Zeitschriftenartikel: „Diffusion CT“

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Da Silva, Marly Terezinha Quadri Simões, und Wellington Mazer. „Diffusion coefficient and tortuosity: Brownian Motion“. CONTRIBUCIONES A LAS CIENCIAS SOCIALES 16, Nr. 9 (28.09.2023): 18281–302. http://dx.doi.org/10.55905/revconv.16n.9-264.

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The objective of this research is to determine the chloride ion diffusion through Brownian motion using images. The research also aims at the search for diffusional physical tortuosity due to Brownian motion to understand the transport flow of the chloride ion. Through micro-CT scanned images of concrete samples, a 3D reconstruction is performed for the representative element and define its microscopic properties. The implementation of the Brownian motion of the chloride ion particles in the porous network of the representative element considered the initial diffusion coefficient defined by the Stokes-Einstein equation. The diffusion coefficient is an important parameter for predicting the depth of attack of the chloride ion and its displacement due to Brownian motion helps to define the tortuosity of this diffusive transport. The research used computational modeling with MATLAB® software. The results show diffusion due to Brownian motion and tortuousness.

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Guo, Huimin, Zhiwen Zhang, Li Wang, Shuzhan Yao, Shuaishuai Xu, Shulin Ma und Songtao Liu. „Diagnostic Significance of 18F-FDG PET/CT Imaging Coupled with Magnetic Resonance Imaging of the Entire Body for Bone Metastases“. Contrast Media & Molecular Imaging 2022 (27.09.2022): 1–7. http://dx.doi.org/10.1155/2022/7717398.

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Objective. To see if 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) imaging paired with MR diffusion imaging can help doctors diagnose bone metastases. Methods. From September 2020 to December 2021, a total of 30 individuals with probable bone metastases were recruited for the trial. With an average interval of four days, MAGNETIC resonance whole-body diffusion imaging (MR whole-body diffusion imaging) was performed on each of the 30 patients who had 18F-FDG PET/CT. The SUVmax values of the group with bone metastases were compared to those of the group without bone metastases. In this study, 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combination were examined. The researchers compared the results when 18F-FDG PET/CT imaging, whole-body MRI diffusion scans, and their combination indicated abnormal bone lesions. By comparing the diagnostic efficacy of 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combination, as well as accuracy, sensitivity, and specificity, the three techniques for diagnosing bone metastases will be evaluated for diagnostic usefulness. Results: the SUV max values of patients with bone metastases were significantly different from those of patients without bone metastases, as determined by 18F-FDG PET/CT imaging ( P < 0.05). Using 18F-FDG PET/CT imaging, MR whole-body diffusion imaging, and their combined detection of aberrant bone lesions in various areas, we found statistically significant differences. Conclusion. The use of 18F-FDG PET/CT imaging in conjunction with MR whole-body diffusion imaging in the diagnosis of bone metastases can be very helpful.

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Sigismondi, Paolo. „Exploring Translation Gaps: The Untranslatability and Global Diffusion of “Cool”“. Communication Theory 28, Nr. 3 (16.04.2018): 292–310. http://dx.doi.org/10.1093/ct/qtx007.

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Chae, Baek, Chang shik Choi, Seung-Hwa Kang und Yun-Cheol Heo. „Diffusion of television, wax and wane of community and family bond“. Communication Theories 14, Nr. 4 (31.12.2018): 139–82. http://dx.doi.org/10.20879/ct.2018.14.4.139.

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Chae, Baek, Seung-Hwa Kang und Yun-Cheol Heo. „Diffusion of telephone and changes in interpersonal relationship: An oral history study“. Communication Theories 15, Nr. 3 (30.09.2019): 105–51. http://dx.doi.org/10.20879/ct.2019.15.3.105.

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Morris, N. „A Comparative Analysis of the Diffusion and Participatory Models in Development Communication“. Communication Theory 13, >2 (01.05.2003): 225–48. http://dx.doi.org/10.1093/ct/13.2.225.

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Okazumi, Shinichi, Gaku Ohira, Koichi Hayano, Tomoyoshi Aoyagi, Shunsuke Imanishi und Hisahiro Matsubara. „Novel Advances in Qualitative Diagnostic Imaging for Decision Making in Multidisciplinary Treatment for Advanced Esophageal Cancer“. Journal of Clinical Medicine 13, Nr. 2 (22.01.2024): 632. http://dx.doi.org/10.3390/jcm13020632.

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Background: Recently, neoadjuvant therapy and the succeeding surgery for advanced esophageal cancer have been evaluated. In particular, the response to the therapy has been found to affect surgical outcomes, and thus a precise evaluation of treatment effect is important for this strategy. In this study, articles on qualitative diagnostic modalities to evaluate tumor activities were reviewed, and the diagnostic indices were examined. Methods: For prediction of the effect, perfusion CT and diffusion MRI were estimated. For the histological response evaluation, perfusion CT, diffusion-MRI, and FDG-PET were estimated. For downstaging evaluation of T4, tissue-selective image reconstruction using enhanced CT was estimated and diagnostic indices were reviewed. Results: The prediction of the effect using perfusion CT with ‘pre CRT blood flow’ and diffusion MRI with ‘pre CRT ADC value’; the estimation of the histological response using perfusion CT with ‘post CRT blood flow reduction, using diffusion MRI with ‘post CRT ADC increasing’, and using FDG-PET with ‘post CRT SUV reduction’; and the downstaging evaluation of T4 using CT image reconstruction with ‘fibrous changed layer’ were performed well, respectively. Conclusions: Qualitative imaging modalities for prediction or response evaluation of neoadjuvant therapy for progressive esophageal cancer were useful for the decision making of the treatment strategy of the multidisciplinary treatment.

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Kim, Su-Beom, Soo Jin Song, Yeong Hyoen Yoo und Dar Oh Lim. „International Comparative Analysis of Advanced Diagnostic Imaging Equipment Demand Characteristics Using the Bass Diffusion Model“. Journal of Health Informatics and Statistics 49, Nr. 1 (28.02.2024): 27–34. http://dx.doi.org/10.21032/jhis.2024.49.1.27.

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Objectives: This paper proposed the direction of future supply and demand management policies through demand prediction and demand characteristics analysis of advanced diagnostic imaging equipment using new medical technology.Methods: This study used the Bass Diffusion Model to analyze demand characteristics for advanced diagnostic imaging equipment. Derived diffusion coefficients were applied for medium to long-term demand predictions (2021-2050). Parameter estimation employed non-linear regression analysis (SPSS 27.0). Demand characteristics were further analyzed using the ratio of the Bass model’s innovation to imitation coefficients for each country and device.Results: Comparing the imitation coefficients (q/p ratio) for computed tomography (CT) and magnetic resonance imaging (MRI) among South Korea, the United States, and Japan, South Korea has the highest q/p ratio for both CT and MRI. This implies that the influence of opinion leaders and group pressure is relatively more significant in South Korea, particularly in CT purchases. In the demand prediction results, South Korea’s q/p ratio for CT and MRI is notably larger, suggesting that institutional pressures and collective decision-making, rather than individual clinical decisions, play a significant role in the purchase of advanced diagnostic imaging Equipment. The q/p ratio for advanced diagnostic imaging Equipment in South Korea is higher than in other countries, reflecting a large power distance in the adoption of these technologies.Conclusions: This study utilizes the Bass Diffusion Model to predict the demand for advanced diagnostic imaging equipment in South Korea, Japan, and the United States. Findings highlight that imitation, not innovation, is the main driver of diffusion, with South Korea showing a faster adoption rate for CT and MRI. The study identifies factors influencing diffusion in South Korea, noting the impact of the quantity system on CT and the absence of influence on MRI. CT diffusion is positively linked to the quantity-based payment system, while MRI remains unaffected.

