Daniel Ennis

Learn 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)
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 objective of this study was to quantify microstruc-tural 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)
The aim of this paper is to model and visualize cardiovascular deformations in order to better understand vascular movements inside the lung and heart caused by abnormal cardiac conditions. The modeling was performed in two steps: first step involved modeling the cardiac output taking into account of the heart rate and preload blood volume, contractility(More)
PURPOSE Dynamic MRI is an attractive tool for internal organ motion monitoring but its speed is yet to be improved for real time 3D imaging. The purpose of the study is to accelerate the imaging acquisition using a hybrid compressed-sensing and low rank decomposition method (k-t SLR) exploiting data sparsity in the spatial-temporal domain. METHODS Six(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)