Journal of X-Ray Science and Technology - Volume 25, issue 4

Authors: Yu, Yi | Li, Jianlong | Guo, Lian | Gu, Taifu | Xiao, Ruihai | Ye, Ye | Pan, Qiufeng | Zhang, Yuanyuan | Huang, Hongwei

Article Type: Research Article

Abstract: Horseshoe kidney deformity with duplex urinary collecting systems is a rare congenital urinary tract defect. Clinically, it is very difficult to visually observe and examine the whole anatomic structure and information with the regular 2D diagnostic imaging tools. Here, we report a case in which a middle age patient has bilateral duplex urinary collecting systems and horseshoe kidney deformity accompanied with right renal ureteral calculi and hydronephrosis. It was diagnosed by magnetic resonance urography with urinary system 3D reconstruction. The imaging and display method provides valuable information about abnormal anatomic structures of the kidneys and the related stone diseases for …preoperative planning. Show more

Keywords: Duplex urinary collecting system, horseshoe kidney, calculi, MRU

DOI: 10.3233/XST-17250

Citation: Journal of X-Ray Science and Technology, vol. 25, no. 4, pp. 667-672, 2017

Authors: Niu, Shanzhou | Huang, Jing | Bian, Zhaoying | Zeng, Dong | Chen, Wufan | Yu, Gaohang | Liang, Zhengrong | Ma, Jianhua

Article Type: Research Article

Abstract: BCKGROUND: Accurate statistical model of the measured projection data is essential for computed tomography (CT) image reconstruction. The transmission data can be described by a compound Poisson distribution upon an electronic noise background. However, such a statistical distribution is numerically intractable for image reconstruction. OBJECTIVE: Although the sinogram data is easily manipulated, it lacks a statistical description for image reconstruction. To address this problem, we present an alpha-divergence constrained total generalized variation (AD-TGV) method for sparse-view x-ray CT image reconstruction. METHODS: The AD-TGV method is formulated as an optimization problem, which balances the alpha-divergence (AD) fidelity …and total generalized variation (TGV) regularization in one framework. The alpha-divergence is used to measure the discrepancy between the measured and estimated projection data. The TGV regularization can effectively eliminate the staircase and patchy artifacts which is often observed in total variation (TV) regularization. A modified proximal forward-backward splitting algorithm was proposed to minimize the associated objective function. RESULTS: Qualitative and quantitative evaluations were carried out on both phantom and patient data. Compared with the original TV-based method, the evaluations clearly demonstrate that the AD-TGV method achieves higher accuracy and lower noise, while preserving structural details. CONCLUSIONS: The experimental results show that the presented AD-TGV method can achieve more gains over the AD-TV method in preserving structural details and suppressing image noise and undesired patchy artifacts. The authors can draw the conclusion that the presented AD-TGV method is potential for radiation dose reduction by lowering the milliampere-seconds (mAs) and/or reducing the number of projection views. Show more

Keywords: Sparse-view X-ray CT, iterative reconstruction, alpha-divergence, total generalized variation

DOI: 10.3233/XST-16239

Citation: Journal of X-Ray Science and Technology, vol. 25, no. 4, pp. 673-688, 2017

Authors: Han, Shurong | Huang, Yeqing

Article Type: Research Article

Abstract: 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. Contrary to the other domestic studies, this study considers a …three-sector dynamical stochastic general equilibrium REC model. In this model there are two consumption sectors, whereby one is labour intensive and another is capital intensive. The more capital intensive investment sector only introduces technology shocks in the medical imaging market. Our response functions and Monte-Carlo simulation results show that the model can explain 90% of the volatility of consummation relative to GDP, and explain the correlation between consumption and GDP. The results demonstrated the significant correlation between the technological reform in medical imaging and volatility in the labour market on Chinese macro economy development. Show more

Keywords: Medical imaging, technology shock, economic volatility, real economic cycle, computational market analysis, technological reform

DOI: 10.3233/XST-17300

Citation: Journal of X-Ray Science and Technology, vol. 25, no. 4, pp. 689-700, 2017

Authors: Liu, Xia | Liu, Liansheng | Hou, Fen | Zhou, Zhifeng | Wu, Qingying | Li, Hengguo

Article Type: Research Article

Abstract: 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. RESULTS: Gray matter volume was lower in some regions in Das. By selecting the five most reduced regions, i.e. superior frontal gyrus, orbitofrontal cortex (OFC), …insula, hippocampus, and cerebellum posterior lobe, as regions of interest (ROIs) for FC analysis, results showed that DAs had greater FC between the inferior temporal gyrus and superior frontal gyrus, OFC and cerebellum posterior lobe. Conversely, the divers had lesser FC between OFC and putamen, superior frontal gyrus and caudate. CONCLUSIONS: VBM differences suggest that diving training entails more effective synaptic and/or neuronal pruning processes in motor structures. Indeed, cortical volumetric decreases in the DAs group are associated with increased FC among certain motor-related regions. We conclude that motor learning in adolescence alters brain structure in association with changes in FC between the relevant cortical and subcortical regions. Show more

Keywords: Diving athletes, VBM, gray matter volume, functional connectivity, resting-state motor network

DOI: 10.3233/XST-17305

Citation: Journal of X-Ray Science and Technology, vol. 25, no. 4, pp. 701-710, 2017

Authors: Wei, Wei | Hong, Jie | Wang, Chao | Wang, Lu

Article Type: Research Article

Abstract: The recorded surface Electromyogram (sEMG) signals is inevitably influenced by noise during the signal acquisition process. Because of the constant deviation that is known as the Pseudo-Gibbs phenomenon, which exists in conventional wavelet threshold de-noising, noise pertaining to sEMG is inevitable. In order to avoid or minimize noise in the recorded sEMG signals, the objective of this study is to investigate the feasibility of developing a new de-nosing function that uses the advantage of the adaptive threshold adopted in the Brige-Massart algorithm and test the performance of the new function. The simulation results show that applying this new de-noising function …could effectively remove noise in the recorded sEMG signals. Furthermore, when compared with conventional threshold de-noising function, the new function achieved higher performed de-noising effect, and thereby enabling better signal analysis subsequently. Show more

Keywords: Surface electromyogram signal, de-noising, threshold function, signal-to-noise ratio

DOI: 10.3233/XST-17301

Citation: Journal of X-Ray Science and Technology, vol. 25, no. 4, pp. 711-720, 2017