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Journal articles on the topic 'Catphan'

Author: Grafiati
Published: 4 June 2021
Last updated: 3 February 2022

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1

Nelson, G. "WE-D-204-06: An Open Source ImageJ CatPhan Analysis Tool." Medical Physics 42, no. 6Part38 (June 2015): 3671. http://dx.doi.org/10.1118/1.4925946.

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2

Santos, J., M. d. C. Batista, S. Foley, G. Paulo, M. F. McEntee, and L. Rainford. "Paediatric CT optimisation utilising Catphan(R) 600 and age-specific anthropomorphic phantoms." Radiation Protection Dosimetry 162, no. 4 (February 23, 2014): 586–96. http://dx.doi.org/10.1093/rpd/ncu018.

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3

Biondi, M., A. Bogi, L. N. Mazzoni, E. Vanzi, G. M. Belmonte, G. De Otto, R. Martini, et al. "A novel ImageJ macro for Catphan low contrast module analysis: Preliminary results." Physica Medica 32 (February 2016): 72. http://dx.doi.org/10.1016/j.ejmp.2016.01.247.

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4

Husby, Ellen, Elisabeth D. Svendsen, Hilde K. Andersen, and Anne Catrine T. Martinsen. "100 days with scans of the same Catphan phantom on the same CT scanner." Journal of Applied Clinical Medical Physics 18, no. 6 (September 18, 2017): 224–31. http://dx.doi.org/10.1002/acm2.12186.

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5

Geso, Moshi, Salem Saeed Alghamdi, Abdulrahman Tajaldeen, Rowa Aljondi, Hind Alghamdi, Ali Zailae, Essam H. Mattar, et al. "Modified Contrast-Detail Phantom for Determination of the CT Scanners Abilities for Low-Contrast Detection." Applied Sciences 11, no. 14 (July 20, 2021): 6661. http://dx.doi.org/10.3390/app11146661.

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Computerised tomography (CT) continues to be a corner stone medical and radiologic imaging modalities in radiology and radiotherapy departments. Its importance lies in its efficiency in low contrast detectability (LCD). The assessment of such capabilities requires rigorous image quality analysis using special designed phantoms with different densities as well as variation in atomic mass numbers (A) of the material. Absence of such ranges of densities and atomic mass numbers, limits the dynamic range of assessment. An example is Catphan phantom which represents only three subject contrast levels 0.3, 0.5 and 1 per cent. This project aims to present a phantom with extended range of available subject contrast to include very low-level values and to increase its dynamic scale. With this design, a relatively large number of different contrast objects (holes) can be presented for imaging by a CT scanner to assess its LCD ability. We shall thus introduce another LCD phantom to complement the existing ones, such as Catphan. The cylindrical phantom is constructed using Poly (methyl methacrylate) (PMMA), with craters (holes) having dimensions that gradually increase from 1.0 to 12.5 mm penetrated in configuration that extend from the centre to the corner. Each line of the drilled holes in the phantom is filled with contrast material of specific concentrations. As opposed to the phantom of low detail contrast used in planar imaging, the iodine (contrast material) in this phantom replaces the depth of the phantom holes. The iodine could be reduced to 0.2 l milli-Molar (mM) and can be varied for the next line of holes by a small increment depending on the required level of contrast detectability assessment required.
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6

Irvine, Denise, and Mark McJury. "Aspects of simulator cone-beam CT for radiotherapy treatment planning." Journal of Radiotherapy in Practice 9, no. 3 (September 2010): 165–74. http://dx.doi.org/10.1017/s1460396910000026.

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AbstractBackground and purpose: Following a recent major upgrade in cone-beam computed tomography (CBCT) software and functionality, we have reassessed aspects of our Varian Acuity simulator performance for use in treatment planning. The feasibility of using CBCT for treatment planning has been assessed and here we report specifically on Hounsfield number (HN) accuracy and related dose errors, and digitally reconstructed radiograph (DRR) image quality.Methods: Using a Catphan® 600 CT phantom, HN accuracy and uniformity were investigated for a range of CBCT imaging modes. This included the variation in HNs with scan length and phantom position. Results were compared with those acquired from conventional CT. Treatment plans for three sites were generated using the Rando phantom, and results from CBCT-based data were compared to that from CT-based data using a gamma analysis. Image quality of DRRs based on CBCT data were compared with those from CT data both quantitatively, by calculating the modulation transfer function (MTF) and qualitatively, by counting the number of line pairs visible on a phantom.Results and conclusions: Catphan data showed that for certain cases, the HN calibration of the Acuity CBCT was out of tolerance and could lead to errors in dose calculation of >2%. HNs were only acceptable for scan lengths >10 cm. In multi-scan mode, geometric shifts and differences in HNs were seen on CT slices on either side of the interface between the two acquisitions. However, comparisons between treatment plans calculated using CBCT data and conventional CT data from Rando phantoms showed that head, pelvis and thorax plans were acceptable. CBCT DRR image quality compared favourably with a conventional CT scanner in some respects; however, image uniformity and low contrast resolution were poorer due to the ‘cupping’ artefact obtained with CBCT scans.
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Volz, Lennart, Charles-Antoine Collins-Fekete, Pierluigi Piersimoni, Robert P. Johnson, Vladimir Bashkirov, Reinhard Schulte, and Joao Seco. "Stopping power accuracy and achievable spatial resolution of helium ion imaging using a prototype particle CT detector system." Current Directions in Biomedical Engineering 3, no. 2 (September 7, 2017): 401–4. http://dx.doi.org/10.1515/cdbme-2017-0084.

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AbstractA precise relative stopping power map of the patient is crucial for accurate particle therapy. Charged particle imaging determines the stopping power either tomographically – particle computed tomography (pCT) – or by combining prior knowledge from particle radiography (pRad) and x-ray CT. Generally, multiple Coulomb scattering limits the spatial resolution. Compared to protons, heavier particles scatter less due to their lower charge/mass ratio. A theoretical framework to predict the most likely trajectory of particles in matter was developed for light ions up to carbon and was found to be the most accurate for helium comparing for fixed initial velocity. To further investigate the potential of helium in particle imaging, helium computed tomography (HeCT) and radiography (HeRad) were studied at the Heidel-berg Ion-Beam Therapy Centre (HIT) using a prototype pCT detector system registering individual particles, originally developed by the U.S. pCT collaboration. Several phantoms were investigated: modules of the Catphan QA phantom for analysis of spatial resolution and achievable stopping power accuracy, a paediatric head phantom (CIRS) and a custom-made phantom comprised of animal meat enclosed in a 2 % agarose mixture representing human tissue. The pCT images were reconstructed applying the CARP iterative reconstruction algorithm. The MTF10% was investigated using a sharp edge gradient technique. HeRad provides a spatial resolution above that of protons (MTF1010%=6.07 lp/cm for HeRad versus MTF10%=3.35 lp/cm for proton radiography). For HeCT, the spatial resolution was limited by the number of projections acquired (90 projections for a full scan). The RSP accuracy for all inserts of the Catphan CTP404 module was found to be 2.5% or better and is subject to further optimisation. In conclusion, helium imaging appears to offer higher spatial resolution compared to proton imaging. In future studies, the advantage of helium imaging compared to other imaging modalities in clinical applications will be further explored.
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8

Zhang, Hong, Vic Kong, Ke Huang, and Jian-Yue Jin. "Correction of Bowtie-Filter Normalization and Crescent Artifacts for a Clinical CBCT System." Technology in Cancer Research & Treatment 16, no. 1 (June 23, 2016): 81–91. http://dx.doi.org/10.1177/1533034615627584.

