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A number of MRI applications rely on dynamic phase information embedded in the acquired images. Such applications often require multiple acquisitions, leading to possibly long scan time and low temporal resolution. Previously, SENSE method has been used for phase-sensitive data to shorten acquisition time. However, SENSE can be subject to artifacts due to inaccurate coil sensitivities and low SNR...
Neuroblastoma is a childhood cancer of the nervous system. Current prognostic classification of this disease partly relies on morphological characteristics of the cells from H&E-stained images. In this work, an automated cell nuclei segmentation method is developed. This method employs morphological top-hat by reconstruction algorithm coupled with hysteresis thresholding to both detect and segment...
Potential inverse electrocardiography (PIE) is a method for reconstruction of epicardial potentials from measured body surface electrocardiograms and heart-torso geometry. The method of choice for computing epicardial potentials has been either the boundary element method (BEM) or the finite element method (FEM). These methods require time-consuming meshing of the heart and torso surfaces or the volume...
A recursive algorithm is presented to improve the spatial resolution of 3-D Electrical Impedance Tomography (EIT) images in a four-shell realistic head model. In this algorithm, the low spatial resolution image derived from the standardized low resolution electromagnetic tomography algorithm (sLORETA) is chosen to be the initial estimate for the Focal Underdetermined System Solver (FOCUSS), and a...
The paper presents a novel approach for dynamic magnetic resonance imaging (MRI) cardiac perfusion image reconstruction from sparse k-space data. It formulates the reconstruction problem in an inverse-methods setting. Relevant prior information is incorporated via a parametric model for the perfusion process. This wealth of prior information empowers the proposed method to give high-quality reconstructions...
A number of MRI applications rely on dynamic phase information embedded in the acquired images. Such applications often require multiple acquisitions, leading to possibly long scan time and low temporal resolution. Previously, SENSE method has been used for phase-sensitive data to shorten acquisition time. However, SENSE can be subject to artifacts due to inaccurate coil sensitivities and low SNR...
Susceptibility-weighted magnetic resonance imaging is a powerful tool for high resolution imaging of the vasculature, aiding in the diagnosis of many pathologic conditions. The technique is especially beneficial at higher field strengths where traditional sequences that measure cerebral blood volume suffer from severe distortions, rendering them inapplicable at 7 T. However, conventional susceptibility-weighted...
Molecular imaging is an emerging imaging technique in biological and medical field. Thereinto, bioluminescence tomography (BLT) plays a significant role. In view of the ill-posedness of the BLT problem, a priori knowledge is indispensable to reconstruct bioluminescent source uniquely and quantitatively. In this paper, the anatomical information of a real mouse is obtained with the microCT scanner...
Spiral k-space scanning is a rapid magnetic resonance imaging (MRI) technique that can provide an order of magnitude reduction in scan time compared to conventional spin warp techniques. Parallel imaging is another method for reducing scan time that exploits spatially varying radiofrequency (RF) coil sensitivities to reduce the amount of data required to reconstruct an image. Combining spiral scanning...
A statistical interpretation of existing parallel magnetic resonance imaging methods reveals that the underlying noise model is of additive independent Gaussian noise. In reality MR imaging processes suffer from a variety of noise, errors and other uncertainties. A careful statistical analysis of these uncertainties can potentially allow significant improvement of the reconstruction process. In this...
Optical tomography consists of reconstructing the spatial of a medium's optical properties from measurements of transmitted light on the boundary of the medium. Mathematically this problem amounts to parameter identification for the radiative transport equation (ERT) or diffusion approximation (DA). However, this type of boundary-value problem is highly ill-posed and the image reconstruction process...
Diffuse optical tomography (DOT) is an emerging non-invasive technique for detecting the presence of a tumor or other anomalies from a scattered photon field. In this paper, we derive an alternating projection algorithm to reconstruct the spatially varying absorption coefficient of human brain tissue to detect the presence of tumor. We use a perturbation method and assume the absorption coefficient...
In this paper, a new non-regularization method for positron emission tomography (PET) reconstruction is proposed. The proposed method is a feature-based method using Fourier-Wavelet basis. In order to obtain the reconstructions, we have to calculate the Fourier-Wavelet moment (FWM) from the measurements. To achieve this, iterative method is employed. The rotation invariance property of the proposed...
In a cryo electron microscopy experiment, the data is noisy 2-D projection images of the 3-D electron scattering intensity where the orientation of the projections is not known. In previous work we have developed a solution for this problem based on a maximum likelihood estimator that is computed by an expectation maximization algorithm. In the expectation maximization algorithm the expensive step...
Commercial receivers used for parallel MR imaging often present researchers with hurdles such as high cost-per-channel, low scalability for multiple coils and non-accessibility to intermediate data for research. A novel low-cost multichannel digital receiver for use with MR scanners has been developed to alleviate these concerns. MR signals from up to 16 coils are bandpass sampled at RF, with all...
Some of the most important problems arising during a laparoscopic surgery relate to the limited perception of depth and field of view (fov). In this paper we explore the possibilities of dealing with these problems using appropriate re-modeling of the laparoscopic equipment and image processing algorithms, as to increase the perception ability of the surgeon within the operation space. We demonstrate...
The vascular geometry may play an important role in the development of atherosclerosis by modulating the local hemodynamics and mechanical stresses of the vessel wall. The mouse is now the most popular animal model to study cardiovascular disease. Here, we present a method to characterize the 3-D geometry of mouse aortic arches by casting and light stereo-microscopic imaging. After calibration of...
A method is presented to validate the segmentation of computed tomography (CT) image sequences, and im prove the accuracy and efficiency of the subsequent registration of the 3D surfaces that are reconstructed from the segmented slices. The method compares the shapes of contours extracted from neighborhoods of slices in CT stacks of tibias. The bone is first segmented by an automatic segmentation...
This paper addresses a two-dimensional inverse scattering method with a combination of tomography and radar methods for breast cancer detection. In order to rapidly construct high resolution images displaying the location, size, permittivity and conductivity of malignant tumors inside the body, the collected reflection from the scattered fields present in the scan area is segmented and their associated...
Functional imaging of the human brain using electrical impedance tomography (EIT) is reported, where the measurement data were collected over a period of 308 ms. Initiation of the measurement sequence occurred at times ranging from 70 to 740 ms after administration of visual or auditory stimuli to two volunteers. The reconstructed images of conductivity change due to individual visual stimulus events...
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