bluuebunny/crossref_metadata_2025 huggingface dataset:
Wavelet Decomposition Based Audio Feature Extraction Method for Distributed Fiber Optic Audio of Belt Conveyor
Authors: Zhu Shengqiang , Liu Cong , Qian Ke
Published: November 2024

The operation status of belt conveyor in mining, port, metallurgy and other industries is crucial, and its noise affects the accuracy of the monitoring system. Fiber optic sensing technology is gradually applied to conveyor condition monitoring because of its high sensitivity and anti-interference. However, the signal collected by optical fiber often contains a large amount of noise, which requires an effective signal processing method. In this paper, we propose a fiber optic audio feature extraction method based on wavelet transform, which decomposes the signal at multiple scales by wavelet transform and extracts energy features to monitor the conveyor status. Experimental results show that the method can effectively extract key features, improve the accuracy of signal processing, and provide reliable support for fault detection and condition monitoring. This study introduces the principles of fiber optic sensing technology and wavelet transform, designs and implements a feature extraction algorithm based on wavelet transform, and verifies its effectiveness, hoping to provide new technical means and theoretical basis for intelligent monitoring and fault diagnosis of belt conveyor.
Comparative Analysis of Air Quality Index Using Large Language Models and Machine Learning
Authors: Sundaramurthy Shanmugam , Sai Harish G  , Reddy V Chandra Shekar
Published: November 2024

Accurate air quality prediction is crucial for environmental monitoring and public health. This study explores a novel approach using machine learning algorithms and large language models to predict the Air Quality Index (AQI). While traditional AQI prediction relies on complex models and extensive data on pollutants and meteorological factors, this research investigates the use of readily available fuel consumption data as an alternative predictor, given its close link to emissions. The study employs supervised machine learning algorithms, including Random Forest and Gradient Boosting, utilizing fuel consumption data as input features to build predictive models. Additionally, a state-of-the-art large language model, GPT-3.5-turbo-instruct, is fine-tuned on historical AQI data and evaluated for its predictive capabilities. The performance of both machine learning models and the language model is compared using various metrics, and the results demonstrate that both approaches achieve high AQI prediction accuracy, outperforming traditional methods based on pollutant concentration data. Notably, the fine-tuned language model exhibits superior performance, potentially due to its ability to capture complex dependencies and contextual information from the training data. This work highlights the potential of leveraging readily available fuel consumption data and advanced language models for accurate and cost-effective AQI prediction. The findings have significant implications for developing scalable air quality monitoring systems, enabling timely interventions and informed decision-making to mitigate the adverse effects of air pollution.
Investigation and Analysis of Mobile Learning Initiative of College Students in Internet Plus Environment—Based on a Survey of 1,035 College Students in Guangdong Universities as an Example
Authors: Wang Yanling , Lin Yaojia , Su Junyi
Published: November 2024

Mobile learning has become a new form of business in the era of digital education. In order to understand the current situation and needs of college students in mobile learning, this paper uses questionnaire survey and interview method to randomly select 1035 college students from universities in Guangdong as the research object to investigate the status and needs of using mobile devices (smart phones, Pads, e-readers, etc.). The survey found that college students have a large demand for mobile learning, and have the equipment conditions to carry out mobile learning. However, the autonomy of mobile learning is weak, the integration with teaching is less, college students accept a low degree of mobile learning, and the effect and evaluation feedback of mobile learning are not high. This study on the basis of the status quo investigation, in view of the current college students problems and challenges in mobile learning, put forward from the technical level, schools and teachers, family and individual level of multiple dimensions, build scientific ecological Internet + mobile learning mode, guide students to use mobile learning resources, enhance mobile learning will and behavior, effectively promote the college students’ personalized learning and independent growth.
A Phase-Space Approach to X-Ray Optics
Authors: Castano Victor M. , Gómez Alfredo
Published: November 2024

The basic concepts and properties of some phase-space mathematical functions, in particular of the Wigner distribution function, are reviewed. Then, the propagation and diffraction of x rays are considered from the point of view of the Wigner function, resulting in a simple method consisting in coordinate shifts in phase space, which can be easily implemented in a personal computer. The applications of this tool to x-ray technology are also discussed.
Multiresolution/multiorientation based nonlinear filters for image	enhancement and detection in digital mammography
Authors: Qian Wei , Sun Xuejun , Clark Robert
Published: November 2024

