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Maize is susceptible to hypoxia stress in soils with poor aeration, but the macropores have the potential to improve soil aeration. We studied the impact of artificial macropores on maize performance under poor aeration. Three levels of air-filled porosity (5%, 10% and 15%) were established, and soil columns with (28 vertical artificial macropores with 0.5 mm diameter) or without macropores were created for each level of air-filled porosity with a bulk density of 1.3 g cm-3. Root–macropore interactions were visualized using CT scanning (41 μm in resolution). Our results showed that root length density significantly increased by 114%, as air-filled porosity increased from 5% to 15%. However, when artificial macropores were present, an increase in air-filled porosity had no significant effect on root length density. The treatment of 5% air-filled porosity with macropores significantly increased root length density and root biomass by 108% and 65%, respectively, relative to the treatment of 5% air-filled porosity without macropores, whereas there was no significant difference in root growth between the treatments of 15% air-filled porosity with and without macropores. Compared to the treatment of 5% air-filled porosity with macropores, there was a significant reduction of 49% in the number of macropores colonized by roots under the treatment of 15% air-filled porosity with macropores. Our results demonstrate that macropores provide preferential paths for the colonization of maize roots, thereby promoting root growth under poor aeration. Creating macropores with bio-tillage can serve as a crucial strategy for enhancing crop performance in poorly aerated soils. [ABSTRACT FROM AUTHOR]

Due to the detrimental effects of moisture in the built environment, there is a continuous interest in non-destructive experimental techniques that quantify and/or localise moisture in materials. Most existing experimental techniques, however, typically focus on macroscopic moisture contents in samples rather than the microscopic distribution of water in the individual pores of building materials. For the latter, a popular method such as X-ray computed tomography is not readily applicable, due to the gap between its spatial resolution limit and the typical pore sizes of building materials. Nuclear magnetic resonance (NMR) relaxometry is capable of measuring water in pores of both the nanometer and micrometer scale and is therefore an interesting possibility. While most NMR research focusses on water-saturated materials or overall moisture contents, this study determines the size distributions of the water islands in unsaturated materials with NMR, and compares results to X-ray computed tomography (XCT) images and pore network model (PNM) simulations. Results on unsaturated materials show that NMR focusses on the biggest water islands (i.e. in capillary filled pores) and disregards the hydrogen nuclei in smaller water islands (i.e. stored in pore corners). NMR relaxometry is therefore only adept at providing very rough estimates of the size of water-filled pores, especially since post-processing of the NMR experiments to obtain these water island size distributions involves a lot of uncertainty. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the clinical significance and stage migration effect of radiological diameter-to-thickness (DT) ratio in HER2-positive resectable advanced gastric cancer (HER2-p RAGC). Methods: 369 HER2-p RAGC patients were retrospectively enrolled and information on clinical pathological characteristics, radiological DT ratio, and outcomes [i.e., overall survival (OS) and progression-free survival (PFS)] was collected. Pearson's Chi-square and Student's t-test were employed to compare baseline characteristics. Clinical outcomes were estimated using Kaplan–Meier analysis and Log-rank test. Univariate and multivariate Cox regression models were utilized to analyze independent prognostic factors. Results: HER2-p RAGC patients were stratified into two groups using a DT ratio cutoff value of 4.0 (p < 0.05). Patients with a DT ratio < 4.0 exhibited significantly longer OS (58.0 vs. 31.0 months) and PFS (43.0 vs. 24.0 months) than those with a DT ratio ≥ 4.0. DT ratio significantly predicted prognosis for N0 and II stage patients (p < 0.05). Patients with gastric body and antrum cancers demonstrated longer OS and PFS in the DT ratio < 4.0 group (p = 0.046, 0.017, 0.036 and 0.028). Multivariate Cox proportional hazard model identified age, pathological T category, pathological N category, pathological TNM category and DT ratio as independent prognostic factors. Notably, pStage II patients with a DT ratio ≥ 4.0 exhibited a similar prognosis to pStage III patients with a DT ratio < 4.0 (p = 0.418 for OS, 0.867 for PFS). Conclusion: Radiological DT ratio could evaluate the prognosis and detect higher malignant cases in HER2-p RAGC patients. Moreover, DT ratio might guide clinicians make postoperative strategies. Trial registration: Retrospectively registered. [ABSTRACT FROM AUTHOR]

Background: The aim of our current systematic dynamic phantom study was first, to optimize reconstruction parameters of coronary CTA (CCTA) acquired on photon counting CT (PCCT) for coronary artery calcium (CAC) scoring, and second, to assess the feasibility of calculating CAC scores from CCTA, in comparison to reference calcium scoring CT (CSCT) scans. Methods: In this phantom study, an artificial coronary artery was translated at velocities corresponding to 0, < 60, and 60–75 beats per minute (bpm) within an anthropomorphic phantom. The density of calcifications was 100 (very low), 200 (low), 400 (medium), and 800 (high) mgHA/cm3, respectively. CCTA was reconstructed with the following parameters: virtual non-iodine (VNI), with and without iterative reconstruction (QIR level 2, QIR off, respectively); kernels Qr36 and Qr44f; slice thickness/increment 3.0/1.5 mm and 0.4/0.2 mm. The agreement in risk group classification between CACCCTA and CACCSCT scoring was measured using Cohen weighted linear κ with 95% CI. Results: For CCTA reconstructed with 0.4 mm slice thickness, calcium detectability was perfect (100%). At < 60 bpm, CACCCTA of low, and medium density calcification was underestimated by 53%, and 15%, respectively. However, CACCCTA was not significantly different from CACCSCT of very low, and high-density calcifications. The best risk agreement was achieved when CCTA was reconstructed with QIR off, Qr44f, and 0.4 mm slice thickness (κ = 0.762, 95% CI 0.671–0.853). Conclusion: In this dynamic phantom study, the detection of calcifications with different densities was excellent with CCTA on PCCT using thin-slice VNI reconstruction. Agatston scores were underestimated compared to CSCT but agreement in risk classification was substantial. Clinical relevance statement: Photon counting CT may enable the implementation of coronary artery calcium scoring from coronary CTA in daily clinical practice. Key Points: Photon-counting CTA allows for excellent detectability of low-density calcifications at all heart rates. Coronary artery calcium scoring from coronary CTA acquired on photon counting CT is feasible, although improvement is needed. Adoption of the standard acquisition and reconstruction protocol for calcium scoring is needed for improved quantification of coronary artery calcium to fully employ the potential of photon counting CT. [ABSTRACT FROM AUTHOR]

Inspection of thick and low-density multilayer composite structures is of paramount importance. X-ray computed tomography (CT) and phased array ultrasonic testing (PAUT) are widely employed modalities for non-destructive testing (NDT) of these composites. Owing to low density of constituent materials typically utilised to construct composites and rich wave scattering within their structures, inspecting them using X-ray CT and PAUT does not always yield acceptable flaw detection results. On the other hand, microwave NDT techniques have shown to be particularly suitable for inspecting thick multilayer non-carbon-based composites. However, the relative performance of emerging microwave NDT techniques and the widely accepted X-ray CT and PAUT is yet to be established. This paper provides first-of-its-kind experimental comparison between microwave, X-ray CT, and PAUT on a comprehensive set of thick composite samples with different defect types. It is demonstrated herein that microwave NDT performed on par with X-ray CT in terms of defect detection capability (qualitatively and quantitatively), and in many cases outperformed PAUT. A detailed summary overviewing the performance, advantages and shortcomings of each method for particualr defect types is included which disseminates new knowledge to benefit practitioners and researchers alike. [ABSTRACT FROM AUTHOR]

