Current Issue : April - June Volume : 2018 Issue Number : 2 Articles : 5 Articles
This paper presents amultitasking electrical impedance tomography (EIT) system designed to improve the flexibility and durability\nof an existing EIT system. The ability of the present EIT system to detect, locate, and reshape objects was evaluated by four different\nexperiments. The results of the study show that the system can detect and locate an object with a diameter as small as 1.5mm in a\ntesting tank with a diameter of 134 mm.Moreover, the results demonstrate the ability of the current system to reconstruct an image\nof several dielectric object shapes. Based on the results of the experiments, the programmable EIT system can adapt the EIT system\nfor different applications without the need to implement a new EIT system, which may help to save time and cost. The setup for all\nthe experiments consisted of a testing tank with an attached 16-electrode array made of titanium alloy grade 2. The titanium alloy\nelectrode was used to enhance EIT system�s durability and lifespan....
Purpose. To performlung image registration for reducing misregistration artifacts on three-dimensional (3D) temporal subtraction\nof chest computed tomography (CT) images, in order to enhance temporal changes in lung lesions and evaluate these changes after\ndeformable image registration (DIR). Methods. In 10 cases, mutual information (MI) lung mask affine mapping combined with\ncross-correlation (CC) lung diffeomorphicmapping was used to implement lung volume registration.With advanced normalization\ntools (ANTs), we used greedy symmetric normalization (greedy SyN) as a transformation model, which involved MI-CC-SyN\nimplementation. The resulting displacement fields were applied to warp the previous (moving) image, which was subsequently\nsubtracted from the current (fixed) image to obtain the lung subtraction image. Results. The average minimum and maximum\nlog-Jacobians were 0.31 and 3.74, respectively.When considering 3D landmark distance, the root-mean-square error changed from\nan average of 20.82mm for ...
This paper describesamethod based onanautomatic segmentation process to coregister carpal bones of the same patient imaged at\ndifferent time points. A rigid registration was chosen to avoid artificial bone deformations and to allow finding eventual differences\nin the bone shape due to erosion, disease regression, or other eventual pathological signs. The actual registration step is performed\non the basis of principal inertial axes of each carpal bone volume, as estimated from the inertia matrix. In contrast to already\npublished approaches, the proposed method suggests splitting the 3D rotation into successive rotations about one axis at a time\n(the so-called basic or elemental rotations). In such a way, singularity and ambiguity drawbacks affecting other classical methods,\nfor instance, the Euler angles method, are addressed.The proposed method was quantitatively evaluated using a set of real magnetic\nresonance imaging (MRI) sequences acquired at two different times from healthy wrists and by choosing a direct volumetric\ncomparison as a cost function. Both the segmentation and registration steps are not based on a priori models, and they are therefore\nable to obtain good results even in pathological cases, as proven by the visual evaluation of actual pathological cases...
A polychromatic X-ray beam causes the grey of the reconstructed image to depend on its position within a solid and the material\nbeing imaged. This factor makes quantitative measurements via computed tomography (CT) imaging very difficult. To obtain\na narrow-energy-width reconstructed image, we propose a model to decompose multivoltage X-ray images into many narrowenergy-\nwidth X-ray images by utilizing the low frequency characteristics of X-ray scattering. It needs no change of hardware in the\ntypicalCTsystem. Solving the decompositionmodel, narrow-energy-width projections are obtained and it is used to reconstruct the\nimage. A cylinder composed of aluminum and silicon is used in a verification experiment. Some of the reconstructed images could\nbe regarded as real narrow-energy-width reconstructed images, which demonstrates the effectiveness of the proposed method....
Stomach bleeding is a kind of gastrointestinal disease which can be diagnosed noninvasively by wireless capsule endoscopy (WCE).\nHowever, it requires much time for physicians to scan large amount of WCE images. Alternatively, computer-assisted bleeding\nlocalization systems are developed where color, edge, and intensity features are defined to distinguish lesions from normal tissues.\nThis paper proposes a saliency-based localization system where three saliency maps are computed: phase congruency-based edge\nsaliency map derived from Log-Gabor filter bands, intensity histogram-guided intensity saliency map, and red proportion-based\nsaliency map. Fusing the three maps together, the proposed system can detect bleeding regions by thresholding the fused saliency\nmap. Results demonstrate the accuracy of 98.97% for our system to mark bleeding regions....
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