The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
BACKGROUND: Existing methods for quantification of lung ventilation require a tracer gas and specialized imaging such as single photon emission computed tomography (SPECT) or magnetic resonance imaging (MRI). Limitations of these methods include slow imaging speed, complex interpretation, and heavy burden on patients. OBJECTIVE: To assess 3D ventilation quantification based on 4D-CT and multi-resolution...
Conference proceedings front matter may contain various advertisements, welcome messages, committee or program information, and other miscellaneous conference information. This may in some cases also include the cover art, table of contents, copyright statements, title-page or half title-pages, blank pages, venue maps or other general information relating to the conference that was part of the original...
Total variation (TV) minimization problems are widely used for solving incomplete data problems in computed tomography (CT) image reconstruction. The present paper investigates a primal dual proximal point method of Chambolle-Pock algorithm to solve the CT image reconstruction problem which consisting the sum of £2 data fidelity term and TV regularization term. We tested these methods on computer...
Purpose: The positioning accuracy of cancer center is an important factor for radiotherapy effect. The purpose of this study is to investigate the accuracy of patient positioning with Optical Positioning System(OPS) developed by Nanjing University in China, and show its superiority on positioning accuracy, compared with conventional method. Materials and Methods:20 patients with nasopharyngeal carcinoma...
This paper evaluated the performance of two-dimensional (2D) and 3D texture features from CT images on pulmonary nodules diagnosis using the large database LIDC-IDRI. Total of 905 nodules (422 malignant and 483 benign) with certain expert observer ratings of malignancy were extracted from the database based on the radiologists' painting boundaries. Feature analysis on the extracted nodules was not...
Abdominal anatomical structure database is a necessary precondition for medical image computer-aided diagnosis. In this paper, a Web database system based on the CT abdomen anatomy images is established. The system consists of abdominal viscera segmentation and anatomical structure database. Firstly, we need to segment the spleen and liver in abdominal CT images. For spleen segmentation, an improved...
An accurate two-dimensional-three-dimensional (2D-3D) image registration method is introduced in this paper, which is used in image-guided surgery to detect and correct patient movement during image-guided intervention treatment. In this paper, we decompose a 3D rigid transformation in the 3D patient coordinate into in-plane transformations and out-of-plane rotations in two orthogonal 2D projections,...
Ring artifacts are among of the most common artifacts in cone beam computed tomography (CT). High resolution images are often disturbed by these artifacts. In this paper, a ring artifacts reduction method is proposed based on cone beam projection images. CUDA technique is used to accelerate the method. The performance of the proposed algorithm is evaluated using real cone beam CT images. Experiment...
The early degeneration of articular cartilage (AC) is closely related to the change in glycosaminoglycan (GAG) content. The observation of GAG is therefore an appropriate way for evaluating the degree of AC degeneration and diagnosing osteoarthritis. In this study, the method of contrast-agent enhanced Micro-CT, which has been demonstrated as a potential method for quantitatively analyzing the GAG...
A novel, standardized geometric model of the human upper respiratory tract was created by aligning and processing the computed tomography (CT) scans of upper respiratory airway of healthy subjects. Digital three-dimensional (3-D) geometric model of 3 single human upper respiratory airway were generated from the CT scans and a methodology was developed to scale, orient, and align the models, after...
CT-guided interventions have been widely used in lung biopsy procedures to minimize invasion and to improve biopsy accuracy. The basic mathematical statement of the point-based registration problem remains the same in most applications, whereas there are variations on the size and shape of the fiducial markers. In this paper, we measured registration error FLEp and TRE respectively using two types...
The purpose of this paper is to improve the quality of low dose Computed Tomography (CT) images. Low dose artifacts are the Gaussian noises superimposed on the CT images and are often caused by insufficient calibrated detector and photon starvation. A noise reduction method via three dimensionaltotal variation usingCompute Unified Device Architecture (CUDA) is proposed on the three dimensional image...
With spine auxiliary positioning during IGRT treatment, utilize the simulated human phantom and dynamic lung phantom to detect the accuracy of fiducial tracking, and evaluate the value of it. Utilize CT to scan the phantoms which contain films, and design plans for phantoms and spine auxiliary positioning which use 1, 2, 3, 4, 5 and 6 fiducials for tracking, respectively. Each phantom plan shall be...
A fast and robust colorectal polyp detection framework in CT colonography was proposed. In order to speed the detection of polyp in CT colonography, a cascade-Adaboost framework was employed, and a lot of candidates were rejected quickly in the first stages of the cascade framework. To improve the performance of cascade-Adaboost, cascade indifference curve was explored to determine detection rate...
Image feature extraction technology has been widely used in medical field, but there is no related research on image feature extraction of high morbidity of esophageal cancer in Xinjiang. In this paper, feature extraction based on gray-scale histograms was applied in X-ray barium angiogram in high morbidity of esophageal cancer in Xinjiang. For the X-ray barium angiogram, converting RGB image to the...
Objective To investigate the differences of cerebral grey matter atrophy over time between MCI (Mild Cognitive Impairment) and NC (Normal Control), and further investigate the differences of cerebral grey matter atrophy between SMCI (Stable MCI) and PMCI (Progressive MCI). Methods Based on improved VBM-DARTEL method, NC and MCI longitudinal datasets of 3 years were processed. Firstly, the atrophy...
Cone-beam computed tomography (CBCT) is an important technique providing new insights into the inner structure of products in industry and medicine physics. Iterative reconstruction methods have been shown to be more robust than analytical algorithm against the noise and limited angles conditions present in CT. Nevertheless, these methods are not extensively used due to their computational demands...
Despite recent progress in X-ray computed tomography (CT), metal artifact remains to be a major problem in CT image processing and significantly limits numerous important applications. To overcome this problem, a CT image segmentation algorithm using an image multi-scale decomposition model based on the total variation/L1 (TV/L1) model is proposed in this paper. Different metal areas are extracted...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.