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Purpose: To present our experiences in understanding and minimizing bowtie-filter crescent artifacts and bowtie-filter normalization artifacts in a clinical cone beam computed tomography system. Methods: Bowtie-filter position and profile variations during gantry rotation were studied. Two previously proposed strategies (A and B) were applied to the clinical cone beam computed tomography system to correct bowtie-filter crescent artifacts. Physical calibration and analytical approaches were used to minimize the norm phantom misalignment and to correct for bowtie-filter normalization artifacts. A combined procedure to reduce bowtie-filter crescent artifacts and bowtie-filter normalization artifacts was proposed and tested on a norm phantom, CatPhan, and a patient and evaluated using standard deviation of Hounsfield unit along a sampling line. Results: The bowtie-filter exhibited not only a translational shift but also an amplitude variation in its projection profile during gantry rotation. Strategy B was better than strategy A slightly in minimizing bowtie-filter crescent artifacts, possibly because it corrected the amplitude variation, suggesting that the amplitude variation plays a role in bowtie-filter crescent artifacts. The physical calibration largely reduced the misalignment-induced bowtie-filter normalization artifacts, and the analytical approach further reduced bowtie-filter normalization artifacts. The combined procedure minimized both bowtie-filter crescent artifacts and bowtie-filter normalization artifacts, with Hounsfield unit standard deviation being 63.2, 45.0, 35.0, and 18.8 Hounsfield unit for the best correction approaches of none, bowtie-filter crescent artifacts, bowtie-filter normalization artifacts, and bowtie-filter normalization artifacts + bowtie-filter crescent artifacts, respectively. The combined procedure also demonstrated reduction of bowtie-filter crescent artifacts and bowtie-filter normalization artifacts in a CatPhan and a patient. Conclusion: We have developed a step-by-step procedure that can be directly used in clinical cone beam computed tomography systems to minimize both bowtie-filter crescent artifacts and bowtie-filter normalization artifacts.
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9

Zarb, Francis, and Louise Rainford. "Psychophysical evaluation of Catphan®600 CT image quality findings using human observers and software analysis." Radiography 20, no. 4 (November 2014): 318–22. http://dx.doi.org/10.1016/j.radi.2014.03.014.

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10

Davis, Anne T., Antony L. Palmer, and Andrew Nisbet. "Can different Catphan phantoms be used in a multi-centre audit of radiotherapy CT image quality?" Physica Medica 78 (October 2020): 38–47. http://dx.doi.org/10.1016/j.ejmp.2020.09.003.

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11

Bonatto, Larisse Neumann, Juliane Schossler Lopes, Angela Sansson, Daniela Da Rocha Estácio, Lucas Ost Duarte, Patricia Sbaraini, Ana Maria Marques da Silva, and Elaine Evani Streck. "Elaboração e Implementação de Procedimentos Operacionais Padrão para Controle de Qualidade da Imagem CBCT em Radioterapia." Revista Brasileira de Física Médica 10, no. 3 (December 31, 2016): 21. http://dx.doi.org/10.29384/rbfm.2016.v10.n3.p21-27.

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O objetivo deste artigo é apresentar a implementação do controle de qualidade da imagem de tomografia computadorizada por feixe cônico (CBCT), gerada pelo dispositivo On-Board Imager, integrado ao acelerador linear Trilogy. Para tal, foram elaborados procedimentos operacionais padrão (POP) com base na literatura e nos manuais do objeto simulador Catphan 504 e do On-Board Imager. Foram elaborados os seguintes POP: aquisição da imagem CBCT; linearidade do número de CT; uniformidade; resolução espacial; resolução de baixo contraste; linearidade espacial; espessura do corte. A validação dos procedimentos elaborados foi realizada a partir de uma aquisição experimental do objeto simulador. Os resultados obtidos na validação dos POP estão em conformidade com os parâmetros estabelecidos pelo fabricante do objeto simulador, assim como aqueles obtidos na aceitação do dispositivoOn-Board Imager.
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12

Ferretti, A., F. Pietrobon, M. Serafini, L. Gallo, and E. Bolla. "Standardized evaluation of CT image quality: A comparison between three widespread software packages for automated CATPHAN analysis." Physica Medica 32 (February 2016): 78. http://dx.doi.org/10.1016/j.ejmp.2016.01.266.

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13

Annkah, JamesKwame, Naina Hindocha, SyedAli Moinuddin, Kate Ricketts, Ivan Rosenberg, Gary Royle, and Abiodun Adeyemi. "Assessment of the dosimetric accuracies of CATPhan 504 and CIRS 062 using kV-CBCT for performing direct calculations." Journal of Medical Physics 39, no. 3 (2014): 133. http://dx.doi.org/10.4103/0971-6203.139001.

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14

Won, Hui-Su, Jin-Beom Chung, Byung-Don Choi, Jin-Hong Park, and Do-Guwn Hwang. "Accuracy of automatic matching of Catphan 504 phantom in cone-beam computed tomography for tube current-exposure time product." Journal of Applied Clinical Medical Physics 17, no. 6 (November 2016): 421–28. http://dx.doi.org/10.1120/jacmp.v17i6.6402.

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15

Miloudi, H., T. Bui, S. Fayolle, L. Gonzalez, B. Royer, A. Noel, F. Dufay, and S. Amir. "Optimisation d’un protocole rochers au scanner." Radioprotection 53, no. 1 (January 2018): 21–25. http://dx.doi.org/10.1051/radiopro/2017040.

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Cette étude vise à optimiser le protocole des rochers d’un scanner Siemens Somatom Sensation 40. Ainsi, plusieurs acquisitions du fantôme Catphan 600 sont réalisées pour évaluer quantitativement la qualité d’image. Pour cela, l’écart type du nombre CT et la fonction de transfert de modulation (FTM) sont mesurés à partir des images acquises. La qualité d’image est également évaluée visuellement par le radiologue, à partir d’images issues de patients. Trois critères sont considérés : la visualisation du tympan, la visualisation des osselets et la texture du bruit. L’utilisation de la table plutôt que de la têtière comme support conduit à une augmentation moyenne du bruit de 10 %. L’évaluation qualitative des images issues de patients a permis quant à elle de réduire les mAs effectifs de 28 % et donc l’IDSV de 150,8 mGy à 109,1 mGy. De plus, l’utilisation d’un filtre plus dur a conduit à une amélioration de la visualisation des plus petites structures de l’oreille interne. Ainsi, cette étude a permis d’assurer une qualité d’image satisfaisante pour le diagnostic tout en réduisant la dose délivrée au patient de 28 %.
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Abdullah, Kamarul A., Mark F. McEntee, Warren M. Reed, and Peter L. Kench. "Increasing iterative reconstruction strength at low tube voltage in coronary CT angiography protocols using 3D‐printed and Catphan ® 500 phantoms." Journal of Applied Clinical Medical Physics 21, no. 9 (July 13, 2020): 209–14. http://dx.doi.org/10.1002/acm2.12977.

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17

Srivastava, Roopam, Shiva Gaur, Pramod Sharma, Manoj Sharma, Jayanand Manjhi, Maria Das, Dr Deepika Chauhan, and Dr Neha Sehgal. "Site Specific Calibration Curve And Its Implication in The Treatment Planning of Head And Neck Cancer." JOURNAL OF ADVANCES IN PHYSICS 17 (January 11, 2020): 1–5. http://dx.doi.org/10.24297/jap.v17i.8538.

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Purpose: In this study, we created site specific Hounsfield Unit (HU) and Relative electron density(RED) calibration curves for computed tomography(CT) and cone beam computed tomography (CBCT) for head and neck radiotherapy dose calculation and compared them with standard calibration curves. Methods: The calibration curves between HU and RED were generated using RANDO phantom for CT and CBCT and fed in the treatment planning system for dose calculation for head and neck patients.The treatment plans for 10 head and neck cancer patients were calculated using the standard calibration curves generated with CATPHAN and head and neck calibration curves generated with RANDO phantom for both CT and CBCT. Dose accuracy of head and neck calibration curves(H/N CC) were compared to the standard calibration curves (SCC) using dose volume metrics and 3D gamma analysis. Results: The results show that slightly better dosimetric agreement from the SCC can be obtained when using this H/N CC. Conclusions: A site specific calibration curves have been proposed and tested for the head-and-neck patients and the results explain the dosimetric benefits.
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Kashani, Hany, Graham Wright, Ali Ursani, Garry Liu, Masoud Hashemi, and Narinder Paul. "Restricting motion effects in CT coronary angiography." British Journal of Radiology 92, no. 1103 (November 2019): 20190384. http://dx.doi.org/10.1259/bjr.20190384.

