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Since the beginning of the COVID-19 pandemic, many works have been published proposing solutions to the problems that arose in this scenario. In this vein, one of the topics that attracted the most attention is the development of computer-based strategies to detect COVID-19 from thoracic medical imaging, such as chest X-ray (CXR) and computerized tomography scan (CT scan). By searching for works already published on this theme, we can easily find thousands of them. This is partly explained by the fact that the most severe worldwide pandemic emerged amid the technological advances recently achieved, and also considering the technical facilities to deal with the large amount of data produced in this context. Even though several of these works describe important advances, we cannot overlook the fact that others only use well-known methods and techniques without a more relevant and critical contribution. Hence, differentiating the works with the most relevant contributions is not a trivial task. The number of citations obtained by a paper is probably the most straightforward and intuitive way to verify its impact on the research community. Aiming to help researchers in this scenario, we present a review of the top-100 most cited papers in this field of investigation according to the Google Scholar search engine. We evaluate the distribution of the top-100 papers taking into account some important aspects, such as the type of medical imaging explored, learning settings, segmentation strategy, explainable artificial intelligence (XAI), and finally, the dataset and code availability. [ABSTRACT FROM AUTHOR]

We estimate the orientation of wood fibers in porous networks like paper, paperboard or fiberboard by computing digital thermal conductivity experiments on micro-computed tomography ( μ CT) images with artificial isotropic thermal conductivity parameters. The accuracy of mechanical and thermal constitutive models for porous wood fiber based materials crucially depends on knowing the wood fiber orientation. Unfortunately, due to the high porosity, the micro-heterogeneity of wood fibers, the high carbon content of organic materials and the unknown additives present in industrial paper, μ CT-scans often exhibit low contrast and strong artifacts. Conventional image processing approaches encounter difficulties, as they rely upon convex fiber cross sections. We propose a solution by circumventing the segmentation of single wood fibers in μ CT images, by performing thermal conductivity simulations on binarized wood fiber structures, where an artificial isotropic thermal conductivity is associated to the fibers and the pore space is considered as isolating. The local and global temperature fluxes are assembled into a fiber orientation tensor. This method overcomes the limitations of the mentioned local image processing approaches, as individual fibers need not be resolved and convergence for increasing resolution is a consequence of abstract mathematical theory. We use our novel method to analyze large three-dimensional μ CT-scans and a synchrotron scan of a paperboard sample, serving as the starting point of an accurate micromechanical modeling of the effective anisotropic mechanical behavior of paper and paperboard. These results are crucial for calculating the mechanical strength of deep-drawn paperboard, which will be accomplished in a subsequent article. [ABSTRACT FROM AUTHOR]

Owing to the challenge of irregular morphology, the impact of compressed carbon fiber paper (CFP) on fuel cell performance and durability is intricate. As a carbon-carbon composite, the internal contact state of CFP directly determines its mechanical and physical properties. In this paper, fiber distribution and intersection of uncompressed CFP are achieved by X-ray computed tomography. Then we established an analytical model of bulk resistance based on the electron transfer path and provided a function to describe the internal contact state with strain. The results imply that the increasing number of electron paths and the variation of the contact state are the main factors for the decrease in bulk resistance under compression. The turning points in the contact state curve divide the range of pressure into fiber contact, elastic-plastic deformation and fiber fracture region, which can be used to assess the mechanical properties of CFP and determine the optimal pressure for fuel cell assembly. [Display omitted] • Fiber distribution and intersection of uncompressed CFP is given. • The effect of contact resistance between fibers on bulk resistance is evaluated. • The structural information to electric and mechanical properties is connected. [ABSTRACT FROM AUTHOR]

