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Journal of X-ray Science and Technology

Liang Xu, Rongchang Chen, Yiming Yang, Biao Deng, Guohao Du, Honglan Xie, Tiqiao Xiao
Monochromatic-beam-based dynamic X-ray computed microtomography (CT) was developed to observe evolution of microstructure inside samples. However, the low flux density results in low efficiency in data collection. To increase efficiency, reducing the number of projections should be a practical solution. However, it has disadvantages of low image reconstruction quality using the traditional filtered back projection (FBP) algorithm. In this study, an iterative reconstruction method using an ordered subset expectation maximization-total variation (OSEM-TV) algorithm was employed to address and solve this problem...
July 31, 2017: Journal of X-ray Science and Technology
Mengfei Li, Yunsong Zhao, Peng Zhang
Computed tomography (CT) plays an important role in digital rock analysis, which is a new prospective technique for oil and gas industry. But the artifacts in CT images will influence the accuracy of the digital rock model. In this study, we proposed and demonstrated a novel method to restore detector-unit-dependent functions for polychromatic projection calibration by scanning some simple shaped reference samples. As long as the attenuation coefficients of the reference samples are similar to the scanned object, the size or position is not needed to be exactly known...
July 31, 2017: Journal of X-ray Science and Technology
Xia Liu, Liansheng Liu, Fen Hou, Zhifeng Zhou, Qingying Wu, Hengguo Li
BACKGROUND: Motor learning and professional sports training can induce plastic changes in brain structures that are associated with distinct training demands. OBJECTIVE: To testify the hypothesis of that regional gray matter structures in the motor-related cortex and its functional connectivity (FC) are altered in young divers. METHODS: We undertook T1-voxel-based morphometry (VBM) structural and resting-state functional magnetic resonance imaging in groups of diving athletes (DAs) and demographically-matched healthy controls...
July 7, 2017: Journal of X-ray Science and Technology
Shurong Han, Yeqing Huang
The study analysed the medical imaging technology business cycle from 1981 to 2009 and found that the volatility of consumption in Chinese medical imaging business was higher than that of the developed countries. The volatility of gross domestic product (GDP) and the correlation between consumption and GDP is also higher than that of the developed countries. Prior to the early 1990s the volatility of consumption is even higher than GDP. This fact makes it difficult to explain the volatile market using the standard one sector real economic cycle (REC) model...
July 7, 2017: Journal of X-ray Science and Technology
Zong-Qiong Sun, Gen Yan, Yu-Xi Ge, Jie Li, Lin-Fang Jin, Zhi-Hui Xie, Peng Zhao
PURPOSE: To explore the value of low-dose CT perfusion imaging (LDCTPI) technology and its perfusion parameters in assessing response of neoadjuvant chemotherapy (NAC) in patients with advanced gastric cancer (AGC). METHODS: Thirty patients with AGC were studied prospectively by LDCTPI to measure two parameters including blood flow (BF) and blood volume (BV) of tumor area before and after chemotherapy, respectively. All of the patients received two courses of NAC and surgical resection of gastric tumor within one week after chemotherapy, and then obtained the result of postoperative pathology response for chemotherapy...
July 7, 2017: Journal of X-ray Science and Technology
Ti Bai, Hao Yan, Luo Ouyang, David Staub, Jing Wang, Xun Jia, Steve B Jiang, Xuanqin Mou
BACKGROUND: In regularized iterative reconstruction algorithms, the selection of regularization parameter depends on the noise level of cone beam projection data. OBJECTIVE: Our aim is to propose an algorithm to estimate the noise level of cone beam projection data. METHODS: We first derived the data correlation of cone beam projection data in the Fourier domain, based on which, the signal and the noise were decoupled. Then the noise was extracted and averaged for estimation...
July 7, 2017: Journal of X-ray Science and Technology
Min Jiang, Yi Sun, Zhiping Qu, Mengjie Li
Sparse-view Computed Tomography (CT) plays an important role in industrial inspection and medical diagnosis. However, the established reconstruction equations based on traditional Radon transform are ill-posed and obtain an approximate solution in the case of finite sampling angles. By contrast, Mojette transform is considered as the discrete geometry of the projection and reconstruction lattice. It determines the geometrical conditions for ensuring a unique solution instead of solving an ill-posed problem from the start...