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Demeestere, Jelle, Carlos Garcia-Esperon, Pablo Garcia-Bermejo, Fouke Ombelet, Patrick McElduff, Andrew Bivard, Mark Parsons und Christopher Levi. „Evaluation of hyperacute infarct volume using ASPECTS and brain CT perfusion core volume“. Neurology 88, Nr. 24 (17.05.2017): 2248–53. http://dx.doi.org/10.1212/wnl.0000000000004028.

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Objective:To compare the accuracy of Alberta Stroke Program Early Computed Tomography Score (ASPECTS) and CT perfusion to detect established infarction in acute anterior circulation stroke.Methods:We performed an observational study in 59 acute anterior circulation ischemic stroke patients who underwent brain noncontrast CT, CT perfusion, and MRI within 100 minutes from CT imaging. ASPECTS scores were calculated by 4 blinded vascular neurologists. The accuracy of ASPECTS and CT perfusion core volume to detect an acute MRI diffusion lesion of ≥70 mL was evaluated using receiver operating characteristics analysis and optimum cutoff values were calculated using Youden J.Results:Median ASPECTS score was 8 (interquartile range [IQR] 5–9). Median CT perfusion core volume was 22 mL (IQR 10.4–71.9). Median MRI diffusion lesion volume was 24.5 mL (IQR 10–63.9). No significant difference was found between the accuracy of CT perfusion and ASPECTS (c statistic 0.95 vs 0.87, p value for difference = 0.17). The optimum ASPECTS cutoff score to detect a diffusion-weighted imaging lesion ≥70 mL was <7 (sensitivity 0.74, specificity 0.86, Youden J = 0.60) and the optimum CT perfusion core volume cutoff was ≥50 mL (sensitivity 0.86, specificity 0.97, Youden J = 0.84). The CT perfusion core lesion covered a median of 100% (IQR 86%–100%) of the acute MRI lesion volume (Pearson R = 0.88; R2 = 0.77).Conclusions:We found no significant difference between the accuracy of CT perfusion and ASPECTS to predict hyperacute MRI lesion volume in ischemic stroke.

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Sato, Akira, und Koichi Ikeda. „Visualization of diffusion phenomena in porous media by means of X-ray computed tomography (CT) scanning“. Canadian Geotechnical Journal 52, Nr. 10 (Oktober 2015): 1448–56. http://dx.doi.org/10.1139/cgj-2014-0451.

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The migration of water and contamination materials in rock structures is a significant issue in projects that utilize deep underground locations such as “carbon-dioxide capture and storage” (CCS) and disposal of high-level nuclear waste. These phenomena are also important in the area of preservation of stone structures of cultural heritage signficance, as such stone structures are usually located outside, exposed to wind and rain. The migration of contamination materials in the underground environment, especially in porous rock mass, is governed mainly by water permeation and diffusion. In this study, one-dimensional diffusion testing was conducted and the process in the porous materials was visualized by X-ray computed tomography (CT) scanning. Diffusion is the process caused by the concentrate or density gradient, and is a suitable phenomenon for X-ray CT analysis. In this paper, information related to diffusion is extracted from X-ray CT image data and the distribution of concentration is estimated. From the obtained density distribution, diffusion coefficients are evaluated. One-dimensional permeation tests were also conducted and intrinsic permeabilities of porous materials are evaluated, then the relation between diffusion coefficients and intrinsic permeability is discussed.

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Savushkina, O. I., A. V. Cherniak, E. V. Kryukov, I. Ts Kulagina, M. V. Samsonova, E. N. Kalmanova und K. A. Zykov. „Pulmonary function after COVID-19 in early convalescence phase“. Medical alphabet, Nr. 25 (26.10.2020): 7–12. http://dx.doi.org/10.33667/2078-5631-2020-25-7-12.

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Pulmonary function after COVID-19 in early convalescence phase. The aim of the study is to investigate the influence of Coronavirus disease 2019 (COVID-19) on pulmonary function in early convalescence phase.Materials and methods. The study included 44 patients (35 male) after COVID-19 without concomitant bronchopulmonary pathology, with a median age of 47.5 years. All patients underwent standard pulmonary function tests (PFTs): spirometry, body plethysmography, diffusion test. Besides, dyspnea on the mMRC scale was assessed, oxygen saturation level (SpO2 ) was measured. Depending on degree of lung damage determined using high-resolution computed tomography (CT), the patients were divided into 2 groups: group 1 (22 patients) — CT 1 and CT 2, group 2 (22 patients) — CT 3 and CT 4.Results. The medians of standard PFTs parameters were in normal values. However, there were statistically significant differences between groups: VC, FVC, FEV1 and TLC were lower in second group. Diffusing capacity was reduced in 52% of patients. Statistical significant correlations were established between lung damage by CT and the parameters of VC, FVC, FEV1 , TLC, IC and DLCO.Conclusion. The degree of functional disorders of lungs depended on the extent of abnormal CT. Impaired diffusing capacity were detected in more than half of the COVID-19 patients in early convalescence phase.

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Haddock, Cynthia Carter, und James W. Begun. „The Diffusion of Two Diagnostic Technologies among Hospitals in New York State“. International Journal of Technology Assessment in Health Care 4, Nr. 4 (Oktober 1988): 593–600. http://dx.doi.org/10.1017/s0266462300007649.

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Using combined data from an independent survey by the American Hospital Association and the State of New York, the diffusion of two diagnostic technologies–the automated chemistry analyzer and the computed tomography (CT) scanner–among hospitals in New York State was analyzed. A linearized form of the logistic function was estimated using cumulative diffusion data for each. Diffusion patterns of both technologies fit the logistic curve well, with the coefficient of diffusion for the CT scanner being greater than that for the automated analyzer. Further analysis examined characteristics of early adopters of each technology. Similar hospital characteristics (e.g., high volume of admissions and medical school affiliation) were important in explaining early adoption of both technologies.

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Chen, Leqing, Feihong Wu, Jia Huang, Jinrong Yang, Wenliang Fan, Zhuang Nie, Hongwei Jiang, Jiazheng Wang, Wenfang Xia und Fan Yang. „Well-Aerated Lung and Mean Lung Density Quantified by CT at Discharge to Predict Pulmonary Diffusion Function 5 Months after COVID-19“. Diagnostics 12, Nr. 12 (23.11.2022): 2921. http://dx.doi.org/10.3390/diagnostics12122921.

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Background: The aim of this study was to explore the predictive values of quantitative CT indices of the total lung and lung lobe tissue at discharge for the pulmonary diffusion function of coronavirus disease 2019 (COVID-19) patients at 5 months after symptom onset. Methods: A total of 90 patients with moderate and severe COVID-19 underwent CT scans at discharge, and pulmonary function tests (PFTs) were performed 5 months after symptom onset. The differences in quantitative CT and PFT results between Group 1 (patients with abnormal diffusion function) and Group 2 (patients with normal diffusion function) were compared by the chi-square test, Fisher’s exact test or Mann–Whitney U test. Univariate analysis, stepwise linear regression and logistic regression were used to determine the predictors of diffusion function in convalescent patients. Results: A total of 37.80% (34/90) of patients presented diffusion dysfunction at 5 months after symptom onset. The mean lung density (MLD) of the total lung tissue in Group 1 was higher than that in Group 2, and the percentage of the well-aerated lung (WAL) tissue volume (WAL%) of Group 1 was lower than that of Group 2 (all p < 0.05). Multiple stepwise linear regression identified only WAL and WAL% of the left upper lobe (LUL) as parameters that positively correlated with the percent of the predicted value of diffusion capacity of the lungs for carbon monoxide (WAL: p = 0.002; WAL%: p = 0.004), and multiple stepwise logistic regression identified MLD and MLDLUL as independent predictors of diffusion dysfunction (MLD: OR (95%CI): 1.011 (1.001, 1.02), p = 0.035; MLDLUL: OR (95%CI): 1.016 (1.004, 1.027), p = 0.008). Conclusion: At five months after symptom onset, more than one-third of moderate and severe COVID-19 patients presented with diffusion dysfunction. The well-aerated lung and mean lung density quantified by CT at discharge could be predictors of diffusion function in convalesce.

