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Journal of X-ray Science and Technology

Zhong-Bin Ma, Fang-Qing Ge, Wei-Xia Wang, Zong-Qiong Sun
PURPOSE: To explore the hemodynamic characteristics of variously differentiated breast ductal carcinoma (BDC) using the dynamic contrast-enhanced CT (DCE-CT) based CT perfusion imaging (CTPI), including the specific perfusion parameter values, and to identify potential clinical applications in the cell differentiation degree of BDC. MATERIALS AND METHODS: Forty patients with breast ductal carcinoma confirmed by needle puncture biopsy were studied prospectively using CTPI on a 64-slice spiral CT scanner...
September 3, 2018: Journal of X-ray Science and Technology
Yuanjun Wang, Zeyao Qi
Inspired by the compressed sensing (CS) theory, introducing priori information of sparse image into sparse-view reconstruction algorithm of computed tomography (CT) can improve image quality. In recent years, as a special case of CS, total variation (TV) reconstruction algorithm that uses prior information of both image sparsity and edge direction has attracted much research interest in sparse-view image reconstruction due to its ability to preserve image edges. In this paper, we propose a new adaptive-weight total variation (NAWTV) algorithm for CT image reconstruction, which is derived by considering local gradient direction continuity and the anisotropic edge property...
August 23, 2018: Journal of X-ray Science and Technology
Mohamed S El Tokhy, Imbaby I Mahmoud
Influence of x-ray pulse generated from gamma spectrometers should be eliminated in applications, which typically uses pulse shape techniques between gamma and x-ray pulses. In this study, we proposed and tested several algorithms aiming to eliminate this influence. The algorithms are based on curve fitting (CF), artificial neural network (ANN), system identification, peak shape, amplitude search with curve fitting and pulse tracking methods. Gamma pulses and X-ray pulses are detected by NaI(TI) scintillator detector and Silicon lithium Si(Li) detector, respectively...
August 23, 2018: Journal of X-ray Science and Technology
Kunio Shinohara, Atsushi Ito, Takuji Ohigashi, Masataka Kado, Shigenobu Toné
In this study, soft X-ray spectromicroscopy was applied to investigate and analyze the distribution of DNA and RNA in a mammalian cell at the spatial resolution of 400 nm. The relative distribution of DNA and RNA was examined by the SVD (singular value decomposition) method in aXis2000 program using combined full spectra of DNA and RNA at the absorption edge regions of carbon, nitrogen and oxygen. The absorption of nucleic acid was evaluated using 1s-π* transitions in the NEXAFS spectra at the nitrogen K absorption edge and distributed to DNA and RNA according to the relative level obtained above...
August 21, 2018: Journal of X-ray Science and Technology
Zhengdong Zhou, Runchao Xin, Shaolin Guan, Jianbo Li, Jiali Tu
Development of spectral X-ray computer tomography (CT) equipped with photon counting detector has been recently attracting great research interest. This work aims to improve the quality of spectral X-ray CT image. Maximum a posteriori (MAP) expectation-maximization (EM) algorithm is applied for reconstructing image-based weighting spectral X-ray CT images. A spectral X-ray CT system based on the cadmium zinc telluride photon counting detector and a fat cylinder phantom were simulated. Comparing with the commonly used filtered back projection (FBP) method, the proposed method reduced noise in the final weighting images at 2, 4, 6 and 9 energy bins up to 85...
August 17, 2018: Journal of X-ray Science and Technology
Xiaochuan Wu, Peng He, Yi Zhang, Mianyi Chen, Biao Wei, Fenglin Liu, Kang An, Peng Feng
Material discrimination is an important application of dual-energy computed tomography (CT) techniques. Projection decomposition is a key problem for pre-reconstruction material discrimination. In this study, we focused on the pre-reconstruction space based on the photoelectric and Compton effect decomposition model to characterize different material components, and proposed an efficient method to calculate the projection decomposition coefficient. We converted the complex projection integral into a linear equation by calculating the equivalent monochromatic energy from the high and low energy spectrum...
August 6, 2018: Journal of X-ray Science and Technology
T Arai, C Nagashima, Y Muramatsu, K Murao, I Yamaguchi, N Ushio, K Hanai, M Kaneko
BACKGROUND: The Accreditation Council for Lung Cancer CT Screening of Japan established guidelines for the certification of Radiological Technologists in 2009. OBJECTIVE: To analyze the trends in examination pass rates of the Radiological Technologists and discuss the reasons. METHODS: The cohort comprised 1593 Radiological Technologists (as examinees) based on 10-year of data (with a total of 17 examination runs). First, the examinees' written test results were analyzed...