July 7, 2017: Journal of X-ray Science and Technology
Zhizhong Zheng, Ailong Cai, Lei Li, Bin Yan, Fulong Le, Linyuan Wang, Guoen Hu
Sparse-view imaging is a promising scanning approach which has fast scanning rate and low-radiation dose in X-ray computed tomography (CT). Conventional L1-norm based total variation (TV) has been widely used in image reconstruction since the advent of compressive sensing theory. However, with only the first order information of the image used, the TV often generates dissatisfactory image for some applications. As is widely known, image curvature is among the most important second order features of images and can potentially be applied in image reconstruction for quality improvement...
July 7, 2017: Journal of X-ray Science and Technology
Lin Li, Yong Wang, De-Hong Luo, Yan-Feng Zhao, Meng Lin, Wei Guo, Lei Hu, Chun-Wu Zhou, Xin-Ming Zhao
BACKGROUND: Ultrasound (US) and computed tomography (CT) are common diagnostic imaging methods for detecting and diagnosing papillary thyroid microcarcinoma (PTMC). However, single-source dual-energy spectral computed tomography (spectral CT) reduces beam hardening artefacts and optimizes contrast, which may add value in detecting PTMC. OBJECTIVE: To investigate values of applying single-source dual-energy spectral CT for diagnosing PTMCs, in comparison with high frequency ultrasound and conventional polychromatic images...
June 10, 2017: Journal of X-ray Science and Technology
Zong-Qiong Sun, Yu-Xi Ge, Lin Chen, Jie Li, Lin-Fang Jin, Zhi-Hui Xie
PURPOSE: To investigate feasibility of applying low-dose CT perfusion imaging (CTPI) to diagnose gastric cancer. MATERIALS AND METHODS: Twenty patients with gastric cancer confirmed by endoscopic biopsy were undergone routine dose (120 kV, 100 mA) and low-dose (120 kV, 50 mA) CTPI examination, respectively. The original data were processed by body perfusion software, and the perfusion parameters values including blood flow (BF), blood volume (BV) and permeability surface (PS) of gastric cancer were measured...
June 3, 2017: Journal of X-ray Science and Technology
Wei Zhang, Dianwen Zhu, Michael Lun, Changqing Li
X-ray luminescence computed tomography (XLCT) is a hybrid imaging modality with the potential to achieve a spatial resolution up to several hundred micrometers for targets embedded in turbid media with a depth larger than several millimeters. In this paper, we report a high spatial resolution XLCT imaging system with a collimated superfine x-ray beam in imaging the deeply embedded targets. A collimator with a 100 micrometer pinhole was mounted in the front of a powerful x-ray tube to generate a superfine x-ray pencil beam with a beam diameter of 0...
June 3, 2017: Journal of X-ray Science and Technology
Jawook Gu, Woong Bae, Jong Chul Ye
BACKGROUND: Cone-beam computed tomography (CBCT) is widely used in various medical imaging applications, including dental examinations. Dental CBCT images often suffer from motion artifacts caused by involuntary rigid motion of patients. However, earlier motion compensation studies are not applicable for dental CBCT systems using truncated detectors. OBJECTIVE: This study proposes a novel motion correction algorithm that can be applied for truncated dental CBCT images...
June 3, 2017: Journal of X-ray Science and Technology
Hewei Gao, Lei Zhu, Rebecca Fahrig
A new scatter estimation algorithm with a concept of virtual scatter modulation for X-ray scatter correction using primary modulator is proposed to reduce the aliasing errors in the estimated scatter. Virtual scatter modulation can be realized through dividing the measured primary-modulated image by the measured modulation function. After the division, the aggravation of the aliasing of primary due to the non-uniformity of the modulation function is largely transferred to that of scatter. Since scatter in general has less high frequencies than primary does, the aggravation of its aliasing is expected to be weaker, and therefore the overall aliasing can be reduced...
May 31, 2017: Journal of X-ray Science and Technology
Lei Song, Jungang Gao, Sheng Wang, Youmin Guo
Estimation of the pleural effusion's volume is an important clinical issue. The existing methods cannot assess it accurately when there is large volume of liquid in the pleural cavity and/or the patient has some other disease (e.g. pneumonia). In order to help solve this issue, the objective of this study is to develop and test a novel algorithm using B-spline and local clustering level set method jointly, namely BLL. The BLL algorithm was applied to a dataset involving 27 pleural effusions detected on chest CT examination of 18 adult patients with the presence of free pleural effusion...