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Hussain, Omar, Mayank Kaushal, Nitin Agarwal, Shekar Kurpad und Saman Shabani. „The Role of Magnetic Resonance Imaging and Computed Tomography in Spinal Cord Injury“. Life 13, Nr. 8 (03.08.2023): 1680. http://dx.doi.org/10.3390/life13081680.

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Traumatic injuries of the spine are associated with long-term morbidity and mortality. Timely diagnosis and appropriate management of mechanical instability and spinal cord injury are important to prevent further neurologic deterioration. Spine surgeons require an understanding of the essential imaging techniques concerning the diagnosis, management, and prognosis of spinal cord injury. We present a review in the role of computed tomography (CT) including advancements in multidetector CT (MDCT), dual energy CT (DECT), and photon counting CT, and how it relates to spinal trauma. We also review magnetic resonance imaging (MRI) and some of the developed MRI based classifications for prognosticating the severity and outcome of spinal cord injury, such as diffusion weighted imaging (DWI), diffusion tractography (DTI), functional MRI (fMRI), and perfusion MRI.

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Gärtner, Friederike, Julia Forstenpointner, Birgit Ertl-Wagner, Babak Hooshmand, Christian Riedel und Olav Jansen. „CT and MRI Findings in Cerebral Aspergilloma“. RöFo - Fortschritte auf dem Gebiet der Röntgenstrahlen und der bildgebenden Verfahren 190, Nr. 10 (20.11.2017): 967–70. http://dx.doi.org/10.1055/s-0043-120766.

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Purpose Invasive aspergillosis usually affects immunocompromised patients. It carries a high risk of morbidity and mortality and usually has a nonspecific clinical presentation. Early diagnosis is essential in order to start effective treatment and improve clinical outcome. Materials and Methods In a retrospective search of the PACS databases from two medical centers, we identified 9 patients with histologically proven cerebral aspergilloma. We systematically analyzed CT and MRI imaging findings to identify typical imaging appearances of cerebral aspergilloma. Results CT did not show a typical appearance of the aspergillomas. In 100 % (9/9) there was a rim-attenuated diffusion restriction on MRI imaging. Multiple hypointense layers in the aspergillus wall, especially on the internal side, were detected in 100 % on T2-weighted imaging (9/9). Aspergillomas were T1-hypointense in 66 % of cases (6/9) and partly T1-hyperintense in 33 % (3/9). In 78 % (7/9) of cases, a rim-attenuated diffusion restriction was detected after contrast agent application. Conclusion Nine cases were identified. Whereas CT features were less typical, we observed the following imaging features on MRI: A strong, rim-attenuated diffusion restriction (9/9); onion layer-like hypointense zones, in particular in the innermost part of the abscess wall on T2-weighted images (9/9). Enhancement of the lesion border was present in the majority of the cases (7/9). Key points Citation Format

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Tiwari, Shailendra, und Kavkirat Kaur. „Complex diffusion regularisation-based low dose CT image reconstruction“. International Journal of Biomedical Engineering and Technology 35, Nr. 1 (2021): 37. http://dx.doi.org/10.1504/ijbet.2021.10035162.

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Kaur, Kavkirat, und Shailendra Tiwari. „Complex diffusion regularisation-based low dose CT image reconstruction“. International Journal of Biomedical Engineering and Technology 35, Nr. 1 (2021): 37. http://dx.doi.org/10.1504/ijbet.2021.112833.

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Fiebach, J. B., P. D. Schellinger, O. Jansen, M. Meyer, P. Wilde, J. Bender, P. Schramm et al. „CT and Diffusion-Weighted MR Imaging in Randomized Order“. Stroke 33, Nr. 9 (September 2002): 2206–10. http://dx.doi.org/10.1161/01.str.0000026864.20339.cb.

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Dubreuil, Julien, Jeremie Tordo, Domenico Rubello, Francesco Giammarile und Andrea Skanjeti. „Diffusion-weighted MRI and 18F-FDG-PET/CT imaging“. Nuclear Medicine Communications 38, Nr. 1 (Januar 2017): 84–90. http://dx.doi.org/10.1097/mnm.0000000000000612.

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Weiss, KL, KL Macura und A. Ahmed. „Cerebral air embolism: Diffusion MRI as adjunct to CT“. Journal of Stroke and Cerebrovascular Diseases 6, Nr. 6 (Oktober 1997): 459. http://dx.doi.org/10.1016/s1052-3057(97)80136-x.

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Vlachopoulos, Georgios, Spyros Skiadopoulos, Andreas Petropoulos, Anna Karahaliou und Lena Costaridou. „Edge-enhancing diffusion noise reduction in dual-energy CT“. Physica Medica 30 (2014): e17. http://dx.doi.org/10.1016/j.ejmp.2014.07.064.

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Bautz, James B., Joel M. Schectman, Elaine G. Elinsky und L. Gregory Pawlson. „Magnetic Resonance Imaging: Diffusion of Technology in an Ambulatory Setting“. International Journal of Technology Assessment in Health Care 8, Nr. 02 (März 1992): 301–8. http://dx.doi.org/10.1017/s0266462300013519.

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AbstractTo better understand technology diffusion in an ambulatory care setting, we analyzed adult outpatients’ use of magnetic resonance (MR) and computed tomography (CT) imaging in a group-model HMO between 1986 and 1989. The use of MR, but not CT, Increased at a rapid pace with only a small proportion of the scans being accounted for by primary care physicians.

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Jannello, Karina. „Benito Milla: un Ulises desgraciado en el Río de la Plata. De Cuadernos Internacionales a Mundo Nuevo, del socialismo libertario al humanismo antibelicista“. Catedral Tomada. Revista de crítica literaria latinoamericana 6, Nr. 11 (03.01.2019): 199–235. http://dx.doi.org/10.5195/ct/2018.359.

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The following article aims to recover the cultural management of the Spanish republican exiled in Montevideo Benito Milla between the 1950s and 1965s. Since his arrival in Montevideo, encouraged by his anarchist ideals, Milla sets up a reference space for the Uruguayan culture that is reconfiguring a humanist and anti-war left wing. Through its magazines Cuadernos Internacionales, Deslinde, Letras 62, Número (2ndep.) and Temas, but also through the editorials that he creates for the diffusion of the new talents of the Generation of 45: Deslinde and Alfa, Milla constitutes himself in a fundamental link to understand the strong expansion of Uruguayan culture in those years.

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Ruikar, Dr Sachin D., und Ms Vrushali N. Raut. „A Comparison of Filtering Techniques for Image Quality Improvement in Computed Tomography“. INTERNATIONAL JOURNAL OF COMPUTERS & TECHNOLOGY 7, Nr. 3 (10.06.2013): 670–76. http://dx.doi.org/10.24297/ijct.v7i3.3445.