We admit, however, that fracture mechanical principles and rock physics elements behind rock fracturing and fault activation may be similar, and that the joint discussion of fracturing and faulting, therefore, has a long tradition in the rock mechanics and rock engineering community. 1 Participants of the '13th EURO-Conference on Rock Physics and Geomechanics - The Guéguen Conference' during the social event at the Winzerberg Potsdam This special issue consists of 19 scientific papers which are based on these conference contributions and all of which address different important aspects relevant to the variety of industrial applications outlined above. This special issue is dedicated to our dear colleague and friend Prof. Ove Stephansson, who was not only one of Sweden's most influential geologists, but also an enthusiastic supporter of the 13th EURO-Conference on Rock Physics and Geomechanics. Special Issue on Rock Fracturing and Fault Activation: Experiments and Models: Selected Papers Presented at the 13th EURO-Conference on Rock Physics and Geomechanics - The Guéguen Conference Held on 2-6 September 2019 in Potsdam, Germany. [Extracted from the article]

Defects, such as debonding and foreign matters in transformer insulation paperboard, lead to local field strength concentration, thereby seriously affecting the safe operation of equipment. At present, industrial X-ray computed tomography scanning technology is mostly used to detect such defects. However, the equipment is expensive, the operation is complicated, and radiation hazard exists. In this study, terahertz time domain spectroscopy is introduced to explore the nondestructive testing method of oil-paper insulation defects. Three typical insulation paperboard defects of interface debonding, metal foreign matter mixing, and local carbonization traces were taken as the research objects. An artificial defect model is prepared. The time and frequency domain waveform characteristics of terahertz pulse wave propagating in the defect model are tested and analyzed. The results show that when the thickness of insulation paperboard covering is less than 5 mm, based on the amplitude and delay characteristics of terahertz time-domain signal, the location and size of typical internal defects can be accurately obtained, and time spectrum imaging can be realized. This study proves theoretically and experimentally the feasibility of noncontact and nondestructive testing for the internal defects of insulation paperboard by using terahertz technology. [ABSTRACT FROM AUTHOR]

In daily clinical practice, clinicians integrate available data to ascertain the diagnostic and prognostic probability of a disease or clinical outcome for their patients. For patients with suspected or known cardiovascular disease, several anatomical and functional imaging techniques are commonly performed to aid this endeavor, including coronary computed tomography angiography (CCTA) and nuclear cardiology imaging. Continuous improvement in positron emission tomography (PET), single-photon emission computed tomography (SPECT), and CT hardware and software has resulted in improved diagnostic performance and wide implementation of these imaging techniques in daily clinical practice. However, the human ability to interpret, quantify, and integrate these data sets is limited. The identification of novel markers and application of machine learning (ML) algorithms, including deep learning (DL) to cardiovascular imaging techniques will further improve diagnosis and prognostication for patients with cardiovascular diseases. The goal of this position paper of the European Association of Nuclear Medicine (EANM) and the European Association of Cardiovascular Imaging (EACVI) is to provide an overview of the general concepts behind modern machine learning-based artificial intelligence, highlights currently prefered methods, practices, and computational models, and proposes new strategies to support the clinical application of ML in the field of cardiovascular imaging using nuclear cardiology (hybrid) and CT techniques. [ABSTRACT FROM AUTHOR]

Summary This Review provides an updated approach to the diagnosis of idiopathic pulmonary fibrosis (IPF), based on a systematic search of the medical literature and the expert opinion of members of the Fleischner Society. A checklist is provided for the clinical evaluation of patients with suspected usual interstitial pneumonia (UIP). The role of CT is expanded to permit diagnosis of IPF without surgical lung biopsy in select cases when CT shows a probable UIP pattern. Additional investigations, including surgical lung biopsy, should be considered in patients with either clinical or CT findings that are indeterminate for IPF. A multidisciplinary approach is particularly important when deciding to perform additional diagnostic assessments, integrating biopsy results with clinical and CT features, and establishing a working diagnosis of IPF if lung tissue is not available. A working diagnosis of IPF should be reviewed at regular intervals since the diagnosis might change. Criteria are presented to establish confident and working diagnoses of IPF. [ABSTRACT FROM AUTHOR]

The article announces the 10th International Symposium on Digital Industrial Radiology and Computed Tomography (DIR 2025), hosted by COFREND, CEA List, and DGZfP, focusing on promoting knowledge exchange and advancements in digital industrial radiology and computed tomography. Scientists, users, equipment suppliers, and academic and industrial participants interested in non-destructive testing (NDT)/non-destructive evaluation (NDE) applications are encouraged to attend.

