bluuebunny/crossref_metadata_2025_split huggingface dataset:
Iterative CT reconstruction via minimizing adaptively reweighted	total variation
Authors: Zhu Lei , Niu Tianye , Petrongolo Michael 
Published: December 2019

BACKGROUND: Iterative reconstruction via total variation (TV) minimization has demonstrated great successes in accurate CT imaging from under-sampled projections. When projections are further reduced, over-smoothing artifacts appear in the current reconstruction especially around the structure boundaries. OBJECTIVE: We propose a practical algorithm to improve TV-minimization based CT reconstruction on very few projection data. METHOD: Based on the theory of compressed sensing, the L-0 norm approach is more desirable to further reduce the projection views. To overcome the computational difficulty of the non-convex optimization of the L-0 norm, we implement an adaptive weighting scheme to approximate the solution via a series of TV minimizations for practical use in CT reconstruction. The weight on TV is initialized as uniform ones, and is automatically changed based on the gradient of the reconstructed image from the previous iteration. The iteration stops when a small difference between the weighted TV values is observed on two consecutive reconstructed images. RESULTS: We evaluate the proposed algorithm on both a digital phantom and a physical phantom. Using 20 equiangular projections, our method reduces reconstruction errors in the conventional TV minimization by a factor of more than 5, with improved spatial resolution. CONCLUSIONS: By adaptively reweighting TV in iterative CT reconstruction, we successfully further reduce the projection number for the same or better image quality.
Impact of physician practice on patient radiation dose during CT	guided biopsy procedures
Authors: Weir Victor J. , Zhang Jie , Bruner Angela P. 
Published: December 2019

PURPOSE: Patient radiation dose during Computed Tomography (CT) guided biopsy procedures is determined by both acquisition technical parameters and physician practice. The potential effect of the physician practice is of concern. This study is to investigate the effects of those intangibles on patient radiation dose. METHODS: Patient radiation dose from 252 patients who underwent CT guided biopsy from 2009 to 2010 were retrospectively studied. Ten physicians who used conventional intermittent shots, low mA dose saving feature, or both were included in the study. The patient dose reports were retrieved and the total dose length products (DLPs) were analyzed. Linear regression analysis performed between various variables and reported dose. Patient detriment index (PDI) was developed, which sets threshold (standard of practice) for comparing physician practice with their peers. Odds ratio was calculated to determine odds of a group of patients receiving dose above threshold when compared to another group. RESULTS: Median DLP among ten physicians was 1194 mGy-cm. There was a significant difference (p< 0.01) between reported DLPs doses when physicians used dose saving feature vs. when feature not used (539.8 ± 169.4 mGy-cm vs. 1269.7 ± 659.0 mGy-cm). In general, physicians who used dose saving feature had lower relative PDIs (< 1) compared to the PDIs (> 1) without the dose feature. Odds ratio estimate of 7.7 at 95% confidence level indicates that the odds of a group receiving a high dose depends on practitioner. CONCLUSION: Adjustments of practice habits, use of dose saving features or both may be needed to improve patient care for CT biopsy.
Theoretical modeling of mobile target broadening in helical and	axial computed tomographic imaging
Authors: Ali Imad , Jackson Steven , Alsbou Nesreen , Ahmad Salahuddin 
Published: December 2019

PURPOSE: To investigate variations in mobile target length induced by sinusoidal motion in helical (HCT) and axial CT (ACT) imaging. A mathematical model was derived that predicts the measured broadening of the apparent lengths of mobile targets and its dependence on motion parameters, target size, and imaging couch speed in CT images. MATERIALS AND METHODS: Three mobile targets of differing lengths and sizes were constructed of tissue-equivalent gel material and embedded into artificial lung phantom. Respiratory motion was mimicked with a mobile phantom that moves in one-dimension along the superior-inferior direction with sinusoidal motion patterns. A mathematical model was derived to predict quantitatively the variations of apparent lengths for mobile targets and its dependence on phantom and imaging couch motion parameters in HCT and ACT. The model predictions were verified by length measurements of the mobile phantom targets that were imaged with the different motion patterns using CT imaging. RESULTS: The measured lengths of mobile targets enlarged or shrunk depending on the phantom motion parameters that include phantom speed, amplitude, frequency, phase and speed of the imaging couch. The target length variations were significant where some targets doubled lengths or shrunk to less than half of their actual length. The apparent lengths of mobile targets decreased if the target was moving in the same direction as the imaging couch motion and increased if the mobile target was moving opposed to imaging couch in both HCT and ACT. The model predicts well the variations in the mobile target apparent lengths and their dependence on the motion parameters. CONCLUSION: The measured and model variations of apparent lengths of mobile targets are considerable and may affect the accuracy of tumor volumes obtained from HCT and ACT. This mathematical model provides a method to quantitatively assess the length variations of mobile targets and their dependence on motion parameters of the phantom and imaging system which may have potential applications in the fields of diagnostic imaging and radiotherapy.
Study on image processing of panoramic X-ray using deviation	improvement software
Authors: Kim Tae-Gon , Lee Yang-Sun , Kim Young-Pyo , Park Yong-Pil , Cheon Min-Woo 
Published: December 2019