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Computed Tomography (CT) is an important and most common modality in medical imaging. In CT examinations there is trade off between radiation dose and image quality. If radiation dose is decreased, the noise will unavoidably increase degrading the diagnostic value of the CT image and ifthe radiation dose is increased, the associated risk of cancer also increases especially in paediatric applications. Image filtering techniques perform image pre-processing to improve the quality of images. These techniques serve two major purposes. One is to maintain low radiation dose and another is to make subsequent phases of image analysis like segmentation or recognition easier or more effective. This paper presents the effect of noise reduction filter on CT images particularly that of anisotropic diffusion filter and Gaussian filter in combination with Prewitt operator. Anisotropic diffusion is Selective and nonlinear filtering technique which filters an image within the object boundaries and not across the edge orientation. Simulation results have shown that the anisotropic diffusion filter can effectively smooth noisy background, yet well preserve edge and fine details in the restored image. Gaussian filter smoothens the image while Prewitt operator detects the edges, so the combination of Gaussian filters and Prewitt operator works like a nonlinear filter.Thus these two filtering techniques improve an image quality and allow use of low dose CT protocol

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Sun, Yingfeng, Yixin Zhao, Hongwei Zhang und Cun Zhang. „Visualization of Gas Diffusion-Sorption in Coal: A Study Based on Synchrotron Radiation Nano-CT“. Geofluids 2020 (02.07.2020): 1–11. http://dx.doi.org/10.1155/2020/8835848.

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Gas diffusion-sorption is a critical step in coalbed methane (CBM) exploitation and carbon dioxide sequestration. Because of the particularity of gas physical properties, it is difficult to visualize the gas diffusion-sorption process in coal by experimental methods. Due to the limitation of experimental approaches to image the three-dimensional coal pore structure, it is impossible to obtain the three-dimensional pore structure images of coal. As a result, the visualization of gas diffusion-sorption in coal pore structure by numerical ways is impossible. In this study, gas diffusion coefficients were firstly estimated by experiments. Then, a gas diffusion-sorption coupled model was developed which can be applied to the nanoscale geometry imaged by synchrotron radiation nano-CT. The dynamic process of gas diffusion and ad-/desorption in the nanoscale microstructure of coal was visualized by the developed gas diffusion-adsorption coupled model and the numerical simulation based on MATLAB. The simulation results show a good agreement with the experimental results. The gas diffusion-sorption coupled model and numerical method can help to investigate the effect of microstructure on gas diffusion and ad-/desorption and provides a possibility to investigate the multiscale gas transportation and adsorption in coal pore-fracture system.

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Kauffmann-Guerrero, Diego, Julian Taugner, Chukwuka Eze, Lukas Käsmann, Minglun Li, Amanda Tufman und Farkhad Manapov. „Clinical Management and Outcome of Grade III Pneumonitis after Chemoradioimmunotherapy for Inoperable Stage III Non-Small Cell Lung Cancer—A Prospective Longitudinal Assessment“. Diagnostics 11, Nr. 11 (23.10.2021): 1968. http://dx.doi.org/10.3390/diagnostics11111968.

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Background: Maintenance treatment with immune-checkpoint inhibition (ICI) has been shown to significantly improve patient prognosis after chemoradiotherapy (CRT) for inoperable stage III NSCLC. This survival advantage may be achieved at the expense of an increased probability for symptomatic pneumonitis as CRT as well as ICI treatment is associated with the risk of treatment-related pulmonary toxicity. Methods: We screened a prospective chemoradioimmunotherapy (CRT-IO) cohort consisting of 38 patients and identified patients with therapy-related grade 3 pneumonitis. All patients were treated with intravenous high dose corticosteroids and closely monitored by CT-scans and extended longitudinal lung function tests. We analyzed lung function parameters and CT morphological features to characterize patients’ outcome. Results: Six (16%) patients treated with CRT-IO developed grade 3 pneumonitis one to six months after completion CRT. In the CT imaging, pneumonitis was characterized by diffuse ground glass capacities and in part pulmonary consolidations within and outside the planning target volume. Onset of pneumonitis was accompanied by a reduction in diffusion capacity in all cases. The mean decline of diffusion capacity was 25.8% [6–53%]. Under treatment with corticosteroids, all patients recovered regarding symptoms and changes in CT morphology. In five out of six patients, diffusion capacity improved to at least 80% of the baseline [80–96%]. One patient showed a significant increase of diffusion capacity after treatment (from 32% to 53%) but reached only 62% of the initial value. Conclusions: Pneumonitis is a severe complication of CRT-IO. High-resolution CT imaging and extended lung function testing proved to be a suitable approach in detecting and monitoring of CRT-IO associated pneumonitis.

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Lee, So-Yeon, Won-Hee Jee, Ie Ryung Yoo, Joon-Yong Jung, Soo-A. Im, Yang-Guk Chung und Jin Hyoung Kang. „Comparison of 3T diffusion-weighted MRI and 18F-FDG PET/CT in musculoskeletal tumours: quantitative analysis of apparent diffusion coefficients and standardized uptake values“. British Journal of Radiology 92, Nr. 1102 (Oktober 2019): 20181051. http://dx.doi.org/10.1259/bjr.20181051.

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Objective: To determine whether the apparent diffusion coefficient (ADC) on 3T MR imaging including diffusion-weighted MR imaging (DWI) correlate with the standardized uptake value (SUV) on 18F-FDG PET/CT in musculoskeletal tumours. Methods: This retrospective cohort study included 57 patients (36 males, 21 females, mean age 54 years, range 12–90 years) with pathologically confirmed soft tissue (n = 32) and bone (n = 25) tumours who underwent 3T MR imaging including DWI and whole-body 18F-FDG PET/CT before treatment. 14 patients had follow-up MR imaging and 18F-FDG PET/CT after treatment. The minimum (ADCmin) and mean (ADCmean) ADCs of musculoskeletal tumour, ADC of normal skeletal muscle (ADCmus), SUVmax and SUVmean of musculoskeletal tumour were obtained. Correlation between ADCs and SUVs was assessed using Pearson correlation coefficients (r). ADCmin and SUVmax were compared between pretreatment and posttreatment by t-test. Results: There was inverse correlation between SUVmax and the ratio ADCmin/ADCmus (r = - 0.505 to - 0.495, p ≤ 0.001) and between SUVmean and the ratio ADCmean/ADCmus (r = - 0.501 to - 0.493, p = 0.001). After treatment ADC was significantly increased whereas SUV was significantly decreased (p = 0.001). There was significant correlation in percent change between the initial and follow-up values of ADCmin and SUVmax (r = 0.750 to 0.773, p ≤ 0.005). The ADCmin was increased by 163% and SUVmax was decreased by 61% in 11 patients with treatment response. Conclusion: ADC at 3T MR DWI and SUV at 18F-FDG PET/CT have an inverse correlation in musculoskeletal tumours. Advances in knowledge: Our study showed that ADC at 3T DWI and SUV at 18F-FDG PET/CT had an inverse correlation in musculoskeletal tumours.

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Digvijay Singh und Chanchal Kaushik. „Comparative Analysis of CT and MRI in Emergency Assessment of Stroke: A Review“. Journal of Multidisciplinary Research in Healthcare 5, Nr. 2 (08.04.2019): 57–63. http://dx.doi.org/10.15415/jmrh.2019.52007.