An important aspect to consider in the evaluation of parts and assemblies by X-ray computed tomography (XCT) is the attenuation coefficient of the different materials involved, which are directly related to their density; depending on this coefficient, the X-ray penetration varies and, therefore, varies the contrast between different materials and with the background. This becomes more critical in those assemblies in which materials are characterized by a high difference in density, where the lighter material could be difficult to be characterised. In this paper, the effect of the presence of metals in the dimensional evaluation of polymeric geometries (having lower density than the metal parts) is studied, to evaluate the errors caused in dimensional measurements of different geometries and surface texture characterization. Based on a common geometry, four scenarios have been experimentally tested with variations of metal amount, in which macro geometries (precision spheres made by different polymers) and micro geometries (inclined ramps manufactured by fused deposition modelling (FDM)) have been characterised. Results show errors in the surface determination of the polymeric features directly related to the presence of metal: a high amount of steel makes significantly difficult to accurately determine the interface between background and material due to the noise and artifacts created, while aluminium has less influence on the irregularities of the features extracted. This effect is more evident for polymers with lower density due to the higher difference. Numerically, most affected parameters are those sensible to variations in surface determination, such as spheres' form error and ramps' maximum surface texture (Sz), while more solid features as spheres' diameters, distances and ramps' average surface texture (Sa and Sq) remain more stable. In conclusion and to sum up, it has been found that the quantity of metal present in assemblies made of polymeric and metallic materials is correlated with distortions in the dimensional evaluation of polymeric features by XCT. [ABSTRACT FROM AUTHOR]

Carbon fiber laminates are susceptible to impact damage due to the lack of fibers in the direction of impact. Often such damage can be difficult to find with visual assessment, prompting the need for detection via nondestructive testing techniques. This study quantifies the ultrasonically characterized impact damage diameters in 22 layered CFRP samples from 16 J, 18 J, 20 J, 22 J, and 24 J impact energies. These energies result in damage often defined as barely visible impact damage. This study utilizes x-ray computed tomography as a baseline to verify the results of the ultrasonic testing. Compression after impact test measurements are used in this study to find the ultimate compressive residual strength of the impacted carbon fiber laminates and to investigate the negative correlation between impact energy and residual mechanical properties of the damaged carbon fiber laminates. Many studies focus on the characterization of impact damage from various impact energies and setups via ultrasonic testing or, separately, the effect of the impact setups on the residual strength of the composite. This study strengthens the bridge between the barely visible impact damage quantified via ultrasonic testing and the residual compressive strength of the affected composite. Overall, this paper offers further insights into the relationship between internal damage size obtained using ultrasonic testing and correlates the characterized internal damage geometry to the resultant compressive strength reduction, providing a path for future studies in predictive modeling of the residual strength after impact. [ABSTRACT FROM AUTHOR]

ABSTRACT X‐ray computed tomography (XCT) is extremely useful for the non‐destructive analysis of additively manufactured (AM) components. AM components often show manufacturing defects such as lack‐of‐fusion (LoF), which are detrimental to the fatigue life of components. To better understand how cracks initiate and propagate from internal defects, we fabricated Ti‐6Al‐4V samples with an internal cavity using electron beam powder bed fusion. The samples were tested in high‐cycle and very high‐cycle fatigue regimes. XCT was used to locate crack initiation sites and to determine characteristic properties of cracks and defects with the aid of deep learning segmentation. LoF defects exposed to the outer surface of the samples after machining were found to be as detrimental to fatigue life as the internal artificial defects. This work can benefit industries that utilize the AM of high‐strength, lightweight alloys, in the design and manufacturing of components to improve part reliability and fatigue life. [ABSTRACT FROM AUTHOR]

Maize is susceptible to hypoxia stress in soils with poor aeration, but the macropores have the potential to improve soil aeration. We studied the impact of artificial macropores on maize performance under poor aeration. Three levels of air-filled porosity (5%, 10% and 15%) were established, and soil columns with (28 vertical artificial macropores with 0.5 mm diameter) or without macropores were created for each level of air-filled porosity with a bulk density of 1.3 g cm-3. Root-macropore interactions were visualized using CT scanning (41 mm in resolution). Our results showed that root length density significantly increased by 114%, as air-filled porosity increased from 5% to 15%. However, when artificial macropores were present, an increase in air-filled porosity had no significant effect on root length density. The treatment of 5% air-filled porosity with macropores significantly increased root length density and root biomass by 108% and 65%, respectively, relative to the treatment of 5% air-filled porosity without macropores, whereas there was no significant difference in root growth between the treatments of 15% air-filled porosity with and without macropores. Compared to the treatment of 5% air-filled porosity with macropores, there was a significant reduction of 49% in the number of macropores colonized by roots under the treatment of 15% air-filled porosity with macropores. Our results demonstrate that macropores provide preferential paths for the colonization of maize roots, thereby promoting root growth under poor aeration. Creating macropores with bio-tillage can serve as a crucial strategy for enhancing crop performance in poorly aerated soils. [ABSTRACT FROM AUTHOR]

X-Ray micro-computed tomography (XCT) is used to reveal the micro-structural changes of banana pseudostem nanocellulose bioplastic due to a biodegradation process initiated in a formulated composting media that allowed the growth of aerobic microflora. The bioplastic itself was made of nanocellulose, which was isolated from banana pseudostem using the 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidation method, and polyethylene glycol (PEG) as plasticiser. XCT provided insights into the 3D structural change of the bioplastic identifying the degradation process at two scales. The results showed that the local thickness and roughness of the bioplastic increased after degradation, while the density of the material decreased. Enlarged voids and tunnels were observed in the material after degradation. The formation of these tunnels is attributed to the popping of internal PEG-containing voids because of the generation of gases, which after forming may further accelerate biodegradation by microbial activity. [ABSTRACT FROM AUTHOR]

Background and Aims Root system architecture (RSA) plays a key role in plant adaptation to drought, because deep rooting enables better water uptake than shallow rooting under terminal drought. Understanding RSA during early plant development is essential for improving crop yields, because early drought can affect subsequent shoot growth. Herein, we demonstrate that root distribution in the topsoil significantly impacts shoot growth during the early stages of rice (Oryza sativa) development under drought, as assessed through three-dimensional image analysis. Methods We used 109 F12 recombinant inbred lines obtained from a cross between shallow-rooting lowland rice and deep-rooting upland rice, representing a population with diverse RSA. We applied a moderate drought during the early development of rice grown in a plant pot (25 cm in height) by stopping irrigation 14 days after sowing. Time-series RSA at 14, 21 and 28 days after sowing was visualized by X-ray computed tomography and, subsequently, compared between drought and well-watered conditions. After this analysis, we investigated drought-avoidant RSA further by testing 20 randomly selected recombinant inbred lines in drought conditions. Key Results We inferred the root location that most influences shoot growth using a hierarchical Bayes approach: the root segment depth that impacted shoot growth positively ranged between 1.7 and 3.4 cm in drought conditions and between 0.0 and 1.7 cm in well-watered conditions. Drought-avoidant recombinant inbred lines had a higher root density in the lower layers of the topsoil compared with the others. Conclusions Fine classification of soil layers using three-dimensional image analysis revealed that increasing root density in the lower layers of the topsoil, rather than in the subsoil, is advantageous for drought avoidance during the early growth stage of rice. [ABSTRACT FROM AUTHOR]

Background Aim Methods Results Conclusions Imaging techniques of analysis in undisturbed soil samples are powerful tools for understanding soil properties and functioning. Although micromorphological analysis has always been applied for studying soil genesis, the modern 3D X‐ray Computed Tomography (CT) approach is mostly used in soil physical studies related to soil functioning and ecological services.In this study, we interpret ancient soil formation of the Late Pleistocene pedosedimentary archive of the Tlalpan sequence in the State of Tlaxcala in Central Mexico, based on soil and sediment porosity distribution in 2D and 3D.In order to interpret ancient soil formation based on the porosity distribution, we applied both micromorphological (2D) and CT (3D) analyses in undisturbed samples of each horizon of the Tlalpan sequence.Our micromorphological observations have shown that pore space arrangement is unique for each soil horizon and that it is predetermined by the dominant pedogenetical processes and their succession, such as bioturbation, clay illuviation, and vertic shrinking/swelling. Most of the channels formed by biogenic agents (roots and mesofauna) subsequently underwent shape deformations and/or refilling. The “accommodating planes” type of voids resulted from the development of features of vertic paleosols that, in some cases, erased the past pedogenic pore space organization. Although biogenic turbation, compaction, and clay illuviation mostly affected the macro‐ and mesopores, shrinking/swelling processes affected macro‐ and mesoporosity distribution. The process that was only reflected at the microporosity level is hydroconsolidation.Despite the common idea that textural pores are more resistant to changes compared to meso‐ and macropores, most of soil formation processes registered in the Tlalpan sequence, including anthropogenic impact, were identified in macro‐ and mesopore space. Moreover, the changes that were registered in pore space transformation by 2D and 3D methods of analysis in undisturbed samples are crucial for identifying the sequence of formation processes and, therefore, for paleopedological interpretation. This study shows that the CT is a useful tool to access the soil formation, and pore space memory studied both in 3D and 2D is an important proxy for paleopedological research. [ABSTRACT FROM AUTHOR]