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Objective: Evaluation of coronary CT image blur using multi segment reconstruction algorithm. Methods: Cardiac motion was simulated in a Catphan. CT coronary angiography was performed using 320 × 0.5 mm detector array and 275 ms gantry rotation. 1, 2 and 3 segment reconstruction algorithm, three heart rates (60, 80 and 100bpm), two peak displacements (4, 8 mm) and three cardiac phases (55, 35, 75%) were used. Wilcoxon test compared image blur from the different reconstruction algorithms. Results: Image blur for 1, 2 and 3 segments in: 60 bpm, 75% R–R interval and 8 mm peak displacement: 0.714, 0.588, 0.571 mm (1.18, 0.6, 0.4 mm displacement) 80 bpm, 35% R–R interval and 8 mm peak displacement: 0.869, 0.606, 0.606 mm (1.57, 0.79,0.52 mm displacement) 100 bpm, 35% R–R interval and 4 mm peak displacement: 0.645, 0.588, 0.571 mm (0.98, 0.49, 0.33 mm displacement). The median image blur overall for 1 and 2 segments was 0.714 mm and 0.588 mm respectively (p < 0.0001). Conclusion: Two-segment reconstruction significantly reduces image blur. Advances in knowledge: Multisegment reconstruction algorithms during CT coronary angiography are a useful method to reduce image blur, improve visualization of the coronary artery wall and help the early detection of the plaque.
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Kim, Hae Young, Kyeorye Lee, Won Chang, Youngjune Kim, Sungsoo Lee, Dong Yul Oh, Leonard Sunwoo, Yoon Jin Lee, and Young Hoon Kim. "Robustness of Deep Learning Algorithm to Varying Imaging Conditions in Detecting Low Contrast Objects in Computed Tomography Phantom Images: In Comparison to 12 Radiologists." Diagnostics 11, no. 3 (February 28, 2021): 410. http://dx.doi.org/10.3390/diagnostics11030410.

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The performance of deep learning algorithm (DLA) to that of radiologists was compared in detecting low contrast objects in CT phantom images under various imaging conditions. For training, 10,000 images were created using American College of Radiology CT phantom as the background. In half of the images, objects of 3–20 mm size and 5–30 HU contrast difference were generated in random locations. Binary responses were used as the ground truth. For testing, 640 images of Catphan® phantom were used, half of which had objects of either 5 or 9 mm size with 10 HU contrast difference. Twelve radiologists evaluated the presence of objects on a five-point scale. The performances of the DLA and radiologists were compared across different imaging conditions in terms of area under receiver operating characteristics curve (AUC). Multi-reader multi-case AUC and Hanley and McNeil tests were used. We performed post-hoc analysis using bootstrapping and verified that the DLA is less affected by the changing imaging conditions. The AUC of DLA was consistently higher than those of the radiologists across different imaging conditions (p < 0.0001), and it was less affected by varying imaging conditions. The DLA outperformed the radiologists and showed more robust performance under varying imaging conditions.
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Gopal, A., and S. Samant. "SU-GG-I-115: Characterization of Clinical CBCT and MVCT Systems Based On Fundamental MTF, NPS and DQE Measurements Using a Conventional CatPhan Phantom." Medical Physics 35, no. 6Part4 (June 2008): 2668. http://dx.doi.org/10.1118/1.2961513.

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21

Dong, Xue, Michael Petrongolo, Tianye Niu, and Lei Zhu. "Low-Dose and Scatter-Free Cone-Beam CT Imaging Using a Stationary Beam Blocker in a Single Scan: Phantom Studies." Computational and Mathematical Methods in Medicine 2013 (2013): 1–8. http://dx.doi.org/10.1155/2013/637614.

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Excessive imaging dose from repeated scans and poor image quality mainly due to scatter contamination are the two bottlenecks of cone-beam CT (CBCT) imaging. Compressed sensing (CS) reconstruction algorithms show promises in recovering faithful signals from low-dose projection data but do not serve well the needs of accurate CBCT imaging if effective scatter correction is not in place. Scatter can be accurately measured and removed using measurement-based methods. However, these approaches are considered unpractical in the conventional FDK reconstruction, due to the inevitable primary loss for scatter measurement. We combine measurement-based scatter correction and CS-based iterative reconstruction to generate scatter-free images from low-dose projections. We distribute blocked areas on the detector where primary signals are considered redundant in a full scan. Scatter distribution is estimated by interpolating/extrapolating measured scatter samples inside blocked areas. CS-based iterative reconstruction is finally carried out on the undersampled data to obtain scatter-free and low-dose CBCT images. With only 25% of conventional full-scan dose, our method reduces the average CT number error from 250 HU to 24 HU and increases the contrast by a factor of 2.1 on Catphan 600 phantom. On an anthropomorphic head phantom, the average CT number error is reduced from 224 HU to 10 HU in the central uniform area.
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Szweda, Hubert. "Testy kontroli jakości obrazowania kV-CBCT z wykorzystaniem fantomu Capthan 504 oraz ich analiza z użyciem oprogramowania Artiscan." Letters in Oncology Science 17, no. 1 (March 20, 2020): 41–50. http://dx.doi.org/10.21641/los.2020.17.1.164.

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Radioterapia kontrolowana za pomocą obrazowania (ang. Image Guided Radiotherapy – IGRT) w ostatnich latach stała się szeroko akceptowalną i zalecaną techniką leczenia. Możliwość precyzyjnego obrazowania pacjenta bezpośrednio przed podaniem wiązki terapeutycznej pozwala na bardzo dokładne sprawdzenie jego ułożenia, precyzyjne napromienienie obszaru tarczowego oraz zmniejszenie dawki promieniowania deponowanej w zdrowych tkankach i narządach. Głównym celem pracy było wykonanie testów kontroli jakości systemu obrazowania kV-CBCT zainstalowanego na medycznym akceleratorze liniowym TrueBeam, firmy Varian Medical Systems. Celem szczegółowym było wyznaczenie wartości referencyjnych dla wszystkich testów obrazowania oraz opracowanie protokołów QA (ang. Quality Assurance). Do przeprowadzenia testów kontroli jakości wykorzystano fantom Catphan 504. Dokonano kontroli jakości dwóch protokołów skanowania: Head oraz Pelvis. Podczas testów wyznaczono następujące parametry opisujące jakość obrazu: liniowość skali jednostek Hounsfielda, rozdzielczość wysokokontrastową, rozdzielczość niskokontrastową, zniekształcenie geometryczne, poziom szumu, jednorodność. Do analizy uzyskanych obrazów DICOM wykorzystano oprogramowanie Artiscan. Poziom szumu w obrazie wynosił 2,75% dla protokołu skanowania Head i 0,85% dla protokołu Pelvis, natomiast jednorodność obrazu wynosiła 94% i 98%. Wszystkie obliczone wartości jednostek HU mieściły się w przyjętym przedziale tolerancji. Rozdzielczość wysokokontrastowa wynosiła kolejno 7,70lp/mm i 5,59lp/mm. Dla protokołu skanowania Pelvis, obiekt o średnicy 15mm w warunkach Supra-Slice 1% został wykryty podczas każdej serii pomiarowej. Nie zaobserwowano żadnych zniekształceń geometrycznych obrazu. Opracowane protokoły kontroli jakości używane są w praktyce klinicznej podczas procesu kontroli jakości.
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Filippini Meletti, Amanda, Cristiane Barsanelli, Victor Augusto Bertotti Ribeiro, Paulo De Tarso Dalledone Siqueira, Hélio Yoriyaz, Julian Marco Barbosa Shorto, and Maira Goes Nunes. "Levantamento da curva CT-to-ED para CBCT e seu uso na estimativa de dose em tratamento radioterápico de próstata." Revista Brasileira de Física Médica 14 (December 21, 2020): 574. http://dx.doi.org/10.29384/rbfm.2020.v14.19849001574.