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Objective: To compare the diagnostic accuracy of computed tomography (CT) and magnetic resonance imaging (MRI)in emergency assessment of stroke in brain imaging from the review of literature. Method: Relevant databases (PubMed, google scholar etc.) were searched and literature were reviewed from 1995 to 2019. Literature from non-Scopus and unauthorized authorizations was excluded.Result: It was observed that for MRI DWI (Diffusion-weighted imaging) is preferred and in CT, axial sections are opted. In earlier studies, it was seen that neither CT nor MRI came out to besuperior. This may be due to the previous technology used. Some studies also, suggested that Diffusion-weighted imaging is highly accurate in diagnosis of stroke and also superior to CT. Another study suggested that SWI is a new approach in visualizing the hemorrhage in acute stroke. On one hand, evidence revealed that MRI is as good as CT. While on the other hand, literature concluded that CT angiography is good for intracranial and extracranial vasculature. Some studies suggested that CT is more reliable and is readily available for stroke. Conclusion: Present study concludes that both diagnostic imaging modalities i.e., CT and MRI have their advantages in diagnosis of ischemic and hemorrhagic stroke. Also chances of stroke increases with increase in age. Other factors influencing the stroke diagnosis and treatment are type of stroke, diagnostic imaging modality available, and cost-effectiveness of diagnostic exams performed.

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Wu, Hung-Ming, I.-Hui Lee, Chao-Bao Luo, Chih-Ping Chung und Yung-Yang Lin. „Clinical-CT mismatch defined NIHSS ≥ 8 and CT-ASPECTS ≥ 9 as a reliable marker of candidacy for intravenous thrombolytic therapy in acute ischemic stroke“. PLOS ONE 16, Nr. 4 (30.04.2021): e0251077. http://dx.doi.org/10.1371/journal.pone.0251077.

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Background Clinical-diffusion mismatch between stroke severity and diffusion-weighted imaging lesion volume seems to identify stroke patients with penumbra. However, urgent magnetic resonance imaging is sometimes inaccessible or contraindicated. Thus, we hypothesized that using brain computed tomography (CT) to determine a baseline “clinical-CT mismatch” may also predict the responses to thrombolytic therapy. Methods Brain CT lesions were measured using the Alberta Stroke Program Early CT Score (ASPECTS). A total of 104 patients were included: 79 patients with a baseline National Institutes of Health Stroke Scale (NIHSS) score ≥ 8 and a CT-ASPECTS ≥ 9 who were defined as clinical-CT mismatch-positive (P group) and 25 patients with an NIHSS score ≥ 8 and a CT-ASPECTS < 9 who were defined as clinical-CT mismatch-negative (the N group). We compared their clinical outcomes, including early neurological improvement (ENI), early neurological deterioration (END), delta NIHSS score (admission NIHSS—baseline NIHSS score), symptomatic intracranial hemorrhage (sICH), mortality, and favorable outcome at 3 months. Results Patients in the P group had a greater proportion of favorable outcome at 3 months (p = 0.032) and more frequent ENI (p = 0.038) and a greater delta NIHSS score (p = 0.001), as well as a lower proportion of END (p = 0.004) than those in the N group patients. There were no significant differences in the incidence rates of sICH and mortality between the two groups. Conclusions Clinical-CT mismatch may be able to predict which patients would benefit from intravenous thrombolysis.

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Hafeez, Moiz, und Nazir Khan. „DWI and NCCT - Ischemic patterns in global anoxic brain injury“. IP Indian Journal of Neurosciences 7, Nr. 3 (15.09.2021): 251–53. http://dx.doi.org/10.18231/j.ijn.2021.045.

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This case report highlights differences between diffusion weighted imaging (DWI) and computed tomography (CT) with respect to the extent of ischemic changes detectable in brain parenchyma during global anoxic brain injury. Brain CT in a 65 year old patient post cardiac arrest showed striking diffuse loss of Gray-White matter differentiation consistent with global anoxic brain injury while magnetic resonance imaging (MRI) performed 3 days later showed diffusion restriction and hyperintensity only in select areas. DWI hyperintensity was seen in diverse structures including the hippocampi, globus pallidus, forniceal columns, medial occipital lobes as well as the left amygdala. Although generally presumed to be the most sensitive modality for detecting parenchymal ischemia, this case demonstrates that CT may sometimes better capture the extent of parenchymal damage during anoxic brain injury.

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Zhang, Jing, Xu Bai, Jing Yuan, Xiaojing Zhang, Wei Xu, Huiyi Ye und Haiyi Wang. „Bladder paraganglioma: CT and MR imaging characteristics in 16 patients“. Radiology and Oncology 56, Nr. 1 (30.12.2021): 46–53. http://dx.doi.org/10.2478/raon-2021-0055.

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Abstract Background Bladder paraganglioma (BPG) is a rare extra-adrenal pheochromocytoma with variable symptoms and easy to be misdiagnosed and mishandled. The aim of the study was to document the imaging features of BPG using computed tomography (CT) and magnetic resonance imaging (MRI). Patients and methods We retrospectively enrolled consecutive patients with pathology-proven BPG, who underwent CT or MRI examinations before surgery between October 2009 and October 2017. The clinical characteristics, CT, and MRI features of the patients were described and analysed. Results A total of 16 patients with 16 bladder tumours (median age 51 years, 9 females) were included. Among them, 13 patients underwent CT examinations and eight patients underwent MRI examinations preoperatively. Tumour diameters ranged from 1.6−5.4 cm. Most of the tumours grew into the bladder cavity (n = 11) with oval shapes (n = 10) and well-defined margins (n = 14). Intratumour cystic degeneration or necrosis (n = 2) was observed. Two lesions showed peripheral tissue invasion, suggesting malignant BPGs. All 13 lesions imaged with CT exhibited slight hypoattenuation and moderate to marked enhancement. Compared to the gluteus maximus, all lesions showed slight h yperintensity in T2-weighted images, hyperintensity on diffusion-weighted images (DWI), hypointensity on apparent diffusion coefficient maps, hyperintensity on T1-weighted images and a “fast in and slow out” enhanced pattern on contrast-enhanced MRI images. Conclusions BPGs are mostly oval-shaped, broadly-based and hypervascular bladder tumours with hypoattenuation on non-contrast CT, T2 hyperintensity, slight T1 hyperintensity compared to the muscle, marked restricted diffusion on DWI. Peripheral tissue invasion can suggest malignancy of the BPGs. All of these features contribute to preoperative decision-making.

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Wen, Han, Julio A. Huapaya, Shreya M. Kanth, Junfeng Sun, Brianna P. Matthew, Simone C. Lee, Michael Do, Marcus Y. Chen, Ashkan A. Malayeri und Anthony F. Suffredini. „Quantitative CT Metrics Associated with Variability in the Diffusion Capacity of the Lung of Post-COVID-19 Patients with Minimal Residual Lung Lesions“. Journal of Imaging 9, Nr. 8 (26.07.2023): 150. http://dx.doi.org/10.3390/jimaging9080150.