Objectives: To retrospectively evaluate the correlation between intradiscal gas and infection in patients percutaneously biopsied for suspected discitis-osteomyelitis. Materials and methods: We retrospectively reviewed all CT-guided discitis-osteomyelitis biopsies performed between 2002 and 2022. Two independent trained musculoskeletal radiologists evaluated for presence of gas on CT and/or MRI within 1 week of the biopsy. Disagreements were resolved by a third musculoskeletal radiologist. CT was considered the gold standard for the detection of intradiscal gas. Pathology, microbiology, and imaging and clinical follow-up were used as the gold standard for presence of infection. Interrater agreement on CT and MRI, sensitivity, and positive predictive value were calculated, using the presence of gas as an indicator (test positive) for "no infection." Results: There were 284 biopsies in 275 subjects (mean age 58 ± 1.0 (range 4–99) years; 101 (37%) females and 174 (63%) males). Of the biopsies, 12 (4%) were cervical, 80 (28%) were thoracic, 192 (68%) were lumbar, and 200 (70%) were considered true discitis-osteomyelitis based on pathology, imaging, and clinical follow-up. Interrater agreement was excellent for CT (kappa = 0.83) and poor for MRI (kappa = − 0.021). The presence of gas had a 94% specificity and 76% negative predictive value for the absence of infection. Conclusion: CT is the preferred method for detecting intradiscal gas. The presence of gas means that discitis-osteomyelitis is unlikely. If intradiscal gas is present in the setting of discitis-osteomyelitis, the gas bubbles tend to be smaller and fewer in number. [ABSTRACT FROM AUTHOR]

[Display omitted] • New powder reuse schema in powder bed fusion of polymers was demonstrated. • The characteristics of the recycled PA12 powder were investigated. • Recycled PA12 allowed to produce components with satisfactory properties. The laser-based powder bed fusion of polymers (PBF-LB/P) process often utilizes a blend of powders with varying degrees of degradation. Specifically, for polyamide 12, the traditional reuse schema involves mixing post-processed powder with virgin powder at a predetermined ratio before reintroducing it to the process. Given that only about 15% of the powder is utilized in part production, and powders are refreshed in equal proportions, there arises a challenge with the incremental accumulation of material across build cycles. To mitigate the consumption of fresh powder relative to the actual material usage, this study introduces the incorporation of recycled material into the PBF-LB/P process. This new powder reuse schema is presented for the first time, focusing on the laser sintering process. The characteristics of the recycled powder were evaluated through scanning electron microscopy, differential scanning calorimetry, X-ray diffraction, particle size distribution, and dynamic powder flowability assessments. The findings reveal that waste powders can be effectively reused in PBF-LB/P to produce components with satisfactory mechanical properties, porosity levels, dimensional accuracy, and surface quality. [ABSTRACT FROM AUTHOR]

Permeability is a crucial parameter in the exploration and development of oil and gas reservoirs, particularly in unconventional ones, where fractures significantly influence storage capacity and fluid flow. This study investigates the fracture permeability of granite reservoirs in the South China Sea, introducing an enhanced evaluation model for planar fracture permeability based on Darcy's law and Poiseuille's law. The model incorporates factors such as fracture heterogeneity, tortuosity, angle, and aperture to improve permeability assessments. Building on a single-fracture model, this research integrates mass transfer equations and trigonometric functions to assess intersecting fractures' permeability. Numerical simulations explore how tortuosity, angle, and aperture affect individual fracture permeability and the influence of relative positioning in intersecting fractures. The model makes key assumptions, including minimal consideration of horizontal stress and the assumption of unidirectional laminar flow in cross-fractures. Granite outcrop samples were systematically collected, followed by full-diameter core drilling. A range of planar models with varying fracture apertures were designed, and permeability measurements were conducted using the AU-TOSCAN-II multifunctional core scanner with a steady-state gas injection method. The results showed consistency between the improved model and experimental findings regarding the effects of fracture aperture and angle on permeability, confirming the model's accuracy in reflecting the fractures' influence on reservoir flow capacity. For intersecting fractures, a comparative analysis of core X-ray computed tomography (X-CT) scanning results and experimental outcomes highlighted discrepancies between actual permeability measurements and theoretical simulations based on tortuosity and aperture variations. Limitations exist, particularly for cross-fractures, where quantifying complexity is challenging, leading to potential discrepancies between simulation and experimental results. Further comparisons between core experiments and logging responses are necessary for model refinement. In response to the challenges associated with evaluating absolute permeability in fractured reservoirs, this study presents a novel theoretical assessment model that considers both single and intersecting fractures. The model's validity is demonstrated through actual core experiments, confirming the effectiveness of the single-fracture model while highlighting the need for further refinement of the dual-fracture model. The findings provide scientific support for the exploration and development of granite reservoirs in the South China Sea and establish a foundation for permeability predictions in other complex fractured reservoir systems, thereby advancing the field of fracture permeability assessment. [ABSTRACT FROM AUTHOR]

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Municipal solid waste incineration tailings were used as lightweight aggregate (MSWIT-LA) in the preparation of specified density concrete to study the effects on compressive strength, axial compressive strength, flexural strength, microhardness, total number of pores, pore area, and pore spacing. The results showed that the internal curing and morphological effects induced by an appropriate quantity of MSWIT-LA improved the compressive response of specified density concrete specimens, whereas an excessive quantity of MSWIT-LA significantly reduced their mechanical properties. An analysis of pore structure indicated that the addition of MSWIT-LA increased the total quantity of pores and promoted cement hydration, resulting in a denser microstructure than that of ordinary concrete. The results of a principal component analysis showed that the mechanical response of specified density concrete prepared with 25% MSWIT-LA was superior to that of an equivalent ordinary concrete. It was therefore concluded that MSWIT-LA can be feasibly applied to achieve excellent specified density concrete properties while utilising municipal solid waste incineration tailings to protect the environment and alleviate shortages of sand and gravel resources. [ABSTRACT FROM AUTHOR]

As the global lithium-ion batteries (LIBs) market continues to expand, the necessity for dependable and secure LIBs has reached an all-time high. However, the use of batteries is associated with a number of significant risks, including the potential for thermal runaway and explosions. The meticulous inspection of LIBs is not only essential for guaranteeing their quality and functionality, but also for ensuring their safety. This underscores the criticality of advanced inspection technologies. In contrast to traditional inspection technologies, industrial x-ray computed tomography (CT) scanning technology affords a non-destructive comprehensive, three-dimensional insight into the interior structure of a battery without the need for disassembly. It can make the inner LIBs structures visible through the housing and even batteries already installed in devices can be examined safely and accurately without being removed or opened. This capability is of critical importance for the identification of defects that could lead to battery failure or safety issues, and guide the optimization of LIBs with better safety and performance. This perspective review briefly summarize the comprehensive application of industrial CT in LIBs including battery materials, cells and modules. Finally, we further discuss the challenges and prospects of industrial CT for energy storage. [ABSTRACT FROM AUTHOR]