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A fim de estimar a dose em pacientes em tratamento radioterápico de próstata, foi levantada a curva CT-to-ED para o sistema kv-CBCT XVI da Elekta e aplicado um método de sua correção para a região específica da pelve. O levantamento da curva foi feita por meio dos fantomas CatPhan® 503 e CIRS Pelvic e, para a sua correção, foram utilizadas as imagens de CBCT de 8 pacientes selecionados. A curva foi validada por meio de comparações entre a qualidade dos planejamentos calculados na Tomografia de Referência e na Tomografia de Feixe Cônico. Foram avaliados os histogramas de dose-volume (DVHs) e as distribuições de dose pelo critério gama – 3% e 3mm nos casos VMAT e 2% e 2mm nos 3D. Após a correção da curva, a diferença do cálculo da dose entre a CBCT e a CT de referência diminuiu, em média, de 4,7%±0,8% para 1,7%±1,1% nos planejamentos VMAT e de 3,2%±1,7% para 1,9%±1,6% nos planejamentos 3D. As aprovações nas análises gama subiram, em média, de 80,6%±3,5% para 99,1%±0,5% (VMAT) e de 84,3%±4,2% para 98,9%±1,0% (3D). Uma vez garantida a acurácia do cálculo na CBCT, a curva pode ser utilizada para verificar se a dose diariamente entregue ao paciente condiz com aquela que foi planejada e, caso contrário, ele pode ser beneficiado de replanejamento (e de compensação da dose) nas frações remanescentes de seu tratamento.
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Sakai, Yuki, Kazutoshi Okamura, Erina Kitamoto, Yukiko N. Kami, Takashi Shirasaka, Ryoji Mikayama, Masato Tatsumi, Masatoshi Kondo, Toyoyuki Kato, and Kazunori Yoshiura. "Improved scan method for dental imaging using multidetector computed tomography: a phantom study." Dentomaxillofacial Radiology 49, no. 6 (September 1, 2020): 20190462. http://dx.doi.org/10.1259/dmfr.20190462.

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Objectives: This study aimed to propose an improved scan method to shorten irradiation time and reduce radiation exposure. Methods: The maxilla of a human head CT phantom and a Catphan phantom were used for qualitative and quantitative assessment, respectively. The phantoms were scanned by a 160-row multidetector CT scanner using volumetric and helical scanning. In volumetric scanning, the tube current varied from 120 to 60 to 30 to 20 mA with a tube voltage of 120 kV. Images were reconstructed with a bone kernel using iterative reconstruction (IR) and filtered back projection. As a reference protocol, helical scanning was performed using our clinical setting with 120 kV. Two dental radiologists independently graded the quality of dental images using a 4-point scale (4, superior to reference; 1, unacceptable). For the quantitative assessment, we assessed the system performance from each scan. Results: There was no significant difference between the image quality of volumetric scanning using the 60 mA protocol reconstructed with IR and that of the reference (3.08 and 3.00, p = 0.3388). The system performance values at 1.0 cycles/mm of volumetric scanning and 60 mA protocol reconstructed with IR and reference were 0.0038 and 0.0041, respectively. The effective dose of volumetric scanning using the 60 mA protocol was 51.8 µSv, which is a 64.2% reduction to that of the reference. Conclusions: We proposed an improved scan method resulting in a 64.2% reduction of radiation dose with one-fourth of irradiation time by combining volumetric scanning and IR technique in multidetector CT.
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Aurumskjöld, Marie-Louise, Kristina Ydström, Anders Tingberg, and Marcus Söderberg. "Improvements to image quality using hybrid and model-based iterative reconstructions: a phantom study." Acta Radiologica 58, no. 1 (July 19, 2016): 53–61. http://dx.doi.org/10.1177/0284185116631180.

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Background The number of computed tomography (CT) examinations is increasing and leading to an increase in total patient exposure. It is therefore important to optimize CT scan imaging conditions in order to reduce the radiation dose. The introduction of iterative reconstruction methods has enabled an improvement in image quality and a reduction in radiation dose. Purpose To investigate how image quality depends on reconstruction method and to discuss patient dose reduction resulting from the use of hybrid and model-based iterative reconstruction. Material and Methods An image quality phantom (Catphan® 600) and an anthropomorphic torso phantom were examined on a Philips Brilliance iCT. The image quality was evaluated in terms of CT numbers, noise, noise power spectra (NPS), contrast-to-noise ratio (CNR), low-contrast resolution, and spatial resolution for different scan parameters and dose levels. The images were reconstructed using filtered back projection (FBP) and different settings of hybrid (iDose4) and model-based (IMR) iterative reconstruction methods. Results iDose4 decreased the noise by 15–45% compared with FBP depending on the level of iDose4. The IMR reduced the noise even further, by 60–75% compared to FBP. The results are independent of dose. The NPS showed changes in the noise distribution for different reconstruction methods. The low-contrast resolution and CNR were improved with iDose4, and the improvement was even greater with IMR. Conclusion There is great potential to reduce noise and thereby improve image quality by using hybrid or, in particular, model-based iterative reconstruction methods, or to lower radiation dose and maintain image quality.
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Okumura, Miwa, Takamasa Ota, Kazuhisa Kainuma, James W. Sayre, Michael McNitt-Gray, and Kazuhiro Katada. "Effect of Edge-Preserving Adaptive Image Filter on Low-Contrast Detectability in CT Systems: Application of ROC Analysis." International Journal of Biomedical Imaging 2008 (2008): 1–6. http://dx.doi.org/10.1155/2008/379486.

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Objective. For the multislice CT (MSCT) systems with a larger number of detector rows, it is essential to employ dose-reduction techniques. As reported in previous studies, edge-preserving adaptive image filters, which selectively eliminate only the noise elements that are increased when the radiation dose is reduced without affecting the sharpness of images, have been developed. In the present study, we employed receiver operating characteristic (ROC) analysis to assess the effects of the quantum denoising system (QDS), which is an edge-preserving adaptive filter that we have developed, on low-contrast resolution, and to evaluate to what degree the radiation dose can be reduced while maintaining acceptable low-contrast resolution.Materials and Methods. The low-contrast phantoms (Catphan 412) were scanned at various tube current settings, and ROC analysis was then performed for the groups of images obtained with/without the use of QDS at each tube current to determine whether or not a target could be identified. The tube current settings for which the area under the ROC curve (Az value) was approximately 0.7 were determined for both groups of images with/without the use of QDS. Then, the radiation dose reduction ratio when QDS was used was calculated by converting the determined tube current to the radiation dose.Results. The use of the QDS edge-preserving adaptive image filter allowed the radiation dose to be reduced by up to 38%.Conclusion. The QDS was found to be useful for reducing the radiation dose without affecting the low-contrast resolution in MSCT studies.
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Barca, Patrizio, Daniela Marfisi, Chiara Marzi, Sabino Cozza, Stefano Diciotti, Antonio Claudio Traino, and Marco Giannelli. "A Voxel-Based Assessment of Noise Properties in Computed Tomography Imaging with the ASiR-V and ASiR Iterative Reconstruction Algorithms." Applied Sciences 11, no. 14 (July 16, 2021): 6561. http://dx.doi.org/10.3390/app11146561.

