3-Dimensional Ultrasound Elasticity Imaging for Quantitative Cardiac Mechanical Property Assessment: A Numerical Approach

2010 ◽  
Author(s):  
S. Tripathy ◽  
M. A. Simon ◽  
M. S. Sacks ◽  
J. C. Brigham ◽  
K. Kim
Keyword(s):  
Mechanical Property ◽  
Cardiac Tissue ◽  
Imaging Techniques ◽  
Numerical Approach ◽  
3D Ultrasound ◽  
Planar Geometry ◽  
Data Generation ◽  
Elasticity Imaging ◽  
3 Dimensional ◽  
Property Assessment

Quantitative assessment of the cardiac tissue mechanical property or contractility is essential for the prognosis and treatment of various cardiac diseases such as myocardial infarction, pulmonary hypertension, and heart failure. Current evaluation methods are either invasive or limited, mainly due to complex 3-dimensional (3D) geometry and deformation of a heart. 2D imaging techniques assume erroneous planar geometry and deformations, while available 3D imaging techniques have limited functional assessment. Correlation-based 3D ultrasound (US) elasticity imaging (UEI) provides both anatomical and functional information such as mechanical property change of the cardiac walls, which is important for diagnosis and monitoring of the treatment. Using finite element (FE) techniques, one and two ellipsoid chamber cardiac mechanical models were developed, and combined with 3D US radio frequency (RF) data generation program. 3D UEI on the synthesized 3D US volume images were quantitatively analyzed and compared with 2D UEI.

Mechanical Property Assessment of Bone Healing around a Titanium-Zirconium Alloy Dental Implant

2013 ◽  
Vol 16 (6) ◽  
pp. 913-919 ◽  
Author(s):  
Rodolfo B. Anchieta ◽  
Marta Baldassarri ◽  
Fernando Guastaldi ◽  
Nick Tovar ◽  
Malvin N. Janal ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Dental Implant ◽  
Bone Healing ◽  
Zirconium Alloy ◽  
Titanium Zirconium ◽  
Property Assessment

Bioengineered Cardiac Grafts

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Jonathan Leor ◽  
Sharon Aboulafia-Etzion ◽  
Ayelet Dar ◽  
Lilia Shapiro ◽  
Israel M. Barbash ◽  
...  
Keyword(s):  
Cardiac Tissue ◽  
Left Ventricular ◽  
Cardiac Cells ◽  
Sham Operation ◽  
Complete Disappearance ◽  
3 Dimensional ◽  
Infarcted Myocardium ◽  
Lv Remodeling ◽  
And Function ◽  
Conducive Environment

Background —The myocardium is unable to regenerate because cardiomyocytes cannot replicate after injury. The heart is therefore an attractive target for tissue engineering to replace infarcted myocardium and enhance cardiac function. We tested the feasibility of bioengineering cardiac tissue within novel 3-dimensional (3D) scaffolds. Methods and Results —We isolated and grew fetal cardiac cells within 3D porous alginate scaffolds. The cell constructs were cultured for 4 days to evaluate viability and morphology before implantation. Light microscopy revealed that within 2 to 3 days in culture, the dissociated cardiac cells form distinctive, multicellular contracting aggregates within the scaffold pores. Seven days after myocardial infarction, rats were randomized to biograft implantation (n=6) or sham-operation (n=6) into the myocardial scar. Echocardiography study was performed before and 65±5 days after implantation to assess left ventricular (LV) remodeling and function. Hearts were harvested 9 weeks after implantation. Visual examination of the biograft revealed intensive neovascularization from the neighboring coronary network. Histological examination revealed the presence of myofibers embedded in collagen fibers and a large number of blood vessels. The specimens showed almost complete disappearance of the scaffold and good integration into the host. Although control animals developed significant LV dilatation accompanied by progressive deterioration in LV contractility, in the biograft-treated rats, attenuation of LV dilatation and no change in LV contractility were observed. Conclusions —Alginate scaffolds provide a conducive environment to facilitate the 3D culturing of cardiac cells. After implantation into the infarcted myocardium, the biografts stimulated intense neovascularization and attenuated LV dilatation and failure in experimental rats compared with controls. This strategy can be used for regeneration and healing of the infarcted myocardium.

scholarly journals Electrostriction Effects During Defibrillation

2007 ◽  
Vol 6 (2) ◽  
Author(s):  
Michelle Fritz ◽  
Phil Prior ◽  
Bradley Roth
Keyword(s):  
Electric Field ◽  
Cardiac Tissue ◽  
Imaging Techniques ◽  
Stress And Strain ◽  
Mechanical Forces ◽  
Physical Origin ◽  
Anisotropic Cylinder ◽  
Simple Geometry ◽  
Complicated Manner ◽  
A Charge