August 4, 2018: Journal of X-ray Science and Technology
Hang Sun, Hong Li, Shuang Si, Shouliang Qi, Wei Zhang, He Ma, Siqi Liu, Li Yingxue, Wei Qian
OBJECTIVE: Various imaging modalities have been used to diagnose suspicious breast lesions. Purpose of this study is to compare the diagnostic accuracy for breast cancer using mammography, ultrasonography and magnetic resonance imaging (MRI). METHODS: Total 107 patients aged from 19 to 62 years are included in this retrospective study. Mammography, ultrasonography and MRI scans were performed for each patient detected with suspected breast tumor within a month. In addition, the tumor diversity (10 types of benign and 5 types of malignant) was confirmed by pathological findings of tumor biopsy...
July 31, 2018: Journal of X-ray Science and Technology
Ruifeng Wang, Xiaoyi Duan, Cong Shen, Dong Han, Junchao Ma, Wu Hulin, Xiaotong Xu, Tao Qin, Qiuju Fan, Zhaoguo Zhang, Weihua Shi, Youmin Guo
OBJECTIVE: To perform quantitative measurement based on the standardized uptake value (SUV) of Tc-99m methylene diphosphonate (MDP) in the normal pelvis using a single-photon emission tomography (SPECT)/computed tomography (CT) scanner. MATERIAL AND METHODS: This retrospective study was performed on 31 patients with cancer undergoing bone SPECT/CT scans with 99mTc-MDP. SUVmax and SUVmean of the normal pelvis were calculated based on the body weight. SUVmax and SUVmean of the bilateral anterior superior iliac spine, posterior superior iliac spine, facies auricularis ossis ilii, ischial tuberosity, and sacrum were also calculated...
July 31, 2018: Journal of X-ray Science and Technology
Tomasz Kowaluk, Adam Wozniak
The article presents and discusses results of an experimental study regarding the accuracy of measurements performed with X-ray CT scanners. One of the main factors affecting the measurement result is definition of the threshold value between the air and the material. In this study, the results of measurements using two methods to determine the threshold value namely, the newly developed method and a well-known and commonly used method of ISO50%, were compared. A novel method is based on the measurement of an additional reference workpiece...
July 23, 2018: Journal of X-ray Science and Technology
Dildar Hussain, A Mugahed Al-Antari, A Mohammed Al-Masni, Seung-Moo Han, Tae-Seong Kim
BACKGROUND: Accurate measurement of bone mineral density (BMD) in dual-energy X-ray absorptiometry (DXA) is essential for proper diagnosis of osteoporosis. Calculation of BMD requires precise bone segmentation and subtraction of soft tissue absorption. Femur segmentation remains a challenge as many existing methods fail to correctly distinguish femur from soft tissue. Reasons for this failure include low contrast and noise in DXA images, bone shape variability, and inconsistent X-ray beam penetration and attenuation, which cause shadowing effects and person-to-person variation...
July 23, 2018: Journal of X-ray Science and Technology
Wei Chen, Xiang-Ming Fang, Xuan Wang, Sanjeev Kumar Pitla Sudarshan, Xiao-Yun Hu, Hong-Wei Chen
PURPOSE: To evaluate the clinical efficacy of percutaneous trans-hepatic integrated 125I seed stents implantation for malignant lower biliary tract obstruction. METHODS: Thirty-two patients with malignant lower biliary obstruction were randomly divided into two groups. One group underwent the therapy with integrated 125I seed stents (Test group, n = 13), and another group received conventional metal stents implantation for treatment (Control group, n = 19). The pre- and post-operative changes in biochemical indices, white blood cell count, IgG level, stent patency, survival time, tumor size and complications were compared between the two groups...
July 19, 2018: Journal of X-ray Science and Technology
Qian Wang, Kriti Sen Sharma, Hengyong Yu
BACKGROUND: In clinical computed tomography (CT) applications, when a patient is obese or improperly positioned, the final tomographic scan is often partially truncated. Images directly reconstructed by the conventional reconstruction algorithms suffer from severe cupping and direct current bias artifacts. Moreover, the current methods for projection extension have limitations that preclude incorporation from clinical workflows, such as prohibitive computational time for iterative reconstruction, extra radiation dose, hardware modification, etc...