Investigating the spatial and size distributions of fracture structures formed by various external stresses in coal is essential for understanding fracture evolution and methane percolation behavior in coal reservoirs. To estimate the characteristics of microscale fractures in three-dimensional space, X-ray computed microtomography was used to establish digital reconstructed fracture models. Two algorithms that reflect topological features were applied to quantitatively characterize coal fractures. The results show that tectonic stress negatively affects the anisotropy of fractures, reducing the frequency of fractures that are approximately parallel or perpendicular to the main direction. A new fracture connectivity evaluation parameter, calculated by the integral average of the linear fitting curve between the coordination number and the corresponding average radius of many maximum spheres in the pore network model, is proposed. This method is more objective for evaluating fracture connectivity. The results indicate that with increasing tectonic action, fracture connectivity improves. Based on skeleton model data, we found a power-law relationship between the equivalent diameter of the fracture and the cumulative volume. Using this relationship and the capillary model assumption, we rederived expressions for total gas seepage flux and permeability applicable to fractures that do not conform to the tortuous fractal theory. Additionally, we discovered that the fracture aperture follows a log-normal distribution and derived an improved cube model's mathematical formula based on this. These findings are significant for revealing how different fracture structures affect gas seepage and provide a foundation for developing theoretical models to predict gas seepage in coal reservoirs. Article Highlights: A quantitative study of different coal fracture structures based on CT Comprehensive investigation on coal fracture properties concerned with gas seepage Evolution of coal fracture orientation distribution with tectonism Connectivity evolution with tectonism [ABSTRACT FROM AUTHOR]

The internal microstructures of Ni–P-plated Al–Zn–Mg-based alloys were investigated using synchrotron X-ray computed tomography, together with various analytical methods for hydrogen detection. We clarified that hydrogen-induced pores were generated and segregated near the top and bottom surfaces of a rolled sheet of a commercial-purity Al–Zn–Mg-based alloy with Ni–P plating. In contrast, such segregation of hydrogen micropores was not observed in the high-purity-grade Al–Zn–Mg alloys with Ni–P plating. This result suggests that hydrogen enters the Ni–P plating layer during the plating operation and generates pores in the surface region owing to surface inclusions. Additionally, the hydrogen-induced defects deteriorated the tensile properties such as tensile strength and elongation of the commercial-purity Al–Zn–Mg-based alloys containing higher levels of impurities such as Fe and Si with Ni–P plating. [Display omitted] • Internal microstructures of Ni–P-plated Al–Zn–Mg-based alloys investigated. • Synchrotron X-ray computed tomography and hydrogen detection methods were employed. • H enters plating layer and generates surface micropores due to surface inclusions. • H-induced defects deteriorate the tensile properties of the plated pure alloy. [ABSTRACT FROM AUTHOR]

Highlights: 3D hydraulic fractures were extracted from X-ray computed tomography images by manual selection and surface interpolation. Joint roughness was measured for hydraulic fractures induced along different cleavage planes in granite. The cleavage plane and pressurization rate have an effect on the roughness of hydraulically induced fractures. [ABSTRACT FROM AUTHOR]

X-ray cone-beam computed tomography (CBCT) is a powerful tool for nondestructive testing and evaluation, yet the CT image quality can be compromised by artifact due to X-ray scattering within dense materials such as metals. This problem leads to the need for hardware- and software-based scatter artifact correction to enhance the image quality. Recently, deep learning techniques have merged as a promising approach to obtain scatter-free images efficiently. However, these deep learning techniques rely heavily on training data, often gathered through simulation. Simulated CT images, unfortunately, do not accurately reproduce the real properties of objects, and physically accurate X-ray simulation still requires significant computation time, hindering the collection of a large number of CT images. To address these problems, we propose a deep learning framework for scatter artifact correction using projections obtained solely by real CT scanning. To this end, we utilize a beam-hole array (BHA) to block the X-rays deviating from the primary beam path, thereby capturing scatter-free X-ray intensity at certain detector pixels. As the BHA shadows a large portion of detector pixels, we incorporate several regularization losses to enhance the training process. Furthermore, we introduce radiographic data augmentation to mitigate the need for long scanning time, which is a concern as CT devices equipped with BHA require two series of CT scans. Experimental validation showed that the proposed framework outperforms a baseline method that learns simulated projections where the entire image is visible and does not contain scattering artifacts. [ABSTRACT FROM AUTHOR]

Flat objects like electronic boards are challenging samples for high-resolution X-ray computed tomography scanning because their largest dimension significantly limits the magnification using circular trajectory scans. One way to improve spatial resolution for such samples is to utilize variable zoom trajectory. During variable zoom trajectory scanning, the source-to-object distance changes during the 360° rotation to maximize the magnification in the projections. Here, we propose an automatic variable zoom trajectory generation algorithm for arbitrary object and region of interest (ROI). We analyze how such a trajectory can enhance resolution in different cases and how isotropic is the resolution in the reconstructed volume. We demonstrate that the resolution can be improved without destroying the sample. However, the improvement is manifested mainly in directions in which we achieved the highest magnification in the projection. [ABSTRACT FROM AUTHOR]

The non‐destructive inspection of Printed Circuit Boards (PCBs) through r‐ray Computer Tomography (CT) is a recently developed method that offers several advantages over traditional inspection techniques. This method is non‐invasive, quick, and offers high resolution, leading to significant improvements in inspection and repair efficiency. Post‐image analysis is an important step in PCB inspection and has important practical significance for automatic positioning and determining the location of faults. Usually, the results of image segmentation are an important basis for PCB defect detection, and accurate segmentation results can effectively improve the efficiency and accuracy of PCB inspection and increase the level of automation. This paper discusses two innovative improvements for the automatic segmentation process: firstly determining which slices of an x‐ray CT 3D PCB stack belong to which layer on a physical PCB in an automatic, generic and completely unsupervised way, which is verified on a 4‐layer PCB; secondly proposing a level set‐based image segmentation algorithm for the problem of gray scale inhomogeneity present in PCB CT. Experimental results on real PCB CT images with high aliasing and artifacts show that the proposed model can obtain better performance than the popular active contour models. [ABSTRACT FROM AUTHOR]

Defects shape, volume, and orientation all have a direct impact on the mechanical properties of Laser Powder Bed Fused (L-PBF-ed) parts. Therefore, it is necessary to evaluate and analyze the three-dimensional (3D) geometrical characteristics of these defects. X-ray Computed Tomography (XCT) can reveal an object's internal structure by volumetric scanning through its building direction. Point clouds are 3D data that can be extracted from the stack of XCT images taken from a part to perform further analysis. This study presents a novel approach for 3D segmentation and geometrical analysis of L-PBF defect structures from XCT images. The proposed method integrates Voronoi labeling and 3D point cloud reconstruction to reveal individual defect characteristics from the XCT image stack of a part. A case study showed the proposed methodology's effectiveness in identifying and characterizing defect regions in L-PBF-ed Cobalt-Chrome (CoCr) parts. [ABSTRACT FROM AUTHOR]

Objectives: Utilising readily available clinical variables, we aimed to develop and validate a novel machine learning (ML) model to predict severe coronary calcification, and further assessed its prognostic significance. Methods: This retrospective study enrolled patients who underwent coronary CT angiography and subsequent invasive coronary angiography. Multiple ML algorithms were used to train the models for predicting severe coronary calcification (cardiac CT-measured coronary artery calcium [CT-CAC] score ≥ 400). The ML-based CAC (ML-CAC) score derived from the ML predictive probability was stratified into quartiles for prognostic analysis. The primary endpoint was a composite of all-cause death, nonfatal myocardial infarction, or nonfatal stroke. Results: Overall, 5785 patients were divided into training (80%) and test sets (20%). For clinical practicability, we selected the nine-feature support vector machine model with good and satisfactory performance regarding both discrimination and calibration based on five repetitions of the 10-fold cross-validation in the training set (mean AUC = 0.715, Brier score = 0.202), and based on the test in the test set (AUC = 0.753, Brier score = 0.191). In the test set cohort (n = 1137), the primary endpoint was observed in 50 (4.4%) patients during a median 2.8 years' follow-up. The ML-CAC system was significantly associated with an increased risk of the primary endpoint (adjusted hazard ratio for trend 2.26, 95% CI 1.35–3.79, p = 0.002). There was no significant difference in the prognostic value between the ML-CAC and CT-CAC systems (C-index, 0.67 vs. 0.69; p = 0.618). Conclusion: ML-CAC score predicted from clinical variables can serve as a novel prognostic indicator in patients referred for invasive coronary angiography. Clinical relevance statement: In patients referred for invasive coronary angiography who have not undergone preoperative CT-measured coronary artery calcium scoring, machine learning–based coronary artery calcium score assessment can serve as an alternative for predicting the prognosis. Key Points: • The coronary artery calcium (CAC) score, a solid prognostic indicator, can be predicted using non-CT methods. • We developed a machine learning (ML)-CAC model utilising nine clinical variables to predict severe coronary calcification. • The ML-CAC system offers significant prognostic value in patients referred for invasive coronary angiography. [ABSTRACT FROM AUTHOR]

