Engineering Commons^™

Comparison Of Left Ventricular Strains And Torsion Derived From Feature Tracking And Dense Cmr, Gregory J. Wehner, Linyuan Jing, Christopher M. Haggerty, Jonathan D. Suever, Jing Chen, Sean M. Hamlet, Jared A. Feindt, Walter Dimitri Mojsejenko, Mark A. Fogel, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

Background: Cardiovascular magnetic resonance (CMR) feature tracking is increasingly used to quantify cardiac mechanics from cine CMR imaging, although validation against reference standard techniques has been limited. Furthermore, studies have suggested that commonly-derived metrics, such as peak global strain (reported in 63% of feature tracking studies), can be quantified using contours from just two frames – end-diastole (ED) and end-systole (ES) – without requiring tracking software. We hypothesized that mechanics derived from feature tracking would not agree with those derived from a reference standard (displacement-encoding with stimulated echoes (DENSE) imaging), and that peak strain from feature tracking would agree with …

Association Between Left Ventricular Mechanics And Diffuse Myocardial Fibrosis In Patients With Repaired Tetralogy Of Fallot: A Cross-Sectional Study, Christopher M. Haggerty, Jonathan D. Suever, Arichanah Pulenthiran, Abba Mejia-Spiegeler, Gregory J. Wehner, Linyuan Jing, Richard J. Charnigo, Brandon K. Fornwalt, Mark A. Fogel

Biomedical Engineering Faculty Publications

Background: Patients with repaired tetralogy of Fallot (TOF) have progressive, adverse biventricular remodeling, leading to abnormal contractile mechanics. Defining the mechanisms underlying this dysfunction, such as diffuse myocardial fibrosis, may provide insights into poor long-term outcomes. We hypothesized that left ventricular (LV) diffuse fibrosis is related to impaired LV mechanics.

Methods: Patients with TOF were evaluated with cardiac magnetic resonance in which modified Look-Locker (MOLLI) T1-mapping and spiral cine Displacement encoding (DENSE) sequences were acquired at three LV short-axis positions. Linear mixed modeling was used to define the association between regional LV mechanics from DENSE based on regional T1-derived diffuse …

Impaired Right Ventricular Contractile Function In Childhood Obesity And Its Association With Right And Left Ventricular Changes: A Cine Dense Cardiac Magnetic Resonance Study, Linyuan Jing, Arichanah Pulenthiran, Christopher D. Nevius, Abba Mejia-Spiegeler, Jonathan D. Suever, Gregory J. Wehner, H. Lester Kirchner, Christopher M. Haggerty, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

Background: Pediatric obesity is a growing public health problem, which is associated with increased risk of cardiovascular disease and premature death. Left ventricular (LV) remodeling (increased myocardial mass and thickness) and contractile dysfunction (impaired longitudinal strain) have been documented in obese children, but little attention has been paid to the right ventricle (RV). We hypothesized that obese/overweight children would have evidence of RV remodeling and contractile dysfunction.

Methods: One hundred and three children, ages 8–18 years, were prospectively recruited and underwent cardiovascular magnetic resonance (CMR), including both standard cine imaging and displacement encoding with stimulated echoes (DENSE) imaging, which allowed …

2d Cine Dense With Low Encoding Frequencies Accurately Quantifies Cardiac Mechanics With Improved Image Characteristics, Gregory J. Wehner, Jonathan D. Grabau, Jonathan D. Suever, Christopher M. Haggerty, Linyuan Jing, David Powell, Sean M. Hamlet, Moriel H. Vandsburger, Xiaodong Zhong, Brandon K. Fornwalt

Biomedical Engineering Faculty Publications

BACKGROUND: Displacement Encoding with Stimulated Echoes (DENSE) encodes displacement into the phase of the magnetic resonance signal. The encoding frequency (k_e) maps the measured phase to tissue displacement while the strength of the encoding gradients affects image quality. 2D cine DENSE studies have used a k_e of 0.10 cycles/mm, which is high enough to remove an artifact-generating echo from k-space, provide high sensitivity to tissue displacements, and dephase the blood pool. However, through-plane dephasing can remove the unwanted echo and dephase the blood pool without relying on high k_e. Additionally, the high sensitivity comes …