Utilization of panoramic X-ray device is getting wider. Panoramic X-ray has low resolution than general X-ray device and it occurs to distortion by deviation of image synthesis. Due to structural problems, it has been used restrictively to identify of tooth structure, not for whole head. Therefore, it designed and produced panoramic X-ray device which is possible to diagnostic coverage can be extended and had to be adjusted interval control between X-ray generator and image processing for whole of Maxillofacia's diagnosis. Produced panoramic X-ray device is composed basically of short image synthesis. In addition, it was confirmed the results by used the device which was applied deviation of the brightness of the image, filter to improve the location of the deviation and interpolation method. In this study, it was used 13 images including the front. It occurs to brightness deviation, position deviation, and geometric correction when synthesis of image, but it had been solved by deviation improvement software and a change of CCD camera's scan line which is used for image acquisition. Therefore, it confirmed expansion possibility of utilization range to commonly used panoramic X-ray device.
Combined multi-kernel head computed tomography images optimized	for depicting both brain parenchyma and bone
Authors: Takagi Satoshi , Nagase Hiroyuki , Hayashi Tatsuya , Kita Tamotsu , Hayashi Katsumi , Sanada Shigeru , Koike Masayuki 
Published: December 2019

BACKGROUND: The hybrid convolution kernel technique for computed tomography (CT) is known to enable the depiction of an image set using different window settings. OBJECTIVE: Our purpose was to decrease the number of artifacts in the hybrid convolution kernel technique for head CT and to determine whether our improved combined multi-kernel head CT images enabled diagnosis as a substitute for both brain (low-pass kernel-reconstructed) and bone (high-pass kernel-reconstructed) images. METHODS: Forty-four patients with nondisplaced skull fractures were included. Our improved multi-kernel images were generated so that pixels of >100 Hounsfield unit in both brain and bone images were composed of CT values of bone images and other pixels were composed of CT values of brain images. Three radiologists compared the improved multi-kernel images with bone images. RESULTS: The improved multi-kernel images and brain images were identically displayed on the brain window settings. All three radiologists agreed that the improved multi-kernel images on the bone window settings were sufficient for diagnosing skull fractures in all patients. CONCLUSIONS: This improved multi-kernel technique has a simple algorithm and is practical for clinical use. Thus, simplified head CT examinations and fewer images that need to be stored can be expected.
Low-mAs X-ray CT image reconstruction by adaptive-weighted	TV-constrained penalized re-weighted least-squares
Authors: Liu Yan , Ma Jianhua , Zhang Hao , Wang Jing , Liang Zhengrong 
Published: December 2019

BACKGROUND: The negative effects of X-ray exposure, such as inducing genetic and cancerous diseases, has arisen more attentions. OBJECTIVE: This paper aims to investigate a penalized re-weighted least-square (PRWLS) strategy for low-mAs X-ray computed tomography image reconstruction by incorporating an adaptive weighted total variation (AwTV) penalty term and a noise variance model of projection data. METHODS: An AwTV penalty is introduced in the objective function by considering both piecewise constant property and local nearby intensity similarity of the desired image. Furthermore, the weight of data fidelity term in the objective function is determined by our recent study on modeling variance estimation of projection data in the presence of electronic background noise. RESULTS: The presented AwTV-PRWLS algorithm can achieve the highest full-width-at-half-maximum (FWHM) measurement, for data conditions of (1) full-view 10 mA acquisition and (2) sparse-view 80 mA acquisition. In comparison between the AwTV/TV-PRWLS strategies and the previous reported AwTV/TV-projection onto convex sets (AwTV/TV-POCS) approaches, the former can gain in terms of FWHM for data condition (1), but cannot gain for the data condition (2). CONCLUSIONS: In the case of full-view 10 mA projection data, the presented AwTV-PRWLS shows potential improvement. However, in the case of sparse-view 80 mA projection data, the AwTV/TV-POCS shows advantage over the PRWLS strategies.
Impact of rare earth element added filters on the X-ray beam	spectra: A Monte Carlo approach
Authors: Eskandarlou Amir , Jafari Amir Abbas , Mohammadi Mohammad , Zehtabian Mehdi , Faghihi Reza , Shokri Abbas , Pourolajal Jalal 
Published: December 2019

