21]. In addition, various studies for improvement of the image quality in high-frame-rate ultrasound have been conducted [22][23][24][25][26].…”

Iterative 2D Tissue Motion Tracking in Ultrafast Ultrasound Imaging

“…Ultrafast ultrasound imaging has been used as the basis for the development of a number of methods intended for diagnosing and exploring different phenomena in vivo, e.g., shear wave elastography [1][2][3][4], acoustic radiation force impulse imaging [5], vector flow imaging [6][7][8], and a method for skeletal muscle contraction [9], functional ultrasound imaging of the brain [10], and cardiac motion [11,12]. The arterial walls have been investigated by estimating the radial strain in the common carotid artery [13] and the radial pulse wave velocity [14,15].…”