Background—The electric field applied to the heart during defibrillation causes mechanical forces (electrostriction), and as a result the heart deforms. This paper analyses the physical origin of the deformation, and how significant it is. Methods—We represent the heart as an anisotropic cylinder. This simple geometry allows us to obtain analytical solutions for the potential, current density, charge, stress, and strain. Results—Charge induced on the heart surface in the presence of the electric field results in forces that deform the heart. In addition, the anisotropy of cardiac tissue creates a charge density throughout the tissue volume, leading to body forces. These two forces cause the tissue to deform in a complicated manner, with the anisotropy suppressing radial displacements in favor of tangential ones. Quantitatively, the deformation of the tissue is small, although it may be significant when using some imaging techniques that require the measurement of small displacements. Conclusions—The anisotropy of cardiac tissue produces qualitatively new mechanical behavior during a strong, defibrillation-strength electric shock.

scholarly journals Non-invasive Cardiac Radiation for Ablation of Ventricular Tachycardia: a New Therapeutic Paradigm in Electrophysiology

2018 ◽  
Vol 7 (1) ◽  
pp. 8 ◽  
Author(s):  
Eun-Jeong Kim ◽  
Giovanni Davogustto ◽  
William G Stevenson ◽  
Roy M John ◽  
◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Cardiac Tissue ◽  
Imaging Techniques ◽  
Case Series ◽  
Structural Heart Disease ◽  
Multicenter Studies ◽  
Invasive Approach ◽  
Non Invasive ◽  
Surface Ecg ◽  
Early Case

Non-invasive ablation of cardiac tissue to control ventricular tachycardia (VT) is a novel therapeutic consideration in the management of ventricular arrhythmias associated with structural heart disease. The technique involves the use of stereotactic radiotherapy delivered to VT substrates. Although invasive mapping can be used to identify the target, the use of non-invasive ECG and imaging techniques combined with multi-electrode body-surface ECG recordings offers the potential of a completely non-invasive approach. Early case series have demonstrated a consistent decrease in VT burden and sufficient early safety to allow more detailed multicenter studies. Such studies are currently in progress to further evaluate this promising technology.

Characterization of controlled bone defects using 2D and 3D ultrasound imaging techniques

2010 ◽  
Vol 55 (16) ◽  
pp. 4839-4859 ◽  
Author(s):  
Biren J Parmar ◽  
Whitney Longsine ◽  
Eric P Sabonghy ◽  
Arum Han ◽  
Ennio Tasciotti ◽  
...  
Keyword(s):  
Ultrasound Imaging ◽  
Imaging Techniques ◽  
3D Ultrasound ◽  
Bone Defects ◽  
2D And 3D

Surface mechanical property assessment of ultra-thin HfO2 films

2013 ◽  
Vol 544 ◽  
pp. 212-217 ◽  
Author(s):  
Wei-En Fu ◽  
Bo-Ching He ◽  
Yong-Qing Chang
Keyword(s):  
Mechanical Property ◽  
Property Assessment

scholarly journals Article Commentary: Cost-Effective Screening for Breast Cancer Worldwide: Current State and Future Directions

2008 ◽  
Vol 1 ◽  
pp. BCBCR.S774 ◽  
Author(s):  
A. Sarvazyan ◽  
V. Egorov ◽  
J.S. Son ◽  
C.S. Kaufman
Keyword(s):  
Breast Cancer ◽  
Cancer Screening ◽  
Breast Cancer Screening ◽  
Imaging Techniques ◽  
Clinical Breast Examination ◽  
Cost Effective ◽  
Cancer Diagnostics ◽  
Elasticity Imaging ◽  
Diagnostic Potential ◽  
Tactile Imaging

Affordability of healthcare is highly limited by its skyrocketing cost. Access to screening and diagnostic medical equipment and medicine in developing countries is inadequate for the majority of the population. There is a tremendous worldwide need to detect breast cancer at its earliest stage. These needs must be balanced by the ability of countries to provide breast cancer screening technology to their populations. We reviewed the diagnostic accuracy, procedure cost and cost-effectiveness of currently available technique for breast screening and diagnosis including clinical breast examination, mammography, ultrasound, magnetic resonance imaging, biopsy and a new modality for cancer diagnostics termed elasticity imaging that has emerged in the last decade. Clinical results demonstrate that elasticity imaging even in its simplest and least sophisticated versions, like tactile imaging, has significant diagnostic potential comparable and exceeding that of conventional imaging techniques. In view of many countries with limited resources, effective yet less expensive modes of screening must be considered worldwide. The tactile imaging is one method that has the potential to provide cost-effective breast cancer screening and diagnostics.

scholarly journals Localized mechanical property assessment of SiC/SiC composite materials

2015 ◽  
Vol 70 ◽  
pp. 93-101 ◽  
Author(s):  
D. Frazer ◽  
M.D. Abad ◽  
D. Krumwiede ◽  
C.A. Back ◽  
H.E. Khalifa ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Composite Materials ◽  
Property Assessment
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