In this paper a novel hybrid filter architecture is presented that incorporates an adaptive multistage nonlinear filter (AMNF) and Multiresolution/Multiorientation Wavelet Transform (MMWT) specifically designed for image enhancement in medical imaging. The MMWT is used for multiresolution and/or multiorientation decomposition and reconstruction of the mammograms where selective reconstruction of subimages is used to perform further enhancement of the MCCs and masses. The specific clinical application is enhancement of microcalcification clusters (MCCs) and masses in digitized mammograms and the AMNF is used for noise suppression and image enhancement. This novel filter was evaluated using diagnostic images from two databases: (a) and (b). Database (a) has 100 single view mammograms at a resolution of 105 micron and 12 bits gray level. It contains 50 cases of normal mammograms and 50 cases of biopsy proven malignant MCCs. Database (b) has 100 single view mammograms at a resolution of 180 micron and 12 bits gray value. It contains 50 normal and 50 biopsy proven abnormal masses. Visual inspection of the enhanced images demonstrated improved visualization of MCCs/masses and the morphology of the individual subtle microcalcifications and masses compared with unprocessed images. The performance of the enhancement method was quantitatively evaluated using a Kalman Filtering Neural Network for MCCs and mass detection and applied to the digital mammograms of the database (a) and (b). The sensitivities (True Positive (TP) detection rate) of MCC cluster detection were 93% images respectively, and the average false positive (FP) detection rate was 1.35 FP and 1.47 MCCs/image respectively. The sensitivities of mass detection were 85% unprocessed images respectively and the average FP rates were 1.81 and 2.75 masses/image respectively. The Research results in this article demonstrate the importance of the hybrid filter architecture for enhancement in the computerized detection of MCCs and mass.
Fundamental study on non-invasive blood glucose sensing
Authors: Xu Kexin , Li Qingbo , Lu Zhang , Jiang Jingying
Published: November 2024

Diabetes is a disease which severely threatens the health of human beings. Unfortunately, current monitoring techniques with finger sticks discourage the regular use. Noninvasive spectroscopic measurement of blood glucose is a simple and painless technique, and reduces the long-term health care costs of diabetic patients due to no reagents. It is suitable for home use. Moreover, the establishment of the methodology not only applies to blood glucose noninvasive measurement, but also can be extended to noninvasive measurement of other analytes in body fluid, which will be of important significance for the development of the technique of clinical analysis.

In this paper, some fundamental researches, which have been achieved in our laboratory in the field of non-invasive blood glucose measurement, were introduced.

1. Fundamental research was done for the glucose concentrations from simple to complex samples with near and middle infrared spectroscopy:

(1) the relationship between the instrument precision and prediction accuracy of the glucose measurement;

(2) the change of the result of the quantitative measurement with the change of the complexity of samples;

(3) the attempt of increasing the prediction accuracy of the glucose measurement by improving the methods of modeling. The research results showed that it is feasible for non-invasive blood glucose measurement with near and middle infrared spectroscopy in theory, and the experimental results, from simple to complex samples, proved that it is effective for the methodology consisting of hardware and software.

2. According to the characteristics of human body measurement, the effects of measuring conditions on measurement results, such as: (1) the effect of measurement position; (2) the effect of measurement pressure; (3) the effect of measurement site; (4) the effect of measured individual, were investigated. With the fundamental researches, the special problems of human body measurement were solved. In addition, the practical and effective method of noninvasive human blood glucose measurement was proposed.
Approaching biomimetics in dental restorations via photonics
Authors: Kishen Anil , Asundi Anand
Published: November 2024

It is established that a natural system balances functional requirements with the anatomical optimizations it has achieved. Though such process of functional adaptation is recognized in bone tissue, any mode of functional adaptation in dental tissue is yet to be understood. In this study a three-dimensional digital photoelasticity is conducted to evaluate the nature of stress distribution in the sagittal aspect and the cross-sections of the dentine structure. Later, a fluoroscopic X-ray microscopic analysis and a microindentation experiments, are performed on different sections obtained from the sagittal and cross-sections of the dentine. These experiments aided in correlating the multi-plane pattern of mineralization and the spatial gradients in elastic modulus in the original dentine structure with the three-dimensional stress distribution in photoelastic models. This study highlights dentine structure as a biologically graded structure to functional loads.
An improved real-time navigator gating algorithm for reducing	motion effects in coronary magnetic resonance angiography
Authors: Nuval Anthony , Nguyen Thanh D. , Watts Richard , Wang Yi
Published: November 2024

The phase ordering with automatic window selection (PAWS) algorithm for respiratory gating in magnetic resonance imaging is improved by further smoothing motion distribution in k-space. This is achieved by requiring that the displacement discontinuities in k-space and the range of displacement during the acquisition of the center 30% region of k-space are limited to a fraction (1/3 in this study) of the gating window. Simulation results and in vivo imaging experiments suggest that these modifications reduce the amount of artifacts at a reasonable cost of additional scan time as compared to the original PAWS algorithm.
A pilot investigation of new superparamagnetic iron oxide	(ferumoxytol) as a contrast agent for cardiovascular MRI
Authors: Prince Martin R. , Zhang Hong Lei , Chabra Shalini G. , Jacobs Paula , Wang Yi
Published: November 2024

Purpose: To evaluate the imaging potential of ferumoxytol, a new superparamagnetic iron oxide colloidal blood pool contrast agent.

Materials and Methods: Magnetic resonance (MR) imaging at 1.5 Tesla was performed before and after intravenous injection of ferumoxytol using escalating doses of 0.4, 0.8, 1.2 and 1.6 mg Fe/kg for a total of 4 mg Fe/kg in five subjects imaged with 3D MR Angiography (MRA) of the trifurcation after each dose. In five subjects cardiac cine MRI was performed pre and post 4.0 mg Fe/kg. Image quality was assessed by measuring signal to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in the vascular structures. Pre- and post-dose urine and blood tests as well as EKG/vital sign monitoring were performed to evaluate safety and blood samples were collected for T1 relaxivity measurements.