Background: The surface brittle fracture of cermet coating seriously restricts its application. Accurate evaluation of the fracture toughness of cermet coating is a prerequisite for improving its life. Objective: This paper aims to propose an accurate characterization method for fracture toughness of cermet coating. Methods: By coupling instrumented indentation and X‑ray computed tomography (XCT), the indentation-induced fracture behaviors under various loads within WC-12%Co coatings were studied. The three-dimensional subsurface crack morphologies and the damage evolution within the coating were nondestructively observed by XCT. The indentation response was correlated with the damage evolution. The impact of substrate effects on indentation-induced fracture behaviors was further studied using finite element analysis (FEA). Results: The Palmqvist shape of the indentation crack under low loads was successfully identified. The first pop-in event in the load-displacement (P-h) curve was determined to be triggered by bottom cracking, marking the onset of the multiple fracture mode. Laugier's equation offered a stable and reliable estimation of fracture toughness for the coating in the radial cracking mode. Conclusions: XCT plays a crucial role in selecting the appropriate equation for indentation toughness calculation. The critical indentation depth for the first pop-in was suggested as the threshold for reliably extracting intrinsic fracture toughness of cermet coatings. Numerical results revealed a constant linear relationship between the critical depth and coating thickness, and a high sensitivity of the critical depth to yield stress of the substrate. The proposed analytical procedure holds potential for generalization to diverse cermet coatings on metal substrates. [ABSTRACT FROM AUTHOR]

Powered by machine learning, computer-aided diagnostics support clinicians by streamlining their work. In cancer screening, for instance, this technique often involves an automated detection of potential cancerous lesions from X-ray Computed Tomography (CT) images reconstructed a priori and unaware of the detection task. Since different reconstruction algorithms enhance different image attributes, a natural question is whether adapting the algorithms to the downstream task is relevant to improving the performance of computer-aided diagnosis tools. This paper provides empirical evidence about the performance of the taskadapted framework for joint reconstruction-segmentation of lung nodules from CT scans. We describe the procedures that allow the joint training of reconstruction and segmentation operators. We also report that relevant segmentation metrics improve by up to twenty percentage points in the four angular-sparsity and X-ray dose settings studied. Finally, we give practical recommendations for the procedure's hyperparameter tuning. Our results suggest that the imaging pipeline could benefit from computing different images adapted to the clinician's eyes and the automatic segmentation tools, outlining future improvements in patient care and clinical tasks. [ABSTRACT FROM AUTHOR]

The structural resolution describes the ability of a measuring device to detect small structures on the surface of a component or test specimen by means of a quantitative value. However, the structural resolution in the computer tomograph depends on the object and must therefore be determined separately for each measurement task. The previous approaches to structural resolution determination are only related to test specimens. In this paper, less discrete approaches based on a circular pattern are presented, which can be integrated into the measured component. A voxel-based methodology as well as two surface-based methodologies are described. The investigation results regarding the effect of the component position on the structural resolution are obtained on the basis of real CT measurements. A comparison is also completed with the well-known hourglass method. The results show that the resolution depends on the object being measured, with similar values being obtained for the same object using different methods. [ABSTRACT FROM AUTHOR]

X-ray computed tomography (CT) is a technology that can non-destructively acquire volumetric images of objects. It is the only commercialized and practical measurement of the inner geometry of objects with micrometer-order accuracy. Microfocus X-ray CT scanners have been widely used in several manufacturing industries. The main applications range from typical observation and inspection to precision measurement and geometry acquisition. They are expanding beyond manufacturing (e.g., science, archeology, and food industries). This review describes the requirements for the use of X-ray CT scanners in the manufacturing industry and their modeling techniques. Recently, there have been growing expectations for the introduction of CT scanners for the high-accuracy acquisition of geometry and inline inspection for manufacturing automation. This requires quality and fast measurement data generation and scan data processing methods. Therefore, this paper presents attempts in the field of modeling for this purpose. The latest topics will also be covered, including large-scale CT and 4DCT. [ABSTRACT FROM AUTHOR]

Soil porosity and moisture are critical indicators of soil quality. In coal–grain intercropping areas, centuries of coal industry activities have resulted in coal particle contamination, which has affected soil properties; however, its impact on soil porosity and moisture remains underexplored. This study compares coal-contaminated soils (CCS) and coal-free soils (CFS) in Jiaozuo, employing computed tomography (CT) scanning and moisture measurements to analyze how coal pollution influences soil porosity and moisture. Our findings indicate that CCS, compared to CFS, exhibit significant reductions in total porosity (TP), CT-measured porosity (CTP), number of pores (CTN), and the proportion and volume of water–air regulating pores (CTNWA/CTN and CTPWA). These results underscore that coal pollution substantially alters soil porosity and pore numbers. Additionally, coal pollution modifies soil pore morphology, leading to reductions in the number and length of pore throats (Nthroat and Lthroat) and causing the pores to become more flattened and rounded, with an increased inclination angle of interconnected pores (IAic). As coal pollution levels increase, interconnected porosity (Pic) and coordination number (CNic) decrease, while isolated porosity (Pisolated) increases. In terms of moisture parameters, coal pollution diminishes the maximum water holding capacity, soil permanent wilting point, saturated hydraulic conductivity, and moisture evaporation rate. In contrast, field water-holding capacity and maximum effective water content are enhanced. Furthermore, with increased coal pollution, maximum water holding capacity, soil permanent wilting point, and saturated hydraulic conductivity decreased, whereas field water-holding capacity and maximum effective water content increased. Correlation analysis reveals that changes in CTN, Nthroat, and Lthroat significantly influence moisture parameter variations, with most pore parameter changes affecting saturated hydraulic conductivity. The observed effects of coal pollution on soil pore parameters are attributed to the filling and clogging actions of coal particles, while its impact on moisture parameters primarily results from these particles filling and clogging soil pores. This study provides a scientific basis for managing soil moisture in areas affected by coal pollution, particularly in coal–grain intercropping regions. [ABSTRACT FROM AUTHOR]

Temporary metal implants, made from materials like titanium (Ti) or stainless steel, can cause metabolic issues, raise toxicity levels within the body, and negatively impact the patient's long-term health. This necessitates a subsequent operation to extract these implants once the healing process is complete or when they are outgrown by the patient. In contrast, medical devices fabricated from absorbable alloys have the advantage of being biodegradable, allowing them to be naturally absorbed by the body once they have fulfilled their role in facilitating tissue healing. Among the various absorbable alloy systems studied, magnesium (Mg) alloys stand out due to their biocompatibility, mechanical properties, and corrosion behavior. The existing literature on absorbable Mg alloys highlights the effectiveness of silicon (Si) and zinc (Zn) additions in improving mechanical properties and controlling corrosion susceptibility; however, there is a lack of comprehensive quantitative morphological analysis of the intermetallic phases within these alloy systems. The quantification of the complex morphology of intermetallic particles is a challenging task and has significant implications for the micromechanical properties of the alloys. This study, therefore, aims to introduce a robust set of morphometric parameters for evaluating the morphology of intermetallic phases within two as-cast Mg alloys with Si and Zn additions. X-ray Computed Tomography (XCT) was used to capture the 3D tomographic data of the alloys, and a novel pair of morphological parameters (ratio of convex hull to particle volume and convex hull sphericity) was applied to the 3D tomographic data to assess the MgZn phase formed in the two alloys. In addition to the impact of composition, the effect of solidification rate on the morphological parameters was also studied. Furthermore, Scanning Electron Microscopy (SEM) and Energy-Dispersive Spectroscopy (EDS) were employed to gather detailed 2D microstructural and compositional information on the intermetallics. The comprehensive characterization reveals that the morphological complexity and size distribution of the MgZn phase are influenced by both compositional changes and the solidification rate. However, the change in MgZn intermetallic particle morphology with size was found to follow a predictable trend, which was relatively agnostic of the chosen casting conditions. [ABSTRACT FROM AUTHOR]

Abstract X-Ray micro-computed tomography (XCT) is used to reveal the micro-structural changes of banana pseudostem nanocellulose bioplastic due to a biodegradation process initiated in a formulated composting media that allowed the growth of aerobic microflora. The bioplastic itself was made of nanocellulose, which was isolated from banana pseudostem using the 2,2,6,6-Tetramethyl-1-piperidinyloxy (TEMPO) mediated oxidation method, and polyethylene glycol (PEG) as plasticiser. XCT provided insights into the 3D structural change of the bioplastic identifying the degradation process at two scales. The results showed that the local thickness and roughness of the bioplastic increased after degradation, while the density of the material decreased. Enlarged voids and tunnels were observed in the material after degradation. The formation of these tunnels is attributed to the popping of internal PEG-containing voids because of the generation of gases, which after forming may further accelerate biodegradation by microbial activity.

