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High-dimensional deformable registration of MRI brain images is presented here. The deformation is driven by local forces estimated from point similarities based on joint histogram and with the use of prior information obtained from tissue probability maps available in selected commonly used brain atlases. Three point similarity measures are tested in an experiment with data obtained from standard...
This paper describes an approach to fine scale non-rigid registration for mapping patterns of tissue volume loss in serial MRI studies of the brain. Specifically it addresses the important confound of diffuse tissue contrast changes which can influence local sub-voxel estimates of volume change. Such changes can be induced by neurodegenerative or neurodevelopmental processes, which not only modify...
The effectiveness of reperfusion therapies during acute brain ischemia depends on the viability of the underperfused tissue. Specifically, when the ischemia tissue is viable reperfusion leads to improved clinical outcome. However, when the ischemic tissue is non-viable, reperfusion therapy can lead to intra-cerebral hemorrhage and/or an accelerated rate of ischemia formation. Perfusion and diffusion...
Image signal-to-noise ratio (SNR) and signal intensity (SI) inhomogeneities are factors that strongly affect the accuracy and precision of brain tissue segmentations in magnetic resonance image (MRI). In this work, SNR and contrast of brain images are optimized by TR and inversion recovery time TI in multi-spectrum MRI data sets. SI inhomogeneities are measured in vivo using a recently developed method...
The primary goal in this study was to investigate 3-D dose distribution, near the areas of tissue inhomogeneities, in Gamma Knife radiosurgery with the gel dosimetry. The spherical glass balloon of a diameter of 16 cm filled with the gel forms the homogeneous phantom; and an identical balloon with two corks placed on each side to represent the air cavities forms the inhomogeneous phantom. Dose calibration...
Most microscopic imaging techniques do not have the resolution to visualize individual collagen fibrils in articular cartilage, which possesses unique depth-dependent anisotropy and noticeable topographical heterogeneity. These imaging studies therefore deal with the averaged properties of the tissue. In this report, an ellipse model is introduced to explore the common connections between the anisotropic...
With the increasing importance of molecular and cellular biology, a new type of medicine, molecular based medicine, is now developing. This will significantly alter the way in which medicine is practiced. Central to these developments is the concept of the biological continuum (BC). Medicine today is often practiced at one or two of these levels, i.e. there is generally no vertically integrated approach...
In the paper we describe a Web-based interface to view 2-D and 3-D results generated from segmentation and measurement process interactively. Our implementation takes a fully Web-based approach to provide universal access and visualization to a wide range of patient data (i.e. at multiple locations). An example case study is presented: thickness measurement of articular cartilage from MR knee images...
Quantification of the sensitivity of the electro-cardiographic forward problem to various parameters can effectively direct the generalization of patient specific models without significant loss in accuracy. To this purpose we applied polynomial chaos based stochastic finite elements to assess the effect of variations in the distributions of tissue conductivity in a two-dimensional torso geometry...
This paper presents T2-MRI as a very promising method to investigate the pathophysiology of electrical shock injuries, permitting distinction between thermal and electroporation damaged tissue and permitting monitoring of the therapeutic efficacy of membrane sealing surfactants
Accurate assessment of total body and the distribution of regional adipose tissue is a critical problem emerging in the United States. Using manual segmentation of MRI scanned images is a problem due to the high variation between manual delineations. Manual segmentation also requires highly trained experts with knowledge of anatomy. In this study, we used a specific water saturation sequence and histogram...
Magnetic resonance elastography (MRE) is a noninvasive technique to measure elasticity of tissues in vivo. For MRE, an additional actuator is needed to be mounted on an observed object, and to excite the object. In this paper, an experiment is set to obtain MR mechanical shear wave images. A novel actuator is proposed to generate mechanical wave propagating inside a gel phantom. The actuator is made...
Diffusion tensor magnetic resonance imaging (DTI) has the ability to provide non-invasive information on tissue microstructure not available in routine clinical MRI images. This includes information regarding the degree of anisotropy as well as the direction of the diffusion of water molecules within the tissues. Since white matter areas of the brain have an ordered structure (due to the myelination...
Dynamic contrast-enhanced (DCE) MR cardiac imaging has been recognized as a unique and powerful tool for assessing both cardiac functions and physiological conditions of the heart tissues (e.g., tissue rejection following heart transplantation). However, because of cardiac motion and the limited data acquisition speed of existing MRI techniques, it has been very difficult to acquire dynamic images...
Magnetic resonance (MR) elastography has the ability to combine the inherent soft-tissue contrast of traditional MR imaging with quantitative maps of tissue stiffness. Mechanical properties of tissues can vary greatly with disease and degeneration, and can illuminate structure-function understanding of tissues. Dynamic MR elastography is a phase contrast-based method for imaging the transmission of...
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