Results: Cumulative doses of 0, 0.4, 1.2, 2.4 and 4 mg Fe/kg yielded mean SNR in the arteries of 10, 16, 39, 57 and 69 respectively indicating that the higher doses produced higher SNR on 3D vascular images. Similarly aorta SNR on 2D time-of-flight increased from 11.8 without Fe to 15.4 post Fe (p = 0.004) indicating improved image quality on MRA sequences optimized for use without contrast. At 4 mg Fe/kg there was a substantial T1 shortening measured in the blood from 1990 ± 573 ms to 80 ± 42 ms (p < 0.0001), corresponding to the increased SNR. Images of large vascular structures including cardiac chambers, aorta, and pulmonary arteries were excellent post ferumoxytol but images of smaller arteries of the trifurcation were difficult to evaluate due to enhancement of the overlapping veins. No serious adverse events occurred.

Conclusion: The new superparamagnetic iron oxide colloid ferumoxytol is a promising blood pool agent especially for cardiac, aorta and pulmonary imaging.
Feasibility of using a kinestatic charge detector for dual-energy	chest radiography
Authors: Schmithorst Vincent J. , Endorf Robert J. , Kulatunga Sunil , Spelic David C. , DiBianca Frank A. , Rodriguez Carlos , Zeman Herbert D. , Zhu Zeping , Giakos George C.
Published: November 2024

The feasibility of using a Kinestatic Charge Detector (KCD) for dual-energy chest radiography is investigated. A KCD is a gas ionization chamber used with a scanning slot-beam geometry. Dual-energy imaging involves acquisition of two images with different mean photon energies which can then be reconstructed using a suitable algorithm to form images of two basis materials, such as bone and soft-tissue. With a KCD, dual-energy imaging may be performed either by taking two separate exposures at different kVp settings (the dual-kVp method) or by taking a single exposure with the KCD segmented into a front and back region (the split-detector method), as the higher energy photons will be preferentially absorbed in the back region. We have investigated the feasibility of a dual-energy KCD using computer simulations for both dual-kVp and split-detector systems. The theoretically determined contrast resolutions for aluminum and plexiglas were found to be sufficient for clinical diagnosis; however, electronic noise was found to be a major limiting factor. The dual-kVp method was found to yield significant improvements over the split-detector method at high material thicknesses.
Studies on implementation of the Katsevich algorithm for spiral	cone-beam CT
Authors: Yu Hengyong , Wang Ge
Published: November 2024

Recently, Katsevich proposed the first exact helical cone-beam reconstruction algorithm that takes longitudinally truncated data collected from part of a scanning turn. A key theoretical basis is that any point inside the scanning helix belongs to one and only one PI-line. Unfortunately, he only provided a general formulation and did not describe the implementation details. To make this complicated algorithm more transparent, we report here specifically how to program the Katsevich algorithm in the planar detector geometry. As an important component, we also analyze the effects of various implementation parameters on the image quality. Our results are intended to be valuable for those who are interested in evaluating, improving and extending the Katsevich approach.
Optimization of x-ray conversion efficiency of laser-preformed	metallic plasma
Authors: Primout M.
Published: November 2024

In the context of target optimization for multi-keV x-ray production in laser experiment, we have adapted a method for visual observation of the conversion efficiency calculated from a large number of 1-D hydro-radiative simulations. A Monte Carlo method based on uniformly distributed random values for parameters in predefinite ranges has been used. The conversion efficiency can be considered as one constraint which leads to correlations between parameters. In addition, the sensitivity of the conversion efficiency to the various target and laser parameters appears visually.
Blind deblurring of spiral CT images Based on ENR and Wiener	filter
Authors: Wang Jing , Wang Ge , Jiang Ming
Published: November 2024

In previous studies, we developed a blind deblurring algorithm based on the edge-to-noise ratio (ENR) and EM algorithm to improve the quality of spiral CT images. In this work, we apply the Wiener filter in place of the EM algorithm to improve the timing performance. The algorithm works well in patient studies. After fully automatic blind deblurring, the conspicuity of the submillimeter features of the cochlea image is substantially improved. The new ENR-Wiener blind deblurring approach significantly improves the computation speed with comparable image quality in previous studies.
A novel $^{99m}$Tc hyaluronate probe for SPECT	imaging of lung cancer - feasibility study in an animal model
Authors: Qiang Yong Gang , Liao Yong Hua , Li Jian , Zhang Xiu Ping , Huang Zheng
Published: November 2024

This study described a novel radioactive probe for SPECT imaging of lung cancer. The probe was consisted of $^{99m}$ Tc labeled cartilage link protein (CLP). The CLP, a hyaluronate binding protein, was isolated from bovine nose cartilage and purified on a chromatography column. $^{99m}$ Tc labeling was carried out by pre-treating CLP with SnCl $_2$ . The feasibility of this probe for lung cancer imaging was tested in vivo in an animal model. The hyaluronate probe showed a fairly good binding activity towards both natural and tumor hyaluronic acid in in vitro and in vivo assays. The preliminary feasibility study in a human lung cancer bearing mouse model showed that the probe might be useful for tumor imaging.
Spectral properties of a soft glass photonic crystal fiber
Authors: Beloglazov V.I. , Chainikov M.V. , Skibina Yu. S. , Tuchin V.V.
Published: November 2024