The effectiveness of added filters including conventional and rare earth materials for dental radiography tasks was investigated using a simulation approach. Current study focuses on the combination of a range of various filters to investigate the reduction of radiation absorbed dose and improving the quality of a radiography image. To simulate the X-ray beam spectrum, a MCNP5 code was applied. Relative intensity, beam quality, and mean energy were investigated for a typical dental radiography machine. The impact of different rare-earth materials with different thicknesses and tube voltages on the X-ray spectrum was investigated. For Aluminum as a conventional filter, the modeled X-ray spectra and HVL values were in a good agreement with those reported by IPEM. The results showed that for a 70 kVp voltage, with an increase of the thickness and atomic number of a given added filters, an increase of HVL values were observed. However, with the increase of the attenuator thickness, X-ray beam intensity decreases. For mean energy, different results were observed. It was also found that rare earth made filters reduce high energy X-ray radiation due to k-edge absorption. This leads to an ideal beam for intra-oral radiography tasks. However, as a disadvantage of rare earth added filters, the reduction of the tube output levels should also be considered.
Detection of uric acid depositing in tophaceous gout using a new	dual energy spectral CT technology
Authors: Li Xiaohu , Wang Xu , Yu Yonqqiang , Liu Bin , Cai Jing , Xia Li , Luo Li , Wang Wanqin , Ding Qianyun , Zhang Chao , Wang Jie 
Published: December 2019

OBJECTIVE: To assess the feasibility and diagnostic value of detecting uric acid depositing among patients with tophaceous gout using a dual energy CT based Gemstone spectral imaging (GSI) technology for qualitative analysis of uric acid. METHODS: Thirty one patients with clinically detectable tophaceous gout and 10 healthy volunteers underwent Discovery CT 750 HD scan with GSI mode. We selected four case groups of tophi, muscles, cortical bone, and cancellous bone. Each has a region of interest (ROI) of 10 mm diameter. We then analyzed and compared the difference of CT imaging spectroscopy quantitative parameters including concentration of uric acid, calcium, and water levels. The univariate analysis of variance and independent samples t-test were applied in data analyses. RESULTS: In case group of tophi base substance, the concentration levels were 1268.8 ± 32.2 mg/cm $^3$ for uric acid (Ca), 19.4 ± 9.5 mg/cm $^3$ for calcium (uric acid), 10.8 ± 9.5 mg/cm $^3$ for calcium (water), and 1171.0 ± 26.8 mg/cm $^3$ for water (calcium), respectively. In cortical bone case group, the four base substance concentration levels changed to 1333.6 ± 83.8 mg/cm $^3$ , 271.1 ± 85.0 mg/cm $^3$ , 262.6 ± 85.4 mg/cm $^3$ , and 1230.8 ± 77.0 mg/cm $^3$ . In muscles case group, the four base substance concentration levels were 1143.5 ± 15.7 mg/cm $^3$ , 12.3 ± 5.0 mg/cm $^3$ , 4.4 ± 1.9 mg/cm $^3$ , and 1054.1 ± 14.6 mg/cm $^3$ . Finally, in cancellous bone case group, the corresponding base substance concentration became 1070.9 ± 26.4 mg/cm $^3$ , 85.1 ± 46.9 mg/cm $^3$ , 77.4 ± 46.7 mg/cm $^3$ , and 988.0 ± 23.4 mg/cm^3. Except tophi and muscle differences between Calcium (uric acid) concentration and differences in Calcium (water) concentration, which were not significantly different (p> 0.29), the remaining group pairwise comparisons of the parameters were significantly different (p < 0.05). CONCLUSION: Dual-energy spectral CT can detect gout tophi within the peripheral joints of the patients. The quantitative measurement of the tophi concentration provides a new imaging method for quantitatively monitoring clinical outcomes of tophi.
Fast analytical scatter estimation using graphics processing	units
Authors: Ingleby Harry , Lippuner Jonas , Rickey Daniel W. , Li Yue , Elbakri Idris 
Published: December 2019