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(1) Background: A reduction in the diffusion capacity of the lung for carbon monoxide is a prevalent longer-term consequence of COVID-19 infection. In patients who have zero or minimal residual radiological abnormalities in the lungs, it has been debated whether the cause was mainly due to a reduced alveolar volume or involved diffuse interstitial or vascular abnormalities. (2) Methods: We performed a cross-sectional study of 45 patients with either zero or minimal residual lesions in the lungs (total volume < 7 cc) at two months to one year post COVID-19 infection. There was considerable variability in the diffusion capacity of the lung for carbon monoxide, with 27% of the patients at less than 80% of the predicted reference. We investigated a set of independent variables that may affect the diffusion capacity of the lung, including demographic, pulmonary physiology and CT (computed tomography)-derived variables of vascular volume, parenchymal density and residual lesion volume. (3) Results: The leading three variables that contributed to the variability in the diffusion capacity of the lung for carbon monoxide were the alveolar volume, determined via pulmonary function tests, the blood vessel volume fraction, determined via CT, and the parenchymal radiodensity, also determined via CT. These factors explained 49% of the variance of the diffusion capacity, with p values of 0.031, 0.005 and 0.018, respectively, after adjusting for confounders. A multiple-regression model combining these three variables fit the measured values of the diffusion capacity, with R = 0.70 and p < 0.001. (4) Conclusions: The results are consistent with the notion that in some post-COVID-19 patients, after their pulmonary lesions resolve, diffuse changes in the vascular and parenchymal structures, in addition to a low alveolar volume, could be contributors to a lingering low diffusion capacity.

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Wu, Qian, Lingshan Zhong, Hongwei Li, Jing Guo, Yajie Li, Xinwei Hou, Fangfei Yang, Yi Xie, Li Li und Zhiheng Xing. „A Follow-Up Study of Lung Function and Chest Computed Tomography at 6 Months after Discharge in Patients with Coronavirus Disease 2019“. Canadian Respiratory Journal 2021 (13.02.2021): 1–7. http://dx.doi.org/10.1155/2021/6692409.

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We aimed to investigate changes in pulmonary function and computed tomography (CT) findings in patients with coronavirus disease 2019 (COVID-19) during the recovery period. COVID-19 patients underwent symptom assessment, pulmonary function tests, and high-resolution chest CT 6 months after discharge from the hospital. Of the 54 patients enrolled, 31 and 23 were in the moderate and severe group, respectively. The main symptoms 6 months after discharge were fatigue and exertional dyspnea, experienced by 24.1% and 18.5% of patients, respectively, followed by smell and taste dysfunction (9.3%) and cough (5.6%). One patient dropped out of the pulmonary function tests. Of the remaining 54 patients, 41.5% had pulmonary dysfunction. Specifically, 7.5% presented with restrictive ventilatory dysfunction (forced vital capacity <80% of the predicted value), 18.9% presented with small airway dysfunction, and 32.1% presented with pulmonary diffusion impairment (diffusing capacity for carbon monoxide <80% of the predicted value). Of the 54 patients enrolled, six patients dropped out of the chest CT tests. Eleven of the remaining 48 patients presented with abnormal lung CT findings 6 months after discharge. Patients with residual lung lesions were more common in the severe group (52.6%) than in the moderate group (3.4%); a higher proportion of patients had involvement of both lungs (42.1% vs. 3.4%) in the severe group. The residual lung lesions were mainly ground-glass opacities (20.8%) and linear opacities (14.6%). Semiquantitative visual scoring of the CT findings revealed significantly higher scores in the left, right, and both lungs in the severe group than in the moderate group. COVID-19 patients 6 months after discharge mostly presented with fatigue and exertional dyspnea, and their pulmonary dysfunction was mostly characterized by pulmonary diffusion impairment. As revealed by chest CT, the severe group had a higher prevalence of residual lesions than the moderate group, and the residual lesions mostly manifested as ground-glass opacities and linear opacities.

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Tu, Zhanhai, Zebin Xiao, Yingyan Zheng, Hongjie Huang, Libin Yang und Dairong Cao. „Benign and malignant skull-involved lesions: discriminative value of conventional CT and MRI combined with diffusion-weighted MRI“. Acta Radiologica 60, Nr. 7 (09.05.2018): 880–86. http://dx.doi.org/10.1177/0284185118773541.

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Background Little is known about the value of computed tomography (CT) and magnetic resonance imaging (MRI) combined with diffusion-weighted imaging (DWI) in distinguishing malignant from benign skull-involved lesions. Purpose To evaluate the discriminative value of DWI combined with conventional CT and MRI for differentiating between benign and malignant skull-involved lesions. Material and Methods CT and MRI findings of 58 patients with pathologically proven skull-involved lesions (43 benign and 15 malignant) were retrospectively reviewed. Conventional CT and MRI characteristics and apparent diffusion coefficient (ADC) value of the two groups were evaluated and compared. Multivariate logistic regression and receiver operating characteristic (ROC) curve analyses were performed to assess the differential performance of each parameter separately and together. Results The presence of cortical defects or break-through and ill-defined margins were associated with malignant skull-involved lesions (both P < 0.05). Malignant skull-involved lesions demonstrated a significantly lower ADC ( P = 0.016) than benign lesions. ROC curve analyses indicated that a combination of CT, MRI, and DWI with an ADC ≤ 0.703 × 10–3 mm2/s showed optimal sensitivity, while DWI along showed optimal specificity of 88.4% in differentiating between benign and malignant skull-involved lesions. Conclusion The combination of CT, MRI, and DWI can help to differentiate malignant from benign skull-involved lesions. CT + MRI + DWI offers optimal sensitivity, while DWI offers optimal specificity.

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Murase, Kenya, Takafumi Nanjo, Yoshifumi Sugawara, Masaaki Hirata und Teruhito Mochizuki. „Usefulness of an Anisotropic Diffusion Method in Cerebral CT Perfusion Study Using Multi-Detector Row CT“. Open Journal of Medical Imaging 05, Nr. 03 (2015): 106–16. http://dx.doi.org/10.4236/ojmi.2015.53015.

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Lansberg, M. G., G. W. Albers, C. Beaulieu und M. P. Marks. „Comparison of diffusion-weighted MRI and CT in acute stroke“. Neurology 54, Nr. 8 (25.04.2000): 1557–61. http://dx.doi.org/10.1212/wnl.54.8.1557.

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von Kummer, R., G. Gahn, M. P. Marks, G. Albers und M. Lansberg. „Comparison of diffusion-weighted MRI and CT in acute stroke“. Neurology 55, Nr. 11 (12.12.2000): 1760. http://dx.doi.org/10.1212/wnl.55.11.1760.

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Konukoğlu, E., und B. Acar. „HDF: Heat diffusion fields for polyp detection in CT colonography“. Signal Processing 87, Nr. 10 (Oktober 2007): 2407–16. http://dx.doi.org/10.1016/j.sigpro.2007.03.021.

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Neuschuler, R., C. Simonetti, V. Gasparri, E. Cantera, E. Ferone, R. Floris, A. Orlacchio und C. Guinetti. „Pattern of Anesthetic Diffusion during Peribulbar Infiltration: A Ct Evaluation“. European Journal of Ophthalmology 6, Nr. 3 (Juli 1996): 336–39. http://dx.doi.org/10.1177/112067219600600320.

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Junghähnel, Gerhard, Roland Gall und Gerold Proksch. „Charge-transfer-Komplexe; Diffusion und CT-Komplexbildung in dünnen Schichten“. Zeitschrift für Chemie 15, Nr. 3 (01.09.2010): 115–17. http://dx.doi.org/10.1002/zfch.19750150320.

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Alle, María Fernanda. „Cuadernos de Cultura y la conformación de un ámbito de poéticas comunistas en la Argentina de los años 50“. Catedral Tomada. Revista de crítica literaria latinoamericana 7, Nr. 12 (26.07.2019): 218–51. http://dx.doi.org/10.5195/ct/2019.373.

