The Experts below are selected from a list of 150 Experts worldwide ranked by ideXlab platform

Muhammad Ashraf - One of the best experts on this subject based on the ideXlab platform.

  • non invasive evaluation of heart function with Four Dimensional Echocardiography
    PLOS ONE, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P <0.001). Bland-Altman analyses showed slight overestimations of echo-derived GLS, GCS, 2DE-LVEF and 3DE-LVEF over sonomicrometry values (bias = 2.88, bias = 3.99, bias = 3.37, bias = 2.78, respectively). Furthermore, there is better agreement between GCS, 4D LVEF and sonomicrometry values compared with GLS and 2D LVEF. Conclusion Four-Dimensional Echocardiography accurately assesses LV function. GCS derived by 4DE is a potential alternative parameter to quantify LV systolic function.

  • Non-Invasive Evaluation of Heart Function with Four-Dimensional Echocardiography
    PloS one, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P

  • IMAGE BASED EVALUATION OF RIGHT VENTRICULAR MYOCARDIAL STRAIN MECHANICS USING 4D AND 2D Echocardiography
    Journal of the American College of Cardiology, 2016
    Co-Authors: David J Sahn, Meihua Zhu, Alexandra Pidwerbecki, Karla Fuentes, Kacie Amacher, Joanne Tran, Kim Dang, Evan Tracy, Ramya Ajjarapu, Muhammad Ashraf
    Abstract:

    We tested the feasibility of Four-Dimensional Echocardiography (4DE) for evaluation of RV mechanics. Eight freshly harvested porcine RV models were studied. Latex balloons were sewn into the mitral annulus and connected to a pump to create a pulsatile motion in the RV. Eight sonomicrometry crystals

  • Abstract 13613: 4D Echo-Derived Global Area Strain is a Better Mechanical Index of RV Function
    Circulation, 2015
    Co-Authors: Kacie Amacher, Meihua Zhu, Muhammad Ashraf, David J Sahn
    Abstract:

    Introduction: There is increasing interest in image based evaluation of RV mechanics. Hypothesis: Four-Dimensional Echocardiography (4DE) accurately assesses RV function, compared against sonomicrometry. Methods: Six porcine RV models were studied. Each RV was connected to a pump apparatus to generate pulsatile motion. Six sonomicrometry (sono) crystals were sutured in a triangle formation onto the RV to acquire volume. Right ventricular ejection fraction (RVEF), 3D global area strain (GAS), global circumferential strain (GCS), global longitudinal strain (GLS), and global radial strain (GRS) were obtained by 4D Echocardiography at stroke volumes of 30-70 ml. Results were correlated with RVEF determined by sonomicrometry analysis. Results: Linear regression of all EchoPAC-derived parameters, RVEF, GAS, GCS, GLS, and GRS showed strong correlations with RVEF from sono data (r = 0.73, r = 0.78, r = 0.72, r = 0.75, r = 0.75, respectively; all P Conclusions: 4DE demonstrates the ability to accurately and feasibly assess RV function, and GAS showed the highest correlation with the reference ejection fraction.

  • evaluation of stroke volume and ventricular mass in a fetal heart model a novel Four Dimensional echocardiographic analysis
    Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques, 2014
    Co-Authors: Meihua Zhu, Muhammad Ashraf, B A Jill Panosian, David N. Roundhill, Michael Lapin, M Cole D Streiff, M Boris D Tutschek, J David M D Sahn
    Abstract:

    Aims This study aimed to assess the feasibility and accuracy of nongated Four-Dimensional Echocardiography (4DE) for determining left ventricular (LV) stroke volume (SV) and mass in a fetal heart-sized LV model. Methods A balloon was inserted into the LV of 20 fresh rabbit hearts and attached to a calibrated pulsatile pump. Ten hearts retaining the right ventricle were imaged in Group A. Ten hearts without the right ventricles (RVs) attached were imaged in Group B. Nongated 4D volumes were obtained using a Philips iU-22 system with an X6-1 matrix probe at SVs ranging from 1 to 5 mL at increments of 1 mL. At each SV, the volume displacement of the heart was measured at end-systole and end-diastole. Mass was determined by displacement at the conclusion of the experiment. Results The images were analyzed offline by manually tracing endocardial and epicardial boundaries of stacked contours. An excellent correlation in SV and mass between echo-derived values and displacement values was demonstrated and accompanied by high coefficients of determination (R2) in both groups (SV: Group A: R2 = 0.9461, Group B: R2 = 0.9811; Mass: Group A: R2 = 0.9223, Group B: R2 = 0.9602; all P < 0.001). Bland–Altman analyses showed a slight overestimation in both groups for both SV and LV mass. Conclusions Nongated 4DE was demonstrated to be feasible and that it could accurately define SV and ventricular mass for a fetal heart-sized LV model.