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Given the inherent characteristics of nonlinearity and nonstationarity of iterative reconstruction algorithms in computed tomography (CT) imaging, this study aimed to perform, for the first time, a voxel-based characterization of noise properties in CT imaging with the ASiR-V and ASiR algorithms as compared with conventional filtered back projection (FBP). Multiple repeated scans of the Catphan-504 phantom were carried out. CT images were reconstructed using FBP and ASiR/ASiR-V with different blending levels of reconstruction (20%, 40%, 60%, 80%, 100%). Noise maps and their nonuniformity index (NUI) were obtained according to the approach proposed by the report of AAPM TG-233. For the homogeneous CTP486 module, ASiR-V/ASiR allowed a noise reduction of up to 63.7%/52.9% relative to FBP. While the noise reduction values of ASiR-V-/ASiR-reconstructed images ranged up to 33.8%/39.9% and 31.2%/35.5% for air and Teflon contrast objects, respectively, these values were approximately 60%/50% for other contrast objects (PMP, LDPE, polystyrene, acrylic, Delrin). Moreover, for all contrast objects but air and Teflon, ASiR-V showed a greater noise reduction potential than ASiR when the blending level was ≥40%. While noise maps of the homogenous CTP486 module showed only a slight spatial variation of noise (NUI < 5.2%) for all reconstruction algorithms, the NUI values of iterative-reconstructed images of the nonhomogeneous CTP404 module increased nonlinearly with blending level and were 19%/15% and 6.7% for pure ASiR-V/ASiR and FBP, respectively. Overall, these results confirm the potential of ASiR-V and ASiR in reducing noise as compared with conventional FBP, suggesting, however, that the use of pure ASiR-V or ASiR might be suboptimal for specific clinical applications.
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Lebedenko, I., B. Gavrikov, and T. Borisova. "Method of Quatitative Evaluation of the Size and Density of the Tumor During Adaptive Radiotherapy Using CT Images." Medical Radiology and radiation safety 64, no. 6 (November 10, 2019): 64–69. http://dx.doi.org/10.12737/1024-6177-2019-64-6-64-69.

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Purpose: Clinically available quantitative method for assessing the dynamics of the size and physical density (in g/cm3) of the tumor in adaptive radiotherapy for cancer patients and any cases of visualization of tumor boundaries including the cases when the border of a tumor is not clearly visualized. Material and methods: A preliminary analysis of the images transmitted over the CT network was carried out in the Eclipse planning system (PS). The radiotherapy treatment planning using electron accelerators with a multi-leaf collimator( Varian (USA)) was carried out at the Eclipse PS. The image quality control of Light Speed RT 16 (manufactured by GE) X-ray computed tomography scanner was performed using the multi-modular phantom Catphan® 504. The assessment of the densitometric characteristics CT imaging made using eight tissue-equivalent a test object with mass densities from 0.03 to 1.37 g/cm3 which corresponding to the density of biological tissues of the human body. To quantify the size and density of the tumor in a dynamic mode, we have written and used our own Matlab program installed on a separate computer. For lossless compression of graphic information, the PNG-image scale (raster graphic information storage format) is used, which is equivalent to the scale of the original DICOM file at the Eclipse PS. A program consists of subroutines that include calibration, contour integration, and integration along a horizontal line. Results: The quantitative information content of the method is shown. The method is used in clinical practice. Conclusions: A clinically available quantitative method for assessing dynamics of the size and physical density of the tumor has been developed and proposed for use in adaptive radiatiotherapy for cancer patients for any cases of visualization of tumor boundaries. When a positive dynamics in the tumor, the integral index is greater than 1 (M > 1), when a negative dynamics (in the absence of response to treatment) M ≤ 1. Quantitative characteristics are objective, do not depend on the subjective assessments of personnel and can serve as a basis for rescheduling exposure plans.
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Barca, Patrizio, Fabio Paolicchi, Giacomo Aringhieri, Federica Palmas, Daniela Marfisi, Maria Evelina Fantacci, Davide Caramella, and Marco Giannelli. "A comprehensive assessment of physical image quality of five different scanners for head CT imaging as clinically used at a single hospital centre—A phantom study." PLOS ONE 16, no. 1 (January 14, 2021): e0245374. http://dx.doi.org/10.1371/journal.pone.0245374.

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Nowadays, given the technological advance in CT imaging and increasing heterogeneity in characteristics of CT scanners, a number of CT scanners with different manufacturers/technologies are often installed in a hospital centre and used by various departments. In this phantom study, a comprehensive assessment of image quality of 5 scanners (from 3 manufacturers and with different models) for head CT imaging, as clinically used at a single hospital centre, was hence carried out. Helical and/or sequential acquisitions of the Catphan-504 phantom were performed, using the scanning protocols (CTDIvol range: 54.7–57.5 mGy) employed by the staff of various Radiology/Neuroradiology departments of our institution for routine head examinations. CT image quality for each scanner/acquisition protocol was assessed through noise level, noise power spectrum (NPS), contrast-to-noise ratio (CNR), modulation transfer function (MTF), low contrast detectability (LCD) and non-uniformity index analyses. Noise values ranged from 3.5 HU to 5.7 HU across scanners/acquisition protocols. NPS curves differed in terms of peak position (range: 0.21–0.30 mm-1). A substantial variation of CNR values with scanner/acquisition protocol was observed for different contrast inserts. The coefficient of variation (standard deviation divided by mean value) of CNR values across scanners/acquisition protocols was 18.3%, 31.4%, 34.2%, 30.4% and 30% for teflon, delrin, LDPE, polystyrene and acrylic insert, respectively. An appreciable difference in MTF curves across scanners/acquisition protocols was revealed, with a coefficient of variation of f50%/f10% of MTF curves across scanners/acquisition protocols of 10.1%/7.4%. A relevant difference in LCD performance of different scanners/acquisition protocols was found. The range of contrast threshold for a typical object size of 3 mm was 3.7–5.8 HU. Moreover, appreciable differences in terms of NUI values (range: 4.1%-8.3%) were found. The analysis of several quality indices showed a non-negligible variability in head CT imaging capabilities across different scanners/acquisition protocols. This highlights the importance of a physical in-depth characterization of image quality for each CT scanner as clinically used, in order to optimize CT imaging procedures.
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Bauer, G., M. Nieger, and D. Gudat. "Heterobimetallic catechol-phosphine complexes with palladium and a group-13 element: structural flexibility and dynamics." Dalton Trans. 43, no. 23 (2014): 8911–20. http://dx.doi.org/10.1039/c4dt00785a.

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Condensation of a catechol phosphine Pd complex [Pd(catphosH)2] with group-13 element acetylacetonates yields complexes [M(L)n(catphos)2Pd] or [M{(catphos)2Pd}2]H (M = Al, Ga, In) whose relative stability is controlled by the size of the group-13 element. 1H NMR studies give insight into the proton mobility in a Pd2In complex.
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Doerfel, Marya L., and George A. Barnett. "The Use of CATPAC for Text Analysis." CAM Journal 8, no. 2 (May 1996): 4–7. http://dx.doi.org/10.1177/1525822x960080020501.

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Linting, Mariëlle, and Anita van der Kooij. "Nonlinear Principal Components Analysis With CATPCA: A Tutorial." Journal of Personality Assessment 94, no. 1 (January 2012): 12–25. http://dx.doi.org/10.1080/00223891.2011.627965.

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Saputri, Winda Luvi, and Timbang Sirait. "PENGHITUNGAN INDEKS KOMPOSIT DAYA SAING DESA/KELURAHAN MENGGUNAKAN CATPCA." Seminar Nasional Official Statistics 2019, no. 1 (May 13, 2020): 255–65. http://dx.doi.org/10.34123/semnasoffstat.v2019i1.69.

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Pembangunan wilayah Indonesia penting dilakukan untuk meningkatkan kesejahteraan masyarakat Indonesia. Menurut UU No. 6 tahun 2014 tentang desa menyebutkan bahwa pembangunan wilayah Indonesia berbasis desa dijadikan sebagai salah satu upaya memerkuat fundamental perekonomian. Tingkat daya saing (competitiveness) merupakan salah satu parameter dalam konsep pembangunan berkelanjutan di suatu wilayah. Penelitian ini difokuskan untuk mengkaji daya saing desa/kelurahan di Provinsi Jawa Timur untuk mengetahui apakah daya saing Provinsi Jawa Timur yang baik ditunjang oleh daya saing desa/kelurahannya yang memang baik serta untuk mengetahui apakah terjadi ketidakmerataan daya saing desa/kelurahan di Provinsi Jawa Timur. Indeks komposit daya saing desa/kelurahan (IDD) dibentuk untuk mengetahui kondisi daya saing masing-masing desa/kelurahan di Jawa Timur. Teknik analisis multivariat CATPCA dipakai dalam pembentukan bobot untuk IDD. Nilai indeks daya saing desa/kelurahan yang terbentuk berkisar antara 31,98 hingga 92,37. Rata-rata indeks daya saing desa/kelurahan di Provinsi Jawa Timur sebesar 58,49 atau termasuk kategori sedang. Rata-rata IDD kota umumnya lebih tinggi daripada IDD kabupaten, namun ketidakmerataan nilai IDD lebih parah di kabupaten. Rata-rata IDD di kelurahan lebih tinggi daripada di desa, namun ketidakmerataan nilai IDD lebih parah di desa. Dimensi yang perlu dibenahi adalah dimensi keuangan, pendidikan, dan kesehatan. Korelasi antara IDD dan IPD cukup tinggi dan positif yaitu 0,77.
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Bünz, D., and K. Gütschow. "CATPAC—An interactive software package for control system design." Automatica 21, no. 2 (March 1985): 209–13. http://dx.doi.org/10.1016/0005-1098(85)90116-5.