May 24, 2017: Journal of X-ray Science and Technology
A Salar Elahi, M Ghoranneviss
Plasma cooling due to hard x-ray radiation from the Runaway electrons is an important issue in tokamaks. Thus, developing effective methods to reduce the Runaway electrons and the emitted hard x-ray is also important for optimal tokamak plasma operation. In this study, we investigated the effects of external fields on hard x-ray intensity and the Magnetohydrodynamic (MHD) activity. In other words, we presented the effects of positive biased limiter and Resonant Helical Field (RHF) on the MHD fluctuations and hard x-ray emission from the Runaway electrons...
May 24, 2017: Journal of X-ray Science and Technology
Wanli Lu, Lei Li, Ailong Cai, Hanming Zhang, Linyuan Wang, Bin Yan
Iterative reconstruction algorithms for computed tomography (CT) through total variation (TV) regularization can provide accurate and stable reconstruction results. TV minimization is the L1-norm of gradient-magnitude images and can be regarded as a convex relaxation method to replace the L0 norm. In this study, a fast and efficient algorithm, which is named a weighted difference of L1 and L2 (L1 - αL2) on the gradient minimization, was proposed and investigated. The new algorithm provides a better description of sparsity for the optimization-based algorithms than TV minimization algorithms...
May 15, 2017: Journal of X-ray Science and Technology
Xianfeng Xu, Zhenzhou Li, Jin Liu, Sha Yu, Zhaolian Wei
OBJECTIVE: To investigate the microRNA expression profiling in endometriosis-associate infertility, and relationship between the microRNA expression and endometrial receptivity evaluated by ultrasound. METHODS: First, miRNA expression profiling difference of ectopic endometrium between 8 endometriosis patients and 6 endometriosis-free patients were compared. Bioinformatics analyses detected 61 differentially expressed (DE) known miRNAs and 57 DE novel miRNAs. Next, other 24 patients were selected for checking the microRNAs in differential expression by RT-PCR...
May 6, 2017: Journal of X-ray Science and Technology
Norio Hayashi, Kazuma Yarita, Kozue Sakata, Shunichi Motegi, Hiroyuki Nagase, Kouichi Ujita, Akio Ogura, Toshihiro Ogura, Takehiro Shimada, Yoshito Tsushima
BACKGROUND: Optimizing scan parameters for double inversion recovery (DIR) sequences remains difficult. OBJECTIVE: To evaluate a new method for optimizing DIR sequence scan parameters using T1 mapping and a newly developed analysis algorithm. METHODS: Twelve healthy volunteers underwent T1 mapping and DIR magnetic resonance imaging. The following steps were used for image optimization including: 1) measurement of gray matter (GM), white matter (WM), and cerebrospinal fluid (CSF) T1 values to create a T1 map; 2) calculation of optimized scan parameters by using a developed analysis algorithm; 3) performance assessment of DIR magnetic resonance imaging by using the calculated optimized imaging parameters...
May 6, 2017: Journal of X-ray Science and Technology
Xia Li, Hua Xin, Shifeng Yang, Miaoqing Zhao, Ximing Wang, Nan Zhang
Osteoblastoma is a rare benign primary bone tumor, which occurs in any part of the skeleton. Extraskeletal osteoblastoma is rather rare. We presented an extremely rare case of extraskeletal osteoblastoma located in the breast. The tumor recurred 7 months later after resection and transformed to aggressive osteoblastoma. The histopathological features, ultrasonic manifestations and ultrasonic differential diagnoses of the primary and recurrent tumors were discussed. The recommended treatment of the tumor is surgical excision...
May 6, 2017: Journal of X-ray Science and Technology
Mehran Yazdi, Zohre Mansourian
Objective of this study is to present and test a new method for metal artifact reduction (MAR) by segmenting raw CT data (sinogram). The artifact suppression technique incorporates two steps namely, metal projection segmentation in the sinogram and replacement of segmented regions by new values using an interpolation method. The proposed segmentation algorithm uses the sinogram instead of reconstructed CT slices. First, one of the best and newest region-based geometric active contour models is used to detect projection data affected by metal objects (missing projections)...
May 6, 2017: Journal of X-ray Science and Technology
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