Abstract The purpose of this study is to develop a nomogram model for early prediction of the severe mycoplasma pneumoniae pneumonia (SMPP) in Pediatric and Adult Patients. A retrospective analysis was conducted on patients with MPP, classifying them into SMPP and non-severe MPP (NSMPP) groups. A total of 550 patients (NSMPP 374 and SMPP 176) were enrolled in the study and allocated to training, validation cohorts. 278 patients (NSMPP 224 and SMPP 54) were retrospectively collected from two institutions and allocated to testing cohort. The risk factors for SMPP were identified using univariate analysis. For radiomic feature selection, Spearman’s correlation and the least absolute shrinkage and selection operator (LASSO) were utilized. Logistic regression was used to build different models, including clinical, imaging, radiomics, and integrated models (combining clinical, imaging, and radiomics features selected). The model’s discrimination was evaluated using a receiver operating characteristic curve, its calibration with a calibration curve, and the results were visualized using the Hosmer–Lemeshow goodness-of-fit test. Thirteen clinical features and fourteen imaging features were selected for constructing the clinical and imaging models. Simultaneously, a set of twenty-five radiomics features were utilized to build the radiomics model. The integrated model demonstrated good calibration and discrimination in the training cohorts (AUC, 0.922; 95% CI: 0.900, 0.942), validation cohorts (AUC, 0.879; 95% CI: 0.806, 0.920), and testing cohorts (AUC, 0.877; 95% CI: 0.836, 0.916). The discriminatory and predictive efficacy of the clinical model in testing cohorts increased further after clinical and radiological features were incorporated (AUC, 0.849 vs. 0.922, P = 0.002). The model demonstrated exemplary predictive efficacy for SMPP by leveraging a comprehensive set of inputs, encompassing clinical data, quantitative and qualitative radiological features, along with radiomics features. The integration of these three aspects in the predictive model further enhanced the performance of the clinical model, indicating the potential for extensive clinical applications.

Introduction. When studying composite materials for construction purposes, it is needed to consider the mechanisms of formation of the structure and properties of modern concretes in the process of strength development. In studies of modern composite materials based on cement binder, there is no information about the development of structural defects and destruction of the material at the initial stages of strength development. This information can be obtained using X-ray computed tomography, a promising method of nondestructive testing of the state of the material. Therefore, the objective of this work was to study the formation and propagation of cracks in samples of fine-grained concrete with different fractional composition of sand due to natural processes of cement shrinkage, as well as the mechanics of destruction of samples of modified fine-grained concrete when applying a compressive load at the early stages of strength development. Materials and Methods. The study used fine-grained concrete mixtures of three compositions with different sand gradation. The tomography samples were made by placing fresh mixtures in polymer cylindrical containers. Tomography of the samples immediately after manufacture, as well as after 8 and 51 days, was performed in a YXLON Cheetah microfocus X-ray machine. The composition with two-fraction sand was modified by mechanical activation of the components, 20×20×20 mm cube samples were made. Further, compression tests were performed at the Instron installation after 3 and 7.5 hours, and then — tomography of the destroyed samples.Results. It was established that the destruction of contact zones depended on the ratio of the size of the fractions. In the presence of a bulk of coarse sand grains in concrete, the destruction of contact zones was more pronounced and had a main mode. When using fine or polyfraction sand, contact zones were destroyed locally and had a visually smaller area. The images of the destroyed modified sample, tested 3 hours after manufacturing, showed clear cracks and indents on the edges, which indicated the elastic-plastic nature of the destruction. In 7.5 hours, the edges of the sample upon destruction were covered with a network of small cracks; inside the sample there were also numerous cracks and microcracks, which indicated brittle fracture. Based on the obtained images of the deformed structure of modified concrete, the mechanism of transition from elastic-plastic destruction of the material to brittle one was clearly visible.Discussion and Conclusion. The studied dependences of the influence of the size of fine aggregate on the mechanisms of formation and propagation of structural defects contribute to the theory of the processes of destruction of fine-grained concretes. The results obtained prove the prospects of using X-ray computed tomography as a method of nondestructive testing of the internal structure of fine-grained concrete, including at the early stages of strength development.

The structural resolution describes the ability of a measuring device to detect small structures on the surface of a component or test specimen by means of a quantitative value. However, the structural resolution in the computer tomograph depends on the object and must therefore be determined separately for each measurement task. The previous approaches to structural resolution determination are only related to test specimens. In this paper, less discrete approaches based on a circular pattern are presented, which can be integrated into the measured component. A voxel-based methodology as well as two surface-based methodologies are described. The investigation results regarding the effect of the component position on the structural resolution are obtained on the basis of real CT measurements. A comparison is also completed with the well-known hourglass method. The results show that the resolution depends on the object being measured, with similar values being obtained for the same object using different methods.

Soil organic matter and pores distribution within aggregates were studied using X-ray computed tomography (XCT; Nikon XT H 225ST and GE Phoenix L240) and advanced 2D/3D measurements by the digital Keyence VHX-6000 microscope (Japan). A new methodological approach with computed tomography involvement for studying the spatial arrangement of pores, porosity, and soil morphology is presented. Changes in studied parameters are documented along the transect of intensively used Haplic Chernozem. Soil disturbance due to erosion and colluvial soil profile formation is reported. Moreover, soil organic matter quality and aggregate stability were evaluated. Obtained results showed statistically significant differences between the control and eroded sites and between eroded and accumulated sites. The correlation coefficients were the highest for soil organic carbon (SOC) and humic substances CHS (r = 0.805) and CHS and CHA/CFA (r = 0.764). The highest porosity, aggregates stability and coefficients stability were confirmed on the eroded site. The computed tomography measurements also document the high disturbance of Haplic Chernozem on the control site and the newly formed profile of Colluvisol. Despite excellent complementary technique further research is necessary to improve micro-XCT resolution and capacity for the soil micromorphological study.

