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Images which are obtained in clinical radiology are generally evaluated visually. Some information which is available in the images, but not possible to be seen visually can be useful for diagnosis of some diseases. Cyst hydatid which is a parasitic liver disease is still an important health problem in countries where animal breeding is widespread. In this study, we aimed at producing some objective...
It is well known that noise on medical image resulting in low image quality has largely limited the diagnostic usefulness. Therefore, noise reduction for medical images is significantly urgent. However, most reported noise reduction methods, which are usually based on the local statistics of a medical image, are not efficient for medical image noise reduction. This paper presents a novel approach...
One CT exam provides 50-250 times the radiation of a single view x-ray. According to a latest study the chance of getting cancer from x-ray radiation has been increasing by 1.5-2 % at every CT exam. So decreasing the dose per CT exam is a major goal. The aims of this study were to find out how one can improve the signal to noise ratio (S/N) or decrease the dose with the same S/N in mammography CT...
We introduce ultra high speed electron beam tomography as a new imaging tool for multiphase flow measurement and small animal imaging. The technique is based on imaging with X-rays produced by a rapidly scanned electron beam instead of a mechanically rotating source-detector compound. The scanner device ROFEX was developed manufactured and commissioned recently at FZD and allows scanning of objects...
Dynamic fuzzy logic (DFL) is given to solve dynamic fuzzy data problems. Dynamic fuzzy data exists universally, especially in the domain of medical image processing performance evaluation. This paper proposes a new evaluation model for CT medical image de-noising, which is using wavelet transform and dynamic fuzzy logic. Firstly, the CT medical image was decomposed by wavelet transform to obtain the...
The main manifestations of artifacts and their causes in cone-beam computed tomography (CBCT) system were studied, and then the general CBCT digital radiography (DR) imaging model was described with a mathematical expression. On this basis, a new expression of DR imaging model was proposed according to the actual imaging noise and enforceability of corrective action, and so the projection image was...
By analyzing the characters of CT medical image, this paper proposes a novel method for this particular image fusion, which is using discrete wavelet transform and independent component analysis. Firstly, each of CT images were decomposed by 2-D discrete wavelet transform. Then independent component analysis were used to analyse the wavelet coefficients in different level for acquiring independent...
Emerging computed tomographic (CT) imaging modalities such as low dosage imaging and carbon-nano tube imaging impose new challenges for image reconstruction from projections. The limited signal-to-noise ratio and geometry lead to spatial variant artifacts, making it hard for extracting clinical useful information. We present a novel reconstruction method based on the observation that images reconstructed...
Various studies have been conducted to expand the utilization of combined positron emission tomography and computed tomography (PET/CT) covering cases of infection and inflammation. PET images provide the functional activity of a lesion while CT images demonstrate the anatomical location. Hence, existence of infected lesions can be recognized in PET image but since the structural position can not...
Accurate segmentation of bone tissue from Pelvic CT images is an important step in the process of developing an automated computer aided decision making system that would provide physicians with recommendations for the diagnosis and treatment of traumatic pelvic injuries. The proposed algorithm is an automated, unsupervised, and hierarchical method for the segmentation of bone tissue. The method incorporates,...
In this paper, a segmentation method using Gaussian mixture model (GMM) combined with template match is proposed for analysis of brain CT images. The specific aim of this method is to extract ventricles from brain CT images. These can then be used for automated detection of the midline shift in brain. In the method, different types of brain tissue, of which the ventricles form the region of interest,...
The digital image processing techniques, including gray level transformation, image sharpening, image segmentation and edge detection, is applied to the study on the meso-structure image of shale. The results show that the digital image processing technique can extract useful information from the CT images and construct a model of meso-structure of shale. The model shows the spatial distribution of...
Immunoglobulin light chain amyloidosis (AL) is characterized by the deposition of light chain components as insoluble fibrils in tissues and organs leading to dysfunction and death and is the most common form of peripheral amyloid disease in humans. Presently, there are no means available in the USA to image specifically these deposits and thus ascertain the presence or extent of disease. To this...
Two-dimensional computed tomography (CT) images are not enough for further analysis. Only the points with the same Z coordinates can be measured on the two-dimensional images, and the points on the different layers can not be measured. In order to promote the development of the industrial CT, the three-dimensional reconstruction and analysis system is researched in this paper. The three-dimensional...
Variable resolution X-ray (VRX) CT scanners allow imaging of different sized anatomy at the same proportional level of detail using the same device. For example, the same scanner can be used to image large animals such as dogs, and small ones, like mice, with the same level of anatomical detail. This is achieved by tilting the X-ray detectors so that the projected size of the detecting elements is...
An oblique 2D variable resolution x-ray (VRX) detector is a new approach aimed to increase spatial resolution of volumetric CT imaging. The resolution increase results from rotating a 2D planar detector about two axes. In the initial phase of the development of such a detector, the increase in its projection spatial resolution and the side effects of its rotations were analyzed theoretically. The...
Traditional CT reconstructions are limited by many kinds of artifacts, and they give dissatisfactory image. To reduce image noise and artifacts, we propose a statistical iterative method for image reconstruction in cone-beam CT. First the theory of maximum likelihood estimation is extended from emission CT to X-ray scan. Then an expectation-maximization (EM) formula is deduced for direct reconstruction...
Current method of brain perfusion examination using computed tomography (CT) is based on dynamic observation of contrast medium bolus flowing through brain bloodstream at a pre-selected brain layer. Observed area dimension depends on instrument possibilities, amount of contrast medium and radiation dose. This examination produces maps showing values of cerebral blood flow (CBF), cerebral blood volume...
In this paper, an interactive lung parenchyma segmentation algorithm is put forward with improved Live-Wire model, Snake model and contour interpolation, which takes full advantage of lung contours' slow change in adjacent CT image layers and operators' professional knowledge. Firstly, we manually select key slices of lung parenchyma in serial CT images, then draw the lung's contours in key slices...
In this paper problem of airway tree segmentation from CT data sets was regarded. The idea of segmentation using 3D seeded region growing algorithm was introduced. Common problems arising during extracting airway tree from CT data using region growing method were explained. Especially problem of leakage from airway into the lung parenchyma was outlined. Common methods of CT data sets preprocessing...
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