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This paper inquire the configuration of an area of communist poetics in the framework of the magazine Cuadernos de Cultura in the 1950s. It is argued that the literary program defined from Cuadernos gave a prominent place to the diffusion and promotion of the poetic genre, from the assiduous publication of reviews, notes, critical commentaries and poems, that influenced the conformation of a specific field of “communist poetics”, identified, according to the Soviet programs that the magazine adopts, for its realism and national character. This field gets together a broad group of poets who come from the metropolitan center and the interior of the country. In this direction, the politic “poetic” that the magazine put into play resulted in a reconfiguration of the central and peripheral spaces of the communist left’s sector of the poetic field.

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Ngoret, Joshua K., und Venkata P. Kommula. „Role of Aluminide coating degradation on Inconel 713 LC used for Compressor Turbines (CT) of Short-haul Aircrafts“. MRS Advances 3, Nr. 38 (2018): 2281–96. http://dx.doi.org/10.1557/adv.2018.207.

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ABSTRACTThis paper investigates the role degradation of protective diffusion aluminide coating on Inconel 713LC used for CT blades of short-haul aircraft fleet played in having the blades prematurely retired from service at 6378 hours, as opposed to their pre-set service time of 10000 hours. The blade samples were subjected to various examinations; X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analyse at the; tips, airfoil, as well as the base, transverse and longitudinal, sectioned and unsectioned. As affirmed by both the transverse and longitudinal sections examinations, it was established that thermal attack leading to deterioration of the coating was greater at the tip and airfoils of the blades (the hotter zones) and lesser towards the bases (colder zones). As a result, severe degradation of the core material at the tips and airfoils compared to the bases and more prevalent at the leading edges than trailing edges at the tips. The results further suggest that both active outward Ni diffusion and inward Al diffusion can coexist during exploitation of the blades in service. The study illustrates the role played by the aluminide coating in early failure of CT blades with the aim of bettering the surface coatings and enhancing coating technologies, managing CT blade material monitoring as well as to give insights on advancing CT blades maintenance practices.

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Nesterova, E. S., G. A. Yatsyk, N. S. Lutsik, S. K. Kravchenko, A. B. Sudarikov, I. V. Krasil‘nikova, E. G. Gemdzhian und A. M. Kovrigina. „Informativeness of whole-body diffusion-weighted magnetic resonance imaging and positron emission tomography with computed tomography in follicular lymphoma“. Terapevticheskii arkhiv 92, Nr. 7 (01.09.2020): 55–62. http://dx.doi.org/10.26442/00403660.2020.07.000774.

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Aim.This study conducted the possibilities of diffusion-weighted magnetic resonance imaging of the whole body diffusion WB-MRI (in comparison with positron emission tomography with computed tomography PET/CT) in assessing the volume and prevalence of the tumor, as well as determining bone marrow (BM) damage (for various cytological types) in the diagnosis and staging of the disease in patients with FL. Materials and methods.A prospective comparative search study included 15 patients (4 men and 11 women, with a median age of 53 years) with newly diagnosed FL. Patients have not received antitumor chemotherapy previously. After the diagnosis was established, all patients (with the blindness of both the cases themselves and some specialists regarding the results of other specialists) were examined by PET/CT and diffusion WB-MRI, after which a BM examination was performed (histological examination and determination of B-cell clonality in BM puncture by PCR). Using the diffusion WB-MRI method, the prevalence of tumor lesion (nodal and extranodal foci) in each patient was estimated, and the total tumor volume was calculated, BM lesion was detected, and BM lesion volume was calculated. For lesions of different localization, the measured diffusion coefficient (DC) of the diffusion WB-MRI and the standardized rate of accumulation of the radiopharmaceutical in tissues (SUV) of the PET/CT method were determined and compared with each other (for the same areas). Statistical analysis was performed using the estimate of agreement (by Cohens kappa coefficient and asymptotic test) of the results of the compared methods. Results.Estimates of the prevalence of tumor damage (lymph nodes and extranodal foci) using the diffusion WB-MRI and PET/CT methods were the same. High DC and SUV were observed in the peripheral lymph nodes, extranodal foci and bulky, low DC and SUV in the foci of BM. All 4 methods successfully determined BM damage, however, the diffusion WB-MRI had comparatively less negative results. The highest values of SUV and CD were noted in cases of the 3 grade of FL. Using the diffusion WB-MRI method, the prevalence of tumor lesion was assessed in each patient (nodal and extranodal foci were detected) and the total tumor volume was calculated, BM lesion detection was performed, and the volume of BM lesion was calculated. It is important to note that with the help of diffusion WB-MRI, it was possible to measure separately the total tumor volume (462025 cm3) and separately the volume of bulky (251358 cm3). The diffusion WB-MRI allowed us to differentiate the volume of tumor tissue (reduced as a result of treatment) and residual (fibrous-adipose) tissue in residual formations (which averaged 21% of the initial volume). The predictors of a poor antitumor response were the maximum SUV values (more than 14.0) and the minimum DC values (0.510-3mm2/s) in the BM foci. Conclusion.The diffusion WB-MRI allows for detailed visualization of BM lesions and surrounding soft tissues both in the debut of the FL and in the process of tracking the effectiveness of chemotherapy, which makes it possible to use it along with PET/CT. Diffusion WB-MRI allows to separately evaluate the volume of true tumor tissue and residual tissue. Cases of the 3 grade of FL (including the transformation of FL into diffuse B-large cell lymphoma) are isolated due to low DC values (and high SUV values) in the tumor tissue. BM foci of FL lesion also have (in comparison with nodal and extranodal foci) lower DC values. The predictors of a poor antitumor response were high (from 14.0 or more) SUV valuesin the tumor (and especially in bulky), and low (about 0.5103mm2/s) DC values of BM foci. The PET/CT and diffusion WB-MRI have proven to be reliable diagnostic tools for establishing the stage of FL and detecting BM damage. Diffusion WB-MRI for FL is an informative first-line diagnostic method that allows regular monitoring of the disease and early detection of foci of relapse and disease progression.

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Wu, Pei-Yu, Sheng-Fung Lin, Ping-Hsun Wu, Yi-Chun Tsai, Yu-Ting Kuo, Mei-Chuan Kuo und Hung-Chun Chen. „Multiple Hypovascular Tumors in Kidney: A Rare Case Report and Differential Diagnosis“. Case Reports in Medicine 2013 (2013): 1–4. http://dx.doi.org/10.1155/2013/595193.

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The most common malignant renal tumor is renal cell carcinoma and surgery is the standard treatment. The proportion of lymphoma with renal involvement is 2~15% and lymphoma could be cured by chemotherapy without nephrectomy. Sonography, computed tomography (CT), and magnetic resonance imaging (MRI) can detect and characterize a renal mass. We present a case of right renal hypovascular tumors and differential diagnosis of hypovascular tumors by image study. CT scan showed hypovascular tumors and MRI image revealed multifocal hypovascular solid tumors with significantly increased apparent diffusion coefficient (ADC) of diffusion weighted imaging (DWI). Based on image finding, renal lymphoma was highly suspected. Renal lymphoma was confirmed by renal biopsy and this patient received chemotherapy without surgery. The noninvasive CT scan and MRI image can help clinicians to diagnose the characteristics of renal mass and to avoid unnecessary nephrectomy.

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Shapira-Zaltsberg, Gali, Nagwa Wilson, Esther Trejo Perez, Lesleigh Abbott, Stephen Dinning, Cassandra Kapoor, Jorge Davila, Barry Smith und Elka Miller. „Whole-Body Diffusion-Weighted MRI Compared to 18 FFDG PET/CT in Initial Staging and Therapy Response Assessment of Hodgkin Lymphoma in Pediatric Patients“. Canadian Association of Radiologists Journal 71, Nr. 2 (22.01.2020): 217–25. http://dx.doi.org/10.1177/0846537119888380.