We have created for the first time the photonic crystal optical fiber having the photonic band gap in the visible and NIR range of spectrum. This fiber consists of concentric layers of air holes of variable diameter with hollow cores. We have carried out studies on their transmission spectra formation. We have displayed the influence of geometry and arrangement of a fiber on its photonic band gap width and structure. It was established that changes of geometrical structure of a fiber allows one to control effectively the width of the photonic band gap that gives new opportunities to guide visible and NIR light.
Technologies of manufacturing polycapillary optics for x-ray	engineering
Authors: Beloglazov V.I. , Langhoff N. , Tuchin V.V. , Bjeoumikhov A. , Bjeoumikhova Z. , Wedel R. , Skibina N.B. , Skibina Yu. S. , Chainikov M.V.
Published: November 2024

The polycapillary lenses allow realizing compact x-ray analytical devices. X-ray capillary optics is based on the principle of transportation of radiation by means of repeatable reflection of radiation from a smooth surface of internal walls of glass capillary layers. The developed policapillary structures are used for formation of converging, diverging, and parallel beams in a wide spectral range. The mono- and polycapillary structures are produced using fiber glass technology, which consists of the repeatable pulling flown down of packages in similarity, sintering of preparations and formation form of capillary lenses. The analysis of technology of manufacturing of polycapillary compact x-ray systems is offered.
Semi-quantification of cementing products using X-ray diffraction	technique in stabilized aggregate
Authors: Khoury Naji , Zaman Musharraf , Laguros Joakim
Published: November 2024

A laboratory study was undertaken to investigate the performance of limestone aggregate base stabilized with different stabilizing agents, namely, class C fly ash, cement kiln dust and fluidized bed ash. Cylindrical specimens were compacted and cured for 1 hour, 3 days and 28 days prior to tests of unconfined compressive strength (UCS), scanning electron microscopy, energy-dispersive spectrometry and X-ray diffraction. Results showed that the UCS values increased with curing time. It was also found that the different stabilizing agents produced different UCS values. The reference intensity ratio (RIR) method was employed to identify and quantify the mass percent of minerals and cementing compounds in the mixtures. Results revealed the formation of cementing compounds such as ettringite, C-S-H, C-A-H and C-A-S-H, which were responsible for an increase in the UCS values. In this study, the sum of all the cementing compounds (SCC) showed the same beneficiation trend as the UCS trend with curing time. Finally, the UCS values correlated fairly well with SCC. The SEM micrographs showed the intensity of crystal formation and hydration coating, which increased with curing time and percentage of additive.
Source intensity optimization in quantitative three-dimensional	diffuse optical tomography
Authors: Li Changqing , Jiang Huabei
Published: November 2024

We present a method that optimizes the source intensity distribution in three-dimensional (3D) diffuse optical tomography (DOT). We evaluate this method using a series of phantom experiments where different contrast levels between the target and background are considered. With the new method, while the quality of both absorption and scattering images is quantitatively improved, the improvement in absorption image reconstruction is especially substantial: a relative error of less than 0.95% for recovered peak value in the target region is achieved for high contrast case and of less than 18.0% for low contrast case.
Diffraction-enhanced imaging with synchrotron radiation X-ray for	liver
Authors: Peng Yi-Feng , Chen Shaoliang , Tang Guangyu , Chen Yuesheng , Shen Renjie , Chen Aiping , Zhu Pei-Ping , Huang Wan-Xia , Yuan Qing-Xi
Published: November 2024

To evaluate the value of phase contrast x-ray imaging (PCI) with a synchrotron radiation (SR) source in which we performed hepatic imaging in the 4W1A beamline of Beijing Synchrotron Radiation Facility (BSRF). The hepatic specimens from a SD mouse, a normal adult and a biliary cirrhosis patient were imaged with the diffraction enhanced imaging (DEI) technique. We showed that the three grade vessel branches in the mouse, the hepatic lobule of the normal adult and the enlarged bile ducts of the biliary cirrhosis patient could all be clearly revealed with the DEI technique. Our results indicated that the PCI techniques including DEI might improve hepatic imaging performance in spatial resolution and tissue contrast.
A free-geometry cone beam CT and its FDK-type reconstruction
Authors: Xing Yuxiang , Zhang Li
Published: November 2024

In recent years, image reconstruction methods for cone-beam computed tomography (CT) have been widely discussed with default setting of geometry that the normal vector of the detector plane passing the X ray source crosses the rotation axis. However, this may not be true in reality. In this paper, we defined a cone beam CT with freedom in the arrangement of an X ray source and detector. A circular trajectory scan is studied. An FDK-type reconstruction is derived for this kind of CT geometry. The reconstruction formulae are similar to the well-known FDK. The implementation is simple and straightforward. It reduces to the original FDK if the default setting of geometry for traditional circular CT is applied. Hence, one can adapt our method directly to current applications and allow more flexibility in system arrangement. A computer-simulation study is performed to validate the reconstruction algorithm and demonstrate its performance. The proposed algorithm for a free-geometry cone beam CT can reconstruct the exact mid-plane image of the object and a volume within a reasonable cone angle with very small error like FDK for traditional CT.
Intuitive dimensional analyses of the energy and atomic number	dependences of the cross sections for radiation interaction with matter
Authors: Wang Yi
Published: November 2024

