Conferences, Lectures, & Seminars
Events for July
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4D Blood Flow in the Human Heart: Optimal Vortex Ring Formation and Validation Challenges
Tue, Jul 07, 2015 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Johannes Töger, Lund University
Talk Title: 4D Blood Flow in the Human Heart: Optimal Vortex Ring Formation and Validation Challenges
Series: Medical Imaging Seminar Series
Abstract: Diastolic dysfunction, i.e. dysfunction of the filling mechanisms of the left ventricle (LV) of the heart, is a disease with poor prognosis even in its mild form [1] and new measures of diastolic dysfunction may improve patient care. During the early phase of diastole (filling) of the human heart, a vortex ring forms in the left ventricle (LV) downstream from the mitral valve [2, 3]. Features of the vortex ring has been shown to reflect overall cardiac function [3, 4] and may therefore give new insights into the pathophysiology of diastole.
The full three-dimensional dynamics of the vortex ring can be imaged using 4D flow magnetic resonance imaging and mathematical post-processing by Lagrangian Coherent Structures (LCS), a flow analysis tool based on the theory of nonlinear dynamical systems (Figure 1). Furthermore, we have constructed a flow phantom for validation of 4D flow measurements of pulsatile flow (Figure 2) using particle imaging velocimetry (PIV) and planar laser-induced fluorescence (PLIF), meeting the formidable design challenge of producing a pulsatile, physiological, fully three-dimensional and highly repeatable experiment [5].
In vivo studies, healthy volunteers (n=23) and patients with heart failure (n=23) [6, 7] show that the healthy heart displays a matching between the volume of the vortex ring and the volume of the LV that is lost in heart failure. Furthermore, the mixing of blood in the vortex ring is increased in heart failure patients compared to healthy hearts, which may reflect the impaired diastolic function in the patients.
Host: Prof. Krishna Nayak
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 132
Audiences: Everyone Is Invited
Contact: Talyia White
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor. -
Data Acquisition for Quantitative Breast MRI
Tue, Jul 28, 2015 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Brian Hargreaves, Stanford School of Medicine
Talk Title: Data Acquisition for Quantitative Breast MRI
Series: Medical Imaging Seminar Series
Abstract: This talk will cover acquisition approaches for quantitative breast MRI techniques to assess perfusion and diffusion. Perfusion is typically measured using dynamic contrast-enhanced acquisition, which forces a trade-off between temporal and spatial resolution. Advanced sampling schemes that include considerations for fat suppression will be shown including randomized sampling, parallel imaging and compressed sensing. Diffusion-weighted MRI is challenging since motion corrupts acquisitions. Two approaches are (1) to acquire single-shot images that are limited in resolution or (2) to acquire multi-shot images and correct for motion. Variations of the multi-shot approach including multi-band acquisition and steady-state acquisitions will be described.
Host: Professor Krishna Nayak
Location: Hughes Aircraft Electrical Engineering Center (EEB) - EEB 132
Audiences: Everyone Is Invited
Contact: Talyia White
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor.