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Politino, Virginia, and Sarah L. Smith. "Attitude Toward Physical Activity and Self-Concept of Emotionally Disturbed and Normal Children." Adapted Physical Activity Quarterly 6, no. 4 (October 1989): 371–78. http://dx.doi.org/10.1123/apaq.6.4.371.

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This study investigated the relationship between attitude toward physical activity and self-concept of emotionally disturbed and normal children. The subjects were 470 boys and girls, ranging from 8 to 13 years of age (M = 10.95, SD = 1.91). The sample included 80 emotionally disturbed children from two psychiatric hospitals in Ohio and 390 normal children from a parochial school in Ohio. Data were collected through the Children’s Attitude Toward Physical Activity Inventory (CATPA) and the Piers-Harris Self-Concept Scale. A significant difference on CATPA occurred between emotionally disturbed and normal children and between boys and girls. A two-way ANOVA revealed a significant difference in self-concept between emotionally disturbed and normal children. The Pearson product-moment correlation revealed low but significant relationships between self-concept and the following subscales of the CATPA: social experience, thrill, and release of tension. The results indicated that normal children had a more positive attitude toward physical activity and self-concept than emotionally disturbed children.
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Jiménez, Rafael, Elena Gervilla, Albert Sesé, Juan José Montaño, Berta Cajal, and Alfonso Palmer. "Dimensionality Reduction in Data Mining Using Artificial Neural Networks." Methodology 5, no. 1 (January 2009): 26–34. http://dx.doi.org/10.1027/1614-2241.5.1.26.

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The use of classic dimension reduction techniques can be considered customary practice within the context of data mining (DM). Nevertheless, although artificial neural networks (ANNs) are one of the most important DM techniques, specific ANN architectures for dimensionality reduction, such as the principal components analysis ANN (PCA-ANN) and the linear auto-associative ANN (LA-ANN), are used on far fewer occasions. In this study, categorical principal component analysis (CATPCA) and the two ANN procedures are studied and compared searching for uniqueness in an applied context relative to personality variables and drug consumption. A sample of 7,030 adolescents completed a personality test made up of 20 dichotomous items with a hypothesized four-factor latent model. Results point out that both ANN factor solutions converge to those obtained using CATPCA. Nevertheless, possible drawbacks of the ANN techniques lie in their relatively complex application, as well as in the need to use visual graphic analysis as a support for interpreting the factorized solutions.
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Hagger, Martin, Lorraine Cale, and Len Almond. "Children's Physical Activity Levels and Attitudes Towards Physical Activity." European Physical Education Review 3, no. 2 (October 1997): 144–64. http://dx.doi.org/10.1177/1356336x9700300205.

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This study investigated the relationship between attitude towards physical activity and physical activity behaviour and the influence of gender and season on physical activity level in 45 primary school children, aged 9 to 11 years. Attitudes towards physical activity were assessed using two different theoretical approaches: the children's attitudes towards physical activity (CATPA) inventory and the theory of reasoned action (TRA) questionnaire. Physical activity behaviour was measured using Cale's (1994) self-report measure of physical activity. Approximately 50% of the children were categorised as 'inactive' based on cut-off points developed by Blair (1984). A 2 x 2 (gender x season) factorial analysis of variance showed that children partici pated in more moderate physical activity in the summer than in the winter (F(1,44) = 6.29, p<.05) but there were no gender differences in physical activity levels. Descriptive statistics for the CATPA inventory showed that children generally exhibited positive attitudes towards physical activity. Mann-Whitney U tests for two independent samples revealed significant differences between the high-active and low-active children for the catharsis, health and fitness, vertigo and aesthetic subdomains from the CATPA inventory (p<.05). None of the TRA variables showed any significant differences for activity level. Present results suggest that some attitude variables from the CATPA inventory differ according to children's physical activity levels and thereby emphasise the need for physical educators to foster positive attitudes towards physical activity in order to encourage children to adopt and maintain healthy and active lifestyles.
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Zopp, Camilo, Daisy Nestler, Jürgen Tröltzsch, Maik Trautmann, Sebastian Nendel, Guntram Wagner, Wolfgang Nendel, and Lothar Kroll. "CATPUAL - An Innovative and High-Performance Hybrid Laminate with Carbon Fibre-Reinforced Thermoplastic Polyurethane." Key Engineering Materials 742 (July 2017): 294–301. http://dx.doi.org/10.4028/www.scientific.net/kem.742.294.

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In consideration of environmental aspects and limited availability of resources, the focus of automotive and aerospace industry lies on significant weight optimisations especially for moving loads. In this context, innovative lightweight materials as well as material combinations need to be developed. A considerable potential for lightweight structures can be found in fibre- or textile-reinforced semi-finished products. Due to their specific characteristics and extraordinary structural diversity, thermoset and thermoplastic matrix systems can be used. In particular, carbon fibres as reinforcing components combined with a thermoplastic matrix polymer are able to create new high-performance applications. Besides the significant lightweight characteristics of the fibre-plastic-composites, in some instances contrary requirements must be satisfied in many areas, such as strength and ductility. In this field, the combination of fibre-reinforced polymers with aluminium or titanium sheets creates unique composite materials, so called hybrid laminates, which fulfil the unusual expectations.The focus of the current study lies on the development of a new thermoplastic hybrid laminate named CATPUAL (CArbon fibre-reinforced Thermoplastic PolyUrethane/ALuminium laminate). The structure of the laminate is an alternating sequence of thin aluminium sheets (EN AW 6082-T4) and fibre-reinforced thermoplastic polyurethane (TPU). The individual layers are consolidated to each other by using a hot pressing process. First results showed that the impregnation capability of thermoplastic polyurethane surpasses any other commercially available hybrid laminates. Furthermore, the mechanical properties regarding bending strength and interlaminar shear strength are exceeding the state of the art drastically.
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Khikmah, L., H. Wijayanto, and U. D. Syafitri. "Modeling Governance KB with CATPCA to Overcome Multicollinearity in the Logistic Regression." Journal of Physics: Conference Series 824 (April 18, 2017): 012027. http://dx.doi.org/10.1088/1742-6596/824/1/012027.

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Saukani, Nasir, and Noor Azina Ismail. "Identifying the Components of Social Capital by Categorical Principal Component Analysis (CATPCA)." Social Indicators Research 141, no. 2 (January 31, 2018): 631–55. http://dx.doi.org/10.1007/s11205-018-1842-2.

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Vega-Dienstmaier, Johann M., J. Martín Arévalo-Flores, J. David Tomateo-Torvisco, and Emilio Cabello. "Validación de un instrumento para evaluar la satisfacción de los usuarios atendidos en el consultorio externo de psiquiatría de un hospital público (Lima, Perú)." Revista de Neuro-Psiquiatria 77, no. 4 (December 29, 2014): 271. http://dx.doi.org/10.20453/rnp.v77i4.2196.