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Purpose: The aim of our study was to compare whole-body diffusion-weighted MRI (WB-DWI-MRI) to fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) in the assessment of initial staging and treatment response in pediatric patients with Hodgkin lymphoma. Materials and Methods: This prospective study comprised 11 children with Hodgkin lymphoma. Whole-body DWI-MRI and FDG-PET/CT were obtained at baseline and after 2 cycles of chemotherapy. Two radiologists measured the apparent diffusion coefficient (ADC) values of the sites of involvement agreed upon in consensus and 1 nuclear medicine physician assessed the PET/CT. Reliability of radiologists’ ratings was assessed by intraclass correlation coefficients (ICC2,1). The sensitivity and positive predictive value (PPV) of DW-MRI relative to PET/CT were calculated for nodal and extranodal sites. The patients were staged according to both modalities. Association of treatment responses was assessed through the Pearson correlation between the ADC ratios and the change standardized uptake value (SUV) between baseline and follow-up. Results: There was good agreement between the raters for nodal and extranodal ADC measurements. The sensitivity and PPV of DW-MRI relative to PET/CT of nodal disease was 0.651 and 1.0, respectively, at baseline, and 0.697 and 0.885 at follow-up. The sensitivity and PPV of extranodal disease were 0.545 and 0.6 at baseline, and 0.167 and 0.333 at follow-up. Diffusion-weighted MRI determined correct tumor stage in 8 of 11 examinations. There was poor correlation between the ADC ratios and the absolute change in SUV between baseline and follow-up (0.348). Conclusion: Our experience showed that WB-DWI-MRI is inferior to PET/CT for initial staging and assessment of treatment response of Hodgkin lymphoma in pediatric patients.

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Zhang, Yi, Yi-Fei Pu, Jin-Rong Hu, Yan Liu, Qing-Li Chen und Ji-Liu Zhou. „Efficient CT Metal Artifact Reduction Based on Fractional-Order Curvature Diffusion“. Computational and Mathematical Methods in Medicine 2011 (2011): 1–9. http://dx.doi.org/10.1155/2011/173748.

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We propose a novel metal artifact reduction method based on a fractional-order curvature driven diffusion model for X-ray computed tomography. Our method treats projection data with metal regions as a damaged image and uses the fractional-order curvature-driven diffusion model to recover the lost information caused by the metal region. The numerical scheme for our method is also analyzed. We use the peak signal-to-noise ratio as a reference measure. The simulation results demonstrate that our method achieves better performance than existing projection interpolation methods, including linear interpolation and total variation.

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Camargo, Selma Cristina Cury, Giulio Gavini, Carlos Eduardo Aun, Douglas Waterfield und Jeffrey M. Coil. „Diffusion of calcitonin through the wall of the root canal“. Brazilian Oral Research 18, Nr. 1 (März 2004): 59–62. http://dx.doi.org/10.1590/s1806-83242004000100011.

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The aim of this study was to evaluate the in vitro diffusion of synthetic salmon calcitonin (CT), used as an intracanal medication, to the external root surface, with or without the presence of intact root cementum. Fifty-four human central incisors were used in the experiment, and were divided into two groups of 21 (test groups) and two groups of 6 teeth (control groups). After root canal preparation, 10 ml of calcitonin was inserted within the root canal chamber. The root was sealed and made externally impermeable. Specimens were then placed in tubes with saline solution buffered with phosphates and stored at 37°C. The diffusion of calcitonin was measured after 1, 4 and 7 days. To count calcitonin present at the external media (PBS), ELISA test (an antigen-antibody reaction) was used. Results showed that there was calcitonin diffusion through dentin in all of the test samples. The absence of cementum increased the diffusion of calcitonin (p=0.05). The highest counts of CT were obtained on day 7 for groups with or without cementum - showing a direct relation between time and diffusion of the medication.

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Wong, Y. Y., und W. W. M. Lam. „Diffusion-weighted imaging in hyperacute stroke – gold standard?“ Acta Radiologica 44, Nr. 5 (September 2003): 547–49. http://dx.doi.org/10.1080/j.1600-0455.2003.00112.x.

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Diffusion-weighted imaging (DWI) is more sensitive than CT and conventional T2-weighted MR imaging in the detection of early cerebral ischemia and infarction. In this case report, we present a case of a 79-year-old woman with symptoms of acute stroke, clinically and radiologically documented progression to complete stroke with an initial negative diffusion-weighted scan.

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Al-Hemiri, Adel. „A PARTICULAR SOLUTION OF THE TWO AND THREE DIMENSIONAL TRANSIENT DIFFUSION EQUATIONS“. Iraqi Journal of Chemical and Petroleum Engineering 12, Nr. 2 (30.06.2011): 18–20. http://dx.doi.org/10.31699/ijcpe.2011.2.3.

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A particular solution of the two and three dimensional unsteady state thermal or mass diffusion equation is obtained by introducing a combination of variables of the form,η = (x+y) / √ct , and η = (x+y+z) / √ct, for two and three dimensional equationsrespectively. And the corresponding solutions are,θ (t,x,y) = θ0 erfc (x+y)/√8ct and θ( t,x,y,z) =θ0 erfc (x+y+z/√12ct)

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VORST, KEITH L., EWEN C. D. TODD und ELLIOT T. RYSER. „Improved Quantitative Recovery of Listeria monocytogenes from Stainless Steel Surfaces Using a One-Ply Composite Tissue“. Journal of Food Protection 67, Nr. 10 (01.10.2004): 2212–17. http://dx.doi.org/10.4315/0362-028x-67.10.2212.

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Four sampling devices, a sterile environmental sponge (ES), a sterile cotton-tipped swab (CS), a sterile calcium alginate fiber-tipped swab (CAS), and a one-ply composite tissue (CT), were evaluated for quantitative recovery of Listeria monocytogenes from a food-grade stainless steel surface. Sterile 304-grade stainless steel plates (6 by 6 cm) were inoculated with approximately 106 CFU/cm2 L. monocytogenes strain Scott A and dried for 1 h. The ES and CT sampling devices were rehydrated in phosphate buffer solution. After plate swabbing, ES and CT were placed in 40 ml of phosphate buffer solution, stomached for 1 min and hand massaged for 30 s. Each CS and CAS device was rehydrated in 0.1% peptone before swabbing. After swabbing, CS and CAS were vortexed in 0.1% peptone for 1 min. Samples were spiral plated on modified Oxford agar with modified Oxford agar Rodac Contact plates used to recover any remaining cells from the stainless steel surface. Potential inhibition from CT was examined in both phosphate buffer solution and in a modified disc-diffusion assay. Recovery was 2.70, 1.34, and 0.62 log greater using CT compared with ES, CS, and CAS, respectively, with these differences statistically significant (P < 0.001) for ES and CT and for CAS, CS, and CT (P < 0.05). Rodac plates were typically overgrown following ES, positive after CS and CAS, and negative after CT sampling. CT was noninhibitory in both phosphate buffer solution and the modified disc-diffusion assay. Using scanning electron microscopy, Listeria cells were observed on stainless steel plates sampled with each sampling device except CT. The CT device, which is inexpensive and easy to use, represents a major improvement over other methods in quantifying L. monocytogenes on stainless steel surfaces and is likely applicable to enrichment of environmental samples.

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