Scattering cross sections of radiation interactions with matter form the foundation for diagnostic x-ray imaging, nuclear medicine, and radiotherapy. These cross sections are typically presented as numerical charts in medical physics literature or complicated formulas in quantum electrodynamics literature. There seems to be a lack of comprehensible explanations for these cross section coefficients. Intuitive dimensional estimations of the dependences on photon energy and atomic number for radiation matter interaction cross sections are provided using elementary concepts of classical and quantum physics for Compton scattering, Rayleigh scattering, photoelectric effects, and pair production. This easy-to-understand approach is found to yield dimensional relations similar to that derived from quantum electrodynamics.
Application of frequency domain processing to X-ray radiographic	images of welding defects
Authors: Rajab Maher I. , El-Benawy Talaat A. , Al-Hazmi Mohammed W.
Published: November 2024

X-ray radiographic technique is widely used as Nondestructive Testing (NDT) for inspection of welding joints. The quality of X-ray images is frequently sensitive for noise, lighting and working place surroundings. Therefore, such images need to be carefully examined to identify welding discontinuities. However, the human interpretative are usually contradictory and may cause confusion. Present work has proposed an image processing technique based on frequency domain processing to clarify the X-ray radiographic images taken for different welding discontinuities. The images are captured using low-resolution video camera and high-resolution digital camera. Preprocessing imaging tasks are performed to reduce the noise in the low-resolution video sequence images. Subsequently, low-pass followed by emphasis high-pass frequency filters are applied to enhance the images with appropriate cut-off frequencies. It is found that high-frequency domain image filtering is enhancing the morphological features of the X-ray images. The enhanced images become visually cleared and the welding discontinuities are possibility accessible.
Detection of brain tumor contours by using edge detection method	over intensity versus perceived brightness gradients
Authors: Dirican Bahar , Oysul Kaan , Pahsa Alper , Beyzadeoǧu Murat
Published: November 2024

In this work, a new contour detection method is studied for detecting brain tumor regions based on their gradient magnitude information. Gradient magnitude data, an edge detection method, is generated from the brain slice image intensity or perceived brightness information. Contour map of the brain tumor is generated by using the gradient magnitude differences of the template masks (cropped from brain slice tumor image) and the sample masks (traverses the image) raw pixel and perceived brightness (luminance) date. Then these differences are averaged and normalized to produce edge profiles of the brain tumor region contours. This data is used by the remote surgical devices for removing the tumor area.
Manual control of patient table for bolus-chasing CT	angiography
Authors: Bai Henri , Zeng Kai , Bai Erwei , Wang Ge
Published: November 2024

In order to reduce contrast dose and radiation exposure involved in CT angiography, an automatic adaptive control scheme was proposed for bolus chasing, which offers substantial improvements over the conventional constant speed control scheme. In this paper, a manual control scheme is proposed to utilize the expert's knowledge optimally based on real-time imaging feedback. The technical objective is to synchronize the bolus dynamics and the imaging aperture. To test the proposed technique, a realistic simulator is designed, developed and evaluated. It is shown statistically that the manual control outperforms the traditional constant speed control.
An alternative derivation and description of Smith's data	sufficiency condition for exact cone-beam reconstruction
Authors: Li Liang , Kang Kejun , Chen Zhiqiang , Zhang Li , Xing Yuxiang , Yu Hengyong , Wang Ge
Published: November 2024

In this paper, we present an alternative derivation and description of Smith's data sufficiency condition for exact cone-beam reconstruction. Different from Smith's condition, our condition with new description can be considered as a bridge between the approximate and exact cone-beam reconstruction. When the data sufficiency condition is satisfied, a set of parallel-beam projections can be obtained for exact 3-D reconstruction. When it is not satisfied, some directional parallel-beam projections will be missed, and only approximate reconstruction is achieved. Although our data sufficiency condition is theoretically proved to be equivalent to Smith's condition, its derivation is totally different.
Application of projection simulation based on physical imaging	model to the evaluation of beam hardening corrections in X-ray transmission	tomography
Authors: Tang Shaojie , Mou Xuanqin , Yang Ying , Xu Qiong , Yu Hengyong
Published: November 2024