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Objetivo: Validar un instrumento para evaluar la satisfacción de los usuarios de la consulta externa de psiquiatría. Método: A partir del contenido de otros instrumentos para evaluar la satisfacción de los pacientes con su atención, de la opinión de un grupo de psiquiatras y de la información que se obtuvo al aplicar una primera versión de la escala a 40 usuarios de consultorio de psiquiatría, se construyó una segunda versión autoadministrable, la cual fue evaluada en cuanto a claridad y relevancia de los ítems, consistencia interna, análisis de componentes principales para variables categóricas (CATPCA) y convergencia con la misma segunda versión pero administrada por entrevista. Resultados: La opinión sobre las preguntas del cuestionario por parte de usuarios y médicos fue en general favorable. El alfa de Cronbach fue 0,828. El CATPCA permitió identificar 3 factores relacionados con: 1) el acto médico, 2) la organización y 3) la comodidad y espera; siendo el primero el más importante. La correlación del puntaje total de la versión autoadministrable y la versión por entrevista fue 0,876 (p<0,0001). Conclusiones: Este estudio inicial realizado en consultorio de psiquiatría, muestra que esta nueva escala para evaluar satisfacción del usuario tiene características psicométricas adecuadas.
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Hamidi, M. Luthfi, and Andrew C. Worthington. "Islamic banking sustainability: theory and evidence using a novel quadruple bottom line framework." International Journal of Bank Marketing 39, no. 5 (March 4, 2021): 751–67. http://dx.doi.org/10.1108/ijbm-06-2020-0345.

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PurposeThe study aims to extend the conventional triple bottom line (TBL) framework (prosperity, people and planet) to the quadruple bottom line (QBL) by newly adding a “prophet” dimension for Islamic banks seeking compliance with Islamic law in their pursuit of sustainability.Design/methodology/approachEmploy Chapra's corollaries of maqasid al-shari'ah (the goals of Islamic law) to develop constructs for a survey of 504 Islamic bank stakeholders from five Indonesian provinces to gather primary data to quantitatively verify the dimensions and items in the proposed QBL framework. Categorical principal component analysis (CATPCA) then identifies the sustainability of ten Islamic banks from ten countries as a trial application of the resulting QBL index.FindingsUsing the dimensions and items identified using CATPCA, the authors develop a QBL index to assess the sustainability of the ten Islamic banks. The findings suggest that half of the banks are sufficiently sustainable, with three being proactive (doing more than is required) and two being accommodative (doing all that is required). The remaining five banks are unsustainable, with two banks being defensive (doing the least that is required) and three being reactive (doing less than is required). Most of the banks perform relatively poorly according to the “planet” (38%) and “people” (41%) dimensions and perform better on the “prosperity” (53%) and “prophet” (63%) dimensions. Nonetheless, there is ample room for improvement across all dimensions of sustainability.Research limitations/implicationsThe generalizability of the findings is limited by the small-scale single-country survey used in the CATPCA part of the analysis. Only ten Islamic banks were included in the QBL scoring and ranking exercisesPractical implicationsIslamic banks can improve their sustainability by increasing green financing and reaching out to rural areas and disadvantaged populations. In countries with Islamic banking systems, regulators can support this through training, guidance and incentives.Originality/valuePioneering exploration of TBL from maqasid al-shari'ah perspective. First, we develop a QBL index to assess the sustainability of Islamic banks in line with actual stakeholder expectations.
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Del Casale, Antonio, Stefano Ferracuti, Alessio Mosca, Leda Marina Pomes, Federica Fiaschè, Luca Bonanni, Marina Borro, Giovanna Gentile, Paolo Martelletti, and Maurizio Simmaco. "Multiple Chemical Sensitivity Syndrome: A Principal Component Analysis of Symptoms." International Journal of Environmental Research and Public Health 17, no. 18 (September 9, 2020): 6551. http://dx.doi.org/10.3390/ijerph17186551.

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Multiple Chemical Sensitivity (MCS) is a chronic and/or recurrent condition with somatic, cognitive, and affective symptoms following a contact with chemical agents whose concentrations do not correlate with toxicity in the general population. Its prevalence is not well defined; it mainly affects women between 40 and 50 years, without variations in ethnicity, education and economic status. We aimed to assess the core symptoms of this illness in a sample of Italian patients. Two physicians investigated different symptoms with a checklist compilation in 129 patients with MCS (117 women). We conducted a categorical Principal Component Analysis (CATPCA) with Varimax rotation on the checklist dataset. A typical triad was documented: hyperosmia, asthenia, and dyspnoea were the most common symptoms. Patients also frequently showed cough and headache. The CATPCA showed seven main factors: 1, neurocognitive symptoms; 2, physical (objective) symptoms; 3, gastrointestinal symptoms; 4, dermatological symptoms; 5, anxiety-depressive symptoms; 6, respiratory symptoms; 7, hyperosmia and asthenia. Patients showed higher mean prevalence of factors 7 (89.9%), 6 (71.7%), and 1 (62.13%). In conclusion, MCS patients frequently manifest hyperosmia, asthenia, and dyspnoea, which are often concomitant with other respiratory and neurocognitive symptoms. Considering the clinical association that is often made with anxiety, more studies are necessary on the psychosomatic aspects of this syndrome. Further analytical epidemiological studies are needed to support the formulation of aetiological hypotheses of MCS.
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Navas González, Francisco, Jordi Jordana Vidal, Gabriela Pizarro Inostroza, Ander Arando Arbulu, and Juan Delgado Bermejo. "Can Donkey Behavior and Cognition Be Used to Trace Back, Explain, or Forecast Moon Cycle and Weather Events?" Animals 8, no. 11 (November 19, 2018): 215. http://dx.doi.org/10.3390/ani8110215.

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Donkeys have been reported to be highly sensitive to environmental changes. Their 8900–8400-year-old evolution process made them interact with diverse environmental situations that were very distant from their harsh origins. These changing situations not only affect donkeys’ short-term behavior but may also determine their long-term cognitive skills from birth. Thus, animal behavior becomes a useful tool to obtain past, present or predict information from the environmental situation of a particular area. We performed an operant conditioning test on 300 donkeys to assess their response type, mood, response intensity, and learning capabilities, while we simultaneously registered 14 categorical environmental factors. We quantified the effect power of such environmental factors on donkey behavior and cognition. We used principal component analysis (CATPCA) to reduce the number of factors affecting each behavioral variable and built categorical regression (CATREG) equations to model for the effects of potential factor combinations. Effect power ranged from 7.9% for the birth season on learning (p < 0.05) to 38.8% for birth moon phase on mood (p < 0.001). CATPCA suggests the percentage of variance explained by a four-dimension-model (comprising the dimensions of response type, mood, response intensity and learning capabilities), is 75.9%. CATREG suggests environmental predictors explain 28.8% of the variability of response type, 37.0% of mood, and 37.5% of response intensity, and learning capabilities.
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VOZALIS, MANOLIS G., ANGELOS I. MARKOS, and KONSTANTINOS G. MARGARITIS. "AN OPTIMAL SCALING FRAMEWORK FOR COLLABORATIVE FILTERING RECOMMENDATION SYSTEMS." International Journal on Artificial Intelligence Tools 21, no. 06 (December 2012): 1250033. http://dx.doi.org/10.1142/s0218213012500339.

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Collaborative Filtering (CF) is a popular technique employed by Recommender Systems, a term used to describe intelligent methods that generate personalized recommendations. Some of the most efficient approaches to CF are based on latent factor models and nearest neighbor methods, and have received considerable attention in recent literature. Latent factor models can tackle some fundamental challenges of CF, such as data sparsity and scalability. In this work, we present an optimal scaling framework to address these problems using Categorical Principal Component Analysis (CatPCA) for the low-rank approximation of the user-item ratings matrix, followed by a neighborhood formation step. CatPCA is a versatile technique that utilizes an optimal scaling process where original data are transformed so that their overall variance is maximized. We considered both smooth and non-smooth transformations for the observed variables (items), such as numeric, (spline) ordinal, (spline) nominal and multiple nominal. The method was extended to handle missing data and incorporate differential weighting for items. Experiments were executed on three data sets of different sparsity and size, MovieLens 100k, 1M and Jester, aiming to evaluate the aforementioned options in terms of accuracy. A combined approach with a multiple nominal transformation and a "passive" missing data strategy clearly outperformed the other tested options for all three data sets. The results are comparable with those reported for single methods in the CF literature.
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Cebrián-Cifuentes, Sara, Gonzalo Almerich, Jesús Suárez-Rodríguez, and Francesc Pedró. "Incidencia de factores personales y contextuales sobre el uso de los recursos tecnológicos por el alumnado en América Latina." education policy analysis archives 29 (January 18, 2021): 6. http://dx.doi.org/10.14507/epaa.29.5127.

