Three-Dimensional Embedded Attentive RNN (3D-EAR) Segmentor for Left Ventricle Delineation from Myocardial Velocity Mapping

Abstract We carry out a comprehensive kinematic and morphological study of the asymmetrical planetary nebula: NGC 6210, known as the Turtle. The nebula’s spectacularly chaotic appearance has led to proposals that it was shaped by mass transfer in a triple star system. We study the three-dimensional structure and kinematics of its shells, lobes, knots, and haloes by combining radial velocity mapping from multiple long-slit spectra with proper motion measurements from multi-epoch imaging. We find that the nebula has five distinct ejection axes. The first is the axis of the bipolar, wind-blown inner shell, while the second is the axis of the lop-sided, elliptical, fainter, but more massive intermediate shell. A further two axes are bipolar flows that form the point symmetric, high-ionization outer lobes, all with inclinations close to the plane of the sky. The final axis, which is inclined close to the line of sight, traces collimated outflows of low-ionization knots. We detect major changes in outflow directions during the planetary nebula phase, starting at or before the initial ionization of the nebula 3500 years ago. Most notably, the majority of redshifted low-ionization knots have kinematic ages greater than 2000 years, whereas the majority of blueshifted knots have ages younger than 2000 years. Such a sudden and permanent 180-degree flip in the ejection axis at a relatively late stage in the nebular evolution is a challenge to models of planetary nebula formation and shaping.

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Three-dimensional active shape model matching for left ventricle segmentation in cardiac CT

10.1117/12.481314 ◽

2003 ◽

Cited By ~ 3

Author(s):

Hans C. van Assen ◽

Rob J. van der Geest ◽

Mikhail G. Danilouchkine ◽

Hildo J. Lamb ◽

Johan H. C. Reiber ◽

...

Keyword(s):

Left Ventricle ◽

Cardiac Ct ◽

Three Dimensional ◽

Active Shape Model ◽

Model Matching ◽

Shape Model ◽

Active Shape ◽

Ventricle Segmentation

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Long-term prognostic significance of three-dimensional echocardiographic parameters of the left ventricle and left atrium

European Journal of Echocardiography ◽

10.1093/ejechocard/jep198 ◽

2009 ◽

Vol 11 (3) ◽

pp. 250-256 ◽

Cited By ~ 51

Author(s):

S. Caselli ◽

E. Canali ◽

M. L. Foschi ◽

D. Santini ◽

E. Di Angelantonio ◽

...

Keyword(s):

Left Ventricle ◽

Left Atrium ◽

Prognostic Significance ◽

Three Dimensional ◽

Echocardiographic Parameters

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ASYNCHRONOUS ONSET OF MECHANICAL SYSTOLE STUDIED BY COMPUTER GENERATED THREE-DIMENSIONAL FUNCTIONAL IMAGES OF THE LEFT VENTRICLE

Biomedical Engineering I ◽

10.1016/b978-0-08-028826-0.50025-1 ◽

1982 ◽

pp. 99-102

Author(s):

Gautam Ray ◽

Donald H. Schmidt

Keyword(s):

Left Ventricle ◽

Three Dimensional ◽

Functional Images

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Novel CMR techniques for advanced surgical planning

The EACVI Textbook of Cardiovascular Magnetic Resonance ◽

10.1093/med/9780198779735.003.0049 ◽

2018 ◽

pp. 502-508

Author(s):

Mark A Fogel

Keyword(s):

Magnetic Resonance ◽

Fluid Dynamic ◽

Three Dimensional ◽

Dynamic Modelling ◽

Surgical Care ◽

Velocity Mapping ◽

Three Dimensional Printing ◽

Improved Outcomes ◽

Medical Advances ◽

Dimensional Printing

Medical and surgical care for the patient with congenital heart disease (CHD) has advanced greatly over the past 40 years; along with improved surgical and catheter-based techniques, intensive unit care, and overall medical advances, improved outcomes have accrued across a whole host of cardiac defects. This is owed, in no small part, to advances in imaging and cardiovascular magnetic resonance (CMR) which has played an important and growing role in this evolution. Novel CMR techniques 25 years ago, such as gadolinium-based imaging and two-dimensional velocity mapping, are now commonplace. At the cutting edge of novel CMR techniques, in the current era, are computational fluid dynamic modelling, three-dimensional printing, four-dimensional flow imaging, and X-ray magnetic resonance/interventional CMR, which will be the focus of this chapter. The hope is that one day these techniques will be the commonplace ones, aiding in the care of a broad spectrum of CHD.

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Three-dimensional residual strain in midanterior canine left ventricle

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1997.273.4.h1968 ◽

1997 ◽

Vol 273 (4) ◽

pp. H1968-H1976 ◽

Cited By ~ 29

Author(s):

Kevin D. Costa ◽

Karen May-Newman ◽

Dyan Farr ◽

Walter G. O’Dell ◽

Andrew D. McCulloch ◽

...

