Evaluation of the image quality and validity of handheld echocardiography for stroke volume and left ventricular ejection fraction quantification:a method comparison study

Bedside quantification of stroke volume (SV) and left ventricular ejection fraction (LVEF) is valuable in hemodynamically compromised patients. Miniaturized handheld ultrasound (HAND) devices are now available for clinical use. However, the performance level of HAND devices for quantified cardiac assessment is yet unknown. The aim of this study was to compare the validity of HAND measurements with standard echocardiography (SE) and three-dimensional echocardiography (3DE). Thirty-six patients were scanned with HAND, SE and 3DE. LVEF and SV quantification was done with automated software for the HAND, SE and 3DE dataset. The image quality of HAND and SE was evaluated by scoring segmental endocardial border delineation (2 = good, 1 = poor, 0 = invisible). LVEF and SV of HAND was evaluated against SE and 3DE using correlation and Bland-Altman analysis. The correlation, bias, and limits of agreement (LOA) between HAND and SE were 0.68 [0.46:0.83], 1.60% [- 2.18:5.38], and 8.84% [- 9.79:12.99] for LVEF, and 0.91 [0.84:0.96], 1.32 ml [- 0.36:4.01], 15.54 ml [- 18.70:21.35] for SV, respectively. Correlation, bias, and LOA between HAND and 3DE were 0.55 [0.6:0.74], - 0.56% [- 2.27:1.1], and 9.88% [- 13.29:12.17] for LVEF, and 0.79 [0.62:0.89], 6.78 ml [2.34:11.21], 12.14 ml [- 26.32:39.87] for SV, respectively. The image quality scores were 9.42 ± 2.0 for the apical four chamber views of the HAND dataset and 10.49 ± 1.7 for the SE dataset and (P &lt; 0.001). Clinically acceptable accuracy, precision, and image quality was demonstrated for HAND measurements compared to SE. In comparison to 3DE, HAND showed a clinically acceptable accuracy and precision for LVEF quantification.</p

Evaluation of the image quality and validity of handheld echocardiography for stroke volume and left ventricular ejection fraction quantification:a method comparison study

Bedside quantification of stroke volume (SV) and left ventricular ejection fraction (LVEF) is valuable in hemodynamically compromised patients. Miniaturized handheld ultrasound (HAND) devices are now available for clinical use. However, the performance level of HAND devices for quantified cardiac assessment is yet unknown. The aim of this study was to compare the validity of HAND measurements with standard echocardiography (SE) and three-dimensional echocardiography (3DE). Thirty-six patients were scanned with HAND, SE and 3DE. LVEF and SV quantification was done with automated software for the HAND, SE and 3DE dataset. The image quality of HAND and SE was evaluated by scoring segmental endocardial border delineation (2 = good, 1 = poor, 0 = invisible). LVEF and SV of HAND was evaluated against SE and 3DE using correlation and Bland-Altman analysis. The correlation, bias, and limits of agreement (LOA) between HAND and SE were 0.68 [0.46:0.83], 1.60% [- 2.18:5.38], and 8.84% [- 9.79:12.99] for LVEF, and 0.91 [0.84:0.96], 1.32 ml [- 0.36:4.01], 15.54 ml [- 18.70:21.35] for SV, respectively. Correlation, bias, and LOA between HAND and 3DE were 0.55 [0.6:0.74], - 0.56% [- 2.27:1.1], and 9.88% [- 13.29:12.17] for LVEF, and 0.79 [0.62:0.89], 6.78 ml [2.34:11.21], 12.14 ml [- 26.32:39.87] for SV, respectively. The image quality scores were 9.42 ± 2.0 for the apical four chamber views of the HAND dataset and 10.49 ± 1.7 for the SE dataset and (P &lt; 0.001). Clinically acceptable accuracy, precision, and image quality was demonstrated for HAND measurements compared to SE. In comparison to 3DE, HAND showed a clinically acceptable accuracy and precision for LVEF quantification.</p

A Spatial Near-Field Clutter Reduction Filter Preserving Tissue Speckle in Echocardiography

Near-field (NF) clutter in echocardiography is depicted as a diffuse haze hindering the visualization of the myocardium and the blood-pool, thereby degrading its diagnostic value. Several clutter filters have been developed, which are limited in patients with contraction motion and rhythm anomalies, and in 3-D ultrasound (US). This study introduces a new NF clutter reduction method, which preserves US speckles required for strain imaging. The filter developed detects the NF clutter region in the spatial frequency domain. The filter employs an oriented, multiscale approach, and assumes the NF clutter to be predominantly present in the highest and lowest bandpass images. These bandpass images were filtered, whilst sparing features in the myocardium and NF clutter-free regions. The performance of the filter was assessed in a volunteer study, in ten 3-D apical and parasternal view acquisitions, and in a retrospective clinical study composed of 20 cardiac patients with different indications for echocardiography. The filter reduced NF clutter in all data sets, whilst preserving all or most of the myocardium. Additionally, it demonstrated a consistent enhancement of image quality, with an increase in contrast of 4.3 dB on average, and generated a clearer myocardial boundary distinction. Furthermore, the speckles were preserved according to the quality index based on local variance, the structural similarity index method, and normalized cross correlation values, being 0.82, 0.92, and 0.95 on average, respectively. Global longitudinal strain measurements on NF clutter reduced images were improved or equivalent compared to the original acquisitions, with an average increase in strain signal-to-noise ratio of 34%

Auto-combustion synthesis of perovskite-type oxides SrTi1−xFexO3−δ

A versatile one-pot auto-combustion method for the synthesis of powders of iron-doped strontium titanate, SrTi1−xFexO3−δ, has been developed. The synthesis is optimized by the combined use of EDTA and citric acid as chelating agents, and an appropriate balance between fuel and oxidizing elements in the reaction mixture. The method produces immediately an almost phase-pure perovskite oxide powder, with an ultra-fine crystallite size of 20–40 nm, and with a low level of organic residues. Highly sinter-active powders are obtained after calcination and ball-milling of the powders

High microvascular resistance and reduced left atrial strain in patients with coronary microvascular dysfunction: The micro-strain study

BACKGROUND: It is already known that high coronary microvascular resistance (Rμ) is linked to altered left ventricular stiffness and might be an early indicator of heart failure with preserved ejection fraction (HFpEF). Left atrial dysfunction, on the other hand, varies according to the grade of left ventricular diastolic dysfunction. This is the first study to use the latest development for invasive assessment of Rμ and to combine it with echocardiographic assessment of left atrial strain during reservoir phase (LASr) by speckle tracking in relation to left ventricular (LV) diastolic function. METHODS AND RESULTS: An invasive angiogram was performed in 97 patients because of suspected ANOCA. All patients underwent comprehensive echocardiography, yet image quality was poor in 15 patients leaving 82 patients to include in the final analysis. In order to compare Rμ with LASr values, patients were divided into 4 groups based upon normal values of Rμ as defined by Fournier et al. The mean LASr was plotted against the four resistance groups. The LASr was 48.6% in the lowest resistance group, and 40.1%, 36.3% and 30.1% in the low intermediate, high intermediate and high resistance group respectively. These differences were significant compared to the lowest resistance group (p < 0.05). Although higher Rμ groups showed more diastolic dysfunction, LASr was already decreased irrespective of the severity of diastolic dysfunction. CONCLUSION: This study shows a relationship between increased Rμ and reduced LASr, that seems to precede conventional measures of left ventricular diastolic dysfunction. This suggests that microvascular dysfunction might be an early indicator for the development of impaired LA function