The polychromatic spectrum of photons emitted by an X-ray tube in medical diagnostic CT system brings beam hardening artifact. Although many correction methods have been developed, it is still the major artifact in clinical CT imaging. Motivated by CT reconstruction researches benefiting from mathematical phantoms, one so-called physical mathematical phantom and its projection simulation are presented in this paper, which are used in comprehensive evaluation of beam hardening corrections. Due to the inherent merits as compared to discrete and stochastic simulations, an analytic method is proposed to simulate the polychromatic projections of FORBILD head phantom. Firstly, CT-numbers are mapped to material compositions under the precondition sub-regions represent different human tissues. Second, boundary parameters of sub-regions are determined by the presented algorithms. Finally, projections are calculated according to X-ray energy spectrum. For validating the usefulness of our simulation, several typical correction methods are analyzed using simulated projections. The performance of every correction is exhibited distinctly. The analysis results show that there are still the spaces to improve those correction methods.
Involvement of Bax and caspase-3 activation in Chan-Su-induced	ASTC-a-1 cell apoptosis
Authors: Sun Lei , Wang Xiao-Ping , Chen Tong-Sheng , Wang Long-Xiang
Published: November 2024

Chan-Su (CS), a traditional Chinese medicine, is one of the most potent Chinese medicines currently used in cancer chemoprevention and treatment. However, the molecular mechanism of CS-induced-apoptosis is still unclear. This study investigated the molecular mechanism of CS-induced apoptosis using fluorescence resonance energy transfer (FRET) and confocal fluorescence microscope techniques. CS dose-dependently inhibited cell viability cytotoxicity, which was assayed by Cell Counting Kit (CCK-8) and Hoechst33258 staining. Bax translocation to mitochondria was observed in single living cell transfected with GFP-Bax plasmid. The mitochondrial membrane potential (ΔΨ $_{m}$ ) loss was also measured in CS-treated cells. And ASTC-a-1 cell expressed stably with SCAT3 plasmid was used to examine if caspase-3 was activated by CS. z-VAD-fmk, a broad-caspase spectrum inhibitor, was found to significantly reduce the inhibition of CS on the cell viability. Overall, our data demonstrated that CS induced ASTC-a-1cells apoptosis in a dose-dependent manner, and Bax, caspase-3 and mitochondrial stress were involved in CS-induced apoptosis. Our findings extend the knowledge about the cellular signaling mechanisms mediating CS-induced apoptosis.
A LabVIEW driver for X-ray flat-panel detector
Authors: Bi Kun , Liu Qian , Lv Xiaohua , Luo Qingming , Zeng Shaoqun
Published: November 2024

This article introduces a driver design of the X-ray flat panel detector which is based on the LabVIEW. The functions in the flat panel detector c code software development kit are classified firstly. And then these classifications are encapsulated into VI modules with some intelligent processing, which described detailedly in this article. Exemplified by the digital ray imaging system, the installation of the system, the implementation of the various functional modules, the procedures to develop the framework of entire application software and the improvement of the error messages are described in this article. The high performance demonstrated by the imaging results indicates that the controlling and collecting system based on virtual instrument is able to satisfy the requirements of scientific research and the development of prototype machine and software.
Radiography simulation based on point-kernel model and dose	buildup factors
Authors: Marinković Predrag , Ilić Radovan
Published: November 2024

Three-dimensional point-kernel multiple scatter model for radiography simulation, based on dose X-ray buildup factors, is proposed and validated to Monte Carlo simulation. This model embraces nonuniform attenuation in object of imaging (patient body tissue). Photon multiple scattering is treated as in the point-kernel integration gamma ray shielding problems via scatter voxels. First order Compton scattering is described by means of Klein-Nishina formula. Photon multiple scattering is accounted by using dose buildup factors. The proposed model is convenient in those situations where more exact techniques, like Monte Carlo, are not time consuming acceptable.
A general region-of-interest image reconstruction approach with	truncated Hilbert transform
Authors: Li Liang , Kang Kejun , Chen Zhiqiang , Zhang Li , Xing Yuxiang
Published: November 2024

This paper presents a novel data sufficiency condition that unique and stable ROI reconstruction can be achieved from a more flexible family of data sets. To the interior problem, it allows the ROI (Region-of-interest) can be reconstructed from the line integrals passing through this ROI and a small region B located anywhere as long as the image is known on B. Especially, ROI reconstruction can be achieved without any other a priori knowledge when region B is placed outside the object support. We also develop a general reconstruction algorithm with the DBP-POCS (Differentiated backprojection-projection onto convex sets) method. Finally, both numerical and real experiments were done to illustrate the new data sufficiency condition and the good stability of the ROI reconstruction algorithm.
A post-scan method for correcting artefacts of slow geometry	changes during micro-tomographic scans
Authors: Salmon P.L. , Liu X. , Sasov A.
Published: November 2024

Micro-CT imaging of objects at very high magnification runs into the problem of small geometric movements of the x-ray emission spot relative to the object, thermally induced or otherwise, causing magnified shifts in the projection images during scanning. This produces movement artefacts in the reconstructed images. Here a technique is described to correct such movements by adding a short reference scan at the end of a high magnification scan, with a very large rotation step. Where geometry changes during a scan are slow, such movements can be considered minimal during this very short "post-scan". Registration of the post-scan images with corresponding images in the main scan allow X/Y pixel shifts in the projection images associated with the geometry movement to be calculated, and corrected during reconstruction. This post-scan correction method was applied here to scans of three small objects, all with a voxel size less than one micron, in a desktop micro-CT and a nano-CT scanner. The method substantially reduced movement artefacts from the reconstructed images, improving image quality and resolution. Where the geometry movement results largely from thermal movement of the x-ray micro-focus emission spot, the post-scan method allows the reconstruction of the spatio-temporal trajectory of this spot movement.
Image reconstruction in reduced circular sinusoidal cone-beam CT
Authors: Xia Dan , Cho Seungryong , Pan Xiaochuan
Published: November 2024