Objectives: To develop and evaluate methods for assembling radiopaque printed paper sheets to realistic patient phantoms for CT dose and image quality testing.Methods: CT images of two patients were radiopaque printed with aqueous potassium iodide solution (0.6 g/ml) on paper. Two methods were developed for assembling the paper sheets to head and neck phantoms. (1) Printed sheets were fed to a paper-based 3D printer along with corresponding 3D printable STL files. (2) Paper stacks of 5-mm thickness were glued with toner, cut to the patient shape and assembled to a phantom. In a sample application study, both phantoms were examined with five different tube current settings. Images were reconstructed using filtered-back projection (FBP) and iterative reconstruction (AIDR 3D) with three strength levels. Dose length product (DLP), signal-to-noise ratios (SNR) and contrast-to-noise ratios (CNRs) were analysed. Data were analysed using 2-way analysis of variance (ANOVA).Results: Both methods achieved anthropomorphic phantoms with detailed patient anatomy. The 3D printer yielded a precise reproduction of the external patient shape, but caused visible glue artefacts. Gluing with toner avoided these artefacts and yielded more flexibility with regard to phantom size. In the sample application study, non-inferior SNR and CNR and up to 83.7% lower DLP were achieved on the phantoms with AIDR 3D compared with FBP.Conclusions: Two methods for assembling radiopaque printed paper sheets to phantoms of individual patients are presented. The sample application demonstrates potential for simulation of patient imaging and systematic CT dose and image quality assessment.Key Points: • Two methods were developed to create realistic CT phantoms of individual patients from radiopaque printed paper sheets. • Analysis of five tube current and four reconstruction settings on two radiopaque 3D printed patient phantoms yielded non-inferior SNR and CNR and up to 83.7% lower dose with iterative reconstruction in comparison with filtered back projection. • Radiopaque 3D printed phantoms can simulate patients and allow systematic analysis of CT dose and image quality parameters. [ABSTRACT FROM AUTHOR]

With the advancement of IoT(Internet of Things), image processing is being studied in various fields. Salt and pepper(S&P) noise in image acquisition devices, such as CT(Computed Tomography), MRI(Magnetic Resonance Imaging), X-ray, and scanning equipment, may develop due to environmental and physical factors, thereby distorting the original image. Numerous studies have been conducted to remove S&P noise, but existing filters have shown significantly insufficient restoration of high-density noise, low-light, and patterned images. Therefore, this paper proposes a filter high-density and low-light noise environments and preserve the patterns properties appearing in the images. In the proposed algorithm, we design local masks transformed for high-density noise and low-light images and defined the patterns represented in the images by determining and grouping similar pixels. Different filters are applied according to the pattern of similar pixel group to preserve the geometry based on its position in the input image. [ABSTRACT FROM AUTHOR]