PURPOSE: To develop a fast patient-specific analytical estimator of first-order Compton and Rayleigh scatter in cone-beam computed tomography, implemented using graphics processing units. METHODS: The authors developed an analytical estimator for first-order Compton and Rayleigh scatter in a cone-beam computed tomography geometry. The estimator was coded using NVIDIA's CUDA environment for execution on an NVIDIA graphics processing unit. Performance of the analytical estimator was validated by comparison with high-count Monte Carlo simulations for two different numerical phantoms. Monoenergetic analytical simulations were compared with monoenergetic and polyenergetic Monte Carlo simulations. Analytical and Monte Carlo scatter estimates were compared both qualitatively, from visual inspection of images and profiles, and quantitatively, using a scaled root-mean-square difference metric. Reconstruction of simulated cone-beam projection data of an anthropomorphic breast phantom illustrated the potential of this method as a component of a scatter correction algorithm. RESULTS: The monoenergetic analytical and Monte Carlo scatter estimates showed very good agreement. The monoenergetic analytical estimates showed good agreement for Compton single scatter and reasonable agreement for Rayleigh single scatter when compared with polyenergetic Monte Carlo estimates. For a voxelized phantom with dimensions 128 × 128 × 128 voxels and a detector with 256 × 256 pixels, the analytical estimator required 669 seconds for a single projection, using a single NVIDIA 9800 GX2 video card. Accounting for first order scatter in cone-beam image reconstruction improves the contrast to noise ratio of the reconstructed images. CONCLUSION: The analytical scatter estimator, implemented using graphics processing units, provides rapid and accurate estimates of single scatter and with further acceleration and a method to account for multiple scatter may be useful for practical scatter correction schemes.
PENGARUH KUALITAS PRODUK DAN KUALITAS PELAYANAN TERHADAP KEPUASAN KONSUMEN PT. RADEKATAMA PIRANTI NUSA
Authors: Lesmana Rosa 
Published: December 2019

Abstrak Penelitian ini bertujuan untuk mengetahui pengaruh kualitas produk dan kualitas pelayanan terhadap kepuasan konsumen PT. Radekatama Piranti Nusa. Penelitian ini menggunakan metode asosiatif deskriptif dengan pendekatan kuantitatif. Populasinya adalah konsumen yang melakukan pembelian selama tahun 2017 sebanyak 638 konsumen dan sampel diambil sebanyak 86 orang. Perhitungan menggunakan SPSS. Hasil penelitian menunjukkan bahwa kualitas produk dan kualitas pelayanan berpengaruh positif terhadap kepuasan pelanggan dengan persamaan regresi Y = 15,009 + 0,294X1 + 0,422X2. Kontribusi pengaruh kualitas produk, kualitas pelayanan dan kepuasan pelanggan secara simultan adalah sebesar 44,8%, nilai F hitung lebih besar dari F tabel atau (39,285 > 2,700), dengan signifikansi 0,000 < 0,05.terdapat pengaruh positif dan signifikan secara simultan antara kualitas produk dan kualitas pelayanan terhadap kepuasan konsumen
PENGARUH KUALITAS PELAYANAN TERHADAP LOYALITAS DONATUR PADA YAYASAN YATIM INDONESIA CABANG GRAHA RAYA BINTARO
Authors: Haryoko Ugeng Budi , Dina Rahma 
Published: December 2019

Penelitian ini bertujuan untuk mengetahui pengaruh kualitas pelayanan terhadap loyalitas donator (studi kasus pada Yayasan Sahabat Yatim Indonesia cabang Graha Raya Bintaro)Metode penelitian yang digunakan penulis adalah deskriptif kuantitatif melalui wawancara dan observasi langsung. Metode analisis yang digunakan uji validitas, uji reabilitas, uji koefisien regresi sederhana, uji koefisien determinasi, uji signifikansi (uji t). Populasi yang digunakan berjumlah 9586 responden dan sampelnya sejumlah 100 responden.Hasil penelitian menunjukkan bahwa Koefisien korelasi didapatkan hasil sebesar 0,280, artinya ada pengaruh yang Rendah antara Kualitas Pelayanan (Variabel X) terhadap Loyalitas Pelanggan (Variabel Y). Dan jika di lihat dari Analisis Koefisien Determinasi didapat hasil 8% yang artinya pengaruh kualitas pelayanan sebesar 8% terhadap loyalitas donator sedangkan 92% di pengaruhi oleh faktor lain yang memang tidak diteliti dalam penelitian ini, dan jika di lihat dari Analisis Regresi Linier Sederhana Y = 22,415 + 0,215 X, serta hasil Uji Hipotesis mendapatkan nilai t hitung lebih besar dari t tabel sebesar 2,8855 > 1,6605 maka Ho di tolak dan Ha di terima yang artinya ada pengaruh yang signifikan antara kualitas pelayanan terhadap loyalitas donatur pada Yayasan Sahabat Yatim Indonesia Cabang Graha Raya Bintaro
The Diagnostic Value of Forced Expiratory Time
Authors: Wali Siraj O. 
Published: November 2019

