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Purpose:To investigate the feasibility of utilizing texture features to classify nodule from normal thyroid tissue in Computed Tomography (CT) images. Materials and Methods: Group A (negative) includes 152 normal thyroid CT images from 55 patients healthy controls enrolled in the study. Group B (positive) includes 134 thyroid images with nodules (50 malignant, 84 benign) of 58 patients undergone thyroid...
Computer aided diagnosis (CAD) has been important more than ever for accurate diagnosis of liver tumors. The paper presents a novel image representation method for classifying normal livers and livers with tumors. It starts by capturing region of interesting (ROI) for individual livers, on which patches are extracted densely. Histogram of oriented gradients (HOG) and intensity are then extracted as...
Detection of implanted iodine-125 seeds in postoperative CT is a necessary step for evaluating the output of seed implantation brachytherapy of lung tumor. In this paper, we propose a semi-automated method to detect implanted seeds in postoperative lung CT. Three main steps are included in our approach. Firstly, the ROI (Region Of Interest) containing all seeds is extracted from the original image...
Efficiently obtaining a reliable coronary artery centerline from computed tomography coronary angiography (CTCA) data is relevant in clinical practice. In this paper, open-snake is presented to extract the vessel centerline, which is drove by two external forces, one is Gradient Vector Flow (GVF), and the other one is an adaptive stretching force acted on the two ends of open-snake. To make the open-snake...
As a common CT image quality (IQ) test phantom, Catphan500 is widely used for the verification tests in Chinese metrology institutes as well as hospital routine quality assurance (QA). Although the National Verification Regulation of Medical Diagnostic X-ray Radiation Source for Spiral CT (JJG 1026-2007) had been issued and carried out for years in China, however, main parameters such as image uniformity,...
In the recent years, reconstructing 3D liver and its vessels from abdominal CT volume images becomes an inevitable and necessary research field. In this paper, a method of 3D reconstruction of liver with its vessels has been implemented, which involves volume preprocessing, de-noising, segmentation, contouring, and combination of different modalities. An advanced liver segmentation algorithms have...
The constrained total variation minimization has been developed successfully for image reconstruction in computerized tomography. The convergence of the block cyclic projection and Cimmino algorithms for compressed sensing based tomography have been proved recently. In this paper, a block component averaging algorithm incorporation to the total variation minimization in the compressed sensing framework...
In this paper, we propose a block diagonally-relaxed orthogonal projection algorithm incorporated into the total variation minimization for computed tomography image reconstruction in the compressed sensing framework and derive its convergence. A numerical experiment is performed to illustrate the convergence of the new algorithm.
For lung tissue adhesion of the situation in the lung CT images, based on the classical watershed algorithm, this introduce line-encoded ideology, use contour tracing method to determine adhesion region segmentation points, according to segment code to get the split line, thus separating the adhesion region. Experimental results show that this method will be effective in the lung adhesion region segmentation,...
We present a new frame of lung parenchyma segmentation. Optimal threshold value method and the boundary tracking method are used to get rid of the background interference and segment the lung region. Then new algorithm is used for lung region boundary repairing based on the mathematical morphology method. The experimental results show the new algorithm can segment lung regions from the chest CT images...
In this work, we investigate the performances of segmentation algorithms applied to micro-CT images of small animal to derive anatomical templates for guided Fluorescence Molecular Tomography. We report on the performances of Active Contours methods to retrieve the boundary surface of the specimen and the internal distribution of a fluorescent probe. The spatial information gained from this segmentation...
In order to analyze stress of the part in service, a flow for stress analysis of the part in service is proposed based on industrial computed tomography(CT). Firstly, the part in service was scanned to get CT image which was processed to extract the edge by Canny method. Then the edge was transformed into vector graph. Finally, the vector graph was analyzed by finite element method based on simulating...
Most of cable saddle test and theoretical study about extradosed bridge consider that the normal force on arc wall of embedded pipe is evenly distributed. The approximate load simulation will affect the accuracy of analytical results. Referring to the typical cable saddle structure of extradosed bridge, a polyurethane model was produced for this paper. Through a series of CT scan experiment, we obtained...
Osteoporotic patients occur frequently fragile fractures, and femoral fractures are the common traumatic injuries in the elderly. Although wires are often used through trials-and-errors for unstable femoral proximal fractures with DHS fixation clinically, there is no efficacy wire fixation technique available due to the lack of biomechanical study. FEM is applied to analyze the stress and strain distribution...
Photon counting x-ray detectors (PCD) promise to provide substantial improvements in computed tomography (CT) as compared to Cesium Iodide based energy integrating x-ray detectors (CsI-EID). This paper investigates the possible improvements in signal-to-noise ratio (SNR) obtained by using a cadmium zinc telluride (CZT) crystal based PCD with energy weighting (EW) in low dose breast CT (BCT).
This work describes a protocol for creating a population of pediatric, patient specific, computational dosimetry phantoms. Pediatric CT data are mapped to a detailed adult template using multi channel (MC) - large deformation diffeomorphic metric mapping (LDDMM) applied to whole body images. Challenges are studied and overcome using 2D LDDMM applied to simulated phantoms. The protocol involves automatic...
The purpose of this study was to characterize the effects of cyclic mechanical loading at different frequencies on the intervertebral disc and vertebral endplates. Static, 0.5 Hz or 5 Hz loading at 5 × BW was applied to the rabbit lumbar spine in vivo 2 hours/day, 5 days/week for up to 30 weeks. Following the loading period, MRI, μCT and histology analyses were performed. Results indicate an increase...
Non-enzymatic glycation (NEG) detrimentally affects cancellous bone's mechanical integrity. In particular, it may help explain the fragility of osteoporotic bone, which is composed primarily of thinner and more rod-like trabeculae. Hence, the goal of our project was to investigate the relationship between the extent of NEG and trabecular morphology. Individual trabeculae were extracted from mechanically...
Computed tomography (CT) requires high-speed detector with wide dynamic range (WDR) and high linearity. CMOS CT detectors have been demonstrated with WDR and quantum-limited noise. However, existing CMOS CT detectors have low linearity, which cause artifacts during the image reconstruction. They also require high-resolution off-chip analog-to-digital converter (ADC) to quantize the WDR. In this work,...
Osteoporosis has been widely known as a reoccurring issue with the increase of age. By understanding key mechanical properties of bone, researchers can better understand methods to induce bone growth as a possible method for osteoporosis reversal. This study uses image modeling to characterize the natural frequency of normal bone by using Finite Element Methods (FEM). Results indicate that the natural...
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