Objectives: Posterior tibial slope (PTS) is a known anatomical factor in the biomechanical function of the anterior cruciate ligament. However, when PTS is typically measured on a lateral radiograph, this does not consider potential differences between the lateral and medial tibial plateau. The difference between medial posterior tibial slope (MPTS) and lateral posterior tibial slope (LPTS) in a knee is largely unknown. Generally, computed tomography (CT) is the gold standard for 3-dimensional osseus imaging but very few studies to date have attempted to quantify the medial and lateral PTS in the same knee using CT. Clinically, it is debated whether an elevated MPTS or the LPTS is critical for anterior cruciate ligament injury and reinjury. The objective of this study was to quantify the variation in the difference between MPTS and LPTS using full tibial CT scans. Methods: At our institution, CT-assisted preoperative planning is frequently used for osteotomies. Ninety-seven patients with clinically acquired CT scans went through the preoperative planning process (Bodycad, Quebec City, Canada) from Jan 2016 to Nov 2022. This includes patients undergoing coronal, sagittal or biplanar high tibial and distal femoral osteotomies. This process is semi-automated meaning that the user can intervene with the measurements and adjust the initial landmarks and best-fit. Distally, the software will find the center of the tibiotalar joint to provide a point for the tibial axis. The user may adjust that landmark if needed. To measure the tibial slope, the software finds the best fit tibial plateau in 3D and determines the slope angle medially and laterally. The software measures the MPTS and LPTS independently. The slope measurements were compiled and quantitatively analyzed including mean, median, range as well as the difference between the MPTS and LPTS. Patients were defined to have undergone a sagittal or coronal correction if there was more than 2 degrees of change in the sagittal plane or more than 5% change in the coronal plane weight bearing line. Patients were defined as having a biplanar correction when both conditions were met. The slopes were analyzed with respect to sex and laterality. Additionally, patients undergoing an osteotomy in conjunction with an ACL reconstruction (either single or two-staged) were compared to the other patients. Results: There are differences in the MPTS and LPTS within the same knee. When analyzing the whole group, the average absolute difference is 2.76⁰ with a standard deviation of 2.49. As shown in Table 1, 40% of knees had greater than a 2.5⁰ difference in MPTS and LPTS, 19% of knees had greater than a 5⁰ difference in MPTS and LPTS, 5% of knees had greater than a 7.5⁰ difference in MPTS and LPTS and 2% of knees had greater than a 10⁰ difference in MPTS and LPTS. The magnitude of the LPTS is greater than the MPTS 52% of the time. There is no significant difference in the average, standard deviation, mean or the 10th, 25th, 75th and 90th percentiles of the MPTS and LPTS as shown in Table 2. One hundred percent of the sagittal corrections and 84% of the biplanar corrections also underwent an ACL reconstruction in addition to an osteotomy. Characteristics of these groups of patients are shown in table 3. The sagittal and coronal osteotomy patients have a higher MPTS and LPTS than the patients undergoing a coronal osteotomy. Conclusions: The most important finding in this study is that the medial and lateral PTS can be very different within the same knee. There can be up to 11.62-degree difference in this population. Sixteen out of 97 patients had a difference of more than 5⁰ with 2 patients having a difference of greater than 10⁰. The data presented here has uncovered a description of the medial and lateral posterior tibial slope anatomy that was not evident with conventional lateral knee x-rays previously. We do not know the clinical significance of a large difference in the medial and lateral PTS and it brings forth an interesting set of clinical questions. 1) Which posterior tibial slope, medial or lateral, is most important for knee biomechanics, specifically regarding ACL stresses and function? 2) When performing a slope correcting osteotomy, is it the medial, lateral or average slope that should be the target for correction? 3) Should an intercondylar correction which only modifies one slope be considered? Further clinical studies should focus on investigating the relationship of differential PTS to native knee biomechanics as well as its implication for corrective osteotomy procedures and ACL reconstruction. [ABSTRACT FROM AUTHOR]

Summary CT is increasingly being used to stage and quantify the extent of diffuse lung diseases both in clinical practice and in treatment trials. The role of CT in the assessment of patients entering treatment trials has greatly expanded as clinical researchers and pharmaceutical companies have focused their efforts on developing safe and effective drugs for interstitial lung diseases, particularly for idiopathic pulmonary fibrosis. These efforts have culminated in the simultaneous approval by the US Food and Drug Administration of two new drugs for the treatment of idiopathic pulmonary fibrosis. CT features are a key part of the inclusion criteria in many drug trials and CT is now being used to refine the type of patients enrolled. Interest in the potential use of serial CT as an effectiveness endpoint is increasing. For chronic progressive diseases, mortality may not be a feasible endpoint and many surrogate markers have been explored, ranging from pulmonary function decline to biomarkers. However, these surrogate markers are not entirely reliable and combinations of endpoints, including change in disease extent on CT, are being investigated. Methods to assess disease severity with CT range from simple visual estimates to sophisticated quantification by use of software. In this Position Paper, which cannot be regarded as a comprehensive set of guidelines in view of present knowledge, we examine the uses of serial CT in clinical practice and in drug trials and draw attention to uncertainties and challenges for future research. [ABSTRACT FROM AUTHOR]

With more than 23 million infections and more than 814,000 deaths worldwide, the coronavirus disease-2019 (COVID-19) pandemic is still far from over. Several classes of drugs including antivirals, antiretrovirals, anti-inflammatory, immunomodulatory, and antibiotics have been tried with varying levels of success. Still, there is lack of any specific therapy to deal with this infection. Although less than 30% of these patients require intensive care unit admission, morbidity and mortality in this subgroup of patients remain high. Hence, it becomes imperative to have general principles to guide intensivists managing these patients. However, as the literature emerges, these recommendations may change and hence, frequent updates may be required. [ABSTRACT FROM AUTHOR]