Ying Zhang - One of the best experts on this subject based on the ideXlab platform.

David J Sahn - One of the best experts on this subject based on the ideXlab platform.

  • non invasive evaluation of heart function with Four Dimensional Echocardiography
    PLOS ONE, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P <0.001). Bland-Altman analyses showed slight overestimations of echo-derived GLS, GCS, 2DE-LVEF and 3DE-LVEF over sonomicrometry values (bias = 2.88, bias = 3.99, bias = 3.37, bias = 2.78, respectively). Furthermore, there is better agreement between GCS, 4D LVEF and sonomicrometry values compared with GLS and 2D LVEF. Conclusion Four-Dimensional Echocardiography accurately assesses LV function. GCS derived by 4DE is a potential alternative parameter to quantify LV systolic function.

  • Non-Invasive Evaluation of Heart Function with Four-Dimensional Echocardiography
    PloS one, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P

  • IMAGE BASED EVALUATION OF RIGHT VENTRICULAR MYOCARDIAL STRAIN MECHANICS USING 4D AND 2D Echocardiography
    Journal of the American College of Cardiology, 2016
    Co-Authors: David J Sahn, Meihua Zhu, Alexandra Pidwerbecki, Karla Fuentes, Kacie Amacher, Joanne Tran, Kim Dang, Evan Tracy, Ramya Ajjarapu, Muhammad Ashraf
    Abstract:

    We tested the feasibility of Four-Dimensional Echocardiography (4DE) for evaluation of RV mechanics. Eight freshly harvested porcine RV models were studied. Latex balloons were sewn into the mitral annulus and connected to a pump to create a pulsatile motion in the RV. Eight sonomicrometry crystals

  • Abstract 13613: 4D Echo-Derived Global Area Strain is a Better Mechanical Index of RV Function
    Circulation, 2015
    Co-Authors: Kacie Amacher, Meihua Zhu, Muhammad Ashraf, David J Sahn
    Abstract:

    Introduction: There is increasing interest in image based evaluation of RV mechanics. Hypothesis: Four-Dimensional Echocardiography (4DE) accurately assesses RV function, compared against sonomicrometry. Methods: Six porcine RV models were studied. Each RV was connected to a pump apparatus to generate pulsatile motion. Six sonomicrometry (sono) crystals were sutured in a triangle formation onto the RV to acquire volume. Right ventricular ejection fraction (RVEF), 3D global area strain (GAS), global circumferential strain (GCS), global longitudinal strain (GLS), and global radial strain (GRS) were obtained by 4D Echocardiography at stroke volumes of 30-70 ml. Results were correlated with RVEF determined by sonomicrometry analysis. Results: Linear regression of all EchoPAC-derived parameters, RVEF, GAS, GCS, GLS, and GRS showed strong correlations with RVEF from sono data (r = 0.73, r = 0.78, r = 0.72, r = 0.75, r = 0.75, respectively; all P Conclusions: 4DE demonstrates the ability to accurately and feasibly assess RV function, and GAS showed the highest correlation with the reference ejection fraction.

  • Evaluation of stroke volume and ventricular mass in a fetal heart model: a novel Four-Dimensional echocardiographic analysis.
    Echocardiography (Mount Kisco N.Y.), 2014
    Co-Authors: Meihua Zhu, Muhammad Ashraf, Cole Streiff, B A Jill Panosian, David N. Roundhill, Michael Lapin, Boris Tutschek, David J Sahn
    Abstract:

    Aims This study aimed to assess the feasibility and accuracy of nongated Four-Dimensional Echocardiography (4DE) for determining left ventricular (LV) stroke volume (SV) and mass in a fetal heart-sized LV model. Methods A balloon was inserted into the LV of 20 fresh rabbit hearts and attached to a calibrated pulsatile pump. Ten hearts retaining the right ventricle were imaged in Group A. Ten hearts without the right ventricles (RVs) attached were imaged in Group B. Nongated 4D volumes were obtained using a Philips iU-22 system with an X6-1 matrix probe at SVs ranging from 1 to 5 mL at increments of 1 mL. At each SV, the volume displacement of the heart was measured at end-systole and end-diastole. Mass was determined by displacement at the conclusion of the experiment. Results The images were analyzed offline by manually tracing endocardial and epicardial boundaries of stacked contours. An excellent correlation in SV and mass between echo-derived values and displacement values was demonstrated and accompanied by high coefficients of determination (R2) in both groups (SV: Group A: R2 = 0.9461, Group B: R2 = 0.9811; Mass: Group A: R2 = 0.9223, Group B: R2 = 0.9602; all P 

Meihua Zhu - One of the best experts on this subject based on the ideXlab platform.

