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We developed a 3D tomographic non-destructive test detecting fluorescence X-rays with a 2D CdTe array. Experiments proceeded with various phantoms and image reconstruction methods. In general, conventional Computed Tomography (CT) analyzes materials based on attenuation coefficients and is highly dependent on the densities of the materials, and hence, it is difficult to discriminate similar density...
In this work, a mask-enhanced dual-dictionary learning method is proposed to solve the problem of hybrid image reconstruction in magnetic resonance imaging (MRI) and X-ray computed tomography (CT). One dictionary trained from MRI data as a high quality dictionary used to generate a base MRI, and the other dictionary trained from CT data as a low quality dictionary to get the sparse representation...
Conventional CPU-based algorithms for Computed Tomography reconstruction lack the computational efficiency necessary to process large, industrial datasets in a reasonable amount of time. Specifically, processing time for a single-pass, trillion volumetric pixel (voxel) reconstruction requires months to reconstruct using a high performance CPU-based workstation. An optimized, single workstation multi-GPU...
Dynamic contrast enhanced CT can be used to measure perfusion, thus enabling a quantitative assessment of vascular integrity. Conventional dynamic CT involves the reconstruction of dynamic sequences of 3D images from complete projections acquired at relatively short time intervals. This approach is suitable for spiral scanners but it is unfeasible for most of small-animal cone-beam scanners, as the...
A precise knowledge of the geometry is always pivotal to a x-ray imaging system, such as computed tomography, digital x-ray tomosynthesis and computed laminography. A typical tomosynthesis system is referred to as the relative positions between the focal spots of the x-ray source and the detector, the object remains in a fixed position above the detector and the x-ray tube emits x-ray beams in the...
The authors have previously shown that electrical trees in unfilled polymers can be three-dimensionally (3D) imaged using X-ray computed tomography (XCT) or serial block-face scanning electron microscopy (SBFSEM). Here, we present the results of 3D imaging and analysis of electrical trees in filled epoxy systems for the first time. Electrical trees created in unfilled, micro silica-filled and nano...
In this paper, the micro-structure of the Shangjuxu acupuncture point or tissue where there were no acupoints in the fractional rabbit hind limb were studied by in-line phase contrast CT imaging (IL-XPCI-CT) methods based on synchrotron radiation. Then the imaging results are reconstructed in three-dimensional limit, and the 3D images for different tissues are compared. The experiments were performed...
The objective of this article is to discuss the clinical application values of multi-slice CT (MSCT) and image post-processing technique in the diagnosis of occult rib fracture. Method: after chest X-ray, 40 cases of chest trauma patients done 16 layers spiral CT scan, and the data from 16 layers spiral CT would be via the workstation to do multiple planar reconstruction (MPR) and volume reconstruction...
Computed Tomography (CT) is one of the most used imaging techniques in medical field which enables us to generate two-dimensional as well as three-dimensional image of the inside the body. Fundamentally, any imaging system contains two main stages the data collection and the image reconstruction. For CT, The data collection stage depends on the resolution of image collected and field of view. The...
The aim of this work is to present a 3D reconstruction method of the proximal femur shape using contours identification from pairs of 2D X-ray radiographs without any prior acknowledge. 3D personalized model was reconstructed following a processing chain of seven different steps. After localization of the 2D contours on the images and the matching points of these contours, a 3D contour is generated...
Root is an important organ for plant to uptake nutrient and water from the surrounding soil. And the capability of plant to obtain nutrient and water is closely relevant to its root distribution and architecture under ground. Soil is the source of water and nutrients for plant; however, it also obstructs the observation and measurement of the root system. A thorough investigation of root morphology...
Time domain THz spectroscopy and 3D imaging are used for non-destructive analyses of modern pottery which was made using ancient and traditional technology. Our study demonstrates that the internal structure of this of Pre-Columbian civilizations Mochica type pottery can be revealed with the help of X-Ray images used as references.
This paper is on reduction of x-ray radiation dosage in computerized tomography (CT) examinations without compromising the image quality by compressed sensing (CS). For this purpose, the smoothness of the sinogram data set and the sparsity of its frequency transformation are exploited which, in corporation with a randomly projected x-ray radiation scheme, can result in a randomly undersampled partial...
The industry is going through a transition in material sets for second level interconnects including adoption of leadfree solders. High-rel systems may often have a mix of components with different solder alloys in the printed circuit assemblies including both leaded and leadfree solders because some original leaded components may only be available in leadfree configurations. In this paper, the potential...
With distributed sources along a helix trajectory, the helical interlaced source detector array (HISDA) requires no rotation while scanning, thus improving temporal resolution and ensuring mechanical stability. However, in this system, gaps exist in the detector array where sources are placed, resulting in the non-measurement of projection data in gaps. To solve this problem, we propose the semi-stationary...
Low-dose x-ray computed tomography (CT) scan is clinically desired. However, the quality of low-dose CT image is severely degraded due to excessive photon quantum noise and electronic noise. To improve the quality of CT image with lower milliampere-seconds (mAs), in this study, we developed an iterative image reconstruction algorithm based on the maximum a posterior (MAP) principle. To preserve the...
High radiation dose during x-ray computed tomography (CT) examinations can increase the risk of cancer and has become major concerns to patient. Accordingly, minimizing the radiation exposure without sacrificing image quality is a meaningful research topic. In this work, with the aim to reduce radiation during data acquisition, we propose a penalized weighted least-squares (PWLS) scheme to retain...
Nanophosphors emit near-infrared (NIR) light upon x-ray excitation, and can be functionalized as optical probes for in vivo molecular imaging. X-ray luminescence computed tomography (XLCT) combines the high sensitivity optical imaging with the high spatial resolution x-ray imaging to visualize specific molecular and cellular targets, pathways and therapeutic responses. In this paper, we propose an...
We previously discussed “omni-tomography”, but intrinsic conflicts between the magnetic fields of the MRI and the x-ray tube within the CT are inherent. We propose that by using low-field MRI with a negligible fringe field at the site of the CT source, it is possible to create a CT-MRI system with minimal interference. Low field MRI is particularly useful for lung imaging, where hyperpolarized gas...
Image recovery from undersampled data has always been a challenging and fascinating task due to its implicit ill-posed nature and significance accompanied with the emerging compressed sensing (CS) theory. This paper proposes a novel Gradient based Dictionary Learning method for CT image Reconstruction (GradDL-CT), which alleviates the drawback of the popular total variation (TV) regularization by...
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