Strain rate imaging using two-dimensional speckle tracking

Kałużyński, K.; Chen, Xunchang; Emelianov, Stanislav; Skovoroda, A.R.; O’Donnell, Matthew

doi:10.1109/58.935730

Cited by 196 publications

(144 citation statements)

References 25 publications

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“…The automated software then calculated the rotation and rotational velocities of the region of interest. 22,23 The motion of the apex and base are conventionally described from an apex-to-base view down the longitudinal axis of the LV, with clockwise rotations measured in negative degrees and counterclockwise rotations measured in positive degrees (Figure 1). Left ventricular torsion is the sum of maximal instantaneous basal-to-apex angle difference, expressed in degrees.…”

Section: Echocardiography Protocolmentioning

confidence: 99%

Left Ventricular Torsional Mechanics in Uncomplicated Pregnancy

Yoon

Song²,

Megalla³

et al. 2011

Clinical Cardiology

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Background: Alterations in left ventricular (LV) twist (torsion) and untwist have been described for a variety of physiologic and pathologic conditions. Little information is available regarding changes in these parameters during normal pregnancy. Hypothesis: Pregnancy is associated with significant changes in LV torsional mechanics. Methods: Left ventricular twist and untwist was measured in 32 pregnant females (mean gestation 199 ± 48 d) and 23 nonpregnant controls using speckle-tracking echocardiography.Results: Left ventricular ejection fraction (68 ± 5% vs 66 ± 5%) was similar between the groups (P not significant). There was a significant increase in peak LV twist from nonpregnant controls (9.4 ± 3.7 degrees) to second-trimester (12.0 ± 4.2 degrees) and third-trimester subjects (12.6 ± 5.9 degrees, all P < 0.05). Peak LV twist velocity was also increased in second-and third-trimester groups compared with controls (94 ± 24 degrees/sec and 93 ± 30 vs 64 ± 21 degrees/sec, respectively, both P < 0.05). Both peak untwist velocity and time to peak untwist velocity were not significantly different between groups (P not significant). Multiple regression analysis indicate that only systolic blood pressure (r = 0.394, P = 0.005) was an independent predictor for increased LV torsion. Conclusions: There are significant changes in LV torsional indices during the course of pregnancy, whereas untwist parameters remain unchanged. Blood pressure is independently associated with increased torsion during pregnancy. IntroductionPregnancy is associated with reversible adaptations in maternal systolic and diastolic left ventricular (LV) function. 1,2 Prior studies have shown increased preload and cardiac output, 3 -5 decreased systemic vascular resistance, 2,6 and increased LV mass and wall thickness 7 during pregnancy. Changes in LV fractional shortening are less well-defined, with the literature offering conflicting data. 8 -10 Little information is available concerning alterations in LV torsion (LV Tor ), the helical twisting motion of the LV about its longitudinal long axis. 11 Speckle-tracking echocardiography (STE) is a noninvasive method that allows for rapid, objective quantification of LV Tor . 12 Numerous studies have demonstrated that STE can accurately quantify differences in LV Tor associated with various pathophysiologic conditions. 13 -16 We used STE to measure LV Tor in healthy pregnant women and nonpregnant controls.

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Section: Echocardiography Protocolmentioning

confidence: 99%

Left Ventricular Torsional Mechanics in Uncomplicated Pregnancy

Yoon

Song²,

Megalla³

et al. 2011

Clinical Cardiology

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“…12,13 Estimated displacements were accumulated in 0.3% to 0.6% compression steps. 14 The gradient of the axial displacements was used to calculate strain.…”

Section: Derivation Of the Correlation Coefficient From 2-dimensionalmentioning

confidence: 99%

Diagnosing Cysts With Correlation Coefficient Images From 2-Dimensional Freehand Elastography

Booi

Carson

O’Donnell

et al. 2007

Journal of Ultrasound in Medicine

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Objective. We compared the diagnostic potential of using correlation coefficient images versus elastograms from 2-dimensional (2D) freehand elastography to characterize breast cysts. Methods. In this preliminary study, which was approved by the Institutional Review Board and compliant with the Health Insurance Portability and Accountability Act, we imaged 4 consecutive human subjects (4 cysts, 1 biopsy-verified benign breast parenchyma) with freehand 2D elastography. Data were processed offline with conventional 2D phase-sensitive speckle-tracking algorithms. The correlation coefficient in the cyst and surrounding tissue was calculated, and appearances of the cysts in the correlation coefficient images and elastograms were compared. Results. The correlation coefficient in the cysts was considerably lower (14%-37%) than in the surrounding tissue because of the lack of sufficient speckle in the cysts, as well as the prominence of random noise, reverberations, and clutter, which decorrelated quickly. Thus, the cysts were visible in all correlation coefficient images. In contrast, the elastograms associated with these cysts each had different elastographic patterns. The solid mass in this study did not have the same high decorrelation rate as the cysts, having a correlation coefficient only 2.1% lower than that of surrounding tissue. Conclusions. Correlation coefficient images may produce a more direct, reliable, and consistent method for characterizing cysts than elastograms.

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“…The myocardium is frequently considered as an incompressible body and the myocardial motion consists of the displacements due to deformation and translation (9) . Therefore, the scatterers' positions are relocated according to the postdeformation results.…”

Section: Simulation Conditionsmentioning

confidence: 99%

“…Therefore, the average twisting between two adjacent frames is about 1 degree (0.0174 rad) when the frame rate is 30 frame-per-seconds (FPS), and the radial strain in normal wall is about 2%. The stiffness of the infarction is set to be about two times greater than that of the surrounding normal wall, because this stiffness ratio is generally referred to as the typical stiffness ratio of the infarction to normal wall (9) . To realize the stiffness in the infarcted region is three times that in the normal region, the radial strain ε rr in the infarcted region is set to be one third of that in the normal region.…”

Section: Simulation Conditionsmentioning

confidence: 99%