Witschey Cardiovascular Imaging

• Development of Noncontrast MRI Methods for Cardiovascular Disease

The research goal is to investigate cardiovascular disease using noncontrast MRI methods and to translate these methods to the clinic. One hypothesis is that myocardial MR relaxation times change due to physiologic fibrosis in athletes. MRI would provide a noninvasive and ethical means to investigate how physiologic cardiac remodeling in athletes is connected to pathophysiologic remodeling following myocardial infarction. Another hypothesis is that MR-relaxation times will be a predictor of future outcome of LV remodeling intervention. This hypothesis is highly appropriate because of my previous training in interventional and therapeutic techniques to prevent adverse remodeling following myocardial infarction.

• Characterization of Cardiac Hemodynamics and Response to Intervention

The goal of this research is to investigate cardiac (3-spatial coordinates and time) hemodynamics to measure changes in LV blood flow with devices that alters infarct or LV material properties. The interventional device is placed on the epicardial surface and can be adjusted to stiffen the infarct region. In vivo testing has demonstrated that the device alters global function and redistributes the cavity volume from the infarct region to the normally contracting remote region. Using 4D blood flow imaging techniques, we can quantify the effect of infarct stiffening on the flow distribution. This project provides a perfect opportunity develop new skills with cardiac MRI image acquisition using state-of-the-art flow, strain, delayed enhanced, and real-time MR image acquisitions.

• Development of Advanced MR Methodology

The goal of this research is the development of basic MR methodology and techniques and to apply these techniques to cardiovascular disease.

• Nonlinear Magnetic Fields

The goal of this research is the development of the MR physics and applications of nonlinear magnetic fields. Two potentially valuable techniques using nonlinear magnetic field gradients are dynamic shim updating of the magnetic field during MR acquisitions and gradient localization.