Keyword(s):

Residual Stress ◽

Left Ventricle ◽

Residual Strain ◽

Three Dimensional ◽

Element Analysis ◽

Primary Mechanism ◽

Dimensional Measurements ◽

Residual Strains ◽

Shear Strains ◽

Pressure State

All previous studies of residual strain in the ventricular wall have been based on one- or two-dimensional measurements. Transmural distributions of three-dimensional (3-D) residual strains were measured by biplane radiography of columns of lead beads implanted in the midanterior free wall of the canine left ventricle (LV). 3-D bead coordinates were reconstructed with the isolated arrested LV in the zero-pressure state and again after local residual stress had been relieved by excising a transmural block of tissue. Nonhomogeneous 3-D residual strains were computed by finite element analysis. Mean ± SD ( n = 8) circumferential residual strain indicated that the intact unloaded myocardium was prestretched at the epicardium (0.07 ± 0.06) and compressed in the subendocardium (−0.04 ± 0.05). Small but significant longitudinal shortening and torsional shear residual strains were also measured. Residual fiber strain was tensile at the epicardium (0.05 ± 0.06) and compressive in the subendocardium (−0.01 ± 0.04), with residual extension and shortening, respectively, along structural axes parallel and perpendicular to the laminar myocardial sheets. Relatively small residual shear strains with respect to the myofiber sheets suggest that prestretching in the plane of the myocardial laminae may be a primary mechanism of residual stress in the LV.

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Effects of ventricular pacing on finite deformation in canine left ventricles

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.1987.252.5.h1023 ◽

1987 ◽

Vol 252 (5) ◽

pp. H1023-H1030 ◽

Cited By ~ 8

Author(s):

L. K. Waldman ◽

J. W. Covell

Keyword(s):

Left Ventricle ◽

Finite Deformation ◽

Repeated Measures ◽

Three Dimensional ◽

Radial Strain ◽

Tangent Plane ◽

Ventricular Pacing ◽

Anesthetized Dogs ◽

Principal Directions ◽

Heart Wall

Despite the fact that myofibers would be expected to shorten only along their axes, there is now evidence for substantial deformation away from the local myofiber direction in the left ventricle. To determine if the principal directions of deformation could be altered by a physiological stimulus, we examined local three-dimensional finite deformation in the anterior free wall of the left ventricle during normal atrial activation (AA) and, subsequently, during epicardial ventricular pacing (VP) at the site of deformation measurement in open-chest anesthetized dogs. An analysis of variance by repeated measures revealed the following significant changes (P less than or equal to 0.05) in the overall (average of epicardial and endocardial data) strain variables at end systole. Circumferential strain increased from -0.07 (AA) to 0.14 (VP), radial strain decreased from 0.16 (AA) to 0.01 (VP), shear in the tangent plane of the local epicardium decreased from 0.04 (AA) to -0.02 (VP), shear in the plane of the longitudinal and radial coordinates decreased from 0.03 (AA) to -0.03 (VP). Neither the first (greatest shortening) nor the third (greatest lengthening) principal strain changed significantly, but the direction of the first principal axis of deformation projected on the epicardial tangent plane changed from -51 degrees (AA) to -80 degrees (VP) from circumferential. In addition, substantial tipping of the plane of principal shortening away from the epicardial tangent plane was observed, particularly with ventricular pacing. These data indicate that the principal directions of deformation can be altered substantially by changing the activation sequence. In conjunction with the observed shearing deformations, particularly near the endocardium, they support the concept that locally the heart wall deforms as a unit with significant transmural tethering.

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Method for Calibration of Left Ventricle Material Properties Using Three-Dimensional Echocardiography Endocardial Strains

Journal of Biomechanical Engineering ◽

10.1115/1.4044215 ◽

2019 ◽

Vol 141 (9) ◽

Cited By ~ 4

Author(s):

Yaghoub Dabiri ◽

Kevin L. Sack ◽

Nuno Rebelo ◽

Peter Wang ◽

Yunjie Wang ◽

...

Keyword(s):

Mechanical Properties ◽

Left Ventricle ◽

Diffusion Tensor ◽

Diastolic Pressure ◽

Three Dimensional ◽

Heart Association ◽

Mean Difference ◽

Imaging Data ◽

The Mean

We sought to calibrate mechanical properties of left ventricle (LV) based on three-dimensional (3D) speckle tracking echocardiographic imaging data recorded from 16 segments defined by American Heart Association (AHA). The in vivo data were used to create finite element (FE) LV and biventricular (BV) models. The orientation of the fibers in the LV model was rule based, but diffusion tensor magnetic resonance imaging (MRI) data were used for the fiber directions in the BV model. A nonlinear fiber-reinforced constitutive equation was used to describe the passive behavior of the myocardium, whereas the active tension was described by a model based on tissue contraction (Tmax). isight was used for optimization, which used abaqus as the forward solver (Simulia, Providence, RI). The calibration of passive properties based on the end diastolic pressure volume relation (EDPVR) curve resulted in relatively good agreement (mean error = −0.04 ml). The difference between the experimental and computational strains decreased after segmental strain metrics, rather than global metrics, were used for calibration: for the LV model, the mean difference reduced from 0.129 to 0.046 (circumferential) and from 0.076 to 0.059 (longitudinal); for the BV model, the mean difference nearly did not change in the circumferential direction (0.061) but reduced in the longitudinal direction from 0.076 to 0.055. The calibration of mechanical properties for myocardium can be improved using segmental strain metrics. The importance of realistic fiber orientation and geometry for modeling of the LV was shown.

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