  • non invasive evaluation of heart function with Four Dimensional Echocardiography
    PLOS ONE, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P <0.001). Bland-Altman analyses showed slight overestimations of echo-derived GLS, GCS, 2DE-LVEF and 3DE-LVEF over sonomicrometry values (bias = 2.88, bias = 3.99, bias = 3.37, bias = 2.78, respectively). Furthermore, there is better agreement between GCS, 4D LVEF and sonomicrometry values compared with GLS and 2D LVEF. Conclusion Four-Dimensional Echocardiography accurately assesses LV function. GCS derived by 4DE is a potential alternative parameter to quantify LV systolic function.

  • Non-Invasive Evaluation of Heart Function with Four-Dimensional Echocardiography
    PloS one, 2016
    Co-Authors: Ran Chen, Meihua Zhu, David J Sahn, Muhammad Ashraf
    Abstract:

    Background The aim of this study is to assess the accuracy and feasibility of left ventricular systolic function determined by Four-Dimensional Echocardiography (4DE). Methods Latex balloons were sewn into the left ventricle (LV) of 20 freshly harvested pig hearts which were then passively driven by a pulsatile pump apparatus. Global longitudinal strain (GLS), global circumferential strain (GCS), global area strain (GAS) and left ventricular ejection fraction (LVEF) derived from 4DEand two-Dimensional Echocardiography (2DE)-derived LVEF were quantified at different stroke volumes (SV) 30–70 ml and correlated with sonomicrometry data. Results In all comparisons, GLS, GCS, GAS, 2DE-LVEF, and 4DE-LVEF demonstrated strong correlations with sonomicrometry data (r = 0.77, r = 0.89, r = 0.79, r = 0.93, r = 0.96, all P

  • IMAGE BASED EVALUATION OF RIGHT VENTRICULAR MYOCARDIAL STRAIN MECHANICS USING 4D AND 2D Echocardiography
    Journal of the American College of Cardiology, 2016
    Co-Authors: David J Sahn, Meihua Zhu, Alexandra Pidwerbecki, Karla Fuentes, Kacie Amacher, Joanne Tran, Kim Dang, Evan Tracy, Ramya Ajjarapu, Muhammad Ashraf
    Abstract:

    We tested the feasibility of Four-Dimensional Echocardiography (4DE) for evaluation of RV mechanics. Eight freshly harvested porcine RV models were studied. Latex balloons were sewn into the mitral annulus and connected to a pump to create a pulsatile motion in the RV. Eight sonomicrometry crystals

  • Abstract 13613: 4D Echo-Derived Global Area Strain is a Better Mechanical Index of RV Function
    Circulation, 2015
    Co-Authors: Kacie Amacher, Meihua Zhu, Muhammad Ashraf, David J Sahn
    Abstract:

    Introduction: There is increasing interest in image based evaluation of RV mechanics. Hypothesis: Four-Dimensional Echocardiography (4DE) accurately assesses RV function, compared against sonomicrometry. Methods: Six porcine RV models were studied. Each RV was connected to a pump apparatus to generate pulsatile motion. Six sonomicrometry (sono) crystals were sutured in a triangle formation onto the RV to acquire volume. Right ventricular ejection fraction (RVEF), 3D global area strain (GAS), global circumferential strain (GCS), global longitudinal strain (GLS), and global radial strain (GRS) were obtained by 4D Echocardiography at stroke volumes of 30-70 ml. Results were correlated with RVEF determined by sonomicrometry analysis. Results: Linear regression of all EchoPAC-derived parameters, RVEF, GAS, GCS, GLS, and GRS showed strong correlations with RVEF from sono data (r = 0.73, r = 0.78, r = 0.72, r = 0.75, r = 0.75, respectively; all P Conclusions: 4DE demonstrates the ability to accurately and feasibly assess RV function, and GAS showed the highest correlation with the reference ejection fraction.