July 18, 2018: Journal of X-ray Science and Technology
Jia Zheng, Dinghua Zhang, Kuidong Huang, Yuanxi Sun
BACKGROUND: Images of industrial cone-beam computed tomography (CBCT) contain noise and beam hardening artifacts, which induce difficulty and low precision in segmenting regions of interest. OBJECTIVE: The primary objective of this study is to improve the segmentation precision of CBCT series slice images. METHODS: This paper presents a method based on the Phansalkar to segment CBCT series slice images precisely. First, the basics of the proposed method and the necessity of changing the local window size are analysed...
July 18, 2018: Journal of X-ray Science and Technology
Young-Pyo Kim, Yong-Pil Park, Min-Woo Cheon
Mobile X-ray device is widely employed because it is useful for diagnosis in patients having mobility difficulties and in medical emergencies. As various devices for X-ray generation have continued to be developed, X-ray devices can now be used more safely and effectively. However, mobile X-ray devices generate relatively low X-ray doses due to the limitation of the power input. Therefore, the use of mobile X-ray devices is limited to thin parts of body. In this study, a new device was designed in order to increase the usefulness of mobile X-ray devices by offsetting the weaknesses of the existing mobile X-ray devices, rendering them useable independently...
July 6, 2018: Journal of X-ray Science and Technology
Matthew Getzin, Josephine J Garfield, David S Rundle, Uwe Kruger, Anthony P H Butler, Manos Gkikas, Ge Wang
BACKGROUND: X-ray CT/micro-CT methods with photon-counting detectors (PCDs) and high Z materials are a hot research topic. One method using PCDs allows for spectral imaging in 5 energy windows while conventional X-ray detectors only collect energy-integrating data. OBJECTIVE: To demonstrate the enhanced separation of contrast materials by using PCDs, multivariate analysis, and linear discriminant methods. METHODS: Phantoms containing iodine and aqueous nanomaterials were scanned on a MARS spectral micro-CT...
July 4, 2018: Journal of X-ray Science and Technology
Jie Li, Wenkun Zhang, Ailong Cai, Linyuan Wang, Ningning Liang, Zhizhong Zheng, Lei Li, Bin Yan
Since the excessive radiation dose may induce potential body lesion, the low-dose computed tomography (LDCT) is widely applied for clinical diagnosis and treatment. However, the dose reduction will inevitably cause severe noise and degrade image quality. Most state-of-the-art methods utilize a pre-determined regularizer to account for the prior images, which may be insufficient for the most images acquired in the clinical practice. This study proposed and investigated a joint regularization method combining a data-driven tight frame and total variation (DDTF-TV) to solve this problem...
July 4, 2018: Journal of X-ray Science and Technology
Liping Zhan, Runtao Gao, Jiao Fan, Huarui Ma
OBJECTIVE: This study aims to evaluate the effect of dentoalveolar distraction extraction (DDE) on site preservation, and to evaluate how the technique keeps the height and width of alveolar bones to a greater extent. METHODS: 12 beagle dogs, randomly divided into three groups (DDE group, NH group, BOG group), were used. In the dogs of three groups, the distal root of the left or right third mandibular premolars were respectively extracted by three methods namely, DDE, traditional extraction with natural healing, and traditional extraction with Bio-Oss bone dust implanted and guided bone regeneration (GBR)...
June 29, 2018: Journal of X-ray Science and Technology
Tsukasa Nakano, Yoshito Nakashima
BACKGROUND: Cylindrical phantoms are often imaged by X-ray computed tomography (CT) to evaluate the extent of beam hardening (or cupping artifact) resulting from a polychromatic X-ray source. OBJECTIVE: Our goal was to derive analytical expressions for the reconstructed image of a homogeneous cylindrical phantom exhibiting a cupping artifact, to permit a quantitative comparison with experimental cupping data. METHODS: A filtered backprojection method was employed to obtain the analytical cupping profile for the phantom, assuming that the projection data could be approximated as a power series with respect to the sample penetration thickness...
June 29, 2018: Journal of X-ray Science and Technology
Neslihan Kurtul, Nursel Yurttutan, Murat Baykara
OBJECTIVE: The aim of this study was to apply texture analysis to investigate whether there was a change in the lens following radiotherapy. PATIENTS AND METHOD: Patients who received radiotherapy (RT) for head and neck cancer or brain tumour were enrolled. Computed tomography (CT) images taken one month before RT and the most recent images after RT were compared. Entropy values were calculated using lens attenuation values. The lens doses were obtained from the dose-volume histogram data...
June 5, 2018: Journal of X-ray Science and Technology
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