Non-circular scanning geometries such as helix or circular sinusoid have been used or proposed for cone-beam computed tomography (CBCT), because they provide sufficient data for numerically stable and exact image reconstruction within the scanned volume. Analytic algorithms have been developed for image reconstruction from cone-beam data acquired with a full-scan circular sinusoidal trajectory. In this work, we propose an innovative imaging approach in which a reduced-scan circular sinusoidal trajectory is used for acquiring data sufficient for exact 3D image reconstruction. A filtered backprojection (FBP) algorithm based on Pack-Noo's reconstruction formula is applied for image reconstruction in reduced-scan circular sinusoidal scans. We have conducted numerical studies to demonstrate the reduced-scan approach and to validate the FBP reconstruction algorithm in the proposed approach. The proposed scanning method can contribute to increasing the throughput of a scanner, while improving the image quality compared to a conventional circular scan.
Efficient x-ray image enhancement algorithm using image	fusion
Authors: Shen Kuan , Wen Yumei , Cai Yufang
Published: November 2024

Multiresolution Analysis (MRA) plays an important role in image and signal processing fields, and it can extract information at different scales. Image fusion is a process of combining two or more images into an image, which extracts features from source images and provides more information than one image. The research presented in this article is aimed at the development of an automated imaging enhancement system in digital radiography (DR) images, which can clearly display all the defects in one image and don't bring blocking effect. In terms of characteristic of the collected radiographic signals, in the proposed scheme the subsection of signals is mapped to 0–255 gray scale to form several gray images and then these images are fused to form a new enhanced image. This article focuses on comparing the discriminating power of several multiresolution images decomposing methods using contrast pyramid, wavelet, and ridgelet respectively. The algorithms are extensively tested and the results are compared with standard image enhancement algorithms. Tests indicate that the fused images present a more detailed representation of the x-ray image. Detection, recognition, and search tasks may therefore benefit from this.
Measurements of the Modulation Transfer Function, Normalized Noise	Power Spectrum and Detective Quantum Efficiency for two flat panel detectors: A	Fluoroscopic and a Cone Beam Computer Tomography Flat Panel Detectors
Authors: Benítez Ricardo Betancourt , Ning Ruola , Conover David , Liu Shaohua
Published: November 2024

The physical performance of two Flat Panel Detectors has been evaluated. The first Flat Panel Detector is for Fluoroscopic applications, Varian PaxScan 2520, and the second is for Cone Beam Computer Tomography applications, Varian PaxScan 4030CB. First, the spectrum of the X-ray source was measured. Second, the linearity of the detectors was investigated by using an ionization chamber and the average ADU values of the detectors. Third, the temporal resolution was characterized by evaluating their image lag. Fourth, their spatial resolution was characterized by the pre-sampling Modulation Transfer Function. Fifth, the Normalized Noise Power Spectrum was calculated for various exposures levels. Finally, the Detective Quantum Efficiency was obtained as a function of spatial frequency and entrance exposure. The results illustrate that the physical performance in Detective Quantum Efficiency and Normalized Noise Power Spectrum of the Cone Beam Computer Tomography detector is superior to that of the fluoroscopic detector whereas the latter detector has a higher spatial resolution as demonstrated by larger values of its Modulation Transfer Function at large spatial frequencies.
Dose reduction with adaptive bolus chasing computed tomography	angiography
Authors: Cai Zhijun , Bai Er-Wei , Wang Ge , Sharafuddin Melhem J. , Abada Hicham T.
Published: November 2024

Computed Tomography (CT) has become an effective diagnosis and evaluating tool in clinical; however, its radiation exposure has drawn great attention as more and more CT scans are performed every year. How to reduce the radiation dose and meanwhile keep the resultant CT images diagnosable becomes an important research topic. In this paper, we propose a dose reduction approach along with the adaptive bolus chasing CT Angiography (CTA) techniques, which are capable of tracking the contrast bolus peak over all the blood vessel segments during the CTA scan. By modulating the tube current (and collimator width) online, we can reduce the total radiation dose and maintain the contrast to noise ratio (CNR) of the blood vessel. Numerical experiments on reference DSA data sets show that by using the proposed dose reduction method, the effective radiation dose can be saved about 39%.
Simulation of induced electric field distribution based on	five-sphere model used in rTMS
Authors: Pu Lina , Liu Zhipeng , Yin Tao , An Hao , Li Song
Published: November 2024