  • evaluation of stroke volume and ventricular mass in a fetal heart model a novel Four Dimensional echocardiographic analysis
    Echocardiography-a Journal of Cardiovascular Ultrasound and Allied Techniques, 2014
    Co-Authors: Meihua Zhu, Muhammad Ashraf, B A Jill Panosian, David N. Roundhill, Michael Lapin, M Cole D Streiff, M Boris D Tutschek, J David M D Sahn
    Abstract:

    Aims This study aimed to assess the feasibility and accuracy of nongated Four-Dimensional Echocardiography (4DE) for determining left ventricular (LV) stroke volume (SV) and mass in a fetal heart-sized LV model. Methods A balloon was inserted into the LV of 20 fresh rabbit hearts and attached to a calibrated pulsatile pump. Ten hearts retaining the right ventricle were imaged in Group A. Ten hearts without the right ventricles (RVs) attached were imaged in Group B. Nongated 4D volumes were obtained using a Philips iU-22 system with an X6-1 matrix probe at SVs ranging from 1 to 5 mL at increments of 1 mL. At each SV, the volume displacement of the heart was measured at end-systole and end-diastole. Mass was determined by displacement at the conclusion of the experiment. Results The images were analyzed offline by manually tracing endocardial and epicardial boundaries of stacked contours. An excellent correlation in SV and mass between echo-derived values and displacement values was demonstrated and accompanied by high coefficients of determination (R2) in both groups (SV: Group A: R2 = 0.9461, Group B: R2 = 0.9811; Mass: Group A: R2 = 0.9223, Group B: R2 = 0.9602; all P < 0.001). Bland–Altman analyses showed a slight overestimation in both groups for both SV and LV mass. Conclusions Nongated 4DE was demonstrated to be feasible and that it could accurately define SV and ventricular mass for a fetal heart-sized LV model.

Ailu Cai - One of the best experts on this subject based on the ideXlab platform.

  • Four-Dimensional Echocardiography with spatiotemporal image correlation and inversion mode for detection of congenital heart disease.
    Ultrasound in medicine & biology, 2014
    Co-Authors: Yue Qin, Ying Zhang, Yu Wang, Wei Sun, Xiaohang Zhou, Lizhu Chen, Dan Zhao, Ying Zhan, Ailu Cai
    Abstract:

    The aim of this study was to evaluate the use of 4-D Echocardiography with inversion mode and spatiotemporal image correlation (IM-STIC) in the detection of normal and abnormal fetal hearts. We retrospectively studied 112 normal fetuses and 16 fetuses with a confirmed diagnosis of congenital heart disease. Two volumes were acquired from each of the fetuses using transverse and sagittal sweeps. Volumes were reconstructed with IM-STIC. In normal fetuses, IM-STIC facilitated visualization of the interior structures of the fetal heart and great vessels. The visualization rates of intended planes obtained from IM-STIC 4D data ranged from 55% to 100%. In 16 fetuses with congenital heart disease, IM-STIC was able to display the cardiac malformations using digital casting. Some of the malformations were suspected during pre-natal 2-D Echocardiography, and their pre-natal IM-STIC diagnoses were confirmed by post-natal Echocardiography, surgery and/or autopsy. Hence, 4-D IM-STIC allows better visualization of complex congenital heart disease and should be considered a very useful addition to 2-D Echocardiography.

  • Evaluation of normal fetal pulmonary veins using B‐flow imaging with spatiotemporal image correlation and by traditional color Doppler Echocardiography
    Prenatal diagnosis, 2012
    Co-Authors: Ying Zhang, Changwei Ding, Miao Fan, Wei Sun, Wei-dong Ren, Ya-jun Guo, Ailu Cai
    Abstract:

    Objective The purpose of our report is to evaluate the use of color Doppler Echocardiography (CDE) with Four chamber view (4CV), scanning around left atrium, and Four-Dimensional Echocardiography with B-flow imaging and spatiotemporal image correlation (4D BF-STIC) in detecting fetal pulmonary veins at 17 to 40 weeks’ gestation. Methods This was a prospective study. Color Doppler Echocardiography with 4CV, scanning around left atrium, and 4D BF-STIC were used to detect the pulmonary veins in 460 normal fetuses at 17 to 40 weeks of gestation. Routine prenatal screening was used to confirm that the fetuses were in good health with no cardiac or extra cardiac anomalies. All patients underwent follow up at one year. Twenty-two patients were excluded from the study. The number of pulmonary veins visualized using each method was recorded and then compared in six subgroups according to gestational age. Results Four-Dimensional Echocardiography with B-flow imaging and spatiotemporal image correlation was the best method to detect the greatest number of pulmonary veins between 17 and 31 weeks of gestation. Scanning around left atrium detected more pulmonary veins than the traditional 4CV method throughout the gestational period. Conclusions The scanning around left atrium method proved to be the most suited for detecting pulmonary veins in clinical practice. 4D BF-STIC was superior in detecting the greatest number of pulmonary veins before 32 gestational weeks, but had limited clinical usage because it was very time-consuming and experience-dependent. The 4D method should be considered as a complement to traditional two-Dimensional sonography, because it facilitates understanding of the anatomy and the spatial relationships of the cardiac structures. © 2012 John Wiley & Sons, Ltd.