Objective: Airway obstruction can be clinically quantified at the bedside by measuring the time taken for forced expiration. The aim of this study was to examine the accuracy of the forced expiratory time in detecting airflow limitation, and small airway disease when compared with simple spirometry as a gold standard test.
Method: Simple spirometry and forced expiratory time were performed on 201 subjects (age range; 12-81 years), referred to a pulmonary function laboratory at a tertiary care hospital. The diagnostic accuracy of forced expiratory time and its correlation with spirometric parameters were tested. Forced expiratory time > 6 seconds was regarded as abnormal, and the ratio of forced expiratory volume in the first second to forced vital capacity of < 70% was considered indicative of an airflow limitation.
Results: Forced expiratory time was found to correlate weakly with spirometric parameters. Forced expiratory time at a cut-off value of => 6 seconds had a sensitivity of 61% and a specificity of 79% in predicting obstructive airway disease when compared with simple spirometry. On the other hand, the sensitivity and the specificity of forced expiratory time in predicting small airway disease were 47% and 86%, respectively.
Conclusion: Forced expiratory time does not correlate well with all parameters of a simple spirometry. Its sensitivity and specificity for detecting airflow limitation and small airway disease were not high enough to be used as a diagnostic test. However, it may be effective enough to be utilized to confirm the diagnosis of small airway disease.
Efeito agudo dos alongamentos estático e FNP sobre o desempenho da força dinâmica máxima
Authors: Gomes Thiago Matassoli 
Published: December 2019

O objetivo deste estudo foi verifi car o efeito agudo dos alongamentos estático passivo e facilitação neuromuscular proprioceptiva sobre o desempenho da força dinâmica máxima. O estudo foi realizado com 21 voluntários do sexo masculino (24,1 ± 1,7 anos) treinados em força há pelo menos dois anos. Para auferição da força dinâmica máxima foi utilizado o protocolo de teste e re-teste de uma repetição máxima (1RM) no supino horizontal. Todos os sujeitos participaram de todas as situações experimentais, sendo: a) alongamento estático + 1RM (EP); b) alongamento FNP + 1RM (FNP); c) teste de 1RM sem alongamento (GC). A ordem de participação nos protocolos experimentais foi determinada de forma aleatória. O resultado da ANOVA com medidas repetidas mostrou diferenças significativas com relação í situação controle, tanto na situação EP (p = 0,00) quanto na situação FNP (p = 0,00). Onde a média nas condições experimentais EP (95 ± 12,3 kg) e FNP (92 ± 11,2 kg) foi significativamente menor do que GC (99,2 ± 11,4 kg). Conclui-se que uma sessão de alongamento estático ou FNP executada imediatamente antes do treinamento de força provocou uma diminuição do desempenho.Palavras-chave: flexibilidade, teste de 1 RM, rendimento, treinamento concorrente.
Relação entre obesidade e hábitos de vida em escolares da rede pública e privada da cidade de Santa Rosa/RS
Authors: De Carvalho Warley Gomes 
Published: December 2019

O objetivo do presente estudo foi relacionar os hábitos de vida de escolares com a obesidade. Participaram 314 adolescentes e pré-adolescentes, com idades entre 10 e 17 anos, sendo 156 do sexo feminino e 158 do sexo masculino, matriculados no ensino fundamental em escolares de quatro escolas de Santa Rosa (RS) sendo duas da rede pública e duas da rede privada. A pesquisa utilizou como instrumentos a medida do í­ndice de massa corporal (IMC) e um questionário estruturado sobre hábitos de vida. Para a realização dos cálculos estatí­sticos, foi utilizado o teste qui-quadrado, para testar a distribuição de freqüências. Do total de alunos, 231 (73,6%) foram classificados como tendo IMC normal e 83 (26,4%) como tendo IMC apresentando sobrepeso. Não foi encontrada diferença estatisticamente significante entre as escolas em relação a ver TV (p = 0,37), lazer fora de casa (p = 0,46) e IMC (p = 0,14). Por outro lado, encontrou-se diferença estatisticamente significante entre as escolas no tempo destinado ao videogame (p = 0,02) e í prática de atividades fí­sicas sistematizadas (p = 0,01), sendo maior nas escoladas da rede privada. Considerada isoladamente, a prática de atividades fí­sicas pelos alunos das escolas particulares não é um fator suficiente de controle do sobrepeso ou da obesidade.Palavras-chave: sobrepeso, atividade fí­sica, sedentarismo.