By analyzing the three-dimensional digital model of a real carbon paper gas diffusion layer (GDL) reconstructed by X-ray computed tomography (CT), it was found that fibers are not distributed at any angle but within a certain range. The fiber orientation can be represented by fiber pitch (i.e., the angle between a single fiber and the in-plane direction). The effect of fiber orientation on stochastic reconstruction and transport properties (permeability) was investigated in this paper to find which fiber pitch range can achieve a better GDL on fluid flow. First, the actual fiber pitch was measured by analyzing SGL-24BA images obtained by X-ray CT. Also, seven different ranges of fiber pitch were randomly chosen to reconstruct GDL. Then, the permeability of these digital models was calculated using the Lattice Bolzmann Method (LBM) and discussed to obtain the fiber pitch range of the optimal permeability. The results show that the mean fiber pitch of SGL-24BA is 2.40° and the individual values are all less than 6°, also, the permeability of the through-plane direction increases gradually as the range of fiber pitch increases, which can be used for the structural design of carbon paper GDL. [ABSTRACT FROM AUTHOR]

This paper presents the use of X-ray computed tomography and X-ray fluorescence in the analysis and expert research of the seventeenth century printed book "Eukhologīon albo Molitoslov, ili Trebnik" from Kiev. The main purpose of the survey was to confirm whether the book binding is original or whether it is a rebinding, and whether there are any fragments of the hidden older texts. Commonly used radiography is usually not able to provide sufficient information for these purposes. On the other hand, computed tomography allows a detailed and three-dimensional documentation of the bookbinding technology and the structure of the materials used, including the wooden boards. It will be presented that all elements of the weave are clearly visible, making it possible to show that there are no internal defects in the stitching and materials. It has also been convincingly shown that there are no fragments or layers of older texts in the binding, so no further invasive intervention will be necessary regarding this aspect. The paper also demonstrates the possibility of reading the text in a closed book utilising X-ray computed tomography data; this option may be advantageous for massively damaged manuscripts. It will also be shown, that thanks to detailed tomographic imaging of the wood structure of the boards, a dendrochronological survey can be successfully carried out without invasive intervention into their outer layers. From the CT data it was also found that the pigments of the letters have significantly different densities. Therefore, as part of the survey, elemental analysis of the writing was also carried out using a portable X-ray fluorescence spectrometer to confirm and clarify this finding. [ABSTRACT FROM AUTHOR]

This paper proposes applying a novel deep‐learning model, TBDLNet, to recognize CT images to classify multidrug‐resistant and drug‐sensitive tuberculosis automatically. The pre‐trained ResNet50 is selected to extract features. Three randomized neural networks are used to alleviate the overfitting problem. The ensemble of three RNNs is applied to boost the robustness via majority voting. The proposed model is evaluated by five‐fold cross‐validation. Five indexes are selected in this paper, which are accuracy, sensitivity, precision, F1‐score, and specificity. The TBDLNet achieves 0.9822 accuracy, 0.9815 specificity, 0.9823 precision, 0.9829 sensitivity, and 0.9826 F1‐score, respectively. The TBDLNet is suitable for classifying multidrug‐resistant tuberculosis and drug‐sensitive tuberculosis. It can detect multidrug‐resistant pulmonary tuberculosis as early as possible, which helps to adjust the treatment plan in time and improve the treatment effect. [ABSTRACT FROM AUTHOR]

The article calls for the submission of papers in the area of digital industrial radiology and computed tomography (CT) for the International Symposium on Digital Industrial Radiology and Computed Tomography to be held from July 2-4, 2019 in Fürth, Germany.

The article discusses the diagnosis and investigation of patients with mantle cell lymphoma (MCL. Topics covered include the latest information on molecular pathology, the use of positron emission tomography/computed tomography (PET/CT) scanning in staging and response assessment, and biological prognostic factors of MCL.