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El uso de las tecnologías de la información y de la comunicación (TIC) por parte de alumnado refleja si el proceso de integración es apropiado. No obstante, la tipología de uso de las TIC en el alumnado no se ha establecido de forma empírica en función de su uso en casa y el centro educativo. Así, el propósito del artículo es determinar la estructura del uso de las TIC por parte del alumnado, junto con la influencia de factores personales y contextuales. Se ha empleado un diseño correlacional, siendo la muestra el alumnado de sexto curso de América Latina que ha respondido al cuestionario sobre uso de las TIC en el Tercer Estudio Regional Comparativo y Explicativo (TERCE). El análisis de datos realizado es estadísticos descriptivos, Análisis Multivariado de Varianza (MANOVA) y el análisis de Componentes Principales Categórico (CATPCA). Los resultados arrojados a través de los estadísticos descriptivos, muestran como el alumnado realiza un mayor uso de los recursos tecnológicos en el ámbito del tiempo libre que en el académico. Se ha encontrado, mediante un análisis de Componentes Principales Categorial (CATPCA), que el uso del alumnado se estructura en tres planos: personal, académico no escolar y académico escolar. Además, los resultados obtenidos del MANOVA indican que los factores personales y contextuales influyen en el uso de las TIC, esencialmente la disponibilidad de dispositivos tecnológicos y la conexión a Internet. A la luz de los resultados se recomienda implementar programas que favorezcan el uso académico no escolar de las TIC por parte del alumnado.
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47

McClard, Cynthia K., Rui Wang, Victoria Windham, Jose Munoz, Samuel Gomez, Sagit Fried, Namrata Saroj, Carl Regillo, Charles Clifton Wykoff, and Adriana M. Strutt. "Questionnaire to Assess Life Impact of Treatment by Intravitreal Injections (QUALITII): Development of a patient-reported measure to assess treatment burden of repeat intravitreal injections." BMJ Open Ophthalmology 6, no. 1 (April 2021): e000669. http://dx.doi.org/10.1136/bmjophth-2020-000669.

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ObjectiveTo understand patient burden of treatment of repeated intravitreal injections (IVI) in the management of exudative retinal diseases.Methods and analysisParticipants were sampled from a large urban retina specialty practice in Houston, Texas, USA, based on history of ongoing receipt of IVI. The 50-item Questionnaire to Assess Life Impact of Treatment by Intravitreal Injections questionnaire was developed to evaluate the patient experience including discomfort, anxiety, inconvenience and satisfaction. Categorial principal components analysis (CATPCA) was performed to assess construct validity and internal consistency. A subset of these items was used to establish a measure of total treatment burden, referred to as the IVI Treatment Burden Score (TBS).Results142 patients participated in this study. CATPCA analysis revealed five dimensions of patient burden: disruption of normal routine or capacity, anxiety, frequency of visits, chronicity of disease and perceived treatment value or satisfaction. Together, these dimensions accounted for 67% of variance explained. Cronbach’s alpha was 0.97. The most frequently cited cause of discomfort was the feeling after anaesthetic wore off. The most common source of anxiety was fear of injection and associated discomfort or pain. Regarding inconvenience, patients reported temporary postinjection debilitation, requiring an average of 8 hours for recovery per treatment. The most frequently identified sources of satisfaction were confidence in the provider or treatment and interactions with staff.ConclusionsUnderstanding and quantifying the patient burden associated with repeated IVI for exudative retinal diseases can reveal opportunities to improve delivery methods. The TBS could serve to inform strategies to maximise treatment adherence and optimise patient experiences.
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48

Krug, Isabel, Janet Treasure, Marija Anderluh, Laura Bellodi, Elena Cellini, David Collier, Milena di Bernardo, et al. "Associations of individual and family eating patterns during childhood and early adolescence: a multicentre European study of associated eating disorder factors." British Journal of Nutrition 101, no. 6 (August 28, 2008): 909–18. http://dx.doi.org/10.1017/s0007114508047752.

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The objective of this study was to examine whether there is an association between individual and family eating patterns during childhood and early adolescence and the likelihood of developing a subsequent eating disorder (ED). A total of 1664 participants took part in the study. The ED cases (n 879) were referred for assessment and treatment to specialized ED units in five different European countries and were compared to a control group of healthy individuals (n 785). Participants completed the Early Eating Environmental Subscale of the Cross-Cultural (Environmental) Questionnaire, a retrospective measure, which has been developed as part of a European multicentre trial in order to detect dimensions associated with ED in different countries. In the control group, also the General Health Questionnaire-28 (GHQ-28), the semi-structured clinical interview (SCID-I) and the Eating Attitudes Test (EAT-26) were used. Five individually Categorical Principal Components Analysis (CatPCA) procedures were adjusted, one for each theoretically expected factor. Logistic regression analyses indicated that the domains with the strongest effects from the CatPCA scores in the total sample were: food used as individualization, and control and rules about food. On the other hand, healthy eating was negatively related to a subsequent ED. When differences between countries were assessed, results indicated that the pattern of associated ED factors did vary between countries. There was very little difference in early eating behaviour on the subtypes of ED. These findings suggest that the fragmentation of meals within the family and an excessive importance given to food by the individual and the family are linked to the later development of an ED.
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Krefis, Anne Caroline, Jana Fischereit, Peter Hoffmann, Hans Pinnschmidt, Christina Sorbe, Matthias Augustin, and Jobst Augustin. "Temporal analysis of determinants for respiratory emergency department visits in a large German hospital." BMJ Open Respiratory Research 5, no. 1 (November 2018): e000338. http://dx.doi.org/10.1136/bmjresp-2018-000338.

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IntroductionAssociations between air pollutants, meteorological conditions and respiratory diseases have been extensively shown. The aim of this study was to investigate associations between daily meteorological data, data on air pollution and emergency department (ED) visits depending on the day of the week, season and year (study period from 2013 to 2015).MethodsHighly correlated environmental data entered a categorical principal components analysis (CATPCA). We analysed cross-correlation functions between the time series of the respective daily environmental factors and daily ED visits. Time lags with peak correlations of environmental variables obtained by the CATPCA on ED visits together with day of the week, year, running day (linear, quadratic and cubic), season and interaction terms entered the univariate analysis of variance (UNIANOVA) model.ResultsThe analyses demonstrated main effects on ED visits for the day of the week with highest admission rates on Mondays (B=10.69; ƞ2=0.333; p<0.001). A significant time trend could be observed showing increasing numbers of ED visits per each year (p<0.001). The variable ‘running day’ (linear, quadratic and cubic) indicated a significant non-linear effect over time. The variable season showed significant results with winter, spring and summer recording fewer ED visits compared with the reference season autumn. Environmental variables showed no direct associations with respiratory ED visits.DiscussionED visits were significantly associated with temporal variables. Our data did not show direct associations between environmental variables and ED visits.In times of rapid urbanisation, increases in respiratory diseases, temperature and air pollution, our analyses can help focus future studies and enhance strategies to reduce increasing numbers of respiratory diseases and ED visits. Because the potential costs of medical care in hospitals can be high compared with physicians, public health recommendations for reducing the increasing ED visits should be promoted and evaluated.
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IRINA-EUGENIA, IAMANDI, CONSTANTIN LAURA-GABRIELA, MUNTEANU SEBASTIAN MADALIN, and CERNAT-GRUICI BOGDAN. "Profiling the Sustainability of Stock Exchanges at Global Level through an Optimal Scaling Process by Applying CATPCA." ECONOMIC COMPUTATION AND ECONOMIC CYBERNETICS STUDIES AND RESEARCH 54, no. 3/2020 (September 18, 2020): 297–313. http://dx.doi.org/10.24818/18423264/54.3.20.18.

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