Daniel Ennis

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The objective of this study was to quantify microstructural remodeling in peri-infarcted and infarcted porcine myocardium using diffusion tensor MRI (DT-MRI) for the first time. High resolution ex vivo late gadolinium enhanced (LGE) MRI was used to segment the DT-MRI data into normal, peri-infarct and infarcted myocardium. LGE-MRI based segmentation(More)
Left ventricular (LV) twist mechanics and regional strain during cardiac sympathetic efferent activation are poorly understood. The purpose of this study was to compare the effects of left stellate ganglia (LSG) and right stellate ganglia (RSG) stimulation on cardiac twist/untiwst mechanics and regional strain. In nine pigs, echocardiographic imaging and LV(More)
The aim of this paper is to enable model guided multi-scale and multi-modal image integration for the head and neck anatomy. The image modality used for this purpose includes multi-pose Magnetic Resonance Imaging (MRI), Mega Voltage CT, and hand-held Optical Coherence Tomography. A biomechanical model that incorporates subject-specific young's modulus and(More)
PURPOSE To evaluate a low-rank decomposition method to reconstruct down-sampled k-space data for the purpose of tumor tracking. METHODS AND MATERIALS Seven retrospective lung cancer patients were included in the simulation study. The fully-sampled k-space data were first generated from existing 2-dimensional dynamic MR images and then down-sampled by 5 ×(More)
PURPOSE Radiation Therapy (RT) induced pulmonary function change may depend on the location, underlying function of that lung prior to radiations, radiation dose/fractionation and other factors. We propose to evaluate the radiation induced pulmonary function change using static breath-hold MRI scans with vascular information and 3D deformable image(More)
PURPOSE The purpose of this work is to develop a cardiac-induced lung motion model to be integrated into an existing breathing motion model. METHODS The authors' proposed cardiac-induced lung motion model represents the lung tissue's specific response to the subject's cardiac cycle. The model is mathematically defined as a product of a converging(More)
PURPOSE To improve the accuracy of a quantitative breathing motion model by developing a cardiac-induced lung tissue motion model from MRI data. METHODS 10 healthy volunteers were imaged on a 1.5T MR-scanner. A total of 24 short-axis and 18 radial views were acquired during a series of 12-15s breath-holds. The planar views were combined to create a 3D(More)
PURPOSE In this abstract, we discuss a biomechanical head and neck model that will be able to represent patient setup variations as well as physiologic changes and subsequently enable dose calculations on the deformed anatomy. METHODS We selected Multi Pose MRI as the imaging modality to aid in model development and validation. The MRI data allowed us to(More)
Background Diffusion tensor magnetic resonance imaging (DT-MRI) enables 3D evaluation of whole heart microstructure. DT invariants evaluate microstructural remodeling by quantifying trace (increases with decreasing cellularity), fractional anisotropy (FA, decreases with increasing fibrosis), and tissue mode (decreases with increasing fiber disarray) [1]. We(More)