In X-ray Computed Tomography (XCT) geometric measurement, the reconstruction process is a main step that significantly influences acquisition strategies and measurement results. Analytical algorithms, primarily Feldkamp-Davis-Kress (FDK), and algebraic algorithms are commonly used for reconstruction, with FDK being the dominant choice for dimensional measurements. Although algebraic algorithms offer advantages like denoising and handling limited projections, their evaluation concerning measurement accuracy remains insufficient. To assess the performance with respect to measurement accuracy and sensitivity to acquisition parameters, we performed typical reconstruction algorithms on the measurements of diameter, cylindricity, and flatness, including FDK and ordered subsets simultaneously algebraic reconstruction technique (OS-SART). Moreover, the algorithm comprised in a commercial software was used and evaluated. Variables in acquisition included part orientation and exposure time. The analysis comparing XCT measurements with those from Coordinate Measuring Machine showed different performances of the two reconstruction algorithms and the potential of algebraic algorithms in XCT geometric measurement. [ABSTRACT FROM AUTHOR]

Accurate three‐dimensional (3D) reconstruction of granular grains from x‐ray micro‐computed tomography (µCT) images is a long‐standing challenge, particularly for dense soil samples. This study develops a machine learning (ML) enhanced approach to automatically reconstruct granular grains from µCT images. The novel academic contributions of this paper include (a) a hierarchical strategy based on parameter‐independent polygonal approximation, area, and concavity analysis, for the first time, to identify and eliminate both intergranular and intragranular voids; (b) incorporation of a recursive segmentation scheme and ML‐based grain classifier to avoid over‐segmentation; (c) novel modifications on the determination of splitting paths to enhance segmentation accuracy; and (d) an effective approach of assigning initial level set functions for reconstructing granular grains automatically. The hybrid ML algorithm is applied to µCT images of dense Mojave Mars Simulant. The results indicate that the proposed method can accurately segment grain clumps with unclear boundaries. The new automatic reconstruction algorithm eliminates ineffective operations and achieves a three‐fold increase in computational speed than previous methods documented in the literature. Ninety‐one percent of grains with distinct boundaries can be reconstructed and the reconstruction ratio reaches 81% even for grains without distinct boundaries. The overall reconstruction ratio of grains increases by 20% compared with previous methods, achieving a step‐change improvement for one‐to‐one mapping of real soil samples. [ABSTRACT FROM AUTHOR]

Understanding ethnic variations in body composition is crucial for assessing health risks. Universal models may not suit all ethnicities, and there is limited data on the Inuit population. This study aimed to compare body composition between Inuit and European adults using computed tomography (CT) scans and to investigate the influence of demographics on these measurements. A retrospective analysis was conducted on 50 adults (29 Inuit and 21 European) who underwent standard trauma CT scans. Measurements focused on skeletal muscle index (SMI), various fat indices, and densities at the third lumbar vertebra level, analyzed using the Wilcoxon-Mann-Whitney test and multiple linear regression. Inuit women showed larger fat tissue indices and lower muscle and fat densities than European women. Differences in men were less pronouncehd, with only Intramuscular fat density being lower among Inuit men. Regression indicated that SMI was higher among men, and skeletal muscle density decreased with Inuit ethnicity and age, while visceral fat index was positively associated with age. This study suggests ethnic differences in body composition measures particularly among women, and indicates the need for Inuit-specific body composition models. It highlights the importance of further research into Inuit-specific body composition measurements for better health risk assessment. [ABSTRACT FROM AUTHOR]

Abstract Although the origins of lost wax casting extend back into the 5th millennium BCE, it was not until the development of hollow core casting that life-sized metal sculptures could be produced. Based on existing evidence, the earliest adoption of this technique, which involves the inclusion of a clay core within a wax model, occurred in Iraq (Mesopotamia) during the Early Dynastic III period (ca. 2600–2350 BCE). To date, only one hollow core casting from the succeeding Akkadian period (ca. 2350–2150 BCE)—the Sargon Head in the collection of the Iraq Museum—has been studied from a technical point of view. The recent attribution of The Metropolitan Museum of Art's Head of a ruler to this formative period of hollow core lost wax casting provided the impetus for its examination by high-energy X-ray computed tomography—the most practical technique for an object that is continuously on display that could image in 3D the interior morphology of this sculpture given the considerable thickness of its metal walls. This scan revealed a markedly different style of production than the Sargon Head. Although further research on early castings is required to determine the chronological implications of the differences observed and to elucidate more generally the early development of hollow casting technology, the scan of the Head of a ruler provides evidence of some of the challenges encountered and problem-solving strategies used in the casting process.

Abstract Objective To conduct a bibliometric analysis of the prospects and obstacles associated with dual- and multi-energy CT in thoracic disease, emphasizing its current standing, advantages, and areas requiring attention. Methods The Web of Science Core Collection was queried for relevant publications in dual- and multi-energy CT and thoracic applications without a limit on publication date or language. The Bibliometrix packages, VOSviewer, and CiteSpace were used for data analysis. Bibliometric techniques utilized were co-authorship analyses, trend topics, thematic map analyses, thematic evolution analyses, source’s production over time, corresponding author’s countries, and a treemap of authors’ keywords. Results A total of 1992 publications and 7200 authors from 313 different sources were examined in this study. The first available document was published in November 1982, and the most cited article was cited 1200 times. Siemens AG in Germany emerged as the most prominent author affiliation, with a total of 221 published articles. The most represented scientific journals were the “European Radiology” (181 articles, h-index = 46), followed by the “European Journal of Radiology” (148 articles, h-index = 34). Most of the papers were from Germany, the USA, or China. Both the keyword and topic analyses showed the history of dual- and multi-energy CT and the evolution of its application hotspots in the chest. Conclusion Our study illustrates the latest advances in dual- and multi-energy CT and its increasingly prominent applications in the chest, especially in lung parenchymal diseases and coronary artery diseases. Photon-counting CT and artificial intelligence will be the emerging hot technologies that continue to develop in the future. Critical relevance statement This study aims to provide valuable insights into energy-based imaging in chest disease, validating the clinical application of multi-energy CT together with photon-counting CT and effectively increasing utilization in clinical practice. Key Points Bibliometric analysis is fundamental to understanding the current and future state of dual- and multi-energy CT. Research trends and leading topics included coronary artery disease, pulmonary embolism, and radiation dose. All analyses indicate a growing interest in the use of energy-based imaging techniques for thoracic applications. Graphical Abstract

Objective: This study aimed to analyze the factors influencing artificial intelligence (AI) diagnostic system detection of pulmonary nodules on computed tomography (CT) scans, using a chest simulation phantom experiment with simulated lung nodules. Methods: A Toshiba (Canon) 64-slice spiral CT scanner was used. The phantom was scanned and images were reconstructed under varying scanning parameters (dose, reconstruction algorithm, and layer thickness) and non-scanning parameters (nodule size, density, and chest location). Subsequently, the AI diagnostic system performed pulmonary nodule detection on the images. Results: (1) No statistically significant difference was observed in the true positive rate of pulmonary nodules detected at different scanning doses. However, the low-dose mode produced a higher number of false positives. (2) Comparisons across the three iterative reconstruction algorithms revealed no statistically significant difference in the true positive rate of detected pulmonary nodules. However, the Strong group exhibited a higher true positive rate and a higher number of false positives. (3) The true positive rate of lung nodules detected in thin images was significantly higher than in thick images. (4) The true positive rate of pulmonary nodules located in the paramediastinum was significantly higher in the subpleural and lung parenchyma. (5) The true positive rate of nodules ≥8 mm was significantly higher than that of nodules ≤5 mm. (6) No statistically significant difference was observed in the true positive rate when detecting nodules with differing densities. Conclusion: Both CT scanning parameters (dose, reconstruction algorithm, and layer thickness) and non-scanning parameters (nodule size, density, and chest location) can influence the detection of pulmonary nodules by AI systems.

Abstract Objective This study developed and validated a nomogram utilizing clinical and multi-slice spiral computed tomography (MSCT) features for the preoperative prediction of Ki-67 expression in stage IA lung adenocarcinoma. Additionally, we assessed the predictive accuracy of Ki-67 expression levels, as determined by our model, in estimating the prognosis of stage IA lung adenocarcinoma. Materials and methods We retrospectively analyzed data from 395 patients with pathologically confirmed stage IA lung adenocarcinoma. A total of 322 patients were divided into training and internal validation groups at a 6:4 ratio, whereas the remaining 73 patients composed the external validation group. According to the pathological results, the patients were classified into high and low Ki-67 labeling index (LI) groups. Clinical and CT features were subjected to statistical analysis. The training group was used to construct a predictive model through logistic regression and to formulate a nomogram. The nomogram’s predictive ability and goodness-of-fit were assessed. Internal and external validations were performed, and clinical utility was evaluated. Finally, the recurrence-free survival (RFS) rates were compared. Results In the training group, sex, age, tumor density type, tumor-lung interface, lobulation, spiculation, pleural indentation, and maximum nodule diameter differed significantly between patients with high and low Ki-67 LI. Multivariate logistic regression analysis revealed that sex, tumor density, and maximum nodule diameter were significantly associated with high Ki-67 expression in stage IA lung adenocarcinoma. The calibration curves closely resembled the standard curves, indicating the excellent discrimination and accuracy of the model. Decision curve analysis revealed favorable clinical utility. Patients with a nomogram-predicted high Ki-67 LI exhibited worse RFS. Conclusion The nomogram utilizing clinical and CT features for the preoperative prediction of Ki-67 expression in stage IA lung adenocarcinoma demonstrated excellent performance, clinical utility, and prognostic significance, suggesting that this nomogram is a noninvasive personalized approach for the preoperative prediction of Ki-67 expression.

