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BACKGROUND The local environment of delivered mesenchymal stem cells (MSCs) may affect their ultimate phenotype. MR fluoroscopy has the potential to guide intramyocardial MSC injection to desirable targets, such as the border between infarcted and normal tissue. We tested the ability to (1) identify infarcts, (2) navigate injection catheters to preselected(More)
BACKGROUND Delivery and tracking of endomyocardial stem cells are limited by the inability to image transplanted cells noninvasively in the beating heart. We hypothesized that mesenchymal stem cells (MSCs) could be labeled with a iron fluorophore particle (IFP) to provide MRI contrast in vivo to assess immediate and long-term localization. METHODS AND(More)
C ase presentation A: A 50-year-old diabetic man presented to the hospital after 8 hours of continuous chest pain. Because of acute myocardial in-farction of the anterior wall, he underwent direct stenting to an occlusion in the left anterior descending coronary artery. Despite revascularization, sub-optimal coronary flow was achieved, and he subsequently(More)
Microvascular obstruction (MVO) commonly occurs following percutaneous coronary interventions (PCI), may lead to myocardial injury, and is an independent predictor of adverse outcome. Severe MVO may manifest angiographically as reduced flow in the patent upstream epicardial arteries, a situation that is termed "no-reflow." Microvascular obstruction can be(More)
RATIONALE AND OBJECTIVES A fully automated left ventricle segmentation method for the functional analysis of cine short axis (SAX) magnetic resonance (MR) images was developed, and its performance evaluated with 133 studies of subjects with diverse pathology: ischemic heart failure (n=34), non-ischemic heart failure (n=30), hypertrophy (n=32), and healthy(More)
OBJECTIVES This study tested the hypotheses that endografts can be visualized and navigated in vivo solely under real-time magnetic resonance imaging (rtMRI) guidance to repair experimental abdominal aortic aneurysms (AAA) in swine, and that MRI can provide immediate assessment of endograft apposition and aneurysm exclusion. BACKGROUND Endovascular repair(More)
T2 relaxation can augment delayed-enhancement viability imaging because it is sensitive to tissue edema and microcirculatory oxygen state. We demonstrate the T2 'signatures' of sub-lethal ischemia and stunning in porcine myocardium perfused by the distal left anterior descending artery, by imaging during percutaneous balloon occlusion for 25 minutes and(More)
PURPOSE Currently, the use of cine magnetic resonance imaging (MRI) to identify cardiac quiescent periods relative to the electrocardiogram (ECG) signal is insufficient for producing submillimeter-resolution coronary MR angiography (MRA) images. In this work, the authors perform a time series comparison between tissue Doppler echocardiograms of the(More)
The aim of this work was to demonstrate the correspondence between a macroscopic 3D computer model of electrophysiology (i.e., the Aliev-Panfilov model) parametrized with MR data and experimental characterization of action potential propagation in large porcine hearts, ex vivo, using optical methods (based on voltage-sensitive fluorescence). A secondary(More)