Repetitive Transcranial magnetic stimulation (TMS) is a relatively new technique, which is non-invasive and painless used to stimulate the central and peripheral neural tissues. The principle is generating time-varying magnetic fields to stimulate the cerebral cortex neuron and inducing eddy current inside the tissues. Many researches study on the distributing of magnetic field and electric field induced inside the human brain, whereas the static electric field was neglected roughly in many studies. In this paper, a five-sphere model is established to simulate the human head used in rTMS. According to the different dielectric properties of the head tissues, the Laplace equation of static electric field is deduced by both of Gauss theorem and current's continuity principle. Boundary conditions used in different interface between two adjacent layers in the five-sphere model is proposed in this paper. Simulating study is conducted to calculate the distribution of the electric field in the model. Simulating results suggest that the model is useful to get the parameters of the most focus coil. Therefore this study could be potential to promote the development of rTMS stimulator.
Fusion of CT and MR images using an improved wavelet based	method
Authors: Yang Yong , Park Dong Sun , Huang Shuying , Yang Jucheng
Published: November 2024

The fusion of multimodal medical images plays an important role in many clinical applications as it can support more accurate information than any individual source image. This paper presents a novel approach for fusion of computed tomography (CT) and magnetic resonance (MR) images based on wavelet transform. The medical images to be fused are firstly decomposed into multiscale representations by the wavelet transform. Then, by considering the physical meaning of wavelet coefficients and the characteristics of the CT and MR images, the coefficients of the low frequency band and high frequency bands are treated with different schemes: the former is performed with a maximum-selection (MS) rule, and the latter is convolved with a Laplacian operator followed by a MS rule. Finally, the fused image is reconstructed by using the inverse wavelet transform with the combined wavelet coefficients. The performance of our method is qualitatively and quantitatively compared with some existing fusion approaches. The experimental results can demonstrate that the proposed method is a promising and effective technique for fusion of CT and MR images.
Patient exposure dose for chest and skull radiographies in	Mazandaran hospitals
Authors: Etemadinezhad Siavash , Rahimi Seyed Ali
Published: November 2024

Background and purpose: Radiographic techniques are essential methods of diagnosis, and their use has been increased, especially with the development of the new technologies. Inappropriate administration of these techniques may put both the patients and personnel at unnecessary risks. The objective of this research was to measure the skin dose of chest and skull radiographies used in Mazandaran hospitals and to compare these doses with national and international standards.

Materials and methods: In this cross-sectional study, six X-ray generators at six hospitals affiliated to Mazandaran University of Medical Sciences were included. One hundred and twenty patients referred to the radiology wards for radiographic examinations of chest and skull with normal body mass index (BMI) were selected (20 patients for each radiography unit). The generators were matched for mAs, kvp, type of amplifier sheets, and technical conditions as much as possible. Calibrated thermo luminescence dosimeters (TLD-USA, Lif-100) were used to measure the skin dose by placing them on the patients' back and the absorbed doses by TLDs were read by a TLD reader (model: Harshuu, TLD3500, Japan).

Results: The mean values of the skin dose were 0.51 mGray for posteroanterior (PA), chest X-ray (CXR), 3.36 mGray for lateral CXR, 7.25 mGray for anterroposterior (AP) or PA skull X-rays, and 7.59 mGray for lateral skull X-rays. The measured values were higher than the national and international standards.

Conclusion: The results of this research revealed that the conditions of the X-ray generators should be monitored and modified periodically. Modifying the X-ray generators plus improving technicians' skills would, to some extent, reduce the radiation exposure of the patients.
X-ray and optical crystallographic parameters investigations of	high frequency induction melted Al-(α-Al$_{2}$O$_{3}$)	alloys
Authors: Bourbia A. , Draissia M. , Bedboudi H. , Boulkhessaim S. , Debili M.Y.
Published: November 2024

This article deals with the microstructural strengthening mechanisms of aluminium by means of hard α-Al $_{2}$ O $_{3}$ alumina fine particles. A broad of understanding views covering materials preparations, elaboration process, characterization techniques and associated microstructural characteristic parameters measurements is given.

In order to investigate the microstructural characteristic parameters and the mechanical strengthening mechanisms of pure aluminium by hard fine particles, a set of Al-(α-Al $_{2}$ O $_{3}$ ) alloys samples were made under vacuum by high fusion temperature melting, the high frequency (HF) process, and rapidly solidified under ambient temperature from a mixture of cold-compacted high-pure fine Al and α-Al $_{2}$ O $_{3}$ powders. The as-solidified Al-(α-Al $__{2}$ O $_{3}$ ) alloys were characterized by means of X-ray diffraction (XRD) analyses, optical microscopy observations and Vickers microhardness tests in both brut and heat-treated states. It was found that the as-solidified HF Al-(α-Al $_{2}$ O $_{3}$ ) alloys with compositions below 4 wt.% (α-Al $_{2}_O_{3}$ ) are single-phase microstructures of the solid solution FCC Al phase and over two-phase microstructures of the solid solution FCC Al and the Rhombohedral α-Al $_{2}$ O $_{3}$ phases. The optical micrographs reveal the presence of a grain size refinement in these alloys. Vickers microhardness of the as-solidified Al-(α-Al $_{2}$ O $_{3}$ ) is increased by means of pure fine α-Al $_{2}$ O $_{3}$ alumina particles. These combined effects of strengthening and grain size refinement observed in the as-solidified Al-(α-Al $_{2}$ O $_{3}$ ) alloys are essentially due to a strengthening of Al by the α-Al $_{2}$ O $_{3}$ alumina particles insertion in the (HF) melted and rapidly solidified alloys.