Although the origins of lost wax casting extend back into the 5th millennium BCE, it was not until the development of hollow core casting that life-sized metal sculptures could be produced. Based on existing evidence, the earliest adoption of this technique, which involves the inclusion of a clay core within a wax model, occurred in Iraq (Mesopotamia) during the Early Dynastic III period (ca. 2600–2350 BCE). To date, only one hollow core casting from the succeeding Akkadian period (ca. 2350–2150 BCE)—the Sargon Head in the collection of the Iraq Museum—has been studied from a technical point of view. The recent attribution of The Metropolitan Museum of Art's Head of a ruler to this formative period of hollow core lost wax casting provided the impetus for its examination by high-energy X-ray computed tomography—the most practical technique for an object that is continuously on display that could image in 3D the interior morphology of this sculpture given the considerable thickness of its metal walls. This scan revealed a markedly different style of production than the Sargon Head. Although further research on early castings is required to determine the chronological implications of the differences observed and to elucidate more generally the early development of hollow casting technology, the scan of the Head of a ruler provides evidence of some of the challenges encountered and problem-solving strategies used in the casting process. [ABSTRACT FROM AUTHOR]

Background: Malignant pleural effusion (MPE) is a common clinical problem that requires cytological and/or histological confirmation obtained by invasive examination to establish a definitive diagnosis. Radiomics is rapidly evolving and can provide a non-invasive tool to identify MPE. Objectives: We aimed to develop a model based on radiomic features extracted from unenhanced chest computed tomography (CT) images and investigate its value in predicting MPE. Method: This retrospective study included patients with pleural effusions between January 2016 and June 2020. All patients underwent a chest CT scanning and medical thoracoscopy after artificial pneumothorax. Cases were divided into a training cohort and a test cohort for modelling and verifying respectively. The Mann-Whitney U test and the least absolute shrinkage and selection operator (LASSO) were applied to determine the optimal features. We built a radiomics model based on support vector machines (SVM) and evaluated its performance using ROC and calibration curve analysis. Results: Twenty-nine patients with MPE and fifty-two patients with non-MPE were enrolled. A total of 944 radiomic features were quantitatively extracted from each sample and reduced to 14 features for modeling after selection. The AUC of the radiomics model was 0.96 (95% CI: 0.912-0.999) and 0.86 (95% CI: 0.657~1.000) in the training and test cohorts, respectively. The calibration curves for model were in good agreement between predicted and actual data. Conclusions: The radiomics model based on unenhanced chest CT has good performance for predicting MPE and may provide a powerful tool for doctors in clinical decision-making. [ABSTRACT FROM AUTHOR]

Objective: To conduct a bibliometric analysis of the prospects and obstacles associated with dual- and multi-energy CT in thoracic disease, emphasizing its current standing, advantages, and areas requiring attention. Methods: The Web of Science Core Collection was queried for relevant publications in dual- and multi-energy CT and thoracic applications without a limit on publication date or language. The Bibliometrix packages, VOSviewer, and CiteSpace were used for data analysis. Bibliometric techniques utilized were co-authorship analyses, trend topics, thematic map analyses, thematic evolution analyses, source's production over time, corresponding author's countries, and a treemap of authors' keywords. Results: A total of 1992 publications and 7200 authors from 313 different sources were examined in this study. The first available document was published in November 1982, and the most cited article was cited 1200 times. Siemens AG in Germany emerged as the most prominent author affiliation, with a total of 221 published articles. The most represented scientific journals were the "European Radiology" (181 articles, h-index = 46), followed by the "European Journal of Radiology" (148 articles, h-index = 34). Most of the papers were from Germany, the USA, or China. Both the keyword and topic analyses showed the history of dual- and multi-energy CT and the evolution of its application hotspots in the chest. Conclusion: Our study illustrates the latest advances in dual- and multi-energy CT and its increasingly prominent applications in the chest, especially in lung parenchymal diseases and coronary artery diseases. Photon-counting CT and artificial intelligence will be the emerging hot technologies that continue to develop in the future. Critical relevance statement: This study aims to provide valuable insights into energy-based imaging in chest disease, validating the clinical application of multi-energy CT together with photon-counting CT and effectively increasing utilization in clinical practice. Key Points: Bibliometric analysis is fundamental to understanding the current and future state of dual- and multi-energy CT. Research trends and leading topics included coronary artery disease, pulmonary embolism, and radiation dose. All analyses indicate a growing interest in the use of energy-based imaging techniques for thoracic applications. [ABSTRACT FROM AUTHOR]

Micro-Computed Tomography (µCT) systems are used for examining the internal structures of various objects, such as material samples, manufactured parts, and natural objects. Resolving fine details or performing accurate geometric measurements in the voxel data critically depends on the precise calibration of the µCT systems geometry. This paper presents a calibration method for µCT systems using projections of a calibration phantom, where the coordinates of the phantom are initially unknown. The approach involves detecting and tracking steel ball bearings and adjusting the unknown system geometry parameters using non-linear least squares optimization. Multiple geometric models are tested to verify their suitability for a self-calibration approach. The implementation is tested using a calibration phantom captured at different magnifications. The results demonstrate the system's capability to determine the geometry model parameters with a remaining error on the detector between 0.27 px and 0.18 px. Systematic errors that remain after calibration, as well as changing parameters due to system instabilities, are investigated. The source code of this work is published to enable further research. [ABSTRACT FROM AUTHOR]

Bristlecone pine (Pinus longaeva) (PILO) trees exhibit exceptional longevity. Their tree‐ring width (TRW) series offer valuable insights into climatic variability. Maximum latewood density (MXD) typically correlates better with temperature variations than TRW, yet PILO MXD records are non‐existent due to methodological challenges related to tree‐ring structure. Here, we used an X‐ray Computed Tomography (X‐ray CT) toolchain on 51 PILO cores from the California White Mountains to build a chronology that correlates significantly (r = 0.66, p < 0.01) with warm‐season (March‐September) temperature over a large spatial extent. This led to the first X‐ray CT‐based temperature reconstruction (1625–2005 CE). Good reconstruction skill (RE = 0.51, CE = 0.32) shows that extending MXD records across the full length of the PILO archive could yield a robust warm‐season temperature proxy for the American Southwest over millennia. This breakthrough opens avenues for measuring MXD in other challenging conifers, increasing our understanding of past climate further, particularly in lower latitudes. Plain Language Summary: Ancient Bristlecone pine trees can live for several millennia and hold invaluable climate information. Their annual rings were used to develop millennium‐length records of the Holocene climate. Maximum latewood density (MXD), which is the highest wood density value in the latewood of a tree ring, has been shown to closely follow summer temperature in different conifer species, but not yet in Bristlecone pine. The gnarly and twisted growth of these ancient trees has presented significant hurdles for MXD analysis. Here we apply an X‐ray Computed Tomography toolchain that allows us to 3D scan through the tissue of a tree ring and to map MXD variations. Using this new technique, we were able to reconstruct warm‐season temperature for the American Southwest back to 1625 CE. With these findings, we are confident that a full‐length reconstruction (back to 2575 BCE) can yield the longest annually resolved temperature reconstruction for this continent. Key Points: We present the first X‐ray Computed Tomography‐derived maximum latewood density‐based temperature reconstruction using Bristlecone pine tree coresBristlecone pine maximum latewood density is a reliable proxy for warm‐season temperature over a large part of the American SouthwestOur reconstruction (1625–2005 CE) contains low‐frequency variability and can be prolonged over a large part of the Holocene [ABSTRACT FROM AUTHOR]